From: Sergey Senozhatsky sergey.senozhatsky@gmail.com
The patch partially reverts some of the UAPI bits of the buffer cache management hints. Namely, the queue consistency (memory coherency) user-space hint because, as it turned out, the kernel implementation of this feature was misusing DMA_ATTR_NON_CONSISTENT.
The patch revers both kernel and user space parts: removes the DMA consistency attr functions, rollbacks changes to v4l2_requestbuffers, v4l2_create_buffers structures and corresponding UAPI functions (plus compat32 layer) and cleanups the documentation.
Signed-off-by: Christoph Hellwig hch@lst.de Signed-off-by: Sergey Senozhatsky sergey.senozhatsky@gmail.com Signed-off-by: Christoph Hellwig hch@lst.de --- .../userspace-api/media/v4l/buffer.rst | 17 ------- .../media/v4l/vidioc-create-bufs.rst | 6 +-- .../media/v4l/vidioc-reqbufs.rst | 12 +---- .../media/common/videobuf2/videobuf2-core.c | 46 +++---------------- .../common/videobuf2/videobuf2-dma-contig.c | 19 -------- .../media/common/videobuf2/videobuf2-dma-sg.c | 3 +- .../media/common/videobuf2/videobuf2-v4l2.c | 18 +------- drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 10 +--- drivers/media/v4l2-core/v4l2-ioctl.c | 5 +- include/media/videobuf2-core.h | 7 +-- include/uapi/linux/videodev2.h | 13 +----- 11 files changed, 22 insertions(+), 134 deletions(-)
diff --git a/Documentation/userspace-api/media/v4l/buffer.rst b/Documentation/userspace-api/media/v4l/buffer.rst index 57e752aaf414a7..2044ed13cd9d7d 100644 --- a/Documentation/userspace-api/media/v4l/buffer.rst +++ b/Documentation/userspace-api/media/v4l/buffer.rst @@ -701,23 +701,6 @@ Memory Consistency Flags :stub-columns: 0 :widths: 3 1 4
- * .. _`V4L2-FLAG-MEMORY-NON-CONSISTENT`: - - - ``V4L2_FLAG_MEMORY_NON_CONSISTENT`` - - 0x00000001 - - A buffer is allocated either in consistent (it will be automatically - coherent between the CPU and the bus) or non-consistent memory. The - latter can provide performance gains, for instance the CPU cache - sync/flush operations can be avoided if the buffer is accessed by the - corresponding device only and the CPU does not read/write to/from that - buffer. However, this requires extra care from the driver -- it must - guarantee memory consistency by issuing a cache flush/sync when - consistency is needed. If this flag is set V4L2 will attempt to - allocate the buffer in non-consistent memory. The flag takes effect - only if the buffer is used for :ref:`memory mapping <mmap>` I/O and the - queue reports the :ref:`V4L2_BUF_CAP_SUPPORTS_MMAP_CACHE_HINTS - <V4L2-BUF-CAP-SUPPORTS-MMAP-CACHE-HINTS>` capability. - .. c:type:: v4l2_memory
enum v4l2_memory diff --git a/Documentation/userspace-api/media/v4l/vidioc-create-bufs.rst b/Documentation/userspace-api/media/v4l/vidioc-create-bufs.rst index f2a702870fadc1..12cf6b44f414f7 100644 --- a/Documentation/userspace-api/media/v4l/vidioc-create-bufs.rst +++ b/Documentation/userspace-api/media/v4l/vidioc-create-bufs.rst @@ -120,13 +120,9 @@ than the number requested. If you want to just query the capabilities without making any other changes, then set ``count`` to 0, ``memory`` to ``V4L2_MEMORY_MMAP`` and ``format.type`` to the buffer type. - * - __u32 - - ``flags`` - - Specifies additional buffer management attributes. - See :ref:`memory-flags`.
