drm: add drm_modeset_lock|unlock_all

This is the first step towards introducing the new modeset locking
scheme. The plan is to put helper functions into place at all the
right places step-by-step, so that the final patch to switch on the
new locking scheme doesn't need to touch every single driver.

This helper here will serve as the shotgun solutions for all places
where a more fine-grained locking isn't (yet) implemented.

v2: Fixup kerneldoc for unlock_all.
Reviewed-by: Rob Clark <rob@ti.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/drm_crtc_helper.c

@@ -980,7 +980,7 @@ static void output_poll_execute(struct work_struct *work)
 	if (!drm_kms_helper_poll)
 		return;
 
-	mutex_lock(&dev->mode_config.mutex);
+	drm_modeset_lock_all(dev);
 	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
 
 		/* Ignore forced connectors. */
@@ -1010,7 +1010,7 @@ static void output_poll_execute(struct work_struct *work)
 			changed = true;
 	}
 
-	mutex_unlock(&dev->mode_config.mutex);
+	drm_modeset_unlock_all(dev);
 
 	if (changed)
 		drm_kms_helper_hotplug_event(dev);
@@ -1070,7 +1070,7 @@ void drm_helper_hpd_irq_event(struct drm_device *dev)
 	if (!dev->mode_config.poll_enabled)
 		return;
 
-	mutex_lock(&dev->mode_config.mutex);
+	drm_modeset_lock_all(dev);
 	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
 
 		/* Only handle HPD capable connectors. */
@@ -1088,7 +1088,7 @@ void drm_helper_hpd_irq_event(struct drm_device *dev)
 			changed = true;
 	}
 
-	mutex_unlock(&dev->mode_config.mutex);
+	drm_modeset_unlock_all(dev);
 
 	if (changed)
 		drm_kms_helper_hotplug_event(dev);

drivers/gpu/drm/drm_fb_helper.c

@@ -337,7 +337,7 @@ static void drm_fb_helper_dpms(struct fb_info *info, int dpms_mode)
 	/*
 	 * For each CRTC in this fb, turn the connectors on/off.
 	 */
-	mutex_lock(&dev->mode_config.mutex);
+	drm_modeset_lock_all(dev);
 	for (i = 0; i < fb_helper->crtc_count; i++) {
 		crtc = fb_helper->crtc_info[i].mode_set.crtc;
 
@@ -352,7 +352,7 @@ static void drm_fb_helper_dpms(struct fb_info *info, int dpms_mode)
 				dev->mode_config.dpms_property, dpms_mode);
 		}
 	}
-	mutex_unlock(&dev->mode_config.mutex);
+	drm_modeset_unlock_all(dev);
 }
 
 int drm_fb_helper_blank(int blank, struct fb_info *info)
@@ -672,16 +672,16 @@ int drm_fb_helper_set_par(struct fb_info *info)
 		return -EINVAL;
 	}
 
-	mutex_lock(&dev->mode_config.mutex);
+	drm_modeset_lock_all(dev);
 	for (i = 0; i < fb_helper->crtc_count; i++) {
 		crtc = fb_helper->crtc_info[i].mode_set.crtc;
 		ret = drm_mode_set_config_internal(&fb_helper->crtc_info[i].mode_set);
 		if (ret) {
-			mutex_unlock(&dev->mode_config.mutex);
+			drm_modeset_unlock_all(dev);
 			return ret;
 		}
 	}
-	mutex_unlock(&dev->mode_config.mutex);
+	drm_modeset_unlock_all(dev);
 
 	if (fb_helper->delayed_hotplug) {
 		fb_helper->delayed_hotplug = false;
@@ -701,7 +701,7 @@ int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
 	int ret = 0;
 	int i;
 
-	mutex_lock(&dev->mode_config.mutex);
+	drm_modeset_lock_all(dev);
 	for (i = 0; i < fb_helper->crtc_count; i++) {
 		crtc = fb_helper->crtc_info[i].mode_set.crtc;
 
@@ -718,7 +718,7 @@ int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
 			}
 		}
 	}
-	mutex_unlock(&dev->mode_config.mutex);
+	drm_modeset_unlock_all(dev);
 	return ret;
 }
 EXPORT_SYMBOL(drm_fb_helper_pan_display);
@@ -1375,7 +1375,7 @@ int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
 	if (!fb_helper->fb)
 		return 0;
 
-	mutex_lock(&dev->mode_config.mutex);
+	drm_modeset_lock_all(dev);
 	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
 		if (crtc->fb)
 			crtcs_bound++;
@@ -1385,7 +1385,7 @@ int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
 
 	if (bound < crtcs_bound) {
 		fb_helper->delayed_hotplug = true;
-		mutex_unlock(&dev->mode_config.mutex);
+		drm_modeset_unlock_all(dev);
 		return 0;
 	}
 	DRM_DEBUG_KMS("\n");
@@ -1397,7 +1397,7 @@ int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
 	count = drm_fb_helper_probe_connector_modes(fb_helper, max_width,
 						    max_height);
 	drm_setup_crtcs(fb_helper);
-	mutex_unlock(&dev->mode_config.mutex);
+	drm_modeset_unlock_all(dev);
 
 	return drm_fb_helper_single_fb_probe(fb_helper, bpp_sel);
 }

include/drm/drm_crtc.h

@@ -842,6 +842,9 @@ struct drm_prop_enum_list {
 	char *name;
 };
 
+extern void drm_modeset_lock_all(struct drm_device *dev);
+extern void drm_modeset_unlock_all(struct drm_device *dev);
+
 extern int drm_crtc_init(struct drm_device *dev,
 			 struct drm_crtc *crtc,
 			 const struct drm_crtc_funcs *funcs);