1 files changed, 443 insertions, 0 deletions

diff --git a/lib/lz4/lz4_compress.c b/lib/lz4/lz4_compress.c
new file mode 100644
index 000000000000..fd94058bd7f9
--- /dev/null
+++ b/lib/lz4/lz4_compress.c
@@ -0,0 +1,443 @@
+/*
+ * 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/
+ *
+ *  Changed for kernel use by:
+ *  Chanho Min <chanho.min@lge.com>
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/lz4.h>
+#include <asm/unaligned.h>
+#include "lz4defs.h"
+
+/*
+ * LZ4_compressCtx :
+ * -----------------
+ * Compress 'isize' bytes from 'source' into an output buffer 'dest' of
+ * maximum size 'maxOutputSize'.  * If it cannot achieve it, compression
+ * will stop, and result of the function will be zero.
+ * return : the number of bytes written in buffer 'dest', or 0 if the
+ * compression fails
+ */
+static inline int lz4_compressctx(void *ctx,
+                const char *source,
+                char *dest,
+                int isize,
+                int maxoutputsize)
+{
+        HTYPE *hashtable = (HTYPE *)ctx;
+        const u8 *ip = (u8 *)source;
+#if LZ4_ARCH64
+        const BYTE * const base = ip;
+#else
+        const int base = 0;
+#endif
+        const u8 *anchor = ip;
+        const u8 *const iend = ip + isize;
+        const u8 *const mflimit = iend - MFLIMIT;
+        #define MATCHLIMIT (iend - LASTLITERALS)
+
+        u8 *op = (u8 *) dest;
+        u8 *const oend = op + maxoutputsize;
+        int length;
+        const int skipstrength = SKIPSTRENGTH;
+        u32 forwardh;
+        int lastrun;
+
+        /* Init */
+        if (isize < MINLENGTH)
+                goto _last_literals;
+
+        memset((void *)hashtable, 0, LZ4_MEM_COMPRESS);
+
+        /* First Byte */
+        hashtable[LZ4_HASH_VALUE(ip)] = ip - base;
+        ip++;
+        forwardh = LZ4_HASH_VALUE(ip);
+
+        /* Main Loop */
+        for (;;) {
+                int findmatchattempts = (1U << skipstrength) + 3;
+                const u8 *forwardip = ip;
+                const u8 *ref;
+                u8 *token;
+
+                /* Find a match */
+                do {
+                        u32 h = forwardh;
+                        int step = findmatchattempts++ >> skipstrength;
+                        ip = forwardip;
+                        forwardip = ip + step;
+
+                        if (unlikely(forwardip > mflimit))
+                                goto _last_literals;
+
+                        forwardh = LZ4_HASH_VALUE(forwardip);
+                        ref = base + hashtable[h];
+                        hashtable[h] = ip - base;
+                } while ((ref < ip - MAX_DISTANCE) || (A32(ref) != A32(ip)));
+
+                /* Catch up */
+                while ((ip > anchor) && (ref > (u8 *)source) &&
+                        unlikely(ip[-1] == ref[-1])) {
+                        ip--;
+                        ref--;
+                }
+
+                /* Encode Literal length */
+                length = (int)(ip - anchor);
+                token = op++;
+                /* check output limit */
+                if (unlikely(op + length + (2 + 1 + LASTLITERALS) +
+                        (length >> 8) > oend))
+                        return 0;
+
+                if (length >= (int)RUN_MASK) {
+                        int len;
+                        *token = (RUN_MASK << ML_BITS);
+                        len = length - RUN_MASK;
+                        for (; len > 254 ; len -= 255)
+                                *op++ = 255;
+                        *op++ = (u8)len;
+                } else
+                        *token = (length << ML_BITS);
+
+                /* Copy Literals */
+                LZ4_BLINDCOPY(anchor, op, length);
+_next_match:
+                /* Encode Offset */
+                LZ4_WRITE_LITTLEENDIAN_16(op, (u16)(ip - ref));
+
+                /* Start Counting */
+                ip += MINMATCH;
+                /* MinMatch verified */
+                ref += MINMATCH;
+                anchor = ip;
+                while (likely(ip < MATCHLIMIT - (STEPSIZE - 1))) {
+                        #if LZ4_ARCH64
+                        u64 diff = A64(ref) ^ A64(ip);
+                        #else
+                        u32 diff = A32(ref) ^ A32(ip);
+                        #endif
+                        if (!diff) {
+                                ip += STEPSIZE;
+                                ref += STEPSIZE;
+                                continue;
+                        }
+                        ip += LZ4_NBCOMMONBYTES(diff);
+                        goto _endcount;
+                }
+                #if LZ4_ARCH64
+                if ((ip < (MATCHLIMIT - 3)) && (A32(ref) == A32(ip))) {
+                        ip += 4;
+                        ref += 4;
+                }
+                #endif
