linux-stable.git/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c, branch linux-5.4.y

drm/amdgpu: use atomic functions with memory barriers for vm fault info

2025-10-29T13:00:01+00:00

[ Upstream commit 6df8e84aa6b5b1812cc2cacd6b3f5ccbb18cda2b ]

The atomic variable vm_fault_info_updated is used to synchronize access to
adev->gmc.vm_fault_info between the interrupt handler and
get_vm_fault_info().

The default atomic functions like atomic_set() and atomic_read() do not
provide memory barriers. This allows for CPU instruction reordering,
meaning the memory accesses to vm_fault_info and the vm_fault_info_updated
flag are not guaranteed to occur in the intended order. This creates a
race condition that can lead to inconsistent or stale data being used.

The previous implementation, which used an explicit mb(), was incomplete
and inefficient. It failed to account for all potential CPU reorderings,
such as the access of vm_fault_info being reordered before the atomic_read
of the flag. This approach is also more verbose and less performant than
using the proper atomic functions with acquire/release semantics.

Fix this by switching to atomic_set_release() and atomic_read_acquire().
These functions provide the necessary acquire and release semantics,
which act as memory barriers to ensure the correct order of operations.
It is also more efficient and idiomatic than using explicit full memory
barriers.

Fixes: b97dfa27ef3a ("drm/amdgpu: save vm fault information for amdkfd")
Cc: stable@vger.kernel.org
Signed-off-by: Gui-Dong Han 
Signed-off-by: Felix Kuehling 
Reviewed-by: Felix Kuehling 
Signed-off-by: Alex Deucher 
[ kept kgd_dev parameter and adev cast in amdgpu_amdkfd_gpuvm_get_vm_fault_info ]
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

drm/amdgpu: Fix leak when GPU memory allocation fails

2024-05-02T14:18:36+00:00

commit 25e9227c6afd200bed6774c866980b8e36d033af upstream.

Free the sync object if the memory allocation fails for any
reason.

Signed-off-by: Mukul Joshi 
Reviewed-by: Alex Deucher 
Signed-off-by: Alex Deucher 
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

drm/amdkfd: Use drm_priv to pass VM from KFD to amdgpu

2022-05-12T10:23:47+00:00

commit b40a6ab2cf9213923bf8e821ce7fa7f6a0a26990 upstream.

amdgpu_amdkfd_gpuvm_alloc_memory_of_gpu needs the drm_priv to allow mmap
to access the BO through the corresponding file descriptor. The VM can
also be extracted from drm_priv, so drm_priv can replace the vm parameter
in the kfd2kgd interface.

Signed-off-by: Felix Kuehling 
Reviewed-by: Philip Yang 
Signed-off-by: Alex Deucher 
[This is a partial cherry-pick of the upstream commit.]
Signed-off-by: Lee Jones 
Signed-off-by: Greg Kroah-Hartman

drm/amdkfd: use allowed domain for vmbo validation

2021-07-19T06:53:10+00:00

[ Upstream commit bc05716d4fdd065013633602c5960a2bf1511b9c ]

Fixes handling when page tables are in system memory.

v3: remove struct amdgpu_vm_parser.
v2: remove unwanted variable.
    change amdgpu_amdkfd_validate instead of amdgpu_amdkfd_bo_validate.

Signed-off-by: Nirmoy Das 
Reviewed-by: Christian König 
Reviewed-by: Felix Kuehling 
Signed-off-by: Alex Deucher 
Signed-off-by: Sasha Levin

drm/amdkfd: fix restore worker race condition

2020-10-01T11:18:03+00:00

[ Upstream commit f7646585a30ed8ef5ab300d4dc3b0c1d6afbe71d ]

In free memory of gpu path, remove bo from validate_list to make sure
restore worker don't access the BO any more, then unregister bo MMU
interval notifier. Otherwise, the restore worker will crash in the
middle of validating BO user pages if MMU interval notifer is gone.

Signed-off-by: Philip Yang 
Reviewed-by: Felix Kuehling 
Signed-off-by: Alex Deucher 
Signed-off-by: Sasha Levin

drm/amdgpu: Use GEM obj reference for KFD BOs

2020-06-03T06:21:11+00:00

[ Upstream commit 39b3128d7ffd44e400e581e6f49e88cb42bef9a1 ]

Releasing the AMDGPU BO ref directly leads to problems when BOs were
exported as DMA bufs. Releasing the GEM reference makes sure that the
AMDGPU/TTM BO is not freed too early.

