drm/i915: Extract intel_frontbuffer active tracking

Move the active tracking for the frontbuffer operations out of the
i915_gem_object and into its own first class (refcounted) object. In the
process of detangling, we switch from low level request tracking to the
easier i915_active -- with the plan that this avoids any potential
atomic callbacks as the frontbuffer tracking wishes to sleep as it
flushes.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190816074635.26062-1-chris@chris-wilson.co.uk

Documentation/gpu/i915.rst

@@ -91,9 +91,6 @@ Frontbuffer Tracking
 .. kernel-doc:: drivers/gpu/drm/i915/display/intel_frontbuffer.c
    :internal:
 
-.. kernel-doc:: drivers/gpu/drm/i915/i915_gem.c
-   :functions: i915_gem_track_fb
-
 Display FIFO Underrun Reporting
 -------------------------------
 

drivers/gpu/drm/i915/display/intel_display.c

@@ -3049,12 +3049,13 @@ intel_alloc_initial_plane_obj(struct intel_crtc *crtc,
 {
 	struct drm_device *dev = crtc->base.dev;
 	struct drm_i915_private *dev_priv = to_i915(dev);
-	struct drm_i915_gem_object *obj = NULL;
 	struct drm_mode_fb_cmd2 mode_cmd = { 0 };
 	struct drm_framebuffer *fb = &plane_config->fb->base;
 	u32 base_aligned = round_down(plane_config->base, PAGE_SIZE);
 	u32 size_aligned = round_up(plane_config->base + plane_config->size,
 				    PAGE_SIZE);
+	struct drm_i915_gem_object *obj;
+	bool ret = false;
 
 	size_aligned -= base_aligned;
 
@@ -3096,7 +3097,7 @@ intel_alloc_initial_plane_obj(struct intel_crtc *crtc,
 		break;
 	default:
 		MISSING_CASE(plane_config->tiling);
-		return false;
+		goto out;
 	}
 
 	mode_cmd.pixel_format = fb->format->format;
@@ -3108,16 +3109,15 @@ intel_alloc_initial_plane_obj(struct intel_crtc *crtc,
 
 	if (intel_framebuffer_init(to_intel_framebuffer(fb), obj, &mode_cmd)) {
 		DRM_DEBUG_KMS("intel fb init failed\n");
-		goto out_unref_obj;
+		goto out;
 	}
 
 
 	DRM_DEBUG_KMS("initial plane fb obj %p\n", obj);
-	return true;
-
-out_unref_obj:
+	ret = true;
+out:
 	i915_gem_object_put(obj);
-	return false;
+	return ret;
 }
 
 static void
@@ -3174,14 +3174,19 @@ static void intel_plane_disable_noatomic(struct intel_crtc *crtc,
 	intel_disable_plane(plane, crtc_state);
 }
 
+static struct intel_frontbuffer *
+to_intel_frontbuffer(struct drm_framebuffer *fb)
+{
+	return fb ? to_intel_framebuffer(fb)->frontbuffer : NULL;
+}
+
 static void
 intel_find_initial_plane_obj(struct intel_crtc *intel_crtc,
 			     struct intel_initial_plane_config *plane_config)
 {
 	struct drm_device *dev = intel_crtc->base.dev;
 	struct drm_i915_private *dev_priv = to_i915(dev);
 	struct drm_crtc *c;
-	struct drm_i915_gem_object *obj;
 	struct drm_plane *primary = intel_crtc->base.primary;
 	struct drm_plane_state *plane_state = primary->state;
 	struct intel_plane *intel_plane = to_intel_plane(primary);
@@ -3257,8 +3262,7 @@ intel_find_initial_plane_obj(struct intel_crtc *intel_crtc,
 		return;
 	}
 
-	obj = intel_fb_obj(fb);
-	intel_fb_obj_flush(obj, ORIGIN_DIRTYFB);
+	intel_frontbuffer_flush(to_intel_frontbuffer(fb), ORIGIN_DIRTYFB);
 
 	plane_state->src_x = 0;
 	plane_state->src_y = 0;
@@ -3273,14 +3277,14 @@ intel_find_initial_plane_obj(struct intel_crtc *intel_crtc,
 	intel_state->base.src = drm_plane_state_src(plane_state);
 	intel_state->base.dst = drm_plane_state_dest(plane_state);
 