+                if ((ip < (MATCHLIMIT - 1)) && (A16(ref) == A16(ip))) {
+                        ip += 2;
+                        ref += 2;
+                }
+                if ((ip < MATCHLIMIT) && (*ref == *ip))
+                        ip++;
+_endcount:
+                /* Encode MatchLength */
+                length = (int)(ip - anchor);
+                /* Check output limit */
+                if (unlikely(op + (1 + LASTLITERALS) + (length >> 8) > oend))
+                        return 0;
+                if (length >= (int)ML_MASK) {
+                        *token += ML_MASK;
+                        length -= ML_MASK;
+                        for (; length > 509 ; length -= 510) {
+                                *op++ = 255;
+                                *op++ = 255;
+                        }
+                        if (length > 254) {
+                                length -= 255;
+                                *op++ = 255;
+                        }
+                        *op++ = (u8)length;
+                } else
+                        *token += length;
+
+                /* Test end of chunk */
+                if (ip > mflimit) {
+                        anchor = ip;
+                        break;
+                }
+
+                /* Fill table */
+                hashtable[LZ4_HASH_VALUE(ip-2)] = ip - 2 - base;
+
+                /* Test next position */
+                ref = base + hashtable[LZ4_HASH_VALUE(ip)];
+                hashtable[LZ4_HASH_VALUE(ip)] = ip - base;
+                if ((ref > ip - (MAX_DISTANCE + 1)) && (A32(ref) == A32(ip))) {
+                        token = op++;
+                        *token = 0;
+                        goto _next_match;
+                }
+
+                /* Prepare next loop */
+                anchor = ip++;
+                forwardh = LZ4_HASH_VALUE(ip);
+        }
+
+_last_literals:
+        /* Encode Last Literals */
+        lastrun = (int)(iend - anchor);
+        if (((char *)op - dest) + lastrun + 1
+                + ((lastrun + 255 - RUN_MASK) / 255) > (u32)maxoutputsize)
+                return 0;
+
+        if (lastrun >= (int)RUN_MASK) {
+                *op++ = (RUN_MASK << ML_BITS);
+                lastrun -= RUN_MASK;
+                for (; lastrun > 254 ; lastrun -= 255)
+                        *op++ = 255;
+                *op++ = (u8)lastrun;
+        } else
+                *op++ = (lastrun << ML_BITS);
+        memcpy(op, anchor, iend - anchor);
+        op += iend - anchor;
+
+        /* End */
+        return (int)(((char *)op) - dest);
+}
+
+static inline int lz4_compress64kctx(void *ctx,
+                const char *source,
+                char *dest,
+                int isize,
+                int maxoutputsize)
+{
+        u16 *hashtable = (u16 *)ctx;
+        const u8 *ip = (u8 *) source;
+        const u8 *anchor = ip;
+        const u8 *const base = ip;
+        const u8 *const iend = ip + isize;
+        const u8 *const mflimit = iend - MFLIMIT;
+        #define MATCHLIMIT (iend - LASTLITERALS)
+
+        u8 *op = (u8 *) dest;
+        u8 *const oend = op + maxoutputsize;
+        int len, length;
+        const int skipstrength = SKIPSTRENGTH;
+        u32 forwardh;
+        int lastrun;
+
+        /* Init */
+        if (isize < MINLENGTH)
+                goto _last_literals;
+
+        memset((void *)hashtable, 0, LZ4_MEM_COMPRESS);
+
+        /* First Byte */
+        ip++;
+        forwardh = LZ4_HASH64K_VALUE(ip);
+
+        /* Main Loop */
+        for (;;) {
+                int findmatchattempts = (1U << skipstrength) + 3;
+                const u8 *forwardip = ip;
+                const u8 *ref;
+                u8 *token;
+
+                /* Find a match */
+                do {
+                        u32 h = forwardh;
+                        int step = findmatchattempts++ >> skipstrength;
+                        ip = forwardip;
+                        forwardip = ip + step;
+
+                        if (forwardip > mflimit)
+                                goto _last_literals;
+
+                        forwardh = LZ4_HASH64K_VALUE(forwardip);
+                        ref = base + hashtable[h];
+                        hashtable[h] = (u16)(ip - base);
+                } while (A32(ref) != A32(ip));
+
+                /* Catch up */
+                while ((ip > anchor) && (ref > (u8 *)source)
+                        && (ip[-1] == ref[-1])) {
+                        ip--;
+                        ref--;
+                }
+
+                /* Encode Literal length */
+                length = (int)(ip - anchor);
+                token = op++;
+                /* Check output limit */
+                if (unlikely(op + length + (2 + 1 + LASTLITERALS)
+                        + (length >> 8) > oend))
+                        return 0;
