[PATCH v6 07/23] zram: add lz4hc compression backend support

From: Sergey Senozhatsky
Date: Fri Jul 12 2024 - 01:22:45 EST


Add s/w lz4hc compression support.

Signed-off-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
---
drivers/block/zram/Kconfig | 11 +++++
drivers/block/zram/Makefile | 5 ++-
drivers/block/zram/backend_lz4hc.c | 72 ++++++++++++++++++++++++++++++
drivers/block/zram/backend_lz4hc.h | 10 +++++
drivers/block/zram/zcomp.c | 4 ++
5 files changed, 100 insertions(+), 2 deletions(-)
create mode 100644 drivers/block/zram/backend_lz4hc.c
create mode 100644 drivers/block/zram/backend_lz4hc.h

diff --git a/drivers/block/zram/Kconfig b/drivers/block/zram/Kconfig
index 28288e9432d4..72751cb2b532 100644
--- a/drivers/block/zram/Kconfig
+++ b/drivers/block/zram/Kconfig
@@ -27,6 +27,12 @@ config ZRAM_BACKEND_LZ4
select LZ4_COMPRESS
select LZ4_DECOMPRESS

+config ZRAM_BACKEND_LZ4HC
+ bool "lz4hc compression support"
+ depends on ZRAM
+ select LZ4HC_COMPRESS
+ select LZ4_DECOMPRESS
+
choice
prompt "Default zram compressor"
default ZRAM_DEF_COMP_LZORLE
@@ -44,6 +50,10 @@ config ZRAM_DEF_COMP_LZ4
bool "lz4"
depends on ZRAM_BACKEND_LZ4

+config ZRAM_DEF_COMP_LZ4HC
+ bool "lz4hc"
+ depends on ZRAM_BACKEND_LZ4HC
+
endchoice

config ZRAM_DEF_COMP
@@ -51,6 +61,7 @@ config ZRAM_DEF_COMP
default "lzo-rle" if ZRAM_DEF_COMP_LZORLE
default "lzo" if ZRAM_DEF_COMP_LZO
default "lz4" if ZRAM_DEF_COMP_LZ4
+ default "lz4hc" if ZRAM_DEF_COMP_LZ4HC
default "unset-value"

config ZRAM_WRITEBACK
diff --git a/drivers/block/zram/Makefile b/drivers/block/zram/Makefile
index 567f4434aee8..727c9d68e3e3 100644
--- a/drivers/block/zram/Makefile
+++ b/drivers/block/zram/Makefile
@@ -2,7 +2,8 @@

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
+zram-$(CONFIG_ZRAM_BACKEND_LZO) += backend_lzorle.o backend_lzo.o
+zram-$(CONFIG_ZRAM_BACKEND_LZ4) += backend_lz4.o
+zram-$(CONFIG_ZRAM_BACKEND_LZ4HC) += backend_lz4hc.o

obj-$(CONFIG_ZRAM) += zram.o
diff --git a/drivers/block/zram/backend_lz4hc.c b/drivers/block/zram/backend_lz4hc.c
new file mode 100644
index 000000000000..536f7a0073c4
--- /dev/null
+++ b/drivers/block/zram/backend_lz4hc.c
@@ -0,0 +1,72 @@
+#include <linux/kernel.h>
+#include <linux/lz4.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+
+#include "backend_lz4hc.h"
+
+struct lz4hc_ctx {
+ void *mem;
+ s32 level;
+};
+
+static void lz4hc_destroy(void *ctx)
+{
+ struct lz4hc_ctx *zctx = ctx;
+
+ vfree(zctx->mem);
+ kfree(zctx);
+}
+
+static void *lz4hc_create(void)
+{
+ struct lz4hc_ctx *ctx;
+
+ ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+ if (!ctx)
+ return NULL;
+
+ /* @FIXME: using a hardcoded LZ4HC_DEFAULT_CLEVEL for now */
+ ctx->level = LZ4HC_DEFAULT_CLEVEL;
+ ctx->mem = vmalloc(LZ4HC_MEM_COMPRESS);
+ if (!ctx->mem)
+ goto error;
+
+ return ctx;
+error:
+ lz4hc_destroy(ctx);
+ return NULL;
+}
+
+static int lz4hc_compress(void *ctx, const unsigned char *src, size_t src_len,
+ unsigned char *dst, size_t *dst_len)
+{
+ struct lz4hc_ctx *zctx = ctx;
+ int ret;
+
+ ret = LZ4_compress_HC(src, dst, src_len, *dst_len,
+ zctx->level, zctx->mem);
+ if (!ret)
+ return -EINVAL;
+ *dst_len = ret;
+ return 0;
+}
+
+static int lz4hc_decompress(void *ctx, const unsigned char *src,
+ size_t src_len, unsigned char *dst, size_t dst_len)
+{
+ int ret;
+
+ ret = LZ4_decompress_safe(src, dst, src_len, dst_len);
+ if (ret < 0)
+ return -EINVAL;
+ return 0;
+}
+
+const struct zcomp_ops backend_lz4hc = {
+ .compress = lz4hc_compress,
+ .decompress = lz4hc_decompress,
+ .create_ctx = lz4hc_create,
+ .destroy_ctx = lz4hc_destroy,
+ .name = "lz4hc",
+};
diff --git a/drivers/block/zram/backend_lz4hc.h b/drivers/block/zram/backend_lz4hc.h
new file mode 100644
index 000000000000..6de03551ed4d
--- /dev/null
+++ b/drivers/block/zram/backend_lz4hc.h
@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#ifndef __BACKEND_LZ4HC_H__
+#define __BACKEND_LZ4HC_H__
+
+#include "zcomp.h"
+
+extern const struct zcomp_ops backend_lz4hc;
+
+#endif /* __BACKEND_LZ4HC_H__ */
diff --git a/drivers/block/zram/zcomp.c b/drivers/block/zram/zcomp.c
index 080cf1d001f0..305d56278365 100644
--- a/drivers/block/zram/zcomp.c
+++ b/drivers/block/zram/zcomp.c
@@ -15,6 +15,7 @@
#include "backend_lzo.h"
#include "backend_lzorle.h"
#include "backend_lz4.h"
+#include "backend_lz4hc.h"

static const struct zcomp_ops *backends[] = {
#if IS_ENABLED(CONFIG_ZRAM_BACKEND_LZO)
@@ -23,6 +24,9 @@ static const struct zcomp_ops *backends[] = {
#endif
#if IS_ENABLED(CONFIG_ZRAM_BACKEND_LZ4)
&backend_lz4,
+#endif
+#if IS_ENABLED(CONFIG_ZRAM_BACKEND_LZ4HC)
+ &backend_lz4hc,
#endif
NULL
};
--
2.45.2.993.g49e7a77208-goog