kernel/git/stable/linux-stable.git/drivers/dma-buf, branch linux-6.18.y

dma-buf/udmabuf: skip redundant cpu sync to fix cacheline EEXIST warning

2026-07-18T14:53:33+00:00

commit 504e2b4ab97a51d56d966cd36d0997ad30b65b2d upstream. When CONFIG_DMA_API_DEBUG_SG is enabled, importing a udmabuf into a DRM driver (e.g. amdgpu for video playback in GNOME Videos / Showtime) triggers a spurious warning: DMA-API: amdgpu 0000:03:00.0: cacheline tracking EEXIST, \ overlapping mappings aren't supported WARNING: kernel/dma/debug.c:619 at add_dma_entry+0x473/0x5f0 The call chain is: amdgpu_cs_ioctl -> amdgpu_ttm_backend_bind -> dma_buf_map_attachment -> [udmabuf] map_udmabuf -> get_sg_table -> dma_map_sgtable(dev, sg, direction, 0) // attrs=0 -> debug_dma_map_sg -> add_dma_entry -> EEXIST This happens because udmabuf builds a per-page scatter-gather list via sg_set_folio(). When begin_cpu_udmabuf() has already created an sg table mapped for the misc device, and an importer such as amdgpu maps the same pages for its own device via map_udmabuf(), the DMA debug infrastructure sees two active mappings whose physical addresses share cacheline boundaries and warns about the overlap. The DMA_ATTR_SKIP_CPU_SYNC flag suppresses this check in add_dma_entry() because it signals that no CPU cache maintenance is performed at map/unmap time, making the cacheline overlap harmless. All other major dma-buf exporters already pass this flag: - drm_gem_map_dma_buf() passes DMA_ATTR_SKIP_CPU_SYNC - amdgpu_dma_buf_map() passes DMA_ATTR_SKIP_CPU_SYNC The CPU sync at map/unmap time is also redundant for udmabuf: begin_cpu_udmabuf() and end_cpu_udmabuf() already perform explicit cache synchronization via dma_sync_sgtable_for_cpu/device() when CPU access is requested through the dma-buf interface. Pass DMA_ATTR_SKIP_CPU_SYNC to dma_map_sgtable() and dma_unmap_sgtable() in udmabuf to suppress the spurious warning and skip the redundant sync. Fixes: 284562e1f348 ("udmabuf: implement begin_cpu_access/end_cpu_access hooks") Cc: stable@vger.kernel.org Signed-off-by: Mikhail Gavrilov Acked-by: Vivek Kasireddy Signed-off-by: Vivek Kasireddy Link: https://patch.msgid.link/20260331061657.79983-1-mikhail.v.gavrilov@gmail.com Signed-off-by: Greg Kroah-Hartman

udmabuf: fix DMA direction mismatch in release_udmabuf()

2026-07-18T14:53:33+00:00

commit fb7b1a0ab25a6077d26cb3829e31743972d4f31d upstream. begin_cpu_udmabuf() maps the sg_table with the caller-provided direction (e.g., DMA_TO_DEVICE for a write-only sync), and caches it in ubuf->sg for reuse. However, release_udmabuf() always unmaps this sg_table with a hardcoded DMA_BIDIRECTIONAL, regardless of the direction that was originally used for the mapping. With CONFIG_DMA_API_DEBUG=y this produces: DMA-API: misc udmabuf: device driver frees DMA memory with different direction [device address=0x000000044a123000] [size=4096 bytes] [mapped with DMA_TO_DEVICE] [unmapped with DMA_BIDIRECTIONAL] The issue was found during video playback when GStreamer performed a write-only DMA_BUF_IOCTL_SYNC on a udmabuf. It can be reproduced with CONFIG_DMA_API_DEBUG=y by creating a udmabuf from a memfd, performing a write-only sync (DMA_BUF_SYNC_WRITE without DMA_BUF_SYNC_READ), and closing the file descriptor. Fix this by storing the DMA direction used when the sg_table is first created in begin_cpu_udmabuf(), and passing that same direction to put_sg_table() in release_udmabuf(). Fixes: 284562e1f348 ("udmabuf: implement begin_cpu_access/end_cpu_access hooks") Cc: stable@vger.kernel.org Signed-off-by: Mikhail Gavrilov Reviewed-by: Vivek Kasireddy Signed-off-by: Vivek Kasireddy Link: https://patch.msgid.link/20260314232722.15555-1-mikhail.v.gavrilov@gmail.com Signed-off-by: Greg Kroah-Hartman

