media: vsp1: Use reference counting for bodies

Extend the display list body with a reference count, allowing bodies to
be kept as long as a reference is maintained. This provides the ability
to keep a cached copy of bodies which will not change, so that they can
be re-applied to multiple display lists.

Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

diff --git a/drivers/media/platform/vsp1/vsp1_clu.c b/drivers/media/platform/vsp1/vsp1_clu.c
index 8efa12f5e53f8dbf265869ef03c04d258fc217b6..ea83f1b7d1256c4eb05e7e3d802c5a416b20139d 100644 (file)
--- a/drivers/media/platform/vsp1/vsp1_clu.c
+++ b/drivers/media/platform/vsp1/vsp1_clu.c
@@ -212,8 +212,13 @@ static void clu_configure(struct vsp1_entity *entity,
                clu->clu = NULL;
                spin_unlock_irqrestore(&clu->lock, flags);
 
-               if (dlb)
+               if (dlb) {
                        vsp1_dl_list_add_body(dl, dlb);
+
+                       /* Release our local reference. */
+                       vsp1_dl_body_put(dlb);
+               }
+
                break;
        }
 }

diff --git a/drivers/media/platform/vsp1/vsp1_dl.c b/drivers/media/platform/vsp1/vsp1_dl.c
index 617c46a03dec5b7d9f4a74075f9a8a8e66b74eab..1407c90c68809ef625da60b9463590545cc163af 100644 (file)
--- a/drivers/media/platform/vsp1/vsp1_dl.c
+++ b/drivers/media/platform/vsp1/vsp1_dl.c
@@ -10,6 +10,7 @@
 #include <linux/device.h>
 #include <linux/dma-mapping.h>
 #include <linux/gfp.h>
+#include <linux/refcount.h>
 #include <linux/slab.h>
 #include <linux/workqueue.h>
 
@@ -54,6 +55,8 @@ struct vsp1_dl_body {
        struct list_head list;
        struct list_head free;
 
+       refcount_t refcnt;
+
        struct vsp1_dl_body_pool *pool;
        struct vsp1_device *vsp1;
 
@@ -258,6 +261,7 @@ struct vsp1_dl_body *vsp1_dl_body_get(struct vsp1_dl_body_pool *pool)
        if (!list_empty(&pool->free)) {
                dlb = list_first_entry(&pool->free, struct vsp1_dl_body, free);
                list_del(&dlb->free);
+               refcount_set(&dlb->refcnt, 1);
        }
 
        spin_unlock_irqrestore(&pool->lock, flags);
@@ -278,6 +282,9 @@ void vsp1_dl_body_put(struct vsp1_dl_body *dlb)
        if (!dlb)
                return;
 
+       if (!refcount_dec_and_test(&dlb->refcnt))
+               return;
+
        dlb->num_entries = 0;
 
        spin_lock_irqsave(&dlb->pool->lock, flags);
@@ -463,8 +470,11 @@ void vsp1_dl_list_write(struct vsp1_dl_list *dl, u32 reg, u32 data)
  * which bodies are added.
  *
  * Adding a body to a display list passes ownership of the body to the list. The
- * caller must not touch the body after this call, and must not release it
- * explicitly with vsp1_dl_body_put().
+ * caller retains its reference to the fragment when adding it to the display
+ * list, but is not allowed to add new entries to the body.
+ *
+ * The reference must be explicitly released by a call to vsp1_dl_body_put()
+ * when the body isn't needed anymore.
  *
  * Additional bodies are only usable for display lists in header mode.
  * Attempting to add a body to a header-less display list will return an error.
@@ -475,6 +485,8 @@ int vsp1_dl_list_add_body(struct vsp1_dl_list *dl, struct vsp1_dl_body *dlb)
        if (dl->dlm->mode != VSP1_DL_MODE_HEADER)
                return -EINVAL;
 
+       refcount_inc(&dlb->refcnt);
+
        list_add_tail(&dlb->list, &dl->bodies);
 
        return 0;

diff --git a/drivers/media/platform/vsp1/vsp1_lut.c b/drivers/media/platform/vsp1/vsp1_lut.c
index 6b358617ce153d36e0a6d3edeef683b516bdd88c..b3ea90172439da3ee9398ae5d50ee2b213d95d96 100644 (file)
--- a/drivers/media/platform/vsp1/vsp1_lut.c
+++ b/drivers/media/platform/vsp1/vsp1_lut.c
@@ -168,8 +168,13 @@ static void lut_configure(struct vsp1_entity *entity,
                lut->lut = NULL;
                spin_unlock_irqrestore(&lut->lock, flags);
 
-               if (dlb)
+               if (dlb) {
                        vsp1_dl_list_add_body(dl, dlb);
+
+                       /* Release our local reference. */
+                       vsp1_dl_body_put(dlb);
+               }
+
                break;
        }
 }