drm/i915: Add intel implementation of the pageflip ioctl

Acked-by: Jakob Bornecrantz <jakob@vmware.com>
Acked-by: Thomas Hellström <thomas@shipmail.org>
Review-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Jesse "Orange Smoothie" Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Kristian Høgsberg <krh@bitplanet.net>
Signed-off-by: Eric Anholt <eric@anholt.net>

drivers/gpu/drm/i915/i915_drv.h

@@ -536,6 +536,10 @@ typedef struct drm_i915_private {
 	/* indicate whether the LVDS_BORDER should be enabled or not */
 	unsigned int lvds_border_bits;
 
+	struct drm_crtc *plane_to_crtc_mapping[2];
+	struct drm_crtc *pipe_to_crtc_mapping[2];
+	wait_queue_head_t pending_flip_queue;
+
 	/* Reclocking support */
 	bool render_reclock_avail;
 	bool lvds_downclock_avail;
@@ -639,6 +643,13 @@ struct drm_i915_gem_object {
 	 * Advice: are the backing pages purgeable?
 	 */
 	int madv;
+
+	/**
+	 * Number of crtcs where this object is currently the fb, but
+	 * will be page flipped away on the next vblank.  When it
+	 * reaches 0, dev_priv->pending_flip_queue will be woken up.
+	 */
+	atomic_t pending_flip;
 };
 
 /**
@@ -830,6 +841,7 @@ void i915_gem_free_all_phys_object(struct drm_device *dev);
 int i915_gem_object_get_pages(struct drm_gem_object *obj);
 void i915_gem_object_put_pages(struct drm_gem_object *obj);
 void i915_gem_release(struct drm_device * dev, struct drm_file *file_priv);
+void i915_gem_object_flush_write_domain(struct drm_gem_object *obj);
 
 void i915_gem_shrinker_init(void);
 void i915_gem_shrinker_exit(void);

drivers/gpu/drm/i915/i915_gem.c

@@ -2771,6 +2771,22 @@ i915_gem_object_flush_cpu_write_domain(struct drm_gem_object *obj)
 					    old_write_domain);
 }
 
+void
+i915_gem_object_flush_write_domain(struct drm_gem_object *obj)
+{
+	switch (obj->write_domain) {
+	case I915_GEM_DOMAIN_GTT:
+		i915_gem_object_flush_gtt_write_domain(obj);
+		break;
+	case I915_GEM_DOMAIN_CPU:
+		i915_gem_object_flush_cpu_write_domain(obj);
+		break;
+	default:
+		i915_gem_object_flush_gpu_write_domain(obj);
+		break;
+	}
+}
+
 /**
  * Moves a single object to the GTT read, and possibly write domain.
  *
@@ -3536,6 +3552,41 @@ i915_gem_check_execbuffer (struct drm_i915_gem_execbuffer *exec,
 	return 0;
 }
 
+static int
+i915_gem_wait_for_pending_flip(struct drm_device *dev,
+			       struct drm_gem_object **object_list,
+			       int count)
+{
+	drm_i915_private_t *dev_priv = dev->dev_private;
+	struct drm_i915_gem_object *obj_priv;
+	DEFINE_WAIT(wait);
+	int i, ret = 0;
+
+	for (;;) {
+		prepare_to_wait(&dev_priv->pending_flip_queue,
+				&wait, TASK_INTERRUPTIBLE);
+		for (i = 0; i < count; i++) {
+			obj_priv = object_list[i]->driver_private;
+			if (atomic_read(&obj_priv->pending_flip) > 0)
+				break;
+		}
+		if (i == count)
+			break;
+
+		if (!signal_pending(current)) {
+			mutex_unlock(&dev->struct_mutex);
+			schedule();
+			mutex_lock(&dev->struct_mutex);
+			continue;
+		}
+		ret = -ERESTARTSYS;
+		break;
+	}
+	finish_wait(&dev_priv->pending_flip_queue, &wait);
+
+	return ret;
+}
+
 int
 i915_gem_execbuffer(struct drm_device *dev, void *data,
 		    struct drm_file *file_priv)
@@ -3551,7 +3602,7 @@ i915_gem_execbuffer(struct drm_device *dev, void *data,
 	int ret, ret2, i, pinned = 0;
 	uint64_t exec_offset;
 	uint32_t seqno, flush_domains, reloc_index;
-	int pin_tries;
+	int pin_tries, flips;
 
