]> git.karo-electronics.de Git - karo-tx-linux.git/commitdiff
decompressor: add LZ4 decompressor module
authorKyungsik Lee <kyungsik.lee@lge.com>
Sun, 10 Mar 2013 10:55:50 +0000 (21:55 +1100)
committerStephen Rothwell <sfr@canb.auug.org.au>
Tue, 12 Mar 2013 03:57:48 +0000 (14:57 +1100)
Add support for LZ4 decompression in the Linux Kernel.  LZ4 Decompression
APIs for kernel are based on LZ4 implementation by Yann Collet.

LZ4 homepage: http://fastcompression.blogspot.com/p/lz4.html
LZ4 source repository: http://code.google.com/p/lz4/

Signed-off-by: Kyungsik Lee <kyungsik.lee@lge.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Florian Fainelli <florian@openwrt.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
include/linux/lz4.h [new file with mode: 0644]
lib/lz4/lz4_decompress.c [new file with mode: 0644]
lib/lz4/lz4defs.h [new file with mode: 0644]

diff --git a/include/linux/lz4.h b/include/linux/lz4.h
new file mode 100644 (file)
index 0000000..7f6c75a
--- /dev/null
@@ -0,0 +1,51 @@
+#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.
+ */
+
+/*
+ * 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_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 char *src, size_t *src_len, 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 char *src, size_t src_len,
+               char *dest, size_t *dest_len);
+#endif
diff --git a/lib/lz4/lz4_decompress.c b/lib/lz4/lz4_decompress.c
new file mode 100644 (file)
index 0000000..dcc8975
--- /dev/null
@@ -0,0 +1,326 @@
+/*
+ * LZ4 Decompressor for Linux kernel
+ *
+ * Copyright (C) 2013 LG Electronics Co., Ltd. (http://www.lge.com/)
+ *
+ * Based on LZ4 implementation by Yann Collet.
+ *
+ * LZ4 - Fast LZ compression algorithm
+ * Copyright (C) 2011-2012, Yann Collet.
+ * BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ *  You can contact the author at :
+ *  - LZ4 homepage : http://fastcompression.blogspot.com/p/lz4.html
+ *  - LZ4 source repository : http://code.google.com/p/lz4/
+ */
+
+#ifndef STATIC
+#include <linux/module.h>
+#include <linux/kernel.h>
+#endif
+#include <linux/lz4.h>
+
+#include <asm/unaligned.h>
+
+#include "lz4defs.h"
+
+static int lz4_uncompress(const char *source, char *dest, int osize)
+{
+       const BYTE *ip = (const BYTE *) source;
+       const BYTE *ref;
+       BYTE *op = (BYTE *) dest;
+       BYTE * const oend = op + osize;
+       BYTE *cpy;
+       unsigned token;
+       size_t length;
+       size_t dec32table[] = {0, 3, 2, 3, 0, 0, 0, 0};
+#if LZ4_ARCH64
+       size_t dec64table[] = {0, 0, 0, -1, 0, 1, 2, 3};
+#endif
+
+       while (1) {
+
+               /* get runlength */
+               token = *ip++;
+               length = (token >> ML_BITS);
+               if (length == RUN_MASK) {
+                       size_t len;
+
+                       len = *ip++;
+                       for (; len == 255; length += 255)
+                               len = *ip++;
+                       length += len;
+               }
+
+               /* copy literals */
+               cpy = op + length;
+               if (unlikely(cpy > oend - COPYLENGTH)) {
+                       /*
+                        * Error: not enough place for another match
+                        * (min 4) + 5 literals
+                        */
+                       if (cpy != oend)
+                               goto _output_error;
+
+                       memcpy(op, ip, length);
+                       ip += length;
+                       break; /* EOF */
+               }
+               LZ4_WILDCOPY(ip, op, cpy);
+               ip -= (op - cpy);
+               op = cpy;
+
+               /* get offset */
+               LZ4_READ_LITTLEENDIAN_16(ref, cpy, ip);
+               ip += 2;
+
+               /* Error: offset create reference outside destination buffer */
+               if (unlikely(ref < (BYTE *const) dest))
+                       goto _output_error;
+
+               /* get matchlength */
+               length = token & ML_MASK;
+               if (length == ML_MASK) {
+                       for (; *ip == 255; length += 255)
+                               ip++;
+                       length += *ip++;
+               }
+
+               /* copy repeated sequence */
+               if (unlikely((op - ref) < STEPSIZE)) {
+#if LZ4_ARCH64
+                       size_t dec64 = dec64table[op - ref];
+#else
+                       const int dec64 = 0;
+#endif
+                       op[0] = ref[0];
+                       op[1] = ref[1];
+                       op[2] = ref[2];
+                       op[3] = ref[3];
+                       op += 4;
+                       ref += 4;
+                       ref -= dec32table[op-ref];
+                       PUT4(ref, op);
