zram: add zstd compression backend support

Add s/w zstd compression.

Link: https://lkml.kernel.org/r/20240712051850.484318-9-senozhatsky@chromium.org
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nick Terrell <terrelln@fb.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/drivers/block/zram/Kconfig b/drivers/block/zram/Kconfig
index 72751cb2b532205507b0316d23e2e569034b9d9f..ee4fe2ee341328a78de0ca6fc3e23935be108f19 100644 (file)
--- a/drivers/block/zram/Kconfig
+++ b/drivers/block/zram/Kconfig
@@ -33,6 +33,12 @@ config ZRAM_BACKEND_LZ4HC
        select LZ4HC_COMPRESS
        select LZ4_DECOMPRESS
 
+config ZRAM_BACKEND_ZSTD
+       bool "zstd compression support"
+       depends on ZRAM
+       select ZSTD_COMPRESS
+       select ZSTD_DECOMPRESS
+
 choice
        prompt "Default zram compressor"
        default ZRAM_DEF_COMP_LZORLE
@@ -54,6 +60,10 @@ config ZRAM_DEF_COMP_LZ4HC
        bool "lz4hc"
        depends on ZRAM_BACKEND_LZ4HC
 
+config ZRAM_DEF_COMP_ZSTD
+       bool "zstd"
+       depends on ZRAM_BACKEND_ZSTD
+
 endchoice
 
 config ZRAM_DEF_COMP
@@ -62,6 +72,7 @@ config ZRAM_DEF_COMP
        default "lzo" if ZRAM_DEF_COMP_LZO
        default "lz4" if ZRAM_DEF_COMP_LZ4
        default "lz4hc" if ZRAM_DEF_COMP_LZ4HC
+       default "zstd" if ZRAM_DEF_COMP_ZSTD
        default "unset-value"
 
 config ZRAM_WRITEBACK

diff --git a/drivers/block/zram/Makefile b/drivers/block/zram/Makefile
index 727c9d68e3e37b8a3c0d5e1d8e71271222034245..a2ca227e199ca70b3676c0a35157343fa862fdd8 100644 (file)
--- a/drivers/block/zram/Makefile
+++ b/drivers/block/zram/Makefile
@@ -5,5 +5,6 @@ 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
 zram-$(CONFIG_ZRAM_BACKEND_LZ4HC)      += backend_lz4hc.o
+zram-$(CONFIG_ZRAM_BACKEND_ZSTD)       += backend_zstd.o
 
 obj-$(CONFIG_ZRAM)     +=      zram.o

diff --git a/drivers/block/zram/backend_zstd.c b/drivers/block/zram/backend_zstd.c
new file mode 100644 (file)
index 0000000..abec68d
--- /dev/null
+++ b/drivers/block/zram/backend_zstd.c
@@ -0,0 +1,97 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/zstd.h>
+
+#include "backend_zstd.h"
+
+struct zstd_ctx {
+       zstd_cctx *cctx;
+       zstd_dctx *dctx;
+       void *cctx_mem;
+       void *dctx_mem;
+       s32 level;
+};
+
+static void zstd_destroy(void *ctx)
+{
+       struct zstd_ctx *zctx = ctx;
+
+       vfree(zctx->cctx_mem);
+       vfree(zctx->dctx_mem);
+       kfree(zctx);
+}
+
+static void *zstd_create(void)
+{
+       zstd_parameters params;
+       struct zstd_ctx *ctx;
+       size_t sz;
+
+       ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+       if (!ctx)
+               return NULL;
+
+       ctx->level = zstd_default_clevel();
+       params = zstd_get_params(ctx->level, 0);
+       sz = zstd_cctx_workspace_bound(&params.cParams);
+       ctx->cctx_mem = vzalloc(sz);
+       if (!ctx->cctx_mem)
+               goto error;
+
+       ctx->cctx = zstd_init_cctx(ctx->cctx_mem, sz);
+       if (!ctx->cctx)
+               goto error;
+
+       sz = zstd_dctx_workspace_bound();
+       ctx->dctx_mem = vzalloc(sz);
+       if (!ctx->dctx_mem)
+               goto error;
+
+       ctx->dctx = zstd_init_dctx(ctx->dctx_mem, sz);
+       if (!ctx->dctx)
+               goto error;
+
+       return ctx;
+
+error:
+       zstd_destroy(ctx);
+       return NULL;
+}
+
+static int zstd_compress(void *ctx, const unsigned char *src, size_t src_len,
+                        unsigned char *dst, size_t *dst_len)
+{
+       struct zstd_ctx *zctx = ctx;
+       const zstd_parameters params = zstd_get_params(zctx->level, 0);
+       size_t ret;
+
+       ret = zstd_compress_cctx(zctx->cctx, dst, *dst_len,
+                                src, src_len, &params);
+       if (zstd_is_error(ret))
+               return -EINVAL;
+       *dst_len = ret;
+       return 0;
+}
+
+static int zstd_decompress(void *ctx, const unsigned char *src, size_t src_len,
+                          unsigned char *dst, size_t dst_len)
+{
+       struct zstd_ctx *zctx = ctx;
+       size_t ret;
+
+       ret = zstd_decompress_dctx(zctx->dctx, dst, dst_len, src, src_len);
+       if (zstd_is_error(ret))
+               return -EINVAL;
+       return 0;
+}
+
+const struct zcomp_ops backend_zstd = {
+       .compress       = zstd_compress,
+       .decompress     = zstd_decompress,
+       .create_ctx     = zstd_create,
+       .destroy_ctx    = zstd_destroy,
+       .name           = "zstd",
+};

diff --git a/drivers/block/zram/backend_zstd.h b/drivers/block/zram/backend_zstd.h
new file mode 100644 (file)
index 0000000..10fdfff
--- /dev/null
+++ b/drivers/block/zram/backend_zstd.h
@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#ifndef __BACKEND_ZSTD_H__
+#define __BACKEND_ZSTD_H__
+
+#include "zcomp.h"
+
+extern const struct zcomp_ops backend_zstd;
+
+#endif /* __BACKEND_ZSTD_H__ */

diff --git a/drivers/block/zram/zcomp.c b/drivers/block/zram/zcomp.c
index 305d56278365cbba7c36c94d52f91c1a05dae0ef..b920462d7e565e68935a85ee31a44d8001778496 100644 (file)
--- a/drivers/block/zram/zcomp.c
+++ b/drivers/block/zram/zcomp.c
@@ -16,6 +16,7 @@
 #include "backend_lzorle.h"
 #include "backend_lz4.h"
 #include "backend_lz4hc.h"
+#include "backend_zstd.h"
 
 static const struct zcomp_ops *backends[] = {
 #if IS_ENABLED(CONFIG_ZRAM_BACKEND_LZO)
@@ -27,6 +28,9 @@ static const struct zcomp_ops *backends[] = {
 #endif
 #if IS_ENABLED(CONFIG_ZRAM_BACKEND_LZ4HC)
        &backend_lz4hc,
+#endif
+#if IS_ENABLED(CONFIG_ZRAM_BACKEND_ZSTD)
+       &backend_zstd,
 #endif
        NULL
 };