* - __u32 - - ``reserved``\ [6] + - ``reserved``\ [7] - A place holder for future extensions. Drivers and applications must set the array to zero.
diff --git a/Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst b/Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst index 75d894d9c36c42..0e3e2fde65e850 100644 --- a/Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst +++ b/Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst @@ -112,17 +112,10 @@ aborting or finishing any DMA in progress, an implicit ``V4L2_MEMORY_MMAP`` and ``type`` set to the buffer type. This will free any previously allocated buffers, so this is typically something that will be done at the start of the application. - * - union { - - (anonymous) - * - __u32 - - ``flags`` - - Specifies additional buffer management attributes. - See :ref:`memory-flags`. * - __u32 - ``reserved``\ [1] - - Kept for backwards compatibility. Use ``flags`` instead. - * - } - - + - A place holder for future extensions. Drivers and applications + must set the array to zero.
.. tabularcolumns:: |p{6.1cm}|p{2.2cm}|p{8.7cm}|
@@ -169,7 +162,6 @@ aborting or finishing any DMA in progress, an implicit - This capability is set by the driver to indicate that the queue supports cache and memory management hints. However, it's only valid when the queue is used for :ref:`memory mapping <mmap>` streaming I/O. See - :ref:`V4L2_FLAG_MEMORY_NON_CONSISTENT <V4L2-FLAG-MEMORY-NON-CONSISTENT>`, :ref:`V4L2_BUF_FLAG_NO_CACHE_INVALIDATE <V4L2-BUF-FLAG-NO-CACHE-INVALIDATE>` and :ref:`V4L2_BUF_FLAG_NO_CACHE_CLEAN <V4L2-BUF-FLAG-NO-CACHE-CLEAN>`.
diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c index f544d3393e9d6b..4eab6d81cce170 100644 --- a/drivers/media/common/videobuf2/videobuf2-core.c +++ b/drivers/media/common/videobuf2/videobuf2-core.c @@ -721,39 +721,14 @@ int vb2_verify_memory_type(struct vb2_queue *q, } EXPORT_SYMBOL(vb2_verify_memory_type);
-static void set_queue_consistency(struct vb2_queue *q, bool consistent_mem) -{ - q->dma_attrs &= ~DMA_ATTR_NON_CONSISTENT; - - if (!vb2_queue_allows_cache_hints(q)) - return; - if (!consistent_mem) - q->dma_attrs |= DMA_ATTR_NON_CONSISTENT; -} - -static bool verify_consistency_attr(struct vb2_queue *q, bool consistent_mem) -{ - bool queue_is_consistent = !(q->dma_attrs & DMA_ATTR_NON_CONSISTENT); - - if (consistent_mem != queue_is_consistent) { - dprintk(q, 1, "memory consistency model mismatch\n"); - return false; - } - return true; -} - int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory, - unsigned int flags, unsigned int *count) + unsigned int *count) { unsigned int num_buffers, allocated_buffers, num_planes = 0; unsigned plane_sizes[VB2_MAX_PLANES] = { }; - bool consistent_mem = true; unsigned int i; int ret;
- if (flags & V4L2_FLAG_MEMORY_NON_CONSISTENT) - consistent_mem = false; - if (q->streaming) { dprintk(q, 1, "streaming active\n"); return -EBUSY; @@ -765,8 +740,7 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory, }
if (*count == 0 || q->num_buffers != 0 || - (q->memory != VB2_MEMORY_UNKNOWN && q->memory != memory) || - !verify_consistency_attr(q, consistent_mem)) { + (q->memory != VB2_MEMORY_UNKNOWN && q->memory != memory)) { /* * We already have buffers allocated, so first check if they * are not in use and can be freed. @@ -803,7 +777,6 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory, num_buffers = min_t(unsigned int, num_buffers, VB2_MAX_FRAME); memset(q->alloc_devs, 0, sizeof(q->alloc_devs)); q->memory = memory; - set_queue_consistency(q, consistent_mem);
/* * Ask the driver how many buffers and planes per buffer it requires. @@ -888,18 +861,14 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory, EXPORT_SYMBOL_GPL(vb2_core_reqbufs);
