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, 1 deletions

diff --git a/drivers/crypto/padlock-aes.c b/drivers/crypto/padlock-aes.c
index 29b9469f8378..37b2e9406af6 100644
--- a/drivers/crypto/padlock-aes.c
+++ b/drivers/crypto/padlock-aes.c
@@ -19,6 +19,7 @@
 #include <linux/percpu.h>
 #include <linux/smp.h>
 #include <linux/slab.h>
+#include <asm/cpu_device_id.h>
 #include <asm/byteorder.h>
 #include <asm/processor.h>
 #include <asm/i387.h>
@@ -503,12 +504,18 @@ static struct crypto_alg cbc_aes_alg = {
         }
 };
 
+static struct x86_cpu_id padlock_cpu_id[] = {
+        X86_FEATURE_MATCH(X86_FEATURE_XCRYPT),
+        {}
+};
+MODULE_DEVICE_TABLE(x86cpu, padlock_cpu_id);
+
 static int __init padlock_init(void)
 {
         int ret;
         struct cpuinfo_x86 *c = &cpu_data(0);
 
-        if (!cpu_has_xcrypt)
+        if (!x86_match_cpu(padlock_cpu_id))
                 return -ENODEV;
 
         if (!cpu_has_xcrypt_enabled) {