crypto: add crypto_has_kpp()

Add helper function to determine if a given key-agreement protocol
primitive is supported.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

crypto/kpp.c

@@ -104,6 +104,12 @@ int crypto_grab_kpp(struct crypto_kpp_spawn *spawn,
 }
 EXPORT_SYMBOL_GPL(crypto_grab_kpp);
 
+int crypto_has_kpp(const char *alg_name, u32 type, u32 mask)
+{
+	return crypto_type_has_alg(alg_name, &crypto_kpp_type, type, mask);
+}
+EXPORT_SYMBOL_GPL(crypto_has_kpp);
+
 static void kpp_prepare_alg(struct kpp_alg *alg)
 {
 	struct crypto_alg *base = &alg->base;

include/crypto/kpp.h

@@ -104,6 +104,8 @@ struct kpp_alg {
  */
 struct crypto_kpp *crypto_alloc_kpp(const char *alg_name, u32 type, u32 mask);
 
+int crypto_has_kpp(const char *alg_name, u32 type, u32 mask);
+
 static inline struct crypto_tfm *crypto_kpp_tfm(struct crypto_kpp *tfm)
 {
 	return &tfm->base;