[PATCH v4 4/8] crypto/deflate: support contextless compression API

From: Joonsoo Kim
Date: Wed Oct 14 2015 - 03:40:49 EST


Now, contextless compression API is introduced and it can reduce
memory overhead in some cases. All compression algorithm will
support it.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
---
crypto/deflate.c | 96 ++++++++++++++++++++++++++++++++++++++++++++++++++------
1 file changed, 86 insertions(+), 10 deletions(-)

diff --git a/crypto/deflate.c b/crypto/deflate.c
index 95d8d37..7070438 100644
--- a/crypto/deflate.c
+++ b/crypto/deflate.c
@@ -32,6 +32,7 @@
#include <linux/interrupt.h>
#include <linux/mm.h>
#include <linux/net.h>
+#include <crypto/compress.h>

#define DEFLATE_DEF_LEVEL Z_DEFAULT_COMPRESSION
#define DEFLATE_DEF_WINBITS 11
@@ -101,9 +102,8 @@ static void deflate_decomp_exit(struct deflate_ctx *ctx)
vfree(ctx->decomp_stream.workspace);
}

-static int deflate_init(struct crypto_tfm *tfm)
+static int __deflate_init(void *ctx)
{
- struct deflate_ctx *ctx = crypto_tfm_ctx(tfm);
int ret;

ret = deflate_comp_init(ctx);
@@ -116,19 +116,54 @@ out:
return ret;
}

-static void deflate_exit(struct crypto_tfm *tfm)
+static void *deflate_alloc_context(struct crypto_ccomp *tfm)
+{
+ void *ctx;
+ int ret;
+
+ ctx = kzalloc(sizeof(struct deflate_ctx), GFP_KERNEL);
+ if (!ctx)
+ return ERR_PTR(-ENOMEM);
+
+ ret = __deflate_init(ctx);
+ if (ret) {
+ kfree(ctx);
+ return ERR_PTR(ret);
+ }
+
+ return ctx;
+}
+
+static int deflate_init(struct crypto_tfm *tfm)
{
struct deflate_ctx *ctx = crypto_tfm_ctx(tfm);

+ return __deflate_init(ctx);
+}
+
+static void __deflate_exit(void *ctx)
+{
deflate_comp_exit(ctx);
deflate_decomp_exit(ctx);
}

-static int deflate_compress(struct crypto_tfm *tfm, const u8 *src,
- unsigned int slen, u8 *dst, unsigned int *dlen)
+static void deflate_free_context(struct crypto_ccomp *tfm, void *ctx)
+{
+ __deflate_exit(ctx);
+}
+
+static void deflate_exit(struct crypto_tfm *tfm)
+{
+ struct deflate_ctx *ctx = crypto_tfm_ctx(tfm);
+
+ __deflate_exit(ctx);
+}
+
+static int __deflate_compress(const u8 *src, unsigned int slen,
+ u8 *dst, unsigned int *dlen, void *ctx)
{
int ret = 0;
- struct deflate_ctx *dctx = crypto_tfm_ctx(tfm);
+ struct deflate_ctx *dctx = ctx;
struct z_stream_s *stream = &dctx->comp_stream;

ret = zlib_deflateReset(stream);
@@ -153,12 +188,20 @@ out:
return ret;
}

-static int deflate_decompress(struct crypto_tfm *tfm, const u8 *src,
- unsigned int slen, u8 *dst, unsigned int *dlen)
+static int deflate_compress(struct crypto_tfm *tfm, const u8 *src,
+ unsigned int slen, u8 *dst, unsigned int *dlen)
+{
+ struct deflate_ctx *dctx = crypto_tfm_ctx(tfm);
+
+ return __deflate_compress(src, slen, dst, dlen, dctx);
+}
+
+static int __deflate_decompress(const u8 *src, unsigned int slen,
+ u8 *dst, unsigned int *dlen, void *ctx)
{

int ret = 0;
- struct deflate_ctx *dctx = crypto_tfm_ctx(tfm);
+ struct deflate_ctx *dctx = ctx;
struct z_stream_s *stream = &dctx->decomp_stream;

ret = zlib_inflateReset(stream);
@@ -194,6 +237,14 @@ out:
return ret;
}

+static int deflate_decompress(struct crypto_tfm *tfm, const u8 *src,
+ unsigned int slen, u8 *dst, unsigned int *dlen)
+{
+ struct deflate_ctx *dctx = crypto_tfm_ctx(tfm);
+
+ return __deflate_compress(src, slen, dst, dlen, dctx);
+}
+
static struct crypto_alg alg = {
.cra_name = "deflate",
.cra_flags = CRYPTO_ALG_TYPE_COMPRESS,
@@ -206,14 +257,39 @@ static struct crypto_alg alg = {
.coa_decompress = deflate_decompress } }
};

+static struct ccomp_alg ccomp = {
+ .alloc_context = deflate_alloc_context,
+ .free_context = deflate_free_context,
+ .compress = __deflate_compress,
+ .decompress = __deflate_decompress,
+ .base = {
+ .cra_name = "deflate",
+ .cra_flags = CRYPTO_ALG_TYPE_CCOMPRESS,
+ .cra_module = THIS_MODULE,
+ }
+};
+
static int __init deflate_mod_init(void)
{
- return crypto_register_alg(&alg);
+ int ret;
+
+ ret = crypto_register_alg(&alg);
+ if (ret)
+ return ret;
+
+ ret = crypto_register_ccomp(&ccomp);
+ if (ret) {
+ crypto_unregister_alg(&alg);
+ return ret;
+ }
+
+ return ret;
}

static void __exit deflate_mod_fini(void)
{
crypto_unregister_alg(&alg);
+ crypto_unregister_ccomp(&ccomp);
}

module_init(deflate_mod_init);
--
1.9.1

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