2 files changed, 270 insertions, 59 deletions

diff --git a/drivers/media/video/videobuf2-core.c b/drivers/media/video/videobuf2-core.c
index f04f27d68cec..9005dc9991ab 100644
--- a/drivers/media/video/videobuf2-core.c
+++ b/drivers/media/video/videobuf2-core.c
@@ -38,7 +38,8 @@ module_param(debug, int, 0644);
         (((q)->ops->op) ? ((q)->ops->op(args)) : 0)
 
 #define V4L2_BUFFER_STATE_FLAGS (V4L2_BUF_FLAG_MAPPED | V4L2_BUF_FLAG_QUEUED | \
-                                 V4L2_BUF_FLAG_DONE | V4L2_BUF_FLAG_ERROR)
+                                 V4L2_BUF_FLAG_DONE | V4L2_BUF_FLAG_ERROR | \
+                                 V4L2_BUF_FLAG_PREPARED)
 
 /**
  * __vb2_buf_mem_alloc() - allocate video memory for the given buffer
@@ -109,13 +110,22 @@ static void __vb2_buf_userptr_put(struct vb2_buffer *vb)
  * __setup_offsets() - setup unique offsets ("cookies") for every plane in
  * every buffer on the queue
  */
-static void __setup_offsets(struct vb2_queue *q)
+static void __setup_offsets(struct vb2_queue *q, unsigned int n)
 {
         unsigned int buffer, plane;
         struct vb2_buffer *vb;
-        unsigned long off = 0;
+        unsigned long off;
 
-        for (buffer = 0; buffer < q->num_buffers; ++buffer) {
+        if (q->num_buffers) {
+                struct v4l2_plane *p;
+                vb = q->bufs[q->num_buffers - 1];
+                p = &vb->v4l2_planes[vb->num_planes - 1];
+                off = PAGE_ALIGN(p->m.mem_offset + p->length);
+        } else {
+                off = 0;
+        }
+
+        for (buffer = q->num_buffers; buffer < q->num_buffers + n; ++buffer) {
                 vb = q->bufs[buffer];
                 if (!vb)
                         continue;
@@ -161,7 +171,7 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum v4l2_memory memory,
                 vb->state = VB2_BUF_STATE_DEQUEUED;
                 vb->vb2_queue = q;
                 vb->num_planes = num_planes;
-                vb->v4l2_buf.index = buffer;
+                vb->v4l2_buf.index = q->num_buffers + buffer;
                 vb->v4l2_buf.type = q->type;
                 vb->v4l2_buf.memory = memory;
 
@@ -189,15 +199,13 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum v4l2_memory memory,
                         }
                 }
 
-                q->bufs[buffer] = vb;
+                q->bufs[q->num_buffers + buffer] = vb;
         }
 
-        q->num_buffers = buffer;
-
-        __setup_offsets(q);
+        __setup_offsets(q, buffer);
 
         dprintk(1, "Allocated %d buffers, %d plane(s) each\n",
-                        q->num_buffers, num_planes);
+                        buffer, num_planes);
 
         return buffer;
 }
@@ -205,12 +213,13 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum v4l2_memory memory,
 /**
  * __vb2_free_mem() - release all video buffer memory for a given queue
  */
-static void __vb2_free_mem(struct vb2_queue *q)
+static void __vb2_free_mem(struct vb2_queue *q, unsigned int buffers)
 {
         unsigned int buffer;
         struct vb2_buffer *vb;
 
-        for (buffer = 0; buffer < q->num_buffers; ++buffer) {
+        for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
+             ++buffer) {
                 vb = q->bufs[buffer];
                 if (!vb)
                         continue;
@@ -224,17 +233,18 @@ static void __vb2_free_mem(struct vb2_queue *q)
 }
 
 /**
- * __vb2_queue_free() - free the queue - video memory and related information
- * and return the queue to an uninitialized state. Might be called even if the
- * queue has already been freed.
+ * __vb2_queue_free() - free buffers at the end of the queue - video memory and
+ * related information, if no buffers are left return the queue to an
+ * uninitialized state. Might be called even if the queue has already been freed.
  */
-static void __vb2_queue_free(struct vb2_queue *q)
+static void __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
 {
         unsigned int buffer;
 