int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory, - unsigned int flags, unsigned int *count, + unsigned int *count, unsigned int requested_planes, const unsigned int requested_sizes[]) { unsigned int num_planes = 0, num_buffers, allocated_buffers; unsigned plane_sizes[VB2_MAX_PLANES] = { }; - bool consistent_mem = true; int ret;
- if (flags & V4L2_FLAG_MEMORY_NON_CONSISTENT) - consistent_mem = false; - if (q->num_buffers == VB2_MAX_FRAME) { dprintk(q, 1, "maximum number of buffers already allocated\n"); return -ENOBUFS; @@ -912,15 +881,12 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory, } memset(q->alloc_devs, 0, sizeof(q->alloc_devs)); q->memory = memory; - set_queue_consistency(q, consistent_mem); q->waiting_for_buffers = !q->is_output; } else { if (q->memory != memory) { dprintk(q, 1, "memory model mismatch\n"); return -EINVAL; } - if (!verify_consistency_attr(q, consistent_mem)) - return -EINVAL; }
num_buffers = min(*count, VB2_MAX_FRAME - q->num_buffers); @@ -2581,7 +2547,7 @@ static int __vb2_init_fileio(struct vb2_queue *q, int read) fileio->memory = VB2_MEMORY_MMAP; fileio->type = q->type; q->fileio = fileio; - ret = vb2_core_reqbufs(q, fileio->memory, 0, &fileio->count); + ret = vb2_core_reqbufs(q, fileio->memory, &fileio->count); if (ret) goto err_kfree;
@@ -2638,7 +2604,7 @@ static int __vb2_init_fileio(struct vb2_queue *q, int read)
err_reqbufs: fileio->count = 0; - vb2_core_reqbufs(q, fileio->memory, 0, &fileio->count); + vb2_core_reqbufs(q, fileio->memory, &fileio->count);
err_kfree: q->fileio = NULL; @@ -2658,7 +2624,7 @@ static int __vb2_cleanup_fileio(struct vb2_queue *q) vb2_core_streamoff(q, q->type); q->fileio = NULL; fileio->count = 0; - vb2_core_reqbufs(q, fileio->memory, 0, &fileio->count); + vb2_core_reqbufs(q, fileio->memory, &fileio->count); kfree(fileio); dprintk(q, 3, "file io emulator closed\n"); } diff --git a/drivers/media/common/videobuf2/videobuf2-dma-contig.c b/drivers/media/common/videobuf2/videobuf2-dma-contig.c index ec3446cc45b8da..7b1b86ec942d7d 100644 --- a/drivers/media/common/videobuf2/videobuf2-dma-contig.c +++ b/drivers/media/common/videobuf2/videobuf2-dma-contig.c @@ -42,11 +42,6 @@ struct vb2_dc_buf { struct dma_buf_attachment *db_attach; };
-static inline bool vb2_dc_buffer_consistent(unsigned long attr) -{ - return !(attr & DMA_ATTR_NON_CONSISTENT); -} - /*********************************************/ /* scatterlist table functions */ /*********************************************/ @@ -341,13 +336,6 @@ static int vb2_dc_dmabuf_ops_begin_cpu_access(struct dma_buf *dbuf, enum dma_data_direction direction) { - struct vb2_dc_buf *buf = dbuf->priv; - struct sg_table *sgt = buf->dma_sgt; - - if (vb2_dc_buffer_consistent(buf->attrs)) - return 0; - - dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir); return 0; }
@@ -355,13 +343,6 @@ static int vb2_dc_dmabuf_ops_end_cpu_access(struct dma_buf *dbuf, enum dma_data_direction direction) { - struct vb2_dc_buf *buf = dbuf->priv; - struct sg_table *sgt = buf->dma_sgt; - - if (vb2_dc_buffer_consistent(buf->attrs)) - return 0; - - dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir); return 0; }
diff --git a/drivers/media/common/videobuf2/videobuf2-dma-sg.c b/drivers/media/common/videobuf2/videobuf2-dma-sg.c index 0a40e00f0d7e5c..a86fce5d8ea8bf 100644 --- a/drivers/media/common/videobuf2/videobuf2-dma-sg.c +++ b/drivers/media/common/videobuf2/videobuf2-dma-sg.c @@ -123,8 +123,7 @@ static void *vb2_dma_sg_alloc(struct device *dev, unsigned long dma_attrs, /* * NOTE: dma-sg allocates memory using the page allocator directly, so * there is no memory consistency guarantee, hence dma-sg ignores DMA - * attributes passed from the upper layer. That means that - * V4L2_FLAG_MEMORY_NON_CONSISTENT has no effect on dma-sg buffers. + * attributes passed from the upper layer. */ buf->pages = kvmalloc_array(buf->num_pages, sizeof(struct page *), GFP_KERNEL | __GFP_ZERO); diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c index 30caad27281e1a..cfe197df970df2 100644 --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c @@ -722,22 +722,12 @@ static void fill_buf_caps(struct vb2_queue *q, u32 *caps) #endif }
