From: Jason Ekstrand <jason@jlekstrand.net> To: dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org Cc: "Daniel Vetter" <daniel.vetter@ffwll.ch>, "Christian König" <christian.koenig@amd.com>, "Jason Ekstrand" <jason@jlekstrand.net> Subject: [PATCH 4/7] dma-buf: Document DMA_BUF_IOCTL_SYNC Date: Tue, 25 May 2021 16:17:50 -0500 [thread overview] Message-ID: <20210525211753.1086069-5-jason@jlekstrand.net> (raw) In-Reply-To: <20210525211753.1086069-1-jason@jlekstrand.net> This adds a new "DMA Buffer ioctls" section to the dma-buf docs and adds documentation for DMA_BUF_IOCTL_SYNC. Signed-off-by: Jason Ekstrand <jason@jlekstrand.net> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Christian König <christian.koenig@amd.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> --- Documentation/driver-api/dma-buf.rst | 8 +++++++ include/uapi/linux/dma-buf.h | 32 +++++++++++++++++++++++++++- 2 files changed, 39 insertions(+), 1 deletion(-) diff --git a/Documentation/driver-api/dma-buf.rst b/Documentation/driver-api/dma-buf.rst index 7f37ec30d9fd7..784f84fe50a5e 100644 --- a/Documentation/driver-api/dma-buf.rst +++ b/Documentation/driver-api/dma-buf.rst @@ -88,6 +88,9 @@ consider though: - The DMA buffer FD is also pollable, see `Implicit Fence Poll Support`_ below for details. +- The DMA buffer FD also supports a few dma-buf-specific ioctls, see + `DMA Buffer ioctls`_ below for details. + Basic Operation and Device DMA Access ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ @@ -106,6 +109,11 @@ Implicit Fence Poll Support .. kernel-doc:: drivers/dma-buf/dma-buf.c :doc: implicit fence polling +DMA Buffer ioctls +~~~~~~~~~~~~~~~~~ + +.. kernel-doc:: include/uapi/linux/dma-buf.h + Kernel Functions and Structures Reference ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ diff --git a/include/uapi/linux/dma-buf.h b/include/uapi/linux/dma-buf.h index 7f30393b92c3b..1f67ced853b14 100644 --- a/include/uapi/linux/dma-buf.h +++ b/include/uapi/linux/dma-buf.h @@ -22,8 +22,38 @@ #include <linux/types.h> -/* begin/end dma-buf functions used for userspace mmap. */ +/** + * struct dma_buf_sync - Synchronize with CPU access. + * + * When a DMA buffer is accessed from the CPU via mmap, it is not always + * possible to guarantee coherency between the CPU-visible map and underlying + * memory. To manage coherency, DMA_BUF_IOCTL_SYNC must be used to bracket + * any CPU access to give the kernel the chance to shuffle memory around if + * needed. + * + * Prior to accessing the map, the client should call DMA_BUF_IOCTL_SYNC + * with DMA_BUF_SYNC_START and the appropriate read/write flags. Once the + * access is complete, the client should call DMA_BUF_IOCTL_SYNC with + * DMA_BUF_SYNC_END and the same read/write flags. + */ struct dma_buf_sync { + /** + * @flags: Set of access flags + * + * - DMA_BUF_SYNC_START: Indicates the start of a map access + * session. + * + * - DMA_BUF_SYNC_END: Indicates the end of a map access session. + * + * - DMA_BUF_SYNC_READ: Indicates that the mapped DMA buffer will + * be read by the client via the CPU map. + * + * - DMA_BUF_SYNC_READ: Indicates that the mapped DMA buffer will + * be written by the client via the CPU map. + * + * - DMA_BUF_SYNC_RW: An alias for DMA_BUF_SYNC_READ | + * DMA_BUF_SYNC_WRITE. + */ __u64 flags; }; -- 2.31.1
WARNING: multiple messages have this Message-ID (diff)
