[media] media: i.MX27 camera: more efficient discard buffer handling

Some elements of 'mx2_buffer' are grouped together in another
auxiliary structure. This way we don't need to have unused
'vb2_buffer' structures for both discard buffers.

Signed-off-by: Javier Martin <javier.martin@vista-silicon.com>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 45 insertions, 32 deletions

diff --git a/drivers/media/video/mx2_camera.c b/drivers/media/video/mx2_camera.c
index 1f7e36c2116e..06675125f838 100644
--- a/drivers/media/video/mx2_camera.c
+++ b/drivers/media/video/mx2_camera.c
@@ -228,15 +228,18 @@ enum mx2_buffer_state {
         MX2_STATE_DONE,
 };
 
+struct mx2_buf_internal {
+        struct list_head        queue;
+        int                     bufnum;
+        bool                    discard;
+};
+
 /* buffer for one video frame */
 struct mx2_buffer {
         /* common v4l buffer stuff -- must be first */
         struct vb2_buffer               vb;
-        struct list_head                queue;
         enum mx2_buffer_state           state;
-
-        int                             bufnum;
-        bool                            discard;
+        struct mx2_buf_internal         internal;
 };
 
 struct mx2_camera_dev {
@@ -266,7 +269,7 @@ struct mx2_camera_dev {
 
         u32                     csicr1;
 
-        struct mx2_buffer       buf_discard[2];
+        struct mx2_buf_internal buf_discard[2];
         void                    *discard_buffer;
         dma_addr_t              discard_buffer_dma;
         size_t                  discard_size;
@@ -275,6 +278,11 @@ struct mx2_camera_dev {
         struct vb2_alloc_ctx    *alloc_ctx;
 };
 
+static struct mx2_buffer *mx2_ibuf_to_buf(struct mx2_buf_internal *int_buf)
+{
+        return container_of(int_buf, struct mx2_buffer, internal);
+}
+
 static struct mx2_fmt_cfg mx27_emma_prp_table[] = {
         /*
          * This is a generic configuration which is valid for most
@@ -450,9 +458,9 @@ static void mx25_camera_frame_done(struct mx2_camera_dev *pcdev, int fb,
                 writel(0, pcdev->base_csi + fb_reg);
         } else {
                 buf = list_first_entry(&pcdev->capture, struct mx2_buffer,
-                                queue);
+                                internal.queue);
                 vb = &buf->vb;
-                list_del(&buf->queue);
+                list_del(&buf->internal.queue);
                 buf->state = MX2_STATE_ACTIVE;
                 writel(vb2_dma_contig_plane_dma_addr(vb, 0),
                        pcdev->base_csi + fb_reg);
@@ -569,7 +577,7 @@ static void mx2_videobuf_queue(struct vb2_buffer *vb)
         spin_lock_irqsave(&pcdev->lock, flags);
 
         buf->state = MX2_STATE_QUEUED;
-        list_add_tail(&buf->queue, &pcdev->capture);
+        list_add_tail(&buf->internal.queue, &pcdev->capture);
 
         if (cpu_is_mx25()) {
                 u32 csicr3, dma_inten = 0;
@@ -587,7 +595,7 @@ static void mx2_videobuf_queue(struct vb2_buffer *vb)
                 }
 
                 if (dma_inten) {
-                        list_del(&buf->queue);
+                        list_del(&buf->internal.queue);
                         buf->state = MX2_STATE_ACTIVE;
 
                         csicr3 = readl(pcdev->base_csi + CSICR3);
@@ -710,23 +718,23 @@ static int mx2_start_streaming(struct vb2_queue *q, unsigned int count)
                 spin_lock_irqsave(&pcdev->lock, flags);
 
                 buf = list_first_entry(&pcdev->capture, struct mx2_buffer,
-                                       queue);
-                buf->bufnum = 0;
+                                       internal.queue);
+                buf->internal.bufnum = 0;
                 vb = &buf->vb;
                 buf->state = MX2_STATE_ACTIVE;
 
                 phys = vb2_dma_contig_plane_dma_addr(vb, 0);
-                mx27_update_emma_buf(pcdev, phys, buf->bufnum);
+                mx27_update_emma_buf(pcdev, phys, buf->internal.bufnum);
                 list_move_tail(pcdev->capture.next, &pcdev->active_bufs);
 
                 buf = list_first_entry(&pcdev->capture, struct mx2_buffer,
-                                       queue);
-                buf->bufnum = 1;
+                                       internal.queue);
+                buf->internal.bufnum = 1;
                 vb = &buf->vb;
                 buf->state = MX2_STATE_ACTIVE;
 
                 phys = vb2_dma_contig_plane_dma_addr(vb, 0);
-                mx27_update_emma_buf(pcdev, phys, buf->bufnum);
+                mx27_update_emma_buf(pcdev, phys, buf->internal.bufnum);
                 list_move_tail(pcdev->capture.next, &pcdev->active_bufs);
 
                 bytesperline = soc_mbus_bytes_per_line(icd->user_width,
@@ -1203,21 +1211,25 @@ static void mx27_camera_frame_done_emma(struct mx2_camera_dev *pcdev,
 #ifdef DEBUG
         struct mx2_fmt_cfg *prp = pcdev->emma_prp;
 #endif
+        struct mx2_buf_internal *ibuf;
         struct mx2_buffer *buf;
         struct vb2_buffer *vb;
         unsigned long phys;
 
