drm: pin new and unpin old buffer when setting a mode.

This removes the requirement for user space to pin a buffer before
setting a mode that is backed by the pixels from that buffer.
Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@linux.ie>

drivers/gpu/drm/drm_crtc_helper.c

@@ -432,7 +432,8 @@ static void drm_setup_crtcs(struct drm_device *dev)
  */
 bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
 			      struct drm_display_mode *mode,
-			      int x, int y)
+			      int x, int y,
+			      struct drm_framebuffer *old_fb)
 {
 	struct drm_device *dev = crtc->dev;
 	struct drm_display_mode *adjusted_mode, saved_mode;
@@ -462,7 +463,8 @@ bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
 
 	if (drm_mode_equal(&saved_mode, &crtc->mode)) {
 		if (saved_x != crtc->x || saved_y != crtc->y) {
-			crtc_funcs->mode_set_base(crtc, crtc->x, crtc->y);
+			crtc_funcs->mode_set_base(crtc, crtc->x, crtc->y,
+						  old_fb);
 			goto done;
 		}
 	}
@@ -501,7 +503,7 @@ bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
 	/* Set up the DPLL and any encoders state that needs to adjust or depend
 	 * on the DPLL.
 	 */
-	crtc_funcs->mode_set(crtc, mode, adjusted_mode, x, y);
+	crtc_funcs->mode_set(crtc, mode, adjusted_mode, x, y, old_fb);
 
 	list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 
@@ -564,6 +566,7 @@ int drm_crtc_helper_set_config(struct drm_mode_set *set)
 	struct drm_device *dev;
 	struct drm_crtc **save_crtcs, *new_crtc;
 	struct drm_encoder **save_encoders, *new_encoder;
+	struct drm_framebuffer *old_fb;
 	bool save_enabled;
 	bool changed = false;
 	bool flip_or_move = false;
@@ -684,13 +687,15 @@ int drm_crtc_helper_set_config(struct drm_mode_set *set)
 		changed = true;
 
 	if (changed) {
+		old_fb = set->crtc->fb;
 		set->crtc->fb = set->fb;
 		set->crtc->enabled = (set->mode != NULL);
 		if (set->mode != NULL) {
 			DRM_DEBUG("attempting to set mode from userspace\n");
 			drm_mode_debug_printmodeline(set->mode);
 			if (!drm_crtc_helper_set_mode(set->crtc, set->mode,
-						      set->x, set->y)) {
+						      set->x, set->y,
+						      old_fb)) {
 				ret = -EINVAL;
 				goto fail_set_mode;
 			}
@@ -701,9 +706,10 @@ int drm_crtc_helper_set_config(struct drm_mode_set *set)
 		}
 		drm_helper_disable_unused_functions(dev);
 	} else if (flip_or_move) {
+		old_fb = set->crtc->fb;
 		if (set->crtc->fb != set->fb)
 			set->crtc->fb = set->fb;
-		crtc_funcs->mode_set_base(set->crtc, set->x, set->y);
+		crtc_funcs->mode_set_base(set->crtc, set->x, set->y, old_fb);
 	}
 
 	kfree(save_encoders);
@@ -809,8 +815,8 @@ int drm_helper_resume_force_mode(struct drm_device *dev)
 		if (!crtc->enabled)
 			continue;
 
-		ret = drm_crtc_helper_set_mode(crtc, &crtc->mode, crtc->x,
-					       crtc->y);
+		ret = drm_crtc_helper_set_mode(crtc, &crtc->mode,
+					       crtc->x, crtc->y, crtc->fb);
 
 		if (ret == false)
 			DRM_ERROR("failed to set mode on crtc %p\n", crtc);

drivers/gpu/drm/i915/intel_display.c

@@ -344,7 +344,8 @@ intel_wait_for_vblank(struct drm_device *dev)
 }
 
 static void
-intel_pipe_set_base(struct drm_crtc *crtc, int x, int y)
+intel_pipe_set_base(struct drm_crtc *crtc, int x, int y,
+		    struct drm_framebuffer *old_fb)
 {
 	struct drm_device *dev = crtc->dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -359,7 +360,7 @@ intel_pipe_set_base(struct drm_crtc *crtc, int x, int y)
 	int dspsurf = (pipe == 0 ? DSPASURF : DSPBSURF);
 	int dspstride = (pipe == 0) ? DSPASTRIDE : DSPBSTRIDE;
 	int dspcntr_reg = (pipe == 0) ? DSPACNTR : DSPBCNTR;
-	u32 dspcntr;
+	u32 dspcntr, alignment;
 
