crypto/zram: Add lz4fast algorithm

> Up to 3 times faster than default lz4
> Uses LZ4_compress_fast level 32

arch/arm64/configs/a53x_defconfig

@@ -7827,6 +7827,7 @@ CONFIG_CRYPTO_DEFLATE=y
 CONFIG_CRYPTO_LZO=m
 # CONFIG_CRYPTO_842 is not set
 CONFIG_CRYPTO_LZ4=y
+CONFIG_CRYPTO_LZ4FAST=y
 # CONFIG_CRYPTO_LZ4HC is not set
 CONFIG_CRYPTO_ZSTD=y
 

crypto/Kconfig

@@ -1830,6 +1830,15 @@ config CRYPTO_LZ4
 	help
 	  This is the LZ4 algorithm.
 
+config CRYPTO_LZ4FAST
+        tristate "LZ4FAST compression algorithm"
+        select CRYPTO_ALGAPI
+        select CRYPTO_ACOMP2
+        select LZ4_COMPRESS
+        select LZ4_DECOMPRESS
+        help
+          This is the LZ4 fast mode algorithm.
+
 config CRYPTO_LZ4HC
 	tristate "LZ4HC compression algorithm"
 	select CRYPTO_ALGAPI

crypto/Makefile

@@ -159,6 +159,7 @@ obj-$(CONFIG_CRYPTO_CRCT10DIF) += crct10dif_common.o crct10dif_generic.o
 obj-$(CONFIG_CRYPTO_AUTHENC) += authenc.o authencesn.o
 obj-$(CONFIG_CRYPTO_LZO) += lzo.o lzo-rle.o
 obj-$(CONFIG_CRYPTO_LZ4) += lz4.o
+obj-$(CONFIG_CRYPTO_LZ4FAST) += lz4fast.o
 obj-$(CONFIG_CRYPTO_LZ4HC) += lz4hc.o
 obj-$(CONFIG_CRYPTO_XXHASH) += xxhash_generic.o
 obj-$(CONFIG_CRYPTO_842) += 842.o

