zram: add lz4hc compression backend support

Add s/w lz4hc compression support.

Link: https://lkml.kernel.org/r/20240902105656.1383858-8-senozhatsky@chromium.org
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nick Terrell <terrelln@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/drivers/block/zram/Kconfig b/drivers/block/zram/Kconfig
index f1e76fc8431a75f6f9b501269d9a2e5ce4e4a6f8..0d890a8d2dc4e1f201007eb2d41726b957c16693 100644 (file)
--- a/drivers/block/zram/Kconfig
+++ b/drivers/block/zram/Kconfig
@@ -26,6 +26,12 @@ 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
@@ -43,6 +49,10 @@ 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
@@ -50,6 +60,7 @@ 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 567f4434aee88831a657ecef24f34ea8f349eee9..727c9d68e3e37b8a3c0d5e1d8e71271222034245 100644 (file)
--- 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 (file)
index 0000000..536f7a0
--- /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 (file)
index 0000000..6de0355
--- /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 5da64e8fc798218faf104e9d3cac85089ccaa200..a06cdb9aa5670795708814d46c08ab58df9bc5d4 100644 (file)
--- 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
 };