linux.git/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h, branch v7.2-rc2 Linux kernel source tree drm/amdgpu: Fix AMDGPU_GTT_MAX_TRANSFER_SIZE for non-4K systems 2026-07-01T17:02:00+00:00 Donet Tom donettom@linux.ibm.com 2026-06-25T07:52:06+00:00 8b7033c0c5dcc3b3bd8403453d2793ec4514ae62 Running RCCL unit tests on a system with a 64K PAGE_SIZE triggers the following warning and causes the test to terminate on latest upstream kernel: WARNING: drivers/gpu/drm/amd/amdgpu/amdgpu_object.c:1335 at amdgpu_bo_release_notify+0x1bc/0x280 [amdgpu], CPU#18: rccl-UnitTests/33151 Call trace: amdgpu_bo_release_notify ttm_bo_release amdgpu_gem_object_free drm_gem_object_free amdgpu_bo_unref amdgpu_bo_create amdgpu_bo_create_user amdgpu_gem_object_create amdgpu_amdkfd_gpuvm_alloc_memory_of_gpu kfd_ioctl_alloc_memory_of_gpu kfd_ioctl sys_ioctl The warning is triggered because amdgpu_ttm_next_clear_entity() returns NULL when a clear buffer operation is requested. This happens because the GART window allocation for the default_entity, clear_entity and move_entity fails during initialization. Commit [1] introduced separate GART windows for the default_entity, clear_entity and move_entity of each SDMA instance. Their sizes are derived from AMDGPU_GTT_MAX_TRANSFER_SIZE, which is currently defined as 1024 pages. This implicitly assumes a 4K PAGE_SIZE, where 1024 pages correspond to a 4MB transfer. On a 64K PAGE_SIZE system, however, the same value expands to 64MB. The default_entity and clear_entity each allocate one AMDGPU_GTT_MAX_TRANSFER_SIZE GART window, while the move_entity allocates two such windows. This results in 16MB of GART space per SDMA instance on a 4K PAGE_SIZE system, but 256MB per SDMA instance on a 64K PAGE_SIZE system. On an MI210 system with five SDMA instances and a 512MB GART aperture, the total GART space required becomes 1.25GB, exceeding the available GART aperture. Consequently, GART window allocation fails, amdgpu_ttm_next_clear_entity() returns NULL, and the above warning is triggered. Redefine AMDGPU_GTT_MAX_TRANSFER_SIZE in bytes instead of page units. Where a page count is required, convert it using PAGE_SHIFT. This preserves the existing 4MB transfer size across all PAGE_SIZE configurations while keeping GART window allocations within the available GART aperture. [1] https://lore.kernel.org/all/20260408100327.1372-3-pierre-eric.pelloux-prayer@amd.com/#t Closes: https://gitlab.freedesktop.org/drm/amd/-/work_items/5435 Fixes: 897ee11ec020 ("drm/amdgpu: create multiple clear/move ttm entities") Signed-off-by: Donet Tom <donettom@linux.ibm.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> (cherry picked from commit 27213b776a666d3030de5acc3cd75278197b0494) Cc: stable@vger.kernel.org 
Running RCCL unit tests on a system with a 64K PAGE_SIZE triggers
the following warning and causes the test to terminate on latest
upstream kernel:

WARNING: drivers/gpu/drm/amd/amdgpu/amdgpu_object.c:1335 at
amdgpu_bo_release_notify+0x1bc/0x280 [amdgpu],
CPU#18: rccl-UnitTests/33151

Call trace:
amdgpu_bo_release_notify
ttm_bo_release
amdgpu_gem_object_free
drm_gem_object_free
amdgpu_bo_unref
amdgpu_bo_create
amdgpu_bo_create_user
amdgpu_gem_object_create
amdgpu_amdkfd_gpuvm_alloc_memory_of_gpu
kfd_ioctl_alloc_memory_of_gpu
kfd_ioctl
sys_ioctl

The warning is triggered because
amdgpu_ttm_next_clear_entity() returns NULL when a clear buffer
operation is requested. This happens because the GART window
allocation for the default_entity, clear_entity and move_entity
fails during initialization.

