1 files changed, 101 insertions, 54 deletions

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 25edf670867c..4b8119510687 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -371,9 +371,9 @@ static void drm_fb_helper_resume_worker(struct work_struct *work)
 	console_unlock();
 }
 
-static void drm_fb_helper_dirty_blit_real(struct drm_fb_helper *fb_helper,
-					  struct drm_clip_rect *clip,
-					  struct dma_buf_map *dst)
+static void drm_fb_helper_damage_blit_real(struct drm_fb_helper *fb_helper,
+					   struct drm_clip_rect *clip,
+					   struct dma_buf_map *dst)
 {
 	struct drm_framebuffer *fb = fb_helper->fb;
 	unsigned int cpp = fb->format->cpp[0];
@@ -391,40 +391,86 @@ static void drm_fb_helper_dirty_blit_real(struct drm_fb_helper *fb_helper,
 	}
 }
 
-static void drm_fb_helper_dirty_work(struct work_struct *work)
+static int drm_fb_helper_damage_blit(struct drm_fb_helper *fb_helper,
+				     struct drm_clip_rect *clip)
+{
+	struct drm_client_buffer *buffer = fb_helper->buffer;
+	struct dma_buf_map map, dst;
+	int ret;
+
+	/*
+	 * We have to pin the client buffer to its current location while
+	 * flushing the shadow buffer. In the general case, concurrent
+	 * modesetting operations could try to move the buffer and would
+	 * fail. The modeset has to be serialized by acquiring the reservation
+	 * object of the underlying BO here.
+	 *
+	 * For fbdev emulation, we only have to protect against fbdev modeset
+	 * operations. Nothing else will involve the client buffer's BO. So it
+	 * is sufficient to acquire struct drm_fb_helper.lock here.
+	 */
+	mutex_lock(&fb_helper->lock);
+
+	ret = drm_client_buffer_vmap(buffer, &map);
+	if (ret)
+		goto out;
+
+	dst = map;
+	drm_fb_helper_damage_blit_real(fb_helper, clip, &dst);
+
+	drm_client_buffer_vunmap(buffer);
+
+out:
+	mutex_unlock(&fb_helper->lock);
+
+	return ret;
+}
+
+static void drm_fb_helper_damage_work(struct work_struct *work)
 {
 	struct drm_fb_helper *helper = container_of(work, struct drm_fb_helper,
-						    dirty_work);
-	struct drm_clip_rect *clip = &helper->dirty_clip;
+						    damage_work);
+	struct drm_device *dev = helper->dev;
+	struct drm_clip_rect *clip = &helper->damage_clip;
 	struct drm_clip_rect clip_copy;
 	unsigned long flags;
-	struct dma_buf_map map;
 	int ret;
 
-	spin_lock_irqsave(&helper->dirty_lock, flags);
+	spin_lock_irqsave(&helper->damage_lock, flags);
 	clip_copy = *clip;
 	clip->x1 = clip->y1 = ~0;
 	clip->x2 = clip->y2 = 0;
-	spin_unlock_irqrestore(&helper->dirty_lock, flags);
+	spin_unlock_irqrestore(&helper->damage_lock, flags);
 
-	/* call dirty callback only when it has been really touched */
-	if (clip_copy.x1 < clip_copy.x2 && clip_copy.y1 < clip_copy.y2) {
-
-		/* Generic fbdev uses a shadow buffer */
-		if (helper->buffer) {
-			ret = drm_client_buffer_vmap(helper->buffer, &map);
-			if (ret)
-				return;
-			drm_fb_helper_dirty_blit_real(helper, &clip_copy, &map);
-		}
+	/* Call damage handlers only if necessary */
+	if (!(clip_copy.x1 < clip_copy.x2 && clip_copy.y1 < clip_copy.y2))
+		return;
 
-		if (helper->fb->funcs->dirty)
-			helper->fb->funcs->dirty(helper->fb, NULL, 0, 0,
-						 &clip_copy, 1);
+	if (helper->buffer) {
+		ret = drm_fb_helper_damage_blit(helper, &clip_copy);
+		if (drm_WARN_ONCE(dev, ret, "Damage blitter failed: ret=%d\n", ret))
+			goto err;
+	}
 