+                if (length >= (int)RUN_MASK) {
+                        *token = (RUN_MASK << ML_BITS);
+                        len = length - RUN_MASK;
+                        for (; len > 254 ; len -= 255)
+                                *op++ = 255;
+                        *op++ = (u8)len;
+                } else
+                        *token = (length << ML_BITS);
+
+                /* Copy Literals */
+                LZ4_BLINDCOPY(anchor, op, length);
+
+_next_match:
+                /* Encode Offset */
+                LZ4_WRITE_LITTLEENDIAN_16(op, (u16)(ip - ref));
+
+                /* Start Counting */
+                ip += MINMATCH;
+                /* MinMatch verified */
+                ref += MINMATCH;
+                anchor = ip;
+
+                while (ip < MATCHLIMIT - (STEPSIZE - 1)) {
+                        #if LZ4_ARCH64
+                        u64 diff = A64(ref) ^ A64(ip);
+                        #else
+                        u32 diff = A32(ref) ^ A32(ip);
+                        #endif
+
+                        if (!diff) {
+                                ip += STEPSIZE;
+                                ref += STEPSIZE;
+                                continue;
+                        }
+                        ip += LZ4_NBCOMMONBYTES(diff);
+                        goto _endcount;
+                }
+                #if LZ4_ARCH64
+                if ((ip < (MATCHLIMIT - 3)) && (A32(ref) == A32(ip))) {
+                        ip += 4;
+                        ref += 4;
+                }
+                #endif
+                if ((ip < (MATCHLIMIT - 1)) && (A16(ref) == A16(ip))) {
+                        ip += 2;
+                        ref += 2;
+                }
+                if ((ip < MATCHLIMIT) && (*ref == *ip))
+                        ip++;
+_endcount:
+
+                /* Encode MatchLength */
+                len = (int)(ip - anchor);
+                /* Check output limit */
+                if (unlikely(op + (1 + LASTLITERALS) + (len >> 8) > oend))
+                        return 0;
+                if (len >= (int)ML_MASK) {
+                        *token += ML_MASK;
+                        len -= ML_MASK;
+                        for (; len > 509 ; len -= 510) {
+                                *op++ = 255;
+                                *op++ = 255;
+                        }
+                        if (len > 254) {
+                                len -= 255;
+                                *op++ = 255;
+                        }
+                        *op++ = (u8)len;
+                } else
+                        *token += len;
+
+                /* Test end of chunk */
+                if (ip > mflimit) {
+                        anchor = ip;
+                        break;
+                }
+
+                /* Fill table */
+                hashtable[LZ4_HASH64K_VALUE(ip-2)] = (u16)(ip - 2 - base);
+
+                /* Test next position */
+                ref = base + hashtable[LZ4_HASH64K_VALUE(ip)];
+                hashtable[LZ4_HASH64K_VALUE(ip)] = (u16)(ip - base);
+                if (A32(ref) == A32(ip)) {
+                        token = op++;
+                        *token = 0;
+                        goto _next_match;
+                }
+
+                /* Prepare next loop */
+                anchor = ip++;
+                forwardh = LZ4_HASH64K_VALUE(ip);
+        }
+
+_last_literals:
+        /* Encode Last Literals */
+        lastrun = (int)(iend - anchor);
+        if (op + lastrun + 1 + (lastrun - RUN_MASK + 255) / 255 > oend)
+                return 0;
+        if (lastrun >= (int)RUN_MASK) {
+                *op++ = (RUN_MASK << ML_BITS);
+                lastrun -= RUN_MASK;
+                for (; lastrun > 254 ; lastrun -= 255)
+                        *op++ = 255;
+                *op++ = (u8)lastrun;
+        } else
+                *op++ = (lastrun << ML_BITS);
+        memcpy(op, anchor, iend - anchor);
+        op += iend - anchor;
+        /* End */
+        return (int)(((char *)op) - dest);
+}
+
+int lz4_compress(const unsigned char *src, size_t src_len,
+                        unsigned char *dst, size_t *dst_len, void *wrkmem)
+{
+        int ret = -1;
+        int out_len = 0;
+
+        if (src_len < LZ4_64KLIMIT)
+                out_len = lz4_compress64kctx(wrkmem, src, dst, src_len,
+                                lz4_compressbound(src_len));
+        else
+                out_len = lz4_compressctx(wrkmem, src, dst, src_len,
+                                lz4_compressbound(src_len));
+
+        if (out_len < 0)
+                goto exit;
+
+        *dst_len = out_len;
+
+        return 0;
+exit:
+        return ret;
+}
+EXPORT_SYMBOL_GPL(lz4_compress);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("LZ4 compressor");