From patchwork Mon Dec 6 10:52:43 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marek Szyprowski X-Patchwork-Id: 377522 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter1.kernel.org (8.14.4/8.14.3) with ESMTP id oB6Ara6O016727 for ; Mon, 6 Dec 2010 10:53:41 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752296Ab0LFKxK (ORCPT ); Mon, 6 Dec 2010 05:53:10 -0500 Received: from mailout3.w1.samsung.com ([210.118.77.13]:15679 "EHLO mailout3.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752098Ab0LFKw5 (ORCPT ); Mon, 6 Dec 2010 05:52:57 -0500 MIME-version: 1.0 Content-transfer-encoding: 7BIT Content-type: TEXT/PLAIN Received: from spt2.w1.samsung.com ([210.118.77.13]) by mailout3.w1.samsung.com (Sun Java(tm) System Messaging Server 6.3-8.04 (built Jul 29 2009; 32bit)) with ESMTP id <0LD0005CF6848840@mailout3.w1.samsung.com> for linux-media@vger.kernel.org; Mon, 06 Dec 2010 10:52:53 +0000 (GMT) Received: from linux.samsung.com ([106.116.38.10]) by spt2.w1.samsung.com (iPlanet Messaging Server 5.2 Patch 2 (built Jul 14 2004)) with ESMTPA id <0LD000498684TT@spt2.w1.samsung.com> for linux-media@vger.kernel.org; Mon, 06 Dec 2010 10:52:52 +0000 (GMT) Received: from mcdsrvbld02.digital.local (unknown [106.116.37.23]) by linux.samsung.com (Postfix) with ESMTP id D200027004F; Mon, 06 Dec 2010 11:52:21 +0100 (CET) Date: Mon, 06 Dec 2010 11:52:43 +0100 From: Marek Szyprowski Subject: [PATCH 6/8] v4l: videobuf2: add read() and write() emulator In-reply-to: <1291632765-11207-1-git-send-email-m.szyprowski@samsung.com> To: linux-media@vger.kernel.org Cc: m.szyprowski@samsung.com, pawel@osciak.com, kyungmin.park@samsung.com, andrzej.p@samsung.com Message-id: <1291632765-11207-7-git-send-email-m.szyprowski@samsung.com> X-Mailer: git-send-email 1.7.1 References: <1291632765-11207-1-git-send-email-m.szyprowski@samsung.com> Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.3 (demeter1.kernel.org [140.211.167.41]); Mon, 06 Dec 2010 10:53:41 +0000 (UTC) diff --git a/drivers/media/video/videobuf2-core.c b/drivers/media/video/videobuf2-core.c index e149acd..5561c32 100644 --- a/drivers/media/video/videobuf2-core.c +++ b/drivers/media/video/videobuf2-core.c @@ -453,6 +453,11 @@ int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req) unsigned long plane_sizes[VIDEO_MAX_PLANES]; int ret = 0; + if (q->fileio) { + dprintk(1, "reqbufs: file io in progress\n"); + return -EBUSY; + } + if (req->memory != V4L2_MEMORY_MMAP && req->memory != V4L2_MEMORY_USERPTR) { dprintk(1, "reqbufs: unsupported memory type\n"); @@ -819,6 +824,11 @@ int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b) struct vb2_buffer *vb; int ret = 0; + if (q->fileio) { + dprintk(1, "qbuf: file io in progress\n"); + return -EBUSY; + } + if (b->type != q->type) { dprintk(1, "qbuf: invalid buffer type\n"); return -EINVAL; @@ -1021,6 +1031,11 @@ int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking) struct vb2_buffer *vb = NULL; int ret; + if (q->fileio) { + dprintk(1, "dqbuf: file io in progress\n"); + return -EBUSY; + } + if (b->type != q->type) { dprintk(1, "dqbuf: invalid buffer type\n"); return -EINVAL; @@ -1080,6 +1095,11 @@ int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type) { struct vb2_buffer *vb; + if (q->fileio) { + dprintk(1, "streamon: file io in progress\n"); + return -EBUSY; + } + if (type != q->type) { dprintk(1, "streamon: invalid stream type\n"); return -EINVAL; @@ -1173,6 +1193,11 @@ static void __vb2_queue_cancel(struct vb2_queue *q) */ int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type) { + if (q->fileio) { + dprintk(1, "streamoff: file io in progress\n"); + return -EBUSY; + } + if (type != q->type) { dprintk(1, "streamoff: invalid stream type\n"); return -EINVAL; @@ -1296,6 +1321,8 @@ int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma) } EXPORT_SYMBOL_GPL(vb2_mmap); +static int __vb2_init_fileio(struct vb2_queue *q, int read); +static int __vb2_cleanup_fileio(struct vb2_queue *q); /** * vb2_poll() - implements poll userspace operation @@ -1316,9 +1343,30 @@ EXPORT_SYMBOL_GPL(vb2_mmap); unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait) { unsigned long flags; + unsigned int ret; struct vb2_buffer *vb = NULL; /* + * Start file io emulator if streaming api has not been used yet. + */ + if (q->num_buffers == 0 && q->fileio == NULL) { + if (!V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_READ)) { + ret = __vb2_init_fileio(q, 1); + if (ret) + return ret; + } + if (V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_WRITE)) { + ret = __vb2_init_fileio(q, 0); + if (ret) + return ret; + /* + * Write to OUTPUT queue can be done immediately. + */ + return POLLOUT | POLLWRNORM; + } + } + + /* * There is nothing to wait for if no buffers have already been queued. */ if (list_empty(&q->queued_list)) @@ -1390,11 +1438,362 @@ EXPORT_SYMBOL_GPL(vb2_queue_init); */ void vb2_queue_release(struct vb2_queue *q) { + __vb2_cleanup_fileio(q); __vb2_queue_cancel(q); __vb2_queue_free(q); } EXPORT_SYMBOL_GPL(vb2_queue_release); +/** + * struct vb2_fileio_buf - buffer context used by file io emulator + * + * vb2 provides a compatibility layer and emulator of file io (read and + * write) calls on top of streaming API. This structure is used for + * tracking context related to the buffers. + */ +struct vb2_fileio_buf { + void *vaddr; + unsigned int size; + unsigned int pos; + unsigned int queued:1; +}; + +/** + * struct vb2_fileio_data - queue context used by file io emulator + * + * vb2 provides a compatibility layer and emulator of file io (read and + * write) calls on top of streaming API. For proper operation it required + * this structure to save the driver state between each call of the read + * or write function. + */ +struct vb2_fileio_data { + struct v4l2_requestbuffers req; + struct v4l2_buffer b; + struct vb2_fileio_buf bufs[VIDEO_MAX_FRAME]; + unsigned int index; + unsigned int q_count; + unsigned int dq_count; + unsigned int flags; +}; + +/** + * __vb2_init_fileio() - initialize file io emulator + * @q: videobuf2 queue + * @read: mode selector (1 means read, 0 means write) + */ +static int __vb2_init_fileio(struct vb2_queue *q, int read) +{ + struct vb2_fileio_data *fileio; + int i, ret; + unsigned int count = 0; + + /* + * Sanity check + */ + if ((read && !(q->io_modes & VB2_READ)) || + (!read && !(q->io_modes & VB2_WRITE))) + BUG(); + + /* + * Check if device supports mapping buffers to kernel virtual space. + */ + if (!q->mem_ops->vaddr) + return -EBUSY; + + /* + * Check if streaming api has not been already activated. + */ + if (q->streaming || q->num_buffers > 0) + return -EBUSY; + + /* + * Start with count 1, driver can increase it in queue_setup() + */ + count = 1; + + dprintk(3, "setting up file io: mode %s, count %d, flags %08x\n", + (read) ? "read" : "write", count, q->io_flags); + + fileio = kzalloc(sizeof(struct vb2_fileio_data), GFP_KERNEL); + if (fileio == NULL) + return -ENOMEM; + + fileio->flags = q->io_flags; + + /* + * Request buffers and use MMAP type to force driver + * to allocate buffers by itself. + */ + fileio->req.count = count; + fileio->req.memory = V4L2_MEMORY_MMAP; + fileio->req.type = q->type; + ret = vb2_reqbufs(q, &fileio->req); + if (ret) + goto err_kfree; + + /* + * Check if plane_count is correct + * (multiplane buffers are not supported). + */ + if (q->bufs[0]->num_planes != 1) { + fileio->req.count = 0; + ret = -EBUSY; + goto err_reqbufs; + } + + /* + * Get kernel address of each buffer. + */ + for (i = 0; i < q->num_buffers; i++) { + fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0); + if (fileio->bufs[i].vaddr == NULL) + goto err_reqbufs; + fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0); + } + + /* + * Read mode requires pre queuing of all buffers. + */ + if (read) { + /* + * Queue all buffers. + */ + for (i = 0; i < q->num_buffers; i++) { + struct v4l2_buffer *b = &fileio->b; + memset(b, 0, sizeof(*b)); + b->type = q->type; + b->memory = q->memory; + b->index = i; + ret = vb2_qbuf(q, b); + if (ret) + goto err_reqbufs; + fileio->bufs[i].queued = 1; + } + + /* + * Start streaming. + */ + ret = vb2_streamon(q, q->type); + if (ret) + goto err_reqbufs; + } + + q->fileio = fileio; + + return ret; + +err_reqbufs: + vb2_reqbufs(q, &fileio->req); + +err_kfree: + kfree(fileio); + return ret; +} + +/** + * __vb2_cleanup_fileio() - free resourced used by file io emulator + * @q: videobuf2 queue + */ +static int __vb2_cleanup_fileio(struct vb2_queue *q) +{ + struct vb2_fileio_data *fileio = q->fileio; + + if (fileio) { + /* + * Hack fileio context to enable direct calls to vb2 ioctl + * interface. + */ + q->fileio = NULL; + + vb2_streamoff(q, q->type); + fileio->req.count = 0; + vb2_reqbufs(q, &fileio->req); + kfree(fileio); + dprintk(3, "file io emulator closed\n"); + } + return 0; +} + +/** + * __vb2_perform_fileio() - perform a single file io (read or write) operation + * @q: videobuf2 queue + * @data: pointed to target userspace buffer + * @count: number of bytes to read or write + * @ppos: file handle position tracking pointer + * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking) + * @read: access mode selector (1 means read, 0 means write) + */ +static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_t count, + loff_t *ppos, int nonblock, int read) +{ + struct vb2_fileio_data *fileio; + struct vb2_fileio_buf *buf; + int ret, index; + + dprintk(3, "file io: mode %s, offset %ld, count %d, %sblocking\n", + read ? "read" : "write", (long)*ppos, count, + nonblock ? "non" : ""); + + if (!data) + return -EINVAL; + + /* + * Initialize emulator on first call. + */ + if (!q->fileio) { + ret = __vb2_init_fileio(q, read); + dprintk(3, "file io: vb2_init_fileio result: %d\n", ret); + if (ret) + return ret; + } + fileio = q->fileio; + + /* + * Hack fileio context to enable direct calls to vb2 ioctl interface. + * The pointer will be restored before returning from this function. + */ + q->fileio = NULL; + + index = fileio->index; + buf = &fileio->bufs[index]; + + /* + * Check if we need to dequeue the buffer. + */ + if (buf->queued) { + struct vb2_buffer *vb; + + /* + * Call vb2_dqbuf to get buffer back. + */ + memset(&fileio->b, 0, sizeof(fileio->b)); + fileio->b.type = q->type; + fileio->b.memory = q->memory; + fileio->b.index = index; + ret = vb2_dqbuf(q, &fileio->b, nonblock); + dprintk(5, "file io: vb2_dqbuf result: %d\n", ret); + if (ret) + goto end; + fileio->dq_count += 1; + + /* + * Get number of bytes filled by the driver + */ + vb = q->bufs[index]; + buf->size = vb2_get_plane_payload(vb, 0); + buf->queued = 0; + } + + /* + * Limit count on last few bytes of the buffer. + */ + if (buf->pos + count > buf->size) { + count = buf->size - buf->pos; + dprintk(5, "reducing read count: %d\n", count); + } + + /* + * Transfer data to userspace. + */ + dprintk(3, "file io: copying %d bytes - buffer %d, offset %d\n", + count, index, buf->pos); + if (read) + ret = copy_to_user(data, buf->vaddr + buf->pos, count); + else + ret = copy_from_user(buf->vaddr + buf->pos, data, count); + if (ret) { + dprintk(3, "file