+                       op += STEPSIZE - 4;
+                       ref -= dec64;
+               } else {
+                       LZ4_COPYSTEP(ref, op);
+               }
+               cpy = op + length - (STEPSIZE - 4);
+               if (cpy > (oend - COPYLENGTH)) {
+
+                       /* Error: request to write beyond destination buffer */
+                       if (cpy > oend)
+                               goto _output_error;
+                       LZ4_SECURECOPY(ref, op, (oend - COPYLENGTH));
+                       while (op < cpy)
+                               *op++ = *ref++;
+                       op = cpy;
+                       /*
+                        * Check EOF (should never happen, since last 5 bytes
+                        * are supposed to be literals)
+                        */
+                       if (op == oend)
+                               goto _output_error;
+                       continue;
+               }
+               LZ4_SECURECOPY(ref, op, cpy);
+               op = cpy; /* correction */
+       }
+       /* end of decoding */
+       return (int) (((char *)ip) - source);
+
+       /* write overflow error detected */
+_output_error:
+       return (int) (-(((char *)ip) - source));
+}
+
+static int lz4_uncompress_unknownoutputsize(const char *source, char *dest,
+                               int isize, size_t maxoutputsize)
+{
+       const BYTE *ip = (const BYTE *) source;
+       const BYTE *const iend = ip + isize;
+       const BYTE *ref;
+
+
+       BYTE *op = (BYTE *) dest;
+       BYTE * const oend = op + maxoutputsize;
+       BYTE *cpy;
+
+       size_t dec32table[] = {0, 3, 2, 3, 0, 0, 0, 0};
+#if LZ4_ARCH64
+       size_t dec64table[] = {0, 0, 0, -1, 0, 1, 2, 3};
+#endif
+
+       /* Main Loop */
+       while (ip < iend) {
+
+               unsigned token;
+               size_t length;
+
+               /* get runlength */
+               token = *ip++;
+               length = (token >> ML_BITS);
+               if (length == RUN_MASK) {
+                       int s = 255;
+                       while ((ip < iend) && (s == 255)) {
+                               s = *ip++;
+                               length += s;
+                       }
+               }
+               /* copy literals */
+               cpy = op + length;
+               if ((cpy > oend - COPYLENGTH) ||
+                       (ip + length > iend - COPYLENGTH)) {
+
+                       if (cpy > oend)
+                               goto _output_error;/* writes beyond buffer */
+
+                       if (ip + length != iend)
+                               goto _output_error;/*
+                                                   * Error: LZ4 format requires
+                                                   * to consume all input
+                                                   * at this stage
+                                                   */
+                       memcpy(op, ip, length);
+                       op += length;
+                       break;/* Necessarily EOF, due to parsing restrictions */
+               }
+               LZ4_WILDCOPY(ip, op, cpy);
+               ip -= (op - cpy);
+               op = cpy;
+
+               /* get offset */
+               LZ4_READ_LITTLEENDIAN_16(ref, cpy, ip);
+               ip += 2;
+               if (ref < (BYTE * const) dest)
+                       goto _output_error;
+                       /*
+                        * Error : offset creates reference
+                        * outside of destination buffer
+                        */
+
+               /* get matchlength */
+               length = (token & ML_MASK);
+               if (length == ML_MASK) {
+                       while (ip < iend) {
+                               int s = *ip++;
+                               length += s;
+                               if (s == 255)
+                                       continue;
+                               break;
+                       }
+               }
+
+               /* copy repeated sequence */
+               if (unlikely((op - ref) < STEPSIZE)) {
+#if LZ4_ARCH64
+                       size_t dec64 = dec64table[op - ref];
+#else
+                       const int dec64 = 0;
+#endif
+                               op[0] = ref[0];
+                               op[1] = ref[1];
+                               op[2] = ref[2];
+                               op[3] = ref[3];
+                               op += 4;
+                               ref += 4;
+                               ref -= dec32table[op - ref];
+                               PUT4(ref, op);
+                               op += STEPSIZE - 4;
+                               ref -= dec64;
