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Message-ID: <71bd82c3-0564-8f14-e7d7-e6d55696bd27@redhat.com>
Date: Mon, 6 Feb 2023 14:46:00 +0100
From: Danilo Krummrich <dakr@...hat.com>
To: Christian König <christian.koenig@....com>,
Matthew Brost <matthew.brost@...el.com>
Cc: daniel@...ll.ch, airlied@...hat.com, bskeggs@...hat.com,
jason@...kstrand.net, tzimmermann@...e.de, mripard@...nel.org,
corbet@....net, nouveau@...ts.freedesktop.org,
linux-kernel@...r.kernel.org, dri-devel@...ts.freedesktop.org,
linux-doc@...r.kernel.org
Subject: Re: [PATCH drm-next 03/14] drm: manager to keep track of GPUs VA
mappings
On 2/6/23 14:35, Christian König wrote:
> Am 03.02.23 um 18:37 schrieb Matthew Brost:
>> On Wed, Jan 18, 2023 at 07:12:45AM +0100, Danilo Krummrich wrote:
>>> This adds the infrastructure for a manager implementation to keep track
>>> of GPU virtual address (VA) mappings.
>>>
>>> New UAPIs, motivated by Vulkan sparse memory bindings graphics drivers
>>> start implementing, allow userspace applications to request multiple and
>>> arbitrary GPU VA mappings of buffer objects. The DRM GPU VA manager is
>>> intended to serve the following purposes in this context.
>>>
>>> 1) Provide a dedicated range allocator to track GPU VA allocations and
>>> mappings, making use of the drm_mm range allocator.
>>>
>>> 2) Generically connect GPU VA mappings to their backing buffers, in
>>> particular DRM GEM objects.
>>>
>>> 3) Provide a common implementation to perform more complex mapping
>>> operations on the GPU VA space. In particular splitting and merging
>>> of GPU VA mappings, e.g. for intersecting mapping requests or
>>> partial
>>> unmap requests.
>>>
>> Over the past week I've hacked together a PoC port of Xe to GPUVA [1], so
>> far it seems really promising. 95% of the way to being feature
>> equivalent of the current Xe VM bind implementation and have line of
>> sight to getting sparse bindings implemented on top of GPUVA too. IMO
>> this has basically everything we need for Xe with a few tweaks.
>>
>> I am out until 2/14 but wanted to get my thoughts / suggestions out on
>> the list before I leave.
>>
>> 1. GPUVA post didn't support the way Xe does userptrs - a NULL GEM. I
>> believe with [2], [3], and [4] GPUVA will support NULL GEMs. Also my
>> thinking sparse binds will also have NULL GEMs, more on sparse bindings
>> below.
>>
>> 2. I agree with Christian that drm_mm probably isn't what we want to
>> base the GPUVA implementation on, rather a RB tree or Maple tree has
>> been discussed. The implementation should be fairly easy to tune once we
>> have benchmarks running so not to concerned here as we can figure this
>> out down the line.
>>
>> 3. In Xe we want create xe_vm_op list which inherits from drm_gpuva_op
>> I've done this with a hack [5], I believe when we rebase we can do this
>> with a custom callback to allocate a large op size.
>>
>> 4. I'd like add user bits to drm_gpuva_flags like I do in [6]. This is
>> similar to DMA_FENCE_FLAG_USER_BITS.
>>
>> 5. In Xe we have VM prefetch operation which is needed for our compute
>> UMD with page faults. I'd like add prefetch type of operation like we do
>> in [7].
>>
>> 6. In Xe we have VM unbind all mappings for a GEM IOCTL, I'd like to add
>> support to generate this operation list to GPUVA like we do in [8].
>>
>> 7. I've thought about how Xe will implement sparse mappings (read 0,
>> writes dropped). My current thinking is a sparse mapping will be
>> represented as a drm_gpuva rather than region like in Nouveau. Making
>> regions optional to me seems likes good idea rather than forcing the
>> user of GPUVA code to create 1 large region for the manager as I
>> currently do in the Xe PoC.
>
> From Danilo's explanation I'm now pretty sure that regions won't work
> for Nouveau either.
>
> He seems to use an incorrect assumption about applications not changing
> the sparse mappings behind a VkBuffer while the GPU is using it.
>
> As far as I can see games like Forza won't work with this approach.
>
I appreciate sharing your concerns since they're seriously helping me to
improve things and consider things I missed before. However, I'd prefer
to wait for clarification before distributing them to other sub-threads.
Depending on whether the understanding of where those concerns arise
from turns out to be right or wrong, this might cause confusion for
people not following *all* sub-threads.
>>
>> 8. Personally I'd like the caller to own the locking for GEM drm_gpuva
>> list (drm_gpuva_link_*, drm_gpuva_unlink_* functions). In Xe we almost
>> certainly will have the GEM dma-resv lock when we touch this list so an
>> extra lock here is redundant. Also it kinda goofy that caller owns the
>> for drm_gpuva insertion / removal but not the locking for this list.
>>
>> WRT to Christian thoughts on a common uAPI rules for VM binds, I kinda
>> like that idea but I don't think that is necessary. All of pur uAPI
>> should be close but also the GPUVA implementation should be flexible
>> enough to fit all of our needs and I think for the most part it is.
>
> Maybe I should refine my concerns: A common component for GPUVM mappings
> is a good idea, but we should not expect that to define any driver
> independent UAPI.
>
> If we want to define driver independent UAPI we should do so explicitly.
>
> Christian.
>
>>
>> Let me know what everything thinks about this. It would be great if when
>> I'm back on 2/14 I can rebase the Xe port to GPUVA on another version of
>> the GPUVA code and get sparse binding support implementation. Also I'd
>> like to get GPUVA merged in the Xe repo ASAP as our VM bind code badly
>> needed to be cleaned and this was the push we needed to make this
>> happen.
