zram: add lzo and lzorle compression backends support

Add s/w lzo/lzorle compression support.

Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Sergey Senozhatsky <[e-mail]>
Cc: Minchan Kim <[e-mail]>
Cc: Nick Terrell <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>

drivers/block/zram/Kconfig

···
 
 	  See Documentation/admin-guide/blockdev/zram.rst for more information.
 
+config ZRAM_BACKEND_LZO
+	bool "lzo and lzo-rle compression support"
+	depends on ZRAM
+	select LZO_COMPRESS
+	select LZO_DECOMPRESS
+
+choice
+	prompt "Default zram compressor"
+	default ZRAM_DEF_COMP_LZORLE
+	depends on ZRAM
+
+config ZRAM_DEF_COMP_LZORLE
+	bool "lzo-rle"
+	depends on ZRAM_BACKEND_LZO
+
+config ZRAM_DEF_COMP_LZO
+	bool "lzo"
+	depends on ZRAM_BACKEND_LZO
+
+endchoice
+
 config ZRAM_DEF_COMP
 	string
+	default "lzo-rle" if ZRAM_DEF_COMP_LZORLE
+	default "lzo" if ZRAM_DEF_COMP_LZO
 	default "unset-value"
 
 config ZRAM_WRITEBACK

drivers/block/zram/Makefile

···
 # SPDX-License-Identifier: GPL-2.0-only
+
 zram-y	:=	zcomp.o zram_drv.o
+
+zram-$(CONFIG_ZRAM_BACKEND_LZO)	+= backend_lzorle.o backend_lzo.o
 
 obj-$(CONFIG_ZRAM)	+=	zram.o

drivers/block/zram/backend_lzo.c

···
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/lzo.h>
+
+#include "backend_lzo.h"
+
+static void *lzo_create(void)
+{
+	return kzalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL);
+}
+
+static void lzo_destroy(void *ctx)
+{
+	kfree(ctx);
+}
+
+static int lzo_compress(void *ctx, const unsigned char *src, size_t src_len,
+			unsigned char *dst, size_t *dst_len)
+{
+	int ret;
+
+	ret = lzo1x_1_compress(src, src_len, dst, dst_len, ctx);
+	return ret == LZO_E_OK ? 0 : ret;
+}
+
+static int lzo_decompress(void *ctx, const unsigned char *src, size_t src_len,
+			  unsigned char *dst, size_t dst_len)
+{
+	int ret;
+
+	ret = lzo1x_decompress_safe(src, src_len, dst, &dst_len);
+	return ret == LZO_E_OK ? 0 : ret;
+}
+
+const struct zcomp_ops backend_lzo = {
+	.compress	= lzo_compress,
+	.decompress	= lzo_decompress,
+	.create_ctx	= lzo_create,
+	.destroy_ctx	= lzo_destroy,
+	.name		= "lzo",
+};

drivers/block/zram/backend_lzo.h

···
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#ifndef __BACKEND_LZO_H__
+#define __BACKEND_LZO_H__
+
+#include "zcomp.h"
+
+extern const struct zcomp_ops backend_lzo;
+
+#endif /* __BACKEND_LZO_H__ */

drivers/block/zram/backend_lzorle.c

···
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/lzo.h>
+
+#include "backend_lzorle.h"
+
+static void *lzorle_create(void)
+{
+	return kzalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL);
+}
+
+static void lzorle_destroy(void *ctx)
+{
+	kfree(ctx);
+}
+
+static int lzorle_compress(void *ctx, const unsigned char *src, size_t src_len,
+			   unsigned char *dst, size_t *dst_len)
+{
+	int ret;
+
+	ret = lzorle1x_1_compress(src, src_len, dst, dst_len, ctx);
+	return ret == LZO_E_OK ? 0 : ret;
+}
+
+static int lzorle_decompress(void *ctx, const unsigned char *src,
+			     size_t src_len, unsigned char *dst,
+			     size_t dst_len)
+{
+	int ret;
+
+	ret = lzo1x_decompress_safe(src, src_len, dst, &dst_len);
+	return ret == LZO_E_OK ? 0 : ret;
+}
+
+const struct zcomp_ops backend_lzorle = {
+	.compress	= lzorle_compress,
+	.decompress	= lzorle_decompress,
+	.create_ctx	= lzorle_create,
+	.destroy_ctx	= lzorle_destroy,
+	.name		= "lzo-rle",
+};

drivers/block/zram/backend_lzorle.h

···
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#ifndef __BACKEND_LZORLE_H__
+#define __BACKEND_LZORLE_H__
+
+#include "zcomp.h"
+
+extern const struct zcomp_ops backend_lzorle;
+
+#endif /* __BACKEND_LZORLE_H__ */

drivers/block/zram/zcomp.c

···
 
 #include "zcomp.h"
 
+#include "backend_lzo.h"
+#include "backend_lzorle.h"
+
 static const struct zcomp_ops *backends[] = {
+#if IS_ENABLED(CONFIG_ZRAM_BACKEND_LZO)
+	&backend_lzorle,
+	&backend_lzo,
+#endif
 	NULL
 };