Merge tag 'staging-4.15-rc1' into v4l_for_linus

There are some conflicts between staging and media trees,
as reported by Stephen Rothwell <sfr@canb.auug.org.au>.

So, merge from staging.

* tag 'staging-4.15-rc1': (775 commits)
  staging: lustre: add SPDX identifiers to all lustre files
  staging: greybus: Remove redundant license text
  staging: greybus: add SPDX identifiers to all greybus driver files
  staging: ccree: simplify ioread/iowrite
  staging: ccree: simplify registers access
  staging: ccree: simplify error handling logic
  staging: ccree: remove dead code
  staging: ccree: handle limiting of DMA masks
  staging: ccree: copy IV to DMAable memory
  staging: fbtft: remove redundant initialization of buf
  staging: sm750fb: Fix parameter mistake in poke32
  staging: wilc1000: Fix bssid buffer offset in Txq
  staging: fbtft: fb_ssd1331: fix mirrored display
  staging: android: Fix checkpatch.pl error
  staging: greybus: loopback: convert loopback to use generic async operations
  staging: greybus: operation: add private data with get/set accessors
  staging: greybus: loopback: Fix iteration count on async path
  staging: greybus: loopback: Hold per-connection mutex across operations
  staging: greybus/loopback: use ktime_get() for time intervals
  staging: fsl-dpaa2/eth: Extra headroom in RX buffers
  ...

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

1 files changed, 16 insertions, 7 deletions

diff --git a/include/uapi/linux/membarrier.h b/include/uapi/linux/membarrier.h
index 6d47b3249d8a..4e01ad7ffe98 100644
--- a/include/uapi/linux/membarrier.h
+++ b/include/uapi/linux/membarrier.h
@@ -52,21 +52,30 @@
  *                          (non-running threads are de facto in such a
  *                          state). This only covers threads from the
  *                          same processes as the caller thread. This
- *                          command returns 0. The "expedited" commands
- *                          complete faster than the non-expedited ones,
- *                          they never block, but have the downside of
- *                          causing extra overhead.
+ *                          command returns 0 on success. The
+ *                          "expedited" commands complete faster than
+ *                          the non-expedited ones, they never block,
+ *                          but have the downside of causing extra
+ *                          overhead. A process needs to register its
+ *                          intent to use the private expedited command
+ *                          prior to using it, otherwise this command
+ *                          returns -EPERM.
+ * @MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED:
+ *                          Register the process intent to use
+ *                          MEMBARRIER_CMD_PRIVATE_EXPEDITED. Always
+ *                          returns 0.
  *
  * Command to be passed to the membarrier system call. The commands need to
  * be a single bit each, except for MEMBARRIER_CMD_QUERY which is assigned to
  * the value 0.
  */
 enum membarrier_cmd {
-        MEMBARRIER_CMD_QUERY                    = 0,
-        MEMBARRIER_CMD_SHARED                   = (1 << 0),
+        MEMBARRIER_CMD_QUERY                            = 0,
+        MEMBARRIER_CMD_SHARED                           = (1 << 0),
         /* reserved for MEMBARRIER_CMD_SHARED_EXPEDITED (1 << 1) */
         /* reserved for MEMBARRIER_CMD_PRIVATE (1 << 2) */
-        MEMBARRIER_CMD_PRIVATE_EXPEDITED        = (1 << 3),
+        MEMBARRIER_CMD_PRIVATE_EXPEDITED                = (1 << 3),
+        MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED       = (1 << 4),
 };
 
 #endif /* _UAPI_LINUX_MEMBARRIER_H */