1 files changed, 135 insertions, 9 deletions

diff --git a/drivers/gpu/drm/i915/intel_fbdev.c b/drivers/gpu/drm/i915/intel_fbdev.c
index 6b5beed28d70..2b1d42dbfe13 100644
--- a/drivers/gpu/drm/i915/intel_fbdev.c
+++ b/drivers/gpu/drm/i915/intel_fbdev.c
@@ -128,6 +128,7 @@ static int intelfb_create(struct drm_fb_helper *helper,
         struct drm_framebuffer *fb;
         struct drm_i915_gem_object *obj;
         int size, ret;
+        bool prealloc = false;
 
         mutex_lock(&dev->struct_mutex);
 
@@ -139,6 +140,7 @@ static int intelfb_create(struct drm_fb_helper *helper,
                 intel_fb = ifbdev->fb;
         } else {
                 DRM_DEBUG_KMS("re-using BIOS fb\n");
+                prealloc = true;
                 sizes->fb_width = intel_fb->base.width;
                 sizes->fb_height = intel_fb->base.height;
         }
@@ -200,7 +202,7 @@ 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 (ifbdev->fb->obj->stolen)
+        if (ifbdev->fb->obj->stolen && !prealloc)
                 memset_io(info->screen_base, 0, info->screen_size);
 
         /* Use default scratch pixmap (info->pixmap.flags = FB_PIXMAP_SYSTEM) */
@@ -454,27 +456,149 @@ static void intel_fbdev_destroy(struct drm_device *dev,
         drm_framebuffer_remove(&ifbdev->fb->base);
 }
 
+/*
+ * Build an intel_fbdev struct using a BIOS allocated framebuffer, if possible.
+ * The core display code will have read out the current plane configuration,
+ * so we use that to figure out if there's an object for us to use as the
+ * fb, and if so, we re-use it for the fbdev configuration.
+ *
+ * Note we only support a single fb shared across pipes for boot (mostly for
+ * fbcon), so we just find the biggest and use that.
+ */
+static bool intel_fbdev_init_bios(struct drm_device *dev,
+                                 struct intel_fbdev *ifbdev)
+{
+        struct intel_framebuffer *fb = NULL;
+        struct drm_crtc *crtc;
+        struct intel_crtc *intel_crtc;
+        struct intel_plane_config *plane_config = NULL;
+        unsigned int max_size = 0;
+
+        if (!i915.fastboot)
+                return false;
+
+        /* Find the largest fb */
+        list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
+                intel_crtc = to_intel_crtc(crtc);
+
+                if (!intel_crtc->active || !crtc->primary->fb) {
+                        DRM_DEBUG_KMS("pipe %c not active or no fb, skipping\n",
+                                      pipe_name(intel_crtc->pipe));
+                        continue;
+                }
+
+                if (intel_crtc->plane_config.size > max_size) {
+                        DRM_DEBUG_KMS("found possible fb from plane %c\n",
+                                      pipe_name(intel_crtc->pipe));
+                        plane_config = &intel_crtc->plane_config;
+                        fb = to_intel_framebuffer(crtc->primary->fb);
+                        max_size = plane_config->size;
+                }
+        }
+
+        if (!fb) {
+                DRM_DEBUG_KMS("no active fbs found, not using BIOS config\n");
+                goto out;
+        }
+
+        /* Now make sure all the pipes will fit into it */
+        list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
+                unsigned int cur_size;
+
+                intel_crtc = to_intel_crtc(crtc);
+
+                if (!intel_crtc->active) {
+                        DRM_DEBUG_KMS("pipe %c not active, skipping\n",
+                                      pipe_name(intel_crtc->pipe));
+                        continue;
+                }
+
+                DRM_DEBUG_KMS("checking plane %c for BIOS fb\n",
+                              pipe_name(intel_crtc->pipe));
+
+                /*
+                 * See if the plane fb we found above will fit on this
+                 * pipe.  Note we need to use the selected fb's bpp rather
+                 * than the current pipe's, since they could be different.
+                 */
+                cur_size = intel_crtc->config.adjusted_mode.crtc_hdisplay *
+                        intel_crtc->config.adjusted_mode.crtc_vdisplay;
+                DRM_DEBUG_KMS("pipe %c area: %d\n", pipe_name(intel_crtc->pipe),
+                              cur_size);
+                cur_size *= fb->base.bits_per_pixel / 8;
+                DRM_DEBUG_KMS("total size %d (bpp %d)\n", cur_size,
+                              fb->base.bits_per_pixel / 8);
+
+                if (cur_size > max_size) {
+                        DRM_DEBUG_KMS("fb not big enough for plane %c (%d vs %d)\n",
+                                      pipe_name(intel_crtc->pipe),
+                                      cur_size, max_size);
+                        plane_config = NULL;
+                        fb = NULL;
+                        break;
+                }
+
+                DRM_DEBUG_KMS("fb big enough for plane %c (%d >= %d)\n",
+                              pipe_name(intel_crtc->pipe),
+                              max_size, cur_size);
+        }
+
+        if (!fb) {
+                DRM_DEBUG_KMS("BIOS fb not suitable for all pipes, not using\n");
+                goto out;
+        }
+
+        ifbdev->preferred_bpp = fb->base.bits_per_pixel;
+        ifbdev->fb = fb;
+
+        drm_framebuffer_reference(&ifbdev->fb->base);
+
+        /* Final pass to check if any active pipes don't have fbs */
+        list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
+                intel_crtc = to_intel_crtc(crtc);
+
+                if (!intel_crtc->active)
+                        continue;
+
+                WARN(!crtc->primary->fb,
+                     "re-used BIOS config but lost an fb on crtc %d\n",
+                     crtc->base.id);
+        }
+
+
+        DRM_DEBUG_KMS("using BIOS fb for initial console\n");
+        return true;
+
+out:
+
+        return false;
+}
+
 int intel_fbdev_init(struct drm_device *dev)
 {
         struct intel_fbdev *ifbdev;
         struct drm_i915_private *dev_priv = dev->dev_private;
         int ret;
 
