From f72c2db47080523d5e0f3c20846c96ed31c35648 Mon Sep 17 00:00:00 2001
From: Danilo Krummrich <dakr@redhat.com>
Date: Wed, 20 Sep 2023 16:42:34 +0200
Subject: [PATCH] drm/gpuvm: rename struct drm_gpuva_manager to struct
 drm_gpuvm
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Rename struct drm_gpuva_manager to struct drm_gpuvm including
corresponding functions. This way the GPUVA manager's structures align
very well with the documentation of VM_BIND [1] and VM_BIND locking [2].

It also provides a better foundation for the naming of data structures
and functions introduced for implementing a common dma-resv per GPU-VM
including tracking of external and evicted objects in subsequent
patches.

[1] Documentation/gpu/drm-vm-bind-async.rst
[2] Documentation/gpu/drm-vm-bind-locking.rst

Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Acked-by: Dave Airlie <airlied@redhat.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230920144343.64830-2-dakr@redhat.com
---
 drivers/gpu/drm/Makefile                      |   2 +-
 drivers/gpu/drm/drm_debugfs.c                 |  16 +-
 .../gpu/drm/{drm_gpuva_mgr.c => drm_gpuvm.c}  | 404 +++++++++---------
 drivers/gpu/drm/nouveau/nouveau_exec.c        |   2 +-
 drivers/gpu/drm/nouveau/nouveau_uvmm.c        |  28 +-
 drivers/gpu/drm/nouveau/nouveau_uvmm.h        |   6 +-
 include/drm/drm_debugfs.h                     |   6 +-
 include/drm/{drm_gpuva_mgr.h => drm_gpuvm.h}  | 155 ++++---
 8 files changed, 309 insertions(+), 310 deletions(-)
 rename drivers/gpu/drm/{drm_gpuva_mgr.c => drm_gpuvm.c} (78%)
 rename include/drm/{drm_gpuva_mgr.h => drm_gpuvm.h} (78%)

--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -45,7 +45,7 @@ drm-y := \
 	drm_vblank.o \
 	drm_vblank_work.o \
 	drm_vma_manager.o \
-	drm_gpuva_mgr.o \
+	drm_gpuvm.o \
 	drm_writeback.o
 drm-$(CONFIG_DRM_LEGACY) += \
 	drm_agpsupport.o \
--- a/drivers/gpu/drm/drm_debugfs.c
+++ b/drivers/gpu/drm/drm_debugfs.c
@@ -40,7 +40,7 @@
 #include <drm/drm_file.h>
 #include <drm/drm_gem.h>
 #include <drm/drm_managed.h>
-#include <drm/drm_gpuva_mgr.h>
+#include <drm/drm_gpuvm.h>
 
 #include "drm_crtc_internal.h"
 #include "drm_internal.h"
@@ -182,31 +182,31 @@ static const struct file_operations drm_
 /**
  * drm_debugfs_gpuva_info - dump the given DRM GPU VA space
  * @m: pointer to the &seq_file to write
- * @mgr: the &drm_gpuva_manager representing the GPU VA space
+ * @gpuvm: the &drm_gpuvm representing the GPU VA space
  *
  * Dumps the GPU VA mappings of a given DRM GPU VA manager.
  *
  * For each DRM GPU VA space drivers should call this function from their
  * &drm_info_list's show callback.
  *
- * Returns: 0 on success, -ENODEV if the &mgr is not initialized
+ * Returns: 0 on success, -ENODEV if the &gpuvm is not initialized
  */
 int drm_debugfs_gpuva_info(struct seq_file *m,
-			   struct drm_gpuva_manager *mgr)
+			   struct drm_gpuvm *gpuvm)
 {
-	struct drm_gpuva *va, *kva = &mgr->kernel_alloc_node;
+	struct drm_gpuva *va, *kva = &gpuvm->kernel_alloc_node;
 
-	if (!mgr->name)
+	if (!gpuvm->name)
 		return -ENODEV;
 
 	seq_printf(m, "DRM GPU VA space (%s) [0x%016llx;0x%016llx]\n",
-		   mgr->name, mgr->mm_start, mgr->mm_start + mgr->mm_range);
+		   gpuvm->name, gpuvm->mm_start, gpuvm->mm_start + gpuvm->mm_range);
 	seq_printf(m, "Kernel reserved node [0x%016llx;0x%016llx]\n",
 		   kva->va.addr, kva->va.addr + kva->va.range);
 	seq_puts(m, "\n");
 	seq_puts(m, " VAs | start              | range              | end                | object             | object offset\n");
 	seq_puts(m, "-------------------------------------------------------------------------------------------------------------\n");
-	drm_gpuva_for_each_va(va, mgr) {
+	drm_gpuvm_for_each_va(va, gpuvm) {
 		if (unlikely(va == kva))
 			continue;
 
