From: Akinobu Mita <akinobu.mita@gmail.com>
Date: Sat, 27 Oct 2012 15:49:33 +0000 (+0900)
Subject: async_tx: use memchr_inv
X-Git-Tag: v3.9-rc1~12^2~77
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=2c88ae90939c2ef8ae80b07713b898c577b81598;p=platform%2Fkernel%2Flinux-stable.git

async_tx: use memchr_inv

Use memchr_inv() to check the specified page is filled with zero.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Dan Williams <djbw@fb.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
---

diff --git a/crypto/async_tx/async_xor.c b/crypto/async_tx/async_xor.c
index 154cc84..8ade0a0 100644
--- a/crypto/async_tx/async_xor.c
+++ b/crypto/async_tx/async_xor.c
@@ -230,9 +230,7 @@ EXPORT_SYMBOL_GPL(async_xor);
 
 static int page_is_zero(struct page *p, unsigned int offset, size_t len)
 {
-	char *a = page_address(p) + offset;
-	return ((*(u32 *) a) == 0 &&
-		memcmp(a, a + 4, len - 4) == 0);
+	return !memchr_inv(page_address(p) + offset, 0, len);
 }
 
 static inline struct dma_chan *