-	if (i915_gem_object_is_tiled(obj))
+	if (plane_config->tiling)
 		dev_priv->preserve_bios_swizzle = true;
 
 	plane_state->fb = fb;
 	plane_state->crtc = &intel_crtc->base;
 
 	atomic_or(to_intel_plane(primary)->frontbuffer_bit,
-		  &obj->frontbuffer_bits);
+		  &to_intel_frontbuffer(fb)->bits);
 }
 
 static int skl_max_plane_width(const struct drm_framebuffer *fb,
@@ -14132,9 +14136,9 @@ static void intel_atomic_track_fbs(struct intel_atomic_state *state)
 
 	for_each_oldnew_intel_plane_in_state(state, plane, old_plane_state,
 					     new_plane_state, i)
-		i915_gem_track_fb(intel_fb_obj(old_plane_state->base.fb),
-				  intel_fb_obj(new_plane_state->base.fb),
-				  plane->frontbuffer_bit);
+		intel_frontbuffer_track(to_intel_frontbuffer(old_plane_state->base.fb),
+					to_intel_frontbuffer(new_plane_state->base.fb),
+					plane->frontbuffer_bit);
 }
 
 static int intel_atomic_commit(struct drm_device *dev,
@@ -14418,7 +14422,7 @@ intel_prepare_plane_fb(struct drm_plane *plane,
 		return ret;
 
 	fb_obj_bump_render_priority(obj);
-	intel_fb_obj_flush(obj, ORIGIN_DIRTYFB);
+	intel_frontbuffer_flush(obj->frontbuffer, ORIGIN_DIRTYFB);
 
 	if (!new_state->fence) { /* implicit fencing */
 		struct dma_fence *fence;
@@ -14681,13 +14685,12 @@ intel_legacy_cursor_update(struct drm_plane *plane,
 			   struct drm_modeset_acquire_ctx *ctx)
 {
 	struct drm_i915_private *dev_priv = to_i915(crtc->dev);
-	int ret;
 	struct drm_plane_state *old_plane_state, *new_plane_state;
 	struct intel_plane *intel_plane = to_intel_plane(plane);
-	struct drm_framebuffer *old_fb;
 	struct intel_crtc_state *crtc_state =
 		to_intel_crtc_state(crtc->state);
 	struct intel_crtc_state *new_crtc_state;
+	int ret;
 
 	/*
 	 * When crtc is inactive or there is a modeset pending,
@@ -14755,11 +14758,10 @@ intel_legacy_cursor_update(struct drm_plane *plane,
 	if (ret)
 		goto out_unlock;
 
-	intel_fb_obj_flush(intel_fb_obj(fb), ORIGIN_FLIP);
-
-	old_fb = old_plane_state->fb;
-	i915_gem_track_fb(intel_fb_obj(old_fb), intel_fb_obj(fb),
-			  intel_plane->frontbuffer_bit);
+	intel_frontbuffer_flush(to_intel_frontbuffer(fb), ORIGIN_FLIP);
+	intel_frontbuffer_track(to_intel_frontbuffer(old_plane_state->fb),
+				to_intel_frontbuffer(fb),
+				intel_plane->frontbuffer_bit);
 
 	/* Swap plane state */
 	plane->state = new_plane_state;
@@ -15540,15 +15542,9 @@ static void intel_setup_outputs(struct drm_i915_private *dev_priv)
 static void intel_user_framebuffer_destroy(struct drm_framebuffer *fb)
 {
 	struct intel_framebuffer *intel_fb = to_intel_framebuffer(fb);
-	struct drm_i915_gem_object *obj = intel_fb_obj(fb);
 
 	drm_framebuffer_cleanup(fb);
-
-	i915_gem_object_lock(obj);
-	WARN_ON(!obj->framebuffer_references--);
-	i915_gem_object_unlock(obj);
-
-	i915_gem_object_put(obj);
+	intel_frontbuffer_put(intel_fb->frontbuffer);
 
 	kfree(intel_fb);
 }
@@ -15576,7 +15572,7 @@ static int intel_user_framebuffer_dirty(struct drm_framebuffer *fb,
 	struct drm_i915_gem_object *obj = intel_fb_obj(fb);
 
 	i915_gem_object_flush_if_display(obj);
-	intel_fb_obj_flush(obj, ORIGIN_DIRTYFB);
+	intel_frontbuffer_flush(to_intel_frontbuffer(fb), ORIGIN_DIRTYFB);
 
 	return 0;
 }
@@ -15598,8 +15594,11 @@ static int intel_framebuffer_init(struct intel_framebuffer *intel_fb,
 	int ret = -EINVAL;
 	int i;
 
+	intel_fb->frontbuffer = intel_frontbuffer_get(obj);
+	if (!intel_fb->frontbuffer)
+		return -ENOMEM;
+
 	i915_gem_object_lock(obj);
-	obj->framebuffer_references++;
 	tiling = i915_gem_object_get_tiling(obj);
 	stride = i915_gem_object_get_stride(obj);
 	i915_gem_object_unlock(obj);
@@ -15716,9 +15715,7 @@ static int intel_framebuffer_init(struct intel_framebuffer *intel_fb,
 	return 0;
 
 err:
-	i915_gem_object_lock(obj);
-	obj->framebuffer_references--;
-	i915_gem_object_unlock(obj);
+	intel_frontbuffer_put(intel_fb->frontbuffer);
 	return ret;
 }
 
