crypto: vmx - Adding enable_kernel_vsx() to access VSX instructions

vmx-crypto driver make use of some VSX instructions which are
only available if VSX is enabled. Running in cases where VSX
are not enabled vmx-crypto fails in a VSX exception.

In order to fix this enable_kernel_vsx() was added to turn on
VSX instructions for vmx-crypto.

Signed-off-by: Leonidas S. Barbosa <leosilva@linux.vnet.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/drivers/crypto/vmx/aes_cbc.c b/drivers/crypto/vmx/aes_cbc.c
index 7299995..0b8fe2e 100644
--- a/drivers/crypto/vmx/aes_cbc.c
+++ b/drivers/crypto/vmx/aes_cbc.c
@@ -85,6 +85,7 @@
 	preempt_disable();
 	pagefault_disable();
 	enable_kernel_altivec();
+	enable_kernel_vsx();
 	ret = aes_p8_set_encrypt_key(key, keylen * 8, &ctx->enc_key);
 	ret += aes_p8_set_decrypt_key(key, keylen * 8, &ctx->dec_key);
 	pagefault_enable();
@@ -115,6 +116,7 @@
 		preempt_disable();
 		pagefault_disable();
 		enable_kernel_altivec();
+		enable_kernel_vsx();
 
 		blkcipher_walk_init(&walk, dst, src, nbytes);
 		ret = blkcipher_walk_virt(desc, &walk);
@@ -155,6 +157,7 @@
 		preempt_disable();
 		pagefault_disable();
 		enable_kernel_altivec();
+		enable_kernel_vsx();
 
 		blkcipher_walk_init(&walk, dst, src, nbytes);
 		ret = blkcipher_walk_virt(desc, &walk);