dma-fence: Fix safe access wrapper to call timeline name method

2025-10-24T15:56:37+00:00

This commit fixes the wrapper function dma_fence_timeline_name(), that was added for safe access, to actually call the timeline name method of dma_fence_ops. Cc: # v6.17+ Signed-off-by: Akash Goel Fixes: 506aa8b02a8d ("dma-fence: Add safe access helpers and document the rules") Reviewed-by: Tvrtko Ursulin Signed-off-by: Tvrtko Ursulin Link: https://lore.kernel.org/r/20251021160951.1415603-1-akash.goel@arm.com

dma-buf: dma-heap: export declared functions

2025-09-11T09:22:17+00:00

Export the dma-buf heap functions to allow them to be used by the OP-TEE driver. The OP-TEE driver wants to register and manage specific secure DMA heaps with it. Reviewed-by: Sumit Garg Reviewed-by: T.J. Mercier Acked-by: Sumit Semwal Signed-off-by: Jens Wiklander

Merge tag 'drm-next-2025-07-30' of https://gitlab.freedesktop.org/drm/kernel

2025-07-31T02:26:49+00:00

Pull drm updates from Dave Airlie: "Highlights: - Intel xe enable Panthor Lake, started adding WildCat Lake - amdgpu has a bunch of reset improvments along with the usual IP updates - msm got VM_BIND support which is important for vulkan sparse memory - more drm_panic users - gpusvm common code to handle a bunch of core SVM work outside drivers. Detail summary: Changes outside drm subdirectory: - 'shrink_shmem_memory()' for better shmem/hibernate interaction - Rust support infrastructure: - make ETIMEDOUT available - add size constants up to SZ_2G - add DMA coherent allocation bindings - mtd driver for Intel GPU non-volatile storage - i2c designware quirk for Intel xe core: - atomic helpers: tune enable/disable sequences - add task info to wedge API - refactor EDID quirks - connector: move HDR sink to drm_display_info - fourcc: half-float and 32-bit float formats - mode_config: pass format info to simplify dma-buf: - heaps: Give CMA heap a stable name ci: - add device tree validation and kunit displayport: - change AUX DPCD access probe address - add quirk for DPCD probe - add panel replay definitions - backlight control helpers fbdev: - make CONFIG_FIRMWARE_EDID available on all arches fence: - fix UAF issues format-helper: - improve tests gpusvm: - introduce devmem only flag for allocation - add timeslicing support to GPU SVM ttm: - improve eviction sched: - tracing improvements - kunit improvements - memory leak fixes - reset handling improvements color mgmt: - add hardware gamma LUT handling helpers bridge: - add destroy hook - switch to reference counted drm_bridge allocations - tc358767: convert to devm_drm_bridge_alloc - improve CEC handling panel: - switch to reference counter drm_panel allocations - fwnode panel lookup - Huiling hl055fhv028c support - Raspberry Pi 7" 720x1280 support - edp: KDC KD116N3730A05, N160JCE-ELL CMN, N116BCJ-EAK - simple: AUO P238HAN01 - st7701: Winstar wf40eswaa6mnn0 - visionox: rm69299-shift - Renesas R61307, Renesas R69328 support - DJN HX83112B hdmi: - add CEC handling - YUV420 output support xe: - WildCat Lake support - Enable PanthorLake by default - mark BMG as SRIOV capable - update firmware recommendations - Expose media OA units - aux-bux support for non-volatile memory - MTD intel-dg driver for non-volatile memory - Expose fan control and voltage regulator in sysfs - restructure migration for multi-device - Restore GuC submit UAF fix - make GEM shrinker drm managed - SRIOV VF Post-migration recovery of GGTT nodes - W/A additions/reworks - Prefetch support for svm ranges - Don't allocate managed BO for each policy change - HWMON fixes for BMG - Create LRC BO without VM - PCI ID updates - make SLPC debugfs files optional - rework eviction rejection of bound