         /* Call driver-provided cleanup function for each buffer, if provided */
         if (q->ops->buf_cleanup) {
-                for (buffer = 0; buffer < q->num_buffers; ++buffer) {
+                for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
+                     ++buffer) {
                         if (NULL == q->bufs[buffer])
                                 continue;
                         q->ops->buf_cleanup(q->bufs[buffer]);
@@ -242,23 +252,25 @@ static void __vb2_queue_free(struct vb2_queue *q)
         }
 
         /* Release video buffer memory */
-        __vb2_free_mem(q);
+        __vb2_free_mem(q, buffers);
 
         /* Free videobuf buffers */
-        for (buffer = 0; buffer < q->num_buffers; ++buffer) {
+        for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
+             ++buffer) {
                 kfree(q->bufs[buffer]);
                 q->bufs[buffer] = NULL;
         }
 
-        q->num_buffers = 0;
-        q->memory = 0;
+        q->num_buffers -= buffers;
+        if (!q->num_buffers)
+                q->memory = 0;
 }
 
 /**
  * __verify_planes_array() - verify that the planes array passed in struct
  * v4l2_buffer from userspace can be safely used
  */
-static int __verify_planes_array(struct vb2_buffer *vb, struct v4l2_buffer *b)
+static int __verify_planes_array(struct vb2_buffer *vb, const struct v4l2_buffer *b)
 {
         /* Is memory for copying plane information present? */
         if (NULL == b->m.planes) {
@@ -318,7 +330,7 @@ static bool __buffers_in_use(struct vb2_queue *q)
 static int __fill_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b)
 {
         struct vb2_queue *q = vb->vb2_queue;
-        int ret = 0;
+        int ret;
 
         /* Copy back data such as timestamp, flags, input, etc. */
         memcpy(b, &vb->v4l2_buf, offsetof(struct v4l2_buffer, m));
@@ -365,8 +377,10 @@ static int __fill_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b)
         case VB2_BUF_STATE_DONE:
                 b->flags |= V4L2_BUF_FLAG_DONE;
                 break;
-        case VB2_BUF_STATE_DEQUEUED:
         case VB2_BUF_STATE_PREPARED:
+                b->flags |= V4L2_BUF_FLAG_PREPARED;
+                break;
+        case VB2_BUF_STATE_DEQUEUED:
                 /* nothing */
                 break;
         }
@@ -374,7 +388,7 @@ static int __fill_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b)
         if (__buffer_in_use(q, vb))
                 b->flags |= V4L2_BUF_FLAG_MAPPED;
 
-        return ret;
+        return 0;
 }
 
 /**
@@ -460,7 +474,7 @@ static int __verify_mmap_ops(struct vb2_queue *q)
  */
 int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
 {
-        unsigned int num_buffers, num_planes;
+        unsigned int num_buffers, allocated_buffers, num_planes = 0;
         int ret = 0;
 
         if (q->fileio) {
@@ -508,7 +522,7 @@ int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
                         return -EBUSY;
                 }
 
-                __vb2_queue_free(q);
+                __vb2_queue_free(q, q->num_buffers);
 
                 /*
                  * In case of REQBUFS(0) return immediately without calling
@@ -542,44 +556,168 @@ int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
                 return -ENOMEM;
         }
 
+        allocated_buffers = ret;
+
         /*
          * Check if driver can handle the allocated number of buffers.
          */
-        if (ret < num_buffers) {
-                unsigned int orig_num_buffers;
+        if (allocated_buffers < num_buffers) {
+                num_buffers = allocated_buffers;
 
-                orig_num_buffers = num_buffers = ret;
                 ret = call_qop(q, queue_setup, q, NULL, &num_buffers,
                                &num_planes, q->plane_sizes, q->alloc_ctx);
-                if (ret)
-                        goto free_mem;
 
-                if (orig_num_buffers < num_buffers) {
+                if (!ret && allocated_buffers < num_buffers)
                         ret = -ENOMEM;
-                        goto free_mem;
-                }
 