>>
>> Matt
>>
>> [1] https://gitlab.freedesktop.org/drm/xe/kernel/-/merge_requests/314
>> [2]
>> https://gitlab.freedesktop.org/drm/xe/kernel/-/merge_requests/314/diffs?commit_id=2ae21d7a3f52e5eb2c105ed8ae231471274bdc36
>> [3]
>> https://gitlab.freedesktop.org/drm/xe/kernel/-/merge_requests/314/diffs?commit_id=49fca9f5d96201f5cbd1b19c7ff17eedfac65cdc
>> [4]
>> https://gitlab.freedesktop.org/drm/xe/kernel/-/merge_requests/314/diffs?commit_id=61fa6b1e1f10e791ae82358fa971b04421d53024
>> [5]
>> https://gitlab.freedesktop.org/drm/xe/kernel/-/merge_requests/314/diffs?commit_id=87fc08dcf0840e794b38269fe4c6a95d088d79ec
>> [6]
>> https://gitlab.freedesktop.org/drm/xe/kernel/-/merge_requests/314/diffs?commit_id=a4826c22f6788bc29906ffa263c1cd3c4661fa77
>> [7]
>> https://gitlab.freedesktop.org/drm/xe/kernel/-/merge_requests/314/diffs?commit_id=f008bbb55b213868e52c7b9cda4c1bfb95af6aee
>> [8]
>> https://gitlab.freedesktop.org/drm/xe/kernel/-/merge_requests/314/diffs?commit_id=41f4f71c05d04d2b17d988dd95369b5df2d7f681
>>
>>> Idea-suggested-by: Dave Airlie <airlied@...hat.com>
>>> Signed-off-by: Danilo Krummrich <dakr@...hat.com>
>>> ---
>>> Documentation/gpu/drm-mm.rst | 31 +
>>> drivers/gpu/drm/Makefile | 1 +
>>> drivers/gpu/drm/drm_gem.c | 3 +
>>> drivers/gpu/drm/drm_gpuva_mgr.c | 1323 +++++++++++++++++++++++++++++++
>>> include/drm/drm_drv.h | 6 +
>>> include/drm/drm_gem.h | 75 ++
>>> include/drm/drm_gpuva_mgr.h | 527 ++++++++++++
>>> 7 files changed, 1966 insertions(+)
>>> create mode 100644 drivers/gpu/drm/drm_gpuva_mgr.c
>>> create mode 100644 include/drm/drm_gpuva_mgr.h
>>>
>>> diff --git a/Documentation/gpu/drm-mm.rst b/Documentation/gpu/drm-mm.rst
>>> index a52e6f4117d6..c9f120cfe730 100644
>>> --- a/Documentation/gpu/drm-mm.rst
>>> +++ b/Documentation/gpu/drm-mm.rst
>>> @@ -466,6 +466,37 @@ DRM MM Range Allocator Function References
>>> .. kernel-doc:: drivers/gpu/drm/drm_mm.c
>>> :export:
>>> +DRM GPU VA Manager
>>> +==================
>>> +
>>> +Overview
>>> +--------
>>> +
>>> +.. kernel-doc:: drivers/gpu/drm/drm_gpuva_mgr.c
>>> + :doc: Overview
>>> +
>>> +Split and Merge
>>> +---------------
>>> +
>>> +.. kernel-doc:: drivers/gpu/drm/drm_gpuva_mgr.c
>>> + :doc: Split and Merge
>>> +
>>> +Locking
>>> +-------
>>> +
>>> +.. kernel-doc:: drivers/gpu/drm/drm_gpuva_mgr.c
>>> + :doc: Locking
>>> +
>>> +
>>> +DRM GPU VA Manager Function References
>>> +--------------------------------------
>>> +
>>> +.. kernel-doc:: include/drm/drm_gpuva_mgr.h
>>> + :internal:
>>> +
>>> +.. kernel-doc:: drivers/gpu/drm/drm_gpuva_mgr.c
>>> + :export:
>>> +
>>> DRM Buddy Allocator
>>> ===================
>>> diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
>>> index 4fe190aee584..de2ffca3b6e4 100644
>>> --- a/drivers/gpu/drm/Makefile
>>> +++ b/drivers/gpu/drm/Makefile
>>> @@ -45,6 +45,7 @@ drm-y := \
>>> drm_vblank.o \
>>> drm_vblank_work.o \
>>> drm_vma_manager.o \
>>> + drm_gpuva_mgr.o \
>>> drm_writeback.o
>>> drm-$(CONFIG_DRM_LEGACY) += \
>>> drm_agpsupport.o \
>>> diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
>>> index 59a0bb5ebd85..65115fe88627 100644
>>> --- a/drivers/gpu/drm/drm_gem.c
>>> +++ b/drivers/gpu/drm/drm_gem.c
>>> @@ -164,6 +164,9 @@ void drm_gem_private_object_init(struct
>>> drm_device *dev,
>>> if (!obj->resv)
>>> obj->resv = &obj->_resv;
>>> + if (drm_core_check_feature(dev, DRIVER_GEM_GPUVA))
>>> + drm_gem_gpuva_init(obj);
>>> +
>>> drm_vma_node_reset(&obj->vma_node);
>>> INIT_LIST_HEAD(&obj->lru_node);
>>> }
>>> diff --git a/drivers/gpu/drm/drm_gpuva_mgr.c
>>> b/drivers/gpu/drm/drm_gpuva_mgr.c
>>> new file mode 100644
>>> index 000000000000..e665f642689d
>>> --- /dev/null
>>> +++ b/drivers/gpu/drm/drm_gpuva_mgr.c
>>> @@ -0,0 +1,1323 @@
>>> +// SPDX-License-Identifier: GPL-2.0
>>> +/*
>>> + * 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@...hat.com>
>>> + *
>>> + */
>>> +
>>> +#include <drm/drm_gem.h>
>>> +#include <drm/drm_gpuva_mgr.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 (and a corresponding list
>>> lock) of
>>> + * &drm_gpuva objects representing all existent GPU VA mappings
>>> using this
>>> + * &drm_gem_object as backing buffer.
>>> + *
>>> + * A GPU VA mapping can only be created within a previously allocated
>>> + * &drm_gpuva_region, which represents a reserved portion of the GPU
>>> VA space.
>>> + * GPU VA mappings are not allowed to span over a
>>> &drm_gpuva_region's boundary.
>>> + *
>>> + * GPU VA regions can also be flagged as sparse, which allows
>>> drivers to create
>>> + * sparse mappings for a whole GPU VA region in order to support Vulkan
>>> + * 'Sparse Resources'.
>>> + *
>>> + * The GPU VA manager internally uses the &drm_mm range allocator to
>>> manage the
>>> + * &drm_gpuva mappings and the &drm_gpuva_regions within a GPU's
>>> virtual address
>>> + * space.
>>> + *
>>> + * Besides the GPU VA space regions (&drm_gpuva_region) allocated by
>>> a driver
>>> + * the &drm_gpuva_manager contains a special region 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,
>>> + * struct drm_gpuva_region and struct drm_gpuva within their own driver
>>> + * specific structures, there won't be any memory allocations of
>>> it's own nor
>>> + * memory allocations of &drm_gpuva or &drm_gpuva_region entries.
>>> + */
>>> +
>>> +/**
>>> + * DOC: Split and Merge
>>> + *
>>> + * The DRM GPU VA manager also 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_ops_create() to obtain a list
>>> of map, unmap
>>> + * and remap operations for a given newly requested mapping. This list
>>> + * 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_ops contain an arbitrary
>>> amount of unmap
>>> + * operations, a maximum of two remap operations and a single map
>>> operation.
>>> + * The set of operations can also be empty if no operation is
>>> required, e.g. if
>>> + * the requested mapping already exists in the exact same way.
>>> + *
>>> + * The single map operation, if existent, represents the original
>>> map operation
>>> + * requested by the caller. Please note that this operation might be
>>> altered
>>> + * comparing it with the original map operation, e.g. because it was
>>> merged with
>>> + * an already existent mapping. Hence, drivers must execute this
>>> map operation
>>> + * instead of the original one they passed to
>>> drm_gpuva_sm_map_ops_create().
>>> + *
>>> + * &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.
>>> + *
>>> + * Generally, the DRM GPU VA manager never merges mappings across the
>>> + * boundaries of &drm_gpuva_regions. This is the case since merging
>>> between
>>> + * GPU VA regions would result into unmap and map operations to be
>>> issued for
>>> + * both regions involved although the original mapping request was
>>> referred to
>>> + * one specific GPU VA region only. Since the other GPU VA region,
>>> the one not
>>> + * explicitly requested to be altered, might be in use by the GPU,
>>> we are not
>>> + * allowed to issue any map/unmap operations for this region.
>>> + *
>>> + * Note that before calling drm_gpuva_sm_map_ops_create() 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 fully
>>> + * processed or completely 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.
>>> + *
>>> + * Analogue to drm_gpuva_sm_map_ops_create()
>>> drm_gpuva_sm_unmap_ops_create()
>>> + * provides drivers a the list of operations to be executed in order
>>> to unmap
>>> + * a range of GPU VA space. The logic behind this functions 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.
>>> + *
>>> + * The following paragraph depicts the basic constellations of
>>> existent GPU VA
>>> + * mappings, a newly requested mapping and the resulting mappings as
>>> implemented
>>> + * by drm_gpuva_sm_map_ops_create() - it doesn't cover arbitrary
>>> combinations
>>> + * of those constellations.
>>> + *
>>> + * ::
>>> + *
>>> + * 1) Existent mapping is kept.
>>> + * ----------------------------
>>> + *
>>> + * 0 a 1
>>> + * old: |-----------| (bo_offset=n)
>>> + *
>>> + * 0 a 1
>>> + * req: |-----------| (bo_offset=n)
>>> + *
>>> + * 0 a 1
>>> + * new: |-----------| (bo_offset=n)
>>> + *
>>> + *
>>> + * 2) Existent mapping is replaced.
>>> + * --------------------------------
>>> + *
>>> + * 0 a 1
>>> + * old: |-----------| (bo_offset=n)
>>> + *
>>> + * 0 a 1
>>> + * req: |-----------| (bo_offset=m)
>>> + *
>>> + * 0 a 1
>>> + * new: |-----------| (bo_offset=m)
>>> + *
>>> + *
>>> + * 3) Existent mapping is replaced.
>>> + * --------------------------------
>>> + *
>>> + * 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 replaced.
>>> + * --------------------------------
>>> + *
>>> + * 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 bo_offset.
>>> + *
>>> + *
>>> + * 5) Existent mapping is split.
>>> + * -----------------------------
>>> + *
>>> + * 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 kept.