-static void clear_consistency_attr(struct vb2_queue *q, - int memory, - unsigned int *flags) -{ - if (!q->allow_cache_hints || memory != V4L2_MEMORY_MMAP) - *flags &= ~V4L2_FLAG_MEMORY_NON_CONSISTENT; -} - int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req) { int ret = vb2_verify_memory_type(q, req->memory, req->type);
fill_buf_caps(q, &req->capabilities); - clear_consistency_attr(q, req->memory, &req->flags); - return ret ? ret : vb2_core_reqbufs(q, req->memory, - req->flags, &req->count); + return ret ? ret : vb2_core_reqbufs(q, req->memory, &req->count); } EXPORT_SYMBOL_GPL(vb2_reqbufs);
@@ -769,7 +759,6 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create) unsigned i;
fill_buf_caps(q, &create->capabilities); - clear_consistency_attr(q, create->memory, &create->flags); create->index = q->num_buffers; if (create->count == 0) return ret != -EBUSY ? ret : 0; @@ -813,7 +802,6 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create) if (requested_sizes[i] == 0) return -EINVAL; return ret ? ret : vb2_core_create_bufs(q, create->memory, - create->flags, &create->count, requested_planes, requested_sizes); @@ -998,12 +986,11 @@ int vb2_ioctl_reqbufs(struct file *file, void *priv, int res = vb2_verify_memory_type(vdev->queue, p->memory, p->type);
fill_buf_caps(vdev->queue, &p->capabilities); - clear_consistency_attr(vdev->queue, p->memory, &p->flags); if (res) return res; if (vb2_queue_is_busy(vdev, file)) return -EBUSY; - res = vb2_core_reqbufs(vdev->queue, p->memory, p->flags, &p->count); + res = vb2_core_reqbufs(vdev->queue, p->memory, &p->count); /* If count == 0, then the owner has released all buffers and he is no longer owner of the queue. Otherwise we have a new owner. */ if (res == 0) @@ -1021,7 +1008,6 @@ int vb2_ioctl_create_bufs(struct file *file, void *priv,
p->index = vdev->queue->num_buffers; fill_buf_caps(vdev->queue, &p->capabilities); - clear_consistency_attr(vdev->queue, p->memory, &p->flags); /* * If count == 0, then just check if memory and type are valid. * Any -EBUSY result from vb2_verify_memory_type can be mapped to 0. diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c index 593bcf6c373502..a99e82ec9ab60d 100644 --- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c +++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c @@ -246,9 +246,6 @@ struct v4l2_format32 { * @memory: buffer memory type * @format: frame format, for which buffers are requested * @capabilities: capabilities of this buffer type. - * @flags: additional buffer management attributes (ignored unless the - * queue has V4L2_BUF_CAP_SUPPORTS_MMAP_CACHE_HINTS capability and - * configured for MMAP streaming I/O). * @reserved: future extensions */ struct v4l2_create_buffers32 { @@ -257,8 +254,7 @@ struct v4l2_create_buffers32 { __u32 memory; /* enum v4l2_memory */ struct v4l2_format32 format; __u32 capabilities; - __u32 flags; - __u32 reserved[6]; + __u32 reserved[7]; };
static int __bufsize_v4l2_format(struct v4l2_format32 __user *p32, u32 *size) @@ -359,8 +355,7 @@ static int get_v4l2_create32(struct v4l2_create_buffers __user *p64, { if (!access_ok(p32, sizeof(*p32)) || copy_in_user(p64, p32, - offsetof(struct v4l2_create_buffers32, format)) || - assign_in_user(&p64->flags, &p32->flags)) + offsetof(struct v4l2_create_buffers32, format))) return -EFAULT; return __get_v4l2_format32(&p64->format, &p32->format, aux_buf, aux_space); @@ -422,7 +417,6 @@ static int put_v4l2_create32(struct v4l2_create_buffers __user *p64, copy_in_user(p32, p64, offsetof(struct v4l2_create_buffers32, format)) || assign_in_user(&p32->capabilities, &p64->capabilities) || - assign_in_user(&p32->flags, &p64->flags) || copy_in_user(p32->reserved, p64->reserved, sizeof(p64->reserved))) return -EFAULT; return __put_v4l2_format32(&p64->format, &p32->format); diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c index 2a22e13a630346..e0520c85a3b725 100644 --- a/drivers/media/v4l2-core/v4l2-ioctl.c +++ b/drivers/media/v4l2-core/v4l2-ioctl.c @@ -2042,6 +2042,9 @@ static int v4l_reqbufs(const struct v4l2_ioctl_ops *ops,
