Merge tag 'topic/drm-misc-2016-10-24' of git://anongit.freedesktop.org/drm-intel into drm-next

First -misc pull for 4.10:
- drm_format rework from Laurent
- reservation patches from Chris that missed 4.9.
- aspect ratio support in infoframe helpers and drm mode/edid code
  (Shashank Sharma)
- rotation rework from Ville (first parts at least)
- another attempt at the CRC debugfs interface from Tomeu
- piles and piles of misc patches all over

* tag 'topic/drm-misc-2016-10-24' of git://anongit.freedesktop.org/drm-intel: (55 commits)
  drm: Use u64 for intermediate dotclock calculations
  drm/i915: Use the per-plane rotation property
  drm/omap: Use per-plane rotation property
  drm/omap: Set rotation property initial value to BIT(DRM_ROTATE_0) insted of 0
  drm/atmel-hlcdc: Use per-plane rotation property
  drm/arm: Use per-plane rotation property
  drm: Add support for optional per-plane rotation property
  drm/atomic: Reject attempts to use multiple rotation angles at once
  drm: Add drm_rotation_90_or_270()
  dma-buf/sync_file: hold reference to fence when creating sync_file
  drm/virtio: kconfig: Fixup white space.
  drm/fence: release fence reference when canceling event
  drm/i915: Handle early failure during intel_get_load_detect_pipe
  drm/fb_cma_helper: do not free fbdev if there is none
  drm: fix sparse warnings on undeclared symbols in crc debugfs
  gpu: Remove depends on RESET_CONTROLLER when not a provider
  i915: don't call drm_atomic_state_put on invalid pointer
  drm: Don't export the drm_fb_get_bpp_depth() function
  drm/arm: mali-dp: Replace drm_fb_get_bpp_depth() with drm_format_plane_cpp()
  drm: vmwgfx: Replace drm_fb_get_bpp_depth() with drm_format_info()
  ...

2 files changed, 53 insertions, 5 deletions

diff --git a/include/linux/fence.h b/include/linux/fence.h
index 0d763053f97a..c9c5ba98c302 100644
--- a/include/linux/fence.h
+++ b/include/linux/fence.h
@@ -183,6 +183,16 @@ void fence_release(struct kref *kref);
 void fence_free(struct fence *fence);
 
 /**
+ * fence_put - decreases refcount of the fence
+ * @fence:	[in]	fence to reduce refcount of
+ */
+static inline void fence_put(struct fence *fence)
+{
+	if (fence)
+		kref_put(&fence->refcount, fence_release);
+}
+
+/**
  * fence_get - increases refcount of the fence
  * @fence:	[in]	fence to increase refcount of
  *
@@ -210,13 +220,49 @@ static inline struct fence *fence_get_rcu(struct fence *fence)
 }
 
 /**
- * fence_put - decreases refcount of the fence
- * @fence:	[in]	fence to reduce refcount of
+ * fence_get_rcu_safe  - acquire a reference to an RCU tracked fence
+ * @fence:	[in]	pointer to fence to increase refcount of
+ *
+ * Function returns NULL if no refcount could be obtained, or the fence.
+ * This function handles acquiring a reference to a fence that may be
+ * reallocated within the RCU grace period (such as with SLAB_DESTROY_BY_RCU),
+ * so long as the caller is using RCU on the pointer to the fence.
+ *
+ * An alternative mechanism is to employ a seqlock to protect a bunch of
+ * fences, such as used by struct reservation_object. When using a seqlock,
+ * the seqlock must be taken before and checked after a reference to the
+ * fence is acquired (as shown here).
+ *
+ * The caller is required to hold the RCU read lock.
  */
-static inline void fence_put(struct fence *fence)
+static inline struct fence *fence_get_rcu_safe(struct fence * __rcu *fencep)
 {
-	if (fence)
-		kref_put(&fence->refcount, fence_release);
+	do {
+		struct fence *fence;
+
+		fence = rcu_dereference(*fencep);
+		if (!fence || !fence_get_rcu(fence))
+			return NULL;
+
+		/* The atomic_inc_not_zero() inside fence_get_rcu()
+		 * provides a full memory barrier upon success (such as now).
+		 * This is paired with the write barrier from assigning
+		 * to the __rcu protected fence pointer so that if that
+		 * pointer still matches the current fence, we know we
+		 * have successfully acquire a reference to it. If it no
+		 * longer matches, we are holding a reference to some other
+		 * reallocated pointer. This is possible if the allocator
+		 * is using a freelist like SLAB_DESTROY_BY_RCU where the
+		 * fence remains valid for the RCU grace period, but it
+		 * may be reallocated. When using such allocators, we are
+		 * responsible for ensuring the reference we get is to
+		 * the right fence, as below.
+		 */
+		if (fence == rcu_access_pointer(*fencep))
+			return rcu_pointer_handoff(fence);
+
+		fence_put(fence);
+	} while (1);
 }
 
 int fence_signal(struct fence *fence);
diff --git a/include/linux/hdmi.h b/include/linux/hdmi.h
index e9744202fa29..edbb4fc674ed 100644
--- a/include/linux/hdmi.h
+++ b/include/linux/hdmi.h
@@ -78,6 +78,8 @@ enum hdmi_picture_aspect {
 	HDMI_PICTURE_ASPECT_NONE,
 	HDMI_PICTURE_ASPECT_4_3,
 	HDMI_PICTURE_ASPECT_16_9,
+	HDMI_PICTURE_ASPECT_64_27,
+	HDMI_PICTURE_ASPECT_256_135,
 	HDMI_PICTURE_ASPECT_RESERVED,
 };