kernel/linux.git/drivers/gpu/drm/drm_internal.h, branch v6.12.81

drm/framebuffer: Acquire internal references on GEM handles

2025-07-17T16:37:12+00:00

commit f6bfc9afc7510cb5e6fbe0a17c507917b0120280 upstream. Acquire GEM handles in drm_framebuffer_init() and release them in the corresponding drm_framebuffer_cleanup(). Ties the handle's lifetime to the framebuffer. Not all GEM buffer objects have GEM handles. If not set, no refcounting takes place. This is the case for some fbdev emulation. This is not a problem as these GEM objects do not use dma-bufs and drivers will not release them while fbdev emulation is running. Framebuffer flags keep a bit per color plane of which the framebuffer holds a GEM handle reference. As all drivers use drm_framebuffer_init(), they will now all hold dma-buf references as fixed in commit 5307dce878d4 ("drm/gem: Acquire references on GEM handles for framebuffers"). In the GEM framebuffer helpers, restore the original ref counting on buffer objects. As the helpers for handle refcounting are now no longer called from outside the DRM core, unexport the symbols. v3: - don't mix internal flags with mode flags (Christian) v2: - track framebuffer handle refs by flag - drop gma500 cleanup (Christian) Signed-off-by: Thomas Zimmermann Fixes: 5307dce878d4 ("drm/gem: Acquire references on GEM handles for framebuffers") Reported-by: Bert Karwatzki Closes: https://lore.kernel.org/dri-devel/20250703115915.3096-1-spasswolf@web.de/ Tested-by: Bert Karwatzki Tested-by: Mario Limonciello Tested-by: Borislav Petkov (AMD) Cc: Thomas Zimmermann Cc: Anusha Srivatsa Cc: Christian König Cc: Maarten Lankhorst Cc: Maxime Ripard Cc: Sumit Semwal Cc: "Christian König" Cc: linux-media@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: linaro-mm-sig@lists.linaro.org Cc: Reviewed-by: Christian König Link: https://lore.kernel.org/r/20250707131224.249496-1-tzimmermann@suse.de Signed-off-by: Greg Kroah-Hartman

drm/gem: Acquire references on GEM handles for framebuffers

2025-07-17T16:37:11+00:00

commit 5307dce878d4126e1b375587318955bd019c3741 upstream. A GEM handle can be released while the GEM buffer object is attached to a DRM framebuffer. This leads to the release of the dma-buf backing the buffer object, if any. [1] Trying to use the framebuffer in further mode-setting operations leads to a segmentation fault. Most easily happens with driver that use shadow planes for vmap-ing the dma-buf during a page flip. An example is shown below. [ 156.791968] ------------[ cut here ]------------ [ 156.796830] WARNING: CPU: 2 PID: 2255 at drivers/dma-buf/dma-buf.c:1527 dma_buf_vmap+0x224/0x430 [...] [ 156.942028] RIP: 0010:dma_buf_vmap+0x224/0x430 [ 157.043420] Call Trace: [ 157.045898] [ 157.048030] ? show_trace_log_lvl+0x1af/0x2c0 [ 157.052436] ? show_trace_log_lvl+0x1af/0x2c0 [ 157.056836] ? show_trace_log_lvl+0x1af/0x2c0 [ 157.061253] ? drm_gem_shmem_vmap+0x74/0x710 [ 157.065567] ? dma_buf_vmap+0x224/0x430 [ 157.069446] ? __warn.cold+0x58/0xe4 [ 157.073061] ? dma_buf_vmap+0x224/0x430 [ 157.077111] ? report_bug+0x1dd/0x390 [ 157.080842] ? handle_bug+0x5e/0xa0 [ 157.084389] ? exc_invalid_op+0x14/0x50 [ 157.088291] ? asm_exc_invalid_op+0x16/0x20 [ 157.092548] ? dma_buf_vmap+0x224/0x430 [ 157.096663] ? dma_resv_get_singleton+0x6d/0x230 [ 157.101341] ? __pfx_dma_buf_vmap+0x10/0x10 [ 157.105588] ? __pfx_dma_resv_get_singleton+0x10/0x10 [ 157.110697] drm_gem_shmem_vmap+0x74/0x710 [ 157.114866] drm_gem_vmap+0xa9/0x1b0 [ 157.118763] drm_gem_vmap_unlocked+0x46/0xa0 [ 157.123086] drm_gem_fb_vmap+0xab/0x300 [ 157.126979] drm_atomic_helper_prepare_planes.part.0+0x487/0xb10 [ 157.133032] ? lockdep_init_map_type+0x19d/0x880 [ 157.137701] drm_atomic_helper_commit+0x13d/0x2e0 [ 157.142671] ? drm_atomic_nonblocking_commit+0xa0/0x180 [ 157.147988] drm_mode_atomic_ioctl+0x766/0xe40 [...] [ 157.346424] ---[ end trace 0000000000000000 ]--- Acquiring GEM handles for the framebuffer's GEM buffer objects prevents this from happening. The framebuffer's cleanup later puts the handle references. Commit 1a148af06000 ("drm/gem-shmem: Use dma_buf from GEM object instance") triggers the segmentation fault easily by using the dma-buf field more widely. The underlying issue with reference counting has been present before. v2: - acquire the handle instead of the BO (Christian) - fix comment style (Christian) - drop the Fixes tag (Christian) - rename err_ gotos - add missing Link tag Suggested-by: Christian König Signed-off-by: Thomas Zimmermann Link: https://elixir.bootlin.com/linux/v6.15/source/drivers/gpu/drm/drm_gem.c#L241 # [1] Cc: Thomas Zimmermann Cc: Anusha Srivatsa Cc: Christian König Cc: Maarten Lankhorst Cc: Maxime Ripard Cc: Sumit Semwal Cc: "Christian König" Cc: linux-media@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: linaro-mm-sig@lists.linaro.org Cc: Reviewed-by: Christian König Link: https://lore.kernel.org/r/20250630084001.293053-1-tzimmermann@suse.de Signed-off-by: Greg Kroah-Hartman