crypto/lz4fast.c

@@ -0,0 +1,160 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Cryptographic API.
+ *
+ * Copyright (c) 2013 Chanho Min <chanho.min@lge.com>
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/crypto.h>
+#include <linux/vmalloc.h>
+#include <linux/lz4.h>
+#include <crypto/internal/scompress.h>
+
+struct lz4fast_ctx {
+	void *lz4fast_comp_mem;
+};
+
+static void *lz4fast_alloc_ctx(struct crypto_scomp *tfm)
+{
+	void *ctx;
+
+	ctx = vmalloc(LZ4_MEM_COMPRESS);
+	if (!ctx)
+		return ERR_PTR(-ENOMEM);
+
+	return ctx;
+}
+
+static int lz4fast_init(struct crypto_tfm *tfm)
+{
+	struct lz4fast_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	ctx->lz4fast_comp_mem = lz4fast_alloc_ctx(NULL);
+	if (IS_ERR(ctx->lz4fast_comp_mem))
+		return -ENOMEM;
+
+	return 0;
+}
+
+static void lz4fast_free_ctx(struct crypto_scomp *tfm, void *ctx)
+{
+	vfree(ctx);
+}
+
+static void lz4fast_exit(struct crypto_tfm *tfm)
+{
+	struct lz4fast_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	lz4fast_free_ctx(NULL, ctx->lz4fast_comp_mem);
+}
+
+static int __lz4fast_compress_crypto(const u8 *src, unsigned int slen,
+				 u8 *dst, unsigned int *dlen, void *ctx)
+{
+	int out_len = LZ4_compress_fast(src, dst,
+		slen, *dlen, LZ4FAST_DEFAULT_CLEVEL, ctx);
+
+	if (!out_len)
+		return -EINVAL;
+
+	*dlen = out_len;
+	return 0;
+}
+
+static int lz4fast_scompress(struct crypto_scomp *tfm, const u8 *src,
+			 unsigned int slen, u8 *dst, unsigned int *dlen,
+			 void *ctx)
+{
+	return __lz4fast_compress_crypto(src, slen, dst, dlen, ctx);
+}
+
+static int lz4fast_compress_crypto(struct crypto_tfm *tfm, const u8 *src,
+			       unsigned int slen, u8 *dst, unsigned int *dlen)
+{
+	struct lz4fast_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	return __lz4fast_compress_crypto(src, slen, dst, dlen, ctx->lz4fast_comp_mem);
+}
+
+static int __lz4fast_decompress_crypto(const u8 *src, unsigned int slen,
+				   u8 *dst, unsigned int *dlen, void *ctx)
+{
+	int out_len = LZ4_decompress_safe(src, dst, slen, *dlen);
+
+	if (out_len < 0)
+		return -EINVAL;
+
+	*dlen = out_len;
+	return 0;
+}
+
+static int lz4fast_sdecompress(struct crypto_scomp *tfm, const u8 *src,
+			   unsigned int slen, u8 *dst, unsigned int *dlen,
+			   void *ctx)
+{
+	return __lz4fast_decompress_crypto(src, slen, dst, dlen, NULL);
+}
+
+static int lz4fast_decompress_crypto(struct crypto_tfm *tfm, const u8 *src,
+				 unsigned int slen, u8 *dst,
+				 unsigned int *dlen)
+{
+	return __lz4fast_decompress_crypto(src, slen, dst, dlen, NULL);
+}
+
+static struct crypto_alg alg_lz4fast = {
+	.cra_name		= "lz4fast",
+	.cra_driver_name	= "lz4fast-generic",
+	.cra_flags		= CRYPTO_ALG_TYPE_COMPRESS,
+	.cra_ctxsize		= sizeof(struct lz4fast_ctx),
+	.cra_module		= THIS_MODULE,
+	.cra_init		= lz4fast_init,
+	.cra_exit		= lz4fast_exit,
+	.cra_u			= { .compress = {
+	.coa_compress		= lz4fast_compress_crypto,
+	.coa_decompress		= lz4fast_decompress_crypto } }
+};
+
+static struct scomp_alg scomp = {
+	.alloc_ctx		= lz4fast_alloc_ctx,
+	.free_ctx		= lz4fast_free_ctx,
+	.compress		= lz4fast_scompress,
+	.decompress		= lz4fast_sdecompress,
+	.base			= {
+		.cra_name	= "lz4fast",
+		.cra_driver_name = "lz4fast-scomp",
+		.cra_module	 = THIS_MODULE,
+	}
+};
+
+static int __init lz4fast_mod_init(void)
+{
+	int ret;
+
+	ret = crypto_register_alg(&alg_lz4fast);
+	if (ret)
+		return ret;
+
+	ret = crypto_register_scomp(&scomp);
+	if (ret) {
+		crypto_unregister_alg(&alg_lz4fast);
+		return ret;
+	}
+
+	return ret;
+}
+
+static void __exit lz4fast_mod_fini(void)
+{
+	crypto_unregister_alg(&alg_lz4fast);
+	crypto_unregister_scomp(&scomp);
+}
+
+subsys_initcall(lz4fast_mod_init);
+module_exit(lz4fast_mod_fini);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("LZ4FAST Compression Algorithm");
+MODULE_ALIAS_CRYPTO("lz4fast");

drivers/block/zram/zcomp.c

@@ -23,6 +23,9 @@ static const char * const backends[] = {
 #if IS_ENABLED(CONFIG_CRYPTO_LZ4HC)
 	"lz4hc",
 #endif
+#if IS_ENABLED(CONFIG_CRYPTO_LZ4FAST)
+        "lz4fast",
+#endif
 #if IS_ENABLED(CONFIG_CRYPTO_842)
 	"842",
 #endif

include/linux/lz4.h

@@ -79,6 +79,8 @@
 #define LZ4HC_HASHTABLESIZE (1 << LZ4HC_HASH_LOG)
 #define LZ4HC_HASH_MASK (LZ4HC_HASHTABLESIZE - 1)
 
+#define LZ4FAST_DEFAULT_CLEVEL                   32
+
 /*-************************************************************************
  *	STREAMING CONSTANTS AND STRUCTURES
  **************************************************************************/