>>> + * ----------------------------
>>> + *
>>> + * 0 a 2
>>> + * old: |-----------| (bo_offset=n)
>>> + *
>>> + * 0 a 1
>>> + * req: |-----| (bo_offset=n)
>>> + *
>>> + * 0 a 2
>>> + * new: |-----------| (bo_offset=n)
>>> + *
>>> + *
>>> + * 7) Existent mapping is split.
>>> + * -----------------------------
>>> + *
>>> + * 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 kept.
>>> + * ----------------------------
>>> + *
>>> + * 0 a 2
>>> + * old: |-----------| (bo_offset=n)
>>> + *
>>> + * 1 a 2
>>> + * req: |-----| (bo_offset=n+1)
>>> + *
>>> + * 0 a 2
>>> + * new: |-----------| (bo_offset=n)
>>> + *
>>> + *
>>> + * 9) Existent mapping is split.
>>> + * -----------------------------
>>> + *
>>> + * 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 merged.
>>> + * -------------------------------
>>> + *
>>> + * 0 a 2
>>> + * old: |-----------| (bo_offset=n)
>>> + *
>>> + * 1 a 3
>>> + * req: |-----------| (bo_offset=n+1)
>>> + *
>>> + * 0 a 3
>>> + * new: |-----------------| (bo_offset=n)
>>> + *
>>> + *
>>> + * 11) Existent mapping is split.
>>> + * ------------------------------
>>> + *
>>> + * 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) Existent mapping is kept.
>>> + * -----------------------------
>>> + *
>>> + * 0 a 3
>>> + * old: |-----------------| (bo_offset=n)
>>> + *
>>> + * 1 a 2
>>> + * req: |-----| (bo_offset=n+1)
>>> + *
>>> + * 0 a 3
>>> + * old: |-----------------| (bo_offset=n)
>>> + *
>>> + *
>>> + * 13) Existent mapping is replaced.
>>> + * ---------------------------------
>>> + *
>>> + * 1 a 2
>>> + * 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.
>>> + *
>>> + *
>>> + * 14) Existent mapping is replaced.
>>> + * ---------------------------------
>>> + *
>>> + * 1 a 2
>>> + * old: |-----| (bo_offset=n)
>>> + *
>>> + * 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 mapping is split.
>>> + * ------------------------------
>>> + *
>>> + * 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)
>>> + *
>>> + *
>>> + * 16) Existent mappings are merged.
>>> + * ---------------------------------
>>> + *
>>> + * 0 a 1
>>> + * old: |-----------| (bo_offset=n)
>>> + *
>>> + * 2 a 3
>>> + * old': |-----------| (bo_offset=n+2)
>>> + *
>>> + * 1 a 2
>>> + * req: |-----------| (bo_offset=n+1)
>>> + *
>>> + * a
>>> + * new: |----------------------------------| (bo_offset=n)
>>> + */
>>> +
>>> +/**
>>> + * 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, destroying and
>>> iterating
>>> + * &drm_gpuva and &drm_gpuva_region objects as well as generating
>>> split and merge
>>> + * operations.
>>> + *
>>> + * The GPU VA manager does take care of the locking of the backing
>>> + * &drm_gem_object buffers GPU VA lists though, unless the provided
>>> functions
>>> + * documentation claims otherwise.
>>> + */
>>> +
>>> +/**
>>> + * 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
>>> + *
>>> + * 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)
>>> +{
>>> + drm_mm_init(&mgr->va_mm, start_offset, range);
>>> + drm_mm_init(&mgr->region_mm, start_offset, range);
>>> +
>>> + mgr->mm_start = start_offset;
>>> + mgr->mm_range = range;
>>> +
>>> + mgr->name = name ? name : "unknown";
>>> +
>>> + memset(&mgr->kernel_alloc_node, 0, sizeof(struct drm_mm_node));
>>> + mgr->kernel_alloc_node.start = reserve_offset;
>>> + mgr->kernel_alloc_node.size = reserve_range;
>>> + drm_mm_reserve_node(&mgr->region_mm, &mgr->kernel_alloc_node);
>>> +}
>>> +EXPORT_SYMBOL(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;
>>> + drm_mm_remove_node(&mgr->kernel_alloc_node);
>>> + drm_mm_takedown(&mgr->va_mm);
>>> + drm_mm_takedown(&mgr->region_mm);
>>> +}
>>> +EXPORT_SYMBOL(drm_gpuva_manager_destroy);
>>> +
>>> +static struct drm_gpuva_region *
>>> +drm_gpuva_in_region(struct drm_gpuva_manager *mgr, u64 addr, u64 range)
>>> +{
>>> + struct drm_gpuva_region *reg;
>>> +
>>> + /* Find the VA region the requested range is strictly enclosed
>>> by. */
>>> + drm_gpuva_for_each_region_in_range(reg, mgr, addr, addr + range) {
>>> + if (reg->node.start <= addr &&
>>> + reg->node.start + reg->node.size >= addr + range &&
>>> + ®->node != &mgr->kernel_alloc_node)
>>> + return reg;
>>> + }
>>> +
>>> + return NULL;
>>> +}
>>> +
>>> +static bool
>>> +drm_gpuva_in_any_region(struct drm_gpuva_manager *mgr, u64 addr, u64
>>> range)
>>> +{
>>> + return !!drm_gpuva_in_region(mgr, addr, range);
>>> +}
>>> +
>>> +/**
>>> + * drm_gpuva_insert - insert a &drm_gpuva
>>> + * @mgr: the &drm_gpuva_manager to insert the &drm_gpuva in
>>> + * @va: the &drm_gpuva to insert
>>> + * @addr: the start address of the GPU VA
>>> + * @range: the range of the GPU VA
>>> + *
>>> + * Insert a &drm_gpuva with a given address and range into a
>>> + * &drm_gpuva_manager.
>>> + *
>>> + * The function assumes the caller does not hold the &drm_gem_object's
>>> + * GPU VA list mutex.
>>> + *
>>> + * Returns: 0 on success, negative error code on failure.
>>> + */
>>> +int
>>> +drm_gpuva_insert(struct drm_gpuva_manager *mgr,
>>> + struct drm_gpuva *va,
>>> + u64 addr, u64 range)
>>> +{
>>> + struct drm_gpuva_region *reg;
>>> + int ret;
>>> +
>>> + if (!va->gem.obj)
>>> + return -EINVAL;
>>> +
>>> + reg = drm_gpuva_in_region(mgr, addr, range);
>>> + if (!reg)
>>> + return -EINVAL;
>>> +
>>> + ret = drm_mm_insert_node_in_range(&mgr->va_mm, &va->node,
>>> + range, 0,
>>> + 0, addr,
>>> + addr + range,
>>> + DRM_MM_INSERT_LOW|DRM_MM_INSERT_ONCE);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + va->mgr = mgr;
>>> + va->region = reg;
>>> +
>>> + return 0;
>>> +}
>>> +EXPORT_SYMBOL(drm_gpuva_insert);
>>> +
>>> +/**
>>> + * drm_gpuva_link_locked - 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.
>>> + *
>>> + * The function assumes the caller already holds the &drm_gem_object's
>>> + * GPU VA list mutex.
>>> + */
>>> +void
>>> +drm_gpuva_link_locked(struct drm_gpuva *va)
>>> +{
>>> + lockdep_assert_held(&va->gem.obj->gpuva.mutex);
>>> + list_add_tail(&va->head, &va->gem.obj->gpuva.list);
>>> +}
>>> +EXPORT_SYMBOL(drm_gpuva_link_locked);
>>> +
>>> +/**
>>> + * drm_gpuva_link_unlocked - unlink a &drm_gpuva
>>> + * @va: the &drm_gpuva to unlink
>>> + *
>>> + * This adds the given &va to the GPU VA list of the &drm_gem_object
>>> it is
>>> + * associated with.
>>> + *
>>> + * The function assumes the caller does not hold the &drm_gem_object's
>>> + * GPU VA list mutex.
>>> + */
>>> +void
>>> +drm_gpuva_link_unlocked(struct drm_gpuva *va)
>>> +{
>>> + drm_gem_gpuva_lock(va->gem.obj);
>>> + drm_gpuva_link_locked(va);
>>> + drm_gem_gpuva_unlock(va->gem.obj);
>>> +}
>>> +EXPORT_SYMBOL(drm_gpuva_link_unlocked);
>>> +
>>> +/**
>>> + * drm_gpuva_unlink_locked - 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.
