Add s/w lz4 compression support.
Signed-off-by: Sergey Senozhatsky <[email protected]>
---
drivers/block/zram/Kconfig | 11 +++++
drivers/block/zram/Makefile | 1 +
drivers/block/zram/backend_lz4.c | 73 ++++++++++++++++++++++++++++++++
drivers/block/zram/backend_lz4.h | 10 +++++
drivers/block/zram/zcomp.c | 4 ++
5 files changed, 99 insertions(+)
create mode 100644 drivers/block/zram/backend_lz4.c
create mode 100644 drivers/block/zram/backend_lz4.h
diff --git a/drivers/block/zram/Kconfig b/drivers/block/zram/Kconfig
index 5d329a887b12..f1e76fc8431a 100644
--- a/drivers/block/zram/Kconfig
+++ b/drivers/block/zram/Kconfig
@@ -20,6 +20,12 @@ config ZRAM_BACKEND_LZO
select LZO_COMPRESS
select LZO_DECOMPRESS
+config ZRAM_BACKEND_LZ4
+ bool "lz4 compression support"
+ depends on ZRAM
+ select LZ4_COMPRESS
+ select LZ4_DECOMPRESS
+
choice
prompt "Default zram compressor"
default ZRAM_DEF_COMP_LZORLE
@@ -33,12 +39,17 @@ config ZRAM_DEF_COMP_LZO
bool "lzo"
depends on ZRAM_BACKEND_LZO
+config ZRAM_DEF_COMP_LZ4
+ bool "lz4"
+ depends on ZRAM_BACKEND_LZ4
+
endchoice
config ZRAM_DEF_COMP
string
default "lzo-rle" if ZRAM_DEF_COMP_LZORLE
default "lzo" if ZRAM_DEF_COMP_LZO
+ default "lz4" if ZRAM_DEF_COMP_LZ4
default "unset-value"
config ZRAM_WRITEBACK
diff --git a/drivers/block/zram/Makefile b/drivers/block/zram/Makefile
index 2a3db3368af9..567f4434aee8 100644
--- a/drivers/block/zram/Makefile
+++ b/drivers/block/zram/Makefile
@@ -3,5 +3,6 @@
zram-y := zcomp.o zram_drv.o
zram-$(CONFIG_ZRAM_BACKEND_LZO) += backend_lzorle.o backend_lzo.o
+zram-$(CONFIG_ZRAM_BACKEND_LZ4) += backend_lz4.o
obj-$(CONFIG_ZRAM) += zram.o
diff --git a/drivers/block/zram/backend_lz4.c b/drivers/block/zram/backend_lz4.c
new file mode 100644
index 000000000000..6ea67511d782
--- /dev/null
+++ b/drivers/block/zram/backend_lz4.c
@@ -0,0 +1,73 @@
+#include <linux/kernel.h>
+#include <linux/lz4.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+
+#include "backend_lz4.h"
+
+struct lz4_ctx {
+ void *mem;
+ s32 level;
+};
+
+static void lz4_destroy(void *ctx)
+{
+ struct lz4_ctx *zctx = ctx;
+
+ vfree(zctx->mem);
+ kfree(zctx);
+}
+
+static void *lz4_create(void)
+{
+ struct lz4_ctx *ctx;
+
+ ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+ if (!ctx)
+ return NULL;
+
+ /* @FIXME: using a hardcoded LZ4_ACCELERATION_DEFAULT for now */
+ ctx->level = LZ4_ACCELERATION_DEFAULT;
+ ctx->mem = vmalloc(LZ4_MEM_COMPRESS);
+ if (!ctx->mem)
+ goto error;
+
+ return ctx;
+error:
+ lz4_destroy(ctx);
+ return NULL;
+}
+
+static int lz4_compress(void *ctx, const unsigned char *src,
+ unsigned char *dst, size_t *dst_len)
+{
+ struct lz4_ctx *zctx = ctx;
+ int ret;
+
+ ret = LZ4_compress_fast(src, dst, PAGE_SIZE, *dst_len,
+ zctx->level, zctx->mem);
+ if (!ret)
+ return -EINVAL;
+ *dst_len = ret;
+ return 0;
+}
+
+static int lz4_decompress(void *ctx, const unsigned char *src,
+ size_t src_len, unsigned char *dst)
+{
+ int dst_len = PAGE_SIZE;
+ int ret;
+
+ ret = LZ4_decompress_safe(src, dst, src_len, dst_len);
+ if (ret < 0)
+ return -EINVAL;
+ return 0;
+}
+
+struct zcomp_backend backend_lz4 = {
+ .compress = lz4_compress,
+ .decompress = lz4_decompress,
+ .create_ctx = lz4_create,
+ .destroy_ctx = lz4_destroy,
+ .name = "lz4",
+};
diff --git a/drivers/block/zram/backend_lz4.h b/drivers/block/zram/backend_lz4.h
new file mode 100644
index 000000000000..a5fb5564835c
--- /dev/null
+++ b/drivers/block/zram/backend_lz4.h
@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#ifndef __BACKEND_LZ4_H__
+#define __BACKEND_LZ4_H__
+
+#include "zcomp.h"
+
+extern struct zcomp_backend backend_lz4;
+
+#endif /* __BACKEND_LZ4_H__ */
diff --git a/drivers/block/zram/zcomp.c b/drivers/block/zram/zcomp.c
index 58fb3ac91f4b..902bdaf7e299 100644
--- a/drivers/block/zram/zcomp.c
+++ b/drivers/block/zram/zcomp.c
@@ -17,11 +17,15 @@
#include "backend_lzo.h"
#include "backend_lzorle.h"
+#include "backend_lz4.h"
static struct zcomp_backend *backends[] = {
#if IS_ENABLED(CONFIG_ZRAM_BACKEND_LZO)
&backend_lzorle,
&backend_lzo,
+#endif
+#if IS_ENABLED(CONFIG_ZRAM_BACKEND_LZ4)
+ &backend_lz4,
#endif
NULL
};
--
2.45.0.rc1.225.g2a3ae87e7f-goog