[PATCH] Optimize D-cache alias handling on fork

Virtually index, physically tagged cache architectures can get away
without cache flushing when forking.  This patch adds a new cache
flushing function flush_cache_dup_mm(struct mm_struct *) which for the
moment I've implemented to do the same thing on all architectures
except on MIPS where it's a no-op.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/asm-sh/cpu-sh2/cacheflush.h b/include/asm-sh/cpu-sh2/cacheflush.h
index f556fa80ea97..2979efb26de3 100644
--- a/include/asm-sh/cpu-sh2/cacheflush.h
+++ b/include/asm-sh/cpu-sh2/cacheflush.h
@@ -15,6 +15,7 @@
  *
  *  - flush_cache_all() flushes entire cache
  *  - flush_cache_mm(mm) flushes the specified mm context's cache lines
+ *  - flush_cache_dup mm(mm) handles cache flushing when forking
  *  - flush_cache_page(mm, vmaddr, pfn) flushes a single page
  *  - flush_cache_range(vma, start, end) flushes a range of pages
  *
@@ -27,6 +28,7 @@
  */
 #define flush_cache_all()                       do { } while (0)
 #define flush_cache_mm(mm)                      do { } while (0)
+#define flush_cache_dup_mm(mm)                  do { } while (0)
 #define flush_cache_range(vma, start, end)      do { } while (0)
 #define flush_cache_page(vma, vmaddr, pfn)      do { } while (0)
 #define flush_dcache_page(page)                 do { } while (0)