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, 33 insertions, 11 deletions

diff --git a/drivers/video/omap2/omapfb/omapfb-ioctl.c b/drivers/video/omap2/omapfb/omapfb-ioctl.c
index 6635bd75affa..69bcbfca47f6 100644
--- a/drivers/video/omap2/omapfb/omapfb-ioctl.c
+++ b/drivers/video/omap2/omapfb/omapfb-ioctl.c
@@ -55,7 +55,7 @@ static struct omapfb2_mem_region *get_mem_region(struct omapfb_info *ofbi,
 	if (mem_idx >= fbdev->num_fbs)
 		return NULL;
 
-	return &fbdev->regions[mem_idx];
+	return omapfb_get_mem_region(&fbdev->regions[mem_idx]);
 }
 
 static int omapfb_setup_plane(struct fb_info *fbi, struct omapfb_plane_info *pi)
@@ -77,11 +77,11 @@ static int omapfb_setup_plane(struct fb_info *fbi, struct omapfb_plane_info *pi)
 	/* XXX uses only the first overlay */
 	ovl = ofbi->overlays[0];
 
-	old_rg = ofbi->region;
+	old_rg = omapfb_get_mem_region(ofbi->region);
 	new_rg = get_mem_region(ofbi, pi->mem_idx);
 	if (!new_rg) {
 		r = -EINVAL;
-		goto out;
+		goto put_old;
 	}
 
 	if (pi->enabled && !new_rg->size) {
@@ -90,7 +90,7 @@ static int omapfb_setup_plane(struct fb_info *fbi, struct omapfb_plane_info *pi)
 		 * until it's reallocated.
 		 */
 		r = -EINVAL;
-		goto out;
+		goto put_new;
 	}
 
 	ovl->get_overlay_info(ovl, &old_info);
@@ -135,6 +135,9 @@ static int omapfb_setup_plane(struct fb_info *fbi, struct omapfb_plane_info *pi)
 	if (ovl->manager)
 		ovl->manager->apply(ovl->manager);
 
+	omapfb_put_mem_region(new_rg);
+	omapfb_put_mem_region(old_rg);
+
 	return 0;
 
  undo:
@@ -144,6 +147,10 @@ static int omapfb_setup_plane(struct fb_info *fbi, struct omapfb_plane_info *pi)
 	}
 
 	ovl->set_overlay_info(ovl, &old_info);
+ put_new:
+	omapfb_put_mem_region(new_rg);
+ put_old:
+	omapfb_put_mem_region(old_rg);
  out:
 	dev_err(fbdev->dev, "setup_plane failed\n");
 
@@ -181,7 +188,7 @@ static int omapfb_setup_mem(struct fb_info *fbi, struct omapfb_mem_info *mi)
 	struct omapfb_info *ofbi = FB2OFB(fbi);
 	struct omapfb2_device *fbdev = ofbi->fbdev;
 	struct omapfb2_mem_region *rg;
-	int r, i;
+	int r = 0, i;
 	size_t size;
 
 	if (mi->type > OMAPFB_MEMTYPE_MAX)
@@ -191,8 +198,18 @@ static int omapfb_setup_mem(struct fb_info *fbi, struct omapfb_mem_info *mi)
 
 	rg = ofbi->region;
 
-	if (atomic_read(&rg->map_count))
-		return -EBUSY;
+	/* FIXME probably should be a rwsem ... */
+	mutex_lock(&rg->mtx);
+	while (rg->ref) {
+		mutex_unlock(&rg->mtx);
+		schedule();
+		mutex_lock(&rg->mtx);
+	}
+
+	if (atomic_read(&rg->map_count)) {
+		r = -EBUSY;
+		goto out;
+	}
 
 	for (i = 0; i < fbdev->num_fbs; i++) {
 		struct omapfb_info *ofbi2 = FB2OFB(fbdev->fbs[i]);
@@ -204,7 +221,7 @@ static int omapfb_setup_mem(struct fb_info *fbi, struct omapfb_mem_info *mi)
 		for (j = 0; j < ofbi2->num_overlays; j++) {
 			if (ofbi2->overlays[j]->info.enabled) {
 				r = -EBUSY;
-				return r;
+				goto out;
 			}
 		}
 	}
@@ -213,11 +230,14 @@ static int omapfb_setup_mem(struct fb_info *fbi, struct omapfb_mem_info *mi)
 		r = omapfb_realloc_fbmem(fbi, size, mi->type);
 		if (r) {
 			dev_err(fbdev->dev, "realloc fbmem failed\n");
-			return r;
+			goto out;
 		}
 	}
 
-	return 0;
+ out:
+	mutex_unlock(&rg->mtx);
+
+	return r;
 }
 
 static int omapfb_query_mem(struct fb_info *fbi, struct omapfb_mem_info *mi)
@@ -225,12 +245,14 @@ static int omapfb_query_mem(struct fb_info *fbi, struct omapfb_mem_info *mi)
 	struct omapfb_info *ofbi = FB2OFB(fbi);
 	struct omapfb2_mem_region *rg;
 
-	rg = ofbi->region;
+	rg = omapfb_get_mem_region(ofbi->region);
 	memset(mi, 0, sizeof(*mi));
 
 	mi->size = rg->size;
 	mi->type = rg->type;
 
+	omapfb_put_mem_region(rg);
+
 	return 0;
 }