Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / block / zram / zcomp.h

diff --git a/kernel/drivers/block/zram/zcomp.h b/kernel/drivers/block/zram/zcomp.h
new file mode 100644 (file)
index 0000000..c59d1fc
--- /dev/null
+++ b/kernel/drivers/block/zram/zcomp.h
@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2014 Sergey Senozhatsky.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#ifndef _ZCOMP_H_
+#define _ZCOMP_H_
+
+#include <linux/mutex.h>
+
+struct zcomp_strm {
+       /* compression/decompression buffer */
+       void *buffer;
+       /*
+        * The private data of the compression stream, only compression
+        * stream backend can touch this (e.g. compression algorithm
+        * working memory)
+        */
+       void *private;
+       /* used in multi stream backend, protected by backend strm_lock */
+       struct list_head list;
+};
+
+/* static compression backend */
+struct zcomp_backend {
+       int (*compress)(const unsigned char *src, unsigned char *dst,
+                       size_t *dst_len, void *private);
+
+       int (*decompress)(const unsigned char *src, size_t src_len,
+                       unsigned char *dst);
+
+       void *(*create)(void);
+       void (*destroy)(void *private);
+
+       const char *name;
+};
+
+/* dynamic per-device compression frontend */
+struct zcomp {
+       void *stream;
+       struct zcomp_backend *backend;
+
+       struct zcomp_strm *(*strm_find)(struct zcomp *comp);
+       void (*strm_release)(struct zcomp *comp, struct zcomp_strm *zstrm);
+       bool (*set_max_streams)(struct zcomp *comp, int num_strm);
+       void (*destroy)(struct zcomp *comp);
+};
+
+ssize_t zcomp_available_show(const char *comp, char *buf);
+
+struct zcomp *zcomp_create(const char *comp, int max_strm);
+void zcomp_destroy(struct zcomp *comp);
+
+struct zcomp_strm *zcomp_strm_find(struct zcomp *comp);
+void zcomp_strm_release(struct zcomp *comp, struct zcomp_strm *zstrm);
+
+int zcomp_compress(struct zcomp *comp, struct zcomp_strm *zstrm,
+               const unsigned char *src, size_t *dst_len);
+
+int zcomp_decompress(struct zcomp *comp, const unsigned char *src,
+               size_t src_len, unsigned char *dst);
+
+bool zcomp_set_max_streams(struct zcomp *comp, int num_strm);
+#endif /* _ZCOMP_H_ */