crypto: Add support for x86 cpuid auto loading for x86 crypto drivers

Add support for auto-loading of crypto drivers based on cpuid features.
This enables auto-loading of the VIA and Intel specific drivers
for AES, hashing and CRCs.

Requires the earlier infrastructure patch to add x86 modinfo.
I kept it all in a single patch for now.

I dropped the printks when the driver cpuid doesn't match (imho
drivers never should print anything in such a case)

One drawback is that udev doesn't know if the drivers are used or not,
so they will be unconditionally loaded at boot up. That's better
than not loading them at all, like it often happens.

Cc: Dave Jones <davej@redhat.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Jen Axboe <axboe@kernel.dk>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Huang Ying <ying.huang@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Renninger <trenn@suse.de>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 8 insertions, 4 deletions

diff --git a/arch/x86/crypto/ghash-clmulni-intel_glue.c b/arch/x86/crypto/ghash-clmulni-intel_glue.c
index 976aa64d9a20..b4bf0a63b520 100644
--- a/arch/x86/crypto/ghash-clmulni-intel_glue.c
+++ b/arch/x86/crypto/ghash-clmulni-intel_glue.c
@@ -20,6 +20,7 @@
 #include <crypto/gf128mul.h>
 #include <crypto/internal/hash.h>
 #include <asm/i387.h>
+#include <asm/cpu_device_id.h>
 
 #define GHASH_BLOCK_SIZE        16
 #define GHASH_DIGEST_SIZE       16
@@ -294,15 +295,18 @@ static struct ahash_alg ghash_async_alg = {
         },
 };
 
+static const struct x86_cpu_id pcmul_cpu_id[] = {
+        X86_FEATURE_MATCH(X86_FEATURE_PCLMULQDQ), /* Pickle-Mickle-Duck */
+        {}
+};
+MODULE_DEVICE_TABLE(x86cpu, pcmul_cpu_id);
+
 static int __init ghash_pclmulqdqni_mod_init(void)
 {
         int err;
 
-        if (!cpu_has_pclmulqdq) {
-                printk(KERN_INFO "Intel PCLMULQDQ-NI instructions are not"
-                       " detected.\n");
+        if (!x86_match_cpu(pcmul_cpu_id))
                 return -ENODEV;
-        }
 
         err = crypto_register_shash(&ghash_alg);
         if (err)