-        buf = list_first_entry(&pcdev->active_bufs, struct mx2_buffer, queue);
+        ibuf = list_first_entry(&pcdev->active_bufs, struct mx2_buf_internal,
+                               queue);
 
-        BUG_ON(buf->bufnum != bufnum);
+        BUG_ON(ibuf->bufnum != bufnum);
 
-        if (buf->discard) {
+        if (ibuf->discard) {
                 /*
                  * Discard buffer must not be returned to user space.
                  * Just return it to the discard queue.
                  */
                 list_move_tail(pcdev->active_bufs.next, &pcdev->discard);
         } else {
+                buf = mx2_ibuf_to_buf(ibuf);
+
                 vb = &buf->vb;
 #ifdef DEBUG
                 phys = vb2_dma_contig_plane_dma_addr(vb, 0);
@@ -1241,7 +1253,7 @@ static void mx27_camera_frame_done_emma(struct mx2_camera_dev *pcdev,
                                 vb2_plane_vaddr(vb, 0),
                                 vb2_get_plane_payload(vb, 0));
 
-                list_del_init(&buf->queue);
+                list_del_init(&buf->internal.queue);
                 do_gettimeofday(&vb->v4l2_buf.timestamp);
                 vb->v4l2_buf.sequence = pcdev->frame_count;
                 if (err)
@@ -1259,18 +1271,19 @@ static void mx27_camera_frame_done_emma(struct mx2_camera_dev *pcdev,
                         return;
                 }
 
-                buf = list_first_entry(&pcdev->discard, struct mx2_buffer,
-                                       queue);
-                buf->bufnum = bufnum;
+                ibuf = list_first_entry(&pcdev->discard,
+                                        struct mx2_buf_internal, queue);
+                ibuf->bufnum = bufnum;
 
                 list_move_tail(pcdev->discard.next, &pcdev->active_bufs);
                 mx27_update_emma_buf(pcdev, pcdev->discard_buffer_dma, bufnum);
                 return;
         }
 
-        buf = list_first_entry(&pcdev->capture, struct mx2_buffer, queue);
+        buf = list_first_entry(&pcdev->capture, struct mx2_buffer,
+                               internal.queue);
 
-        buf->bufnum = bufnum;
+        buf->internal.bufnum = bufnum;
 
         list_move_tail(pcdev->capture.next, &pcdev->active_bufs);
 
@@ -1285,7 +1298,7 @@ static irqreturn_t mx27_camera_emma_irq(int irq_emma, void *data)
 {
         struct mx2_camera_dev *pcdev = data;
         unsigned int status = readl(pcdev->base_emma + PRP_INTRSTATUS);
-        struct mx2_buffer *buf;
+        struct mx2_buf_internal *ibuf;
 
         spin_lock(&pcdev->lock);
 
@@ -1305,10 +1318,10 @@ static irqreturn_t mx27_camera_emma_irq(int irq_emma, void *data)
                        pcdev->base_emma + PRP_CNTL);
                 writel(cntl, pcdev->base_emma + PRP_CNTL);
 
-                buf = list_first_entry(&pcdev->active_bufs,
-                        struct mx2_buffer, queue);
+                ibuf = list_first_entry(&pcdev->active_bufs,
+                                        struct mx2_buf_internal, queue);
                 mx27_camera_frame_done_emma(pcdev,
-                                        buf->bufnum, true);
+                                        ibuf->bufnum, true);
 
                 status &= ~(1 << 7);
         } else if (((status & (3 << 5)) == (3 << 5)) ||
@@ -1317,10 +1330,10 @@ static irqreturn_t mx27_camera_emma_irq(int irq_emma, void *data)
                  * Both buffers have triggered, process the one we're expecting
                  * to first
                  */
-                buf = list_first_entry(&pcdev->active_bufs, struct mx2_buffer,
-                                       queue);
-                mx27_camera_frame_done_emma(pcdev, buf->bufnum, false);
-                status &= ~(1 << (6 - buf->bufnum)); /* mark processed */
+                ibuf = list_first_entry(&pcdev->active_bufs,
+                                        struct mx2_buf_internal, queue);
+                mx27_camera_frame_done_emma(pcdev, ibuf->bufnum, false);
+                status &= ~(1 << (6 - ibuf->bufnum)); /* mark processed */
         } else if ((status & (1 << 6)) || (status & (1 << 4))) {
                 mx27_camera_frame_done_emma(pcdev, 0, false);
         } else if ((status & (1 << 5)) || (status & (1 << 3))) {