OMAP: DSS2: OMAPFB: Add locking for memory regions

Add locking to the memory regions to make sure the memory region size
won't be changed while some other piece of code is performing some
checks or setup based on that information.

Signed-off-by: Ville Syrjälä <ville.syrjala@nokia.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@nokia.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/drivers/video/omap2/omapfb/omapfb.h b/drivers/video/omap2/omapfb/omapfb.h
index 02f1ba9b228c..db3aef5172c5 100644
--- a/drivers/video/omap2/omapfb/omapfb.h
+++ b/drivers/video/omap2/omapfb/omapfb.h
@@ -52,6 +52,8 @@ struct omapfb2_mem_region {
         u8              type;           /* OMAPFB_PLANE_MEM_* */
         bool            alloc;          /* allocated by the driver */
         bool            map;            /* kernel mapped by the driver */
+        struct mutex    mtx;
+        unsigned int    ref;
         atomic_t        map_count;
 };
 
@@ -159,4 +161,20 @@ static inline int omapfb_overlay_enable(struct omap_overlay *ovl,
         return ovl->set_overlay_info(ovl, &info);
 }
 
+static inline struct omapfb2_mem_region *
+omapfb_get_mem_region(struct omapfb2_mem_region *rg)
+{
+        mutex_lock(&rg->mtx);
+        rg->ref++;
+        mutex_unlock(&rg->mtx);
+        return rg;
+}
+
+static inline void omapfb_put_mem_region(struct omapfb2_mem_region *rg)
+{
+        mutex_lock(&rg->mtx);
+        rg->ref--;
+        mutex_unlock(&rg->mtx);
+}
+
 #endif