drm/i915: Convert flip_work to a list.

This will be required to allow more than 1 update in the future.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463490484-19540-10-git-send-email-maarten.lankhorst@linux.intel.comReviewed-by: Patrik Jakobsson <patrik.jakobsson@linux.intel.com>

drivers/gpu/drm/i915/i915_debugfs.c

@@ -592,29 +592,13 @@ static int i915_gem_gtt_info(struct seq_file *m, void *data)
 	return 0;
 }
 
-static int i915_gem_pageflip_info(struct seq_file *m, void *data)
+static void i915_dump_pageflip(struct seq_file *m,
+			       struct drm_i915_private *dev_priv,
+			       struct intel_crtc *crtc,
+			       struct intel_flip_work *work)
 {
-	struct drm_info_node *node = m->private;
-	struct drm_device *dev = node->minor->dev;
-	struct drm_i915_private *dev_priv = dev->dev_private;
-	struct intel_crtc *crtc;
-	int ret;
-
-	ret = mutex_lock_interruptible(&dev->struct_mutex);
-	if (ret)
-		return ret;
-
-	for_each_intel_crtc(dev, crtc) {
 	const char pipe = pipe_name(crtc->pipe);
 	const char plane = plane_name(crtc->plane);
-		struct intel_flip_work *work;
-
-		spin_lock_irq(&dev->event_lock);
-		work = crtc->flip_work;
-		if (work == NULL) {
-			seq_printf(m, "No flip due on pipe %c (plane %c)\n",
-				   pipe, plane);
-		} else {
 	u32 pending;
 	u32 addr;
 
@@ -643,7 +627,7 @@ static int i915_gem_pageflip_info(struct seq_file *m, void *data)
 		   intel_crtc_get_vblank_counter(crtc));
 	seq_printf(m, "%d prepares\n", atomic_read(&work->pending));
 
-			if (INTEL_INFO(dev)->gen >= 4)
+	if (INTEL_INFO(dev_priv)->gen >= 4)
 		addr = I915_HI_DISPBASE(I915_READ(DSPSURF(crtc->plane)));
 	else
 		addr = I915_READ(DSPADDR(crtc->plane));
@@ -653,6 +637,34 @@ static int i915_gem_pageflip_info(struct seq_file *m, void *data)
 		seq_printf(m, "New framebuffer address 0x%08lx\n", (long)work->gtt_offset);
 		seq_printf(m, "MMIO update completed? %d\n",  addr == work->gtt_offset);
 	}
+}
+
+static int i915_gem_pageflip_info(struct seq_file *m, void *data)
+{
+	struct drm_info_node *node = m->private;
+	struct drm_device *dev = node->minor->dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_crtc *crtc;
+	int ret;
+
+	ret = mutex_lock_interruptible(&dev->struct_mutex);
+	if (ret)
+		return ret;
+
+	for_each_intel_crtc(dev, crtc) {
+		const char pipe = pipe_name(crtc->pipe);
+		const char plane = plane_name(crtc->plane);
+		struct intel_flip_work *work;
+
+		spin_lock_irq(&dev->event_lock);
+		if (list_empty(&crtc->flip_work)) {
+			seq_printf(m, "No flip due on pipe %c (plane %c)\n",
+				   pipe, plane);
+		} else {
+			list_for_each_entry(work, &crtc->flip_work, head) {
+				i915_dump_pageflip(m, dev_priv, crtc, work);
+				seq_puts(m, "\n");
+			}
 		}
 		spin_unlock_irq(&dev->event_lock);
 	}

drivers/gpu/drm/i915/i915_drv.h

@@ -622,7 +622,7 @@ struct drm_i915_display_funcs {
 			  struct drm_framebuffer *fb,
 			  struct drm_i915_gem_object *obj,
 			  struct drm_i915_gem_request *req,
-			  uint32_t flags);
+			  uint64_t gtt_offset);
 	void (*hpd_irq_setup)(struct drm_i915_private *dev_priv);
 	/* clock updates for mode set */
 	/* cursor updates */

drivers/gpu/drm/i915/intel_display.c

@@ -3213,17 +3213,12 @@ static bool intel_crtc_has_pending_flip(struct drm_crtc *crtc)
 	struct drm_device *dev = crtc->dev;
 	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
 	unsigned reset_counter;
-	bool pending;
 
 	reset_counter = i915_reset_counter(&to_i915(dev)->gpu_error);
 	if (intel_crtc->reset_counter != reset_counter)
 		return false;
 
