[v7,5/9] crypto: acomp - add support for lz4 via scomp

Commit Message

Cabiddu, Giovanni Sept. 13, 2016, 12:49 p.m. UTC

Add scomp backend for lz4 compression algorithm

Signed-off-by: Giovanni Cabiddu <[e-mail]>
---
 crypto/Kconfig |    1 +
 crypto/lz4.c   |  147 ++++++++++++++++++++++++++++++++++++++++++++++++++++----
 2 files changed, 138 insertions(+), 10 deletions(-)

Patch

diff --git a/crypto/Kconfig b/crypto/Kconfig
index d275591..e95cbbd 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -1606,6 +1606,7 @@  config CRYPTO_842
 config CRYPTO_LZ4
 	tristate "LZ4 compression algorithm"
 	select CRYPTO_ALGAPI
+	select CRYPTO_ACOMP2
 	select LZ4_COMPRESS
 	select LZ4_DECOMPRESS
 	help
diff --git a/crypto/lz4.c b/crypto/lz4.c
index aefbcea..8e4915d 100644
--- a/crypto/lz4.c
+++ b/crypto/lz4.c
@@ -22,37 +22,60 @@ 
 #include <linux/module.h>
 #include <linux/crypto.h>
 #include <linux/vmalloc.h>
+#include <crypto/scatterwalk.h>
 #include <linux/lz4.h>
+#include <crypto/internal/scompress.h>
+
+#define LZ4_SCRATCH_SIZE	131072
 
 struct lz4_ctx {
 	void *lz4_comp_mem;
 };
 
+static void * __percpu *lz4_src_scratches;
+static void * __percpu *lz4_dst_scratches;
+
+static void *lz4_alloc_ctx(struct crypto_scomp *tfm)
+{
+	void *ctx;
+
+	ctx = vmalloc(LZ4_MEM_COMPRESS);
+	if (!ctx)
+		return ERR_PTR(-ENOMEM);
+
+	return ctx;
+}
+
 static int lz4_init(struct crypto_tfm *tfm)
 {
 	struct lz4_ctx *ctx = crypto_tfm_ctx(tfm);
 
-	ctx->lz4_comp_mem = vmalloc(LZ4_MEM_COMPRESS);
-	if (!ctx->lz4_comp_mem)
+	ctx->lz4_comp_mem = lz4_alloc_ctx(NULL);
+	if (IS_ERR(ctx->lz4_comp_mem))
 		return -ENOMEM;
 
 	return 0;
 }
 
+static void lz4_free_ctx(struct crypto_scomp *tfm, void *ctx)
+{
+	vfree(ctx);
+}
+
 static void lz4_exit(struct crypto_tfm *tfm)
 {
 	struct lz4_ctx *ctx = crypto_tfm_ctx(tfm);
-	vfree(ctx->lz4_comp_mem);
+
+	lz4_free_ctx(NULL, ctx->lz4_comp_mem);
 }
 
-static int lz4_compress_crypto(struct crypto_tfm *tfm, const u8 *src,
-			    unsigned int slen, u8 *dst, unsigned int *dlen)
+static int __lz4_compress_crypto(const u8 *src, unsigned int slen,
+				 u8 *dst, unsigned int *dlen, void *ctx)
 {
-	struct lz4_ctx *ctx = crypto_tfm_ctx(tfm);
 	size_t tmp_len = *dlen;
 	int err;
 
-	err = lz4_compress(src, slen, dst, &tmp_len, ctx->lz4_comp_mem);
+	err = lz4_compress(src, slen, dst, &tmp_len, ctx);
 
 	if (err < 0)
 		return -EINVAL;
@@ -61,8 +84,16 @@  static int lz4_compress_crypto(struct crypto_tfm *tfm, const u8 *src,
 	return 0;
 }
 
-static int lz4_decompress_crypto(struct crypto_tfm *tfm, const u8 *src,
-			      unsigned int slen, u8 *dst, unsigned int *dlen)
+static int lz4_compress_crypto(struct crypto_tfm *tfm, const u8 *src,
+			       unsigned int slen, u8 *dst, unsigned int *dlen)
+{
+	struct lz4_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	return __lz4_compress_crypto(src, slen, dst, dlen, ctx->lz4_comp_mem);
+}
+
+static int __lz4_decompress_crypto(const u8 *src, unsigned int slen,
+				   u8 *dst, unsigned int *dlen, void *ctx)
 {
 	int err;
 	size_t tmp_len = *dlen;
@@ -76,6 +107,59 @@  static int lz4_decompress_crypto(struct crypto_tfm *tfm, const u8 *src,
 	return err;
 }
 