+               } else {
+                       LZ4_COPYSTEP(ref, op);
+               }
+               cpy = op + length - (STEPSIZE-4);
+               if (cpy > oend - COPYLENGTH) {
+                       if (cpy > oend)
+                               goto _output_error; /* write outside of buf */
+
+                       LZ4_SECURECOPY(ref, op, (oend - COPYLENGTH));
+                       while (op < cpy)
+                               *op++ = *ref++;
+                       op = cpy;
+                       /*
+                        * Check EOF (should never happen, since last 5 bytes
+                        * are supposed to be literals)
+                        */
+                       if (op == oend)
+                               goto _output_error;
+                       continue;
+               }
+               LZ4_SECURECOPY(ref, op, cpy);
+               op = cpy; /* correction */
+       }
+       /* end of decoding */
+       return (int) (((char *) op) - dest);
+
+       /* write overflow error detected */
+_output_error:
+       return (int) (-(((char *) ip) - source));
+}
+
+int lz4_decompress(const char *src, size_t *src_len, char *dest,
+               size_t actual_dest_len)
+{
+       int ret = -1;
+       int input_len = 0;
+
+       input_len = lz4_uncompress(src, dest, actual_dest_len);
+       if (input_len < 0)
+               goto exit_0;
+       *src_len = input_len;
+
+       return 0;
+exit_0:
+       return ret;
+}
+#ifndef STATIC
+EXPORT_SYMBOL_GPL(lz4_decompress);
+#endif
+
+int lz4_decompress_unknownoutputsize(const char *src, size_t src_len,
+               char *dest, size_t *dest_len)
+{
+       int ret = -1;
+       int out_len = 0;
+
+       out_len = lz4_uncompress_unknownoutputsize(src, dest, src_len,
+                                       *dest_len);
+       if (out_len < 0)
+               goto exit_0;
+       *dest_len = out_len;
+
+       return 0;
+exit_0:
+       return ret;
+}
+#ifndef STATIC
+EXPORT_SYMBOL_GPL(lz4_decompress_unknownoutputsize);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("LZ4 Decompressor");
+#endif
diff --git a/lib/lz4/lz4defs.h b/lib/lz4/lz4defs.h
new file mode 100644 (file)
index 0000000..43ac31d
--- /dev/null
@@ -0,0 +1,94 @@
+/*
+ * lz4defs.h -- architecture specific defines
+ *
+ * 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.
+ */
+
+/*
+ * Detects 64 bits mode
+ */
+#if (defined(__x86_64__) || defined(__x86_64) || defined(__amd64__) \
+       || defined(__ppc64__) || defined(__LP64__))
+#define LZ4_ARCH64 1
+#else
+#define LZ4_ARCH64 0
+#endif
+
+/*
+ * Architecture-specific macros
+ */
+#define BYTE   u8
+#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)            \
+       || defined(CONFIG_ARM) && __LINUX_ARM_ARCH__ >= 6       \
+       && defined(ARM_EFFICIENT_UNALIGNED_ACCESS)
+typedef struct _U32_S { u32 v; } U32_S;
+typedef struct _U64_S { u64 v; } U64_S;
+
+#define A32(x) (((U32_S *)(x))->v)
+#define A64(x) (((U64_S *)(x))->v)
+
+#define PUT4(s, d) (A32(d) = A32(s))
+#define PUT8(s, d) (A64(d) = A64(s))
+#else /* CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS */
+
+#define PUT4(s, d) \
+       put_unaligned(get_unaligned((const u32 *) s), (u32 *) d)
+#define PUT8(s, d) \
+       put_unaligned(get_unaligned((const u64 *) s), (u64 *) d)
+#endif
+
+#define COPYLENGTH 8
+#define ML_BITS  4
+#define ML_MASK  ((1U << ML_BITS) - 1)
+#define RUN_BITS (8 - ML_BITS)
+#define RUN_MASK ((1U << RUN_BITS) - 1)
+
+#if LZ4_ARCH64/* 64-bit */
+#define STEPSIZE 8
+
+#define LZ4_COPYSTEP(s, d)     \
+       do {                    \
+               PUT8(s, d);     \
+               d += 8;         \
+               s += 8;         \
+       } while (0)
+
+#define LZ4_COPYPACKET(s, d)   LZ4_COPYSTEP(s, d)
+
+#define LZ4_SECURECOPY(s, d, e)                        \
+       do {                                    \
+               if (d < e) {                    \
+                       LZ4_WILDCOPY(s, d, e);  \
+               }                               \
+       } while (0)
+
+#else  /* 32-bit */
+#define STEPSIZE 4
+
+#define LZ4_COPYSTEP(s, d)     \
+       do {                    \
+               PUT4(s, d);     \
+               d += 4;         \
+               s += 4;         \
+       } while (0)
+
+#define LZ4_COPYPACKET(s, d)           \
+       do {                            \
+               LZ4_COPYSTEP(s, d);     \
+               LZ4_COPYSTEP(s, d);     \
+       } while (0)
+
+#define LZ4_SECURECOPY LZ4_WILDCOPY
+#endif
+
+#define LZ4_READ_LITTLEENDIAN_16(d, s, p) \
+       (d = s - get_unaligned_le16(p))
+
+#define LZ4_WILDCOPY(s, d, e)          \
+       do {                            \
+               LZ4_COPYPACKET(s, d);   \
+       } while (d < e)