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>

drivers/crypto/vmx/aes.c

@@ -84,6 +84,7 @@ static int p8_aes_setkey(struct crypto_tfm *tfm, const u8 *key,
 	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();
@@ -103,6 +104,7 @@ static void p8_aes_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
 		preempt_disable();
 		pagefault_disable();
 		enable_kernel_altivec();
+		enable_kernel_vsx();
 		aes_p8_encrypt(src, dst, &ctx->enc_key);
 		pagefault_enable();
 		preempt_enable();
@@ -119,6 +121,7 @@ static void p8_aes_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
 		preempt_disable();
 		pagefault_disable();
 		enable_kernel_altivec();
+		enable_kernel_vsx();
 		aes_p8_decrypt(src, dst, &ctx->dec_key);
 		pagefault_enable();
 		preempt_enable();