+static int lz4_decompress_crypto(struct crypto_tfm *tfm, const u8 *src,
+				 unsigned int slen, u8 *dst,
+				 unsigned int *dlen)
+{
+	return __lz4_decompress_crypto(src, slen, dst, dlen, NULL);
+}
+
+static int lz4_scomp_comp_decomp(struct crypto_scomp *tfm,
+				 struct scatterlist *src, unsigned int slen,
+				 struct scatterlist *dst, unsigned int *dlen,
+				 void *ctx, int dir)
+{
+	const int cpu = get_cpu();
+	u8 *scratch_src = *per_cpu_ptr(lz4_src_scratches, cpu);
+	u8 *scratch_dst = *per_cpu_ptr(lz4_dst_scratches, cpu);
+	int ret;
+
+	if (slen > LZ4_SCRATCH_SIZE || *dlen > LZ4_SCRATCH_SIZE) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	scatterwalk_map_and_copy(scratch_src, src, 0, slen, 0);
+	if (dir)
+		ret = __lz4_compress_crypto(scratch_src, slen, scratch_dst,
+					    dlen, ctx);
+	else
+		ret = __lz4_decompress_crypto(scratch_src, slen, scratch_dst,
+					      dlen, NULL);
+	if (!ret)
+		scatterwalk_map_and_copy(scratch_dst, dst, 0, *dlen, 1);
+
+out:
+	put_cpu();
+	return ret;
+}
+
+static int lz4_scomp_compress(struct crypto_scomp *tfm,
+			      struct scatterlist *src, unsigned int slen,
+			      struct scatterlist *dst, unsigned int *dlen,
+			      void *ctx)
+{
+	return lz4_scomp_comp_decomp(tfm, src, slen, dst, dlen, ctx, 1);
+}
+
+static int lz4_scomp_decompress(struct crypto_scomp *tfm,
+				struct scatterlist *src, unsigned int slen,
+				struct scatterlist *dst, unsigned int *dlen,
+				void *ctx)
+{
+	return lz4_scomp_comp_decomp(tfm, src, slen, dst, dlen, ctx, 0);
+}
+
 static struct crypto_alg alg_lz4 = {
 	.cra_name		= "lz4",
 	.cra_flags		= CRYPTO_ALG_TYPE_COMPRESS,
@@ -89,14 +173,57 @@  static struct crypto_alg alg_lz4 = {
 	.coa_decompress		= lz4_decompress_crypto } }
 };
 
+static struct scomp_alg scomp = {
+	.alloc_ctx		= lz4_alloc_ctx,
+	.free_ctx		= lz4_free_ctx,
+	.compress		= lz4_scomp_compress,
+	.decompress		= lz4_scomp_decompress,
+	.base			= {
+		.cra_name	= "lz4",
+		.cra_driver_name = "lz4-scomp",
+		.cra_module	 = THIS_MODULE,
+	}
+};
+
 static int __init lz4_mod_init(void)
 {
-	return crypto_register_alg(&alg_lz4);
+	int ret;
+
+	lz4_src_scratches = crypto_scomp_alloc_scratches(LZ4_SCRATCH_SIZE);
+	if (!lz4_src_scratches)
+		return -ENOMEM;
+
+	lz4_dst_scratches = crypto_scomp_alloc_scratches(LZ4_SCRATCH_SIZE);
+	if (!lz4_dst_scratches) {
+		ret = -ENOMEM;
+		goto error;
+	}
+
+	ret = crypto_register_alg(&alg_lz4);
+	if (ret)
+		goto error;
+
+	ret = crypto_register_scomp(&scomp);
+	if (ret) {
+		crypto_unregister_alg(&alg_lz4);
+		goto error;
+	}
+
+	return ret;
+
+error:
+	crypto_scomp_free_scratches(lz4_src_scratches);
+	crypto_scomp_free_scratches(lz4_dst_scratches);
+	return ret;
+
 }
 
 static void __exit lz4_mod_fini(void)
 {
 	crypto_unregister_alg(&alg_lz4);
+	crypto_unregister_scomp(&scomp);
+	crypto_scomp_free_scratches(lz4_src_scratches);
+	crypto_scomp_free_scratches(lz4_dst_scratches);
 }
 
 module_init(lz4_mod_init);