external BOs - consolidate PAT programming logic for pre/post Xe2 - init changes for flicker-free boot - Enable GuC Dynamic Inhibit Context switch i915: - drm_panic support for i915/xe - initial flip queue off by default for LNL/PNL - Wildcat Lake Display support - Support for DSC fractional link bpp - Support for simultaneous Panel Replay and Adaptive sync - Support for PTL+ double buffer LUT - initial PIPEDMC event handling - drm_panel_follower support - DPLL interface renames - allocate struct intel_display dynamically - flip queue preperation - abstract DRAM detection better - avoid GuC scheduling stalls - remove DG1 force probe requirement - fix MEI interrupt handler on RT kernels - use backlight control helpers for eDP - more shared display code refactoring amdgpu: - add userq slot to INFO ioctl - SR-IOV hibernation support - Suspend improvements - Backlight improvements - Use scaling for non-native eDP modes - cleaner shader updates for GC 9.x - Remove fence slab - SDMA fw checks for userq support - RAS updates - DMCUB updates - DP tunneling fixes - Display idle D3 support - Per queue reset improvements - initial smartmux support amdkfd: - enable KFD on loongarch - mtype fix for ext coherent system memory radeon: - CS validation additional GL extensions - drop console lock during suspend/resume - bump driver version msm: - VM BIND support - CI: infrastructure updates - UBWC single source of truth - decouple GPU and KMS support - DP: rework I/O accessors - DPU: SM8750 support - DSI: SM8750 support - GPU: X1-45 support and speedbin support for X1-85 - MDSS: SM8750 support nova: - register! macro improvements - DMA object abstraction - VBIOS parser + fwsec lookup - sysmem flush page support - falcon: generic falcon boot code and HAL - FWSEC-FRTS: fb setup and load/execute ivpu: - Add Wildcat Lake support - Add turbo flag ast: - improve hardware generations implementation imx: - IMX8qxq Display Controller support lima: - Rockchip RK3528 GPU support nouveau: - fence handling cleanup panfrost: - MT8370 support - bo labeling - 64-bit register access qaic: - add RAS support rockchip: - convert inno_hdmi to a bridge rz-du: - add RZ/V2H(P) support - MIPI-DSI DCS support sitronix: - ST7567 support sun4i: - add H616 support tidss: - add TI AM62L support - AM65x OLDI bridge support bochs: - drm panic support vkms: - YUV and R* format support - use faux device vmwgfx: - fence improvements hyperv: - move out of simple - add drm_panic support" * tag 'drm-next-2025-07-30' of https://gitlab.freedesktop.org/drm/kernel: (1479 commits) drm/tidss: oldi: convert to devm_drm_bridge_alloc() API drm/tidss: encoder: convert to devm_drm_bridge_alloc() drm/amdgpu: move reset support type checks into the caller drm/amdgpu/sdma7: re-emit unprocessed state on ring reset drm/amdgpu/sdma6: re-emit unprocessed state on ring reset drm/amdgpu/sdma5.2: re-emit unprocessed state on ring reset drm/amdgpu/sdma5: re-emit unprocessed state on ring reset drm/amdgpu/gfx12: re-emit unprocessed state on ring reset drm/amdgpu/gfx11: re-emit unprocessed state on ring reset drm/amdgpu/gfx10: re-emit unprocessed state on ring reset drm/amdgpu/gfx9.4.3: re-emit unprocessed state on kcq reset drm/amdgpu/gfx9: re-emit unprocessed state on kcq reset drm/amdgpu: Add WARN_ON to the resource clear function drm/amd/pm: Use cached metrics data on SMUv13.0.6 drm/amd/pm: Use cached data for min/max clocks gpu: nova-core: fix bounds check in PmuLookupTableEntry::new drm/amdgpu: Replace HQD terminology with slots naming drm/amdgpu: Add user queue instance count in HW IP info drm/amd/amdgpu: Add helper functions for isp buffers drm/amd/amdgpu: Initialize swnode for ISP MFD device ...

