kernel/linux.git/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c, branch v6.19.11

drm/amdgpu: clean up the amdgpu_cs_parser_bos

2026-02-26T23:01:35+00:00

[ Upstream commit f025a2b8d93358467b8e8f4b3a617e88c5f02fab ] In low memory conditions, kmalloc can fail. In such conditions unlock the mutex for a clean exit. We do not need to amdgpu_bo_list_put as it's been handled in the amdgpu_cs_parser_fini. Fixes: 737da5363cc0 ("drm/amdgpu: update the functions to use amdgpu version of hmm") Reported-by: kernel test robot Reported-by: Dan Carpenter Closes: https://lore.kernel.org/r/202602030017.7E0xShmH-lkp@intel.com/ Signed-off-by: Sunil Khatri Reviewed-by: Christian König Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin

drm/amdgpu: update the functions to use amdgpu version of hmm

2025-10-13T18:14:36+00:00

At times we need a bo reference for hmm and for that add a new struct amdgpu_hmm_range which will hold an optional bo member and hmm_range. Use amdgpu_hmm_range instead of hmm_range and let the bo as an optional argument for the caller if they want to the bo reference to be taken or they want to handle that explicitly. Signed-off-by: Sunil Khatri Reviewed-by: Christian König Signed-off-by: Alex Deucher

drm/amdgpu: clean up amdgpu hmm range functions

2025-10-13T18:14:28+00:00

Clean up the amdgpu hmm range functions for clearer definition of each. a. Split amdgpu_ttm_tt_get_user_pages_done into two: 1. amdgpu_hmm_range_valid: To check if the user pages are valid and update seq num 2. amdgpu_hmm_range_free: Clean up the hmm range and pfn memory. b. amdgpu_ttm_tt_get_user_pages_done and amdgpu_ttm_tt_discard_user_pages are similar function so remove discard and directly use amdgpu_hmm_range_free to clean up the hmm range and pfn memory. Suggested-by: Christian König Signed-off-by: Sunil Khatri Reviewed-by: Christian König Signed-off-by: Alex Deucher

drm/amdgpu: use user provided hmm_range buffer in amdgpu_ttm_tt_get_user_pages

2025-10-13T18:14:28+00:00

update the amdgpu_ttm_tt_get_user_pages and all dependent function along with it callers to use a user allocated hmm_range buffer instead hmm layer allocates the buffer. This is a need to get hmm_range pointers easily accessible without accessing the bo and that is a requirement for the userqueue to lock the userptrs effectively. Signed-off-by: Sunil Khatri Reviewed-by: Christian König Signed-off-by: Alex Deucher

drm/amdgpu: Fix NULL pointer dereference in VRAM logic for APU devices

2025-10-13T18:14:15+00:00

Previously, APU platforms (and other scenarios with uninitialized VRAM managers) triggered a NULL pointer dereference in `ttm_resource_manager_usage()`. The root cause is not that the `struct ttm_resource_manager *man` pointer itself is NULL, but that `man->bdev` (the backing device pointer within the manager) remains uninitialized (NULL) on APUs—since APUs lack dedicated VRAM and do not fully set up VRAM manager structures. When `ttm_resource_manager_usage()` attempts to acquire `man->bdev->lru_lock`, it dereferences the NULL `man->bdev`, leading to a kernel OOPS. 1. **amdgpu_cs.c**: Extend the existing bandwidth control check in `amdgpu_cs_get_threshold_for_moves()` to include a check for `ttm_resource_manager_used()`. If the manager is not used (uninitialized `bdev`), return 0 for migration thresholds immediately—skipping VRAM-specific logic that would trigger the NULL dereference. 2. **amdgpu_kms.c**: Update the `AMDGPU_INFO_VRAM_USAGE` ioctl and memory info reporting to use a conditional: if the manager is used, return the real VRAM usage; otherwise, return 0. This avoids accessing `man->bdev` when it is NULL. 3. **amdgpu_virt.c**: Modify the vf2pf (virtual function to physical function) data write path. Use `ttm_resource_manager_used()` to check validity: if the manager is usable, calculate `fb_usage` from VRAM usage; otherwise, set `fb_usage` to 0 (APUs have no discrete framebuffer to report). This approach is more robust than APU-specific checks because it: - Works for all scenarios where the VRAM manager is uninitialized (not just APUs), - Aligns with TTM's design by using its native helper function, - Preserves correct behavior for discrete GPUs (which have fully initialized `man->bdev` and pass the `ttm_resource_manager_used()` check). v4: use ttm_resource_manager_used(&adev->mman.vram_mgr.manager) instead of checking the adev->gmc.is_app_apu flag (Christian) Reviewed-by: Christian König Suggested-by: Lijo Lazar Signed-off-by: Jesse Zhang Signed-off-by: Alex Deucher

drm/amdgpu: block CE CS if not explicitely allowed by module option

2025-10-13T18:14:14+00:00

The Constant Engine found on gfx6-gfx10 HW has been a notorious source of problems. RADV never used it in the first place, radeonsi only used it for a few releases around 2017 for gfx6-gfx9 before dropping support for it as well. While investigating another problem I just recently found that submitting to the CE seems to be completely broken on gfx9 for quite a while. Since nobody complained about that problem it most likely means that nobody is using any of the affected radeonsi versions on current Linux kernels any more. So to potentially phase out the support for the CE and eliminate another source of problems block submitting CE IBs unless it is enabled again using a debug flag. Signed-off-by: Christian König Reviewed-by: Alex Deucher Acked-by: Timur Kristóf Signed-off-by: Alex Deucher

drm/amdgpu: remove the redeclaration of variable i

2025-09-25T19:46:35+00:00

Variable "i" has been redeclared as integer later in the function which is wrong and not serving any purpose. Fixes: 899fbde14646 ("drm/amdgpu: replace get_user_pages with HMM mirror helpers") Signed-off-by: Sunil Khatri Reviewed-by: Christian König Signed-off-by: Alex Deucher

drm/amdgpu: use hmm_pfns instead of array of pages

2025-09-23T14:22:31+00:00

we dont need to allocate local array of pages to hold the pages returned by the hmm, instead we could use the hmm_range structure itself to get to hmm_pfn and get the required pages directly. This avoids call to alloc/free quite a lot. Signed-off-by: Sunil Khatri Suggested-by: Christian König Reviewed-by: Christian König Acked-by: Felix Kuehling Signed-off-by: Alex Deucher

drm/amdgpu: reject gang submissions under SRIOV

2025-09-16T21:47:00+00:00

Gang submission means that the kernel driver guarantees that multiple submissions are executed on the HW at the same time on different engines. Background is that those submissions then depend on each other and each can't finish stand alone. SRIOV now uses world switch to preempt submissions on the engines to allow sharing the HW resources between multiple VFs. The problem is now that the SRIOV world switch can't know about such inter dependencies and will cause a timeout if it waits for a partially running gang submission. To conclude SRIOV and gang submissions are fundamentally incompatible at the moment. For now just disable them. Signed-off-by: Christian König Reviewed-by: Alex Deucher Signed-off-by: Alex Deucher

drm/amdgpu: Use (v)memdup_array_user in amdgpu_cs_pass1

2025-09-15T20:51:45+00:00

Replace k(v)malloc_array() + copy_from_user() with (v)memdup_array_user(). This shrinks the source code and improves separation between the kernel and userspace slabs. Signed-off-by: Tvrtko Ursulin Signed-off-by: Alex Deucher