-	spin_lock_irq(&dev->event_lock);
-	pending = to_intel_crtc(crtc)->flip_work != NULL;
-	spin_unlock_irq(&dev->event_lock);
-
-	return pending;
+	return !list_empty_careful(&to_intel_crtc(crtc)->flip_work);
 }
 
 static void intel_update_pipe_config(struct intel_crtc *crtc,
@@ -3799,7 +3794,7 @@ bool intel_has_pending_fb_unpin(struct drm_device *dev)
 		if (atomic_read(&crtc->unpin_work_count) == 0)
 			continue;
 
-		if (crtc->flip_work)
+		if (!list_empty_careful(&crtc->flip_work))
 			intel_wait_for_vblank(dev, crtc->pipe);
 
 		return true;
@@ -3808,12 +3803,11 @@ bool intel_has_pending_fb_unpin(struct drm_device *dev)
 	return false;
 }
 
-static void page_flip_completed(struct intel_crtc *intel_crtc)
+static void page_flip_completed(struct intel_crtc *intel_crtc, struct intel_flip_work *work)
 {
 	struct drm_i915_private *dev_priv = to_i915(intel_crtc->base.dev);
-	struct intel_flip_work *work = intel_crtc->flip_work;
 
-	intel_crtc->flip_work = NULL;
+	list_del_init(&work->head);
 
 	if (work->event)
 		drm_crtc_send_vblank_event(&intel_crtc->base, work->event);
@@ -3848,10 +3842,16 @@ static int intel_crtc_wait_for_pending_flips(struct drm_crtc *crtc)
 		struct intel_flip_work *work;
 
 		spin_lock_irq(&dev->event_lock);
-		work = intel_crtc->flip_work;
+
+		/*
+		 * If we're waiting for page flips, it's the first
+		 * flip on the list that's stuck.
+		 */
+		work = list_first_entry_or_null(&intel_crtc->flip_work,
+						struct intel_flip_work, head);
 		if (work && !is_mmio_work(work)) {
 			WARN_ONCE(1, "Removing stuck page flip\n");
-			page_flip_completed(intel_crtc);
+			page_flip_completed(intel_crtc, work);
 		}
 		spin_unlock_irq(&dev->event_lock);
 	}
@@ -6232,7 +6232,7 @@ static void intel_crtc_disable_noatomic(struct drm_crtc *crtc)
 		return;
 
 	if (to_intel_plane_state(crtc->primary->state)->visible) {
-		WARN_ON(intel_crtc->flip_work);
+		WARN_ON(list_empty(&intel_crtc->flip_work));
 
 		intel_pre_disable_primary_noatomic(crtc);
 
@@ -10831,15 +10831,19 @@ static void intel_crtc_destroy(struct drm_crtc *crtc)
 	struct intel_flip_work *work;
 
 	spin_lock_irq(&dev->event_lock);
-	work = intel_crtc->flip_work;
-	intel_crtc->flip_work = NULL;
+	while (!list_empty(&intel_crtc->flip_work)) {
+		work = list_first_entry(&intel_crtc->flip_work,
+					struct intel_flip_work, head);
+		list_del_init(&work->head);
 		spin_unlock_irq(&dev->event_lock);
 
-	if (work) {
 		cancel_work_sync(&work->mmio_work);
 		cancel_work_sync(&work->unpin_work);
 		kfree(work);
+
+		spin_lock_irq(&dev->event_lock);
 	}
+	spin_unlock_irq(&dev->event_lock);
 
 	drm_crtc_cleanup(crtc);
 