>>> + *
>>> + * The function assumes the caller already holds the &drm_gem_object's
>>> + * GPU VA list mutex.
>>> + */
>>> +void
>>> +drm_gpuva_unlink_locked(struct drm_gpuva *va)
>>> +{
>>> + lockdep_assert_held(&va->gem.obj->gpuva.mutex);
>>> + list_del_init(&va->head);
>>> +}
>>> +EXPORT_SYMBOL(drm_gpuva_unlink_locked);
>>> +
>>> +/**
>>> + * drm_gpuva_unlink_unlocked - 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.
>>> + *
>>> + * The function assumes the caller does not hold the &drm_gem_object's
>>> + * GPU VA list mutex.
>>> + */
>>> +void
>>> +drm_gpuva_unlink_unlocked(struct drm_gpuva *va)
>>> +{
>>> + drm_gem_gpuva_lock(va->gem.obj);
>>> + drm_gpuva_unlink_locked(va);
>>> + drm_gem_gpuva_unlock(va->gem.obj);
>>> +}
>>> +EXPORT_SYMBOL(drm_gpuva_unlink_unlocked);
>>> +
>>> +/**
>>> + * drm_gpuva_destroy_locked - destroy a &drm_gpuva
>>> + * @va: the &drm_gpuva to destroy
>>> + *
>>> + * This removes the given &va from GPU VA list of the
>>> &drm_gem_object it is
>>> + * associated with and removes it from the underlaying range allocator.
>>> + *
>>> + * The function assumes the caller already holds the &drm_gem_object's
>>> + * GPU VA list mutex.
>>> + */
>>> +void
>>> +drm_gpuva_destroy_locked(struct drm_gpuva *va)
>>> +{
>>> + lockdep_assert_held(&va->gem.obj->gpuva.mutex);
>>> +
>>> + list_del(&va->head);
>>> + drm_mm_remove_node(&va->node);
>>> +}
>>> +EXPORT_SYMBOL(drm_gpuva_destroy_locked);
>>> +
>>> +/**
>>> + * drm_gpuva_destroy_unlocked - destroy a &drm_gpuva
>>> + * @va: the &drm_gpuva to destroy
>>> + *
>>> + * This removes the given &va from GPU VA list of the
>>> &drm_gem_object it is
>>> + * associated with and removes it from the underlaying range allocator.
>>> + *
>>> + * The function assumes the caller does not hold the &drm_gem_object's
>>> + * GPU VA list mutex.
>>> + */
>>> +void
>>> +drm_gpuva_destroy_unlocked(struct drm_gpuva *va)
>>> +{
>>> + drm_gem_gpuva_lock(va->gem.obj);
>>> + list_del(&va->head);
>>> + drm_gem_gpuva_unlock(va->gem.obj);
>>> +
>>> + drm_mm_remove_node(&va->node);
>>> +}
>>> +EXPORT_SYMBOL(drm_gpuva_destroy_unlocked);
>>> +
>>> +/**
>>> + * 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;
>>> +
>>> + drm_gpuva_for_each_va_in_range(va, mgr, addr, range) {
>>> + if (va->node.start == addr &&
>>> + va->node.size == range)
>>> + return va;
>>> + }
>>> +
>>> + return NULL;
>>> +}
>>> +EXPORT_SYMBOL(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)
>>> +{
>>> + struct drm_mm_node *node;
>>> +
>>> + if (start <= mgr->mm_start ||
>>> + start > (mgr->mm_start + mgr->mm_range))
>>> + return NULL;
>>> +
>>> + node = __drm_mm_interval_first(&mgr->va_mm, start - 1, start);
>>> + if (node == &mgr->va_mm.head_node)
>>> + return NULL;
>>> +
>>> + return (struct drm_gpuva *)node;
>>> +}
>>> +EXPORT_SYMBOL(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)
>>> +{
>>> + struct drm_mm_node *node;
>>> +
>>> + if (end < mgr->mm_start ||
>>> + end >= (mgr->mm_start + mgr->mm_range))
>>> + return NULL;
>>> +
>>> + node = __drm_mm_interval_first(&mgr->va_mm, end, end + 1);
>>> + if (node == &mgr->va_mm.head_node)
>>> + return NULL;
>>> +
>>> + return (struct drm_gpuva *)node;
>>> +}
>>> +EXPORT_SYMBOL(drm_gpuva_find_next);
>>> +
>>> +/**
>>> + * drm_gpuva_region_insert - insert a &drm_gpuva_region
>>> + * @mgr: the &drm_gpuva_manager to insert the &drm_gpuva in
>>> + * @reg: the &drm_gpuva_region to insert
>>> + * @addr: the start address of the GPU VA
>>> + * @range: the range of the GPU VA
>>> + *
>>> + * Insert a &drm_gpuva_region with a given address and range into a
>>> + * &drm_gpuva_manager.
>>> + *
>>> + * Returns: 0 on success, negative error code on failure.
>>> + */
>>> +int
>>> +drm_gpuva_region_insert(struct drm_gpuva_manager *mgr,
>>> + struct drm_gpuva_region *reg,
>>> + u64 addr, u64 range)
>>> +{
>>> + int ret;
>>> +
>>> + ret = drm_mm_insert_node_in_range(&mgr->region_mm, ®->node,
>>> + range, 0,
>>> + 0, addr,
>>> + addr + range,
>>> + DRM_MM_INSERT_LOW|
>>> + DRM_MM_INSERT_ONCE);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + reg->mgr = mgr;
>>> +
>>> + return 0;
>>> +}
>>> +EXPORT_SYMBOL(drm_gpuva_region_insert);
>>> +
>>> +/**
>>> + * drm_gpuva_region_destroy - destroy a &drm_gpuva_region
>>> + * @mgr: the &drm_gpuva_manager holding the region
>>> + * @reg: the &drm_gpuva to destroy
>>> + *
>>> + * This removes the given ® from the underlaying range allocator.
