[CRYPTO] api: Added spawns

Spawns lock a specific crypto algorithm in place.  They can then be used
with crypto_spawn_tfm to allocate a tfm for that algorithm.  When the base
algorithm of a spawn is deregistered, all its spawns will be automatically
removed.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 15 insertions, 0 deletions

diff --git a/include/crypto/algapi.h b/include/crypto/algapi.h
index ffec530d52fb..b20f4bdb23ba 100644
--- a/include/crypto/algapi.h
+++ b/include/crypto/algapi.h
@@ -36,10 +36,21 @@ struct crypto_template {
         char name[CRYPTO_MAX_ALG_NAME];
 };
 
+struct crypto_spawn {
+        struct list_head list;
+        struct crypto_alg *alg;
+        struct crypto_instance *inst;
+};
+
 int crypto_register_template(struct crypto_template *tmpl);
 void crypto_unregister_template(struct crypto_template *tmpl);
 struct crypto_template *crypto_lookup_template(const char *name);
 
+int crypto_init_spawn(struct crypto_spawn *spawn, struct crypto_alg *alg,
+                      struct crypto_instance *inst);
+void crypto_drop_spawn(struct crypto_spawn *spawn);
+struct crypto_tfm *crypto_spawn_tfm(struct crypto_spawn *spawn);
+
 static inline void *crypto_instance_ctx(struct crypto_instance *inst)
 {
         return inst->__ctx;
diff --git a/include/linux/crypto.h b/include/linux/crypto.h
index 85f73c381913..40a6330abc8d 100644
--- a/include/linux/crypto.h
+++ b/include/linux/crypto.h
@@ -35,6 +35,8 @@
 #define CRYPTO_ALG_TYPE_COMPRESS        0x00000004
 
 #define CRYPTO_ALG_LARVAL               0x00000010
+#define CRYPTO_ALG_DEAD                 0x00000020
+#define CRYPTO_ALG_DYING                0x00000040
 
 /*
  * Transform masks and values (for crt_flags).
@@ -145,6 +147,8 @@ struct compress_alg {
 
 struct crypto_alg {
         struct list_head cra_list;
+        struct list_head cra_users;
+
         u32 cra_flags;
         unsigned int cra_blocksize;
         unsigned int cra_ctxsize;