Also take a GEM reference when importing BOs from DMABufs to keep
references to imported BOs balances properly.

Signed-off-by: Felix Kuehling 
Tested-by: Alex Sierra 
Acked-by: Christian König 
Reviewed-by: Alex Sierra 
Signed-off-by: Alex Deucher 
Signed-off-by: Sasha Levin

drm/amdgpu: untag user pointers

2019-09-26T00:51:41+00:00

This patch is a part of a series that extends kernel ABI to allow to pass
tagged user pointers (with the top byte set to something else other than
0x00) as syscall arguments.

In amdgpu_gem_userptr_ioctl() and amdgpu_amdkfd_gpuvm.c/init_user_pages()
an MMU notifier is set up with a (tagged) userspace pointer.  The untagged
address should be used so that MMU notifiers for the untagged address get
correctly matched up with the right BO.  This patch untag user pointers in
amdgpu_gem_userptr_ioctl() for the GEM case and in amdgpu_amdkfd_gpuvm_
alloc_memory_of_gpu() for the KFD case.  This also makes sure that an
untagged pointer is passed to amdgpu_ttm_tt_get_user_pages(), which uses
it for vma lookups.

Link: http://lkml.kernel.org/r/d684e1df08f2ecb6bc292e222b64fa9efbc26e69.1563904656.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov 
Reviewed-by: Kees Cook 
Suggested-by: Felix Kuehling 
Acked-by: Felix Kuehling 
Cc: Al Viro 
Cc: Catalin Marinas 
Cc: Dave Hansen 
Cc: Eric Auger 
Cc: Jens Wiklander 
Cc: Khalid Aziz 
Cc: Mauro Carvalho Chehab 
Cc: Mike Rapoport 
Cc: Vincenzo Frascino 
Cc: Will Deacon 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge tag 'drm-misc-next-2019-08-19' of git://anongit.freedesktop.org/drm/drm-misc into drm-next

2019-08-21T06:44:41+00:00

drm-misc-next for 5.4:

UAPI Changes:

Cross-subsystem Changes:

Core Changes:
  - dma-buf: add reservation_object_fences helper, relax
             reservation_object_add_shared_fence, remove
             reservation_object seq number (and then
             restored)
  - dma-fence: Shrinkage of the dma_fence structure,
               Merge dma_fence_signal and dma_fence_signal_locked,
               Store the timestamp in struct dma_fence in a union with
               cb_list

Driver Changes:
  - More dt-bindings YAML conversions
  - More removal of drmP.h includes
  - dw-hdmi: Support get_eld and various i2s improvements
  - gm12u320: Few fixes
  - meson: Global cleanup
  - panfrost: Few refactors, Support for GPU heap allocations
  - sun4i: Support for DDC enable GPIO
  - New panels: TI nspire, NEC NL8048HL11, LG Philips LB035Q02,
                Sharp LS037V7DW01, Sony ACX565AKM, Toppoly TD028TTEC1
                Toppoly TD043MTEA1

Signed-off-by: Dave Airlie 
[airlied: fixup dma_resv rename fallout]

From: Maxime Ripard 
Link: https://patchwork.freedesktop.org/patch/msgid/20190819141923.7l2adietcr2pioct@flea

dma-buf: Restore seqlock around dma_resv updates

2019-08-16T11:40:58+00:00

This reverts
67c97fb79a7f ("dma-buf: add reservation_object_fences helper")
dd7a7d1ff2f1 ("drm/i915: use new reservation_object_fences helper")
0e1d8083bddb ("dma-buf: further relax reservation_object_add_shared_fence")
5d344f58da76 ("dma-buf: nuke reservation_object seq number")

The scenario that defeats simply grabbing a set of shared/exclusive
fences and using them blissfully under RCU is that any of those fences
may be reallocated by a SLAB_TYPESAFE_BY_RCU fence slab cache. In this
scenario, while keeping the rcu_read_lock we need to establish that no
fence was changed in the dma_resv after a read (or full) memory barrier.

Signed-off-by: Chris Wilson 
Cc: Chris Wilson 
Cc: Daniel Vetter 
Acked-by: Christian König 
Link: https://patchwork.freedesktop.org/patch/msgid/20190814182401.25009-1-chris@chris-wilson.co.uk

dma-buf: rename reservation_object to dma_resv

2019-08-13T07:09:30+00:00

Be more consistent with the naming of the other DMA-buf objects.

Signed-off-by: Christian König 
Reviewed-by: Chris Wilson 
Link: https://patchwork.freedesktop.org/patch/323401/