initial_commit

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 00000000..a6040990
--- /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 = ((size_t)(0x21 * DX3(ip, 5, 5, 6)) >> 5) & D_MASK;
+		m_pos = dict[dindex];
+
+		if (m_pos < in)
+			goto literal;
+
+		if (ip == m_pos || ((size_t)(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 || ((size_t)(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");
+