>>> + */
>>> +void
>>> +drm_gpuva_region_destroy(struct drm_gpuva_manager *mgr,
>>> + struct drm_gpuva_region *reg)
>>> +{
>>> + struct drm_gpuva *va;
>>> +
>>> + drm_gpuva_for_each_va_in_range(va, mgr,
>>> + reg->node.start,
>>> + reg->node.size) {
>>> + WARN(1, "GPU VA region must be empty on destroy.\n");
>>> + return;
>>> + }
>>> +
>>> + if (®->node == &mgr->kernel_alloc_node) {
>>> + WARN(1, "Can't destroy kernel reserved region.\n");
>>> + return;
>>> + }
>>> +
>>> + drm_mm_remove_node(®->node);
>>> +}
>>> +EXPORT_SYMBOL(drm_gpuva_region_destroy);
>>> +
>>> +/**
>>> + * drm_gpuva_region_find - find a &drm_gpuva_region
>>> + * @mgr: the &drm_gpuva_manager to search in
>>> + * @addr: the &drm_gpuva_regions address
>>> + * @range: the &drm_gpuva_regions range
>>> + *
>>> + * Returns: the &drm_gpuva_region at a given &addr and with a given
>>> &range
>>> + */
>>> +struct drm_gpuva_region *
>>> +drm_gpuva_region_find(struct drm_gpuva_manager *mgr,
>>> + u64 addr, u64 range)
>>> +{
>>> + struct drm_gpuva_region *reg;
>>> +
>>> + drm_gpuva_for_each_region_in_range(reg, mgr, addr, addr + range)
>>> + if (reg->node.start == addr &&
>>> + reg->node.size == range)
>>> + return reg;
>>> +
>>> + return NULL;
>>> +}
>>> +EXPORT_SYMBOL(drm_gpuva_region_find);
>>> +
>>> +static int
>>> +gpuva_op_map_new(struct drm_gpuva_op **pop,
>>> + u64 addr, u64 range,
>>> + struct drm_gem_object *obj, u64 offset)
>>> +{
>>> + struct drm_gpuva_op *op;
>>> +
>>> + op = *pop = kzalloc(sizeof(*op), GFP_KERNEL);
>>> + if (!op)
>>> + return -ENOMEM;
>>> +
>>> + 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 0;
>>> +}
>>> +
>>> +static int
>>> +gpuva_op_remap_new(struct drm_gpuva_op **pop,
>>> + 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 = *pop = kzalloc(sizeof(*op), GFP_KERNEL);
>>> + if (!op)
>>> + return -ENOMEM;
>>> +
>>> + op->op = DRM_GPUVA_OP_REMAP;
>>> + r = &op->remap;
>>> +
>>> + if (prev) {
>>> + r->prev = kmemdup(prev, sizeof(*prev), GFP_KERNEL);
>>> + if (!r->prev)
>>> + goto err_free_op;
>>> + }
>>> +
>>> + if (next) {
>>> + r->next = kmemdup(next, sizeof(*next), GFP_KERNEL);
>>> + if (!r->next)
>>> + goto err_free_prev;
>>> + }
>>> +
>>> + r->unmap = kmemdup(unmap, sizeof(*unmap), GFP_KERNEL);
>>> + if (!r->unmap)
>>> + goto err_free_next;
>>> +
>>> + return 0;
>>> +
>>> +err_free_next:
>>> + if (next)
>>> + kfree(r->next);
>>> +err_free_prev:
>>> + if (prev)
>>> + kfree(r->prev);
>>> +err_free_op:
>>> + kfree(op);
>>> + *pop = NULL;
>>> +
>>> + return -ENOMEM;
>>> +}
>>> +
>>> +static int
>>> +gpuva_op_unmap_new(struct drm_gpuva_op **pop,
>>> + struct drm_gpuva *va, bool merge)
>>> +{
>>> + struct drm_gpuva_op *op;
>>> +
>>> + op = *pop = kzalloc(sizeof(*op), GFP_KERNEL);
>>> + if (!op)
>>> + return -ENOMEM;
>>> +
>>> + op->op = DRM_GPUVA_OP_UNMAP;
>>> + op->unmap.va = va;
>>> + op->unmap.keep = merge;
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +#define op_map_new_to_list(_ops, _addr, _range, \
>>> + _obj, _offset) \
>>> +do { \
>>> + struct drm_gpuva_op *op; \
>>> + \
>>> + ret = gpuva_op_map_new(&op, _addr, _range, \
>>> + _obj, _offset); \
>>> + if (ret) \
>>> + goto err_free_ops; \
>>> + \
>>> + list_add_tail(&op->entry, _ops); \
>>> +} while (0)
>>> +
>>> +#define op_remap_new_to_list(_ops, _prev, _next, \
>>> + _unmap) \
>>> +do { \
>>> + struct drm_gpuva_op *op; \
>>> + \
>>> + ret = gpuva_op_remap_new(&op, _prev, _next, \
>>> + _unmap); \
>>> + if (ret) \
>>> + goto err_free_ops; \
>>> + \
>>> + list_add_tail(&op->entry, _ops); \
>>> +} while (0)
>>> +
>>> +#define op_unmap_new_to_list(_ops, _gpuva, _merge) \
>>> +do { \
>>> + struct drm_gpuva_op *op; \
>>> + \
>>> + ret = gpuva_op_unmap_new(&op, _gpuva, _merge); \
>>> + if (ret) \
>>> + goto err_free_ops; \
>>> + \
>>> + list_add_tail(&op->entry, _ops); \
>>> +} while (0)
>>> +
>>> +/**
>>> + * 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, if existent,
>>> + * represents the original map operation requested by the caller.
>>> Please note
>>> + * that the map operation might has been modified, e.g. if it was
>>> + * merged with an existent mapping.
>>> + *
>>> + * 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 drm_gpuva *va, *prev = NULL;
>>> + u64 req_end = req_addr + req_range;
>>> + bool skip_pmerge = false, skip_nmerge = false;
>>> + int ret;
>>> +
>>> + if (!drm_gpuva_in_any_region(mgr, req_addr, req_range))
>>> + return ERR_PTR(-EINVAL);
>>> +
>>> + ops = kzalloc(sizeof(*ops), GFP_KERNEL);
>>> + if (!ops)
>>> + return ERR_PTR(-ENOMEM);
>>> +
>>> + INIT_LIST_HEAD(&ops->list);
>>> +
>>> + drm_gpuva_for_each_va_in_range(va, mgr, req_addr, req_end) {
>>> + struct drm_gem_object *obj = va->gem.obj;
>>> + u64 offset = va->gem.offset;
>>> + u64 addr = va->node.start;
>>> + u64 range = va->node.size;
>>> + u64 end = addr + range;
>>> +
>>> + /* Generally, we want to skip merging with potential mappings
>>> + * left and right of the requested one when we found a
>>> + * collision, since merging happens in this loop already.
>>> + *
>>> + * However, there is one exception when the requested mapping
>>> + * spans into a free VM area. If this is the case we might
>>> + * still hit the boundary of another mapping before and/or
>>> + * after the free VM area.
>>> + */
>>> + skip_pmerge = true;
>>> + skip_nmerge = true;
>>> +
>>> + if (addr == req_addr) {
>>> + bool merge = obj == req_obj &&
>>> + offset == req_offset;
>>> + if (end == req_end) {
>>> + if (merge)
>>> + goto done;
>>> +
>>> + op_unmap_new_to_list(&ops->list, va, false);
>>> + break;
>>> + }
>>> +
>>> + if (end < req_end) {
>>> + skip_nmerge = false;
>>> + op_unmap_new_to_list(&ops->list, va, merge);
>>> + goto next;
>>> + }
>>> +
>>> + 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 };
>>> +
>>> + if (merge)
>>> + goto done;
>>> +
>>> + op_remap_new_to_list(&ops->list, NULL, &n, &u);
>>> + 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 };
>>> + bool merge = obj == req_obj &&
>>> + offset + ls_range == req_offset;
>>> +
>>> + if (end == req_end) {
>>> + if (merge)
>>> + goto done;
>>> +
>>> + op_remap_new_to_list(&ops->list, &p, NULL, &u);
>>> + break;
>>> + }
>>> +
>>> + if (end < req_end) {
>>> + u64 new_addr = addr;
>>> + u64 new_range = req_range + ls_range;
>>> + u64 new_offset = offset;
>>> +
>>> + /* We validated that the requested mapping is
>>> + * within a single VA region already.
>>> + * Since it overlaps the current mapping (which
>>> + * can't cross a VA region boundary) we can be
>>> + * sure that we're still within the boundaries
>>> + * of the same VA region after merging.
>>> + */
>>> + if (merge) {
>>> + req_offset = new_offset;
>>> + req_addr = new_addr;
>>> + req_range = new_range;
>>> + op_unmap_new_to_list(&ops->list, va, true);
>>> + goto next;
>>> + }
>>> +
>>> + op_remap_new_to_list(&ops->list, &p, NULL, &u);
>>> + goto next;
>>> + }
>>> +
>>> + 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,
>>> + };
>>> +
>>> + if (merge)
>>> + goto done;
>>> +
>>> + op_remap_new_to_list(&ops->list, &p, &n, &u);
>>> + break;
>>> + }
>>> + } else if (addr > req_addr) {
>>> + bool merge = obj == req_obj &&
>>> + offset == req_offset +
>>> + (addr - req_addr);
>>> + if (!prev)
>>> + skip_pmerge = false;
>>> +
>>> + if (end == req_end) {
>>> + op_unmap_new_to_list(&ops->list, va, merge);
>>> + break;
>>> + }
>>> +
>>> + if (end < req_end) {
>>> + skip_nmerge = false;
>>> + op_unmap_new_to_list(&ops->list, va, merge);
>>> + goto next;
>>> + }
>>> +
>>> + 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 };
>>> + u64 new_end = end;
>>> + u64 new_range = new_end - req_addr;
>>> +
>>> + /* We validated that the requested mapping is
>>> + * within a single VA region already.
>>> + * Since it overlaps the current mapping (which
>>> + * can't cross a VA region boundary) we can be
>>> + * sure that we're still within the boundaries
>>> + * of the same VA region after merging.
