[PATCH v2 12/19] crypto: x86/sm3 - load based on CPU features

[Robert Elliott]

Like commit aa031b8f702e ("crypto: x86/sha512 - load based on CPU
features"), add module aliases for x86-optimized crypto modules:
        sm3
based on CPU feature bits so udev gets a chance to load them later in
the boot process when the filesystems are all running.

This commit covers a module that created rcu stall issues
due to kernel_fpu_begin/kernel_fpu_end calls.

Signed-off-by: Robert Elliott <elliott@xxxxxxx>
---
 arch/x86/crypto/sm3_avx_glue.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/arch/x86/crypto/sm3_avx_glue.c b/arch/x86/crypto/sm3_avx_glue.c
index ffb6d2f409ef..475b9637a06d 100644
--- a/arch/x86/crypto/sm3_avx_glue.c
+++ b/arch/x86/crypto/sm3_avx_glue.c
@@ -15,6 +15,7 @@
 #include <linux/types.h>
 #include <crypto/sm3.h>
 #include <crypto/sm3_base.h>
+#include <asm/cpu_device_id.h>
 #include <asm/simd.h>
 
 #define FPU_BYTES 4096U /* avoid kernel_fpu_begin/end scheduler/rcu stalls */
@@ -115,10 +116,19 @@ static struct shash_alg sm3_avx_alg = {
 	}
 };
 
+static const struct x86_cpu_id module_cpu_ids[] = {
+	X86_MATCH_FEATURE(X86_FEATURE_AVX, NULL),
+	{}
+};
+MODULE_DEVICE_TABLE(x86cpu, module_cpu_ids);
+
 static int __init sm3_avx_mod_init(void)
 {
 	const char *feature_name;
 
+	if (!x86_match_cpu(module_cpu_ids))
+		return -ENODEV;
+
 	if (!boot_cpu_has(X86_FEATURE_AVX)) {
 		pr_info("AVX instruction are not detected.\n");
 		return -ENODEV;
-- 
2.37.3