--- a/drivers/gpu/drm/drm_gpuva_mgr.c
+++ /dev/null
@@ -1,1723 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Copyright (c) 2022 Red Hat.
- *
- * Permission is hereby granted, free of charge, to any person obtaining a
- * copy of this software and associated documentation files (the "Software"),
- * to deal in the Software without restriction, including without limitation
- * the rights to use, copy, modify, merge, publish, distribute, sublicense,
- * and/or sell copies of the Software, and to permit persons to whom the
- * Software is furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
- * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
- * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
- * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
- * OTHER DEALINGS IN THE SOFTWARE.
- *
- * Authors:
- *     Danilo Krummrich <dakr@redhat.com>
- *
- */
-
-#include <drm/drm_gpuva_mgr.h>
-
-#include <linux/interval_tree_generic.h>
-#include <linux/mm.h>
-
-/**
- * DOC: Overview
- *
- * The DRM GPU VA Manager, represented by struct drm_gpuva_manager keeps track
- * of a GPU's virtual address (VA) space and manages the corresponding virtual
- * mappings represented by &drm_gpuva objects. It also keeps track of the
- * mapping's backing &drm_gem_object buffers.
- *
- * &drm_gem_object buffers maintain a list of &drm_gpuva objects representing
- * all existent GPU VA mappings using this &drm_gem_object as backing buffer.
- *
- * GPU VAs can be flagged as sparse, such that drivers may use GPU VAs to also
- * keep track of sparse PTEs in order to support Vulkan 'Sparse Resources'.
- *
- * The GPU VA manager internally uses a rb-tree to manage the
- * &drm_gpuva mappings within a GPU's virtual address space.
- *
- * The &drm_gpuva_manager contains a special &drm_gpuva representing the
- * portion of VA space reserved by the kernel. This node is initialized together
- * with the GPU VA manager instance and removed when the GPU VA manager is
- * destroyed.
- *
- * In a typical application drivers would embed struct drm_gpuva_manager and
- * struct drm_gpuva within their own driver specific structures, there won't be
- * any memory allocations of its own nor memory allocations of &drm_gpuva
- * entries.
- *
- * The data structures needed to store &drm_gpuvas within the &drm_gpuva_manager
- * are contained within struct drm_gpuva already. Hence, for inserting
- * &drm_gpuva entries from within dma-fence signalling critical sections it is
- * enough to pre-allocate the &drm_gpuva structures.
- */
-
-/**
- * DOC: Split and Merge
- *
- * Besides its capability to manage and represent a GPU VA space, the
- * &drm_gpuva_manager also provides functions to let the &drm_gpuva_manager
- * calculate a sequence of operations to satisfy a given map or unmap request.
- *
- * Therefore the DRM GPU VA manager provides an algorithm implementing splitting
- * and merging of existent GPU VA mappings with the ones that are requested to
- * be mapped or unmapped. This feature is required by the Vulkan API to
- * implement Vulkan 'Sparse Memory Bindings' - drivers UAPIs often refer to this
- * as VM BIND.
- *
- * Drivers can call drm_gpuva_sm_map() to receive a sequence of callbacks
- * containing map, unmap and remap operations for a given newly requested
- * mapping. The sequence of callbacks represents the set of operations to
- * execute in order to integrate the new mapping cleanly into the current state
- * of the GPU VA space.
- *
- * Depending on how the new GPU VA mapping intersects with the existent mappings
- * of the GPU VA space the &drm_gpuva_fn_ops callbacks contain an arbitrary
- * amount of unmap operations, a maximum of two remap operations and a single
- * map operation. The caller might receive no callback at all if no operation is
- * required, e.g. if the requested mapping already exists in the exact same way.
- *
- * The single map operation represents the original map operation requested by
- * the caller.
- *
- * &drm_gpuva_op_unmap contains a 'keep' field, which indicates whether the
- * &drm_gpuva to unmap is physically contiguous with the original mapping
- * request. Optionally, if 'keep' is set, drivers may keep the actual page table
- * entries for this &drm_gpuva, adding the missing page table entries only and
- * update the &drm_gpuva_manager's view of things accordingly.
- *
- * Drivers may do the same optimization, namely delta page table updates, also
- * for remap operations. This is possible since &drm_gpuva_op_remap consists of
- * one unmap operation and one or two map operations, such that drivers can
- * derive the page table update delta accordingly.
- *
- * Note that there can't be more than two existent mappings to split up, one at
- * the beginning and one at the end of the new mapping, hence there is a
- * maximum of two remap operations.
- *
- * Analogous to drm_gpuva_sm_map() drm_gpuva_sm_unmap() uses &drm_gpuva_fn_ops
- * to call back into the driver in order to unmap a range of GPU VA space. The
- * logic behind this function is way simpler though: For all existent mappings
- * enclosed by the given range unmap operations are created. For mappings which
- * are only partically located within the given range, remap operations are
- * created such that those mappings are split up and re-mapped partically.
- *
- * As an alternative to drm_gpuva_sm_map() and drm_gpuva_sm_unmap(),
- * drm_gpuva_sm_map_ops_create() and drm_gpuva_sm_unmap_ops_create() can be used
- * to directly obtain an instance of struct drm_gpuva_ops containing a list of
- * &drm_gpuva_op, which can be iterated with drm_gpuva_for_each_op(). This list
- * contains the &drm_gpuva_ops analogous to the callbacks one would receive when
- * calling drm_gpuva_sm_map() or drm_gpuva_sm_unmap(). While this way requires
- * more memory (to allocate the &drm_gpuva_ops), it provides drivers a way to
- * iterate the &drm_gpuva_op multiple times, e.g. once in a context where memory
- * allocations are possible (e.g. to allocate GPU page tables) and once in the
- * dma-fence signalling critical path.
- *
- * To update the &drm_gpuva_manager's view of the GPU VA space
- * drm_gpuva_insert() and drm_gpuva_remove() may be used. These functions can
- * safely be used from &drm_gpuva_fn_ops callbacks originating from
- * drm_gpuva_sm_map() or drm_gpuva_sm_unmap(). However, it might be more
- * convenient to use the provided helper functions drm_gpuva_map(),
- * drm_gpuva_remap() and drm_gpuva_unmap() instead.
- *
- * The following diagram depicts the basic relationships of existent GPU VA
- * mappings, a newly requested mapping and the resulting mappings as implemented
- * by drm_gpuva_sm_map() - it doesn't cover any arbitrary combinations of these.
- *
- * 1) Requested mapping is identical. Replace it, but indicate the backing PTEs
- *    could be kept.
- *
- *    ::
- *
- *	     0     a     1
- *	old: |-----------| (bo_offset=n)
- *
- *	     0     a     1
- *	req: |-----------| (bo_offset=n)
- *
- *	     0     a     1
- *	new: |-----------| (bo_offset=n)
- *
- *
- * 2) Requested mapping is identical, except for the BO offset, hence replace
- *    the mapping.
- *
- *    ::
- *
- *	     0     a     1
- *	old: |-----------| (bo_offset=n)
- *
- *	     0     a     1
- *	req: |-----------| (bo_offset=m)
- *
- *	     0     a     1
- *	new: |-----------| (bo_offset=m)
- *
- *
- * 3) Requested mapping is identical, except for the backing BO, hence replace
- *    the mapping.
- *
- *    ::
- *
- *	     0     a     1
- *	old: |-----------| (bo_offset=n)
- *
- *	     0     b     1
- *	req: |-----------| (bo_offset=n)
- *
- *	     0     b     1
- *	new: |-----------| (bo_offset=n)
- *
- *
- * 4) Existent mapping is a left aligned subset of the requested one, hence
- *    replace the existent one.
- *
- *    ::
- *
- *	     0  a  1
- *	old: |-----|       (bo_offset=n)
- *
- *	     0     a     2
- *	req: |-----------| (bo_offset=n)
- *
- *	     0     a     2
- *	new: |-----------| (bo_offset=n)
- *
- *    .. note::
- *       We expect to see the same result for a request with a different BO
- *       and/or non-contiguous BO offset.
- *
- *
- * 5) Requested mapping's range is a left aligned subset of the existent one,
- *    but backed by a different BO. Hence, map the requested mapping and split
- *    the existent one adjusting its BO offset.
- *
- *    ::
- *
- *	     0     a     2
- *	old: |-----------| (bo_offset=n)
- *
- *	     0  b  1
- *	req: |-----|       (bo_offset=n)
- *
- *	     0  b  1  a' 2
- *	new: |-----|-----| (b.bo_offset=n, a.bo_offset=n+1)
- *
- *    .. note::
- *       We expect to see the same result for a request with a different BO
- *       and/or non-contiguous BO offset.
- *
- *
- * 6) Existent mapping is a superset of the requested mapping. Split it up, but
- *    indicate that the backing PTEs could be kept.
- *
- *    ::
- *
- *	     0     a     2
- *	old: |-----------| (bo_offset=n)
- *
- *	     0  a  1
- *	req: |-----|       (bo_offset=n)
- *
- *	     0  a  1  a' 2
- *	new: |-----|-----| (a.bo_offset=n, a'.bo_offset=n+1)
- *
- *
- * 7) Requested mapping's range is a right aligned subset of the existent one,
- *    but backed by a different BO. Hence, map the requested mapping and split
- *    the existent one, without adjusting the BO offset.
- *
- *    ::
- *
- *	     0     a     2
- *	old: |-----------| (bo_offset=n)
- *
- *	           1  b  2
- *	req:       |-----| (bo_offset=m)
- *
- *	     0  a  1  b  2
- *	new: |-----|-----| (a.bo_offset=n,b.bo_offset=m)
- *
- *
- * 8) Existent mapping is a superset of the requested mapping. Split it up, but
- *    indicate that the backing PTEs could be kept.
- *
- *    ::
- *
- *	      0     a     2
- *	old: |-----------| (bo_offset=n)
- *
- *	           1  a  2
- *	req:       |-----| (bo_offset=n+1)
- *
- *	     0  a' 1  a  2
- *	new: |-----|-----| (a'.bo_offset=n, a.bo_offset=n+1)
- *
- *
- * 9) Existent mapping is overlapped at the end by the requested mapping backed
- *    by a different BO. Hence, map the requested mapping and split up the
- *    existent one, without adjusting the BO offset.
- *
- *    ::
- *
- *	     0     a     2
- *	old: |-----------|       (bo_offset=n)
- *
- *	           1     b     3
- *	req:       |-----------| (bo_offset=m)
- *
- *	     0  a  1     b     3
- *	new: |-----|-----------| (a.bo_offset=n,b.bo_offset=m)
- *
- *
- * 10) Existent mapping is overlapped by the requested mapping, both having the
- *     same backing BO with a contiguous offset. Indicate the backing PTEs of
- *     the old mapping could be kept.
- *
- *     ::
- *
- *	      0     a     2
- *	 old: |-----------|       (bo_offset=n)
- *
- *	            1     a     3
- *	 req:       |-----------| (bo_offset=n+1)
- *
- *	      0  a' 1     a     3
- *	 new: |-----|-----------| (a'.bo_offset=n, a.bo_offset=n+1)
- *
- *
- * 11) Requested mapping's range is a centered subset of the existent one
- *     having a different backing BO. Hence, map the requested mapping and split
- *     up the existent one in two mappings, adjusting the BO offset of the right
- *     one accordingly.
- *
- *     ::
- *
- *	      0        a        3
- *	 old: |-----------------| (bo_offset=n)
- *
- *	            1  b  2
- *	 req:       |-----|       (bo_offset=m)
- *
- *	      0  a  1  b  2  a' 3
- *	 new: |-----|-----|-----| (a.bo_offset=n,b.bo_offset=m,a'.bo_offset=n+2)
- *
- *
- * 12) Requested mapping is a contiguous subset of the existent one. Split it
- *     up, but indicate that the backing PTEs could be kept.
- *
- *     ::
- *
- *	      0        a        3
- *	 old: |-----------------| (bo_offset=n)
- *
- *	            1  a  2
- *	 req:       |-----|       (bo_offset=n+1)
- *
- *	      0  a' 1  a  2 a'' 3
- *	 old: |-----|-----|-----| (a'.bo_offset=n, a.bo_offset=n+1, a''.bo_offset=n+2)
- *
- *
- * 13) Existent mapping is a right aligned subset of the requested one, hence
- *     replace the existent one.
- *
- *     ::
- *
- *	            1  a  2
- *	 old:       |-----| (bo_offset=n+1)
- *
- *	      0     a     2
- *	 req: |-----------| (bo_offset=n)
- *
- *	      0     a     2
- *	 new: |-----------| (bo_offset=n)
- *
- *     .. note::
- *        We expect to see the same result for a request with a different bo
- *        and/or non-contiguous bo_offset.
- *
- *
- * 14) Existent mapping is a centered subset of the requested one, hence
- *     replace the existent one.
- *
- *     ::
- *
- *	            1  a  2
- *	 old:       |-----| (bo_offset=n+1)
- *
- *	      0        a       3
- *	 req: |----------------| (bo_offset=n)
- *
- *	      0        a       3
- *	 new: |----------------| (bo_offset=n)
- *
- *     .. note::
- *        We expect to see the same result for a request with a different bo
- *        and/or non-contiguous bo_offset.
- *
- *
- * 15) Existent mappings is overlapped at the beginning by the requested mapping
- *     backed by a different BO. Hence, map the requested mapping and split up
- *     the existent one, adjusting its BO offset accordingly.
- *
- *     ::
- *
- *	            1     a     3
- *	 old:       |-----------| (bo_offset=n)
- *
- *	      0     b     2
- *	 req: |-----------|       (bo_offset=m)
- *
- *	      0     b     2  a' 3
- *	 new: |-----------|-----| (b.bo_offset=m,a.bo_offset=n+2)
- */
-
-/**
- * DOC: Locking
- *
- * Generally, the GPU VA manager does not take care of locking itself, it is
- * the drivers responsibility to take care about locking. Drivers might want to
- * protect the following operations: inserting, removing and iterating
- * &drm_gpuva objects as well as generating all kinds of operations, such as
- * split / merge or prefetch.
- *
- * The GPU VA manager also does not take care of the locking of the backing
- * &drm_gem_object buffers GPU VA lists by itself; drivers are responsible to
- * enforce mutual exclusion using either the GEMs dma_resv lock or alternatively
- * a driver specific external lock. For the latter see also
- * drm_gem_gpuva_set_lock().
- *
- * However, the GPU VA manager contains lockdep checks to ensure callers of its
- * API hold the corresponding lock whenever the &drm_gem_objects GPU VA list is
- * accessed by functions such as drm_gpuva_link() or drm_gpuva_unlink().
- */
-
-/**
- * DOC: Examples
- *
- * This section gives two examples on how to let the DRM GPUVA Manager generate
- * &drm_gpuva_op in order to satisfy a given map or unmap request and how to
- * make use of them.
- *
- * The below code is strictly limited to illustrate the generic usage pattern.
- * To maintain simplicitly, it doesn't make use of any abstractions for common
- * code, different (asyncronous) stages with fence signalling critical paths,
- * any other helpers or error handling in terms of freeing memory and dropping
- * previously taken locks.
- *
- * 1) Obtain a list of &drm_gpuva_op to create a new mapping::
- *
- *	// Allocates a new &drm_gpuva.
- *	struct drm_gpuva * driver_gpuva_alloc(void);
- *
- *	// Typically drivers would embedd the &drm_gpuva_manager and &drm_gpuva
- *	// structure in individual driver structures and lock the dma-resv with
- *	// drm_exec or similar helpers.
- *	int driver_mapping_create(struct drm_gpuva_manager *mgr,
- *				  u64 addr, u64 range,
- *				  struct drm_gem_object *obj, u64 offset)
- *	{
- *		struct drm_gpuva_ops *ops;
- *		struct drm_gpuva_op *op
- *
- *		driver_lock_va_space();
- *		ops = drm_gpuva_sm_map_ops_create(mgr, addr, range,
- *						  obj, offset);
- *		if (IS_ERR(ops))
- *			return PTR_ERR(ops);
- *
- *		drm_gpuva_for_each_op(op, ops) {
- *			struct drm_gpuva *va;
- *
- *			switch (op->op) {
- *			case DRM_GPUVA_OP_MAP:
- *				va = driver_gpuva_alloc();
- *				if (!va)
- *					; // unwind previous VA space updates,
- *					  // free memory and unlock
- *
- *				driver_vm_map();
- *				drm_gpuva_map(mgr, va, &op->map);
- *				drm_gpuva_link(va);
- *
- *				break;
- *			case DRM_GPUVA_OP_REMAP: {
- *				struct drm_gpuva *prev = NULL, *next = NULL;
- *
- *				va = op->remap.unmap->va;
- *
- *				if (op->remap.prev) {
- *					prev = driver_gpuva_alloc();
- *					if (!prev)
- *						; // unwind previous VA space
- *						  // updates, free memory and
- *						  // unlock
- *				}
- *
- *				if (op->remap.next) {
- *					next = driver_gpuva_alloc();
- *					if (!next)
- *						; // unwind previous VA space
- *						  // updates, free memory and
- *						  // unlock
- *				}
- *
- *				driver_vm_remap();
- *				drm_gpuva_remap(prev, next, &op->remap);
- *
- *				drm_gpuva_unlink(va);
- *				if (prev)
- *					drm_gpuva_link(prev);
- *				if (next)
- *					drm_gpuva_link(next);
- *
- *				break;
- *			}
- *			case DRM_GPUVA_OP_UNMAP:
- *				va = op->unmap->va;
- *
- *				driver_vm_unmap();
- *				drm_gpuva_unlink(va);
- *				drm_gpuva_unmap(&op->unmap);
- *
- *				break;
- *			default:
- *				break;
- *			}
- *		}
- *		driver_unlock_va_space();
- *
- *		return 0;
- *	}
- *
- * 2) Receive a callback for each &drm_gpuva_op to create a new mapping::
- *
- *	struct driver_context {
- *		struct drm_gpuva_manager *mgr;
- *		struct drm_gpuva *new_va;
- *		struct drm_gpuva *prev_va;
- *		struct drm_gpuva *next_va;
- *	};
- *
- *	// ops to pass to drm_gpuva_manager_init()
- *	static const struct drm_gpuva_fn_ops driver_gpuva_ops = {
- *		.sm_step_map = driver_gpuva_map,
- *		.sm_step_remap = driver_gpuva_remap,
- *		.sm_step_unmap = driver_gpuva_unmap,
- *	};
- *
- *	// Typically drivers would embedd the &drm_gpuva_manager and &drm_gpuva
- *	// structure in individual driver structures and lock the dma-resv with
- *	// drm_exec or similar helpers.
- *	int driver_mapping_create(struct drm_gpuva_manager *mgr,
- *				  u64 addr, u64 range,
- *				  struct drm_gem_object *obj, u64 offset)
- *	{
- *		struct driver_context ctx;
- *		struct drm_gpuva_ops *ops;
- *		struct drm_gpuva_op *op;
- *		int ret = 0;
- *
- *		ctx.mgr = mgr;
- *
- *		ctx.new_va = kzalloc(sizeof(*ctx.new_va), GFP_KERNEL);
- *		ctx.prev_va = kzalloc(sizeof(*ctx.prev_va), GFP_KERNEL);
- *		ctx.next_va = kzalloc(sizeof(*ctx.next_va), GFP_KERNEL);
- *		if (!ctx.new_va || !ctx.prev_va || !ctx.next_va) {
- *			ret = -ENOMEM;
- *			goto out;
- *		}
- *
- *		driver_lock_va_space();
- *		ret = drm_gpuva_sm_map(mgr, &ctx, addr, range, obj, offset);
- *		driver_unlock_va_space();
- *
- *	out:
- *		kfree(ctx.new_va);
- *		kfree(ctx.prev_va);
- *		kfree(ctx.next_va);
- *		return ret;
- *	}
- *
- *	int driver_gpuva_map(struct drm_gpuva_op *op, void *__ctx)
- *	{
- *		struct driver_context *ctx = __ctx;
- *
- *		drm_gpuva_map(ctx->mgr, ctx->new_va, &op->map);
- *
- *		drm_gpuva_link(ctx->new_va);
- *
- *		// prevent the new GPUVA from being freed in
- *		// driver_mapping_create()
- *		ctx->new_va = NULL;
- *
- *		return 0;
- *	}
- *
- *	int driver_gpuva_remap(struct drm_gpuva_op *op, void *__ctx)
- *	{
- *		struct driver_context *ctx = __ctx;
- *
- *		drm_gpuva_remap(ctx->prev_va, ctx->next_va, &op->remap);
- *
- *		drm_gpuva_unlink(op->remap.unmap->va);
- *		kfree(op->remap.unmap->va);
- *
- *		if (op->remap.prev) {
- *			drm_gpuva_link(ctx->prev_va);
- *			ctx->prev_va = NULL;
- *		}
- *
- *		if (op->remap.next) {
- *			drm_gpuva_link(ctx->next_va);
- *			ctx->next_va = NULL;
- *		}
- *
- *		return 0;
- *	}
- *
- *	int driver_gpuva_unmap(struct drm_gpuva_op *op, void *__ctx)
- *	{
- *		drm_gpuva_unlink(op->unmap.va);
- *		drm_gpuva_unmap(&op->unmap);
- *		kfree(op->unmap.va);
- *
- *		return 0;
- *	}
- */
-
-#define to_drm_gpuva(__node)	container_of((__node), struct drm_gpuva, rb.node)
-
-#define GPUVA_START(node) ((node)->va.addr)
-#define GPUVA_LAST(node) ((node)->va.addr + (node)->va.range - 1)
-
-/* We do not actually use drm_gpuva_it_next(), tell the compiler to not complain
- * about this.
- */
-INTERVAL_TREE_DEFINE(struct drm_gpuva, rb.node, u64, rb.__subtree_last,
-		     GPUVA_START, GPUVA_LAST, static __maybe_unused,
-		     drm_gpuva_it)
-
-static int __drm_gpuva_insert(struct drm_gpuva_manager *mgr,
-			      struct drm_gpuva *va);