 #if WATCH_EXEC
 	DRM_INFO("buffers_ptr %d buffer_count %d len %08x\n",
@@ -3623,6 +3674,7 @@ i915_gem_execbuffer(struct drm_device *dev, void *data,
 	}
 
 	/* Look up object handles */
+	flips = 0;
 	for (i = 0; i < args->buffer_count; i++) {
 		object_list[i] = drm_gem_object_lookup(dev, file_priv,
 						       exec_list[i].handle);
@@ -3641,6 +3693,14 @@ i915_gem_execbuffer(struct drm_device *dev, void *data,
 			goto err;
 		}
 		obj_priv->in_execbuffer = true;
+		flips += atomic_read(&obj_priv->pending_flip);
+	}
+
+	if (flips > 0) {
+		ret = i915_gem_wait_for_pending_flip(dev, object_list,
+						     args->buffer_count);
+		if (ret)
+			goto err;
 	}
 
 	/* Pin and relocate */
@@ -4625,8 +4685,8 @@ i915_gem_load(struct drm_device *dev)
 			for (i = 0; i < 8; i++)
 				I915_WRITE(FENCE_REG_945_8 + (i * 4), 0);
 	}
-
 	i915_gem_detect_bit_6_swizzle(dev);
+	init_waitqueue_head(&dev_priv->pending_flip_queue);
 }
 
 /*

drivers/gpu/drm/i915/i915_irq.c

@@ -43,10 +43,13 @@
  * we leave them always unmasked in IMR and then control enabling them through
  * PIPESTAT alone.
  */
-#define I915_INTERRUPT_ENABLE_FIX (I915_ASLE_INTERRUPT |		 \
-				   I915_DISPLAY_PIPE_A_EVENT_INTERRUPT | \
-				   I915_DISPLAY_PIPE_B_EVENT_INTERRUPT | \
-				   I915_RENDER_COMMAND_PARSER_ERROR_INTERRUPT)
+#define I915_INTERRUPT_ENABLE_FIX			\
+	(I915_ASLE_INTERRUPT |				\
+	 I915_DISPLAY_PIPE_A_EVENT_INTERRUPT |		\
+	 I915_DISPLAY_PIPE_B_EVENT_INTERRUPT |		\
+	 I915_DISPLAY_PLANE_A_FLIP_PENDING_INTERRUPT |	\
+	 I915_DISPLAY_PLANE_B_FLIP_PENDING_INTERRUPT |	\
+	 I915_RENDER_COMMAND_PARSER_ERROR_INTERRUPT)
 
 /** Interrupts that we mask and unmask at runtime. */
 #define I915_INTERRUPT_ENABLE_VAR (I915_USER_INTERRUPT)
@@ -643,14 +646,22 @@ irqreturn_t i915_driver_irq_handler(DRM_IRQ_ARGS)
 			mod_timer(&dev_priv->hangcheck_timer, jiffies + DRM_I915_HANGCHECK_PERIOD);
 		}
 
+		if (iir & I915_DISPLAY_PLANE_A_FLIP_PENDING_INTERRUPT)
+			intel_prepare_page_flip(dev, 0);
+
+		if (iir & I915_DISPLAY_PLANE_B_FLIP_PENDING_INTERRUPT)
+			intel_prepare_page_flip(dev, 1);
+
 		if (pipea_stats & vblank_status) {
 			vblank++;
 			drm_handle_vblank(dev, 0);
+			intel_finish_page_flip(dev, 0);
 		}
 
 		if (pipeb_stats & vblank_status) {
 			vblank++;
 			drm_handle_vblank(dev, 1);
+			intel_finish_page_flip(dev, 1);
 		}
 
 		if ((pipeb_stats & I915_LEGACY_BLC_EVENT_STATUS) ||

drivers/gpu/drm/i915/i915_reg.h

@@ -157,6 +157,8 @@
 #define   MI_OVERLAY_ON		(0x1<<21)
 #define   MI_OVERLAY_OFF	(0x2<<21)
 #define MI_LOAD_SCAN_LINES_INCL MI_INSTR(0x12, 0)
+#define MI_DISPLAY_FLIP		MI_INSTR(0x14, 2)
+#define   MI_DISPLAY_FLIP_PLANE(n) ((n) << 20)
 #define MI_STORE_DWORD_IMM	MI_INSTR(0x20, 1)
 #define   MI_MEM_VIRTUAL	(1 << 22) /* 965+ only */
 #define MI_STORE_DWORD_INDEX	MI_INSTR(0x21, 1)