crypto: acomp - add asynchronous compression api

Add acomp, an asynchronous compression api that uses scatterlist
buffers.

Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

include/crypto/internal/acompress.h

@@ -0,0 +1,66 @@
+/*
+ * Asynchronous Compression operations
+ *
+ * Copyright (c) 2016, Intel Corporation
+ * Authors: Weigang Li <weigang.li@intel.com>
+ *          Giovanni Cabiddu <giovanni.cabiddu@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ */
+#ifndef _CRYPTO_ACOMP_INT_H
+#define _CRYPTO_ACOMP_INT_H
+#include <crypto/acompress.h>
+
+/*
+ * Transform internal helpers.
+ */
+static inline void *acomp_request_ctx(struct acomp_req *req)
+{
+	return req->__ctx;
+}
+
+static inline void *acomp_tfm_ctx(struct crypto_acomp *tfm)
+{
+	return tfm->base.__crt_ctx;
+}
+
+static inline void acomp_request_complete(struct acomp_req *req,
+					  int err)
+{
+	req->base.complete(&req->base, err);
+}
+
+static inline const char *acomp_alg_name(struct crypto_acomp *tfm)
+{
+	return crypto_acomp_tfm(tfm)->__crt_alg->cra_name;
+}
+
+/**
+ * crypto_register_acomp() -- Register asynchronous compression algorithm
+ *
+ * Function registers an implementation of an asynchronous
+ * compression algorithm
+ *
+ * @alg:	algorithm definition
+ *
+ * Return:	zero on success; error code in case of error
+ */
+int crypto_register_acomp(struct acomp_alg *alg);
+
+/**
+ * crypto_unregister_acomp() -- Unregister asynchronous compression algorithm
+ *
+ * Function unregisters an implementation of an asynchronous
+ * compression algorithm
+ *
+ * @alg:	algorithm definition
+ *
+ * Return:	zero on success; error code in case of error
+ */
+int crypto_unregister_acomp(struct acomp_alg *alg);
+
+#endif