-static void __drm_gpuva_remove(struct drm_gpuva *va);
-
-static bool
-drm_gpuva_check_overflow(u64 addr, u64 range)
-{
-	u64 end;
-
-	return WARN(check_add_overflow(addr, range, &end),
-		    "GPUVA address limited to %zu bytes.\n", sizeof(end));
-}
-
-static bool
-drm_gpuva_in_mm_range(struct drm_gpuva_manager *mgr, u64 addr, u64 range)
-{
-	u64 end = addr + range;
-	u64 mm_start = mgr->mm_start;
-	u64 mm_end = mm_start + mgr->mm_range;
-
-	return addr >= mm_start && end <= mm_end;
-}
-
-static bool
-drm_gpuva_in_kernel_node(struct drm_gpuva_manager *mgr, u64 addr, u64 range)
-{
-	u64 end = addr + range;
-	u64 kstart = mgr->kernel_alloc_node.va.addr;
-	u64 krange = mgr->kernel_alloc_node.va.range;
-	u64 kend = kstart + krange;
-
-	return krange && addr < kend && kstart < end;
-}
-
-static bool
-drm_gpuva_range_valid(struct drm_gpuva_manager *mgr,
-		      u64 addr, u64 range)
-{
-	return !drm_gpuva_check_overflow(addr, range) &&
-	       drm_gpuva_in_mm_range(mgr, addr, range) &&
-	       !drm_gpuva_in_kernel_node(mgr, addr, range);
-}
-
-/**
- * drm_gpuva_manager_init() - initialize a &drm_gpuva_manager
- * @mgr: pointer to the &drm_gpuva_manager to initialize
- * @name: the name of the GPU VA space
- * @start_offset: the start offset of the GPU VA space
- * @range: the size of the GPU VA space
- * @reserve_offset: the start of the kernel reserved GPU VA area
- * @reserve_range: the size of the kernel reserved GPU VA area
- * @ops: &drm_gpuva_fn_ops called on &drm_gpuva_sm_map / &drm_gpuva_sm_unmap
- *
- * The &drm_gpuva_manager must be initialized with this function before use.
- *
- * Note that @mgr must be cleared to 0 before calling this function. The given
- * &name is expected to be managed by the surrounding driver structures.
- */
-void
-drm_gpuva_manager_init(struct drm_gpuva_manager *mgr,
-		       const char *name,
-		       u64 start_offset, u64 range,
-		       u64 reserve_offset, u64 reserve_range,
-		       const struct drm_gpuva_fn_ops *ops)
-{
-	mgr->rb.tree = RB_ROOT_CACHED;
-	INIT_LIST_HEAD(&mgr->rb.list);
-
-	drm_gpuva_check_overflow(start_offset, range);
-	mgr->mm_start = start_offset;
-	mgr->mm_range = range;
-
-	mgr->name = name ? name : "unknown";
-	mgr->ops = ops;
-
-	memset(&mgr->kernel_alloc_node, 0, sizeof(struct drm_gpuva));
-
-	if (reserve_range) {
-		mgr->kernel_alloc_node.va.addr = reserve_offset;
-		mgr->kernel_alloc_node.va.range = reserve_range;
-
-		if (likely(!drm_gpuva_check_overflow(reserve_offset,
-						     reserve_range)))
-			__drm_gpuva_insert(mgr, &mgr->kernel_alloc_node);
-	}
-}
-EXPORT_SYMBOL_GPL(drm_gpuva_manager_init);
-
-/**
- * drm_gpuva_manager_destroy() - cleanup a &drm_gpuva_manager
- * @mgr: pointer to the &drm_gpuva_manager to clean up
- *
- * Note that it is a bug to call this function on a manager that still
- * holds GPU VA mappings.
- */
-void
-drm_gpuva_manager_destroy(struct drm_gpuva_manager *mgr)
-{
-	mgr->name = NULL;
-
-	if (mgr->kernel_alloc_node.va.range)
-		__drm_gpuva_remove(&mgr->kernel_alloc_node);
-
-	WARN(!RB_EMPTY_ROOT(&mgr->rb.tree.rb_root),
-	     "GPUVA tree is not empty, potentially leaking memory.");
-}
-EXPORT_SYMBOL_GPL(drm_gpuva_manager_destroy);
-
-static int
-__drm_gpuva_insert(struct drm_gpuva_manager *mgr,
-		   struct drm_gpuva *va)
-{
-	struct rb_node *node;
-	struct list_head *head;
-
-	if (drm_gpuva_it_iter_first(&mgr->rb.tree,
-				    GPUVA_START(va),
-				    GPUVA_LAST(va)))
-		return -EEXIST;
-
-	va->mgr = mgr;
-
-	drm_gpuva_it_insert(va, &mgr->rb.tree);
-
-	node = rb_prev(&va->rb.node);
-	if (node)
-		head = &(to_drm_gpuva(node))->rb.entry;
-	else
-		head = &mgr->rb.list;
-
-	list_add(&va->rb.entry, head);
-
-	return 0;
-}
-
-/**
- * drm_gpuva_insert() - insert a &drm_gpuva
- * @mgr: the &drm_gpuva_manager to insert the &drm_gpuva in
- * @va: the &drm_gpuva to insert
- *
- * Insert a &drm_gpuva with a given address and range into a
- * &drm_gpuva_manager.
- *
- * It is safe to use this function using the safe versions of iterating the GPU
- * VA space, such as drm_gpuva_for_each_va_safe() and
- * drm_gpuva_for_each_va_range_safe().
- *
- * Returns: 0 on success, negative error code on failure.
- */
-int
-drm_gpuva_insert(struct drm_gpuva_manager *mgr,
-		 struct drm_gpuva *va)
-{
-	u64 addr = va->va.addr;
-	u64 range = va->va.range;
-
-	if (unlikely(!drm_gpuva_range_valid(mgr, addr, range)))
-		return -EINVAL;
-
-	return __drm_gpuva_insert(mgr, va);
-}
-EXPORT_SYMBOL_GPL(drm_gpuva_insert);
-
-static void
-__drm_gpuva_remove(struct drm_gpuva *va)
-{
-	drm_gpuva_it_remove(va, &va->mgr->rb.tree);
-	list_del_init(&va->rb.entry);
-}
-
-/**
- * drm_gpuva_remove() - remove a &drm_gpuva
- * @va: the &drm_gpuva to remove
- *
- * This removes the given &va from the underlaying tree.
- *
- * It is safe to use this function using the safe versions of iterating the GPU
- * VA space, such as drm_gpuva_for_each_va_safe() and
- * drm_gpuva_for_each_va_range_safe().
- */
-void
-drm_gpuva_remove(struct drm_gpuva *va)
-{
-	struct drm_gpuva_manager *mgr = va->mgr;
-
-	if (unlikely(va == &mgr->kernel_alloc_node)) {
-		WARN(1, "Can't destroy kernel reserved node.\n");
-		return;
-	}
-
-	__drm_gpuva_remove(va);
-}
-EXPORT_SYMBOL_GPL(drm_gpuva_remove);
-
-/**
- * drm_gpuva_link() - link a &drm_gpuva
- * @va: the &drm_gpuva to link
- *
- * This adds the given &va to the GPU VA list of the &drm_gem_object it is
- * associated with.
- *
- * This function expects the caller to protect the GEM's GPUVA list against
- * concurrent access using the GEMs dma_resv lock.
- */
-void
-drm_gpuva_link(struct drm_gpuva *va)
-{
-	struct drm_gem_object *obj = va->gem.obj;
-
-	if (unlikely(!obj))
-		return;
-
-	drm_gem_gpuva_assert_lock_held(obj);
-
-	list_add_tail(&va->gem.entry, &obj->gpuva.list);
-}
-EXPORT_SYMBOL_GPL(drm_gpuva_link);
-
-/**
- * drm_gpuva_unlink() - unlink a &drm_gpuva
- * @va: the &drm_gpuva to unlink
- *
- * This removes the given &va from the GPU VA list of the &drm_gem_object it is
- * associated with.
- *
- * This function expects the caller to protect the GEM's GPUVA list against
- * concurrent access using the GEMs dma_resv lock.
- */
-void
-drm_gpuva_unlink(struct drm_gpuva *va)
-{
-	struct drm_gem_object *obj = va->gem.obj;
-
-	if (unlikely(!obj))
-		return;
-
-	drm_gem_gpuva_assert_lock_held(obj);
-
-	list_del_init(&va->gem.entry);
-}
-EXPORT_SYMBOL_GPL(drm_gpuva_unlink);
-
-/**
- * drm_gpuva_find_first() - find the first &drm_gpuva in the given range
- * @mgr: the &drm_gpuva_manager to search in
- * @addr: the &drm_gpuvas address
- * @range: the &drm_gpuvas range
- *
- * Returns: the first &drm_gpuva within the given range
- */
-struct drm_gpuva *
-drm_gpuva_find_first(struct drm_gpuva_manager *mgr,
-		     u64 addr, u64 range)
-{
-	u64 last = addr + range - 1;
-
-	return drm_gpuva_it_iter_first(&mgr->rb.tree, addr, last);
-}
-EXPORT_SYMBOL_GPL(drm_gpuva_find_first);
-
-/**
- * drm_gpuva_find() - find a &drm_gpuva
- * @mgr: the &drm_gpuva_manager to search in
- * @addr: the &drm_gpuvas address
- * @range: the &drm_gpuvas range
- *
- * Returns: the &drm_gpuva at a given &addr and with a given &range
- */
-struct drm_gpuva *
-drm_gpuva_find(struct drm_gpuva_manager *mgr,
-	       u64 addr, u64 range)
-{
-	struct drm_gpuva *va;
-
-	va = drm_gpuva_find_first(mgr, addr, range);
-	if (!va)
-		goto out;
-
-	if (va->va.addr != addr ||
-	    va->va.range != range)
-		goto out;
-
-	return va;
-
-out:
-	return NULL;
-}
-EXPORT_SYMBOL_GPL(drm_gpuva_find);
-
-/**
- * drm_gpuva_find_prev() - find the &drm_gpuva before the given address
- * @mgr: the &drm_gpuva_manager to search in
- * @start: the given GPU VA's start address
- *
- * Find the adjacent &drm_gpuva before the GPU VA with given &start address.
- *
- * Note that if there is any free space between the GPU VA mappings no mapping
- * is returned.
- *
- * Returns: a pointer to the found &drm_gpuva or NULL if none was found
- */
-struct drm_gpuva *
-drm_gpuva_find_prev(struct drm_gpuva_manager *mgr, u64 start)
-{
-	if (!drm_gpuva_range_valid(mgr, start - 1, 1))
-		return NULL;
-
-	return drm_gpuva_it_iter_first(&mgr->rb.tree, start - 1, start);
-}
-EXPORT_SYMBOL_GPL(drm_gpuva_find_prev);
-
-/**
- * drm_gpuva_find_next() - find the &drm_gpuva after the given address
- * @mgr: the &drm_gpuva_manager to search in
- * @end: the given GPU VA's end address
- *
- * Find the adjacent &drm_gpuva after the GPU VA with given &end address.
- *
- * Note that if there is any free space between the GPU VA mappings no mapping
- * is returned.
- *
- * Returns: a pointer to the found &drm_gpuva or NULL if none was found
- */
-struct drm_gpuva *
-drm_gpuva_find_next(struct drm_gpuva_manager *mgr, u64 end)
-{
-	if (!drm_gpuva_range_valid(mgr, end, 1))
-		return NULL;
-
-	return drm_gpuva_it_iter_first(&mgr->rb.tree, end, end + 1);
-}
-EXPORT_SYMBOL_GPL(drm_gpuva_find_next);
-
-/**
- * drm_gpuva_interval_empty() - indicate whether a given interval of the VA space
- * is empty
- * @mgr: the &drm_gpuva_manager to check the range for
- * @addr: the start address of the range
- * @range: the range of the interval
- *
- * Returns: true if the interval is empty, false otherwise
- */
-bool
-drm_gpuva_interval_empty(struct drm_gpuva_manager *mgr, u64 addr, u64 range)
-{
-	return !drm_gpuva_find_first(mgr, addr, range);
-}
-EXPORT_SYMBOL_GPL(drm_gpuva_interval_empty);
-
-/**
- * drm_gpuva_map() - helper to insert a &drm_gpuva according to a
- * &drm_gpuva_op_map
- * @mgr: the &drm_gpuva_manager
- * @va: the &drm_gpuva to insert
- * @op: the &drm_gpuva_op_map to initialize @va with
- *
- * Initializes the @va from the @op and inserts it into the given @mgr.
- */
-void
-drm_gpuva_map(struct drm_gpuva_manager *mgr,
-	      struct drm_gpuva *va,
-	      struct drm_gpuva_op_map *op)
-{
-	drm_gpuva_init_from_op(va, op);
-	drm_gpuva_insert(mgr, va);
-}
-EXPORT_SYMBOL_GPL(drm_gpuva_map);
-
-/**
- * drm_gpuva_remap() - helper to remap a &drm_gpuva according to a
- * &drm_gpuva_op_remap
- * @prev: the &drm_gpuva to remap when keeping the start of a mapping
- * @next: the &drm_gpuva to remap when keeping the end of a mapping
- * @op: the &drm_gpuva_op_remap to initialize @prev and @next with
- *
- * Removes the currently mapped &drm_gpuva and remaps it using @prev and/or
- * @next.
- */
-void
-drm_gpuva_remap(struct drm_gpuva *prev,
-		struct drm_gpuva *next,
-		struct drm_gpuva_op_remap *op)
-{
-	struct drm_gpuva *curr = op->unmap->va;
-	struct drm_gpuva_manager *mgr = curr->mgr;
-
-	drm_gpuva_remove(curr);
-
-	if (op->prev) {
-		drm_gpuva_init_from_op(prev, op->prev);
-		drm_gpuva_insert(mgr, prev);
-	}
-
-	if (op->next) {
-		drm_gpuva_init_from_op(next, op->next);
-		drm_gpuva_insert(mgr, next);
-	}
-}
-EXPORT_SYMBOL_GPL(drm_gpuva_remap);
-
-/**
- * drm_gpuva_unmap() - helper to remove a &drm_gpuva according to a
- * &drm_gpuva_op_unmap
- * @op: the &drm_gpuva_op_unmap specifying the &drm_gpuva to remove
- *
- * Removes the &drm_gpuva associated with the &drm_gpuva_op_unmap.
- */
-void
-drm_gpuva_unmap(struct drm_gpuva_op_unmap *op)
-{
-	drm_gpuva_remove(op->va);
-}
-EXPORT_SYMBOL_GPL(drm_gpuva_unmap);
-
-static int
-op_map_cb(const struct drm_gpuva_fn_ops *fn, void *priv,
-	  u64 addr, u64 range,
-	  struct drm_gem_object *obj, u64 offset)
-{
-	struct drm_gpuva_op op = {};
-
-	op.op = DRM_GPUVA_OP_MAP;
-	op.map.va.addr = addr;
-	op.map.va.range = range;
-	op.map.gem.obj = obj;
-	op.map.gem.offset = offset;
-
-	return fn->sm_step_map(&op, priv);
-}
-
-static int
-op_remap_cb(const struct drm_gpuva_fn_ops *fn, void *priv,
-	    struct drm_gpuva_op_map *prev,
-	    struct drm_gpuva_op_map *next,
-	    struct drm_gpuva_op_unmap *unmap)
-{
-	struct drm_gpuva_op op = {};
-	struct drm_gpuva_op_remap *r;
-
-	op.op = DRM_GPUVA_OP_REMAP;
-	r = &op.remap;
-	r->prev = prev;
-	r->next = next;
-	r->unmap = unmap;
-
-	return fn->sm_step_remap(&op, priv);
-}
-
-static int
-op_unmap_cb(const struct drm_gpuva_fn_ops *fn, void *priv,
-	    struct drm_gpuva *va, bool merge)
-{
-	struct drm_gpuva_op op = {};
-
-	op.op = DRM_GPUVA_OP_UNMAP;
-	op.unmap.va = va;
-	op.unmap.keep = merge;
-
-	return fn->sm_step_unmap(&op, priv);
-}
-
-static int
-__drm_gpuva_sm_map(struct drm_gpuva_manager *mgr,
-		   const struct drm_gpuva_fn_ops *ops, void *priv,
-		   u64 req_addr, u64 req_range,
-		   struct drm_gem_object *req_obj, u64 req_offset)
-{
-	struct drm_gpuva *va, *next;
-	u64 req_end = req_addr + req_range;
-	int ret;
-
-	if (unlikely(!drm_gpuva_range_valid(mgr, req_addr, req_range)))
-		return -EINVAL;
-
-	drm_gpuva_for_each_va_range_safe(va, next, mgr, req_addr, req_end) {
-		struct drm_gem_object *obj = va->gem.obj;
-		u64 offset = va->gem.offset;
-		u64 addr = va->va.addr;
-		u64 range = va->va.range;
-		u64 end = addr + range;
-		bool merge = !!va->gem.obj;
-
-		if (addr == req_addr) {
-			merge &= obj == req_obj &&
-				 offset == req_offset;
-
-			if (end == req_end) {
-				ret = op_unmap_cb(ops, priv, va, merge);
-				if (ret)
-					return ret;
-				break;
-			}
-
-			if (end < req_end) {
-				ret = op_unmap_cb(ops, priv, va, merge);
-				if (ret)
-					return ret;
-				continue;
-			}
-
-			if (end > req_end) {
-				struct drm_gpuva_op_map n = {
-					.va.addr = req_end,
-					.va.range = range - req_range,
-					.gem.obj = obj,
-					.gem.offset = offset + req_range,
-				};
-				struct drm_gpuva_op_unmap u = {
-					.va = va,
-					.keep = merge,
-				};
-
-				ret = op_remap_cb(ops, priv, NULL, &n, &u);
-				if (ret)
-					return ret;
-				break;
-			}
-		} else if (addr < req_addr) {
-			u64 ls_range = req_addr - addr;
-			struct drm_gpuva_op_map p = {
-				.va.addr = addr,
-				.va.range = ls_range,
-				.gem.obj = obj,
-				.gem.offset = offset,
-			};
-			struct drm_gpuva_op_unmap u = { .va = va };
-
-			merge &= obj == req_obj &&
-				 offset + ls_range == req_offset;
-			u.keep = merge;
-
-			if (end == req_end) {
-				ret = op_remap_cb(ops, priv, &p, NULL, &u);
-				if (ret)
-					return ret;
-				break;
-			}
-
-			if (end < req_end) {
-				ret = op_remap_cb(ops, priv, &p, NULL, &u);
-				if (ret)
-					return ret;
-				continue;
-			}
-
-			if (end > req_end) {
-				struct drm_gpuva_op_map n = {
-					.va.addr = req_end,
-					.va.range = end - req_end,
-					.gem.obj = obj,
-					.gem.offset = offset + ls_range +
-						      req_range,
-				};
-
-				ret = op_remap_cb(ops, priv, &p, &n, &u);
-				if (ret)
-					return ret;
-				break;
-			}
-		} else if (addr > req_addr) {
-			merge &= obj == req_obj &&
-				 offset == req_offset +
-					   (addr - req_addr);
-
-			if (end == req_end) {
-				ret = op_unmap_cb(ops, priv, va, merge);
-				if (ret)
-					return ret;
-				break;
-			}
-
-			if (end < req_end) {
-				ret = op_unmap_cb(ops, priv, va, merge);
-				if (ret)
-					return ret;
-				continue;
-			}
-
-			if (end > req_end) {
-				struct drm_gpuva_op_map n = {
-					.va.addr = req_end,
-					.va.range = end - req_end,
-					.gem.obj = obj,
-					.gem.offset = offset + req_end - addr,
-				};
-				struct drm_gpuva_op_unmap u = {
-					.va = va,
-					.keep = merge,
-				};
-
-				ret = op_remap_cb(ops, priv, NULL, &n, &u);
-				if (ret)
-					return ret;
-				break;
-			}
-		}
-	}
-
-	return op_map_cb(ops, priv,
-			 req_addr, req_range,
-			 req_obj, req_offset);
-}
-
-static int
-__drm_gpuva_sm_unmap(struct drm_gpuva_manager *mgr,
-		     const struct drm_gpuva_fn_ops *ops, void *priv,
-		     u64 req_addr, u64 req_range)
-{
-	struct drm_gpuva *va, *next;
-	u64 req_end = req_addr + req_range;
-	int ret;
-
-	if (unlikely(!drm_gpuva_range_valid(mgr, req_addr, req_range)))
-		return -EINVAL;
-
-	drm_gpuva_for_each_va_range_safe(va, next, mgr, req_addr, req_end) {
-		struct drm_gpuva_op_map prev = {}, next = {};
-		bool prev_split = false, next_split = false;
-		struct drm_gem_object *obj = va->gem.obj;
-		u64 offset = va->gem.offset;
-		u64 addr = va->va.addr;
-		u64 range = va->va.range;
-		u64 end = addr + range;
-
-		if (addr < req_addr) {
-			prev.va.addr = addr;
-			prev.va.range = req_addr - addr;
-			prev.gem.obj = obj;
-			prev.gem.offset = offset;
-
-			prev_split = true;
-		}
-
-		if (end > req_end) {
-			next.va.addr = req_end;
-			next.va.range = end - req_end;
-			next.gem.obj = obj;
-			next.gem.offset = offset + (req_end - addr);
-
-			next_split = true;
-		}
-
-		if (prev_split || next_split) {
-			struct drm_gpuva_op_unmap unmap = { .va = va };
-
-			ret = op_remap_cb(ops, priv,
-					  prev_split ? &prev : NULL,
-					  next_split ? &next : NULL,
-					  &unmap);
-			if (ret)
-				return ret;
-		} else {
-			ret = op_unmap_cb(ops, priv, va, false);
-			if (ret)
-				return ret;
-		}
-	}
-
-	return 0;
-}
-
-/**
- * drm_gpuva_sm_map() - creates the &drm_gpuva_op split/merge steps
- * @mgr: the &drm_gpuva_manager representing the GPU VA space
- * @req_addr: the start address of the new mapping
- * @req_range: the range of the new mapping
- * @req_obj: the &drm_gem_object to map
- * @req_offset: the offset within the &drm_gem_object
- * @priv: pointer to a driver private data structure
- *
- * This function iterates the given range of the GPU VA space. It utilizes the
- * &drm_gpuva_fn_ops to call back into the driver providing the split and merge
- * steps.
- *
- * Drivers may use these callbacks to update the GPU VA space right away within
- * the callback. In case the driver decides to copy and store the operations for
- * later processing neither this function nor &drm_gpuva_sm_unmap is allowed to
- * be called before the &drm_gpuva_manager's view of the GPU VA space was
- * updated with the previous set of operations. To update the
- * &drm_gpuva_manager's view of the GPU VA space drm_gpuva_insert(),
- * drm_gpuva_destroy_locked() and/or drm_gpuva_destroy_unlocked() should be
- * used.
- *
- * A sequence of callbacks can contain map, unmap and remap operations, but
- * the sequence of callbacks might also be empty if no operation is required,
- * e.g. if the requested mapping already exists in the exact same way.
- *
- * There can be an arbitrary amount of unmap operations, a maximum of two remap
- * operations and a single map operation. The latter one represents the original
- * map operation requested by the caller.
- *
- * Returns: 0 on success or a negative error code
- */
-int
-drm_gpuva_sm_map(struct drm_gpuva_manager *mgr, void *priv,
-		 u64 req_addr, u64 req_range,
-		 struct drm_gem_object *req_obj, u64 req_offset)
-{
-	const struct drm_gpuva_fn_ops *ops = mgr->ops;
-
-	if (unlikely(!(ops && ops->sm_step_map &&
-		       ops->sm_step_remap &&
-		       ops->sm_step_unmap)))
-		return -EINVAL;
-
-	return __drm_gpuva_sm_map(mgr, ops, priv,
-				  req_addr, req_range,
-				  req_obj, req_offset);
-}
-EXPORT_SYMBOL_GPL(drm_gpuva_sm_map);
-
-/**
- * drm_gpuva_sm_unmap() - creates the &drm_gpuva_ops to split on unmap
- * @mgr: the &drm_gpuva_manager representing the GPU VA space
- * @priv: pointer to a driver private data structure
- * @req_addr: the start address of the range to unmap
- * @req_range: the range of the mappings to unmap
- *
- * This function iterates the given range of the GPU VA space. It utilizes the
- * &drm_gpuva_fn_ops to call back into the driver providing the operations to
- * unmap and, if required, split existent mappings.
- *
- * Drivers may use these callbacks to update the GPU VA space right away within
- * the callback. In case the driver decides to copy and store the operations for
- * later processing neither this function nor &drm_gpuva_sm_map is allowed to be
- * called before the &drm_gpuva_manager's view of the GPU VA space was updated
- * with the previous set of operations. To update the &drm_gpuva_manager's view
- * of the GPU VA space drm_gpuva_insert(), drm_gpuva_destroy_locked() and/or
- * drm_gpuva_destroy_unlocked() should be used.
- *
- * A sequence of callbacks can contain unmap and remap operations, depending on
- * whether there are actual overlapping mappings to split.
- *
- * There can be an arbitrary amount of unmap operations and a maximum of two