-		if (helper->buffer)
-			drm_client_buffer_vunmap(helper->buffer);
+	if (helper->fb->funcs->dirty) {
+		ret = helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, &clip_copy, 1);
+		if (drm_WARN_ONCE(dev, ret, "Dirty helper failed: ret=%d\n", ret))
+			goto err;
 	}
+
+	return;
+
+err:
+	/*
+	 * Restore damage clip rectangle on errors. The next run
+	 * of the damage worker will perform the update.
+	 */
+	spin_lock_irqsave(&helper->damage_lock, flags);
+	clip->x1 = min_t(u32, clip->x1, clip_copy.x1);
+	clip->y1 = min_t(u32, clip->y1, clip_copy.y1);
+	clip->x2 = max_t(u32, clip->x2, clip_copy.x2);
+	clip->y2 = max_t(u32, clip->y2, clip_copy.y2);
+	spin_unlock_irqrestore(&helper->damage_lock, flags);
 }
 
 /**
@@ -440,10 +486,10 @@ void drm_fb_helper_prepare(struct drm_device *dev, struct drm_fb_helper *helper,
 			   const struct drm_fb_helper_funcs *funcs)
 {
 	INIT_LIST_HEAD(&helper->kernel_fb_list);
-	spin_lock_init(&helper->dirty_lock);
+	spin_lock_init(&helper->damage_lock);
 	INIT_WORK(&helper->resume_work, drm_fb_helper_resume_worker);
-	INIT_WORK(&helper->dirty_work, drm_fb_helper_dirty_work);
-	helper->dirty_clip.x1 = helper->dirty_clip.y1 = ~0;
+	INIT_WORK(&helper->damage_work, drm_fb_helper_damage_work);
+	helper->damage_clip.x1 = helper->damage_clip.y1 = ~0;
 	mutex_init(&helper->lock);
 	helper->funcs = funcs;
 	helper->dev = dev;
@@ -579,7 +625,7 @@ void drm_fb_helper_fini(struct drm_fb_helper *fb_helper)
 		return;
 
 	cancel_work_sync(&fb_helper->resume_work);
-	cancel_work_sync(&fb_helper->dirty_work);
+	cancel_work_sync(&fb_helper->damage_work);
 
 	info = fb_helper->fbdev;
 	if (info) {
@@ -614,30 +660,30 @@ static bool drm_fbdev_use_shadow_fb(struct drm_fb_helper *fb_helper)
 	       fb->funcs->dirty;
 }
 
-static void drm_fb_helper_dirty(struct fb_info *info, u32 x, u32 y,
-				u32 width, u32 height)
+static void drm_fb_helper_damage(struct fb_info *info, u32 x, u32 y,
+				 u32 width, u32 height)
 {
 	struct drm_fb_helper *helper = info->par;
-	struct drm_clip_rect *clip = &helper->dirty_clip;
+	struct drm_clip_rect *clip = &helper->damage_clip;
 	unsigned long flags;
 
 	if (!drm_fbdev_use_shadow_fb(helper))
 		return;
 
-	spin_lock_irqsave(&helper->dirty_lock, flags);
+	spin_lock_irqsave(&helper->damage_lock, flags);
 	clip->x1 = min_t(u32, clip->x1, x);
 	clip->y1 = min_t(u32, clip->y1, y);
 	clip->x2 = max_t(u32, clip->x2, x + width);
 	clip->y2 = max_t(u32, clip->y2, y + height);
-	spin_unlock_irqrestore(&helper->dirty_lock, flags);
+	spin_unlock_irqrestore(&helper->damage_lock, flags);
 
-	schedule_work(&helper->dirty_work);
+	schedule_work(&helper->damage_work);
 }
 
 /**
  * drm_fb_helper_deferred_io() - fbdev deferred_io callback function
  * @info: fb_info struct pointer
- * @pagelist: list of dirty mmap framebuffer pages
+ * @pagelist: list of mmap framebuffer pages that have to be flushed
  *
  * This function is used as the &fb_deferred_io.deferred_io
  * callback function for flushing the fbdev mmap writes.
@@ -662,7 +708,7 @@ void drm_fb_helper_deferred_io(struct fb_info *info,
 		y1 = min / info->fix.line_length;
 		y2 = min_t(u32, DIV_ROUND_UP(max, info->fix.line_length),
 			   info->var.yres);
-		drm_fb_helper_dirty(info, 0, y1, info->var.xres, y2 - y1);
+		drm_fb_helper_damage(info, 0, y1, info->var.xres, y2 - y1);
 	}
 }
 EXPORT_SYMBOL(drm_fb_helper_deferred_io);
@@ -699,8 +745,7 @@ ssize_t drm_fb_helper_sys_write(struct fb_info *info, const char __user *buf,
 