io: error copying data\n"); + ret = -EFAULT; + goto end; + } + + /* + * Update counters. + */ + buf->pos += count; + *ppos += count; + + /* + * Queue next buffer if required. + */ + if (buf->pos == buf->size || + (!read && (fileio->flags & VB2_FILEIO_WRITE_IMMEDIATE))) { + /* + * Check if this is the last buffer to read. + */ + if (read && (fileio->flags & VB2_FILEIO_READ_ONCE) && + fileio->dq_count == 1) { + dprintk(3, "file io: read limit reached\n"); + /* + * Restore fileio pointer and release the context. + */ + q->fileio = fileio; + return __vb2_cleanup_fileio(q); + } + + /* + * Call vb2_qbuf and give buffer to the driver. + */ + memset(&fileio->b, 0, sizeof(fileio->b)); + fileio->b.type = q->type; + fileio->b.memory = q->memory; + fileio->b.index = index; + fileio->b.bytesused = buf->pos; + ret = vb2_qbuf(q, &fileio->b); + dprintk(5, "file io: vb2_dbuf result: %d\n", ret); + if (ret) + goto end; + + /* + * Buffer has been queued, update the status + */ + buf->pos = 0; + buf->queued = 1; + buf->size = q->bufs[0]->v4l2_planes[0].length; + fileio->q_count += 1; + + /* + * Switch to the next buffer + */ + fileio->index = (index + 1) % q->num_buffers; + + /* + * Start streaming if required. + */ + if (!read && !q->streaming) { + ret = vb2_streamon(q, q->type); + if (ret) + goto end; + } + } + + /* + * Return proper number of bytes processed. + */ + if (ret == 0) + ret = count; +end: + /* + * Restore the fileio context and block vb2 ioctl interface. + */ + q->fileio = fileio; + return ret; +} + +size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count, + loff_t *ppos, int nonblocking) +{ + return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 1); +} +EXPORT_SYMBOL_GPL(vb2_read); + +size_t vb2_write(struct vb2_queue *q, char __user *data, size_t count, + loff_t *ppos, int nonblocking) +{ + return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 0); +} +EXPORT_SYMBOL_GPL(vb2_write); + MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2"); MODULE_AUTHOR("Pawel Osciak, Marek Szyprowski"); MODULE_LICENSE("GPL"); diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h index 61814fc..8879d0f 100644 --- a/include/media/videobuf2-core.h +++ b/include/media/videobuf2-core.h @@ -18,6 +18,7 @@ #include struct vb2_alloc_ctx; +struct vb2_fileio_data; /** * struct vb2_mem_ops - memory handling/memory allocator operations @@ -54,6 +55,7 @@ struct vb2_alloc_ctx; * * Required ops for USERPTR types: get_userptr, put_userptr. * Required ops for MMAP types: alloc, put, num_users, mmap. + * Required ops for read/write access types: alloc, put, num_users, vaddr */ struct vb2_mem_ops { void *(*alloc)(void *alloc_ctx, unsigned long size); @@ -246,6 +248,7 @@ struct vb2_ops { * @done_wq: waitqueue for processes waiting for buffers ready to be dequeued * @alloc_ctx: memory type/allocator-specific contexts for each plane * @streaming: current streaming state + * @fileio: file io emulator internal data, used only if emulator is active */ struct vb2_queue { enum v4l2_buf_type type; @@ -272,6 +275,8 @@ struct vb2_queue { void *alloc_ctx[VIDEO_MAX_PLANES]; unsigned int streaming:1; + + struct vb2_fileio_data *fileio; }; void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no); @@ -295,6 +300,10 @@ int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type); int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma); unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait); +size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count, + loff_t *ppos, int nonblock); +size_t vb2_write(struct vb2_queue *q, char __user *data, size_t count, + loff_t *ppos, int nonblock); /** * vb2_is_streaming() - return streaming status of the queue