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>

1 files changed, 281 insertions, 0 deletions

diff --git a/include/crypto/acompress.h b/include/crypto/acompress.h
new file mode 100644
index 000000000000..14c70d887160
--- /dev/null
+++ b/include/crypto/acompress.h
@@ -0,0 +1,281 @@
+/*
+ * 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_H
+#define _CRYPTO_ACOMP_H
+#include <linux/crypto.h>
+
+#define CRYPTO_ACOMP_ALLOC_OUTPUT       0x00000001
+
+/**
+ * struct acomp_req - asynchronous (de)compression request
+ *
+ * @base:       Common attributes for asynchronous crypto requests
+ * @src:        Source Data
+ * @dst:        Destination data
+ * @slen:       Size of the input buffer
+ * @dlen:       Size of the output buffer and number of bytes produced
+ * @flags:      Internal flags
+ * @__ctx:      Start of private context data
+ */
+struct acomp_req {
+        struct crypto_async_request base;
+        struct scatterlist *src;
+        struct scatterlist *dst;
+        unsigned int slen;
+        unsigned int dlen;
+        u32 flags;
+        void *__ctx[] CRYPTO_MINALIGN_ATTR;
+};
+
+/**
+ * struct crypto_acomp - user-instantiated objects which encapsulate
+ * algorithms and core processing logic
+ *
+ * @base:       Common crypto API algorithm data structure
+ */
+struct crypto_acomp {
+        struct crypto_tfm base;
+};
+
+/**
+ * struct acomp_alg - asynchronous compression algorithm
+ *
+ * @compress:   Function performs a compress operation
+ * @decompress: Function performs a de-compress operation
+ * @dst_free:   Frees destination buffer if allocated inside the algorithm
+ * @init:       Initialize the cryptographic transformation object.
+ *              This function is used to initialize the cryptographic
+ *              transformation object. This function is called only once at
+ *              the instantiation time, right after the transformation context
+ *              was allocated. In case the cryptographic hardware has some
+ *              special requirements which need to be handled by software, this
+ *              function shall check for the precise requirement of the
+ *              transformation and put any software fallbacks in place.
+ * @exit:       Deinitialize the cryptographic transformation object. This is a
+ *              counterpart to @init, used to remove various changes set in
+ *              @init.
+ *
+ * @reqsize:    Context size for (de)compression requests
+ * @base:       Common crypto API algorithm data structure
+ */
+struct acomp_alg {
+        int (*compress)(struct acomp_req *req);
+        int (*decompress)(struct acomp_req *req);
+        void (*dst_free)(struct scatterlist *dst);
+        int (*init)(struct crypto_acomp *tfm);
+        void (*exit)(struct crypto_acomp *tfm);
+        unsigned int reqsize;
+        struct crypto_alg base;
+};
+
+/**
+ * DOC: Asynchronous Compression API
+ *
+ * The Asynchronous Compression API is used with the algorithms of type
+ * CRYPTO_ALG_TYPE_ACOMPRESS (listed as type "acomp" in /proc/crypto)
+ */
+
+/**
+ * crypto_alloc_acomp() -- allocate ACOMPRESS tfm handle
+ * @alg_name:   is the cra_name / name or cra_driver_name / driver name of the
+ *              compression algorithm e.g. "deflate"
+ * @type:       specifies the type of the algorithm
+ * @mask:       specifies the mask for the algorithm
+ *
+ * Allocate a handle for a compression algorithm. The returned struct
+ * crypto_acomp is the handle that is required for any subsequent
+ * API invocation for the compression operations.
+ *
+ * Return:      allocated handle in case of success; IS_ERR() is true in case
+ *              of an error, PTR_ERR() returns the error code.