- * remap operations.
- *
- * Returns: 0 on success or a negative error code
- */
-int
-drm_gpuva_sm_unmap(struct drm_gpuva_manager *mgr, void *priv,
-		   u64 req_addr, u64 req_range)
-{
-	const struct drm_gpuva_fn_ops *ops = mgr->ops;
-
-	if (unlikely(!(ops && ops->sm_step_remap &&
-		       ops->sm_step_unmap)))
-		return -EINVAL;
-
-	return __drm_gpuva_sm_unmap(mgr, ops, priv,
-				    req_addr, req_range);
-}
-EXPORT_SYMBOL_GPL(drm_gpuva_sm_unmap);
-
-static struct drm_gpuva_op *
-gpuva_op_alloc(struct drm_gpuva_manager *mgr)
-{
-	const struct drm_gpuva_fn_ops *fn = mgr->ops;
-	struct drm_gpuva_op *op;
-
-	if (fn && fn->op_alloc)
-		op = fn->op_alloc();
-	else
-		op = kzalloc(sizeof(*op), GFP_KERNEL);
-
-	if (unlikely(!op))
-		return NULL;
-
-	return op;
-}
-
-static void
-gpuva_op_free(struct drm_gpuva_manager *mgr,
-	      struct drm_gpuva_op *op)
-{
-	const struct drm_gpuva_fn_ops *fn = mgr->ops;
-
-	if (fn && fn->op_free)
-		fn->op_free(op);
-	else
-		kfree(op);
-}
-
-static int
-drm_gpuva_sm_step(struct drm_gpuva_op *__op,
-		  void *priv)
-{
-	struct {
-		struct drm_gpuva_manager *mgr;
-		struct drm_gpuva_ops *ops;
-	} *args = priv;
-	struct drm_gpuva_manager *mgr = args->mgr;
-	struct drm_gpuva_ops *ops = args->ops;
-	struct drm_gpuva_op *op;
-
-	op = gpuva_op_alloc(mgr);
-	if (unlikely(!op))
-		goto err;
-
-	memcpy(op, __op, sizeof(*op));
-
-	if (op->op == DRM_GPUVA_OP_REMAP) {
-		struct drm_gpuva_op_remap *__r = &__op->remap;
-		struct drm_gpuva_op_remap *r = &op->remap;
-
-		r->unmap = kmemdup(__r->unmap, sizeof(*r->unmap),
-				   GFP_KERNEL);
-		if (unlikely(!r->unmap))
-			goto err_free_op;
-
-		if (__r->prev) {
-			r->prev = kmemdup(__r->prev, sizeof(*r->prev),
-					  GFP_KERNEL);
-			if (unlikely(!r->prev))
-				goto err_free_unmap;
-		}
-
-		if (__r->next) {
-			r->next = kmemdup(__r->next, sizeof(*r->next),
-					  GFP_KERNEL);
-			if (unlikely(!r->next))
-				goto err_free_prev;
-		}
-	}
-
-	list_add_tail(&op->entry, &ops->list);
-
-	return 0;
-
-err_free_unmap:
-	kfree(op->remap.unmap);
-err_free_prev:
-	kfree(op->remap.prev);
-err_free_op:
-	gpuva_op_free(mgr, op);
-err:
-	return -ENOMEM;
-}
-
-static const struct drm_gpuva_fn_ops gpuva_list_ops = {
-	.sm_step_map = drm_gpuva_sm_step,
-	.sm_step_remap = drm_gpuva_sm_step,
-	.sm_step_unmap = drm_gpuva_sm_step,
-};
-
-/**
- * drm_gpuva_sm_map_ops_create() - creates the &drm_gpuva_ops to split and merge
- * @mgr: the &drm_gpuva_manager representing the GPU VA space
- * @req_addr: the start address of the new mapping
- * @req_range: the range of the new mapping
- * @req_obj: the &drm_gem_object to map
- * @req_offset: the offset within the &drm_gem_object
- *
- * This function creates a list of operations to perform splitting and merging
- * of existent mapping(s) with the newly requested one.
- *
- * The list can be iterated with &drm_gpuva_for_each_op and must be processed
- * in the given order. It can contain map, unmap and remap operations, but it
- * also can be empty if no operation is required, e.g. if the requested mapping
- * already exists is the exact same way.
- *
- * There can be an arbitrary amount of unmap operations, a maximum of two remap
- * operations and a single map operation. The latter one represents the original
- * map operation requested by the caller.
- *
- * Note that before calling this function again with another mapping request it
- * is necessary to update the &drm_gpuva_manager's view of the GPU VA space. The
- * previously obtained operations must be either processed or abandoned. To
- * update the &drm_gpuva_manager's view of the GPU VA space drm_gpuva_insert(),
- * drm_gpuva_destroy_locked() and/or drm_gpuva_destroy_unlocked() should be
- * used.
- *
- * After the caller finished processing the returned &drm_gpuva_ops, they must
- * be freed with &drm_gpuva_ops_free.
- *
- * Returns: a pointer to the &drm_gpuva_ops on success, an ERR_PTR on failure
- */
-struct drm_gpuva_ops *
-drm_gpuva_sm_map_ops_create(struct drm_gpuva_manager *mgr,
-			    u64 req_addr, u64 req_range,
-			    struct drm_gem_object *req_obj, u64 req_offset)
-{
-	struct drm_gpuva_ops *ops;
-	struct {
-		struct drm_gpuva_manager *mgr;
-		struct drm_gpuva_ops *ops;
-	} args;
-	int ret;
-
-	ops = kzalloc(sizeof(*ops), GFP_KERNEL);
-	if (unlikely(!ops))
-		return ERR_PTR(-ENOMEM);
-
-	INIT_LIST_HEAD(&ops->list);
-
-	args.mgr = mgr;
-	args.ops = ops;
-
-	ret = __drm_gpuva_sm_map(mgr, &gpuva_list_ops, &args,
-				 req_addr, req_range,
-				 req_obj, req_offset);
-	if (ret)
-		goto err_free_ops;
-
-	return ops;
-
-err_free_ops:
-	drm_gpuva_ops_free(mgr, ops);
-	return ERR_PTR(ret);
-}
-EXPORT_SYMBOL_GPL(drm_gpuva_sm_map_ops_create);
-
-/**
- * drm_gpuva_sm_unmap_ops_create() - creates the &drm_gpuva_ops to split on
- * unmap
- * @mgr: the &drm_gpuva_manager representing the GPU VA space
- * @req_addr: the start address of the range to unmap
- * @req_range: the range of the mappings to unmap
- *
- * This function creates a list of operations to perform unmapping and, if
- * required, splitting of the mappings overlapping the unmap range.
- *
- * The list can be iterated with &drm_gpuva_for_each_op and must be processed
- * in the given order. It can contain unmap and remap operations, depending on
- * whether there are actual overlapping mappings to split.
- *
- * There can be an arbitrary amount of unmap operations and a maximum of two
- * remap operations.
- *
- * Note that before calling this function again with another range to unmap it
- * is necessary to update the &drm_gpuva_manager's view of the GPU VA space. The
- * previously obtained operations must be processed or abandoned. To update the
- * &drm_gpuva_manager's view of the GPU VA space drm_gpuva_insert(),
- * drm_gpuva_destroy_locked() and/or drm_gpuva_destroy_unlocked() should be
- * used.
- *
- * After the caller finished processing the returned &drm_gpuva_ops, they must
- * be freed with &drm_gpuva_ops_free.
- *
- * Returns: a pointer to the &drm_gpuva_ops on success, an ERR_PTR on failure
- */
-struct drm_gpuva_ops *
-drm_gpuva_sm_unmap_ops_create(struct drm_gpuva_manager *mgr,
-			      u64 req_addr, u64 req_range)
-{
-	struct drm_gpuva_ops *ops;
-	struct {
-		struct drm_gpuva_manager *mgr;
-		struct drm_gpuva_ops *ops;
-	} args;
-	int ret;
-
-	ops = kzalloc(sizeof(*ops), GFP_KERNEL);
-	if (unlikely(!ops))
-		return ERR_PTR(-ENOMEM);
-
-	INIT_LIST_HEAD(&ops->list);
-
-	args.mgr = mgr;
-	args.ops = ops;
-
-	ret = __drm_gpuva_sm_unmap(mgr, &gpuva_list_ops, &args,
-				   req_addr, req_range);
-	if (ret)
-		goto err_free_ops;
-
-	return ops;
-
-err_free_ops:
-	drm_gpuva_ops_free(mgr, ops);
-	return ERR_PTR(ret);
-}
-EXPORT_SYMBOL_GPL(drm_gpuva_sm_unmap_ops_create);
-
-/**
- * drm_gpuva_prefetch_ops_create() - creates the &drm_gpuva_ops to prefetch
- * @mgr: the &drm_gpuva_manager representing the GPU VA space
- * @addr: the start address of the range to prefetch
- * @range: the range of the mappings to prefetch
- *
- * This function creates a list of operations to perform prefetching.
- *
- * The list can be iterated with &drm_gpuva_for_each_op and must be processed
- * in the given order. It can contain prefetch operations.
- *
- * There can be an arbitrary amount of prefetch operations.
- *
- * After the caller finished processing the returned &drm_gpuva_ops, they must
- * be freed with &drm_gpuva_ops_free.
- *
- * Returns: a pointer to the &drm_gpuva_ops on success, an ERR_PTR on failure
- */
-struct drm_gpuva_ops *
-drm_gpuva_prefetch_ops_create(struct drm_gpuva_manager *mgr,
-			      u64 addr, u64 range)
-{
-	struct drm_gpuva_ops *ops;
-	struct drm_gpuva_op *op;
-	struct drm_gpuva *va;
-	u64 end = addr + range;
-	int ret;
-
-	ops = kzalloc(sizeof(*ops), GFP_KERNEL);
-	if (!ops)
-		return ERR_PTR(-ENOMEM);
-
-	INIT_LIST_HEAD(&ops->list);
-
-	drm_gpuva_for_each_va_range(va, mgr, addr, end) {
-		op = gpuva_op_alloc(mgr);
-		if (!op) {
-			ret = -ENOMEM;
-			goto err_free_ops;
-		}
-
-		op->op = DRM_GPUVA_OP_PREFETCH;
-		op->prefetch.va = va;
-		list_add_tail(&op->entry, &ops->list);
-	}
-
-	return ops;
-
-err_free_ops:
-	drm_gpuva_ops_free(mgr, ops);
-	return ERR_PTR(ret);
-}
-EXPORT_SYMBOL_GPL(drm_gpuva_prefetch_ops_create);
-
-/**
- * drm_gpuva_gem_unmap_ops_create() - creates the &drm_gpuva_ops to unmap a GEM
- * @mgr: the &drm_gpuva_manager representing the GPU VA space
- * @obj: the &drm_gem_object to unmap
- *
- * This function creates a list of operations to perform unmapping for every
- * GPUVA attached to a GEM.
- *
- * The list can be iterated with &drm_gpuva_for_each_op and consists out of an
- * arbitrary amount of unmap operations.
- *
- * After the caller finished processing the returned &drm_gpuva_ops, they must
- * be freed with &drm_gpuva_ops_free.
- *
- * It is the callers responsibility to protect the GEMs GPUVA list against
- * concurrent access using the GEMs dma_resv lock.
- *
- * Returns: a pointer to the &drm_gpuva_ops on success, an ERR_PTR on failure
- */
-struct drm_gpuva_ops *
-drm_gpuva_gem_unmap_ops_create(struct drm_gpuva_manager *mgr,
-			       struct drm_gem_object *obj)
-{
-	struct drm_gpuva_ops *ops;
-	struct drm_gpuva_op *op;
-	struct drm_gpuva *va;
-	int ret;
-
-	drm_gem_gpuva_assert_lock_held(obj);
-
-	ops = kzalloc(sizeof(*ops), GFP_KERNEL);
-	if (!ops)
-		return ERR_PTR(-ENOMEM);
-
-	INIT_LIST_HEAD(&ops->list);
-
-	drm_gem_for_each_gpuva(va, obj) {
-		op = gpuva_op_alloc(mgr);
-		if (!op) {
-			ret = -ENOMEM;
-			goto err_free_ops;
-		}
-
-		op->op = DRM_GPUVA_OP_UNMAP;
-		op->unmap.va = va;
-		list_add_tail(&op->entry, &ops->list);
-	}
-
-	return ops;
-
-err_free_ops:
-	drm_gpuva_ops_free(mgr, ops);
-	return ERR_PTR(ret);
-}
-EXPORT_SYMBOL_GPL(drm_gpuva_gem_unmap_ops_create);
-
-/**
- * drm_gpuva_ops_free() - free the given &drm_gpuva_ops
- * @mgr: the &drm_gpuva_manager the ops were created for
- * @ops: the &drm_gpuva_ops to free
- *
- * Frees the given &drm_gpuva_ops structure including all the ops associated
- * with it.
- */
-void
-drm_gpuva_ops_free(struct drm_gpuva_manager *mgr,
-		   struct drm_gpuva_ops *ops)
-{
-	struct drm_gpuva_op *op, *next;
-
-	drm_gpuva_for_each_op_safe(op, next, ops) {
-		list_del(&op->entry);
-
-		if (op->op == DRM_GPUVA_OP_REMAP) {
-			kfree(op->remap.prev);
-			kfree(op->remap.next);
-			kfree(op->remap.unmap);
-		}
-
-		gpuva_op_free(mgr, op);
-	}
-
-	kfree(ops);
-}
-EXPORT_SYMBOL_GPL(drm_gpuva_ops_free);
--- /dev/null
+++ b/drivers/gpu/drm/drm_gpuvm.c
@@ -0,0 +1,1723 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2022 Red Hat.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Authors:
+ *     Danilo Krummrich <dakr@redhat.com>
+ *
+ */
+
+#include <drm/drm_gpuvm.h>
+
+#include <linux/interval_tree_generic.h>
+#include <linux/mm.h>
+
+/**
+ * DOC: Overview
+ *
+ * The DRM GPU VA Manager, represented by struct drm_gpuvm keeps track of a
+ * GPU's virtual address (VA) space and manages the corresponding virtual
+ * mappings represented by &drm_gpuva objects. It also keeps track of the
+ * mapping's backing &drm_gem_object buffers.
+ *
+ * &drm_gem_object buffers maintain a list of &drm_gpuva objects representing
+ * all existent GPU VA mappings using this &drm_gem_object as backing buffer.
+ *
+ * GPU VAs can be flagged as sparse, such that drivers may use GPU VAs to also
+ * keep track of sparse PTEs in order to support Vulkan 'Sparse Resources'.
+ *
+ * The GPU VA manager internally uses a rb-tree to manage the
+ * &drm_gpuva mappings within a GPU's virtual address space.
+ *
+ * The &drm_gpuvm structure contains a special &drm_gpuva representing the
+ * portion of VA space reserved by the kernel. This node is initialized together
+ * with the GPU VA manager instance and removed when the GPU VA manager is
+ * destroyed.
+ *
+ * In a typical application drivers would embed struct drm_gpuvm and
+ * struct drm_gpuva within their own driver specific structures, there won't be
+ * any memory allocations of its own nor memory allocations of &drm_gpuva
+ * entries.
+ *
+ * The data structures needed to store &drm_gpuvas within the &drm_gpuvm are
+ * contained within struct drm_gpuva already. Hence, for inserting &drm_gpuva
+ * entries from within dma-fence signalling critical sections it is enough to
+ * pre-allocate the &drm_gpuva structures.
+ */
+
+/**
+ * DOC: Split and Merge
+ *
+ * Besides its capability to manage and represent a GPU VA space, the
+ * GPU VA manager also provides functions to let the &drm_gpuvm calculate a
+ * sequence of operations to satisfy a given map or unmap request.
+ *
+ * Therefore the DRM GPU VA manager provides an algorithm implementing splitting
+ * and merging of existent GPU VA mappings with the ones that are requested to
+ * be mapped or unmapped. This feature is required by the Vulkan API to
+ * implement Vulkan 'Sparse Memory Bindings' - drivers UAPIs often refer to this
+ * as VM BIND.
+ *
+ * Drivers can call drm_gpuvm_sm_map() to receive a sequence of callbacks
+ * containing map, unmap and remap operations for a given newly requested
+ * mapping. The sequence of callbacks represents the set of operations to
+ * execute in order to integrate the new mapping cleanly into the current state
+ * of the GPU VA space.
+ *
+ * Depending on how the new GPU VA mapping intersects with the existent mappings
+ * of the GPU VA space the &drm_gpuvm_ops callbacks contain an arbitrary amount
+ * of unmap operations, a maximum of two remap operations and a single map
+ * operation. The caller might receive no callback at all if no operation is
+ * required, e.g. if the requested mapping already exists in the exact same way.
+ *
+ * The single map operation represents the original map operation requested by
+ * the caller.
+ *
+ * &drm_gpuva_op_unmap contains a 'keep' field, which indicates whether the
+ * &drm_gpuva to unmap is physically contiguous with the original mapping
+ * request. Optionally, if 'keep' is set, drivers may keep the actual page table
+ * entries for this &drm_gpuva, adding the missing page table entries only and
+ * update the &drm_gpuvm's view of things accordingly.
+ *
+ * Drivers may do the same optimization, namely delta page table updates, also
+ * for remap operations. This is possible since &drm_gpuva_op_remap consists of
+ * one unmap operation and one or two map operations, such that drivers can
+ * derive the page table update delta accordingly.
+ *
+ * Note that there can't be more than two existent mappings to split up, one at
+ * the beginning and one at the end of the new mapping, hence there is a
+ * maximum of two remap operations.
+ *
+ * Analogous to drm_gpuvm_sm_map() drm_gpuvm_sm_unmap() uses &drm_gpuvm_ops to
+ * call back into the driver in order to unmap a range of GPU VA space. The
+ * logic behind this function is way simpler though: For all existent mappings
+ * enclosed by the given range unmap operations are created. For mappings which
+ * are only partically located within the given range, remap operations are
+ * created such that those mappings are split up and re-mapped partically.
+ *
+ * As an alternative to drm_gpuvm_sm_map() and drm_gpuvm_sm_unmap(),
+ * drm_gpuvm_sm_map_ops_create() and drm_gpuvm_sm_unmap_ops_create() can be used
+ * to directly obtain an instance of struct drm_gpuva_ops containing a list of
+ * &drm_gpuva_op, which can be iterated with drm_gpuva_for_each_op(). This list
+ * contains the &drm_gpuva_ops analogous to the callbacks one would receive when
+ * calling drm_gpuvm_sm_map() or drm_gpuvm_sm_unmap(). While this way requires
+ * more memory (to allocate the &drm_gpuva_ops), it provides drivers a way to
+ * iterate the &drm_gpuva_op multiple times, e.g. once in a context where memory
+ * allocations are possible (e.g. to allocate GPU page tables) and once in the
+ * dma-fence signalling critical path.
+ *
+ * To update the &drm_gpuvm's view of the GPU VA space drm_gpuva_insert() and
+ * drm_gpuva_remove() may be used. These functions can safely be used from
+ * &drm_gpuvm_ops callbacks originating from drm_gpuvm_sm_map() or
+ * drm_gpuvm_sm_unmap(). However, it might be more convenient to use the
+ * provided helper functions drm_gpuva_map(), drm_gpuva_remap() and
+ * drm_gpuva_unmap() instead.
+ *
+ * The following diagram depicts the basic relationships of existent GPU VA
+ * mappings, a newly requested mapping and the resulting mappings as implemented
+ * by drm_gpuvm_sm_map() - it doesn't cover any arbitrary combinations of these.
+ *
+ * 1) Requested mapping is identical. Replace it, but indicate the backing PTEs
+ *    could be kept.
+ *
+ *    ::
+ *
+ *	     0     a     1
+ *	old: |-----------| (bo_offset=n)
+ *
+ *	     0     a     1
+ *	req: |-----------| (bo_offset=n)
+ *
+ *	     0     a     1
+ *	new: |-----------| (bo_offset=n)
+ *
+ *
+ * 2) Requested mapping is identical, except for the BO offset, hence replace
+ *    the mapping.
+ *
+ *    ::
+ *
+ *	     0     a     1
+ *	old: |-----------| (bo_offset=n)
+ *
+ *	     0     a     1
+ *	req: |-----------| (bo_offset=m)
+ *
+ *	     0     a     1
+ *	new: |-----------| (bo_offset=m)
+ *
+ *
+ * 3) Requested mapping is identical, except for the backing BO, hence replace
+ *    the mapping.
+ *
+ *    ::
+ *
+ *	     0     a     1
+ *	old: |-----------| (bo_offset=n)
+ *
+ *	     0     b     1
+ *	req: |-----------| (bo_offset=n)
+ *
+ *	     0     b     1
+ *	new: |-----------| (bo_offset=n)
+ *
+ *
+ * 4) Existent mapping is a left aligned subset of the requested one, hence
+ *    replace the existent one.
+ *
+ *    ::
+ *
+ *	     0  a  1
+ *	old: |-----|       (bo_offset=n)
+ *
+ *	     0     a     2
+ *	req: |-----------| (bo_offset=n)
+ *
+ *	     0     a     2
+ *	new: |-----------| (bo_offset=n)
+ *
+ *    .. note::
+ *       We expect to see the same result for a request with a different BO
+ *       and/or non-contiguous BO offset.
+ *
+ *
+ * 5) Requested mapping's range is a left aligned subset of the existent one,
+ *    but backed by a different BO. Hence, map the requested mapping and split
+ *    the existent one adjusting its BO offset.
+ *
+ *    ::
+ *
+ *	     0     a     2
+ *	old: |-----------| (bo_offset=n)
+ *
+ *	     0  b  1
+ *	req: |-----|       (bo_offset=n)
+ *
+ *	     0  b  1  a' 2
+ *	new: |-----|-----| (b.bo_offset=n, a.bo_offset=n+1)
+ *
+ *    .. note::
+ *       We expect to see the same result for a request with a different BO
+ *       and/or non-contiguous BO offset.
+ *
+ *
+ * 6) Existent mapping is a superset of the requested mapping. Split it up, but
+ *    indicate that the backing PTEs could be kept.
+ *
+ *    ::
+ *
+ *	     0     a     2
+ *	old: |-----------| (bo_offset=n)
+ *
+ *	     0  a  1
+ *	req: |-----|       (bo_offset=n)
+ *
+ *	     0  a  1  a' 2
+ *	new: |-----|-----| (a.bo_offset=n, a'.bo_offset=n+1)
+ *
+ *
+ * 7) Requested mapping's range is a right aligned subset of the existent one,
+ *    but backed by a different BO. Hence, map the requested mapping and split
+ *    the existent one, without adjusting the BO offset.
+ *
+ *    ::
+ *
+ *	     0     a     2
+ *	old: |-----------| (bo_offset=n)
+ *
+ *	           1  b  2
+ *	req:       |-----| (bo_offset=m)
+ *
+ *	     0  a  1  b  2
+ *	new: |-----|-----| (a.bo_offset=n,b.bo_offset=m)
+ *
+ *
+ * 8) Existent mapping is a superset of the requested mapping. Split it up, but
+ *    indicate that the backing PTEs could be kept.
+ *
+ *    ::
+ *
+ *	      0     a     2
+ *	old: |-----------| (bo_offset=n)
+ *
+ *	           1  a  2
+ *	req:       |-----| (bo_offset=n+1)
+ *
+ *	     0  a' 1  a  2
+ *	new: |-----|-----| (a'.bo_offset=n, a.bo_offset=n+1)
+ *
+ *
+ * 9) Existent mapping is overlapped at the end by the requested mapping backed
+ *    by a different BO. Hence, map the requested mapping and split up the
+ *    existent one, without adjusting the BO offset.
+ *
+ *    ::
+ *
+ *	     0     a     2
+ *	old: |-----------|       (bo_offset=n)
+ *
+ *	           1     b     3
+ *	req:       |-----------| (bo_offset=m)
+ *
