drm: convert crtc and connection_mutex to ww_mutex (v5)

For atomic, it will be quite necessary to not need to care so much
about locking order.  And 'state' gives us a convenient place to stash a
ww_ctx for any sort of update that needs to grab multiple crtc locks.

Because we will want to eventually make locking even more fine grained
(giving locks to planes, connectors, etc), split out drm_modeset_lock
and drm_modeset_acquire_ctx to track acquired locks.

Atomic will use this to keep track of which locks have been acquired
in a transaction.

v1: original
v2: remove a few things not needed until atomic, for now
v3: update for v3 of connection_mutex patch..
v4: squash in docbook
v5: doc tweaks/fixes

Signed-off-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>

9 files changed, 63 insertions, 41 deletions

diff --git a/drivers/gpu/drm/i915/intel_crt.c b/drivers/gpu/drm/i915/intel_crt.c
index 1fc91df58296..5a045d3bd77e 100644
--- a/drivers/gpu/drm/i915/intel_crt.c
+++ b/drivers/gpu/drm/i915/intel_crt.c
@@ -630,6 +630,7 @@ intel_crt_detect(struct drm_connector *connector, bool force)
 	enum intel_display_power_domain power_domain;
 	enum drm_connector_status status;
 	struct intel_load_detect_pipe tmp;
+	struct drm_modeset_acquire_ctx ctx;
 
 	intel_runtime_pm_get(dev_priv);
 
@@ -673,12 +674,12 @@ intel_crt_detect(struct drm_connector *connector, bool force)
 	}
 
 	/* for pre-945g platforms use load detect */
-	if (intel_get_load_detect_pipe(connector, NULL, &tmp)) {
+	if (intel_get_load_detect_pipe(connector, NULL, &tmp, &ctx)) {
 		if (intel_crt_detect_ddc(connector))
 			status = connector_status_connected;
 		else
 			status = intel_crt_load_detect(crt);
-		intel_release_load_detect_pipe(connector, &tmp);
+		intel_release_load_detect_pipe(connector, &tmp, &ctx);
 	} else
 		status = connector_status_unknown;
 
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index c2976ade823f..1ce4ad4626e4 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -2576,7 +2576,7 @@ void intel_display_handle_reset(struct drm_device *dev)
 	for_each_crtc(dev, crtc) {
 		struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
 
-		mutex_lock(&crtc->mutex);
+		drm_modeset_lock(&crtc->mutex, NULL);
 		/*
 		 * FIXME: Once we have proper support for primary planes (and
 		 * disabling them without disabling the entire crtc) allow again
@@ -2587,7 +2587,7 @@ void intel_display_handle_reset(struct drm_device *dev)
 							       crtc->primary->fb,
 							       crtc->x,
 							       crtc->y);
-		mutex_unlock(&crtc->mutex);
+		drm_modeset_unlock(&crtc->mutex);
 	}
 }
 
@@ -8307,7 +8307,8 @@ mode_fits_in_fbdev(struct drm_device *dev,
 
 bool intel_get_load_detect_pipe(struct drm_connector *connector,
 				struct drm_display_mode *mode,
-				struct intel_load_detect_pipe *old)
+				struct intel_load_detect_pipe *old,
+				struct drm_modeset_acquire_ctx *ctx)
 {
 	struct intel_crtc *intel_crtc;
 	struct intel_encoder *intel_encoder =
@@ -8317,13 +8318,19 @@ bool intel_get_load_detect_pipe(struct drm_connector *connector,
 	struct drm_crtc *crtc = NULL;
 	struct drm_device *dev = encoder->dev;
 	struct drm_framebuffer *fb;
-	int i = -1;
+	struct drm_mode_config *config = &dev->mode_config;
+	int ret, i = -1;
 
 	DRM_DEBUG_KMS("[CONNECTOR:%d:%s], [ENCODER:%d:%s]\n",
 		      connector->base.id, connector->name,
 		      encoder->base.id, encoder->name);
 
-	mutex_lock(&dev->mode_config.connection_mutex);
+	drm_modeset_acquire_init(ctx, 0);
+
+retry:
+	ret = drm_modeset_lock(&config->connection_mutex, ctx);
+	if (ret)
+		goto fail_unlock;
 
 	/*
 	 * Algorithm gets a little messy:
@@ -8339,7 +8346,9 @@ bool intel_get_load_detect_pipe(struct drm_connector *connector,
 	if (encoder->crtc) {
 		crtc = encoder->crtc;
 