if (ret) return ret; + + CLEAR_AFTER_FIELD(p, capabilities); + return ops->vidioc_reqbufs(file, fh, p); }
@@ -2081,7 +2084,7 @@ static int v4l_create_bufs(const struct v4l2_ioctl_ops *ops, if (ret) return ret;
- CLEAR_AFTER_FIELD(create, flags); + CLEAR_AFTER_FIELD(create, capabilities);
v4l_sanitize_format(&create->format);
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h index 52ef92049073e3..bbb3f26fbde978 100644 --- a/include/media/videobuf2-core.h +++ b/include/media/videobuf2-core.h @@ -744,8 +744,6 @@ void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb); * vb2_core_reqbufs() - Initiate streaming. * @q: pointer to &struct vb2_queue with videobuf2 queue. * @memory: memory type, as defined by &enum vb2_memory. - * @flags: auxiliary queue/buffer management flags. Currently, the only - * used flag is %V4L2_FLAG_MEMORY_NON_CONSISTENT. * @count: requested buffer count. * * Videobuf2 core helper to implement VIDIOC_REQBUF() operation. It is called @@ -770,13 +768,12 @@ void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb); * Return: returns zero on success; an error code otherwise. */ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory, - unsigned int flags, unsigned int *count); + unsigned int *count);
/** * vb2_core_create_bufs() - Allocate buffers and any required auxiliary structs * @q: pointer to &struct vb2_queue with videobuf2 queue. * @memory: memory type, as defined by &enum vb2_memory. - * @flags: auxiliary queue/buffer management flags. * @count: requested buffer count. * @requested_planes: number of planes requested. * @requested_sizes: array with the size of the planes. @@ -794,7 +791,7 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory, * Return: returns zero on success; an error code otherwise. */ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory, - unsigned int flags, unsigned int *count, + unsigned int *count, unsigned int requested_planes, const unsigned int requested_sizes[]);
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h index c7b70ff53bc1dd..235db7754606d6 100644 --- a/include/uapi/linux/videodev2.h +++ b/include/uapi/linux/videodev2.h @@ -191,8 +191,6 @@ enum v4l2_memory { V4L2_MEMORY_DMABUF = 4, };
-#define V4L2_FLAG_MEMORY_NON_CONSISTENT (1 << 0) - /* see also http://vektor.theorem.ca/graphics/ycbcr/ */ enum v4l2_colorspace { /* @@ -949,10 +947,7 @@ struct v4l2_requestbuffers { __u32 type; /* enum v4l2_buf_type */ __u32 memory; /* enum v4l2_memory */ __u32 capabilities; - union { - __u32 flags; - __u32 reserved[1]; - }; + __u32 reserved[1]; };
/* capabilities for struct v4l2_requestbuffers and v4l2_create_buffers */ @@ -2456,9 +2451,6 @@ struct v4l2_dbg_chip_info { * @memory: enum v4l2_memory; buffer memory type * @format: frame format, for which buffers are requested * @capabilities: capabilities of this buffer type. - * @flags: additional buffer management attributes (ignored unless the - * queue has V4L2_BUF_CAP_SUPPORTS_MMAP_CACHE_HINTS capability - * and configured for MMAP streaming I/O). * @reserved: future extensions */ struct v4l2_create_buffers { @@ -2467,8 +2459,7 @@ struct v4l2_create_buffers { __u32 memory; struct v4l2_format format; __u32 capabilities; - __u32 flags; - __u32 reserved[6]; + __u32 reserved[7]; };
/*