1 files changed, 68 insertions, 0 deletions
diff --git a/drivers/block/zram/backend_842.c b/drivers/block/zram/backend_842.c
new file mode 100644
index 000000000000..005f3fcb9024
--- /dev/null
+++ b/drivers/block/zram/backend_842.c
@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/sw842.h>
+#include <linux/vmalloc.h>
+
+#include "backend_842.h"
+
+struct sw842_ctx {
+	void *mem;
+};
+
+static void destroy_842(void *ctx)
+{
+	struct sw842_ctx *zctx = ctx;
+
+	kfree(zctx->mem);
+	kfree(zctx);
+}
+
+static void *create_842(void)
+{
+	struct sw842_ctx *ctx;
+
+	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return NULL;
+
+	ctx->mem = kmalloc(SW842_MEM_COMPRESS, GFP_KERNEL);
+	if (!ctx->mem)
+		goto error;
+
+	return ctx;
+
+error:
+	destroy_842(ctx);
+	return NULL;
+}
+
+static int compress_842(void *ctx, const unsigned char *src, size_t src_len,
+			unsigned char *dst, size_t *dst_len)
+{
+	struct sw842_ctx *zctx = ctx;
+	unsigned int dlen = *dst_len;
+	int ret;
+
+	ret = sw842_compress(src, src_len, dst, &dlen, zctx->mem);
+	if (ret == 0)
+		*dst_len = dlen;
+	return ret;
+}
+
+static int decompress_842(void *ctx, const unsigned char *src, size_t src_len,
+			  unsigned char *dst, size_t dst_len)
+{
+	unsigned int dlen = dst_len;
+
+	return sw842_decompress(src, src_len, dst, &dlen);
+}
+
+const struct zcomp_ops backend_842 = {
+	.compress	= compress_842,
+	.decompress	= decompress_842,
+	.create_ctx	= create_842,
+	.destroy_ctx	= destroy_842,
+	.name		= "842",
+};