-		mutex_lock(&crtc->mutex);
+		ret = drm_modeset_lock(&crtc->mutex, ctx);
+		if (ret)
+			goto fail_unlock;
 
 		old->dpms_mode = connector->dpms;
 		old->load_detect_temp = false;
@@ -8367,10 +8376,12 @@ bool intel_get_load_detect_pipe(struct drm_connector *connector,
 	 */
 	if (!crtc) {
 		DRM_DEBUG_KMS("no pipe available for load-detect\n");
-		goto fail_unlock_connector;
+		goto fail_unlock;
 	}
 
-	mutex_lock(&crtc->mutex);
+	ret = drm_modeset_lock(&crtc->mutex, ctx);
+	if (ret)
+		goto fail_unlock;
 	intel_encoder->new_crtc = to_intel_crtc(crtc);
 	to_intel_connector(connector)->new_encoder = intel_encoder;
 
@@ -8420,15 +8431,21 @@ bool intel_get_load_detect_pipe(struct drm_connector *connector,
 		intel_crtc->new_config = &intel_crtc->config;
 	else
 		intel_crtc->new_config = NULL;
-	mutex_unlock(&crtc->mutex);
-fail_unlock_connector:
-	mutex_unlock(&dev->mode_config.connection_mutex);
+fail_unlock:
+	if (ret == -EDEADLK) {
+		drm_modeset_backoff(ctx);
+		goto retry;
+	}
+
+	drm_modeset_drop_locks(ctx);
+	drm_modeset_acquire_fini(ctx);
 
 	return false;
 }
 
 void intel_release_load_detect_pipe(struct drm_connector *connector,
-				    struct intel_load_detect_pipe *old)
+				    struct intel_load_detect_pipe *old,
+				    struct drm_modeset_acquire_ctx *ctx)
 {
 	struct intel_encoder *intel_encoder =
 		intel_attached_encoder(connector);
@@ -8452,8 +8469,7 @@ void intel_release_load_detect_pipe(struct drm_connector *connector,
 			drm_framebuffer_unreference(old->release_fb);
 		}
 
-		mutex_unlock(&crtc->mutex);
-		mutex_unlock(&connector->dev->mode_config.connection_mutex);
+		goto unlock;
 		return;
 	}
 
@@ -8461,8 +8477,9 @@ void intel_release_load_detect_pipe(struct drm_connector *connector,
 	if (old->dpms_mode != DRM_MODE_DPMS_ON)
 		connector->funcs->dpms(connector, old->dpms_mode);
 
-	mutex_unlock(&crtc->mutex);
-	mutex_unlock(&connector->dev->mode_config.connection_mutex);
+unlock:
+	drm_modeset_drop_locks(ctx);
+	drm_modeset_acquire_fini(ctx);
 }
 
 static int i9xx_pll_refclk(struct drm_device *dev,
@@ -10995,7 +11012,7 @@ enum pipe intel_get_pipe_from_connector(struct intel_connector *connector)
 	struct drm_encoder *encoder = connector->base.encoder;
 	struct drm_device *dev = connector->base.dev;
 
-	WARN_ON(!mutex_is_locked(&dev->mode_config.connection_mutex));
+	WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
 
 	if (!encoder)
 		return INVALID_PIPE;
@@ -11805,6 +11822,7 @@ static void intel_enable_pipe_a(struct drm_device *dev)
 	struct intel_connector *connector;
 	struct drm_connector *crt = NULL;
 	struct intel_load_detect_pipe load_detect_temp;
+	struct drm_modeset_acquire_ctx ctx;
 
 	/* We can't just switch on the pipe A, we need to set things up with a
 	 * proper mode and output configuration. As a gross hack, enable pipe A
@@ -11821,8 +11839,8 @@ static void intel_enable_pipe_a(struct drm_device *dev)
 	if (!crt)
 		return;
 
-	if (intel_get_load_detect_pipe(crt, NULL, &load_detect_temp))
-		intel_release_load_detect_pipe(crt, &load_detect_temp);
+	if (intel_get_load_detect_pipe(crt, NULL, &load_detect_temp, &ctx))
+		intel_release_load_detect_pipe(crt, &load_detect_temp, &ctx);
 
 
 }
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index d01bb430b5bc..2d5d9b010073 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1154,7 +1154,7 @@ static void edp_panel_vdd_off_sync(struct intel_dp *intel_dp)
 	u32 pp;
 	u32 pp_stat_reg, pp_ctrl_reg;
 
