From: John Haxby <john.haxby@oracle.com>
Date: Wed, 14 Aug 2013 15:23:18 +0000 (+0100)
Subject: crypto: xor - Check for osxsave as well as avx in crypto/xor
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=edb6f29464afc65fc73767540b854abf63ae7144;p=linux.git

crypto: xor - Check for osxsave as well as avx in crypto/xor

This affects xen pv guests with sufficiently old versions of xen and
sufficiently new hardware.  On such a system, a guest with a btrfs
root won't even boot.

Signed-off-by: John Haxby <john.haxby@oracle.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
---

diff --git a/arch/x86/include/asm/xor_avx.h b/arch/x86/include/asm/xor_avx.h
index 7ea79c5fa1f21..492b29802f571 100644
--- a/arch/x86/include/asm/xor_avx.h
+++ b/arch/x86/include/asm/xor_avx.h
@@ -167,12 +167,12 @@ static struct xor_block_template xor_block_avx = {
 
 #define AVX_XOR_SPEED \
 do { \
-	if (cpu_has_avx) \
+	if (cpu_has_avx && cpu_has_osxsave) \
 		xor_speed(&xor_block_avx); \
 } while (0)
 
 #define AVX_SELECT(FASTEST) \
-	(cpu_has_avx ? &xor_block_avx : FASTEST)
+	(cpu_has_avx && cpu_has_osxsave ? &xor_block_avx : FASTEST)
 
 #else