@@ -10924,9 +10928,9 @@ static bool __pageflip_finished_cs(struct intel_crtc *crtc,
 	 * anyway, we don't really care.
 	 */
 	return (I915_READ(DSPSURFLIVE(crtc->plane)) & ~0xfff) ==
-		crtc->flip_work->gtt_offset &&
+		work->gtt_offset &&
 		g4x_flip_count_after_eq(I915_READ(PIPE_FLIPCOUNT_G4X(crtc->pipe)),
-				    crtc->flip_work->flip_count);
+					work->flip_count);
 }
 
 static bool
@@ -10976,13 +10980,19 @@ void intel_finish_page_flip_cs(struct drm_i915_private *dev_priv, int pipe)
 	 * lost pageflips) so needs the full irqsave spinlocks.
 	 */
 	spin_lock_irqsave(&dev->event_lock, flags);
-	work = intel_crtc->flip_work;
+	while (!list_empty(&intel_crtc->flip_work)) {
+		work = list_first_entry(&intel_crtc->flip_work,
+					struct intel_flip_work,
+					head);
 
-	if (work != NULL &&
-	    !is_mmio_work(work) &&
-	    pageflip_finished(intel_crtc, work))
-		page_flip_completed(intel_crtc);
+		if (is_mmio_work(work))
+			break;
 
+		if (!pageflip_finished(intel_crtc, work))
+			break;
+
+		page_flip_completed(intel_crtc, work);
+	}
 	spin_unlock_irqrestore(&dev->event_lock, flags);
 }
 
@@ -11003,13 +11013,19 @@ void intel_finish_page_flip_mmio(struct drm_i915_private *dev_priv, int pipe)
 	 * lost pageflips) so needs the full irqsave spinlocks.
 	 */
 	spin_lock_irqsave(&dev->event_lock, flags);
-	work = intel_crtc->flip_work;
+	while (!list_empty(&intel_crtc->flip_work)) {
+		work = list_first_entry(&intel_crtc->flip_work,
+					struct intel_flip_work,
+					head);
 
-	if (work != NULL &&
-	    is_mmio_work(work) &&
-	    pageflip_finished(intel_crtc, work))
-		page_flip_completed(intel_crtc);
+		if (!is_mmio_work(work))
+			break;
+
+		if (!pageflip_finished(intel_crtc, work))
+			break;
 
+		page_flip_completed(intel_crtc, work);
+	}
 	spin_unlock_irqrestore(&dev->event_lock, flags);
 }
 
@@ -11028,7 +11044,7 @@ static int intel_gen2_queue_flip(struct drm_device *dev,
 				 struct drm_framebuffer *fb,
 				 struct drm_i915_gem_object *obj,
 				 struct drm_i915_gem_request *req,
-				 uint32_t flags)
+				 uint64_t gtt_offset)
 {
 	struct intel_engine_cs *engine = req->engine;
 	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
@@ -11051,7 +11067,7 @@ static int intel_gen2_queue_flip(struct drm_device *dev,
 	intel_ring_emit(engine, MI_DISPLAY_FLIP |
 			MI_DISPLAY_FLIP_PLANE(intel_crtc->plane));
 	intel_ring_emit(engine, fb->pitches[0]);
-	intel_ring_emit(engine, intel_crtc->flip_work->gtt_offset);
+	intel_ring_emit(engine, gtt_offset);
 	intel_ring_emit(engine, 0); /* aux display base address, unused */
 
 	return 0;
@@ -11062,7 +11078,7 @@ static int intel_gen3_queue_flip(struct drm_device *dev,
 				 struct drm_framebuffer *fb,
 				 struct drm_i915_gem_object *obj,
 				 struct drm_i915_gem_request *req,
-				 uint32_t flags)
+				 uint64_t gtt_offset)
 {
 	struct intel_engine_cs *engine = req->engine;
 	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
@@ -11082,7 +11098,7 @@ static int intel_gen3_queue_flip(struct drm_device *dev,
 	intel_ring_emit(engine, MI_DISPLAY_FLIP_I915 |
 			MI_DISPLAY_FLIP_PLANE(intel_crtc->plane));
 	intel_ring_emit(engine, fb->pitches[0]);
-	intel_ring_emit(engine, intel_crtc->flip_work->gtt_offset);
+	intel_ring_emit(engine, gtt_offset);
 	intel_ring_emit(engine, MI_NOOP);
 