dma-buf: heaps: Give default CMA heap a fixed name

2025-07-09T10:21:40+00:00

The CMA heap's name in devtmpfs can vary depending on how the heap is defined. Its name defaults to "reserved", but if a CMA area is defined in the devicetree, the heap takes on the devicetree node's name, such as "default-pool" or "linux,cma". To simplify naming, unconditionally name it "default_cma_region", but keep a legacy node in place backed by the same underlying allocator for backwards compatibility. Reviewed-by: Maxime Ripard Signed-off-by: Jared Kangas Signed-off-by: Sumit Semwal Link: https://lore.kernel.org/r/20250610131231.1724627-4-jkangas@redhat.com

dma-buf: heaps: Parameterize heap name in __add_cma_heap()

2025-07-09T10:21:39+00:00

Prepare for the introduction of a fixed-name CMA heap by replacing the unused void pointer parameter in __add_cma_heap() with the heap name. Reviewed-by: Maxime Ripard Acked-by: John Stultz Signed-off-by: Jared Kangas Signed-off-by: Sumit Semwal Link: https://lore.kernel.org/r/20250610131231.1724627-3-jkangas@redhat.com

dma-buf: system_heap: No separate allocation for attachment sg_tables

2025-07-09T10:21:39+00:00

struct dma_heap_attachment is a separate allocation from the struct sg_table it contains, but there is no reason for this. Let's use the slab allocator just once instead of twice for dma_heap_attachment. Signed-off-by: T.J. Mercier Reviewed-by: Christian König Signed-off-by: Sumit Semwal Link: https://lore.kernel.org/r/20250417180943.1559755-1-tjmercier@google.com

dma-buf: fix timeout handling in dma_resv_wait_timeout v2

2025-06-30T11:15:44+00:00

Even the kerneldoc says that with a zero timeout the function should not wait for anything, but still return 1 to indicate that the fences are signaled now. Unfortunately that isn't what was implemented, instead of only returning 1 we also waited for at least one jiffies. Fix that by adjusting the handling to what the function is actually documented to do. v2: improve code readability Reported-by: Marek Olšák Reported-by: Lucas Stach Signed-off-by: Christian König Reviewed-by: Lucas Stach Cc: Link: https://lore.kernel.org/r/20250129105841.1806-1-christian.koenig@amd.com

Merge tag 'drm-misc-next-2025-06-19' of https://gitlab.freedesktop.org/drm/misc/kernel into drm-next

2025-06-20T01:34:09+00:00

drm-misc-next for 6.17: UAPI Changes: - Add Task Information for the wedge API Cross-subsystem Changes: Core Changes: - Fix warnings related to export.h - fbdev: Make CONFIG_FIRMWARE_EDID available on all architectures - fence: Fix UAF issues - format-helper: Improve tests Driver Changes: - ivpu: Add turbo flag, Add Wildcat Lake Support - rz-du: Improve MIPI-DSI Support - vmwgfx: fence improvement Signed-off-by: Dave Airlie From: Maxime Ripard Link: https://lore.kernel.org/r/20250619-perfect-industrious-whippet-8ed3db@houat