crypto: vmx - Convert to CPU feature based module autoloading

BugLink: http://bugs.launchpad.net/bugs/1651322

This patch utilises the GENERIC_CPU_AUTOPROBE infrastructure
to automatically load the vmx_crypto module if the CPU supports
it.
Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
(back ported from commit ccf5c442)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

Conflicts:
	drivers/crypto/vmx/Kconfig
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Acked-by: John Donnelly <john.donnelly@canonical.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

drivers/crypto/vmx/Kconfig

@@ -2,7 +2,7 @@ config CRYPTO_DEV_VMX_ENCRYPT
 	tristate "Encryption acceleration support on P8 CPU"
 	depends on CRYPTO_DEV_VMX
 	select CRYPTO_GHASH
-	default y
+	default m
 	help
 	  Support for VMX cryptographic acceleration instructions on Power8 CPU.
 	  This module supports acceleration for AES and GHASH in hardware. If you

drivers/crypto/vmx/vmx.c

@@ -23,6 +23,7 @@
 #include <linux/moduleparam.h>
 #include <linux/types.h>
 #include <linux/err.h>
+#include <linux/cpufeature.h>
 #include <linux/crypto.h>
 #include <asm/cputable.h>
 #include <crypto/internal/hash.h>
@@ -45,9 +46,6 @@ int __init p8_init(void)
 	int ret = 0;
 	struct crypto_alg **alg_it;
 
-	if (!(cur_cpu_spec->cpu_user_features2 & PPC_FEATURE2_VEC_CRYPTO))
-		return -ENODEV;
-
 	for (alg_it = algs; *alg_it; alg_it++) {
 		ret = crypto_register_alg(*alg_it);
 		printk(KERN_INFO "crypto_register_alg '%s' = %d\n",
@@ -80,7 +78,7 @@ void __exit p8_exit(void)
 	crypto_unregister_shash(&p8_ghash_alg);
 }
 
-module_init(p8_init);
+module_cpu_feature_match(PPC_MODULE_FEATURE_VEC_CRYPTO, p8_init);
 module_exit(p8_exit);
 
 MODULE_AUTHOR("Marcelo Cerri<mhcerri@br.ibm.com>");