crypto: ccp - Allow for selective disablement of crypto API algorithms

Introduce module parameters that allow for disabling of a
crypto algorithm by not registering the algorithm with the
crypto API.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 25 insertions, 12 deletions

diff --git a/drivers/crypto/ccp/ccp-crypto-main.c b/drivers/crypto/ccp/ccp-crypto-main.c
index 2636f044789d..b3f22b07b5bd 100644
--- a/drivers/crypto/ccp/ccp-crypto-main.c
+++ b/drivers/crypto/ccp/ccp-crypto-main.c
@@ -11,6 +11,7 @@
  */
 
 #include <linux/module.h>
+#include <linux/moduleparam.h>
 #include <linux/kernel.h>
 #include <linux/list.h>
 #include <linux/ccp.h>
@@ -24,6 +25,14 @@ MODULE_LICENSE("GPL");
 MODULE_VERSION("1.0.0");
 MODULE_DESCRIPTION("AMD Cryptographic Coprocessor crypto API support");
 
+static unsigned int aes_disable;
+module_param(aes_disable, uint, 0444);
+MODULE_PARM_DESC(aes_disable, "Disable use of AES - any non-zero value");
+
+static unsigned int sha_disable;
+module_param(sha_disable, uint, 0444);
+MODULE_PARM_DESC(sha_disable, "Disable use of SHA - any non-zero value");
+
 
 /* List heads for the supported algorithms */
 static LIST_HEAD(hash_algs);
@@ -337,21 +346,25 @@ static int ccp_register_algs(void)
 {
         int ret;
 
-        ret = ccp_register_aes_algs(&cipher_algs);
-        if (ret)
-                return ret;
+        if (!aes_disable) {
+                ret = ccp_register_aes_algs(&cipher_algs);
+                if (ret)
+                        return ret;
 
-        ret = ccp_register_aes_cmac_algs(&hash_algs);
-        if (ret)
-                return ret;
+                ret = ccp_register_aes_cmac_algs(&hash_algs);
+                if (ret)
+                        return ret;
 
-        ret = ccp_register_aes_xts_algs(&cipher_algs);
-        if (ret)
-                return ret;
+                ret = ccp_register_aes_xts_algs(&cipher_algs);
+                if (ret)
+                        return ret;
+        }
 
-        ret = ccp_register_sha_algs(&hash_algs);
-        if (ret)
-                return ret;
+        if (!sha_disable) {
+                ret = ccp_register_sha_algs(&hash_algs);
+                if (ret)
+                        return ret;
+        }
 
         return 0;
 }