-	WARN_ON(!mutex_is_locked(&dev->mode_config.connection_mutex));
+	WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
 
 	if (!intel_dp->want_panel_vdd && edp_have_panel_vdd(intel_dp)) {
 		struct intel_digital_port *intel_dig_port =
@@ -1191,9 +1191,9 @@ static void edp_panel_vdd_work(struct work_struct *__work)
 						 struct intel_dp, panel_vdd_work);
 	struct drm_device *dev = intel_dp_to_dev(intel_dp);
 
-	mutex_lock(&dev->mode_config.connection_mutex);
+	drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
 	edp_panel_vdd_off_sync(intel_dp);
-	mutex_unlock(&dev->mode_config.connection_mutex);
+	drm_modeset_unlock(&dev->mode_config.connection_mutex);
 }
 
 static void edp_panel_vdd_off(struct intel_dp *intel_dp, bool sync)
@@ -3666,9 +3666,9 @@ void intel_dp_encoder_destroy(struct drm_encoder *encoder)
 	drm_encoder_cleanup(encoder);
 	if (is_edp(intel_dp)) {
 		cancel_delayed_work_sync(&intel_dp->panel_vdd_work);
-		mutex_lock(&dev->mode_config.connection_mutex);
+		drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
 		edp_panel_vdd_off_sync(intel_dp);
-		mutex_unlock(&dev->mode_config.connection_mutex);
+		drm_modeset_unlock(&dev->mode_config.connection_mutex);
 	}
 	kfree(intel_dig_port);
 }
@@ -4247,9 +4247,9 @@ intel_dp_init_connector(struct intel_digital_port *intel_dig_port,
 		drm_dp_aux_unregister(&intel_dp->aux);
 		if (is_edp(intel_dp)) {
 			cancel_delayed_work_sync(&intel_dp->panel_vdd_work);
-			mutex_lock(&dev->mode_config.connection_mutex);
+			drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
 			edp_panel_vdd_off_sync(intel_dp);
-			mutex_unlock(&dev->mode_config.connection_mutex);
+			drm_modeset_unlock(&dev->mode_config.connection_mutex);
 		}
 		drm_sysfs_connector_remove(connector);
 		drm_connector_cleanup(connector);
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index f1d5897c96cd..0de04983501e 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -748,9 +748,11 @@ void vlv_wait_port_ready(struct drm_i915_private *dev_priv,
 			 struct intel_digital_port *dport);
 bool intel_get_load_detect_pipe(struct drm_connector *connector,
 				struct drm_display_mode *mode,
-				struct intel_load_detect_pipe *old);
+				struct intel_load_detect_pipe *old,
+				struct drm_modeset_acquire_ctx *ctx);
 void intel_release_load_detect_pipe(struct drm_connector *connector,
-				    struct intel_load_detect_pipe *old);
+				    struct intel_load_detect_pipe *old,
+				    struct drm_modeset_acquire_ctx *ctx);
 int intel_pin_and_fence_fb_obj(struct drm_device *dev,
 			       struct drm_i915_gem_object *obj,
 			       struct intel_engine_cs *pipelined);
diff --git a/drivers/gpu/drm/i915/intel_opregion.c b/drivers/gpu/drm/i915/intel_opregion.c
index b812e9d39f38..2e2c71fcc9ed 100644
--- a/drivers/gpu/drm/i915/intel_opregion.c
+++ b/drivers/gpu/drm/i915/intel_opregion.c
@@ -410,7 +410,7 @@ static u32 asle_set_backlight(struct drm_device *dev, u32 bclp)
 	if (bclp > 255)
 		return ASLC_BACKLIGHT_FAILED;
 
-	mutex_lock(&dev->mode_config.connection_mutex);
+	drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
 
 	/*
 	 * Update backlight on all connectors that support backlight (usually
@@ -421,7 +421,7 @@ static u32 asle_set_backlight(struct drm_device *dev, u32 bclp)
 		intel_panel_set_backlight(intel_connector, bclp, 255);
 	iowrite32(DIV_ROUND_UP(bclp * 100, 255) | ASLE_CBLV_VALID, &asle->cblv);
 