                 /*
-                 * Ok, driver accepted smaller number of buffers.
+                 * Either the driver has accepted a smaller number of buffers,
+                 * or .queue_setup() returned an error
                  */
-                ret = num_buffers;
+        }
+
+        q->num_buffers = allocated_buffers;
+
+        if (ret < 0) {
+                __vb2_queue_free(q, allocated_buffers);
+                return ret;
         }
 
         /*
          * Return the number of successfully allocated buffers
          * to the userspace.
          */
-        req->count = ret;
+        req->count = allocated_buffers;
 
         return 0;
-
-free_mem:
-        __vb2_queue_free(q);
-        return ret;
 }
 EXPORT_SYMBOL_GPL(vb2_reqbufs);
 
 /**
+ * vb2_create_bufs() - Allocate buffers and any required auxiliary structs
+ * @q:          videobuf2 queue
+ * @create:     creation parameters, passed from userspace to vidioc_create_bufs
+ *              handler in driver
+ *
+ * Should be called from vidioc_create_bufs ioctl handler of a driver.
+ * This function:
+ * 1) verifies parameter sanity
+ * 2) calls the .queue_setup() queue operation
+ * 3) performs any necessary memory allocations
+ *
+ * The return values from this function are intended to be directly returned
+ * from vidioc_create_bufs handler in driver.
+ */
+int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
+{
+        unsigned int num_planes = 0, num_buffers, allocated_buffers;
+        int ret = 0;
+
+        if (q->fileio) {
+                dprintk(1, "%s(): file io in progress\n", __func__);
+                return -EBUSY;
+        }
+
+        if (create->memory != V4L2_MEMORY_MMAP
+                        && create->memory != V4L2_MEMORY_USERPTR) {
+                dprintk(1, "%s(): unsupported memory type\n", __func__);
+                return -EINVAL;
+        }
+
+        if (create->format.type != q->type) {
+                dprintk(1, "%s(): requested type is incorrect\n", __func__);
+                return -EINVAL;
+        }
+
+        /*
+         * Make sure all the required memory ops for given memory type
+         * are available.
+         */
+        if (create->memory == V4L2_MEMORY_MMAP && __verify_mmap_ops(q)) {
+                dprintk(1, "%s(): MMAP for current setup unsupported\n", __func__);
+                return -EINVAL;
+        }
+
+        if (create->memory == V4L2_MEMORY_USERPTR && __verify_userptr_ops(q)) {
+                dprintk(1, "%s(): USERPTR for current setup unsupported\n", __func__);
+                return -EINVAL;
+        }
+
+        if (q->num_buffers == VIDEO_MAX_FRAME) {
+                dprintk(1, "%s(): maximum number of buffers already allocated\n",
+                        __func__);
+                return -ENOBUFS;
+        }
+
+        create->index = q->num_buffers;
+
+        if (!q->num_buffers) {
+                memset(q->plane_sizes, 0, sizeof(q->plane_sizes));
+                memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx));
+                q->memory = create->memory;
+        }
+
+        num_buffers = min(create->count, VIDEO_MAX_FRAME - q->num_buffers);
+
+        /*
+         * Ask the driver, whether the requested number of buffers, planes per
+         * buffer and their sizes are acceptable
+         */
+        ret = call_qop(q, queue_setup, q, &create->format, &num_buffers,
+                       &num_planes, q->plane_sizes, q->alloc_ctx);
+        if (ret)
+                return ret;
+
+        /* Finally, allocate buffers and video memory */
+        ret = __vb2_queue_alloc(q, create->memory, num_buffers,
+                                num_planes);
+        if (ret < 0) {
+                dprintk(1, "Memory allocation failed with error: %d\n", ret);
+                return ret;
+        }
+
+        allocated_buffers = ret;
+
+        /*
+         * Check if driver can handle the so far allocated number of buffers.
+         */
+        if (ret < num_buffers) {
+                num_buffers = ret;
+
+                /*
+                 * q->num_buffers contains the total number of buffers, that the
+                 * queue driver has set up
+                 */
+                ret = call_qop(q, queue_setup, q, &create->format, &num_buffers,
+                               &num_planes, q->plane_sizes, q->alloc_ctx);
+
+                if (!ret && allocated_buffers < num_buffers)
+                        ret = -ENOMEM;
+
+                /*
+                 * Either the driver has accepted a smaller number of buffers,
+                 * or .queue_setup() returned an error
+                 */
+        }
+
+        q->num_buffers += allocated_buffers;
+
+        if (ret < 0) {
+                __vb2_queue_free(q, allocated_buffers);
+                return ret;
+        }
+
+        /*
+         * Return the number of successfully allocated buffers
+         * to the userspace.
+         */
+        create->count = allocated_buffers;
+
+        return 0;
+}
+EXPORT_SYMBOL_GPL(vb2_create_bufs);
+
+/**
  * vb2_plane_vaddr() - Return a kernel virtual address of a given plane
  * @vb:         vb2_buffer to which the plane in question belongs to
  * @plane_no:   plane number for which the address is to be returned
@@ -663,7 +801,7 @@ EXPORT_SYMBOL_GPL(vb2_buffer_done);
  * __fill_vb2_buffer() - fill a vb2_buffer with information provided in
  * a v4l2_buffer by the userspace
  */
-static int __fill_vb2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b,
+static int __fill_vb2_buffer(struct vb2_buffer *vb, const struct v4l2_buffer *b,
                                 struct v4l2_plane *v4l2_planes)
 {
         unsigned int plane;
@@ -727,7 +865,7 @@ static int __fill_vb2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b,
 /**
  * __qbuf_userptr() - handle qbuf of a USERPTR buffer
  */
-static int __qbuf_userptr(struct vb2_buffer *vb, struct v4l2_buffer *b)
+static int __qbuf_userptr(struct vb2_buffer *vb, const struct v4l2_buffer *b)
 {
         struct v4l2_plane planes[VIDEO_MAX_PLANES];
         struct vb2_queue *q = vb->vb2_queue;
@@ -816,7 +954,7 @@ err:
 /**
  * __qbuf_mmap() - handle qbuf of an MMAP buffer
  */
-static int __qbuf_mmap(struct vb2_buffer *vb, struct v4l2_buffer *b)
+static int __qbuf_mmap(struct vb2_buffer *vb, const struct v4l2_buffer *b)
 {
         return __fill_vb2_buffer(vb, b, vb->v4l2_planes);
 }
@@ -833,7 +971,7 @@ static void __enqueue_in_driver(struct vb2_buffer *vb)
         q->ops->buf_queue(vb);
 }
 
