kernel/linux.git/drivers/gpu/drm/drm_gpusvm.c, branch linux-7.0.y

drm/gpusvm: Fix unbalanced unlock in drm_gpusvm_scan_mm()

2026-05-23T11:08:41+00:00

[ Upstream commit d287dee565c3c32e1ed76ec1847af46809c29b90 ] There is a unbalanced lock/unlock to gpusvm notifier lock: [ 931.045868] ===================================== [ 931.046509] WARNING: bad unlock balance detected! [ 931.047149] 6.19.0-rc6+xe-**************** #9 Tainted: G U [ 931.048150] ------------------------------------- [ 931.048790] kworker/u5:0/51 is trying to release lock (&gpusvm->notifier_lock) at: [ 931.049801] [] drm_gpusvm_scan_mm+0x188/0x460 [drm_gpusvm_helper] [ 931.050802] but there are no more locks to release! [ 931.051463] The drm_gpusvm_notifier_unlock() sits under err_free label and the first jump to err_free is just before calling the drm_gpusvm_notifier_lock() causing unbalanced unlock. Fixes: f1d08a586482 ("drm/gpusvm: Introduce a function to scan the current migration state") Signed-off-by: Maciej Patelczyk Cc: Thomas Hellström Reviewed-by: Matthew Brost Signed-off-by: Matthew Brost Link: https://patch.msgid.link/20260209123433.1271053-1-maciej.patelczyk@intel.com Signed-off-by: Sasha Levin

drm/gpusvm: Force unmapping on error in drm_gpusvm_get_pages

2026-05-17T15:16:23+00:00

commit 556dba95473900073a6c03121361c11f646dc551 upstream. drm_gpusvm_get_pages() only sets the local flags prior to committing the pages. If an error occurs mid-mapping, has_dma_mapping will be clear, causing the unmap function to skip unmapping pages that were successfully mapped before the error. Fix this by forcibly setting has_dma_mapping in the error path to ensure all previously mapped pages are properly unmapped. Fixes: 99624bdff867 ("drm/gpusvm: Add support for GPU Shared Virtual Memory") Cc: stable@vger.kernel.org Signed-off-by: Matthew Brost Reviewed-by: Francois Dugast Link: https://patch.msgid.link/20260130194928.3255613-2-matthew.brost@intel.com Signed-off-by: Greg Kroah-Hartman

drm/gpusvm: Allow device pages to be mapped in mixed mappings after system pages

2026-05-17T15:16:23+00:00

commit ec49857ad181f2a68a3bea15422f2936ff366d47 upstream. The current code rejects device mappings whenever system pages have already been encountered. This is not the intended behavior when allow_mixed is set. Relax the restriction by permitting a single pagemap to be selected when allow_mixed is enabled, even if system pages were found earlier. Fixes: bce13d6ecd6c ("drm/gpusvm, drm/xe: Allow mixed mappings for userptr") Cc: stable@vger.kernel.org Signed-off-by: Matthew Brost Reviewed-by: Francois Dugast Link: https://patch.msgid.link/20260130194928.3255613-3-matthew.brost@intel.com Signed-off-by: Greg Kroah-Hartman

drm/gpusvm: Fix drm_gpusvm_pages_valid_unlocked() kernel-doc

2026-02-24T17:25:36+00:00

The kernel-doc for drm_gpusvm_pages_valid_unlocked() was stale and still referenced old range-based arguments and naming. Update the documentation to match the current function arguments and signature. Signed-off-by: Matthew Brost Reviewed-by: Maarten Lankhorst Link: https://patch.msgid.link/20260219205029.1011336-1-matthew.brost@intel.com

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

drm/pagemap: pass pagemap_addr by reference

2026-02-18T00:39:44+00:00

Passing a structure by value into a function is sometimes problematic, for a number of reasons. Of of these is a warning from the 32-bit arm compiler: drivers/gpu/drm/drm_gpusvm.c: In function '__drm_gpusvm_unmap_pages': drivers/gpu/drm/drm_gpusvm.c:1152:33: note: parameter passing for argument of type 'struct drm_pagemap_addr' changed in GCC 9.1 1152 | dpagemap->ops->device_unmap(dpagemap, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 1153 | dev, *addr); | ~~~~~~~~~~~ This particular problem is harmless since we are not mixing compiler versions inside of the compiler. However, passing this by reference avoids the warning along with providing slightly better calling conventions as it avoids an extra copy on the stack. Fixes: 75af93b3f5d0 ("drm/pagemap, drm/xe: Support destination migration over interconnect") Fixes: 2df55d9e66a2 ("drm/xe: Support pcie p2p dma as a fast interconnect") Signed-off-by: Arnd Bergmann Reviewed-by: Thomas Hellström Signed-off-by: Thomas Hellström Link: https://patch.msgid.link/20260216134644.1025365-1-arnd@kernel.org Acked-by: Maarten Lankhorst (cherry picked from commit 95162db0208aee122d10ac1342fe97a1721cd258) Signed-off-by: Rodrigo Vivi

drm/gpusvm: Introduce a function to scan the current migration state

2025-12-23T09:00:48+00:00

With multi-device we are much more likely to have multiple drm-gpusvm ranges pointing to the same struct mm range. To avoid calling into drm_pagemap_populate_mm(), which is always very costly, introduce a much less costly drm_gpusvm function, drm_gpusvm_scan_mm() to scan the current migration state. The device fault-handler and prefetcher can use this function to determine whether migration is really necessary. There are a couple of performance improvements that can be done for this function if it turns out to be too costly. Those are documented in the code. v3: - New patch. Signed-off-by: Thomas Hellström Reviewed-by: Matthew Brost Reviewed-by: Himal Prasad Ghimiray Acked-by: Maarten Lankhorst # For merging through drm-xe. Link: https://patch.msgid.link/20251219113320.183860-21-thomas.hellstrom@linux.intel.com

drm/pagemap, drm/xe: Add refcounting to struct drm_pagemap

2025-12-23T08:35:53+00:00

With the end goal of being able to free unused pagemaps and allocate them on demand, add a refcount to struct drm_pagemap, remove the xe embedded drm_pagemap, allocating and freeing it explicitly. v2: - Make the drm_pagemap pointer in drm_gpusvm_pages reference-counted. v3: - Call drm_pagemap_get() before drm_pagemap_put() in drm_gpusvm_pages (Himal Prasad Ghimiray) Signed-off-by: Thomas Hellström Reviewed-by: Matthew Brost #v1 Reviewed-by: Himal Prasad Ghimiray Acked-by: Maarten Lankhorst # For merging through drm-xe. Link: https://patch.msgid.link/20251219113320.183860-5-thomas.hellstrom@linux.intel.com

drm/gpusvm: Limit the number of retries in drm_gpusvm_get_pages

2025-11-26T18:21:45+00:00

drm_gpusvm_get_pages should not be allowed to retry forever, cap the time spent in the function to HMM_RANGE_DEFAULT_TIMEOUT has this is essentially a wrapper around hmm_range_fault. Signed-off-by: Matthew Brost Reviewed-by: Himal Prasad Ghimiray Link: https://patch.msgid.link/20251122012502.382587-1-matthew.brost@intel.com