 	return 0;
@@ -11093,7 +11109,7 @@ static int intel_gen4_queue_flip(struct drm_device *dev,
 				 struct drm_framebuffer *fb,
 				 struct drm_i915_gem_object *obj,
 				 struct drm_i915_gem_request *req,
-				 uint32_t flags)
+				 uint64_t gtt_offset)
 {
 	struct intel_engine_cs *engine = req->engine;
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -11112,8 +11128,7 @@ static int intel_gen4_queue_flip(struct drm_device *dev,
 	intel_ring_emit(engine, MI_DISPLAY_FLIP |
 			MI_DISPLAY_FLIP_PLANE(intel_crtc->plane));
 	intel_ring_emit(engine, fb->pitches[0]);
-	intel_ring_emit(engine, intel_crtc->flip_work->gtt_offset |
-			obj->tiling_mode);
+	intel_ring_emit(engine, gtt_offset | obj->tiling_mode);
 
 	/* XXX Enabling the panel-fitter across page-flip is so far
 	 * untested on non-native modes, so ignore it for now.
@@ -11131,7 +11146,7 @@ static int intel_gen6_queue_flip(struct drm_device *dev,
 				 struct drm_framebuffer *fb,
 				 struct drm_i915_gem_object *obj,
 				 struct drm_i915_gem_request *req,
-				 uint32_t flags)
+				 uint64_t gtt_offset)
 {
 	struct intel_engine_cs *engine = req->engine;
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -11146,7 +11161,7 @@ static int intel_gen6_queue_flip(struct drm_device *dev,
 	intel_ring_emit(engine, MI_DISPLAY_FLIP |
 			MI_DISPLAY_FLIP_PLANE(intel_crtc->plane));
 	intel_ring_emit(engine, fb->pitches[0] | obj->tiling_mode);
-	intel_ring_emit(engine, intel_crtc->flip_work->gtt_offset);
+	intel_ring_emit(engine, gtt_offset);
 
 	/* Contrary to the suggestions in the documentation,
 	 * "Enable Panel Fitter" does not seem to be required when page
@@ -11166,7 +11181,7 @@ static int intel_gen7_queue_flip(struct drm_device *dev,
 				 struct drm_framebuffer *fb,
 				 struct drm_i915_gem_object *obj,
 				 struct drm_i915_gem_request *req,
-				 uint32_t flags)
+				 uint64_t gtt_offset)
 {
 	struct intel_engine_cs *engine = req->engine;
 	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
@@ -11249,7 +11264,7 @@ static int intel_gen7_queue_flip(struct drm_device *dev,
 
 	intel_ring_emit(engine, MI_DISPLAY_FLIP_I915 | plane_bit);
 	intel_ring_emit(engine, (fb->pitches[0] | obj->tiling_mode));
-	intel_ring_emit(engine, intel_crtc->flip_work->gtt_offset);
+	intel_ring_emit(engine, gtt_offset);
 	intel_ring_emit(engine, (MI_NOOP));
 
 	return 0;
@@ -11316,7 +11331,7 @@ static int intel_default_queue_flip(struct drm_device *dev,
 				    struct drm_framebuffer *fb,
 				    struct drm_i915_gem_object *obj,
 				    struct drm_i915_gem_request *req,
-				    uint32_t flags)
+				    uint64_t gtt_offset)
 {
 	return -ENODEV;
 }
@@ -11371,20 +11386,26 @@ void intel_check_page_flip(struct drm_i915_private *dev_priv, int pipe)
 		return;
 
 	spin_lock(&dev->event_lock);
-	work = intel_crtc->flip_work;
+	while (!list_empty(&intel_crtc->flip_work)) {
+		work = list_first_entry(&intel_crtc->flip_work,
+					struct intel_flip_work, head);
+
+		if (is_mmio_work(work))
+			break;
 