+ *	     0  a  1     b     3
+ *	new: |-----|-----------| (a.bo_offset=n,b.bo_offset=m)
+ *
+ *
+ * 10) Existent mapping is overlapped by the requested mapping, both having the
+ *     same backing BO with a contiguous offset. Indicate the backing PTEs of
+ *     the old mapping could be kept.
+ *
+ *     ::
+ *
+ *	      0     a     2
+ *	 old: |-----------|       (bo_offset=n)
+ *
+ *	            1     a     3
+ *	 req:       |-----------| (bo_offset=n+1)
+ *
+ *	      0  a' 1     a     3
+ *	 new: |-----|-----------| (a'.bo_offset=n, a.bo_offset=n+1)
+ *
+ *
+ * 11) Requested mapping's range is a centered subset of the existent one
+ *     having a different backing BO. Hence, map the requested mapping and split
+ *     up the existent one in two mappings, adjusting the BO offset of the right
+ *     one accordingly.
+ *
+ *     ::
+ *
+ *	      0        a        3
+ *	 old: |-----------------| (bo_offset=n)
+ *
+ *	            1  b  2
+ *	 req:       |-----|       (bo_offset=m)
+ *
+ *	      0  a  1  b  2  a' 3
+ *	 new: |-----|-----|-----| (a.bo_offset=n,b.bo_offset=m,a'.bo_offset=n+2)
+ *
+ *
+ * 12) Requested mapping is a contiguous subset of the existent one. Split it
+ *     up, but indicate that the backing PTEs could be kept.
+ *
+ *     ::
+ *
+ *	      0        a        3
+ *	 old: |-----------------| (bo_offset=n)
+ *
+ *	            1  a  2
+ *	 req:       |-----|       (bo_offset=n+1)
+ *
+ *	      0  a' 1  a  2 a'' 3
+ *	 old: |-----|-----|-----| (a'.bo_offset=n, a.bo_offset=n+1, a''.bo_offset=n+2)
+ *
+ *
+ * 13) Existent mapping is a right aligned subset of the requested one, hence
+ *     replace the existent one.
+ *
+ *     ::
+ *
+ *	            1  a  2
+ *	 old:       |-----| (bo_offset=n+1)
+ *
+ *	      0     a     2
+ *	 req: |-----------| (bo_offset=n)
+ *
+ *	      0     a     2
+ *	 new: |-----------| (bo_offset=n)
+ *
+ *     .. note::
+ *        We expect to see the same result for a request with a different bo
+ *        and/or non-contiguous bo_offset.
+ *
+ *
+ * 14) Existent mapping is a centered subset of the requested one, hence
+ *     replace the existent one.
+ *
+ *     ::
+ *
+ *	            1  a  2
+ *	 old:       |-----| (bo_offset=n+1)
+ *
+ *	      0        a       3
+ *	 req: |----------------| (bo_offset=n)
+ *
+ *	      0        a       3
+ *	 new: |----------------| (bo_offset=n)
+ *
+ *     .. note::
+ *        We expect to see the same result for a request with a different bo
+ *        and/or non-contiguous bo_offset.
+ *
+ *
+ * 15) Existent mappings is overlapped at the beginning by the requested mapping
+ *     backed by a different BO. Hence, map the requested mapping and split up
+ *     the existent one, adjusting its BO offset accordingly.
+ *
+ *     ::
+ *
+ *	            1     a     3
+ *	 old:       |-----------| (bo_offset=n)
+ *
+ *	      0     b     2
+ *	 req: |-----------|       (bo_offset=m)
+ *
+ *	      0     b     2  a' 3
+ *	 new: |-----------|-----| (b.bo_offset=m,a.bo_offset=n+2)
+ */
+
+/**
+ * DOC: Locking
+ *
+ * Generally, the GPU VA manager does not take care of locking itself, it is
+ * the drivers responsibility to take care about locking. Drivers might want to
+ * protect the following operations: inserting, removing and iterating
+ * &drm_gpuva objects as well as generating all kinds of operations, such as
+ * split / merge or prefetch.
+ *
+ * The GPU VA manager also does not take care of the locking of the backing
+ * &drm_gem_object buffers GPU VA lists by itself; drivers are responsible to
+ * enforce mutual exclusion using either the GEMs dma_resv lock or alternatively
+ * a driver specific external lock. For the latter see also
+ * drm_gem_gpuva_set_lock().
+ *
+ * However, the GPU VA manager contains lockdep checks to ensure callers of its
+ * API hold the corresponding lock whenever the &drm_gem_objects GPU VA list is
+ * accessed by functions such as drm_gpuva_link() or drm_gpuva_unlink().
+ */
+
+/**
+ * DOC: Examples
+ *
+ * This section gives two examples on how to let the DRM GPUVA Manager generate
+ * &drm_gpuva_op in order to satisfy a given map or unmap request and how to
+ * make use of them.
+ *
+ * The below code is strictly limited to illustrate the generic usage pattern.
+ * To maintain simplicitly, it doesn't make use of any abstractions for common
+ * code, different (asyncronous) stages with fence signalling critical paths,
+ * any other helpers or error handling in terms of freeing memory and dropping
+ * previously taken locks.
+ *
+ * 1) Obtain a list of &drm_gpuva_op to create a new mapping::
+ *
+ *	// Allocates a new &drm_gpuva.
+ *	struct drm_gpuva * driver_gpuva_alloc(void);
+ *
+ *	// Typically drivers would embedd the &drm_gpuvm and &drm_gpuva
+ *	// structure in individual driver structures and lock the dma-resv with
+ *	// drm_exec or similar helpers.
+ *	int driver_mapping_create(struct drm_gpuvm *gpuvm,
+ *				  u64 addr, u64 range,
+ *				  struct drm_gem_object *obj, u64 offset)
+ *	{
+ *		struct drm_gpuva_ops *ops;
+ *		struct drm_gpuva_op *op
+ *
+ *		driver_lock_va_space();
+ *		ops = drm_gpuvm_sm_map_ops_create(gpuvm, addr, range,
+ *						  obj, offset);
+ *		if (IS_ERR(ops))
+ *			return PTR_ERR(ops);
+ *
+ *		drm_gpuva_for_each_op(op, ops) {
+ *			struct drm_gpuva *va;
+ *
+ *			switch (op->op) {
+ *			case DRM_GPUVA_OP_MAP:
+ *				va = driver_gpuva_alloc();
+ *				if (!va)
+ *					; // unwind previous VA space updates,
+ *					  // free memory and unlock
+ *
+ *				driver_vm_map();
+ *				drm_gpuva_map(gpuvm, va, &op->map);
+ *				drm_gpuva_link(va);
+ *
+ *				break;
+ *			case DRM_GPUVA_OP_REMAP: {
+ *				struct drm_gpuva *prev = NULL, *next = NULL;
+ *
+ *				va = op->remap.unmap->va;
+ *
+ *				if (op->remap.prev) {
+ *					prev = driver_gpuva_alloc();
+ *					if (!prev)
+ *						; // unwind previous VA space
+ *						  // updates, free memory and
+ *						  // unlock
+ *				}
+ *
+ *				if (op->remap.next) {
+ *					next = driver_gpuva_alloc();
+ *					if (!next)
+ *						; // unwind previous VA space
+ *						  // updates, free memory and
+ *						  // unlock
+ *				}
+ *
+ *				driver_vm_remap();
+ *				drm_gpuva_remap(prev, next, &op->remap);
+ *
+ *				drm_gpuva_unlink(va);
+ *				if (prev)
+ *					drm_gpuva_link(prev);
+ *				if (next)
+ *					drm_gpuva_link(next);
+ *
+ *				break;
+ *			}
+ *			case DRM_GPUVA_OP_UNMAP:
+ *				va = op->unmap->va;
+ *
+ *				driver_vm_unmap();
+ *				drm_gpuva_unlink(va);
+ *				drm_gpuva_unmap(&op->unmap);
+ *
+ *				break;
+ *			default:
+ *				break;
+ *			}
+ *		}
+ *		driver_unlock_va_space();
+ *
+ *		return 0;
+ *	}
+ *
+ * 2) Receive a callback for each &drm_gpuva_op to create a new mapping::
+ *
+ *	struct driver_context {
+ *		struct drm_gpuvm *gpuvm;
+ *		struct drm_gpuva *new_va;
+ *		struct drm_gpuva *prev_va;
+ *		struct drm_gpuva *next_va;
+ *	};
+ *
+ *	// ops to pass to drm_gpuvm_init()
+ *	static const struct drm_gpuvm_ops driver_gpuvm_ops = {
+ *		.sm_step_map = driver_gpuva_map,
+ *		.sm_step_remap = driver_gpuva_remap,
+ *		.sm_step_unmap = driver_gpuva_unmap,
+ *	};
+ *
+ *	// Typically drivers would embedd the &drm_gpuvm and &drm_gpuva
+ *	// structure in individual driver structures and lock the dma-resv with
+ *	// drm_exec or similar helpers.
+ *	int driver_mapping_create(struct drm_gpuvm *gpuvm,
+ *				  u64 addr, u64 range,
+ *				  struct drm_gem_object *obj, u64 offset)
+ *	{
+ *		struct driver_context ctx;
+ *		struct drm_gpuva_ops *ops;
+ *		struct drm_gpuva_op *op;
+ *		int ret = 0;
+ *
+ *		ctx.gpuvm = gpuvm;
+ *
+ *		ctx.new_va = kzalloc(sizeof(*ctx.new_va), GFP_KERNEL);
+ *		ctx.prev_va = kzalloc(sizeof(*ctx.prev_va), GFP_KERNEL);
+ *		ctx.next_va = kzalloc(sizeof(*ctx.next_va), GFP_KERNEL);
+ *		if (!ctx.new_va || !ctx.prev_va || !ctx.next_va) {
+ *			ret = -ENOMEM;
+ *			goto out;
+ *		}
+ *
+ *		driver_lock_va_space();
+ *		ret = drm_gpuvm_sm_map(gpuvm, &ctx, addr, range, obj, offset);
+ *		driver_unlock_va_space();
+ *
+ *	out:
+ *		kfree(ctx.new_va);
+ *		kfree(ctx.prev_va);
+ *		kfree(ctx.next_va);
+ *		return ret;
+ *	}
+ *
+ *	int driver_gpuva_map(struct drm_gpuva_op *op, void *__ctx)
+ *	{
+ *		struct driver_context *ctx = __ctx;
+ *
+ *		drm_gpuva_map(ctx->vm, ctx->new_va, &op->map);
+ *
+ *		drm_gpuva_link(ctx->new_va);
+ *
+ *		// prevent the new GPUVA from being freed in
+ *		// driver_mapping_create()
+ *		ctx->new_va = NULL;
+ *
+ *		return 0;
+ *	}
+ *
+ *	int driver_gpuva_remap(struct drm_gpuva_op *op, void *__ctx)
+ *	{
+ *		struct driver_context *ctx = __ctx;
+ *
+ *		drm_gpuva_remap(ctx->prev_va, ctx->next_va, &op->remap);
+ *
+ *		drm_gpuva_unlink(op->remap.unmap->va);
+ *		kfree(op->remap.unmap->va);
+ *
+ *		if (op->remap.prev) {
+ *			drm_gpuva_link(ctx->prev_va);
+ *			ctx->prev_va = NULL;
+ *		}
+ *
+ *		if (op->remap.next) {
+ *			drm_gpuva_link(ctx->next_va);
+ *			ctx->next_va = NULL;
+ *		}
+ *
+ *		return 0;
+ *	}
+ *
+ *	int driver_gpuva_unmap(struct drm_gpuva_op *op, void *__ctx)
+ *	{
+ *		drm_gpuva_unlink(op->unmap.va);
+ *		drm_gpuva_unmap(&op->unmap);
+ *		kfree(op->unmap.va);
+ *
+ *		return 0;
+ *	}
+ */
+
+#define to_drm_gpuva(__node)	container_of((__node), struct drm_gpuva, rb.node)
+
+#define GPUVA_START(node) ((node)->va.addr)
+#define GPUVA_LAST(node) ((node)->va.addr + (node)->va.range - 1)
+
+/* We do not actually use drm_gpuva_it_next(), tell the compiler to not complain
+ * about this.
+ */
+INTERVAL_TREE_DEFINE(struct drm_gpuva, rb.node, u64, rb.__subtree_last,
+		     GPUVA_START, GPUVA_LAST, static __maybe_unused,
+		     drm_gpuva_it)
+
+static int __drm_gpuva_insert(struct drm_gpuvm *gpuvm,
+			      struct drm_gpuva *va);
+static void __drm_gpuva_remove(struct drm_gpuva *va);
+
+static bool
+drm_gpuvm_check_overflow(u64 addr, u64 range)
+{
+	u64 end;
+
+	return WARN(check_add_overflow(addr, range, &end),
+		    "GPUVA address limited to %zu bytes.\n", sizeof(end));
+}
+
+static bool
+drm_gpuvm_in_mm_range(struct drm_gpuvm *gpuvm, u64 addr, u64 range)
+{
+	u64 end = addr + range;
+	u64 mm_start = gpuvm->mm_start;
+	u64 mm_end = mm_start + gpuvm->mm_range;
+
+	return addr >= mm_start && end <= mm_end;
+}
+
+static bool
+drm_gpuvm_in_kernel_node(struct drm_gpuvm *gpuvm, u64 addr, u64 range)
+{
+	u64 end = addr + range;
+	u64 kstart = gpuvm->kernel_alloc_node.va.addr;
+	u64 krange = gpuvm->kernel_alloc_node.va.range;
+	u64 kend = kstart + krange;
+
+	return krange && addr < kend && kstart < end;
+}
+
+static bool
+drm_gpuvm_range_valid(struct drm_gpuvm *gpuvm,
+		      u64 addr, u64 range)
+{
+	return !drm_gpuvm_check_overflow(addr, range) &&
+	       drm_gpuvm_in_mm_range(gpuvm, addr, range) &&
+	       !drm_gpuvm_in_kernel_node(gpuvm, addr, range);
+}
+
+/**
+ * drm_gpuvm_init() - initialize a &drm_gpuvm
+ * @gpuvm: pointer to the &drm_gpuvm to initialize
+ * @name: the name of the GPU VA space
+ * @start_offset: the start offset of the GPU VA space
+ * @range: the size of the GPU VA space
+ * @reserve_offset: the start of the kernel reserved GPU VA area
+ * @reserve_range: the size of the kernel reserved GPU VA area
+ * @ops: &drm_gpuvm_ops called on &drm_gpuvm_sm_map / &drm_gpuvm_sm_unmap
+ *
+ * The &drm_gpuvm must be initialized with this function before use.
+ *
+ * Note that @gpuvm must be cleared to 0 before calling this function. The given
+ * &name is expected to be managed by the surrounding driver structures.
+ */
+void
+drm_gpuvm_init(struct drm_gpuvm *gpuvm,
+	       const char *name,
+	       u64 start_offset, u64 range,
+	       u64 reserve_offset, u64 reserve_range,
+	       const struct drm_gpuvm_ops *ops)
+{
+	gpuvm->rb.tree = RB_ROOT_CACHED;
+	INIT_LIST_HEAD(&gpuvm->rb.list);
+
+	drm_gpuvm_check_overflow(start_offset, range);
+	gpuvm->mm_start = start_offset;
+	gpuvm->mm_range = range;
+
+	gpuvm->name = name ? name : "unknown";
+	gpuvm->ops = ops;
+
+	memset(&gpuvm->kernel_alloc_node, 0, sizeof(struct drm_gpuva));
+
+	if (reserve_range) {
+		gpuvm->kernel_alloc_node.va.addr = reserve_offset;
+		gpuvm->kernel_alloc_node.va.range = reserve_range;
+
+		if (likely(!drm_gpuvm_check_overflow(reserve_offset,
+						     reserve_range)))
+			__drm_gpuva_insert(gpuvm, &gpuvm->kernel_alloc_node);
+	}
+}
+EXPORT_SYMBOL_GPL(drm_gpuvm_init);
+
+/**
+ * drm_gpuvm_destroy() - cleanup a &drm_gpuvm
+ * @gpuvm: pointer to the &drm_gpuvm to clean up
+ *
+ * Note that it is a bug to call this function on a manager that still
+ * holds GPU VA mappings.
+ */
+void
+drm_gpuvm_destroy(struct drm_gpuvm *gpuvm)
+{
+	gpuvm->name = NULL;
+
+	if (gpuvm->kernel_alloc_node.va.range)
+		__drm_gpuva_remove(&gpuvm->kernel_alloc_node);
+
+	WARN(!RB_EMPTY_ROOT(&gpuvm->rb.tree.rb_root),
+	     "GPUVA tree is not empty, potentially leaking memory.");
+}
+EXPORT_SYMBOL_GPL(drm_gpuvm_destroy);
+
+static int
+__drm_gpuva_insert(struct drm_gpuvm *gpuvm,
+		   struct drm_gpuva *va)
+{
+	struct rb_node *node;
+	struct list_head *head;
+
+	if (drm_gpuva_it_iter_first(&gpuvm->rb.tree,
+				    GPUVA_START(va),
+				    GPUVA_LAST(va)))
+		return -EEXIST;
+
+	va->vm = gpuvm;
+
+	drm_gpuva_it_insert(va, &gpuvm->rb.tree);
+
+	node = rb_prev(&va->rb.node);
+	if (node)
+		head = &(to_drm_gpuva(node))->rb.entry;
+	else
+		head = &gpuvm->rb.list;
+
+	list_add(&va->rb.entry, head);
+
+	return 0;
+}
+
+/**
+ * drm_gpuva_insert() - insert a &drm_gpuva
+ * @gpuvm: the &drm_gpuvm to insert the &drm_gpuva in
+ * @va: the &drm_gpuva to insert
+ *
+ * Insert a &drm_gpuva with a given address and range into a
+ * &drm_gpuvm.
+ *
+ * It is safe to use this function using the safe versions of iterating the GPU
+ * VA space, such as drm_gpuvm_for_each_va_safe() and
+ * drm_gpuvm_for_each_va_range_safe().
+ *
+ * Returns: 0 on success, negative error code on failure.
+ */
+int
+drm_gpuva_insert(struct drm_gpuvm *gpuvm,
+		 struct drm_gpuva *va)
+{
+	u64 addr = va->va.addr;
+	u64 range = va->va.range;
+
+	if (unlikely(!drm_gpuvm_range_valid(gpuvm, addr, range)))
+		return -EINVAL;
+
+	return __drm_gpuva_insert(gpuvm, va);
+}
+EXPORT_SYMBOL_GPL(drm_gpuva_insert);
+
+static void
+__drm_gpuva_remove(struct drm_gpuva *va)
+{
+	drm_gpuva_it_remove(va, &va->vm->rb.tree);
+	list_del_init(&va->rb.entry);
+}
+
+/**
+ * drm_gpuva_remove() - remove a &drm_gpuva
+ * @va: the &drm_gpuva to remove
+ *
+ * This removes the given &va from the underlaying tree.
+ *
+ * It is safe to use this function using the safe versions of iterating the GPU
+ * VA space, such as drm_gpuvm_for_each_va_safe() and
+ * drm_gpuvm_for_each_va_range_safe().
+ */
+void
+drm_gpuva_remove(struct drm_gpuva *va)
+{
+	struct drm_gpuvm *gpuvm = va->vm;
+
+	if (unlikely(va == &gpuvm->kernel_alloc_node)) {
+		WARN(1, "Can't destroy kernel reserved node.\n");
+		return;
+	}
+
+	__drm_gpuva_remove(va);
+}
+EXPORT_SYMBOL_GPL(drm_gpuva_remove);
+
+/**
+ * drm_gpuva_link() - link a &drm_gpuva
+ * @va: the &drm_gpuva to link
+ *
+ * This adds the given &va to the GPU VA list of the &drm_gem_object it is
+ * associated with.
+ *
+ * This function expects the caller to protect the GEM's GPUVA list against
+ * concurrent access using the GEMs dma_resv lock.
+ */
+void
+drm_gpuva_link(struct drm_gpuva *va)
+{
+	struct drm_gem_object *obj = va->gem.obj;
+
+	if (unlikely(!obj))
+		return;
+
+	drm_gem_gpuva_assert_lock_held(obj);
+
+	list_add_tail(&va->gem.entry, &obj->gpuva.list);
+}
+EXPORT_SYMBOL_GPL(drm_gpuva_link);
+
+/**
+ * drm_gpuva_unlink() - unlink a &drm_gpuva
+ * @va: the &drm_gpuva to unlink
+ *
+ * This removes the given &va from the GPU VA list of the &drm_gem_object it is
+ * associated with.
+ *
+ * This function expects the caller to protect the GEM's GPUVA list against
+ * concurrent access using the GEMs dma_resv lock.
+ */
+void
+drm_gpuva_unlink(struct drm_gpuva *va)
+{
+	struct drm_gem_object *obj = va->gem.obj;
+
+	if (unlikely(!obj))
+		return;
+
+	drm_gem_gpuva_assert_lock_held(obj);
+
+	list_del_init(&va->gem.entry);
+}
+EXPORT_SYMBOL_GPL(drm_gpuva_unlink);
+
+/**
+ * drm_gpuva_find_first() - find the first &drm_gpuva in the given range
+ * @gpuvm: the &drm_gpuvm to search in
+ * @addr: the &drm_gpuvas address
+ * @range: the &drm_gpuvas range
+ *
+ * Returns: the first &drm_gpuva within the given range
+ */
+struct drm_gpuva *
+drm_gpuva_find_first(struct drm_gpuvm *gpuvm,
+		     u64 addr, u64 range)
+{
+	u64 last = addr + range - 1;
+
+	return drm_gpuva_it_iter_first(&gpuvm->rb.tree, addr, last);
+}
+EXPORT_SYMBOL_GPL(drm_gpuva_find_first);
+
+/**
+ * drm_gpuva_find() - find a &drm_gpuva
+ * @gpuvm: the &drm_gpuvm to search in
+ * @addr: the &drm_gpuvas address
+ * @range: the &drm_gpuvas range
+ *
+ * Returns: the &drm_gpuva at a given &addr and with a given &range
+ */
+struct drm_gpuva *
+drm_gpuva_find(struct drm_gpuvm *gpuvm,
+	       u64 addr, u64 range)
+{
+	struct drm_gpuva *va;
+
+	va = drm_gpuva_find_first(gpuvm, addr, range);
+	if (!va)
+		goto out;
+
+	if (va->va.addr != addr ||
+	    va->va.range != range)
+		goto out;
+
+	return va;
+
+out:
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(drm_gpuva_find);
+
+/**
+ * drm_gpuva_find_prev() - find the &drm_gpuva before the given address
+ * @gpuvm: the &drm_gpuvm to search in
+ * @start: the given GPU VA's start address
+ *
+ * Find the adjacent &drm_gpuva before the GPU VA with given &start address.
+ *
+ * Note that if there is any free space between the GPU VA mappings no mapping
+ * is returned.
+ *
+ * Returns: a pointer to the found &drm_gpuva or NULL if none was found
+ */
+struct drm_gpuva *
+drm_gpuva_find_prev(struct drm_gpuvm *gpuvm, u64 start)
+{
+	if (!drm_gpuvm_range_valid(gpuvm, start - 1, 1))
+		return NULL;
+
+	return drm_gpuva_it_iter_first(&gpuvm->rb.tree, start - 1, start);
+}
+EXPORT_SYMBOL_GPL(drm_gpuva_find_prev);
+
+/**
+ * drm_gpuva_find_next() - find the &drm_gpuva after the given address
+ * @gpuvm: the &drm_gpuvm to search in
+ * @end: the given GPU VA's end address
+ *
+ * Find the adjacent &drm_gpuva after the GPU VA with given &end address.
+ *
+ * Note that if there is any free space between the GPU VA mappings no mapping
+ * is returned.
+ *
+ * Returns: a pointer to the found &drm_gpuva or NULL if none was found
+ */
+struct drm_gpuva *
+drm_gpuva_find_next(struct drm_gpuvm *gpuvm, u64 end)
+{
+	if (!drm_gpuvm_range_valid(gpuvm, end, 1))
+		return NULL;
+
+	return drm_gpuva_it_iter_first(&gpuvm->rb.tree, end, end + 1);
+}
+EXPORT_SYMBOL_GPL(drm_gpuva_find_next);
+
+/**
+ * drm_gpuvm_interval_empty() - indicate whether a given interval of the VA space
+ * is empty
+ * @gpuvm: the &drm_gpuvm to check the range for
+ * @addr: the start address of the range
+ * @range: the range of the interval
+ *
+ * Returns: true if the interval is empty, false otherwise
+ */
+bool
+drm_gpuvm_interval_empty(struct drm_gpuvm *gpuvm, u64 addr, u64 range)
+{
+	return !drm_gpuva_find_first(gpuvm, addr, range);
+}
+EXPORT_SYMBOL_GPL(drm_gpuvm_interval_empty);
+
+/**
+ * drm_gpuva_map() - helper to insert a &drm_gpuva according to a
+ * &drm_gpuva_op_map
+ * @gpuvm: the &drm_gpuvm
+ * @va: the &drm_gpuva to insert
+ * @op: the &drm_gpuva_op_map to initialize @va with
+ *
+ * Initializes the @va from the @op and inserts it into the given @gpuvm.
+ */
+void
+drm_gpuva_map(struct drm_gpuvm *gpuvm,
+	      struct drm_gpuva *va,
+	      struct drm_gpuva_op_map *op)
+{
+	drm_gpuva_init_from_op(va, op);
+	drm_gpuva_insert(gpuvm, va);
+}
+EXPORT_SYMBOL_GPL(drm_gpuva_map);
+
+/**
+ * drm_gpuva_remap() - helper to remap a &drm_gpuva according to a
+ * &drm_gpuva_op_remap
+ * @prev: the &drm_gpuva to remap when keeping the start of a mapping
+ * @next: the &drm_gpuva to remap when keeping the end of a mapping
+ * @op: the &drm_gpuva_op_remap to initialize @prev and @next with
+ *
+ * Removes the currently mapped &drm_gpuva and remaps it using @prev and/or
+ * @next.
+ */
+void
+drm_gpuva_remap(struct drm_gpuva *prev,
+		struct drm_gpuva *next,
+		struct drm_gpuva_op_remap *op)
+{
+	struct drm_gpuva *curr = op->unmap->va;
+	struct drm_gpuvm *gpuvm = curr->vm;
+
+	drm_gpuva_remove(curr);