-        ifbdev = kzalloc(sizeof(*ifbdev), GFP_KERNEL);
-        if (!ifbdev)
+        if (WARN_ON(INTEL_INFO(dev)->num_pipes == 0))
+                return -ENODEV;
+
+        ifbdev = kzalloc(sizeof(struct intel_fbdev), GFP_KERNEL);
+        if (ifbdev == NULL)
                 return -ENOMEM;
 
-        dev_priv->fbdev = ifbdev;
         ifbdev->helper.funcs = &intel_fb_helper_funcs;
+        if (!intel_fbdev_init_bios(dev, ifbdev))
+                ifbdev->preferred_bpp = 32;
 
         ret = drm_fb_helper_init(dev, &ifbdev->helper,
-                                 INTEL_INFO(dev)->num_pipes,
-                                 4);
+                                 INTEL_INFO(dev)->num_pipes, 4);
         if (ret) {
                 kfree(ifbdev);
                 return ret;
         }
 
+        dev_priv->fbdev = ifbdev;
         drm_fb_helper_single_add_all_connectors(&ifbdev->helper);
 
         return 0;
@@ -483,9 +607,10 @@ int intel_fbdev_init(struct drm_device *dev)
 void intel_fbdev_initial_config(struct drm_device *dev)
 {
         struct drm_i915_private *dev_priv = dev->dev_private;
+        struct intel_fbdev *ifbdev = dev_priv->fbdev;
 
         /* Due to peculiar init order wrt to hpd handling this is separate. */
-        drm_fb_helper_initial_config(&dev_priv->fbdev->helper, 32);
+        drm_fb_helper_initial_config(&ifbdev->helper, ifbdev->preferred_bpp);
 }
 
 void intel_fbdev_fini(struct drm_device *dev)
@@ -523,7 +648,8 @@ void intel_fbdev_set_suspend(struct drm_device *dev, int state)
 void intel_fbdev_output_poll_changed(struct drm_device *dev)
 {
         struct drm_i915_private *dev_priv = dev->dev_private;
-        drm_fb_helper_hotplug_event(&dev_priv->fbdev->helper);
+        if (dev_priv->fbdev)
+                drm_fb_helper_hotplug_event(&dev_priv->fbdev->helper);
 }
 
 void intel_fbdev_restore_mode(struct drm_device *dev)
@@ -531,7 +657,7 @@ void intel_fbdev_restore_mode(struct drm_device *dev)
         int ret;
         struct drm_i915_private *dev_priv = dev->dev_private;
 
-        if (INTEL_INFO(dev)->num_pipes == 0)
+        if (!dev_priv->fbdev)
                 return;
 
         drm_modeset_lock_all(dev);