-static int __buf_prepare(struct vb2_buffer *vb, struct v4l2_buffer *b)
+static int __buf_prepare(struct vb2_buffer *vb, const struct v4l2_buffer *b)
 {
         struct vb2_queue *q = vb->vb2_queue;
         int ret;
@@ -861,6 +999,68 @@ static int __buf_prepare(struct vb2_buffer *vb, struct v4l2_buffer *b)
 }
 
 /**
+ * vb2_prepare_buf() - Pass ownership of a buffer from userspace to the kernel
+ * @q:          videobuf2 queue
+ * @b:          buffer structure passed from userspace to vidioc_prepare_buf
+ *              handler in driver
+ *
+ * Should be called from vidioc_prepare_buf ioctl handler of a driver.
+ * This function:
+ * 1) verifies the passed buffer,
+ * 2) calls buf_prepare callback in the driver (if provided), in which
+ *    driver-specific buffer initialization can be performed,
+ *
+ * The return values from this function are intended to be directly returned
+ * from vidioc_prepare_buf handler in driver.
+ */
+int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b)
+{
+        struct vb2_buffer *vb;
+        int ret;
+
+        if (q->fileio) {
+                dprintk(1, "%s(): file io in progress\n", __func__);
+                return -EBUSY;
+        }
+
+        if (b->type != q->type) {
+                dprintk(1, "%s(): invalid buffer type\n", __func__);
+                return -EINVAL;
+        }
+
+        if (b->index >= q->num_buffers) {
+                dprintk(1, "%s(): buffer index out of range\n", __func__);
+                return -EINVAL;
+        }
+
+        vb = q->bufs[b->index];
+        if (NULL == vb) {
+                /* Should never happen */
+                dprintk(1, "%s(): buffer is NULL\n", __func__);
+                return -EINVAL;
+        }
+
+        if (b->memory != q->memory) {
+                dprintk(1, "%s(): invalid memory type\n", __func__);
+                return -EINVAL;
+        }
+
+        if (vb->state != VB2_BUF_STATE_DEQUEUED) {
+                dprintk(1, "%s(): invalid buffer state %d\n", __func__, vb->state);
+                return -EINVAL;
+        }
+
+        ret = __buf_prepare(vb, b);
+        if (ret < 0)
+                return ret;
+
+        __fill_v4l2_buffer(vb, b);
+
+        return 0;
+}
+EXPORT_SYMBOL_GPL(vb2_prepare_buf);
+
+/**
  * vb2_qbuf() - Queue a buffer from userspace
  * @q:          videobuf2 queue
  * @b:          buffer structure passed from userspace to vidioc_qbuf handler
@@ -1484,7 +1684,7 @@ void vb2_queue_release(struct vb2_queue *q)
 {
         __vb2_cleanup_fileio(q);
         __vb2_queue_cancel(q);
-        __vb2_queue_free(q);
+        __vb2_queue_free(q, q->num_buffers);
 }
 EXPORT_SYMBOL_GPL(vb2_queue_release);
 