 	/* no fb bound */
 	if (!crtc->fb) {
@@ -368,10 +369,32 @@ intel_pipe_set_base(struct drm_crtc *crtc, int x, int y)
 	}
 
 	intel_fb = to_intel_framebuffer(crtc->fb);
-
 	obj = intel_fb->obj;
 	obj_priv = obj->driver_private;
 
+	switch (obj_priv->tiling_mode) {
+	case I915_TILING_NONE:
+		alignment = 64 * 1024;
+		break;
+	case I915_TILING_X:
+		if (IS_I9XX(dev))
+			alignment = 1024 * 1024;
+		else
+			alignment = 512 * 1024;
+		break;
+	case I915_TILING_Y:
+		/* FIXME: Is this true? */
+		DRM_ERROR("Y tiled not allowed for scan out buffers\n");
+		return;
+	default:
+		BUG();
+	}
+
+	if (i915_gem_object_pin(intel_fb->obj, alignment))
+		return;
+
+	i915_gem_object_set_to_gtt_domain(intel_fb->obj, 1);
+
 	Start = obj_priv->gtt_offset;
 	Offset = y * crtc->fb->pitch + x * (crtc->fb->bits_per_pixel / 8);
 
@@ -409,6 +432,12 @@ intel_pipe_set_base(struct drm_crtc *crtc, int x, int y)
 		I915_READ(dspbase);
 	}
 
+	intel_wait_for_vblank(dev);
+
+	if (old_fb) {
+		intel_fb = to_intel_framebuffer(old_fb);
+		i915_gem_object_unpin(intel_fb->obj);
+	}
 
 	if (!dev->primary->master)
 		return;
@@ -680,7 +709,8 @@ static int intel_panel_fitter_pipe (struct drm_device *dev)
 static void intel_crtc_mode_set(struct drm_crtc *crtc,
 				struct drm_display_mode *mode,
 				struct drm_display_mode *adjusted_mode,
-				int x, int y)
+				int x, int y,
+				struct drm_framebuffer *old_fb)
 {
 	struct drm_device *dev = crtc->dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -915,9 +945,7 @@ static void intel_crtc_mode_set(struct drm_crtc *crtc,
 	I915_WRITE(dspcntr_reg, dspcntr);
 
 	/* Flush the plane changes */
-	intel_pipe_set_base(crtc, x, y);
-
-	intel_wait_for_vblank(dev);
+	intel_pipe_set_base(crtc, x, y, old_fb);
 
 	drm_vblank_post_modeset(dev, pipe);
 }
@@ -1153,7 +1181,7 @@ struct drm_crtc *intel_get_load_detect_pipe(struct intel_output *intel_output,
 	if (!crtc->enabled) {
 		if (!mode)
 			mode = &load_detect_mode;
-		drm_crtc_helper_set_mode(crtc, mode, 0, 0);
+		drm_crtc_helper_set_mode(crtc, mode, 0, 0, crtc->fb);
 	} else {
 		if (intel_crtc->dpms_mode != DRM_MODE_DPMS_ON) {
 			crtc_funcs = crtc->helper_private;

include/drm/drm_crtc_helper.h

@@ -55,10 +55,12 @@ struct drm_crtc_helper_funcs {
 			   struct drm_display_mode *adjusted_mode);
 	/* Actually set the mode */
 	void (*mode_set)(struct drm_crtc *crtc, struct drm_display_mode *mode,
-			 struct drm_display_mode *adjusted_mode, int x, int y);
+			 struct drm_display_mode *adjusted_mode, int x, int y,
+			 struct drm_framebuffer *old_fb);
 
 	/* Move the crtc on the current fb to the given position *optional* */
-	void (*mode_set_base)(struct drm_crtc *crtc, int x, int y);
+	void (*mode_set_base)(struct drm_crtc *crtc, int x, int y,
+			      struct drm_framebuffer *old_fb);
 };
 
 struct drm_encoder_helper_funcs {
@@ -93,7 +95,8 @@ extern bool drm_helper_initial_config(struct drm_device *dev, bool can_grow);
 extern int drm_crtc_helper_set_config(struct drm_mode_set *set);
 extern bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
 				     struct drm_display_mode *mode,
-				     int x, int y);
+				     int x, int y,
+				     struct drm_framebuffer *old_fb);
 extern bool drm_helper_crtc_in_use(struct drm_crtc *crtc);
 
 extern int drm_helper_mode_fill_fb_struct(struct drm_framebuffer *fb,