-	mutex_unlock(&dev->mode_config.connection_mutex);
+	drm_modeset_unlock(&dev->mode_config.connection_mutex);
 
 
 	return 0;
diff --git a/drivers/gpu/drm/i915/intel_overlay.c b/drivers/gpu/drm/i915/intel_overlay.c
index e97ea33e0117..0396d1312b5c 100644
--- a/drivers/gpu/drm/i915/intel_overlay.c
+++ b/drivers/gpu/drm/i915/intel_overlay.c
@@ -688,7 +688,7 @@ static int intel_overlay_do_put_image(struct intel_overlay *overlay,
 	u32 swidth, swidthsw, sheight, ostride;
 
 	BUG_ON(!mutex_is_locked(&dev->struct_mutex));
-	BUG_ON(!mutex_is_locked(&dev->mode_config.connection_mutex));
+	BUG_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
 	BUG_ON(!overlay);
 
 	ret = intel_overlay_release_old_vid(overlay);
@@ -793,7 +793,7 @@ int intel_overlay_switch_off(struct intel_overlay *overlay)
 	int ret;
 
 	BUG_ON(!mutex_is_locked(&dev->struct_mutex));
-	BUG_ON(!mutex_is_locked(&dev->mode_config.connection_mutex));
+	BUG_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
 
 	ret = intel_overlay_recover_from_interrupt(overlay);
 	if (ret != 0)
diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c
index d4d415665475..2e1338a5d488 100644
--- a/drivers/gpu/drm/i915/intel_panel.c
+++ b/drivers/gpu/drm/i915/intel_panel.c
@@ -876,12 +876,12 @@ static int intel_backlight_device_update_status(struct backlight_device *bd)
 	struct intel_connector *connector = bl_get_data(bd);
 	struct drm_device *dev = connector->base.dev;
 
-	mutex_lock(&dev->mode_config.connection_mutex);
+	drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
 	DRM_DEBUG_KMS("updating intel_backlight, brightness=%d/%d\n",
 		      bd->props.brightness, bd->props.max_brightness);
 	intel_panel_set_backlight(connector, bd->props.brightness,
 				  bd->props.max_brightness);
-	mutex_unlock(&dev->mode_config.connection_mutex);
+	drm_modeset_unlock(&dev->mode_config.connection_mutex);
 	return 0;
 }
 
@@ -893,9 +893,9 @@ static int intel_backlight_device_get_brightness(struct backlight_device *bd)
 	int ret;
 
 	intel_runtime_pm_get(dev_priv);
-	mutex_lock(&dev->mode_config.connection_mutex);
+	drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
 	ret = intel_panel_get_backlight(connector);
-	mutex_unlock(&dev->mode_config.connection_mutex);
+	drm_modeset_unlock(&dev->mode_config.connection_mutex);
 	intel_runtime_pm_put(dev_priv);
 
 	return ret;
diff --git a/drivers/gpu/drm/i915/intel_sprite.c b/drivers/gpu/drm/i915/intel_sprite.c
index d6acd6bd0bf0..1b66ddcdfb33 100644
--- a/drivers/gpu/drm/i915/intel_sprite.c
+++ b/drivers/gpu/drm/i915/intel_sprite.c
@@ -55,7 +55,7 @@ static bool intel_pipe_update_start(struct intel_crtc *crtc, uint32_t *start_vbl
 	int scanline, min, max, vblank_start;
 	DEFINE_WAIT(wait);
 
-	WARN_ON(!mutex_is_locked(&crtc->base.mutex));
+	WARN_ON(!drm_modeset_is_locked(&crtc->base.mutex));
 
 	vblank_start = mode->crtc_vblank_start;
 	if (mode->flags & DRM_MODE_FLAG_INTERLACE)
diff --git a/drivers/gpu/drm/i915/intel_tv.c b/drivers/gpu/drm/i915/intel_tv.c
index 25850a86d70c..67c6c9a2eb1c 100644
--- a/drivers/gpu/drm/i915/intel_tv.c
+++ b/drivers/gpu/drm/i915/intel_tv.c
@@ -1321,10 +1321,11 @@ intel_tv_detect(struct drm_connector *connector, bool force)
 
 	if (force) {
 		struct intel_load_detect_pipe tmp;
+		struct drm_modeset_acquire_ctx ctx;
 
-		if (intel_get_load_detect_pipe(connector, &mode, &tmp)) {
+		if (intel_get_load_detect_pipe(connector, &mode, &tmp, &ctx)) {
 			type = intel_tv_detect_type(intel_tv, connector);
-			intel_release_load_detect_pipe(connector, &tmp);
+			intel_release_load_detect_pipe(connector, &tmp, &ctx);
 		} else
 			return connector_status_unknown;
 	} else