+ */
+struct crypto_acomp *crypto_alloc_acomp(const char *alg_name, u32 type,
+                                        u32 mask);
+
+static inline struct crypto_tfm *crypto_acomp_tfm(struct crypto_acomp *tfm)
+{
+        return &tfm->base;
+}
+
+static inline struct acomp_alg *__crypto_acomp_alg(struct crypto_alg *alg)
+{
+        return container_of(alg, struct acomp_alg, base);
+}
+
+static inline struct crypto_acomp *__crypto_acomp_tfm(struct crypto_tfm *tfm)
+{
+        return container_of(tfm, struct crypto_acomp, base);
+}
+
+static inline struct acomp_alg *crypto_acomp_alg(struct crypto_acomp *tfm)
+{
+        return __crypto_acomp_alg(crypto_acomp_tfm(tfm)->__crt_alg);
+}
+
+static inline unsigned int crypto_acomp_reqsize(struct crypto_acomp *tfm)
+{
+        return crypto_acomp_alg(tfm)->reqsize;
+}
+
+static inline void acomp_request_set_tfm(struct acomp_req *req,
+                                         struct crypto_acomp *tfm)
+{
+        req->base.tfm = crypto_acomp_tfm(tfm);
+}
+
+static inline struct crypto_acomp *crypto_acomp_reqtfm(struct acomp_req *req)
+{
+        return __crypto_acomp_tfm(req->base.tfm);
+}
+
+/**
+ * crypto_free_acomp() -- free ACOMPRESS tfm handle
+ *
+ * @tfm:        ACOMPRESS tfm handle allocated with crypto_alloc_acomp()
+ */
+static inline void crypto_free_acomp(struct crypto_acomp *tfm)
+{
+        crypto_destroy_tfm(tfm, crypto_acomp_tfm(tfm));
+}
+
+static inline int crypto_has_acomp(const char *alg_name, u32 type, u32 mask)
+{
+        type &= ~CRYPTO_ALG_TYPE_MASK;
+        type |= CRYPTO_ALG_TYPE_ACOMPRESS;
+        mask |= CRYPTO_ALG_TYPE_MASK;
+
+        return crypto_has_alg(alg_name, type, mask);
+}
+
+/**
+ * acomp_request_alloc() -- allocates asynchronous (de)compression request
+ *
+ * @tfm:        ACOMPRESS tfm handle allocated with crypto_alloc_acomp()
+ *
+ * Return:      allocated handle in case of success or NULL in case of an error
+ */
+static inline struct acomp_req *acomp_request_alloc(struct crypto_acomp *tfm)
+{
+        struct acomp_req *req;
+
+        req = kzalloc(sizeof(*req) + crypto_acomp_reqsize(tfm), GFP_KERNEL);
+        if (likely(req))
+                acomp_request_set_tfm(req, tfm);
+
+        return req;
+}
+
+/**
+ * acomp_request_free() -- zeroize and free asynchronous (de)compression
+ *                         request as well as the output buffer if allocated
+ *                         inside the algorithm
+ *
+ * @req:        request to free
+ */
+static inline void acomp_request_free(struct acomp_req *req)
+{
+        struct crypto_acomp *tfm = crypto_acomp_reqtfm(req);
+        struct acomp_alg *alg = crypto_acomp_alg(tfm);
+
+        if (req->flags & CRYPTO_ACOMP_ALLOC_OUTPUT) {
+                alg->dst_free(req->dst);
+                req->dst = NULL;
+        }
+        kzfree(req);
+}
+
+/**
+ * acomp_request_set_callback() -- Sets an asynchronous callback
+ *
+ * Callback will be called when an asynchronous operation on a given
+ * request is finished.
+ *
+ * @req:        request that the callback will be set for
+ * @flgs:       specify for instance if the operation may backlog
+ * @cmlp:       callback which will be called
+ * @data:       private data used by the caller
+ */
+static inline void acomp_request_set_callback(struct acomp_req *req,
+                                              u32 flgs,
+                                              crypto_completion_t cmpl,
+                                              void *data)
+{
+        req->base.complete = cmpl;
+        req->base.data = data;
+        req->base.flags = flgs;
+}
+
+/**
+ * acomp_request_set_params() -- Sets request parameters
+ *
+ * Sets parameters required by an acomp operation
+ *
+ * @req:        asynchronous compress request
+ * @src:        pointer to input buffer scatterlist
+ * @dst:        pointer to output buffer scatterlist. If this is NULL, the
+ *              acomp layer will allocate the output memory
+ * @slen:       size of the input buffer
+ * @dlen:       size of the output buffer. If dst is NULL, this can be used by
+ *              the user to specify the maximum amount of memory to allocate
+ */
+static inline void acomp_request_set_params(struct acomp_req *req,
+                                            struct scatterlist *src,
+                                            struct scatterlist *dst,
+                                            unsigned int slen,
+                                            unsigned int dlen)
+{
+        req->src = src;
+        req->dst = dst;
+        req->slen = slen;
+        req->dlen = dlen;
+
+        if (!req->dst)
+                req->flags |= CRYPTO_ACOMP_ALLOC_OUTPUT;
+}
+
+/**
+ * crypto_acomp_compress() -- Invoke asynchronous compress operation
+ *
+ * Function invokes the asynchronous compress operation
+ *
+ * @req:        asynchronous compress request
+ *
+ * Return:      zero on success; error code in case of error
+ */
+static inline int crypto_acomp_compress(struct acomp_req *req)
+{
+        struct crypto_acomp *tfm = crypto_acomp_reqtfm(req);
+        struct acomp_alg *alg = crypto_acomp_alg(tfm);
+
+        return alg->compress(req);
+}
+
+/**
+ * crypto_acomp_decompress() -- Invoke asynchronous decompress operation
+ *
+ * Function invokes the asynchronous decompress operation
+ *
+ * @req:        asynchronous compress request
+ *
+ * Return:      zero on success; error code in case of error
+ */
+static inline int crypto_acomp_decompress(struct acomp_req *req)
+{
+        struct crypto_acomp *tfm = crypto_acomp_reqtfm(req);
+        struct acomp_alg *alg = crypto_acomp_alg(tfm);
+
+        return alg->decompress(req);
+}
+
+#endif