mm: spinlock tree_lock

mapping->tree_lock has no read lockers.  convert the lock from an rwlock
to a spinlock.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Reviewed-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/include/asm-parisc/cacheflush.h b/include/asm-parisc/cacheflush.h
index 2f1e1b05440a..b7ca6dc7fddc 100644
--- a/include/asm-parisc/cacheflush.h
+++ b/include/asm-parisc/cacheflush.h
@@ -45,9 +45,9 @@ void flush_cache_mm(struct mm_struct *mm);
 extern void flush_dcache_page(struct page *page);
 
 #define flush_dcache_mmap_lock(mapping) \
-        write_lock_irq(&(mapping)->tree_lock)
+        spin_lock_irq(&(mapping)->tree_lock)
 #define flush_dcache_mmap_unlock(mapping) \
-        write_unlock_irq(&(mapping)->tree_lock)
+        spin_unlock_irq(&(mapping)->tree_lock)
 
 #define flush_icache_page(vma,page)     do {            \
         flush_kernel_dcache_page(page);                 \