>>> + */
>>> + if (merge) {
>>> + req_end = new_end;
>>> + req_range = new_range;
>>> + op_unmap_new_to_list(&ops->list, va, true);
>>> + break;
>>> + }
>>> +
>>> + op_remap_new_to_list(&ops->list, NULL, &n, &u);
>>> + break;
>>> + }
>>> + }
>>> +next:
>>> + prev = va;
>>> + }
>>> +
>>> + va = skip_pmerge ? NULL : drm_gpuva_find_prev(mgr, req_addr);
>>> + if (va) {
>>> + struct drm_gem_object *obj = va->gem.obj;
>>> + u64 offset = va->gem.offset;
>>> + u64 addr = va->node.start;
>>> + u64 range = va->node.size;
>>> + u64 new_offset = offset;
>>> + u64 new_addr = addr;
>>> + u64 new_range = req_range + range;
>>> + bool merge = obj == req_obj &&
>>> + offset + range == req_offset;
>>> +
>>> + /* Don't merge over VA region boundaries. */
>>> + merge &= drm_gpuva_in_any_region(mgr, new_addr, new_range);
>>> + if (merge) {
>>> + op_unmap_new_to_list(&ops->list, va, true);
>>> +
>>> + req_offset = new_offset;
>>> + req_addr = new_addr;
>>> + req_range = new_range;
>>> + }
>>> + }
>>> +
>>> + va = skip_nmerge ? NULL : drm_gpuva_find_next(mgr, req_end);
>>> + if (va) {
>>> + struct drm_gem_object *obj = va->gem.obj;
>>> + u64 offset = va->gem.offset;
>>> + u64 addr = va->node.start;
>>> + u64 range = va->node.size;
>>> + u64 end = addr + range;
>>> + u64 new_range = req_range + range;
>>> + u64 new_end = end;
>>> + bool merge = obj == req_obj &&
>>> + offset == req_offset + req_range;
>>> +
>>> + /* Don't merge over VA region boundaries. */
>>> + merge &= drm_gpuva_in_any_region(mgr, req_addr, new_range);
>>> + if (merge) {
>>> + op_unmap_new_to_list(&ops->list, va, true);
>>> +
>>> + req_range = new_range;
>>> + req_end = new_end;
>>> + }
>>> + }
>>> +
>>> + op_map_new_to_list(&ops->list,
>>> + req_addr, req_range,
>>> + req_obj, req_offset);
>>> +
>>> +done:
>>> + return ops;
>>> +
>>> +err_free_ops:
>>> + drm_gpuva_ops_free(ops);
>>> + return ERR_PTR(ret);
>>> +}
>>> +EXPORT_SYMBOL(drm_gpuva_sm_map_ops_create);
>>> +
>>> +#undef op_map_new_to_list
>>> +#undef op_remap_new_to_list
>>> +#undef op_unmap_new_to_list
>>> +
>>> +/**
>>> + * 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 drm_gpuva_op *op;
>>> + struct drm_gpuva_op_remap *r;
>>> + struct drm_gpuva *va;
>>> + u64 req_end = req_addr + req_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_in_range(va, mgr, req_addr, req_end) {
>>> + struct drm_gem_object *obj = va->gem.obj;
>>> + u64 offset = va->gem.offset;
>>> + u64 addr = va->node.start;
>>> + u64 range = va->node.size;
>>> + u64 end = addr + range;
>>> +
>>> + op = kzalloc(sizeof(*op), GFP_KERNEL);
>>> + if (!op) {
>>> + ret = -ENOMEM;
>>> + goto err_free_ops;
>>> + }
>>> +
>>> + r = &op->remap;
>>> +
>>> + if (addr < req_addr) {
>>> + r->prev = kzalloc(sizeof(*r->prev), GFP_KERNEL);
>>> + if (!r->prev) {
>>> + ret = -ENOMEM;
>>> + goto err_free_op;
>>> + }
>>> +
>>> + r->prev->va.addr = addr;
>>> + r->prev->va.range = req_addr - addr;
>>> + r->prev->gem.obj = obj;
>>> + r->prev->gem.offset = offset;
>>> + }
>>> +
>>> + if (end > req_end) {
>>> + r->next = kzalloc(sizeof(*r->next), GFP_KERNEL);
>>> + if (!r->next) {
>>> + ret = -ENOMEM;
>>> + goto err_free_prev;
>>> + }
>>> +
>>> + r->next->va.addr = req_end;
>>> + r->next->va.range = end - req_end;
>>> + r->next->gem.obj = obj;
>>> + r->next->gem.offset = offset + (req_end - addr);
>>> + }
>>> +
>>> + if (op->remap.prev || op->remap.next) {
>>> + op->op = DRM_GPUVA_OP_REMAP;
>>> + r->unmap = kzalloc(sizeof(*r->unmap), GFP_KERNEL);
>>> + if (!r->unmap) {
>>> + ret = -ENOMEM;
>>> + goto err_free_next;
>>> + }
>>> +
>>> + r->unmap->va = va;
>>> + } else {
>>> + op->op = DRM_GPUVA_OP_UNMAP;
>>> + op->unmap.va = va;
>>> + }
>>> +
>>> + list_add_tail(&op->entry, &ops->list);
>>> + }
>>> +
>>> + return ops;
>>> +
>>> +err_free_next:
>>> + if (r->next)
>>> + kfree(r->next);
>>> +err_free_prev:
>>> + if (r->prev)
>>> + kfree(r->prev);
>>> +err_free_op:
>>> + kfree(op);
>>> +err_free_ops:
>>> + drm_gpuva_ops_free(ops);
>>> + return ERR_PTR(ret);
>>> +}
>>> +EXPORT_SYMBOL(drm_gpuva_sm_unmap_ops_create);
>>> +
>>> +/**
>>> + * drm_gpuva_ops_free - free the given &drm_gpuva_ops
>>> + * @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_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) {
>>> + if (op->remap.prev)
>>> + kfree(op->remap.prev);
>>> +
>>> + if (op->remap.next)
>>> + kfree(op->remap.next);
>>> +
>>> + kfree(op->remap.unmap);
>>> + }
>>> + kfree(op);
>>> + }
>>> +
>>> + kfree(ops);
>>> +}
>>> +EXPORT_SYMBOL(drm_gpuva_ops_free);
>>> diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h
>>> index d7c521e8860f..6feacd93aca6 100644
>>> --- a/include/drm/drm_drv.h
>>> +++ b/include/drm/drm_drv.h
>>> @@ -104,6 +104,12 @@ enum drm_driver_feature {
>>> * acceleration should be handled by two drivers that are
>>> connected using auxiliary bus.
>>> */
>>> DRIVER_COMPUTE_ACCEL = BIT(7),
>>> + /**
>>> + * @DRIVER_GEM_GPUVA:
>>> + *
>>> + * Driver supports user defined GPU VA bindings for GEM objects.
>>> + */
>>> + DRIVER_GEM_GPUVA = BIT(8),
>>> /* IMPORTANT: Below are all the legacy flags, add new ones
>>> above. */
>>> diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
>>> index 772a4adf5287..4a3679034966 100644
>>> --- a/include/drm/drm_gem.h
>>> +++ b/include/drm/drm_gem.h
>>> @@ -36,6 +36,8 @@
>>> #include <linux/kref.h>
>>> #include <linux/dma-resv.h>
>>> +#include <linux/list.h>
>>> +#include <linux/mutex.h>
>>> #include <drm/drm_vma_manager.h>
>>> @@ -337,6 +339,17 @@ struct drm_gem_object {
>>> */
>>> struct dma_resv _resv;
>>> + /**
>>> + * @gpuva:
>>> + *
>>> + * Provides the list and list mutex of GPU VAs attached to this
>>> + * GEM object.
>>> + */
>>> + struct {
>>> + struct list_head list;
>>> + struct mutex mutex;
>>> + } gpuva;
>>> +
>>> /**
>>> * @funcs:
>>> *
>>> @@ -479,4 +492,66 @@ void drm_gem_lru_move_tail(struct drm_gem_lru
>>> *lru, struct drm_gem_object *obj);
>>> unsigned long drm_gem_lru_scan(struct drm_gem_lru *lru, unsigned
>>> nr_to_scan,
>>> bool (*shrink)(struct drm_gem_object *obj));
>>> +/**
>>> + * drm_gem_gpuva_init - initialize the gpuva list of a GEM object
>>> + * @obj: the &drm_gem_object
>>> + *
>>> + * This initializes the &drm_gem_object's &drm_gpuva list and the mutex
>>> + * protecting it.