Commit [1] introduced separate GART windows for the
default_entity, clear_entity and move_entity of each SDMA
instance. Their sizes are derived from
AMDGPU_GTT_MAX_TRANSFER_SIZE, which is currently defined as 1024
pages. This implicitly assumes a 4K PAGE_SIZE, where 1024 pages
correspond to a 4MB transfer. On a 64K PAGE_SIZE system, however,
the same value expands to 64MB.

The default_entity and clear_entity each allocate one
AMDGPU_GTT_MAX_TRANSFER_SIZE GART window, while the move_entity
allocates two such windows. This results in 16MB of GART space
per SDMA instance on a 4K PAGE_SIZE system, but 256MB per SDMA
instance on a 64K PAGE_SIZE system.

On an MI210 system with five SDMA instances and a 512MB GART
aperture, the total GART space required becomes 1.25GB,
exceeding the available GART aperture. Consequently, GART window
allocation fails, amdgpu_ttm_next_clear_entity() returns NULL,
and the above warning is triggered.

Redefine AMDGPU_GTT_MAX_TRANSFER_SIZE in bytes instead of page
units. Where a page count is required, convert it using
PAGE_SHIFT. This preserves the existing 4MB transfer size across
all PAGE_SIZE configurations while keeping GART window
allocations within the available GART aperture.

[1] https://lore.kernel.org/all/20260408100327.1372-3-pierre-eric.pelloux-prayer@amd.com/#t

Closes: https://gitlab.freedesktop.org/drm/amd/-/work_items/5435
Fixes: 897ee11ec020 ("drm/amdgpu: create multiple clear/move ttm entities")
Signed-off-by: Donet Tom <donettom@linux.ibm.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 27213b776a666d3030de5acc3cd75278197b0494)
Cc: stable@vger.kernel.org
drm/amdgpu: split amdgpu_ttm_set_buffer_funcs_status in 2 funcs 2026-04-17T19:41:13+00:00 Pierre-Eric Pelloux-Prayer pierre-eric.pelloux-prayer@amd.com 2026-01-08T16:55:45+00:00 a80df5715778d2b3496c6f971347d781bd7cd56f Makes a code slightly clearer and reduces indentation. --- v5: use amdgpu_in_reset in amdgpu_ttm_disable_buffer_funcs --- Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com> Suggested-by: Christian König <christian.koenig@amd.com> Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> 
Makes a code slightly clearer and reduces indentation.

---
v5: use amdgpu_in_reset in amdgpu_ttm_disable_buffer_funcs
---

Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
Suggested-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
drm/amdgpu: rename amdgpu_fill_buffer as amdgpu_ttm_clear_buffer 2026-04-17T19:41:13+00:00 Pierre-Eric Pelloux-Prayer pierre-eric.pelloux-prayer@amd.com 2025-09-05T08:22:22+00:00 5bd8aab55bc18a744577bff79a8c58b031e3c05d This is the only use case for this function. --- v2: amdgpu_ttm_clear_buffer instead of amdgpu_clear_buffer --- Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com> Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> 
This is the only use case for this function.

---
v2: amdgpu_ttm_clear_buffer instead of amdgpu_clear_buffer
---

Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
drm/amdgpu: get rid of amdgpu_ttm_clear_buffer 2026-04-17T19:41:13+00:00 Pierre-Eric Pelloux-Prayer pierre-eric.pelloux-prayer@amd.com 2025-11-18T14:48:39+00:00 23bd7e67961ee531386246e98021273bb45b0a84 It's doing the same thing as amdgpu_fill_buffer(src_data=0), so drop it. The only caveat is that amdgpu_res_cleared() return value is only valid right after allocation. --- v2: introduce new "bool consider_clear_status" arg v6: dont pass a NULL resv when calling amdgpu_fill_buffer from amdgpu_bo_create --- Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com> Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> 
It's doing the same thing as amdgpu_fill_buffer(src_data=0), so drop it.

The only caveat is that amdgpu_res_cleared() return value is only valid
right after allocation.