accel: Use XArray instead of IDR for minors

2024-08-26T15:06:22+00:00

Accel minor management is based on DRM (and is also using struct drm_minor internally), since DRM is using XArray for minors, it makes sense to also convert accel. As the two implementations are identical (only difference being the underlying xarray), move the accel_minor_* functionality to DRM. Signed-off-by: Michał Winiarski Acked-by: James Zhu Acked-by: Christian König Link: https://patchwork.freedesktop.org/patch/msgid/20240823163048.2676257-3-michal.winiarski@intel.com Signed-off-by: Christian König

drm: Remove struct drm_driver.lastclose

2024-08-13T14:21:12+00:00

The lastclose callback in struct drm_driver is unused. Remove it. Also update documentation. v2: - update to use drm_lastclose() - fix typo in documentation Signed-off-by: Thomas Zimmermann Reviewed-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20240812083000.337744-9-tzimmermann@suse.de

drm/edid: move all internal declarations to drm_crtc_internal.h

2024-04-17T13:11:17+00:00

The declarations for internal EDID functions are a bit scattered. Put them all in drm_crtc_internal.h. Reviewed-by: Thomas Zimmermann Link: https://patchwork.freedesktop.org/patch/msgid/9ae137ea51f9cc2ccb3899b0acda553e6a8ce2db.1713259151.git.jani.nikula@intel.com Signed-off-by: Jani Nikula

drm/gem: Acquire reservation lock in drm_gem_{pin/unpin}()

2024-03-11T12:33:50+00:00

Acquire the buffer object's reservation lock in drm_gem_pin() and remove locking the drivers' GEM callbacks where necessary. Same for unpin(). DRM drivers and memory managers modified by this patch will now have correct dma-buf locking semantics: the caller is responsible for holding the reservation lock when calling the pin or unpin callback. DRM drivers and memory managers that are not modified will now be protected against concurent invocation of their pin and unpin callbacks. PRIME does not implement struct dma_buf_ops.pin, which requires the caller to hold the reservation lock. It does implement struct dma_buf_ops.attach, which requires to callee to acquire the reservation lock. The PRIME code uses drm_gem_pin(), so locks are now taken as specified. Same for unpin and detach. The patch harmonizes GEM pin and unpin to have non-interruptible reservation locking across all drivers, as is already the case for vmap and vunmap. This affects gem-shmem, gem-vram, loongson, qxl and radeon. Signed-off-by: Thomas Zimmermann Reviewed-by: Christian König Reviewed-by: Zack Rusin Reviewed-by: Dmitry Osipenko Tested-by: Dmitry Osipenko # virtio-gpu Link: https://patchwork.freedesktop.org/patch/msgid/20240227113853.8464-10-tzimmermann@suse.de

drm: add missing header guards to drm_internal.h

2024-03-07T15:17:25+00:00

Including the file twice leads to errors. Reviewed-by: Thomas Zimmermann Signed-off-by: Jani Nikula Link: https://patchwork.freedesktop.org/patch/msgid/6e744360513e581765147ea7b1e693f4bffe03a9.1709749576.git.jani.nikula@intel.com

drm: Remove source code for non-KMS drivers

2023-12-06T09:08:37+00:00

Remove all remaining source code for non-KMS drivers. These drivers have been removed in v6.3 and won't comeback. Signed-off-by: Thomas Zimmermann Reviewed-by: David Airlie Reviewed-by: Daniel Vetter Acked-by: Alex Deucher Link: https://patchwork.freedesktop.org/patch/msgid/20231122122449.11588-13-tzimmermann@suse.de

drm: Remove the legacy DRM_IOCTL_MODESET_CTL ioctl

2023-12-06T09:08:24+00:00

DRM drivers with user-space mode setting have been removed in Linux v6.3. [1] Now remove the ioctl entry points for these drivers. Invoking any of the ioctl ops will unconditionally return -EINVAL to user space. Invoking DRM_IOCTL_MODESET_CTL is different from the other legacy ioctl ops as it returns 0 even without CONFIG_DRM_LEGACY set. From the original commit 29935554b384 ("drm: Disallow DRM_IOCTL_MODESET_CTL for KMS drivers") it is not apparent how or why the operation differs from the others. It is likely just an oversight in commit 61ae227032e7 ("drm: allow removal of legacy codepaths (v4.1)"), which allowed disabling leagacy ioctls in the first place. Still keep this removal separate from the other ioctls to allow an easy revert, if necessary. Signed-off-by: Thomas Zimmermann Link: https://patchwork.freedesktop.org/series/111602/ # [1] Reviewed-by: David Airlie Reviewed-by: Daniel Vetter Acked-by: Alex Deucher Link: https://patchwork.freedesktop.org/patch/msgid/20231122122449.11588-10-tzimmermann@suse.de

drm/encoder: register per-encoder debugfs dir

2023-12-04T14:07:29+00:00

Each of connectors and CRTCs used by the DRM device provides debugfs directory, which is used by several standard debugfs files and can further be extended by the driver. Add such generic debugfs directories for encoder. Reviewed-by: Neil Armstrong Acked-by: Maxime Ripard Signed-off-by: Dmitry Baryshkov Link: https://patchwork.freedesktop.org/patch/msgid/20231203115315.1306124-2-dmitry.baryshkov@linaro.org