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index 692e35c232a9..55c57d3d3e63 100644
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -169,13 +169,21 @@ struct vb2_buffer {
 /**
  * struct vb2_ops - driver-specific callbacks
  *
- * @queue_setup:        called from a VIDIOC_REQBUFS handler, before
- *                      memory allocation; driver should return the required
- *                      number of buffers in num_buffers, the required number
- *                      of planes per buffer in num_planes; the size of each
- *                      plane should be set in the sizes[] array and optional
- *                      per-plane allocator specific context in alloc_ctxs[]
- *                      array
+ * @queue_setup:        called from VIDIOC_REQBUFS and VIDIOC_CREATE_BUFS
+ *                      handlers before memory allocation, or, if
+ *                      *num_planes != 0, after the allocation to verify a
+ *                      smaller number of buffers. Driver should return
+ *                      the required number of buffers in *num_buffers, the
+ *                      required number of planes per buffer in *num_planes; the
+ *                      size of each plane should be set in the sizes[] array
+ *                      and optional per-plane allocator specific context in the
+ *                      alloc_ctxs[] array. When called from VIDIOC_REQBUFS,
+ *                      fmt == NULL, the driver has to use the currently
+ *                      configured format and *num_buffers is the total number
+ *                      of buffers, that are being allocated. When called from
+ *                      VIDIOC_CREATE_BUFS, fmt != NULL and it describes the
+ *                      target frame format. In this case *num_buffers are being
+ *                      allocated additionally to q->num_buffers.
  * @wait_prepare:       release any locks taken while calling vb2 functions;
  *                      it is called before an ioctl needs to wait for a new
  *                      buffer to arrive; required to avoid a deadlock in
@@ -188,11 +196,11 @@ struct vb2_buffer {
  *                      perform additional buffer-related initialization;
  *                      initialization failure (return != 0) will prevent
  *                      queue setup from completing successfully; optional
- * @buf_prepare:        called every time the buffer is queued from userspace;
- *                      drivers may perform any initialization required before
- *                      each hardware operation in this callback;
- *                      if an error is returned, the buffer will not be queued
- *                      in driver; optional
+ * @buf_prepare:        called every time the buffer is queued from userspace
+ *                      and from the VIDIOC_PREPARE_BUF ioctl; drivers may
+ *                      perform any initialization required before each hardware
+ *                      operation in this callback; if an error is returned, the
+ *                      buffer will not be queued in driver; optional
  * @buf_finish:         called before every dequeue of the buffer back to
  *                      userspace; drivers may perform any operations required
  *                      before userspace accesses the buffer; optional
@@ -300,6 +308,9 @@ int vb2_wait_for_all_buffers(struct vb2_queue *q);
 int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b);
 int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req);
 
+int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create);
+int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b);
+
 int vb2_queue_init(struct vb2_queue *q);
 
 void vb2_queue_release(struct vb2_queue *q);