GRU Driver V3: fixes to resolve code review comments

Fixes problems identified in a code review:
	- add comment with high level dscription of the GRU
	- prepend "gru_" to all global names
	- delete unused function
	- couple of trivial bug fixes

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Jack Steiner <steiner@sgi.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/misc/sgi-gru/grutlbpurge.c b/drivers/misc/sgi-gru/grutlbpurge.c
index bb6b0e64e101..bcfd5425e2e6 100644
--- a/drivers/misc/sgi-gru/grutlbpurge.c
+++ b/drivers/misc/sgi-gru/grutlbpurge.c
@@ -242,7 +242,9 @@ static void gru_invalidate_range_end(struct mmu_notifier *mn,
         struct gru_mm_struct *gms = container_of(mn, struct gru_mm_struct,
                                                  ms_notifier);
 
-        atomic_dec(&gms->ms_range_active);
+        /* ..._and_test() provides needed barrier */
+        (void)atomic_dec_and_test(&gms->ms_range_active);
+
         wake_up_all(&gms->ms_wait_queue);
         gru_dbg(grudev, "gms %p, start 0x%lx, end 0x%lx\n", gms, start, end);
 }