 	ret = fb_sys_write(info, buf, count, ppos);
 	if (ret > 0)
-		drm_fb_helper_dirty(info, 0, 0, info->var.xres,
-				    info->var.yres);
+		drm_fb_helper_damage(info, 0, 0, info->var.xres, info->var.yres);
 
 	return ret;
 }
@@ -717,8 +762,7 @@ void drm_fb_helper_sys_fillrect(struct fb_info *info,
 				const struct fb_fillrect *rect)
 {
 	sys_fillrect(info, rect);
-	drm_fb_helper_dirty(info, rect->dx, rect->dy,
-			    rect->width, rect->height);
+	drm_fb_helper_damage(info, rect->dx, rect->dy, rect->width, rect->height);
 }
 EXPORT_SYMBOL(drm_fb_helper_sys_fillrect);
 
@@ -733,8 +777,7 @@ void drm_fb_helper_sys_copyarea(struct fb_info *info,
 				const struct fb_copyarea *area)
 {
 	sys_copyarea(info, area);
-	drm_fb_helper_dirty(info, area->dx, area->dy,
-			    area->width, area->height);
+	drm_fb_helper_damage(info, area->dx, area->dy, area->width, area->height);
 }
 EXPORT_SYMBOL(drm_fb_helper_sys_copyarea);
 
@@ -749,8 +792,7 @@ void drm_fb_helper_sys_imageblit(struct fb_info *info,
 				 const struct fb_image *image)
 {
 	sys_imageblit(info, image);
-	drm_fb_helper_dirty(info, image->dx, image->dy,
-			    image->width, image->height);
+	drm_fb_helper_damage(info, image->dx, image->dy, image->width, image->height);
 }
 EXPORT_SYMBOL(drm_fb_helper_sys_imageblit);
 
@@ -765,8 +807,7 @@ void drm_fb_helper_cfb_fillrect(struct fb_info *info,
 				const struct fb_fillrect *rect)
 {
 	cfb_fillrect(info, rect);
-	drm_fb_helper_dirty(info, rect->dx, rect->dy,
-			    rect->width, rect->height);
+	drm_fb_helper_damage(info, rect->dx, rect->dy, rect->width, rect->height);
 }
 EXPORT_SYMBOL(drm_fb_helper_cfb_fillrect);
 
@@ -781,8 +822,7 @@ void drm_fb_helper_cfb_copyarea(struct fb_info *info,
 				const struct fb_copyarea *area)
 {
 	cfb_copyarea(info, area);
-	drm_fb_helper_dirty(info, area->dx, area->dy,
-			    area->width, area->height);
+	drm_fb_helper_damage(info, area->dx, area->dy, area->width, area->height);
 }
 EXPORT_SYMBOL(drm_fb_helper_cfb_copyarea);
 
@@ -797,8 +837,7 @@ void drm_fb_helper_cfb_imageblit(struct fb_info *info,
 				 const struct fb_image *image)
 {
 	cfb_imageblit(info, image);
-	drm_fb_helper_dirty(info, image->dx, image->dy,
-			    image->width, image->height);
+	drm_fb_helper_damage(info, image->dx, image->dy, image->width, image->height);
 }
 EXPORT_SYMBOL(drm_fb_helper_cfb_imageblit);
 
@@ -1988,14 +2027,19 @@ static void drm_fbdev_cleanup(struct drm_fb_helper *fb_helper)
 	if (!fb_helper->dev)
 		return;
 
-	if (fbi && fbi->fbdefio) {
-		fb_deferred_io_cleanup(fbi);
-		shadow = fbi->screen_buffer;
+	if (fbi) {
+		if (fbi->fbdefio)
+			fb_deferred_io_cleanup(fbi);
+		if (drm_fbdev_use_shadow_fb(fb_helper))
+			shadow = fbi->screen_buffer;
 	}
 
 	drm_fb_helper_fini(fb_helper);
 
-	vfree(shadow);
+	if (shadow)
+		vfree(shadow);
+	else
+		drm_client_buffer_vunmap(fb_helper->buffer);
 
 	drm_client_framebuffer_delete(fb_helper->buffer);
 }
@@ -2189,6 +2233,9 @@ static ssize_t drm_fbdev_fb_write(struct fb_info *info, const char __user *buf,
 	if (ret > 0)
 		*ppos += ret;
 
+	if (ret > 0)
+		drm_fb_helper_damage(info, 0, 0, info->var.xres_virtual, info->var.yres_virtual);
+
 	return ret ? ret : err;
 }