+
+	if (op->prev) {
+		drm_gpuva_init_from_op(prev, op->prev);
+		drm_gpuva_insert(gpuvm, prev);
+	}
+
+	if (op->next) {
+		drm_gpuva_init_from_op(next, op->next);
+		drm_gpuva_insert(gpuvm, next);
+	}
+}
+EXPORT_SYMBOL_GPL(drm_gpuva_remap);
+
+/**
+ * drm_gpuva_unmap() - helper to remove a &drm_gpuva according to a
+ * &drm_gpuva_op_unmap
+ * @op: the &drm_gpuva_op_unmap specifying the &drm_gpuva to remove
+ *
+ * Removes the &drm_gpuva associated with the &drm_gpuva_op_unmap.
+ */
+void
+drm_gpuva_unmap(struct drm_gpuva_op_unmap *op)
+{
+	drm_gpuva_remove(op->va);
+}
+EXPORT_SYMBOL_GPL(drm_gpuva_unmap);
+
+static int
+op_map_cb(const struct drm_gpuvm_ops *fn, void *priv,
+	  u64 addr, u64 range,
+	  struct drm_gem_object *obj, u64 offset)
+{
+	struct drm_gpuva_op op = {};
+
+	op.op = DRM_GPUVA_OP_MAP;
+	op.map.va.addr = addr;
+	op.map.va.range = range;
+	op.map.gem.obj = obj;
+	op.map.gem.offset = offset;
+
+	return fn->sm_step_map(&op, priv);
+}
+
+static int
+op_remap_cb(const struct drm_gpuvm_ops *fn, void *priv,
+	    struct drm_gpuva_op_map *prev,
+	    struct drm_gpuva_op_map *next,
+	    struct drm_gpuva_op_unmap *unmap)
+{
+	struct drm_gpuva_op op = {};
+	struct drm_gpuva_op_remap *r;
+
+	op.op = DRM_GPUVA_OP_REMAP;
+	r = &op.remap;
+	r->prev = prev;
+	r->next = next;
+	r->unmap = unmap;
+
+	return fn->sm_step_remap(&op, priv);
+}
+
+static int
+op_unmap_cb(const struct drm_gpuvm_ops *fn, void *priv,
+	    struct drm_gpuva *va, bool merge)
+{
+	struct drm_gpuva_op op = {};
+
+	op.op = DRM_GPUVA_OP_UNMAP;
+	op.unmap.va = va;
+	op.unmap.keep = merge;
+
+	return fn->sm_step_unmap(&op, priv);
+}
+
+static int
+__drm_gpuvm_sm_map(struct drm_gpuvm *gpuvm,
+		   const struct drm_gpuvm_ops *ops, void *priv,
+		   u64 req_addr, u64 req_range,
+		   struct drm_gem_object *req_obj, u64 req_offset)
+{
+	struct drm_gpuva *va, *next;
+	u64 req_end = req_addr + req_range;
+	int ret;
+
+	if (unlikely(!drm_gpuvm_range_valid(gpuvm, req_addr, req_range)))
+		return -EINVAL;
+
+	drm_gpuvm_for_each_va_range_safe(va, next, gpuvm, req_addr, req_end) {
+		struct drm_gem_object *obj = va->gem.obj;
+		u64 offset = va->gem.offset;
+		u64 addr = va->va.addr;
+		u64 range = va->va.range;
+		u64 end = addr + range;
+		bool merge = !!va->gem.obj;
+
+		if (addr == req_addr) {
+			merge &= obj == req_obj &&
+				 offset == req_offset;
+
+			if (end == req_end) {
+				ret = op_unmap_cb(ops, priv, va, merge);
+				if (ret)
+					return ret;
+				break;
+			}
+
+			if (end < req_end) {
+				ret = op_unmap_cb(ops, priv, va, merge);
+				if (ret)
+					return ret;
+				continue;
+			}
+
+			if (end > req_end) {
+				struct drm_gpuva_op_map n = {
+					.va.addr = req_end,
+					.va.range = range - req_range,
+					.gem.obj = obj,
+					.gem.offset = offset + req_range,
+				};
+				struct drm_gpuva_op_unmap u = {
+					.va = va,
+					.keep = merge,
+				};
+
+				ret = op_remap_cb(ops, priv, NULL, &n, &u);
+				if (ret)
+					return ret;
+				break;
+			}
+		} else if (addr < req_addr) {
+			u64 ls_range = req_addr - addr;
+			struct drm_gpuva_op_map p = {
+				.va.addr = addr,
+				.va.range = ls_range,
+				.gem.obj = obj,
+				.gem.offset = offset,
+			};
+			struct drm_gpuva_op_unmap u = { .va = va };
+
+			merge &= obj == req_obj &&
+				 offset + ls_range == req_offset;
+			u.keep = merge;
+
+			if (end == req_end) {
+				ret = op_remap_cb(ops, priv, &p, NULL, &u);
+				if (ret)
+					return ret;
+				break;
+			}
+
+			if (end < req_end) {
+				ret = op_remap_cb(ops, priv, &p, NULL, &u);
+				if (ret)
+					return ret;
+				continue;
+			}
+
+			if (end > req_end) {
+				struct drm_gpuva_op_map n = {
+					.va.addr = req_end,
+					.va.range = end - req_end,
+					.gem.obj = obj,
+					.gem.offset = offset + ls_range +
+						      req_range,
+				};
+
+				ret = op_remap_cb(ops, priv, &p, &n, &u);
+				if (ret)
+					return ret;
+				break;
+			}
+		} else if (addr > req_addr) {
+			merge &= obj == req_obj &&
+				 offset == req_offset +
+					   (addr - req_addr);
+
+			if (end == req_end) {
+				ret = op_unmap_cb(ops, priv, va, merge);
+				if (ret)
+					return ret;
+				break;
+			}
+
+			if (end < req_end) {
+				ret = op_unmap_cb(ops, priv, va, merge);
+				if (ret)
+					return ret;
+				continue;
+			}
+
+			if (end > req_end) {
+				struct drm_gpuva_op_map n = {
+					.va.addr = req_end,
+					.va.range = end - req_end,
+					.gem.obj = obj,
+					.gem.offset = offset + req_end - addr,
+				};
+				struct drm_gpuva_op_unmap u = {
+					.va = va,
+					.keep = merge,
+				};
+
+				ret = op_remap_cb(ops, priv, NULL, &n, &u);
+				if (ret)
+					return ret;
+				break;
+			}
+		}
+	}
+
+	return op_map_cb(ops, priv,
+			 req_addr, req_range,
+			 req_obj, req_offset);
+}
+
+static int
+__drm_gpuvm_sm_unmap(struct drm_gpuvm *gpuvm,
+		     const struct drm_gpuvm_ops *ops, void *priv,
+		     u64 req_addr, u64 req_range)
+{
+	struct drm_gpuva *va, *next;
+	u64 req_end = req_addr + req_range;
+	int ret;
+
+	if (unlikely(!drm_gpuvm_range_valid(gpuvm, req_addr, req_range)))
+		return -EINVAL;
+
+	drm_gpuvm_for_each_va_range_safe(va, next, gpuvm, req_addr, req_end) {
+		struct drm_gpuva_op_map prev = {}, next = {};
+		bool prev_split = false, next_split = false;
+		struct drm_gem_object *obj = va->gem.obj;
+		u64 offset = va->gem.offset;
+		u64 addr = va->va.addr;
+		u64 range = va->va.range;
+		u64 end = addr + range;
+
+		if (addr < req_addr) {
+			prev.va.addr = addr;
+			prev.va.range = req_addr - addr;
+			prev.gem.obj = obj;
+			prev.gem.offset = offset;
+
+			prev_split = true;
+		}
+
+		if (end > req_end) {
+			next.va.addr = req_end;
+			next.va.range = end - req_end;
+			next.gem.obj = obj;
+			next.gem.offset = offset + (req_end - addr);
+
+			next_split = true;
+		}
+
+		if (prev_split || next_split) {
+			struct drm_gpuva_op_unmap unmap = { .va = va };
+
+			ret = op_remap_cb(ops, priv,
+					  prev_split ? &prev : NULL,
+					  next_split ? &next : NULL,
+					  &unmap);
+			if (ret)
+				return ret;
+		} else {
+			ret = op_unmap_cb(ops, priv, va, false);
+			if (ret)
+				return ret;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * drm_gpuvm_sm_map() - creates the &drm_gpuva_op split/merge steps
+ * @gpuvm: the &drm_gpuvm representing the GPU VA space
+ * @req_addr: the start address of the new mapping
+ * @req_range: the range of the new mapping
+ * @req_obj: the &drm_gem_object to map
+ * @req_offset: the offset within the &drm_gem_object
+ * @priv: pointer to a driver private data structure
+ *
+ * This function iterates the given range of the GPU VA space. It utilizes the
+ * &drm_gpuvm_ops to call back into the driver providing the split and merge
+ * steps.
+ *
+ * Drivers may use these callbacks to update the GPU VA space right away within
+ * the callback. In case the driver decides to copy and store the operations for
+ * later processing neither this function nor &drm_gpuvm_sm_unmap is allowed to
+ * be called before the &drm_gpuvm's view of the GPU VA space was
+ * updated with the previous set of operations. To update the
+ * &drm_gpuvm's view of the GPU VA space drm_gpuva_insert(),
+ * drm_gpuva_destroy_locked() and/or drm_gpuva_destroy_unlocked() should be
+ * used.
+ *
+ * A sequence of callbacks can contain map, unmap and remap operations, but
+ * the sequence of callbacks might also be empty if no operation is required,
+ * e.g. if the requested mapping already exists in the exact same way.
+ *
+ * There can be an arbitrary amount of unmap operations, a maximum of two remap
+ * operations and a single map operation. The latter one represents the original
+ * map operation requested by the caller.
+ *
+ * Returns: 0 on success or a negative error code
+ */
+int
+drm_gpuvm_sm_map(struct drm_gpuvm *gpuvm, void *priv,
+		 u64 req_addr, u64 req_range,
+		 struct drm_gem_object *req_obj, u64 req_offset)
+{
+	const struct drm_gpuvm_ops *ops = gpuvm->ops;
+
+	if (unlikely(!(ops && ops->sm_step_map &&
+		       ops->sm_step_remap &&
+		       ops->sm_step_unmap)))
+		return -EINVAL;
+
+	return __drm_gpuvm_sm_map(gpuvm, ops, priv,
+				  req_addr, req_range,
+				  req_obj, req_offset);
+}
+EXPORT_SYMBOL_GPL(drm_gpuvm_sm_map);
+
+/**
+ * drm_gpuvm_sm_unmap() - creates the &drm_gpuva_ops to split on unmap
+ * @gpuvm: the &drm_gpuvm representing the GPU VA space
+ * @priv: pointer to a driver private data structure
+ * @req_addr: the start address of the range to unmap
+ * @req_range: the range of the mappings to unmap
+ *
+ * This function iterates the given range of the GPU VA space. It utilizes the
+ * &drm_gpuvm_ops to call back into the driver providing the operations to
+ * unmap and, if required, split existent mappings.
+ *
+ * Drivers may use these callbacks to update the GPU VA space right away within
+ * the callback. In case the driver decides to copy and store the operations for
+ * later processing neither this function nor &drm_gpuvm_sm_map is allowed to be
+ * called before the &drm_gpuvm's view of the GPU VA space was updated
+ * with the previous set of operations. To update the &drm_gpuvm's view
+ * of the GPU VA space drm_gpuva_insert(), drm_gpuva_destroy_locked() and/or
+ * drm_gpuva_destroy_unlocked() should be used.
+ *
+ * A sequence of callbacks can contain unmap and remap operations, depending on
+ * whether there are actual overlapping mappings to split.
+ *
+ * There can be an arbitrary amount of unmap operations and a maximum of two
+ * remap operations.
+ *
+ * Returns: 0 on success or a negative error code
+ */
+int
+drm_gpuvm_sm_unmap(struct drm_gpuvm *gpuvm, void *priv,
+		   u64 req_addr, u64 req_range)
+{
+	const struct drm_gpuvm_ops *ops = gpuvm->ops;
+
+	if (unlikely(!(ops && ops->sm_step_remap &&
+		       ops->sm_step_unmap)))
+		return -EINVAL;
+
+	return __drm_gpuvm_sm_unmap(gpuvm, ops, priv,
+				    req_addr, req_range);
+}
+EXPORT_SYMBOL_GPL(drm_gpuvm_sm_unmap);
+
+static struct drm_gpuva_op *
+gpuva_op_alloc(struct drm_gpuvm *gpuvm)
+{
+	const struct drm_gpuvm_ops *fn = gpuvm->ops;
+	struct drm_gpuva_op *op;
+
+	if (fn && fn->op_alloc)
+		op = fn->op_alloc();
+	else
+		op = kzalloc(sizeof(*op), GFP_KERNEL);
+
+	if (unlikely(!op))
+		return NULL;
+
+	return op;
+}
+
+static void
+gpuva_op_free(struct drm_gpuvm *gpuvm,
+	      struct drm_gpuva_op *op)
+{
+	const struct drm_gpuvm_ops *fn = gpuvm->ops;
+
+	if (fn && fn->op_free)
+		fn->op_free(op);
+	else
+		kfree(op);
+}
+
+static int
+drm_gpuva_sm_step(struct drm_gpuva_op *__op,
+		  void *priv)
+{
+	struct {
+		struct drm_gpuvm *vm;
+		struct drm_gpuva_ops *ops;
+	} *args = priv;
+	struct drm_gpuvm *gpuvm = args->vm;
+	struct drm_gpuva_ops *ops = args->ops;
+	struct drm_gpuva_op *op;
+
+	op = gpuva_op_alloc(gpuvm);
+	if (unlikely(!op))
+		goto err;
+
+	memcpy(op, __op, sizeof(*op));
+
+	if (op->op == DRM_GPUVA_OP_REMAP) {
+		struct drm_gpuva_op_remap *__r = &__op->remap;
+		struct drm_gpuva_op_remap *r = &op->remap;
+
+		r->unmap = kmemdup(__r->unmap, sizeof(*r->unmap),
+				   GFP_KERNEL);
+		if (unlikely(!r->unmap))
+			goto err_free_op;
+
+		if (__r->prev) {
+			r->prev = kmemdup(__r->prev, sizeof(*r->prev),
+					  GFP_KERNEL);
+			if (unlikely(!r->prev))
+				goto err_free_unmap;
+		}
+
+		if (__r->next) {
+			r->next = kmemdup(__r->next, sizeof(*r->next),
+					  GFP_KERNEL);
+			if (unlikely(!r->next))
+				goto err_free_prev;
+		}
+	}
+
+	list_add_tail(&op->entry, &ops->list);
+
+	return 0;
+
+err_free_unmap:
+	kfree(op->remap.unmap);
+err_free_prev:
+	kfree(op->remap.prev);
+err_free_op:
+	gpuva_op_free(gpuvm, op);
+err:
+	return -ENOMEM;
+}
+
+static const struct drm_gpuvm_ops gpuvm_list_ops = {
+	.sm_step_map = drm_gpuva_sm_step,
+	.sm_step_remap = drm_gpuva_sm_step,
+	.sm_step_unmap = drm_gpuva_sm_step,
+};
+
+/**
+ * drm_gpuvm_sm_map_ops_create() - creates the &drm_gpuva_ops to split and merge
+ * @gpuvm: the &drm_gpuvm representing the GPU VA space
+ * @req_addr: the start address of the new mapping
+ * @req_range: the range of the new mapping
+ * @req_obj: the &drm_gem_object to map
+ * @req_offset: the offset within the &drm_gem_object
+ *
+ * This function creates a list of operations to perform splitting and merging
+ * of existent mapping(s) with the newly requested one.
+ *
+ * The list can be iterated with &drm_gpuva_for_each_op and must be processed
+ * in the given order. It can contain map, unmap and remap operations, but it
+ * also can be empty if no operation is required, e.g. if the requested mapping
+ * already exists is the exact same way.
+ *
+ * There can be an arbitrary amount of unmap operations, a maximum of two remap
+ * operations and a single map operation. The latter one represents the original
+ * map operation requested by the caller.
+ *
+ * Note that before calling this function again with another mapping request it
+ * is necessary to update the &drm_gpuvm's view of the GPU VA space. The
+ * previously obtained operations must be either processed or abandoned. To
+ * update the &drm_gpuvm's view of the GPU VA space drm_gpuva_insert(),
+ * drm_gpuva_destroy_locked() and/or drm_gpuva_destroy_unlocked() should be
+ * used.
+ *
+ * After the caller finished processing the returned &drm_gpuva_ops, they must
+ * be freed with &drm_gpuva_ops_free.
+ *
+ * Returns: a pointer to the &drm_gpuva_ops on success, an ERR_PTR on failure
+ */
+struct drm_gpuva_ops *
+drm_gpuvm_sm_map_ops_create(struct drm_gpuvm *gpuvm,
+			    u64 req_addr, u64 req_range,
+			    struct drm_gem_object *req_obj, u64 req_offset)
+{
+	struct drm_gpuva_ops *ops;
+	struct {
+		struct drm_gpuvm *vm;
+		struct drm_gpuva_ops *ops;
+	} args;
+	int ret;
+
+	ops = kzalloc(sizeof(*ops), GFP_KERNEL);
+	if (unlikely(!ops))
+		return ERR_PTR(-ENOMEM);
+
+	INIT_LIST_HEAD(&ops->list);
+
+	args.vm = gpuvm;
+	args.ops = ops;
+
+	ret = __drm_gpuvm_sm_map(gpuvm, &gpuvm_list_ops, &args,
+				 req_addr, req_range,
+				 req_obj, req_offset);
+	if (ret)
+		goto err_free_ops;
+
+	return ops;
+
+err_free_ops:
+	drm_gpuva_ops_free(gpuvm, ops);
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(drm_gpuvm_sm_map_ops_create);
+
+/**
+ * drm_gpuvm_sm_unmap_ops_create() - creates the &drm_gpuva_ops to split on
+ * unmap
+ * @gpuvm: the &drm_gpuvm representing the GPU VA space
+ * @req_addr: the start address of the range to unmap
+ * @req_range: the range of the mappings to unmap
+ *
+ * This function creates a list of operations to perform unmapping and, if
+ * required, splitting of the mappings overlapping the unmap range.
+ *
+ * The list can be iterated with &drm_gpuva_for_each_op and must be processed
+ * in the given order. It can contain unmap and remap operations, depending on
+ * whether there are actual overlapping mappings to split.
+ *
+ * There can be an arbitrary amount of unmap operations and a maximum of two
+ * remap operations.
+ *
+ * Note that before calling this function again with another range to unmap it
+ * is necessary to update the &drm_gpuvm's view of the GPU VA space. The
+ * previously obtained operations must be processed or abandoned. To update the
+ * &drm_gpuvm's view of the GPU VA space drm_gpuva_insert(),
+ * drm_gpuva_destroy_locked() and/or drm_gpuva_destroy_unlocked() should be
+ * used.
+ *
+ * After the caller finished processing the returned &drm_gpuva_ops, they must
+ * be freed with &drm_gpuva_ops_free.
+ *
+ * Returns: a pointer to the &drm_gpuva_ops on success, an ERR_PTR on failure
+ */
+struct drm_gpuva_ops *
+drm_gpuvm_sm_unmap_ops_create(struct drm_gpuvm *gpuvm,
+			      u64 req_addr, u64 req_range)
+{
+	struct drm_gpuva_ops *ops;
+	struct {
+		struct drm_gpuvm *vm;
+		struct drm_gpuva_ops *ops;
+	} args;
+	int ret;
+
+	ops = kzalloc(sizeof(*ops), GFP_KERNEL);
+	if (unlikely(!ops))
+		return ERR_PTR(-ENOMEM);
+
+	INIT_LIST_HEAD(&ops->list);
+
+	args.vm = gpuvm;
+	args.ops = ops;
+
+	ret = __drm_gpuvm_sm_unmap(gpuvm, &gpuvm_list_ops, &args,
+				   req_addr, req_range);
+	if (ret)
+		goto err_free_ops;
+
+	return ops;
+
+err_free_ops:
+	drm_gpuva_ops_free(gpuvm, ops);
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(drm_gpuvm_sm_unmap_ops_create);
+
+/**
+ * drm_gpuvm_prefetch_ops_create() - creates the &drm_gpuva_ops to prefetch
+ * @gpuvm: the &drm_gpuvm representing the GPU VA space
+ * @addr: the start address of the range to prefetch
+ * @range: the range of the mappings to prefetch
+ *
+ * This function creates a list of operations to perform prefetching.
+ *
+ * The list can be iterated with &drm_gpuva_for_each_op and must be processed
+ * in the given order. It can contain prefetch operations.
+ *
+ * There can be an arbitrary amount of prefetch operations.
+ *
+ * After the caller finished processing the returned &drm_gpuva_ops, they must
+ * be freed with &drm_gpuva_ops_free.
+ *
+ * Returns: a pointer to the &drm_gpuva_ops on success, an ERR_PTR on failure
+ */
+struct drm_gpuva_ops *
+drm_gpuvm_prefetch_ops_create(struct drm_gpuvm *gpuvm,
+			      u64 addr, u64 range)
+{
+	struct drm_gpuva_ops *ops;
+	struct drm_gpuva_op *op;
+	struct drm_gpuva *va;
+	u64 end = addr + range;
+	int ret;
+
+	ops = kzalloc(sizeof(*ops), GFP_KERNEL);
+	if (!ops)
+		return ERR_PTR(-ENOMEM);
+
+	INIT_LIST_HEAD(&ops->list);
+
+	drm_gpuvm_for_each_va_range(va, gpuvm, addr, end) {
+		op = gpuva_op_alloc(gpuvm);
+		if (!op) {
+			ret = -ENOMEM;
+			goto err_free_ops;
+		}
+
+		op->op = DRM_GPUVA_OP_PREFETCH;
+		op->prefetch.va = va;
+		list_add_tail(&op->entry, &ops->list);
+	}
+
+	return ops;
+
+err_free_ops:
+	drm_gpuva_ops_free(gpuvm, ops);
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(drm_gpuvm_prefetch_ops_create);
+
+/**
+ * drm_gpuvm_gem_unmap_ops_create() - creates the &drm_gpuva_ops to unmap a GEM
+ * @gpuvm: the &drm_gpuvm representing the GPU VA space
+ * @obj: the &drm_gem_object to unmap
+ *
+ * This function creates a list of operations to perform unmapping for every
+ * GPUVA attached to a GEM.
+ *
+ * The list can be iterated with &drm_gpuva_for_each_op and consists out of an
+ * arbitrary amount of unmap operations.
+ *
+ * After the caller finished processing the returned &drm_gpuva_ops, they must
+ * be freed with &drm_gpuva_ops_free.
+ *
+ * It is the callers responsibility to protect the GEMs GPUVA list against
+ * concurrent access using the GEMs dma_resv lock.
+ *
+ * Returns: a pointer to the &drm_gpuva_ops on success, an ERR_PTR on failure
+ */
+struct drm_gpuva_ops *
+drm_gpuvm_gem_unmap_ops_create(struct drm_gpuvm *gpuvm,
+			       struct drm_gem_object *obj)
+{
+	struct drm_gpuva_ops *ops;
+	struct drm_gpuva_op *op;
+	struct drm_gpuva *va;
+	int ret;
+
+	drm_gem_gpuva_assert_lock_held(obj);
+
+	ops = kzalloc(sizeof(*ops), GFP_KERNEL);
+	if (!ops)
+		return ERR_PTR(-ENOMEM);
+
+	INIT_LIST_HEAD(&ops->list);
+
+	drm_gem_for_each_gpuva(va, obj) {
+		op = gpuva_op_alloc(gpuvm);
+		if (!op) {
+			ret = -ENOMEM;
+			goto err_free_ops;
+		}
+
+		op->op = DRM_GPUVA_OP_UNMAP;
+		op->unmap.va = va;
+		list_add_tail(&op->entry, &ops->list);
+	}
+
+	return ops;
+
+err_free_ops:
+	drm_gpuva_ops_free(gpuvm, ops);
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(drm_gpuvm_gem_unmap_ops_create);
+
+/**
+ * drm_gpuva_ops_free() - free the given &drm_gpuva_ops
+ * @gpuvm: the &drm_gpuvm the ops were created for
+ * @ops: the &drm_gpuva_ops to free
+ *
+ * Frees the given &drm_gpuva_ops structure including all the ops associated
+ * with it.
+ */
+void
+drm_gpuva_ops_free(struct drm_gpuvm *gpuvm,
+		   struct drm_gpuva_ops *ops)
+{
+	struct drm_gpuva_op *op, *next;
+
+	drm_gpuva_for_each_op_safe(op, next, ops) {
+		list_del(&op->entry);
+
+		if (op->op == DRM_GPUVA_OP_REMAP) {
+			kfree(op->remap.prev);
+			kfree(op->remap.next);
+			kfree(op->remap.unmap);
+		}
+
+		gpuva_op_free(gpuvm, op);
+	}
+
+	kfree(ops);
+}
+EXPORT_SYMBOL_GPL(drm_gpuva_ops_free);
--- a/drivers/gpu/drm/nouveau/nouveau_exec.c
+++ b/drivers/gpu/drm/nouveau/nouveau_exec.c
@@ -107,7 +107,7 @@ nouveau_exec_job_submit(struct nouveau_j
 	drm_exec_until_all_locked(exec) {
 		struct drm_gpuva *va;
 