>>> + *
>>> + * Calling this function is only necessary for drivers intending to
>>> support the
>>> + * &drm_driver_feature DRIVER_GEM_GPUVA.
>>> + */
>>> +static inline void drm_gem_gpuva_init(struct drm_gem_object *obj)
>>> +{
>>> + INIT_LIST_HEAD(&obj->gpuva.list);
>>> + mutex_init(&obj->gpuva.mutex);
>>> +}
>>> +
>>> +/**
>>> + * drm_gem_gpuva_lock - lock the GEM's gpuva list mutex
>>> + * @obj: the &drm_gem_object
>>> + *
>>> + * This unlocks the mutex protecting the &drm_gem_object's
>>> &drm_gpuva list.
>>> + */
>>> +static inline void drm_gem_gpuva_lock(struct drm_gem_object *obj)
>>> +{
>>> + mutex_lock(&obj->gpuva.mutex);
>>> +}
>>> +
>>> +/**
>>> + * drm_gem_gpuva_unlock - unlock the GEM's gpuva list mutex
>>> + * @obj: the &drm_gem_object
>>> + *
>>> + * This unlocks the mutex protecting the &drm_gem_object's
>>> &drm_gpuva list.
>>> + */
>>> +static inline void drm_gem_gpuva_unlock(struct drm_gem_object *obj)
>>> +{
>>> + mutex_unlock(&obj->gpuva.mutex);
>>> +}
>>> +
>>> +/**
>>> + * drm_gem_for_each_gpuva - iternator to walk over a list of gpuvas
>>> + * @entry: &drm_gpuva structure to assign to in each iteration step
>>> + * @obj: the &drm_gem_object the &drm_gpuvas to walk are associated
>>> with
>>> + *
>>> + * This iterator walks over all &drm_gpuva structures associated
>>> with the
>>> + * &drm_gpuva_manager.
>>> + */
>>> +#define drm_gem_for_each_gpuva(entry, obj) \
>>> + list_for_each_entry(entry, &obj->gpuva.list, head)
>>> +
>>> +/**
>>> + * drm_gem_for_each_gpuva_safe - iternator to safely walk over a
>>> list of gpuvas
>>> + * @entry: &drm_gpuva structure to assign to in each iteration step
>>> + * @next: &next &drm_gpuva to store the next step
>>> + * @obj: the &drm_gem_object the &drm_gpuvas to walk are associated
>>> with
>>> + *
>>> + * This iterator walks over all &drm_gpuva structures associated
>>> with the
>>> + * &drm_gem_object. It is implemented with
>>> list_for_each_entry_safe(), hence
>>> + * it is save against removal of elements.
>>> + */
>>> +#define drm_gem_for_each_gpuva_safe(entry, next, obj) \
>>> + list_for_each_entry_safe(entry, next, &obj->gpuva.list, head)
>>> +
>>> #endif /* __DRM_GEM_H__ */
>>> diff --git a/include/drm/drm_gpuva_mgr.h b/include/drm/drm_gpuva_mgr.h
>>> new file mode 100644
>>> index 000000000000..adeb0c916e91
>>> --- /dev/null
>>> +++ b/include/drm/drm_gpuva_mgr.h
>>> @@ -0,0 +1,527 @@
>>> +// SPDX-License-Identifier: GPL-2.0
>>> +
>>> +#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 <drm/drm_mm.h>
>>> +#include <linux/mm.h>
>>> +#include <linux/rbtree.h>
>>> +#include <linux/spinlock.h>
>>> +#include <linux/types.h>
>>> +
>>> +struct drm_gpuva_region;
>>> +struct drm_gpuva;
>>> +struct drm_gpuva_ops;
>>> +
>>> +/**
>>> + * struct drm_gpuva_manager - DRM GPU VA Manager
>>> + *
>>> + * The DRM GPU VA Manager keeps track of a GPU's virtual address
>>> space by using
>>> + * the &drm_mm range allocator. 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;
>>> +
>>> + /**
>>> + * @region_mm: the &drm_mm range allocator to track GPU VA regions
>>> + */
>>> + struct drm_mm region_mm;
>>> +
>>> + /**
>>> + * @va_mm: the &drm_mm range allocator to track GPU VA mappings
>>> + */
>>> + struct drm_mm va_mm;
>>> +
>>> + /**
>>> + * @kernel_alloc_node:
>>> + *
>>> + * &drm_mm_node representing the address space cutout reserved for
>>> + * the kernel
>>> + */
>>> + struct drm_mm_node kernel_alloc_node;
>>> +};
>>> +
>>> +void drm_gpuva_manager_init(struct drm_gpuva_manager *mgr,
>>> + const char *name,
>>> + u64 start_offset, u64 range,
>>> + u64 reserve_offset, u64 reserve_range);
>>> +void drm_gpuva_manager_destroy(struct drm_gpuva_manager *mgr);
>>> +
>>> +/**
>>> + * struct drm_gpuva_region - structure to track a portion of GPU VA
>>> space
>>> + *
>>> + * This structure represents a portion of a GPUs VA space and is
>>> associated
>>> + * with a &drm_gpuva_manager. Internally it is based on a &drm_mm_node.
>>> + *
>>> + * GPU VA mappings, represented by &drm_gpuva objects, are
>>> restricted to be
>>> + * placed within a &drm_gpuva_region.
>>> + */
>>> +struct drm_gpuva_region {
>>> + /**
>>> + * @node: the &drm_mm_node to track the GPU VA region
>>> + */
>>> + struct drm_mm_node node;
>>> +
>>> + /**
>>> + * @mgr: the &drm_gpuva_manager this object is associated with
>>> + */
>>> + struct drm_gpuva_manager *mgr;
>>> +
>>> + /**
>>> + * @sparse: indicates whether this region is sparse
>>> + */
>>> + bool sparse;
>>> +};
>>> +
>>> +struct drm_gpuva_region *
>>> +drm_gpuva_region_find(struct drm_gpuva_manager *mgr,
>>> + u64 addr, u64 range);
>>> +int drm_gpuva_region_insert(struct drm_gpuva_manager *mgr,
>>> + struct drm_gpuva_region *reg,
>>> + u64 addr, u64 range);
>>> +void drm_gpuva_region_destroy(struct drm_gpuva_manager *mgr,
>>> + struct drm_gpuva_region *reg);
>>> +
>>> +int drm_gpuva_insert(struct drm_gpuva_manager *mgr,
>>> + struct drm_gpuva *va,
>>> + u64 addr, u64 range);
>>> +/**
>>> + * drm_gpuva_for_each_region_in_range - iternator to walk over a
>>> range of nodes
>>> + * @node__: &drm_gpuva_region structure to assign to in each
>>> iteration step
>>> + * @gpuva__: &drm_gpuva_manager structure to walk
>>> + * @start__: starting offset, the first node will overlap this
>>> + * @end__: ending offset, the last node will start before this (but
>>> may overlap)
>>> + *
>>> + * This iterator walks over all nodes in the range allocator that lie
>>> + * between @start and @end. It is implemented similarly to
>>> list_for_each(),
>>> + * but is using &drm_mm's internal interval tree to accelerate the
>>> search for
>>> + * the starting node, 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.
>>> + * If [@start, @end] are beyond the range of the &drm_gpuva_manager,
>>> the
>>> + * iterator may walk over the special _unallocated_
>>> &drm_mm.head_node of the
>>> + * backing &drm_mm, and may even continue indefinitely.
>>> + */
>>> +#define drm_gpuva_for_each_region_in_range(node__, gpuva__, start__,
>>> end__) \
>>> + for (node__ = (struct drm_gpuva_region
>>> *)__drm_mm_interval_first(&(gpuva__)->region_mm, \
>>> + (start__), (end__)-1); \
>>> + node__->node.start < (end__); \
>>> + node__ = (struct drm_gpuva_region
>>> *)list_next_entry(&node__->node, node_list))
>>> +
>>> +/**
>>> + * drm_gpuva_for_each_region - iternator to walk over a range of nodes
>>> + * @entry: &drm_gpuva_region structure to assign to in each
>>> iteration step
>>> + * @gpuva: &drm_gpuva_manager structure to walk
>>> + *
>>> + * This iterator walks over all &drm_gpuva_region structures
>>> associated with the
>>> + * &drm_gpuva_manager.
