From a72f0dbfd93159acdf2467e5a022b28f763061f6 Mon Sep 17 00:00:00 2001
From: Jan Glauber <jang@linux.vnet.ibm.com>
Date: Sat, 12 Jul 2008 15:42:11 +0800
Subject: [PATCH] crypto: s390 - Respect STFL bit
Bevore issuing any s390 crypto operation check whether the
CPACF facility is enabled in the facility list. That way a
virtualization layer can prevent usage of the CPACF facility
regardless of the availability of the crypto instructions.
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
---
arch/s390/crypto/crypt_s390.h | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/s390/crypto/crypt_s390.h b/arch/s390/crypto/crypt_s390.h
index 9992f95ef992a..0ef9829f2ad69 100644
--- a/arch/s390/crypto/crypt_s390.h
+++ b/arch/s390/crypto/crypt_s390.h
@@ -296,6 +296,10 @@ static inline int crypt_s390_func_available(int func)
unsigned char status[16];
int ret;
+ /* check if CPACF facility (bit 17) is available */
+ if (!(stfl() & 1ULL << (31 - 17)))
+ return 0;
+
switch (func & CRYPT_S390_OP_MASK) {
case CRYPT_S390_KM:
ret = crypt_s390_km(KM_QUERY, &status, NULL, NULL, 0);
--
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