@@ -15736,8 +15733,7 @@ intel_user_framebuffer_create(struct drm_device *dev,
 		return ERR_PTR(-ENOENT);
 
 	fb = intel_framebuffer_create(obj, &mode_cmd);
-	if (IS_ERR(fb))
-		i915_gem_object_put(obj);
+	i915_gem_object_put(obj);
 
 	return fb;
 }

drivers/gpu/drm/i915/display/intel_display_types.h

@@ -84,6 +84,7 @@ enum intel_broadcast_rgb {
 
 struct intel_framebuffer {
 	struct drm_framebuffer base;
+	struct intel_frontbuffer *frontbuffer;
 	struct intel_rotation_info rot_info;
 
 	/* for each plane in the normal GTT view */

drivers/gpu/drm/i915/display/intel_fbdev.c

@@ -47,13 +47,14 @@
 #include "intel_fbdev.h"
 #include "intel_frontbuffer.h"
 
-static void intel_fbdev_invalidate(struct intel_fbdev *ifbdev)
+static struct intel_frontbuffer *to_frontbuffer(struct intel_fbdev *ifbdev)
 {
-	struct drm_i915_gem_object *obj = intel_fb_obj(&ifbdev->fb->base);
-	unsigned int origin =
-		ifbdev->vma_flags & PLANE_HAS_FENCE ? ORIGIN_GTT : ORIGIN_CPU;
+	return ifbdev->fb->frontbuffer;
+}
 
-	intel_fb_obj_invalidate(obj, origin);
+static void intel_fbdev_invalidate(struct intel_fbdev *ifbdev)
+{
+	intel_frontbuffer_invalidate(to_frontbuffer(ifbdev), ORIGIN_CPU);
 }
 
 static int intel_fbdev_set_par(struct fb_info *info)
@@ -120,7 +121,7 @@ static int intelfb_alloc(struct drm_fb_helper *helper,
 	struct drm_i915_private *dev_priv = to_i915(dev);
 	struct drm_mode_fb_cmd2 mode_cmd = {};
 	struct drm_i915_gem_object *obj;
-	int size, ret;
+	int size;
 
 	/* we don't do packed 24bpp */
 	if (sizes->surface_bpp == 24)
@@ -147,24 +148,16 @@ static int intelfb_alloc(struct drm_fb_helper *helper,
 		obj = i915_gem_object_create_shmem(dev_priv, size);
 	if (IS_ERR(obj)) {
 		DRM_ERROR("failed to allocate framebuffer\n");
-		ret = PTR_ERR(obj);
-		goto err;
+		return PTR_ERR(obj);
 	}
 
 	fb = intel_framebuffer_create(obj, &mode_cmd);
-	if (IS_ERR(fb)) {
-		ret = PTR_ERR(fb);
-		goto err_obj;
-	}
+	i915_gem_object_put(obj);
+	if (IS_ERR(fb))
+		return PTR_ERR(fb);
 
 	ifbdev->fb = to_intel_framebuffer(fb);
-
 	return 0;
-
-err_obj:
-	i915_gem_object_put(obj);
-err:
-	return ret;
 }
 
 static int intelfb_create(struct drm_fb_helper *helper,
@@ -180,7 +173,6 @@ static int intelfb_create(struct drm_fb_helper *helper,
 	const struct i915_ggtt_view view = {
 		.type = I915_GGTT_VIEW_NORMAL,
 	};
-	struct drm_framebuffer *fb;
 	intel_wakeref_t wakeref;
 	struct fb_info *info;
 	struct i915_vma *vma;
@@ -226,8 +218,7 @@ static int intelfb_create(struct drm_fb_helper *helper,
 		goto out_unlock;
 	}
 
-	fb = &ifbdev->fb->base;
-	intel_fb_obj_flush(intel_fb_obj(fb), ORIGIN_DIRTYFB);
+	intel_frontbuffer_flush(to_frontbuffer(ifbdev), ORIGIN_DIRTYFB);
 
 	info = drm_fb_helper_alloc_fbi(helper);
 	if (IS_ERR(info)) {
@@ -236,7 +227,7 @@ static int intelfb_create(struct drm_fb_helper *helper,
 		goto out_unpin;
 	}
 
-	ifbdev->helper.fb = fb;
+	ifbdev->helper.fb = &ifbdev->fb->base;
 
 	info->fbops = &intelfb_ops;
 
@@ -263,13 +254,14 @@ static int intelfb_create(struct drm_fb_helper *helper,
 	 * If the object is stolen however, it will be full of whatever
 	 * garbage was left in there.
 	 */
-	if (intel_fb_obj(fb)->stolen && !prealloc)
+	if (vma->obj->stolen && !prealloc)
 		memset_io(info->screen_base, 0, info->screen_size);
 
 	/* Use default scratch pixmap (info->pixmap.flags = FB_PIXMAP_SYSTEM) */
 
 	DRM_DEBUG_KMS("allocated %dx%d fb: 0x%08x\n",
-		      fb->width, fb->height, i915_ggtt_offset(vma));
+		      ifbdev->fb->base.width, ifbdev->fb->base.height,
+		      i915_ggtt_offset(vma));
 	ifbdev->vma = vma;
 	ifbdev->vma_flags = flags;