>>> + */
>>> +#define drm_gpuva_for_each_region(entry, gpuva) \
>>> + list_for_each_entry(entry, drm_mm_nodes(&(gpuva)->region_mm),
>>> node.node_list)
>>> +
>>> +/**
>>> + * drm_gpuva_for_each_region_safe - iternator to safely walk over a
>>> range of
>>> + * nodes
>>> + * @entry: &drm_gpuva_region structure to assign to in each
>>> iteration step
>>> + * @next: &next &drm_gpuva_region to store the next step
>>> + * @gpuva: &drm_gpuva_manager structure to walk
>>> + *
>>> + * This iterator walks over all &drm_gpuva_region structures
>>> associated with the
>>> + * &drm_gpuva_manager. It is implemented with list_for_each_safe(),
>>> so save
>>> + * against removal of elements.
>>> + */
>>> +#define drm_gpuva_for_each_region_safe(entry, next, gpuva) \
>>> + list_for_each_entry_safe(entry, next,
>>> drm_mm_nodes(&(gpuva)->region_mm), node.node_list)
>>> +
>>> +
>>> +/**
>>> + * enum drm_gpuva_flags - flags for struct drm_gpuva
>>> + */
>>> +enum drm_gpuva_flags {
>>> + /**
>>> + * @DRM_GPUVA_SWAPPED: flag indicating that the &drm_gpuva is
>>> swapped
>>> + */
>>> + DRM_GPUVA_SWAPPED = (1 << 0),
>>> +};
>>> +
>>> +/**
>>> + * 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. Internally it is based on a &drm_mm_node.
>>> + *
>>> + * Typically, this structure is embedded in bigger driver structures.
>>> + */
>>> +struct drm_gpuva {
>>> + /**
>>> + * @node: the &drm_mm_node to track the GPU VA mapping
>>> + */
>>> + struct drm_mm_node node;
>>> +
>>> + /**
>>> + * @mgr: the &drm_gpuva_manager this object is associated with
>>> + */
>>> + struct drm_gpuva_manager *mgr;
>>> +
>>> + /**
>>> + * @region: the &drm_gpuva_region the &drm_gpuva is mapped in
>>> + */
>>> + struct drm_gpuva_region *region;
>>> +
>>> + /**
>>> + * @head: the &list_head to attach this object to a &drm_gem_object
>>> + */
>>> + struct list_head head;
>>> +
>>> + /**
>>> + * @flags: the &drm_gpuva_flags for this mapping
>>> + */
>>> + enum drm_gpuva_flags flags;
>>> +
>>> + /**
>>> + * @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;
>>> + } gem;
>>> +};
>>> +
>>> +void drm_gpuva_link_locked(struct drm_gpuva *va);
>>> +void drm_gpuva_link_unlocked(struct drm_gpuva *va);
>>> +void drm_gpuva_unlink_locked(struct drm_gpuva *va);
>>> +void drm_gpuva_unlink_unlocked(struct drm_gpuva *va);
>>> +
>>> +void drm_gpuva_destroy_locked(struct drm_gpuva *va);
>>> +void drm_gpuva_destroy_unlocked(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_prev(struct drm_gpuva_manager *mgr,
>>> u64 start);
>>> +struct drm_gpuva *drm_gpuva_find_next(struct drm_gpuva_manager *mgr,
>>> u64 end);
>>> +
>>> +/**
>>> + * drm_gpuva_swap - sets whether the backing BO of this &drm_gpuva
>>> is swapped
>>> + * @va: the &drm_gpuva to set the swap flag of
>>> + * @swap: indicates whether the &drm_gpuva is swapped
>>> + */
>>> +static inline void drm_gpuva_swap(struct drm_gpuva *va, bool swap)
>>> +{
>>> + if (swap)
>>> + va->flags |= DRM_GPUVA_SWAPPED;
>>> + else
>>> + va->flags &= ~DRM_GPUVA_SWAPPED;
>>> +}
>>> +
>>> +/**
>>> + * drm_gpuva_swapped - indicates whether the backing BO of this
>>> &drm_gpuva
>>> + * is swapped
>>> + * @va: the &drm_gpuva to check
>>> + */
>>> +static inline bool drm_gpuva_swapped(struct drm_gpuva *va)
>>> +{
>>> + return va->flags & DRM_GPUVA_SWAPPED;
>>> +}
>>> +
>>> +/**
>>> + * drm_gpuva_for_each_va_in_range - iternator to walk over a range
>>> of nodes
>>> + * @node__: &drm_gpuva structure to assign to in each iteration step
>>> + * @gpuva__: &drm_gpuva_manager structure to walk
>>> + * @start__: starting offset, the first node will overlap this
>>> + * @end__: ending offset, the last node will start before this (but
>>> may overlap)
>>> + *
>>> + * This iterator walks over all nodes in the range allocator that lie
>>> + * between @start and @end. It is implemented similarly to
>>> list_for_each(),
>>> + * but is using &drm_mm's internal interval tree to accelerate the
>>> search for
>>> + * the starting node, 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.
>>> + * If [@start, @end] are beyond the range of the &drm_gpuva_manager,
>>> the
>>> + * iterator may walk over the special _unallocated_
>>> &drm_mm.head_node of the
>>> + * backing &drm_mm, and may even continue indefinitely.
>>> + */
>>> +#define drm_gpuva_for_each_va_in_range(node__, gpuva__, start__,
>>> end__) \
>>> + for (node__ = (struct drm_gpuva
>>> *)__drm_mm_interval_first(&(gpuva__)->va_mm, \
>>> + (start__), (end__)-1); \
>>> + node__->node.start < (end__); \
>>> + node__ = (struct drm_gpuva *)list_next_entry(&node__->node,
>>> node_list))
>>> +
>>> +/**
>>> + * drm_gpuva_for_each_va - iternator to walk over a range of nodes
>>> + * @entry: &drm_gpuva structure to assign to in each iteration step
>>> + * @gpuva: &drm_gpuva_manager structure to walk
>>> + *
>>> + * This iterator walks over all &drm_gpuva structures associated
>>> with the
>>> + * &drm_gpuva_manager.
>>> + */
>>> +#define drm_gpuva_for_each_va(entry, gpuva) \
>>> + list_for_each_entry(entry, drm_mm_nodes(&(gpuva)->va_mm),
>>> node.node_list)
>>> +
>>> +/**
>>> + * drm_gpuva_for_each_va_safe - iternator to safely walk over a
>>> range of
>>> + * nodes
>>> + * @entry: &drm_gpuva structure to assign to in each iteration step
>>> + * @next: &next &drm_gpuva to store the next step
>>> + * @gpuva: &drm_gpuva_manager structure to walk
>>> + *
>>> + * This iterator walks over all &drm_gpuva structures associated
>>> with the
>>> + * &drm_gpuva_manager. It is implemented with list_for_each_safe(),
>>> so save
>>> + * against removal of elements.
>>> + */
>>> +#define drm_gpuva_for_each_va_safe(entry, next, gpuva) \
>>> + list_for_each_entry_safe(entry, next,
>>> drm_mm_nodes(&(gpuva)->va_mm), node.node_list)
>>> +
>>> +/**
>>> + * enum drm_gpuva_op_type - GPU VA operation type
>>> + *
>>> + * Operations to alter the GPU VA mappings tracked by the
>>> &drm_gpuva_manager
>>> + * can be map, remap or unmap operations.
>>> + */
>>> +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,
>>> +};
>>> +
>>> +/**
>>> + * 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 - GPU VA operation
>>> + *
>>> + * This structure represents a single generic operation, which can
>>> be either
>>> + * map, unmap or remap.
>>> + *
>>> + * 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;
>>> +
>>> + /**
>>> + * @unmap: the unmap operation
>>> + */
>>> + struct drm_gpuva_op_unmap unmap;
>>> +
>>> + /**
>>> + * @remap: the remap operation
>>> + */
>>> + struct drm_gpuva_op_remap remap;
>>> + };
>>> +};
>>> +
>>> +/**
>>> + * 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 all 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 all 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)
>>> +
>>> +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);
>>> +void drm_gpuva_ops_free(struct drm_gpuva_ops *ops);
>>> +
>>> +#endif /* __DRM_GPUVA_MGR_H__ */
>>> --
>>> 2.39.0
>>>
>
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