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-rw-r--r--lib/lzo/lzo1x_compress.c226
1 files changed, 226 insertions, 0 deletions
diff --git a/lib/lzo/lzo1x_compress.c b/lib/lzo/lzo1x_compress.c
new file mode 100644
index 000000000000..c935f00073e9
--- /dev/null
+++ b/lib/lzo/lzo1x_compress.c
@@ -0,0 +1,226 @@
+/*
+ * LZO1X Compressor from MiniLZO
+ *
+ * Copyright (C) 1996-2005 Markus F.X.J. Oberhumer <markus@oberhumer.com>
+ *
+ * The full LZO package can be found at:
+ * http://www.oberhumer.com/opensource/lzo/
+ *
+ * Changed for kernel use by:
+ * Nitin Gupta <nitingupta910@gmail.com>
+ * Richard Purdie <rpurdie@openedhand.com>
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/lzo.h>
+#include <asm/unaligned.h>
+#include "lzodefs.h"
+
+static noinline size_t
+_lzo1x_1_do_compress(const unsigned char *in, size_t in_len,
+ unsigned char *out, size_t *out_len, void *wrkmem)
+{
+ const unsigned char * const in_end = in + in_len;
+ const unsigned char * const ip_end = in + in_len - M2_MAX_LEN - 5;
+ const unsigned char ** const dict = wrkmem;
+ const unsigned char *ip = in, *ii = ip;
+ const unsigned char *end, *m, *m_pos;
+ size_t m_off, m_len, dindex;
+ unsigned char *op = out;
+
+ ip += 4;
+
+ for (;;) {
+ dindex = ((0x21 * DX3(ip, 5, 5, 6)) >> 5) & D_MASK;
+ m_pos = dict[dindex];
+
+ if (m_pos < in)
+ goto literal;
+
+ if (ip == m_pos || (ip - m_pos) > M4_MAX_OFFSET)
+ goto literal;
+
+ m_off = ip - m_pos;
+ if (m_off <= M2_MAX_OFFSET || m_pos[3] == ip[3])
+ goto try_match;
+
+ dindex = (dindex & (D_MASK & 0x7ff)) ^ (D_HIGH | 0x1f);
+ m_pos = dict[dindex];
+
+ if (m_pos < in)
+ goto literal;
+
+ if (ip == m_pos || (ip - m_pos) > M4_MAX_OFFSET)
+ goto literal;
+
+ m_off = ip - m_pos;
+ if (m_off <= M2_MAX_OFFSET || m_pos[3] == ip[3])
+ goto try_match;
+
+ goto literal;
+
+try_match:
+ if (get_unaligned((const unsigned short *)m_pos)
+ == get_unaligned((const unsigned short *)ip)) {
+ if (likely(m_pos[2] == ip[2]))
+ goto match;
+ }
+
+literal:
+ dict[dindex] = ip;
+ ++ip;
+ if (unlikely(ip >= ip_end))
+ break;
+ continue;
+
+match:
+ dict[dindex] = ip;
+ if (ip != ii) {
+ size_t t = ip - ii;
+
+ if (t <= 3) {
+ op[-2] |= t;
+ } else if (t <= 18) {
+ *op++ = (t - 3);
+ } else {
+ size_t tt = t - 18;
+
+ *op++ = 0;
+ while (tt > 255) {
+ tt -= 255;
+ *op++ = 0;
+ }
+ *op++ = tt;
+ }
+ do {
+ *op++ = *ii++;
+ } while (--t > 0);
+ }
+
+ ip += 3;
+ if (m_pos[3] != *ip++ || m_pos[4] != *ip++
+ || m_pos[5] != *ip++ || m_pos[6] != *ip++
+ || m_pos[7] != *ip++ || m_pos[8] != *ip++) {
+ --ip;
+ m_len = ip - ii;
+
+ if (m_off <= M2_MAX_OFFSET) {
+ m_off -= 1;
+ *op++ = (((m_len - 1) << 5)
+ | ((m_off & 7) << 2));
+ *op++ = (m_off >> 3);
+ } else if (m_off <= M3_MAX_OFFSET) {
+ m_off -= 1;
+ *op++ = (M3_MARKER | (m_len - 2));
+ goto m3_m4_offset;
+ } else {
+ m_off -= 0x4000;
+
+ *op++ = (M4_MARKER | ((m_off & 0x4000) >> 11)
+ | (m_len - 2));
+ goto m3_m4_offset;
+ }
+ } else {
+ end = in_end;
+ m = m_pos + M2_MAX_LEN + 1;
+
+ while (ip < end && *m == *ip) {
+ m++;
+ ip++;
+ }
+ m_len = ip - ii;
+
+ if (m_off <= M3_MAX_OFFSET) {
+ m_off -= 1;
+ if (m_len <= 33) {
+ *op++ = (M3_MARKER | (m_len - 2));
+ } else {
+ m_len -= 33;
+ *op++ = M3_MARKER | 0;
+ goto m3_m4_len;
+ }
+ } else {
+ m_off -= 0x4000;
+ if (m_len <= M4_MAX_LEN) {
+ *op++ = (M4_MARKER
+ | ((m_off & 0x4000) >> 11)
+ | (m_len - 2));
+ } else {
+ m_len -= M4_MAX_LEN;
+ *op++ = (M4_MARKER
+ | ((m_off & 0x4000) >> 11));
+m3_m4_len:
+ while (m_len > 255) {
+ m_len -= 255;
+ *op++ = 0;
+ }
+
+ *op++ = (m_len);
+ }
+ }
+m3_m4_offset:
+ *op++ = ((m_off & 63) << 2);
+ *op++ = (m_off >> 6);
+ }
+
+ ii = ip;
+ if (unlikely(ip >= ip_end))
+ break;
+ }
+
+ *out_len = op - out;
+ return in_end - ii;
+}
+
+int lzo1x_1_compress(const unsigned char *in, size_t in_len, unsigned char *out,
+ size_t *out_len, void *wrkmem)
+{
+ const unsigned char *ii;
+ unsigned char *op = out;
+ size_t t;
+
+ if (unlikely(in_len <= M2_MAX_LEN + 5)) {
+ t = in_len;
+ } else {
+ t = _lzo1x_1_do_compress(in, in_len, op, out_len, wrkmem);
+ op += *out_len;
+ }
+
+ if (t > 0) {
+ ii = in + in_len - t;
+
+ if (op == out && t <= 238) {
+ *op++ = (17 + t);
+ } else if (t <= 3) {
+ op[-2] |= t;
+ } else if (t <= 18) {
+ *op++ = (t - 3);
+ } else {
+ size_t tt = t - 18;
+
+ *op++ = 0;
+ while (tt > 255) {
+ tt -= 255;
+ *op++ = 0;
+ }
+
+ *op++ = tt;
+ }
+ do {
+ *op++ = *ii++;
+ } while (--t > 0);
+ }
+
+ *op++ = M4_MARKER | 1;
+ *op++ = 0;
+ *op++ = 0;
+
+ *out_len = op - out;
+ return LZO_E_OK;
+}
+EXPORT_SYMBOL_GPL(lzo1x_1_compress);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("LZO1X-1 Compressor");
+