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authorAlex Shi <alex.shi@linaro.org>2015-05-12 14:55:30 +0800
committerAlex Shi <alex.shi@linaro.org>2015-05-12 14:55:30 +0800
commit1f8fdf83fe376cc83e96e942689a6cfac01e9634 (patch)
tree5bd0c30cb23791f2806c85631fe45079e6917b9b /include/linux/lz4.h
parent8134585f1c33565ea5e752a7ba9323ed3e0921f3 (diff)
parent043787104c5b1386a96c317f2e82ecff257dd9c5 (diff)
downloadlinux-linaro-stable-1f8fdf83fe376cc83e96e942689a6cfac01e9634.tar.gz
Merge remote-tracking branch 'origin/v3.10/topic/zram' into linux-linaro-lsk
Conflicts: mm/Kconfig mm/Makefile
Diffstat (limited to 'include/linux/lz4.h')
-rw-r--r--include/linux/lz4.h87
1 files changed, 87 insertions, 0 deletions
diff --git a/include/linux/lz4.h b/include/linux/lz4.h
new file mode 100644
index 000000000000..4356686b0a39
--- /dev/null
+++ b/include/linux/lz4.h
@@ -0,0 +1,87 @@
+#ifndef __LZ4_H__
+#define __LZ4_H__
+/*
+ * LZ4 Kernel Interface
+ *
+ * Copyright (C) 2013, LG Electronics, Kyungsik Lee <kyungsik.lee@lge.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#define LZ4_MEM_COMPRESS (4096 * sizeof(unsigned char *))
+#define LZ4HC_MEM_COMPRESS (65538 * sizeof(unsigned char *))
+
+/*
+ * lz4_compressbound()
+ * Provides the maximum size that LZ4 may output in a "worst case" scenario
+ * (input data not compressible)
+ */
+static inline size_t lz4_compressbound(size_t isize)
+{
+ return isize + (isize / 255) + 16;
+}
+
+/*
+ * lz4_compress()
+ * src : source address of the original data
+ * src_len : size of the original data
+ * dst : output buffer address of the compressed data
+ * This requires 'dst' of size LZ4_COMPRESSBOUND.
+ * dst_len : is the output size, which is returned after compress done
+ * workmem : address of the working memory.
+ * This requires 'workmem' of size LZ4_MEM_COMPRESS.
+ * return : Success if return 0
+ * Error if return (< 0)
+ * note : Destination buffer and workmem must be already allocated with
+ * the defined size.
+ */
+int lz4_compress(const unsigned char *src, size_t src_len,
+ unsigned char *dst, size_t *dst_len, void *wrkmem);
+
+ /*
+ * lz4hc_compress()
+ * src : source address of the original data
+ * src_len : size of the original data
+ * dst : output buffer address of the compressed data
+ * This requires 'dst' of size LZ4_COMPRESSBOUND.
+ * dst_len : is the output size, which is returned after compress done
+ * workmem : address of the working memory.
+ * This requires 'workmem' of size LZ4HC_MEM_COMPRESS.
+ * return : Success if return 0
+ * Error if return (< 0)
+ * note : Destination buffer and workmem must be already allocated with
+ * the defined size.
+ */
+int lz4hc_compress(const unsigned char *src, size_t src_len,
+ unsigned char *dst, size_t *dst_len, void *wrkmem);
+
+/*
+ * lz4_decompress()
+ * src : source address of the compressed data
+ * src_len : is the input size, whcih is returned after decompress done
+ * dest : output buffer address of the decompressed data
+ * actual_dest_len: is the size of uncompressed data, supposing it's known
+ * return : Success if return 0
+ * Error if return (< 0)
+ * note : Destination buffer must be already allocated.
+ * slightly faster than lz4_decompress_unknownoutputsize()
+ */
+int lz4_decompress(const unsigned char *src, size_t *src_len,
+ unsigned char *dest, size_t actual_dest_len);
+
+/*
+ * lz4_decompress_unknownoutputsize()
+ * src : source address of the compressed data
+ * src_len : is the input size, therefore the compressed size
+ * dest : output buffer address of the decompressed data
+ * dest_len: is the max size of the destination buffer, which is
+ * returned with actual size of decompressed data after
+ * decompress done
+ * return : Success if return 0
+ * Error if return (< 0)
+ * note : Destination buffer must be already allocated.
+ */
+int lz4_decompress_unknownoutputsize(const unsigned char *src, size_t src_len,
+ unsigned char *dest, size_t *dest_len);
+#endif