Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux

Pull DRM updates from Dave Airlie:
 "This is the one and only next pull for 3.8, we had a regression we
  found last week, so I was waiting for that to resolve itself, and I
  ended up with some Intel fixes on top as well.

  Highlights:
   - new driver: nvidia tegra 20/30/hdmi support
   - radeon: add support for previously unused DMA engines, more HDMI
     regs, eviction speeds ups and fixes
   - i915: HSW support enable, agp removal on GEN6, seqno wrapping
   - exynos: IPP subsystem support (image post proc), HDMI
   - nouveau: display class reworking, nv20->40 z compression
   - ttm: start of locking fixes, rcu usage for lookups,
   - core: documentation updates, docbook integration, monotonic clock
     usage, move from connector to object properties"

* 'drm-next' of git://people.freedesktop.org/~airlied/linux: (590 commits)
  drm/exynos: add gsc ipp driver
  drm/exynos: add rotator ipp driver
  drm/exynos: add fimc ipp driver
  drm/exynos: add iommu support for ipp
  drm/exynos: add ipp subsystem
  drm/exynos: support device tree for fimd
  radeon: fix regression with eviction since evict caching changes
  drm/radeon: add more pedantic checks in the CP DMA checker
  drm/radeon: bump version for CS ioctl support for async DMA
  drm/radeon: enable the async DMA rings in the CS ioctl
  drm/radeon: add VM CS parser support for async DMA on cayman/TN/SI
  drm/radeon/kms: add evergreen/cayman CS parser for async DMA (v2)
  drm/radeon/kms: add 6xx/7xx CS parser for async DMA (v2)
  drm/radeon: fix htile buffer size computation for command stream checker
  drm/radeon: fix fence locking in the pageflip callback
  drm/radeon: make indirect register access concurrency-safe
  drm/radeon: add W|RREG32_IDX for MM_INDEX|DATA based mmio accesss
  drm/exynos: support extended screen coordinate of fimd
  drm/exynos: fix x, y coordinates for right bottom pixel
  drm/exynos: fix fb offset calculation for plane
  ...

2 files changed, 22 insertions, 0 deletions

diff --git a/include/linux/dma-attrs.h b/include/linux/dma-attrs.h
index f83f793223ff..c8e1831d7572 100644
--- a/include/linux/dma-attrs.h
+++ b/include/linux/dma-attrs.h
@@ -17,6 +17,7 @@ enum dma_attr {
         DMA_ATTR_NON_CONSISTENT,
         DMA_ATTR_NO_KERNEL_MAPPING,
         DMA_ATTR_SKIP_CPU_SYNC,
+        DMA_ATTR_FORCE_CONTIGUOUS,
         DMA_ATTR_MAX,
 };
 
diff --git a/include/linux/kref.h b/include/linux/kref.h
index 65af6887872f..4972e6e9ca93 100644
--- a/include/linux/kref.h
+++ b/include/linux/kref.h
@@ -111,4 +111,25 @@ static inline int kref_put_mutex(struct kref *kref,
         }
         return 0;
 }
+
+/**
+ * kref_get_unless_zero - Increment refcount for object unless it is zero.
+ * @kref: object.
+ *
+ * Return non-zero if the increment succeeded. Otherwise return 0.
+ *
+ * This function is intended to simplify locking around refcounting for
+ * objects that can be looked up from a lookup structure, and which are
+ * removed from that lookup structure in the object destructor.
+ * Operations on such objects require at least a read lock around
+ * lookup + kref_get, and a write lock around kref_put + remove from lookup
+ * structure. Furthermore, RCU implementations become extremely tricky.
+ * With a lookup followed by a kref_get_unless_zero *with return value check*
+ * locking in the kref_put path can be deferred to the actual removal from
+ * the lookup structure and RCU lookups become trivial.
+ */
+static inline int __must_check kref_get_unless_zero(struct kref *kref)
+{
+        return atomic_add_unless(&kref->refcount, 1, 0);
+}
 #endif /* _KREF_H_ */