-	if (work != NULL && !is_mmio_work(work) &&
-	    __pageflip_stall_check_cs(dev_priv, intel_crtc, work)) {
+		if (__pageflip_stall_check_cs(dev_priv, intel_crtc, work)) {
 			WARN_ONCE(1,
 				  "Kicking stuck page flip: queued at %d, now %d\n",
 				work->flip_queued_vblank, intel_crtc_get_vblank_counter(intel_crtc));
-		page_flip_completed(intel_crtc);
-		work = NULL;
+			page_flip_completed(intel_crtc, work);
+			continue;
 		}
 
-	if (work != NULL && !is_mmio_work(work) &&
-	    intel_crtc_get_vblank_counter(intel_crtc) - work->flip_queued_vblank > 1)
+		if (intel_crtc_get_vblank_counter(intel_crtc) - work->flip_queued_vblank > 1)
 			intel_queue_rps_boost_for_request(work->flip_queued_req);
+
+		break;
+	}
 	spin_unlock(&dev->event_lock);
 }
 
@@ -11445,13 +11466,18 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
 
 	/* We borrow the event spin lock for protecting flip_work */
 	spin_lock_irq(&dev->event_lock);
-	if (intel_crtc->flip_work) {
+	if (!list_empty(&intel_crtc->flip_work)) {
+		struct intel_flip_work *old_work;
+
+		old_work = list_last_entry(&intel_crtc->flip_work,
+					   struct intel_flip_work, head);
+
 		/* Before declaring the flip queue wedged, check if
 		 * the hardware completed the operation behind our backs.
 		 */
-		if (pageflip_finished(intel_crtc, intel_crtc->flip_work)) {
+		if (pageflip_finished(intel_crtc, old_work)) {
 			DRM_DEBUG_DRIVER("flip queue: previous flip completed, continuing\n");
-			page_flip_completed(intel_crtc);
+			page_flip_completed(intel_crtc, old_work);
 		} else {
 			DRM_DEBUG_DRIVER("flip queue: crtc already busy\n");
 			spin_unlock_irq(&dev->event_lock);
@@ -11461,7 +11487,7 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
 			return -EBUSY;
 		}
 	}
-	intel_crtc->flip_work = work;
+	list_add_tail(&work->head, &intel_crtc->flip_work);
 	spin_unlock_irq(&dev->event_lock);
 
 	if (atomic_read(&intel_crtc->unpin_work_count) >= 2)
@@ -11543,7 +11569,7 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
 	} else {
 		i915_gem_request_assign(&work->flip_queued_req, request);
 		ret = dev_priv->display.queue_flip(dev, crtc, fb, obj, request,
-						   page_flip_flags);
+						   work->gtt_offset);
 		if (ret)
 			goto cleanup_unpin;
 
@@ -11578,7 +11604,7 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
 	drm_framebuffer_unreference(work->old_fb);
 
 	spin_lock_irq(&dev->event_lock);
-	intel_crtc->flip_work = NULL;
+	list_del(&work->head);
 	spin_unlock_irq(&dev->event_lock);
 
 	drm_crtc_vblank_put(crtc);
@@ -14184,6 +14210,8 @@ static void intel_crtc_init(struct drm_device *dev, int pipe)
 	intel_crtc->base.state = &crtc_state->base;
 	crtc_state->base.crtc = &intel_crtc->base;
 
+	INIT_LIST_HEAD(&intel_crtc->flip_work);
+
 	/* initialize shared scalers */
 	if (INTEL_INFO(dev)->gen >= 9) {
 		if (pipe == PIPE_C)

drivers/gpu/drm/i915/intel_drv.h

@@ -641,7 +641,7 @@ struct intel_crtc {
 	unsigned long enabled_power_domains;
 	bool lowfreq_avail;
 	struct intel_overlay *overlay;
-	struct intel_flip_work *flip_work;
+	struct list_head flip_work;
 
 	atomic_t unpin_work_count;
 
@@ -970,6 +970,8 @@ intel_get_crtc_for_plane(struct drm_device *dev, int plane)
 }
 
 struct intel_flip_work {
+	struct list_head head;
+
 	struct work_struct unpin_work;
 	struct work_struct mmio_work;