1 files changed, 110 insertions, 23 deletions

diff --git a/drivers/media/video/uvc/uvc_queue.c b/drivers/media/video/uvc/uvc_queue.c
index ed6d5449741c..f14581bd707f 100644
--- a/drivers/media/video/uvc/uvc_queue.c
+++ b/drivers/media/video/uvc/uvc_queue.c
@@ -90,6 +90,39 @@ void uvc_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type,
 }
 
 /*
+ * Free the video buffers.
+ *
+ * This function must be called with the queue lock held.
+ */
+static int __uvc_free_buffers(struct uvc_video_queue *queue)
+{
+        unsigned int i;
+
+        for (i = 0; i < queue->count; ++i) {
+                if (queue->buffer[i].vma_use_count != 0)
+                        return -EBUSY;
+        }
+
+        if (queue->count) {
+                vfree(queue->mem);
+                queue->count = 0;
+        }
+
+        return 0;
+}
+
+int uvc_free_buffers(struct uvc_video_queue *queue)
+{
+        int ret;
+
+        mutex_lock(&queue->mutex);
+        ret = __uvc_free_buffers(queue);
+        mutex_unlock(&queue->mutex);
+
+        return ret;
+}
+
+/*
  * Allocate the video buffers.
  *
  * Pages are reserved to make sure they will not be swapped, as they will be
@@ -110,7 +143,7 @@ int uvc_alloc_buffers(struct uvc_video_queue *queue, unsigned int nbuffers,
 
         mutex_lock(&queue->mutex);
 
-        if ((ret = uvc_free_buffers(queue)) < 0)
+        if ((ret = __uvc_free_buffers(queue)) < 0)
                 goto done;
 
         /* Bail out if no buffers should be allocated. */
@@ -152,28 +185,6 @@ done:
 }
 
 /*
- * Free the video buffers.
- *
- * This function must be called with the queue lock held.
- */
-int uvc_free_buffers(struct uvc_video_queue *queue)
-{
-        unsigned int i;
-
-        for (i = 0; i < queue->count; ++i) {
-                if (queue->buffer[i].vma_use_count != 0)
-                        return -EBUSY;
-        }
-
-        if (queue->count) {
-                vfree(queue->mem);
-                queue->count = 0;
-        }
-
-        return 0;
-}
-
-/*
  * Check if buffers have been allocated.
  */
 int uvc_queue_allocated(struct uvc_video_queue *queue)
@@ -369,6 +380,82 @@ done:
 }
 
 /*
+ * VMA operations.
+ */
+static void uvc_vm_open(struct vm_area_struct *vma)
+{
+        struct uvc_buffer *buffer = vma->vm_private_data;
+        buffer->vma_use_count++;
+}
+
+static void uvc_vm_close(struct vm_area_struct *vma)
+{
+        struct uvc_buffer *buffer = vma->vm_private_data;
+        buffer->vma_use_count--;
+}
+
+static const struct vm_operations_struct uvc_vm_ops = {
+        .open           = uvc_vm_open,
+        .close          = uvc_vm_close,
+};
+
+/*
+ * Memory-map a video buffer.
+ *
+ * This function implements video buffers memory mapping and is intended to be
+ * used by the device mmap handler.
+ */
+int uvc_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma)
+{
+        struct uvc_buffer *uninitialized_var(buffer);
+        struct page *page;
+        unsigned long addr, start, size;
+        unsigned int i;
+        int ret = 0;
+
+        start = vma->vm_start;
+        size = vma->vm_end - vma->vm_start;
+
+        mutex_lock(&queue->mutex);
+
+        for (i = 0; i < queue->count; ++i) {
+                buffer = &queue->buffer[i];
+                if ((buffer->buf.m.offset >> PAGE_SHIFT) == vma->vm_pgoff)
+                        break;
+        }
+
+        if (i == queue->count || size != queue->buf_size) {
+                ret = -EINVAL;
+                goto done;
+        }
+
+        /*
+         * VM_IO marks the area as being an mmaped region for I/O to a
+         * device. It also prevents the region from being core dumped.
+         */
+        vma->vm_flags |= VM_IO;
+
+        addr = (unsigned long)queue->mem + buffer->buf.m.offset;
+        while (size > 0) {
+                page = vmalloc_to_page((void *)addr);
+                if ((ret = vm_insert_page(vma, start, page)) < 0)
+                        goto done;
+
+                start += PAGE_SIZE;
+                addr += PAGE_SIZE;
+                size -= PAGE_SIZE;
+        }
+
+        vma->vm_ops = &uvc_vm_ops;
+        vma->vm_private_data = buffer;
+        uvc_vm_open(vma);
+
+done:
+        mutex_unlock(&queue->mutex);
+        return ret;
+}
+
+/*
  * Poll the video queue.
  *
  * This function implements video queue polling and is intended to be used by