kernel/linux.git/drivers/gpu/drm/tegra/gem.c, branch v6.18.22

Revert "drm/tegra: Use dma_buf from GEM object instance"

2025-08-26T08:41:27+00:00

This reverts commit 482c7e296edc0f594e8869a789a40be53c49bd6a. The dma_buf field in struct drm_gem_object is not stable over the object instance's lifetime. The field becomes NULL when user space releases the final GEM handle on the buffer object. This resulted in a NULL-pointer deref. Workarounds in commit 5307dce878d4 ("drm/gem: Acquire references on GEM handles for framebuffers") and commit f6bfc9afc751 ("drm/framebuffer: Acquire internal references on GEM handles") only solved the problem partially. They especially don't work for buffer objects without a DRM framebuffer associated. Hence, this revert to going back to using .import_attach->dmabuf. Signed-off-by: Thomas Zimmermann Reviewed-by: Simona Vetter Link: https://lore.kernel.org/r/20250715084549.41473-1-tzimmermann@suse.de

drm/tegra: Use dma_buf from GEM object instance

2025-07-07T15:02:28+00:00

Avoid dereferencing struct drm_gem_object.import_attach for the imported dma-buf. The dma_buf field in the GEM object instance refers to the same buffer. Prepares to make import_attach an implementation detail of PRIME. Signed-off-by: Thomas Zimmermann Reviewed-by: Christian König Signed-off-by: Thierry Reding Link: https://lore.kernel.org/r/20250619113100.70292-3-tzimmermann@suse.de

drm/tegra: Test for imported buffers with drm_gem_is_imported()

2025-07-07T15:02:28+00:00

Instead of testing import_attach for imported GEM buffers, invoke drm_gem_is_imported() to do the test. Signed-off-by: Thomas Zimmermann Reviewed-by: Christian König Signed-off-by: Thierry Reding Link: https://lore.kernel.org/r/20250619113100.70292-2-tzimmermann@suse.de

drm/tegra: Remove unneeded include

2025-05-07T15:25:22+00:00

The header file 'tegra_drm.h' is included in gem.c, but this file is already include 'drm.h'. Although there is no harm in including this file again, it is also not necessary. Furthermore, the header file is located under 'include/uapi/drm' so ideally the full path would be used to be explicit. For now, just remove from gem.c. Signed-off-by: Jon Hunter Signed-off-by: Thierry Reding Link: https://lore.kernel.org/r/20250428153435.1013101-1-jonathanh@nvidia.com

module: Convert symbol namespace to string literal

2024-12-02T19:34:44+00:00

Clean up the existing export namespace code along the same lines of commit 33def8498fdd ("treewide: Convert macro and uses of __section(foo) to __section("foo")") and for the same reason, it is not desired for the namespace argument to be a macro expansion itself. Scripted using git grep -l -e MODULE_IMPORT_NS -e EXPORT_SYMBOL_NS | while read file; do awk -i inplace ' /^#define EXPORT_SYMBOL_NS/ { gsub(/__stringify$ns$/, "ns"); print; next; } /^#define MODULE_IMPORT_NS/ { gsub(/__stringify$ns$/, "ns"); print; next; } /MODULE_IMPORT_NS/ { $0 = gensub(/MODULE_IMPORT_NS$([^)]*)$/, "MODULE_IMPORT_NS(\"\\1\")", "g"); } /EXPORT_SYMBOL_NS/ { if ($0 ~ /(EXPORT_SYMBOL_NS[^(]*)$([^,]+),/) { if ($0 !~ /(EXPORT_SYMBOL_NS[^(]*)\(([^,]+), ([^)]+)$/ && $0 !~ /(EXPORT_SYMBOL_NS[^(]*)/ && $0 !~ /^my/) { getline line; gsub(/[[:space:]]*\\$/, ""); gsub(/[[:space:]]/, "", line); $0 = $0 " " line; } $0 = gensub(/(EXPORT_SYMBOL_NS[^(]*)$([^,]+), ([^)]+)$/, "\\1(\\2, \"\\3\")", "g"); } } { print }' $file; done Requested-by: Masahiro Yamada Signed-off-by: Peter Zijlstra (Intel) Link: https://mail.google.com/mail/u/2/#inbox/FMfcgzQXKWgMmjdFwwdsfgxzKpVHWPlc Acked-by: Greg KH Signed-off-by: Linus Torvalds

drm/tegra: gem: Don't attach dma-bufs when not needed

2024-08-29T18:14:29+00:00

The dma-buf import code currently attaches and maps all imported dma-bufs to the drm device to get their sgt for mapping to the directly managed IOMMU domain. In many cases, like for newer chips (Tegra186+), the directly managed IOMMU domain is, however, not used. Mapping to the drm device can also cause issues e.g. with swiotlb since it is not a real device. To improve the situation, only attach and map imported dma-bufs when required. Signed-off-by: Mikko Perttunen Signed-off-by: Thierry Reding Link: https://patchwork.freedesktop.org/patch/msgid/20240424051335.2872574-2-cyndis@kapsi.fi

drm/tegra: gem: Open code drm_prime_gem_destroy

2024-08-29T18:14:29+00:00

Since we aren't using drm_gem_prime_import(_dev), for clarity don't use the corresponding destroy function either. Signed-off-by: Mikko Perttunen Signed-off-by: Thierry Reding Link: https://patchwork.freedesktop.org/patch/msgid/20240424051335.2872574-1-cyndis@kapsi.fi

drm/tegra: gem: Do not return NULL in tegra_bo_mmap()

2023-10-11T20:52:44+00:00

It's confusing for a function to return NULL and ERR_PTR()-encoded error codes on failure. Make sure we only ever return the latter since that's what callers already expect. Reported-by: Sui Jingfeng Reviewed-by: Sui Jingfeng Signed-off-by: Thierry Reding Link: https://patchwork.freedesktop.org/patch/msgid/ZSVuVcqdGfGtQIQj@orome.fritz.box

drm/tegra: Zero-initialize iosys_map

2023-10-11T20:52:44+00:00

UBSAN reports an invalid load for bool, as the iosys_map is read later without being initialized. Zero-initialize it to avoid this. Reported-by: Ashish Mhetre Signed-off-by: Mikko Perttunen Signed-off-by: Thierry Reding Link: https://patchwork.freedesktop.org/patch/msgid/20230901115910.701518-2-cyndis@kapsi.fi

drm/tegra: Remove surplus else after return

2023-10-11T20:52:43+00:00

else is not generally useful after return Signed-off-by: Sui Jingfeng Signed-off-by: Thierry Reding Link: https://patchwork.freedesktop.org/patch/msgid/20230626143331.640454-2-suijingfeng@loongson.cn