-		drm_gpuva_for_each_va(va, &uvmm->umgr) {
+		drm_gpuvm_for_each_va(va, &uvmm->umgr) {
 			if (unlikely(va == &uvmm->umgr.kernel_alloc_node))
 				continue;
 
--- a/drivers/gpu/drm/nouveau/nouveau_uvmm.c
+++ b/drivers/gpu/drm/nouveau/nouveau_uvmm.c
@@ -329,7 +329,7 @@ nouveau_uvma_region_create(struct nouvea
 	struct nouveau_uvma_region *reg;
 	int ret;
 
-	if (!drm_gpuva_interval_empty(&uvmm->umgr, addr, range))
+	if (!drm_gpuvm_interval_empty(&uvmm->umgr, addr, range))
 		return -ENOSPC;
 
 	ret = nouveau_uvma_region_alloc(&reg);
@@ -384,7 +384,7 @@ nouveau_uvma_region_empty(struct nouveau
 {
 	struct nouveau_uvmm *uvmm = reg->uvmm;
 
-	return drm_gpuva_interval_empty(&uvmm->umgr,
+	return drm_gpuvm_interval_empty(&uvmm->umgr,
 					reg->va.addr,
 					reg->va.range);
 }
@@ -444,7 +444,7 @@ op_map_prepare_unwind(struct nouveau_uvm
 static void
 op_unmap_prepare_unwind(struct drm_gpuva *va)
 {
-	drm_gpuva_insert(va->mgr, va);
+	drm_gpuva_insert(va->vm, va);
 }
 
 static void
@@ -1194,7 +1194,7 @@ nouveau_uvmm_bind_job_submit(struct nouv
 				goto unwind_continue;
 			}
 
-			op->ops = drm_gpuva_sm_unmap_ops_create(&uvmm->umgr,
+			op->ops = drm_gpuvm_sm_unmap_ops_create(&uvmm->umgr,
 								op->va.addr,
 								op->va.range);
 			if (IS_ERR(op->ops)) {
@@ -1240,7 +1240,7 @@ nouveau_uvmm_bind_job_submit(struct nouv
 				}
 			}
 
-			op->ops = drm_gpuva_sm_map_ops_create(&uvmm->umgr,
+			op->ops = drm_gpuvm_sm_map_ops_create(&uvmm->umgr,
 							      op->va.addr,
 							      op->va.range,
 							      op->gem.obj,
@@ -1264,7 +1264,7 @@ nouveau_uvmm_bind_job_submit(struct nouv
 			break;
 		}
 		case OP_UNMAP:
-			op->ops = drm_gpuva_sm_unmap_ops_create(&uvmm->umgr,
+			op->ops = drm_gpuvm_sm_unmap_ops_create(&uvmm->umgr,
 								op->va.addr,
 								op->va.range);
 			if (IS_ERR(op->ops)) {
@@ -1836,11 +1836,11 @@ nouveau_uvmm_init(struct nouveau_uvmm *u
 	uvmm->kernel_managed_addr = kernel_managed_addr;
 	uvmm->kernel_managed_size = kernel_managed_size;
 
-	drm_gpuva_manager_init(&uvmm->umgr, cli->name,
-			       NOUVEAU_VA_SPACE_START,
-			       NOUVEAU_VA_SPACE_END,
-			       kernel_managed_addr, kernel_managed_size,
-			       NULL);
+	drm_gpuvm_init(&uvmm->umgr, cli->name,
+		       NOUVEAU_VA_SPACE_START,
+		       NOUVEAU_VA_SPACE_END,
+		       kernel_managed_addr, kernel_managed_size,
+		       NULL);
 
 	ret = nvif_vmm_ctor(&cli->mmu, "uvmm",
 			    cli->vmm.vmm.object.oclass, RAW,
@@ -1855,7 +1855,7 @@ nouveau_uvmm_init(struct nouveau_uvmm *u
 	return 0;
 
 out_free_gpuva_mgr:
-	drm_gpuva_manager_destroy(&uvmm->umgr);
+	drm_gpuvm_destroy(&uvmm->umgr);
 out_unlock:
 	mutex_unlock(&cli->mutex);
 	return ret;
@@ -1877,7 +1877,7 @@ nouveau_uvmm_fini(struct nouveau_uvmm *u
 	wait_event(entity->job.wq, list_empty(&entity->job.list.head));
 
 	nouveau_uvmm_lock(uvmm);
-	drm_gpuva_for_each_va_safe(va, next, &uvmm->umgr) {
+	drm_gpuvm_for_each_va_safe(va, next, &uvmm->umgr) {
 		struct nouveau_uvma *uvma = uvma_from_va(va);
 		struct drm_gem_object *obj = va->gem.obj;
 
@@ -1910,7 +1910,7 @@ nouveau_uvmm_fini(struct nouveau_uvmm *u
 
 	mutex_lock(&cli->mutex);
 	nouveau_vmm_fini(&uvmm->vmm);
-	drm_gpuva_manager_destroy(&uvmm->umgr);
+	drm_gpuvm_destroy(&uvmm->umgr);
 	mutex_unlock(&cli->mutex);
 
 	dma_resv_fini(&uvmm->resv);
--- a/drivers/gpu/drm/nouveau/nouveau_uvmm.h
+++ b/drivers/gpu/drm/nouveau/nouveau_uvmm.h
@@ -3,13 +3,13 @@
 #ifndef __NOUVEAU_UVMM_H__
 #define __NOUVEAU_UVMM_H__
 
-#include <drm/drm_gpuva_mgr.h>
+#include <drm/drm_gpuvm.h>
 
 #include "nouveau_drv.h"
 
 struct nouveau_uvmm {
 	struct nouveau_vmm vmm;
-	struct drm_gpuva_manager umgr;
+	struct drm_gpuvm umgr;
 	struct maple_tree region_mt;
 	struct mutex mutex;
 	struct dma_resv resv;
@@ -44,7 +44,7 @@ struct nouveau_uvma {
 #define uvmm_from_mgr(x) container_of((x), struct nouveau_uvmm, umgr)
 #define uvma_from_va(x) container_of((x), struct nouveau_uvma, va)
 
-#define to_uvmm(x) uvmm_from_mgr((x)->va.mgr)
+#define to_uvmm(x) uvmm_from_mgr((x)->va.vm)
 
 struct nouveau_uvmm_bind_job {
 	struct nouveau_job base;
--- a/include/drm/drm_debugfs.h
+++ b/include/drm/drm_debugfs.h
@@ -35,7 +35,7 @@
 #include <linux/types.h>
 #include <linux/seq_file.h>
 
-#include <drm/drm_gpuva_mgr.h>
+#include <drm/drm_gpuvm.h>
 
 /**
  * DRM_DEBUGFS_GPUVA_INFO - &drm_info_list entry to dump a GPU VA space
@@ -152,7 +152,7 @@ void drm_debugfs_add_files(struct drm_de
 			   const struct drm_debugfs_info *files, int count);
 
 int drm_debugfs_gpuva_info(struct seq_file *m,
-			   struct drm_gpuva_manager *mgr);
+			   struct drm_gpuvm *gpuvm);
 #else
 static inline void drm_debugfs_create_files(const struct drm_info_list *files,
 					    int count, struct dentry *root,
@@ -176,7 +176,7 @@ static inline void drm_debugfs_add_files
 {}
 