From: Jason Ekstrand <jason@jlekstrand.net> To: dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org Cc: "Daniel Vetter" <daniel.vetter@ffwll.ch>, "Christian König" <christian.koenig@amd.com>, "Sumit Semwal" <sumit.semwal@linaro.org> Subject: [Intel-gfx] [PATCH 4/7] dma-buf: Document DMA_BUF_IOCTL_SYNC Date: Tue, 25 May 2021 16:17:50 -0500 [thread overview] Message-ID: <20210525211753.1086069-5-jason@jlekstrand.net> (raw) In-Reply-To: <20210525211753.1086069-1-jason@jlekstrand.net> This adds a new "DMA Buffer ioctls" section to the dma-buf docs and adds documentation for DMA_BUF_IOCTL_SYNC. Signed-off-by: Jason Ekstrand <jason@jlekstrand.net> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Christian König <christian.koenig@amd.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> --- Documentation/driver-api/dma-buf.rst | 8 +++++++ include/uapi/linux/dma-buf.h | 32 +++++++++++++++++++++++++++- 2 files changed, 39 insertions(+), 1 deletion(-) diff --git a/Documentation/driver-api/dma-buf.rst b/Documentation/driver-api/dma-buf.rst index 7f37ec30d9fd7..784f84fe50a5e 100644 --- a/Documentation/driver-api/dma-buf.rst +++ b/Documentation/driver-api/dma-buf.rst @@ -88,6 +88,9 @@ consider though: - The DMA buffer FD is also pollable, see `Implicit Fence Poll Support`_ below for details. +- The DMA buffer FD also supports a few dma-buf-specific ioctls, see + `DMA Buffer ioctls`_ below for details. + Basic Operation and Device DMA Access ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ @@ -106,6 +109,11 @@ Implicit Fence Poll Support .. kernel-doc:: drivers/dma-buf/dma-buf.c :doc: implicit fence polling +DMA Buffer ioctls +~~~~~~~~~~~~~~~~~ + +.. kernel-doc:: include/uapi/linux/dma-buf.h + Kernel Functions and Structures Reference ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ diff --git a/include/uapi/linux/dma-buf.h b/include/uapi/linux/dma-buf.h index 7f30393b92c3b..1f67ced853b14 100644 --- a/include/uapi/linux/dma-buf.h +++ b/include/uapi/linux/dma-buf.h @@ -22,8 +22,38 @@ #include <linux/types.h> -/* begin/end dma-buf functions used for userspace mmap. */ +/** + * struct dma_buf_sync - Synchronize with CPU access. + * + * When a DMA buffer is accessed from the CPU via mmap, it is not always + * possible to guarantee coherency between the CPU-visible map and underlying + * memory. To manage coherency, DMA_BUF_IOCTL_SYNC must be used to bracket + * any CPU access to give the kernel the chance to shuffle memory around if + * needed. + * + * Prior to accessing the map, the client should call DMA_BUF_IOCTL_SYNC + * with DMA_BUF_SYNC_START and the appropriate read/write flags. Once the + * access is complete, the client should call DMA_BUF_IOCTL_SYNC with + * DMA_BUF_SYNC_END and the same read/write flags. + */ struct dma_buf_sync { + /** + * @flags: Set of access flags + * + * - DMA_BUF_SYNC_START: Indicates the start of a map access + * session. + * + * - DMA_BUF_SYNC_END: Indicates the end of a map access session. + * + * - DMA_BUF_SYNC_READ: Indicates that the mapped DMA buffer will + * be read by the client via the CPU map. + * + * - DMA_BUF_SYNC_READ: Indicates that the mapped DMA buffer will + * be written by the client via the CPU map. + * + * - DMA_BUF_SYNC_RW: An alias for DMA_BUF_SYNC_READ | + * DMA_BUF_SYNC_WRITE. + */ __u64 flags; }; -- 2.31.1 _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx
next prev parent reply other threads:[~2021-05-25 21:18 UTC|newest] Thread overview: 68+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-05-25 21:17 [Intel-gfx] [PATCH 0/7] dma-buf: Add an API for exporting sync files (v11) Jason Ekstrand 2021-05-25 21:17 ` Jason Ekstrand 2021-05-25 21:17 ` [Intel-gfx] [PATCH 1/7] dma-buf: Add dma_fence_array_for_each (v2) Jason Ekstrand 2021-05-25 21:17 ` Jason Ekstrand 2021-05-25 21:17 ` [Intel-gfx] [PATCH 2/7] dma-buf: Rename dma_resv helpers from _rcu to _unlocked (v2) Jason Ekstrand 2021-05-25 21:17 ` Jason Ekstrand 2021-05-26 10:57 ` [Intel-gfx] " Christian König 2021-05-26 10:57 ` Christian König 2021-05-27 10:39 ` [Intel-gfx] " Daniel Vetter 2021-05-27 10:39 ` Daniel Vetter 2021-05-27 11:58 ` [Intel-gfx] " Christian König 2021-05-27 11:58 ` Christian König 2021-05-27 13:21 ` [Intel-gfx] " Daniel Vetter 2021-05-27 13:21 ` Daniel Vetter 2021-05-27 13:25 ` [Intel-gfx] " Daniel Vetter 2021-05-27 13:25 ` Daniel Vetter 2021-05-27 13:41 ` [Intel-gfx] " Christian König 2021-05-27 13:41 ` Christian König 2021-06-01 14:34 ` [Intel-gfx] " Daniel Vetter 2021-06-01 14:34 ` Daniel Vetter 2021-06-01 17:27 ` [Intel-gfx] " Christian König 2021-06-01 17:27 ` Christian König 2021-06-01 17:29 ` [Intel-gfx] " Christian König 2021-06-01 17:29 ` Christian König 2021-05-25 21:17 ` [PATCH 3/7] dma-buf: Add dma_resv_get_singleton_unlocked (v5) Jason Ekstrand 2021-05-25 21:17 ` [Intel-gfx] " Jason Ekstrand 2021-05-25 21:17 ` Jason Ekstrand [this message] 2021-05-25 21:17 ` [Intel-gfx] [PATCH 4/7] dma-buf: Document DMA_BUF_IOCTL_SYNC Jason Ekstrand 2021-05-27 10:38 ` Daniel Vetter 2021-05-27 10:38 ` Daniel Vetter 2021-05-27 11:12 ` [Intel-gfx] " Sumit Semwal 2021-05-27 11:12 ` Sumit Semwal 2021-06-10 20:57 ` [Intel-gfx] " Jason Ekstrand 2021-06-10 20:57 ` Jason Ekstrand 2021-05-25 21:17 ` [PATCH 5/7] dma-buf: Add an API for exporting sync files (v11) Jason Ekstrand 2021-05-25 21:17 ` [Intel-gfx] " Jason Ekstrand 2021-05-26 11:02 ` Christian König 2021-05-26 11:02 ` Christian König 2021-05-26 11:31 ` [Intel-gfx] " Daniel Stone 2021-05-26 11:31 ` Daniel Stone 2021-05-26 12:46 ` Christian König 2021-05-26 12:46 ` Christian König 2021-05-26 13:12 ` Daniel Stone 2021-05-26 13:12 ` Daniel Stone 2021-05-26 13:23 ` Christian König 2021-05-26 13:23 ` Christian König 2021-05-27 10:33 ` Daniel Vetter 2021-05-27 10:33 ` Daniel Vetter 2021-05-27 10:48 ` Simon Ser 2021-05-27 10:48 ` Simon Ser 2021-05-27 12:01 ` Christian König 2021-05-27 12:01 ` Christian König [not found] ` <CAOFGe95Zdn8P3=sOT0HkE9_+ac70g36LxpmLOyR2bKTTeS-xvQ@mail.gmail.com> [not found] ` <fef50d81-399a-af09-1d13-de4db1b3fab8@amd.com> 2021-05-27 15:39 ` Jason Ekstrand 2021-05-27 15:39 ` Jason Ekstrand 2021-05-25 21:17 ` [PATCH 6/7] RFC: dma-buf: Add an extra fence to dma_resv_get_singleton_unlocked Jason Ekstrand 2021-05-25 21:17 ` [Intel-gfx] " Jason Ekstrand 2021-05-25 21:17 ` [PATCH 7/7] RFC: dma-buf: Add an API for importing sync files (v7) Jason Ekstrand 2021-05-25 21:17 ` [Intel-gfx] " Jason Ekstrand 2021-05-26 17:09 ` Daniel Vetter 2021-05-26 17:09 ` Daniel Vetter 2021-05-25 21:44 ` [Intel-gfx] ✗ Fi.CI.CHECKPATCH: warning for dma-buf: Add an API for exporting sync files (v11) Patchwork 2021-05-25 21:46 ` [Intel-gfx] ✗ Fi.CI.SPARSE: " Patchwork 2021-05-25 22:14 ` [Intel-gfx] ✓ Fi.CI.BAT: success " Patchwork 2021-05-26 4:20 ` [Intel-gfx] ✗ Fi.CI.IGT: failure " Patchwork 2021-06-10 20:10 ` [Intel-gfx] [PATCH 0/7] " Chia-I Wu 2021-06-10 20:10 ` Chia-I Wu 2021-06-10 20:26 ` [Intel-gfx] " Jason Ekstrand 2021-06-10 20:26 ` Jason Ekstrand
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