---
v2: introduce new "bool consider_clear_status" arg
v6: dont pass a NULL resv when calling amdgpu_fill_buffer from
    amdgpu_bo_create
---

Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
drm/amdgpu: pass all the sdma scheds to amdgpu_mman 2026-04-17T19:41:12+00:00 Pierre-Eric Pelloux-Prayer pierre-eric.pelloux-prayer@amd.com 2025-11-18T14:47:37+00:00 01c836788b373329cd6dfea6508d80314eb9bae5 This will allow the use of all of them for clear/fill buffer operations. Since drm_sched_entity_init requires a scheduler array, we store schedulers rather than rings. For the few places that need access to a ring, we can get it from the sched using container_of. Since the code is the same for all sdma versions, add a new helper amdgpu_sdma_set_buffer_funcs_scheds to set buffer_funcs_scheds based on the number of sdma instances. Note: the new sched array is identical to the amdgpu_vm_manager one. These 2 could be merged. Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com> Acked-by: Felix Kuehling <felix.kuehling@amd.com> Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> 
This will allow the use of all of them for clear/fill buffer
operations.
Since drm_sched_entity_init requires a scheduler array, we
store schedulers rather than rings. For the few places that need
access to a ring, we can get it from the sched using container_of.

Since the code is the same for all sdma versions, add a new
helper amdgpu_sdma_set_buffer_funcs_scheds to set buffer_funcs_scheds
based on the number of sdma instances.

Note: the new sched array is identical to the amdgpu_vm_manager one.
These 2 could be merged.

Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
Acked-by: Felix Kuehling <felix.kuehling@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
drm/amdgpu: Add host driver reserved-region 2026-04-03T17:50:01+00:00 Lijo Lazar lijo.lazar@amd.com 2026-03-25T13:10:24+00:00 4c616e8446b916d8888415c76a91b36a00f94f79 Use reserve region helpers for initializing/reserving host driver reserved region in virtualization environment. Signed-off-by: Lijo Lazar <lijo.lazar@amd.com> Reviewed-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> 
Use reserve region helpers for initializing/reserving host driver
reserved region in virtualization environment.

Signed-off-by: Lijo Lazar <lijo.lazar@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
drm/amdgpu: Add fw vram usage reserve-region 2026-04-03T17:49:58+00:00 Lijo Lazar lijo.lazar@amd.com 2026-03-25T13:02:25+00:00 daaf24d1fc538fc713ffc4a84949af0d92f06fb4 Use reserve region helpers for initializing/reserving firmware usage region in virtualized environments. Signed-off-by: Lijo Lazar <lijo.lazar@amd.com> Reviewed-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> 
Use reserve region helpers for initializing/reserving firmware usage
region in virtualized environments.

Signed-off-by: Lijo Lazar <lijo.lazar@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
drm/amdgpu: Add firmware extended reserve-region 2026-04-03T17:49:49+00:00 Lijo Lazar lijo.lazar@amd.com 2026-03-25T11:50:11+00:00 14a517e37a575da79681c9b5e3b39d3755cbd94d Use reserve region helpers for initializing/reserving extended firmware reservation area. Signed-off-by: Lijo Lazar <lijo.lazar@amd.com> Reviewed-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> 
Use reserve region helpers for initializing/reserving extended firmware
reservation area.

Signed-off-by: Lijo Lazar <lijo.lazar@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
drm/amdgpu: Add fw_reserved reserve-region 2026-04-03T17:49:47+00:00 Lijo Lazar lijo.lazar@amd.com 2026-03-25T11:47:10+00:00 b2155aaef0eae56ff1a3583dff38e7b92e99f8ed Use reserve region helpers for initializing/reserving fw_reserved region. Signed-off-by: Lijo Lazar <lijo.lazar@amd.com> Reviewed-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> 
Use reserve region helpers for initializing/reserving fw_reserved region.

Signed-off-by: Lijo Lazar <lijo.lazar@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
drm/amdgpu: Add stolen_reserved reserve-region 2026-04-03T17:49:43+00:00 Lijo Lazar lijo.lazar@amd.com 2026-03-25T11:38:45+00:00 272a9c8f6f711c283f18aa954e54ede7ed32bdd8 Use reserve region helpers for initializing/reserving stolen_reserved region. Signed-off-by: Lijo Lazar <lijo.lazar@amd.com> Reviewed-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> 
Use reserve region helpers for initializing/reserving stolen_reserved region.

Signed-off-by: Lijo Lazar <lijo.lazar@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>