 static inline int drm_debugfs_gpuva_info(struct seq_file *m,
-					 struct drm_gpuva_manager *mgr)
+					 struct drm_gpuvm *gpuvm)
 {
 	return 0;
 }
--- a/include/drm/drm_gpuva_mgr.h
+++ /dev/null
@@ -1,706 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-
-#ifndef __DRM_GPUVA_MGR_H__
-#define __DRM_GPUVA_MGR_H__
-
-/*
- * Copyright (c) 2022 Red Hat.
- *
- * Permission is hereby granted, free of charge, to any person obtaining a
- * copy of this software and associated documentation files (the "Software"),
- * to deal in the Software without restriction, including without limitation
- * the rights to use, copy, modify, merge, publish, distribute, sublicense,
- * and/or sell copies of the Software, and to permit persons to whom the
- * Software is furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
- * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
- * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
- * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
- * OTHER DEALINGS IN THE SOFTWARE.
- */
-
-#include <linux/list.h>
-#include <linux/rbtree.h>
-#include <linux/types.h>
-
-#include <drm/drm_gem.h>
-
-struct drm_gpuva_manager;
-struct drm_gpuva_fn_ops;
-
-/**
- * enum drm_gpuva_flags - flags for struct drm_gpuva
- */
-enum drm_gpuva_flags {
-	/**
-	 * @DRM_GPUVA_INVALIDATED:
-	 *
-	 * Flag indicating that the &drm_gpuva's backing GEM is invalidated.
-	 */
-	DRM_GPUVA_INVALIDATED = (1 << 0),
-
-	/**
-	 * @DRM_GPUVA_SPARSE:
-	 *
-	 * Flag indicating that the &drm_gpuva is a sparse mapping.
-	 */
-	DRM_GPUVA_SPARSE = (1 << 1),
-
-	/**
-	 * @DRM_GPUVA_USERBITS: user defined bits
-	 */
-	DRM_GPUVA_USERBITS = (1 << 2),
-};
-
-/**
- * struct drm_gpuva - structure to track a GPU VA mapping
- *
- * This structure represents a GPU VA mapping and is associated with a
- * &drm_gpuva_manager.
- *
- * Typically, this structure is embedded in bigger driver structures.
- */
-struct drm_gpuva {
-	/**
-	 * @mgr: the &drm_gpuva_manager this object is associated with
-	 */
-	struct drm_gpuva_manager *mgr;
-
-	/**
-	 * @flags: the &drm_gpuva_flags for this mapping
-	 */
-	enum drm_gpuva_flags flags;
-
-	/**
-	 * @va: structure containing the address and range of the &drm_gpuva
-	 */
-	struct {
-		/**
-		 * @addr: the start address
-		 */
-		u64 addr;
-
-		/*
-		 * @range: the range
-		 */
-		u64 range;
-	} va;
-
-	/**
-	 * @gem: structure containing the &drm_gem_object and it's offset
-	 */
-	struct {
-		/**
-		 * @offset: the offset within the &drm_gem_object
-		 */
-		u64 offset;
-
-		/**
-		 * @obj: the mapped &drm_gem_object
-		 */
-		struct drm_gem_object *obj;
-
-		/**
-		 * @entry: the &list_head to attach this object to a &drm_gem_object
-		 */
-		struct list_head entry;
-	} gem;
-
-	/**
-	 * @rb: structure containing data to store &drm_gpuvas in a rb-tree
-	 */
-	struct {
-		/**
-		 * @rb: the rb-tree node
-		 */
-		struct rb_node node;
-
-		/**
-		 * @entry: The &list_head to additionally connect &drm_gpuvas
-		 * in the same order they appear in the interval tree. This is
-		 * useful to keep iterating &drm_gpuvas from a start node found
-		 * through the rb-tree while doing modifications on the rb-tree
-		 * itself.
-		 */
-		struct list_head entry;
-
-		/**
-		 * @__subtree_last: needed by the interval tree, holding last-in-subtree
-		 */
-		u64 __subtree_last;
-	} rb;
-};
-
-int drm_gpuva_insert(struct drm_gpuva_manager *mgr, struct drm_gpuva *va);
-void drm_gpuva_remove(struct drm_gpuva *va);
-
-void drm_gpuva_link(struct drm_gpuva *va);
-void drm_gpuva_unlink(struct drm_gpuva *va);
-
-struct drm_gpuva *drm_gpuva_find(struct drm_gpuva_manager *mgr,
-				 u64 addr, u64 range);
-struct drm_gpuva *drm_gpuva_find_first(struct drm_gpuva_manager *mgr,
-				       u64 addr, u64 range);
-struct drm_gpuva *drm_gpuva_find_prev(struct drm_gpuva_manager *mgr, u64 start);
-struct drm_gpuva *drm_gpuva_find_next(struct drm_gpuva_manager *mgr, u64 end);
-
-bool drm_gpuva_interval_empty(struct drm_gpuva_manager *mgr, u64 addr, u64 range);
-
-static inline void drm_gpuva_init(struct drm_gpuva *va, u64 addr, u64 range,
-				  struct drm_gem_object *obj, u64 offset)
-{
-	va->va.addr = addr;
-	va->va.range = range;
-	va->gem.obj = obj;
-	va->gem.offset = offset;
-}
-
-/**
- * drm_gpuva_invalidate() - sets whether the backing GEM of this &drm_gpuva is
- * invalidated
- * @va: the &drm_gpuva to set the invalidate flag for
- * @invalidate: indicates whether the &drm_gpuva is invalidated
- */
-static inline void drm_gpuva_invalidate(struct drm_gpuva *va, bool invalidate)
-{
-	if (invalidate)
-		va->flags |= DRM_GPUVA_INVALIDATED;
-	else
-		va->flags &= ~DRM_GPUVA_INVALIDATED;
-}
-
-/**
- * drm_gpuva_invalidated() - indicates whether the backing BO of this &drm_gpuva
- * is invalidated
- * @va: the &drm_gpuva to check
- */
-static inline bool drm_gpuva_invalidated(struct drm_gpuva *va)
-{
-	return va->flags & DRM_GPUVA_INVALIDATED;
-}
-
-/**
- * struct drm_gpuva_manager - DRM GPU VA Manager
- *
- * The DRM GPU VA Manager keeps track of a GPU's virtual address space by using
- * &maple_tree structures. Typically, this structure is embedded in bigger
- * driver structures.
- *
- * Drivers can pass addresses and ranges in an arbitrary unit, e.g. bytes or
- * pages.
- *
- * There should be one manager instance per GPU virtual address space.
- */
-struct drm_gpuva_manager {
-	/**
-	 * @name: the name of the DRM GPU VA space
-	 */
-	const char *name;
-
-	/**
-	 * @mm_start: start of the VA space
-	 */
-	u64 mm_start;
-
-	/**
-	 * @mm_range: length of the VA space
-	 */
-	u64 mm_range;
-
-	/**
-	 * @rb: structures to track &drm_gpuva entries
-	 */
-	struct {
-		/**
-		 * @tree: the rb-tree to track GPU VA mappings
-		 */
-		struct rb_root_cached tree;
-
-		/**
-		 * @list: the &list_head to track GPU VA mappings
-		 */
-		struct list_head list;
-	} rb;
-
-	/**
-	 * @kernel_alloc_node:
-	 *
-	 * &drm_gpuva representing the address space cutout reserved for
-	 * the kernel
-	 */
-	struct drm_gpuva kernel_alloc_node;
-
-	/**
-	 * @ops: &drm_gpuva_fn_ops providing the split/merge steps to drivers
-	 */
-	const struct drm_gpuva_fn_ops *ops;
-};
-
-void drm_gpuva_manager_init(struct drm_gpuva_manager *mgr,
-			    const char *name,
-			    u64 start_offset, u64 range,
-			    u64 reserve_offset, u64 reserve_range,
-			    const struct drm_gpuva_fn_ops *ops);
-void drm_gpuva_manager_destroy(struct drm_gpuva_manager *mgr);
-
-static inline struct drm_gpuva *
-__drm_gpuva_next(struct drm_gpuva *va)
-{
-	if (va && !list_is_last(&va->rb.entry, &va->mgr->rb.list))
-		return list_next_entry(va, rb.entry);
-
-	return NULL;
-}
-
-/**
- * drm_gpuva_for_each_va_range() - iterate over a range of &drm_gpuvas
- * @va__: &drm_gpuva structure to assign to in each iteration step
- * @mgr__: &drm_gpuva_manager to walk over
- * @start__: starting offset, the first gpuva will overlap this
- * @end__: ending offset, the last gpuva will start before this (but may
- * overlap)
- *
- * This iterator walks over all &drm_gpuvas in the &drm_gpuva_manager that lie
- * between @start__ and @end__. It is implemented similarly to list_for_each(),
- * but is using the &drm_gpuva_manager's internal interval tree to accelerate
- * the search for the starting &drm_gpuva, and hence isn't safe against removal
- * of elements. It assumes that @end__ is within (or is the upper limit of) the
- * &drm_gpuva_manager. This iterator does not skip over the &drm_gpuva_manager's
- * @kernel_alloc_node.
- */
-#define drm_gpuva_for_each_va_range(va__, mgr__, start__, end__) \
-	for (va__ = drm_gpuva_find_first((mgr__), (start__), (end__) - (start__)); \
-	     va__ && (va__->va.addr < (end__)); \
-	     va__ = __drm_gpuva_next(va__))
-
-/**
- * drm_gpuva_for_each_va_range_safe() - safely iterate over a range of
- * &drm_gpuvas
- * @va__: &drm_gpuva to assign to in each iteration step
- * @next__: another &drm_gpuva to use as temporary storage
- * @mgr__: &drm_gpuva_manager to walk over
- * @start__: starting offset, the first gpuva will overlap this
- * @end__: ending offset, the last gpuva will start before this (but may
- * overlap)
- *
- * This iterator walks over all &drm_gpuvas in the &drm_gpuva_manager that lie
- * between @start__ and @end__. It is implemented similarly to
- * list_for_each_safe(), but is using the &drm_gpuva_manager's internal interval
- * tree to accelerate the search for the starting &drm_gpuva, and hence is safe
- * against removal of elements. It assumes that @end__ is within (or is the
- * upper limit of) the &drm_gpuva_manager. This iterator does not skip over the
- * &drm_gpuva_manager's @kernel_alloc_node.
- */
-#define drm_gpuva_for_each_va_range_safe(va__, next__, mgr__, start__, end__) \
-	for (va__ = drm_gpuva_find_first((mgr__), (start__), (end__) - (start__)), \
-	     next__ = __drm_gpuva_next(va__); \
-	     va__ && (va__->va.addr < (end__)); \
-	     va__ = next__, next__ = __drm_gpuva_next(va__))
-
-/**
- * drm_gpuva_for_each_va() - iterate over all &drm_gpuvas
- * @va__: &drm_gpuva to assign to in each iteration step
- * @mgr__: &drm_gpuva_manager to walk over
- *
- * This iterator walks over all &drm_gpuva structures associated with the given
- * &drm_gpuva_manager.
- */
-#define drm_gpuva_for_each_va(va__, mgr__) \
-	list_for_each_entry(va__, &(mgr__)->rb.list, rb.entry)
-
-/**
- * drm_gpuva_for_each_va_safe() - safely iterate over all &drm_gpuvas
- * @va__: &drm_gpuva to assign to in each iteration step
- * @next__: another &drm_gpuva to use as temporary storage
- * @mgr__: &drm_gpuva_manager to walk over
- *
- * This iterator walks over all &drm_gpuva structures associated with the given
- * &drm_gpuva_manager. It is implemented with list_for_each_entry_safe(), and
- * hence safe against the removal of elements.
- */
-#define drm_gpuva_for_each_va_safe(va__, next__, mgr__) \
-	list_for_each_entry_safe(va__, next__, &(mgr__)->rb.list, rb.entry)
-
-/**
- * enum drm_gpuva_op_type - GPU VA operation type
- *
- * Operations to alter the GPU VA mappings tracked by the &drm_gpuva_manager.
- */
-enum drm_gpuva_op_type {
-	/**
-	 * @DRM_GPUVA_OP_MAP: the map op type
-	 */
-	DRM_GPUVA_OP_MAP,
-
-	/**
-	 * @DRM_GPUVA_OP_REMAP: the remap op type
-	 */
-	DRM_GPUVA_OP_REMAP,
-
-	/**
-	 * @DRM_GPUVA_OP_UNMAP: the unmap op type
-	 */
-	DRM_GPUVA_OP_UNMAP,
-
-	/**
-	 * @DRM_GPUVA_OP_PREFETCH: the prefetch op type
-	 */
-	DRM_GPUVA_OP_PREFETCH,
-};
-
-/**
- * struct drm_gpuva_op_map - GPU VA map operation
- *
- * This structure represents a single map operation generated by the
- * DRM GPU VA manager.
- */
-struct drm_gpuva_op_map {
-	/**
-	 * @va: structure containing address and range of a map
-	 * operation
-	 */
-	struct {
-		/**
-		 * @addr: the base address of the new mapping
-		 */
-		u64 addr;
-
-		/**
-		 * @range: the range of the new mapping
-		 */
-		u64 range;
-	} va;
-
-	/**
-	 * @gem: structure containing the &drm_gem_object and it's offset
-	 */
-	struct {
-		/**
-		 * @offset: the offset within the &drm_gem_object
-		 */
-		u64 offset;
-
-		/**
-		 * @obj: the &drm_gem_object to map
-		 */
-		struct drm_gem_object *obj;
-	} gem;
-};
-
-/**
- * struct drm_gpuva_op_unmap - GPU VA unmap operation
- *
- * This structure represents a single unmap operation generated by the
- * DRM GPU VA manager.
- */
-struct drm_gpuva_op_unmap {
-	/**
-	 * @va: the &drm_gpuva to unmap
-	 */
-	struct drm_gpuva *va;
-
-	/**
-	 * @keep:
-	 *
-	 * Indicates whether this &drm_gpuva is physically contiguous with the
-	 * original mapping request.
-	 *
-	 * Optionally, if &keep is set, drivers may keep the actual page table
-	 * mappings for this &drm_gpuva, adding the missing page table entries
-	 * only and update the &drm_gpuva_manager accordingly.
-	 */
-	bool keep;
-};
-
-/**
- * struct drm_gpuva_op_remap - GPU VA remap operation
- *
- * This represents a single remap operation generated by the DRM GPU VA manager.
- *
- * A remap operation is generated when an existing GPU VA mmapping is split up
- * by inserting a new GPU VA mapping or by partially unmapping existent
- * mapping(s), hence it consists of a maximum of two map and one unmap
- * operation.
- *
- * The @unmap operation takes care of removing the original existing mapping.
- * @prev is used to remap the preceding part, @next the subsequent part.
- *
- * If either a new mapping's start address is aligned with the start address
- * of the old mapping or the new mapping's end address is aligned with the
- * end address of the old mapping, either @prev or @next is NULL.
- *
- * Note, the reason for a dedicated remap operation, rather than arbitrary
- * unmap and map operations, is to give drivers the chance of extracting driver
- * specific data for creating the new mappings from the unmap operations's
- * &drm_gpuva structure which typically is embedded in larger driver specific
- * structures.
- */
-struct drm_gpuva_op_remap {
-	/**
-	 * @prev: the preceding part of a split mapping
-	 */
-	struct drm_gpuva_op_map *prev;
-
-	/**
-	 * @next: the subsequent part of a split mapping
-	 */
-	struct drm_gpuva_op_map *next;
-
-	/**
-	 * @unmap: the unmap operation for the original existing mapping
-	 */
-	struct drm_gpuva_op_unmap *unmap;
-};
-
-/**
- * struct drm_gpuva_op_prefetch - GPU VA prefetch operation
- *
- * This structure represents a single prefetch operation generated by the
- * DRM GPU VA manager.
- */
-struct drm_gpuva_op_prefetch {
-	/**
-	 * @va: the &drm_gpuva to prefetch
-	 */
-	struct drm_gpuva *va;
-};
-
-/**
- * struct drm_gpuva_op - GPU VA operation
- *
- * This structure represents a single generic operation.
- *
- * The particular type of the operation is defined by @op.
- */
-struct drm_gpuva_op {
-	/**
-	 * @entry:
-	 *
-	 * The &list_head used to distribute instances of this struct within
-	 * &drm_gpuva_ops.
-	 */
-	struct list_head entry;
-
-	/**
-	 * @op: the type of the operation
-	 */
-	enum drm_gpuva_op_type op;
-
-	union {
-		/**
-		 * @map: the map operation
-		 */
-		struct drm_gpuva_op_map map;
-
-		/**
-		 * @remap: the remap operation
-		 */
-		struct drm_gpuva_op_remap remap;
-
-		/**
-		 * @unmap: the unmap operation
-		 */
-		struct drm_gpuva_op_unmap unmap;
-
-		/**
-		 * @prefetch: the prefetch operation
-		 */
-		struct drm_gpuva_op_prefetch prefetch;
-	};
-};
-
-/**
- * struct drm_gpuva_ops - wraps a list of &drm_gpuva_op
- */
-struct drm_gpuva_ops {
-	/**
-	 * @list: the &list_head
-	 */
-	struct list_head list;
-};
-
-/**
- * drm_gpuva_for_each_op() - iterator to walk over &drm_gpuva_ops
- * @op: &drm_gpuva_op to assign in each iteration step
- * @ops: &drm_gpuva_ops to walk
- *
- * This iterator walks over all ops within a given list of operations.
- */
-#define drm_gpuva_for_each_op(op, ops) list_for_each_entry(op, &(ops)->list, entry)
-
-/**
- * drm_gpuva_for_each_op_safe() - iterator to safely walk over &drm_gpuva_ops
- * @op: &drm_gpuva_op to assign in each iteration step
- * @next: &next &drm_gpuva_op to store the next step
- * @ops: &drm_gpuva_ops to walk
- *
- * This iterator walks over all ops within a given list of operations. It is
- * implemented with list_for_each_safe(), so save against removal of elements.
- */
-#define drm_gpuva_for_each_op_safe(op, next, ops) \
-	list_for_each_entry_safe(op, next, &(ops)->list, entry)
-
-/**
- * drm_gpuva_for_each_op_from_reverse() - iterate backwards from the given point
- * @op: &drm_gpuva_op to assign in each iteration step
- * @ops: &drm_gpuva_ops to walk
- *
- * This iterator walks over all ops within a given list of operations beginning
- * from the given operation in reverse order.
- */
-#define drm_gpuva_for_each_op_from_reverse(op, ops) \
-	list_for_each_entry_from_reverse(op, &(ops)->list, entry)
-
-/**
- * drm_gpuva_first_op() - returns the first &drm_gpuva_op from &drm_gpuva_ops
- * @ops: the &drm_gpuva_ops to get the fist &drm_gpuva_op from
- */
-#define drm_gpuva_first_op(ops) \
-	list_first_entry(&(ops)->list, struct drm_gpuva_op, entry)
-
-/**
- * drm_gpuva_last_op() - returns the last &drm_gpuva_op from &drm_gpuva_ops
- * @ops: the &drm_gpuva_ops to get the last &drm_gpuva_op from
- */
-#define drm_gpuva_last_op(ops) \
-	list_last_entry(&(ops)->list, struct drm_gpuva_op, entry)
-
-/**
- * drm_gpuva_prev_op() - previous &drm_gpuva_op in the list
- * @op: the current &drm_gpuva_op
- */
-#define drm_gpuva_prev_op(op) list_prev_entry(op, entry)
-
-/**
- * drm_gpuva_next_op() - next &drm_gpuva_op in the list
- * @op: the current &drm_gpuva_op
- */
-#define drm_gpuva_next_op(op) list_next_entry(op, entry)
-
-struct drm_gpuva_ops *
-drm_gpuva_sm_map_ops_create(struct drm_gpuva_manager *mgr,
-			    u64 addr, u64 range,
-			    struct drm_gem_object *obj, u64 offset);
-struct drm_gpuva_ops *
-drm_gpuva_sm_unmap_ops_create(struct drm_gpuva_manager *mgr,
-			      u64 addr, u64 range);
-
-struct drm_gpuva_ops *
-drm_gpuva_prefetch_ops_create(struct drm_gpuva_manager *mgr,
-				 u64 addr, u64 range);
-
-struct drm_gpuva_ops *
-drm_gpuva_gem_unmap_ops_create(struct drm_gpuva_manager *mgr,
-			       struct drm_gem_object *obj);
-
-void drm_gpuva_ops_free(struct drm_gpuva_manager *mgr,
-			struct drm_gpuva_ops *ops);
-
-static inline void drm_gpuva_init_from_op(struct drm_gpuva *va,
-					  struct drm_gpuva_op_map *op)
-{
-	drm_gpuva_init(va, op->va.addr, op->va.range,
-		       op->gem.obj, op->gem.offset);
-}
-
-/**
- * struct drm_gpuva_fn_ops - callbacks for split/merge steps
- *
- * This structure defines the callbacks used by &drm_gpuva_sm_map and
- * &drm_gpuva_sm_unmap to provide the split/merge steps for map and unmap
- * operations to drivers.
- */
-struct drm_gpuva_fn_ops {
-	/**
-	 * @op_alloc: called when the &drm_gpuva_manager allocates
-	 * a struct drm_gpuva_op
-	 *
-	 * Some drivers may want to embed struct drm_gpuva_op into driver
-	 * specific structures. By implementing this callback drivers can
-	 * allocate memory accordingly.
-	 *
-	 * This callback is optional.
-	 */
-	struct drm_gpuva_op *(*op_alloc)(void);
-
-	/**
-	 * @op_free: called when the &drm_gpuva_manager frees a
-	 * struct drm_gpuva_op
-	 *
-	 * Some drivers may want to embed struct drm_gpuva_op into driver
-	 * specific structures. By implementing this callback drivers can
-	 * free the previously allocated memory accordingly.
-	 *
-	 * This callback is optional.
-	 */
-	void (*op_free)(struct drm_gpuva_op *op);
-
-	/**
-	 * @sm_step_map: called from &drm_gpuva_sm_map to finally insert the
-	 * mapping once all previous steps were completed
-	 *
-	 * The &priv pointer matches the one the driver passed to
-	 * &drm_gpuva_sm_map or &drm_gpuva_sm_unmap, respectively.
-	 *
-	 * Can be NULL if &drm_gpuva_sm_map is used.
-	 */
-	int (*sm_step_map)(struct drm_gpuva_op *op, void *priv);
-
-	/**
-	 * @sm_step_remap: called from &drm_gpuva_sm_map and
-	 * &drm_gpuva_sm_unmap to split up an existent mapping
-	 *
-	 * This callback is called when existent mapping needs to be split up.
-	 * This is the case when either a newly requested mapping overlaps or
-	 * is enclosed by an existent mapping or a partial unmap of an existent
-	 * mapping is requested.
-	 *
-	 * The &priv pointer matches the one the driver passed to
-	 * &drm_gpuva_sm_map or &drm_gpuva_sm_unmap, respectively.
-	 *
-	 * Can be NULL if neither &drm_gpuva_sm_map nor &drm_gpuva_sm_unmap is
-	 * used.
-	 */
-	int (*sm_step_remap)(struct drm_gpuva_op *op, void *priv);
-
-	/**
-	 * @sm_step_unmap: called from &drm_gpuva_sm_map and
-	 * &drm_gpuva_sm_unmap to unmap an existent mapping
-	 *
-	 * This callback is called when existent mapping needs to be unmapped.
-	 * This is the case when either a newly requested mapping encloses an
-	 * existent mapping or an unmap of an existent mapping is requested.
-	 *
-	 * The &priv pointer matches the one the driver passed to
-	 * &drm_gpuva_sm_map or &drm_gpuva_sm_unmap, respectively.
-	 *
-	 * Can be NULL if neither &drm_gpuva_sm_map nor &drm_gpuva_sm_unmap is
-	 * used.
-	 */
-	int (*sm_step_unmap)(struct drm_gpuva_op *op, void *priv);
-};
-
-int drm_gpuva_sm_map(struct drm_gpuva_manager *mgr, void *priv,
-		     u64 addr, u64 range,
-		     struct drm_gem_object *obj, u64 offset);
-
-int drm_gpuva_sm_unmap(struct drm_gpuva_manager *mgr, void *priv,
-		       u64 addr, u64 range);
-
-void drm_gpuva_map(struct drm_gpuva_manager *mgr,
-		   struct drm_gpuva *va,
-		   struct drm_gpuva_op_map *op);
-
-void drm_gpuva_remap(struct drm_gpuva *prev,
-		     struct drm_gpuva *next,
-		     struct drm_gpuva_op_remap *op);
-
-void drm_gpuva_unmap(struct drm_gpuva_op_unmap *op);
-
-#endif /* __DRM_GPUVA_MGR_H__ */
--- /dev/null
+++ b/include/drm/drm_gpuvm.h
@@ -0,0 +1,705 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __DRM_GPUVM_H__
+#define __DRM_GPUVM_H__
+
+/*
+ * Copyright (c) 2022 Red Hat.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <linux/list.h>
+#include <linux/rbtree.h>
+#include <linux/types.h>
+
+#include <drm/drm_gem.h>
+
+struct drm_gpuvm;
+struct drm_gpuvm_ops;
+
+/**
+ * enum drm_gpuva_flags - flags for struct drm_gpuva
+ */
+enum drm_gpuva_flags {
+	/**
+	 * @DRM_GPUVA_INVALIDATED:
+	 *
+	 * Flag indicating that the &drm_gpuva's backing GEM is invalidated.
+	 */
+	DRM_GPUVA_INVALIDATED = (1 << 0),
+
+	/**
+	 * @DRM_GPUVA_SPARSE:
+	 *
+	 * Flag indicating that the &drm_gpuva is a sparse mapping.
+	 */
+	DRM_GPUVA_SPARSE = (1 << 1),
+
+	/**
+	 * @DRM_GPUVA_USERBITS: user defined bits
+	 */
+	DRM_GPUVA_USERBITS = (1 << 2),
+};
+
+/**
+ * struct drm_gpuva - structure to track a GPU VA mapping
+ *
+ * This structure represents a GPU VA mapping and is associated with a
+ * &drm_gpuvm.
+ *
+ * Typically, this structure is embedded in bigger driver structures.
+ */
+struct drm_gpuva {
+	/**
+	 * @vm: the &drm_gpuvm this object is associated with
+	 */
+	struct drm_gpuvm *vm;
+
+	/**
+	 * @flags: the &drm_gpuva_flags for this mapping
+	 */
+	enum drm_gpuva_flags flags;
+
+	/**
+	 * @va: structure containing the address and range of the &drm_gpuva
+	 */
+	struct {
+		/**
+		 * @addr: the start address
+		 */
+		u64 addr;
+
+		/*
+		 * @range: the range
+		 */
+		u64 range;
+	} va;
+
+	/**
+	 * @gem: structure containing the &drm_gem_object and it's offset
+	 */
+	struct {
+		/**
+		 * @offset: the offset within the &drm_gem_object
+		 */
+		u64 offset;
+
+		/**
+		 * @obj: the mapped &drm_gem_object
+		 */
+		struct drm_gem_object *obj;
+
+		/**
+		 * @entry: the &list_head to attach this object to a &drm_gem_object
+		 */
+		struct list_head entry;
+	} gem;
+
+	/**
+	 * @rb: structure containing data to store &drm_gpuvas in a rb-tree
+	 */
+	struct {
+		/**
+		 * @rb: the rb-tree node
+		 */
+		struct rb_node node;
+
+		/**
+		 * @entry: The &list_head to additionally connect &drm_gpuvas
+		 * in the same order they appear in the interval tree. This is
+		 * useful to keep iterating &drm_gpuvas from a start node found
+		 * through the rb-tree while doing modifications on the rb-tree
+		 * itself.
+		 */
+		struct list_head entry;
+
+		/**
+		 * @__subtree_last: needed by the interval tree, holding last-in-subtree
+		 */
+		u64 __subtree_last;
+	} rb;
+};
+
+int drm_gpuva_insert(struct drm_gpuvm *gpuvm, struct drm_gpuva *va);
+void drm_gpuva_remove(struct drm_gpuva *va);
+
+void drm_gpuva_link(struct drm_gpuva *va);
+void drm_gpuva_unlink(struct drm_gpuva *va);
+
+struct drm_gpuva *drm_gpuva_find(struct drm_gpuvm *gpuvm,
+				 u64 addr, u64 range);
+struct drm_gpuva *drm_gpuva_find_first(struct drm_gpuvm *gpuvm,
+				       u64 addr, u64 range);
+struct drm_gpuva *drm_gpuva_find_prev(struct drm_gpuvm *gpuvm, u64 start);
+struct drm_gpuva *drm_gpuva_find_next(struct drm_gpuvm *gpuvm, u64 end);
+
+static inline void drm_gpuva_init(struct drm_gpuva *va, u64 addr, u64 range,
+				  struct drm_gem_object *obj, u64 offset)
+{
+	va->va.addr = addr;
+	va->va.range = range;
+	va->gem.obj = obj;
+	va->gem.offset = offset;
+}
+
+/**
+ * drm_gpuva_invalidate() - sets whether the backing GEM of this &drm_gpuva is
+ * invalidated
+ * @va: the &drm_gpuva to set the invalidate flag for
+ * @invalidate: indicates whether the &drm_gpuva is invalidated
+ */
+static inline void drm_gpuva_invalidate(struct drm_gpuva *va, bool invalidate)
+{
+	if (invalidate)
+		va->flags |= DRM_GPUVA_INVALIDATED;
+	else
+		va->flags &= ~DRM_GPUVA_INVALIDATED;
+}
+
+/**
+ * drm_gpuva_invalidated() - indicates whether the backing BO of this &drm_gpuva
+ * is invalidated
+ * @va: the &drm_gpuva to check
+ */
+static inline bool drm_gpuva_invalidated(struct drm_gpuva *va)
+{
+	return va->flags & DRM_GPUVA_INVALIDATED;
+}
+
+/**
+ * struct drm_gpuvm - DRM GPU VA Manager
+ *
+ * The DRM GPU VA Manager keeps track of a GPU's virtual address space by using
+ * &maple_tree structures. Typically, this structure is embedded in bigger
+ * driver structures.
+ *
+ * Drivers can pass addresses and ranges in an arbitrary unit, e.g. bytes or
+ * pages.
+ *
+ * There should be one manager instance per GPU virtual address space.
+ */
+struct drm_gpuvm {
+	/**
+	 * @name: the name of the DRM GPU VA space
+	 */
+	const char *name;
+
+	/**
+	 * @mm_start: start of the VA space
+	 */
+	u64 mm_start;
+
+	/**
+	 * @mm_range: length of the VA space
+	 */
+	u64 mm_range;
+
+	/**
+	 * @rb: structures to track &drm_gpuva entries
+	 */
+	struct {
+		/**
+		 * @tree: the rb-tree to track GPU VA mappings
+		 */
+		struct rb_root_cached tree;
+
+		/**
+		 * @list: the &list_head to track GPU VA mappings
+		 */
+		struct list_head list;
+	} rb;
+
+	/**
+	 * @kernel_alloc_node:
+	 *
+	 * &drm_gpuva representing the address space cutout reserved for
+	 * the kernel
+	 */
+	struct drm_gpuva kernel_alloc_node;
+
+	/**
+	 * @ops: &drm_gpuvm_ops providing the split/merge steps to drivers
+	 */
+	const struct drm_gpuvm_ops *ops;
+};
+
+void drm_gpuvm_init(struct drm_gpuvm *gpuvm, const char *name,
+		    u64 start_offset, u64 range,
+		    u64 reserve_offset, u64 reserve_range,
+		    const struct drm_gpuvm_ops *ops);
+void drm_gpuvm_destroy(struct drm_gpuvm *gpuvm);
+
+bool drm_gpuvm_interval_empty(struct drm_gpuvm *gpuvm, u64 addr, u64 range);
+
+static inline struct drm_gpuva *
+__drm_gpuva_next(struct drm_gpuva *va)
+{
+	if (va && !list_is_last(&va->rb.entry, &va->vm->rb.list))
+		return list_next_entry(va, rb.entry);
+
+	return NULL;
+}
+
+/**
+ * drm_gpuvm_for_each_va_range() - iterate over a range of &drm_gpuvas
+ * @va__: &drm_gpuva structure to assign to in each iteration step
+ * @gpuvm__: &drm_gpuvm to walk over
+ * @start__: starting offset, the first gpuva will overlap this
+ * @end__: ending offset, the last gpuva will start before this (but may
+ * overlap)
+ *
+ * This iterator walks over all &drm_gpuvas in the &drm_gpuvm that lie
+ * between @start__ and @end__. It is implemented similarly to list_for_each(),
+ * but is using the &drm_gpuvm's internal interval tree to accelerate
+ * the search for the starting &drm_gpuva, and hence isn't safe against removal
+ * of elements. It assumes that @end__ is within (or is the upper limit of) the
+ * &drm_gpuvm. This iterator does not skip over the &drm_gpuvm's
+ * @kernel_alloc_node.
+ */
+#define drm_gpuvm_for_each_va_range(va__, gpuvm__, start__, end__) \
+	for (va__ = drm_gpuva_find_first((gpuvm__), (start__), (end__) - (start__)); \
+	     va__ && (va__->va.addr < (end__)); \
+	     va__ = __drm_gpuva_next(va__))
+
+/**
+ * drm_gpuvm_for_each_va_range_safe() - safely iterate over a range of
+ * &drm_gpuvas
+ * @va__: &drm_gpuva to assign to in each iteration step
+ * @next__: another &drm_gpuva to use as temporary storage
+ * @gpuvm__: &drm_gpuvm to walk over
+ * @start__: starting offset, the first gpuva will overlap this
+ * @end__: ending offset, the last gpuva will start before this (but may
+ * overlap)
+ *
+ * This iterator walks over all &drm_gpuvas in the &drm_gpuvm that lie
+ * between @start__ and @end__. It is implemented similarly to
+ * list_for_each_safe(), but is using the &drm_gpuvm's internal interval
+ * tree to accelerate the search for the starting &drm_gpuva, and hence is safe
+ * against removal of elements. It assumes that @end__ is within (or is the
+ * upper limit of) the &drm_gpuvm. This iterator does not skip over the
+ * &drm_gpuvm's @kernel_alloc_node.
+ */
+#define drm_gpuvm_for_each_va_range_safe(va__, next__, gpuvm__, start__, end__) \
+	for (va__ = drm_gpuva_find_first((gpuvm__), (start__), (end__) - (start__)), \
+	     next__ = __drm_gpuva_next(va__); \
+	     va__ && (va__->va.addr < (end__)); \
+	     va__ = next__, next__ = __drm_gpuva_next(va__))
+
+/**
+ * drm_gpuvm_for_each_va() - iterate over all &drm_gpuvas
+ * @va__: &drm_gpuva to assign to in each iteration step
+ * @gpuvm__: &drm_gpuvm to walk over
+ *
+ * This iterator walks over all &drm_gpuva structures associated with the given
+ * &drm_gpuvm.
+ */
+#define drm_gpuvm_for_each_va(va__, gpuvm__) \
+	list_for_each_entry(va__, &(gpuvm__)->rb.list, rb.entry)
+
+/**
+ * drm_gpuvm_for_each_va_safe() - safely iterate over all &drm_gpuvas
+ * @va__: &drm_gpuva to assign to in each iteration step
+ * @next__: another &drm_gpuva to use as temporary storage
+ * @gpuvm__: &drm_gpuvm to walk over
+ *
+ * This iterator walks over all &drm_gpuva structures associated with the given
+ * &drm_gpuvm. It is implemented with list_for_each_entry_safe(), and
+ * hence safe against the removal of elements.
+ */
+#define drm_gpuvm_for_each_va_safe(va__, next__, gpuvm__) \
+	list_for_each_entry_safe(va__, next__, &(gpuvm__)->rb.list, rb.entry)
+
+/**
+ * enum drm_gpuva_op_type - GPU VA operation type
+ *
+ * Operations to alter the GPU VA mappings tracked by the &drm_gpuvm.
+ */
+enum drm_gpuva_op_type {
+	/**
+	 * @DRM_GPUVA_OP_MAP: the map op type
+	 */
+	DRM_GPUVA_OP_MAP,
+
+	/**
+	 * @DRM_GPUVA_OP_REMAP: the remap op type
+	 */
+	DRM_GPUVA_OP_REMAP,
+
+	/**
+	 * @DRM_GPUVA_OP_UNMAP: the unmap op type
+	 */
+	DRM_GPUVA_OP_UNMAP,
+
+	/**
+	 * @DRM_GPUVA_OP_PREFETCH: the prefetch op type
+	 */
+	DRM_GPUVA_OP_PREFETCH,
+};
+
+/**
+ * struct drm_gpuva_op_map - GPU VA map operation
+ *
+ * This structure represents a single map operation generated by the
+ * DRM GPU VA manager.
+ */
+struct drm_gpuva_op_map {
+	/**
+	 * @va: structure containing address and range of a map
+	 * operation
+	 */
+	struct {
+		/**
+		 * @addr: the base address of the new mapping
+		 */
+		u64 addr;
+
+		/**
+		 * @range: the range of the new mapping
+		 */
+		u64 range;
+	} va;
+
+	/**
+	 * @gem: structure containing the &drm_gem_object and it's offset
+	 */
+	struct {
+		/**
+		 * @offset: the offset within the &drm_gem_object
+		 */
+		u64 offset;
+
+		/**
+		 * @obj: the &drm_gem_object to map
+		 */
+		struct drm_gem_object *obj;
+	} gem;
+};
+
+/**
+ * struct drm_gpuva_op_unmap - GPU VA unmap operation
+ *
+ * This structure represents a single unmap operation generated by the
+ * DRM GPU VA manager.
+ */
+struct drm_gpuva_op_unmap {
+	/**
+	 * @va: the &drm_gpuva to unmap
+	 */
+	struct drm_gpuva *va;
+
+	/**
+	 * @keep:
+	 *
+	 * Indicates whether this &drm_gpuva is physically contiguous with the
+	 * original mapping request.
+	 *
+	 * Optionally, if &keep is set, drivers may keep the actual page table
+	 * mappings for this &drm_gpuva, adding the missing page table entries
+	 * only and update the &drm_gpuvm accordingly.
+	 */
+	bool keep;
+};
+
+/**
+ * struct drm_gpuva_op_remap - GPU VA remap operation
+ *
+ * This represents a single remap operation generated by the DRM GPU VA manager.
+ *
+ * A remap operation is generated when an existing GPU VA mmapping is split up
+ * by inserting a new GPU VA mapping or by partially unmapping existent
+ * mapping(s), hence it consists of a maximum of two map and one unmap
+ * operation.
+ *
+ * The @unmap operation takes care of removing the original existing mapping.
+ * @prev is used to remap the preceding part, @next the subsequent part.
+ *
+ * If either a new mapping's start address is aligned with the start address
+ * of the old mapping or the new mapping's end address is aligned with the
+ * end address of the old mapping, either @prev or @next is NULL.
+ *
+ * Note, the reason for a dedicated remap operation, rather than arbitrary
+ * unmap and map operations, is to give drivers the chance of extracting driver
+ * specific data for creating the new mappings from the unmap operations's
+ * &drm_gpuva structure which typically is embedded in larger driver specific
+ * structures.
+ */
+struct drm_gpuva_op_remap {
+	/**
+	 * @prev: the preceding part of a split mapping
+	 */
+	struct drm_gpuva_op_map *prev;
+
+	/**
+	 * @next: the subsequent part of a split mapping
+	 */
+	struct drm_gpuva_op_map *next;
+
+	/**
+	 * @unmap: the unmap operation for the original existing mapping
+	 */
+	struct drm_gpuva_op_unmap *unmap;
+};
+
+/**
+ * struct drm_gpuva_op_prefetch - GPU VA prefetch operation
+ *
+ * This structure represents a single prefetch operation generated by the
+ * DRM GPU VA manager.
+ */
+struct drm_gpuva_op_prefetch {
+	/**
+	 * @va: the &drm_gpuva to prefetch
+	 */
+	struct drm_gpuva *va;
+};
+
+/**
+ * struct drm_gpuva_op - GPU VA operation
+ *
+ * This structure represents a single generic operation.
+ *
+ * The particular type of the operation is defined by @op.
+ */
+struct drm_gpuva_op {
+	/**
+	 * @entry:
+	 *
+	 * The &list_head used to distribute instances of this struct within
+	 * &drm_gpuva_ops.
+	 */
+	struct list_head entry;
+
+	/**
+	 * @op: the type of the operation
+	 */
+	enum drm_gpuva_op_type op;
+
+	union {
+		/**
+		 * @map: the map operation
+		 */
+		struct drm_gpuva_op_map map;
+
+		/**
+		 * @remap: the remap operation
+		 */
+		struct drm_gpuva_op_remap remap;
+
+		/**
+		 * @unmap: the unmap operation
+		 */
+		struct drm_gpuva_op_unmap unmap;
+
+		/**
+		 * @prefetch: the prefetch operation
+		 */
+		struct drm_gpuva_op_prefetch prefetch;
+	};
+};
+
+/**
+ * struct drm_gpuva_ops - wraps a list of &drm_gpuva_op
+ */
+struct drm_gpuva_ops {
+	/**
+	 * @list: the &list_head
+	 */
+	struct list_head list;
+};
+
+/**
+ * drm_gpuva_for_each_op() - iterator to walk over &drm_gpuva_ops
+ * @op: &drm_gpuva_op to assign in each iteration step
+ * @ops: &drm_gpuva_ops to walk
+ *
+ * This iterator walks over all ops within a given list of operations.
+ */
+#define drm_gpuva_for_each_op(op, ops) list_for_each_entry(op, &(ops)->list, entry)
+
+/**
+ * drm_gpuva_for_each_op_safe() - iterator to safely walk over &drm_gpuva_ops
+ * @op: &drm_gpuva_op to assign in each iteration step
+ * @next: &next &drm_gpuva_op to store the next step
+ * @ops: &drm_gpuva_ops to walk
+ *
+ * This iterator walks over all ops within a given list of operations. It is
+ * implemented with list_for_each_safe(), so save against removal of elements.
+ */
+#define drm_gpuva_for_each_op_safe(op, next, ops) \
+	list_for_each_entry_safe(op, next, &(ops)->list, entry)
+
+/**
+ * drm_gpuva_for_each_op_from_reverse() - iterate backwards from the given point
+ * @op: &drm_gpuva_op to assign in each iteration step
+ * @ops: &drm_gpuva_ops to walk
+ *
+ * This iterator walks over all ops within a given list of operations beginning
+ * from the given operation in reverse order.
+ */
+#define drm_gpuva_for_each_op_from_reverse(op, ops) \
+	list_for_each_entry_from_reverse(op, &(ops)->list, entry)
+
+/**
+ * drm_gpuva_first_op() - returns the first &drm_gpuva_op from &drm_gpuva_ops
+ * @ops: the &drm_gpuva_ops to get the fist &drm_gpuva_op from
+ */
+#define drm_gpuva_first_op(ops) \
+	list_first_entry(&(ops)->list, struct drm_gpuva_op, entry)
+
+/**
+ * drm_gpuva_last_op() - returns the last &drm_gpuva_op from &drm_gpuva_ops
+ * @ops: the &drm_gpuva_ops to get the last &drm_gpuva_op from
+ */
+#define drm_gpuva_last_op(ops) \
+	list_last_entry(&(ops)->list, struct drm_gpuva_op, entry)
+
+/**
+ * drm_gpuva_prev_op() - previous &drm_gpuva_op in the list
+ * @op: the current &drm_gpuva_op
+ */
+#define drm_gpuva_prev_op(op) list_prev_entry(op, entry)
+
+/**
+ * drm_gpuva_next_op() - next &drm_gpuva_op in the list
+ * @op: the current &drm_gpuva_op
+ */
+#define drm_gpuva_next_op(op) list_next_entry(op, entry)
+
+struct drm_gpuva_ops *
+drm_gpuvm_sm_map_ops_create(struct drm_gpuvm *gpuvm,
+			    u64 addr, u64 range,
+			    struct drm_gem_object *obj, u64 offset);
+struct drm_gpuva_ops *
+drm_gpuvm_sm_unmap_ops_create(struct drm_gpuvm *gpuvm,
+			      u64 addr, u64 range);
+
+struct drm_gpuva_ops *
+drm_gpuvm_prefetch_ops_create(struct drm_gpuvm *gpuvm,
+				 u64 addr, u64 range);
+
+struct drm_gpuva_ops *
+drm_gpuvm_gem_unmap_ops_create(struct drm_gpuvm *gpuvm,
+			       struct drm_gem_object *obj);
+
+void drm_gpuva_ops_free(struct drm_gpuvm *gpuvm,
+			struct drm_gpuva_ops *ops);
+
+static inline void drm_gpuva_init_from_op(struct drm_gpuva *va,
+					  struct drm_gpuva_op_map *op)
+{
+	drm_gpuva_init(va, op->va.addr, op->va.range,
+		       op->gem.obj, op->gem.offset);
+}
+
+/**
+ * struct drm_gpuvm_ops - callbacks for split/merge steps
+ *
+ * This structure defines the callbacks used by &drm_gpuvm_sm_map and
+ * &drm_gpuvm_sm_unmap to provide the split/merge steps for map and unmap
+ * operations to drivers.
+ */
+struct drm_gpuvm_ops {
+	/**
+	 * @op_alloc: called when the &drm_gpuvm allocates
+	 * a struct drm_gpuva_op
+	 *
+	 * Some drivers may want to embed struct drm_gpuva_op into driver
+	 * specific structures. By implementing this callback drivers can
+	 * allocate memory accordingly.
+	 *
+	 * This callback is optional.
+	 */
+	struct drm_gpuva_op *(*op_alloc)(void);
+
+	/**
+	 * @op_free: called when the &drm_gpuvm frees a
+	 * struct drm_gpuva_op
+	 *
+	 * Some drivers may want to embed struct drm_gpuva_op into driver
+	 * specific structures. By implementing this callback drivers can
+	 * free the previously allocated memory accordingly.
+	 *
+	 * This callback is optional.
+	 */
+	void (*op_free)(struct drm_gpuva_op *op);
+
+	/**
+	 * @sm_step_map: called from &drm_gpuvm_sm_map to finally insert the
+	 * mapping once all previous steps were completed
+	 *
+	 * The &priv pointer matches the one the driver passed to
+	 * &drm_gpuvm_sm_map or &drm_gpuvm_sm_unmap, respectively.
+	 *
+	 * Can be NULL if &drm_gpuvm_sm_map is used.
+	 */
+	int (*sm_step_map)(struct drm_gpuva_op *op, void *priv);
+
+	/**
+	 * @sm_step_remap: called from &drm_gpuvm_sm_map and
+	 * &drm_gpuvm_sm_unmap to split up an existent mapping
+	 *
+	 * This callback is called when existent mapping needs to be split up.
+	 * This is the case when either a newly requested mapping overlaps or
+	 * is enclosed by an existent mapping or a partial unmap of an existent
+	 * mapping is requested.
+	 *
+	 * The &priv pointer matches the one the driver passed to
+	 * &drm_gpuvm_sm_map or &drm_gpuvm_sm_unmap, respectively.
+	 *
+	 * Can be NULL if neither &drm_gpuvm_sm_map nor &drm_gpuvm_sm_unmap is
+	 * used.
+	 */
+	int (*sm_step_remap)(struct drm_gpuva_op *op, void *priv);
+
+	/**
+	 * @sm_step_unmap: called from &drm_gpuvm_sm_map and
+	 * &drm_gpuvm_sm_unmap to unmap an existent mapping
+	 *
+	 * This callback is called when existent mapping needs to be unmapped.
+	 * This is the case when either a newly requested mapping encloses an
+	 * existent mapping or an unmap of an existent mapping is requested.
+	 *
+	 * The &priv pointer matches the one the driver passed to
+	 * &drm_gpuvm_sm_map or &drm_gpuvm_sm_unmap, respectively.
+	 *
+	 * Can be NULL if neither &drm_gpuvm_sm_map nor &drm_gpuvm_sm_unmap is
+	 * used.
+	 */
+	int (*sm_step_unmap)(struct drm_gpuva_op *op, void *priv);
+};
+
+int drm_gpuvm_sm_map(struct drm_gpuvm *gpuvm, void *priv,
+		     u64 addr, u64 range,
+		     struct drm_gem_object *obj, u64 offset);
+
+int drm_gpuvm_sm_unmap(struct drm_gpuvm *gpuvm, void *priv,
+		       u64 addr, u64 range);
+
+void drm_gpuva_map(struct drm_gpuvm *gpuvm,
+		   struct drm_gpuva *va,
+		   struct drm_gpuva_op_map *op);
+
+void drm_gpuva_remap(struct drm_gpuva *prev,
+		     struct drm_gpuva *next,
+		     struct drm_gpuva_op_remap *op);
+
+void drm_gpuva_unmap(struct drm_gpuva_op_unmap *op);
+
+#endif /* __DRM_GPUVM_H__ */
