--- /dev/null
+/*
+ * LZO1X Compressor from LZO
+ *
+ * Copyright (C) 1996-2012 Markus F.X.J. Oberhumer <markus@oberhumer.com>
+ *
+ * The full LZO package can be found at:
+ * http://www.oberhumer.com/opensource/lzo/
+ *
+ * Changed for Linux kernel use by:
+ * Nitin Gupta <nitingupta910@gmail.com>
+ * Richard Purdie <rpurdie@openedhand.com>
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <asm/unaligned.h>
+#include <linux/lzo.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,
+ size_t ti, void *wrkmem)
+{
+ const unsigned char *ip;
+ unsigned char *op;
+ const unsigned char * const in_end = in + in_len;
+ const unsigned char * const ip_end = in + in_len - 20;
+ const unsigned char *ii;
+ lzo_dict_t * const dict = (lzo_dict_t *) wrkmem;
+
+ op = out;
+ ip = in;
+ ii = ip;
+ ip += ti < 4 ? 4 - ti : 0;
+
+ for (;;) {
+ const unsigned char *m_pos;
+ size_t t, m_len, m_off;
+ u32 dv;
+literal:
+ ip += 1 + ((ip - ii) >> 5);
+next:
+ if (unlikely(ip >= ip_end))
+ break;
+ dv = get_unaligned_le32(ip);
+ t = ((dv * 0x1824429d) >> (32 - D_BITS)) & D_MASK;
+ m_pos = in + dict[t];
+ dict[t] = (lzo_dict_t) (ip - in);
+ if (unlikely(dv != get_unaligned_le32(m_pos)))
+ goto literal;
+
+ ii -= ti;
+ ti = 0;
+ t = ip - ii;
+ if (t != 0) {
+ if (t <= 3) {
+ op[-2] |= t;
+ COPY4(op, ii);
+ op += t;
+ } else if (t <= 16) {
+ *op++ = (t - 3);
+ COPY8(op, ii);
+ COPY8(op + 8, ii + 8);
+ op += t;
+ } else {
+ if (t <= 18) {
+ *op++ = (t - 3);
+ } else {
+ size_t tt = t - 18;
+ *op++ = 0;
+ while (unlikely(tt > 255)) {
+ tt -= 255;
+ *op++ = 0;
+ }
+ *op++ = tt;
+ }
+ do {
+ COPY8(op, ii);
+ COPY8(op + 8, ii + 8);
+ op += 16;
+ ii += 16;
+ t -= 16;
+ } while (t >= 16);
+ if (t > 0) do {
+ *op++ = *ii++;
+ } while (--t > 0);
+ }
+ }
+
+ m_len = 4;
+ {
+#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && defined(LZO_USE_CTZ64)
+ u64 v;
+ v = get_unaligned((const u64 *) (ip + m_len)) ^
+ get_unaligned((const u64 *) (m_pos + m_len));
+ if (unlikely(v == 0)) {
+ do {
+ m_len += 8;
+ v = get_unaligned((const u64 *) (ip + m_len)) ^
+ get_unaligned((const u64 *) (m_pos + m_len));
+ if (unlikely(ip + m_len >= ip_end))
+ goto m_len_done;
+ } while (v == 0);
+ }
+# if defined(__LITTLE_ENDIAN)
+ m_len += (unsigned) __builtin_ctzll(v) / 8;
+# elif defined(__BIG_ENDIAN)
+ m_len += (unsigned) __builtin_clzll(v) / 8;
+# else
+# error "missing endian definition"
+# endif
+#elif defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && defined(LZO_USE_CTZ32)
+ u32 v;
+ v = get_unaligned((const u32 *) (ip + m_len)) ^
+ get_unaligned((const u32 *) (m_pos + m_len));
+ if (unlikely(v == 0)) {
+ do {
+ m_len += 4;
+ v = get_unaligned((const u32 *) (ip + m_len)) ^
+ get_unaligned((const u32 *) (m_pos + m_len));
+ if (v != 0)
+ break;
+ m_len += 4;
+ v = get_unaligned((const u32 *) (ip + m_len)) ^
+ get_unaligned((const u32 *) (m_pos + m_len));
+ if (unlikely(ip + m_len >= ip_end))
+ goto m_len_done;
+ } while (v == 0);
+ }
+# if defined(__LITTLE_ENDIAN)
+ m_len += (unsigned) __builtin_ctz(v) / 8;
+# elif defined(__BIG_ENDIAN)
+ m_len += (unsigned) __builtin_clz(v) / 8;
+# else
+# error "missing endian definition"
+# endif
+#else
+ if (unlikely(ip[m_len] == m_pos[m_len])) {
+ do {
+ m_len += 1;
+ if (ip[m_len] != m_pos[m_len])
+ break;
+ m_len += 1;
+ if (ip[m_len] != m_pos[m_len])
+ break;
+ m_len += 1;
+ if (ip[m_len] != m_pos[m_len])
+ break;
+ m_len += 1;
+ if (ip[m_len] != m_pos[m_len])
+ break;
+ m_len += 1;
+ if (ip[m_len] != m_pos[m_len])
+ break;
+ m_len += 1;
+ if (ip[m_len] != m_pos[m_len])
+ break;
+ m_len += 1;
+ if (ip[m_len] != m_pos[m_len])
+ break;
+ m_len += 1;
+ if (unlikely(ip + m_len >= ip_end))
+ goto m_len_done;
+ } while (ip[m_len] == m_pos[m_len]);
+ }
+#endif
+ }
+m_len_done:
+
+ m_off = ip - m_pos;
+ ip += m_len;
+ ii = ip;
+ if (m_len <= M2_MAX_LEN && 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;
+ if (m_len <= M3_MAX_LEN)
+ *op++ = (M3_MARKER | (m_len - 2));
+ else {
+ m_len -= M3_MAX_LEN;
+ *op++ = M3_MARKER | 0;
+ while (unlikely(m_len > 255)) {
+ m_len -= 255;
+ *op++ = 0;
+ }
+ *op++ = (m_len);
+ }
+ *op++ = (m_off << 2);
+ *op++ = (m_off >> 6);
+ } else {
+ m_off -= 0x4000;
+ if (m_len <= M4_MAX_LEN)
+ *op++ = (M4_MARKER | ((m_off >> 11) & 8)
+ | (m_len - 2));
+ else {
+ m_len -= M4_MAX_LEN;
+ *op++ = (M4_MARKER | ((m_off >> 11) & 8));
+ while (unlikely(m_len > 255)) {
+ m_len -= 255;
+ *op++ = 0;
+ }
+ *op++ = (m_len);
+ }
+ *op++ = (m_off << 2);
+ *op++ = (m_off >> 6);
+ }
+ goto next;
+ }
+ *out_len = op - out;
+ return in_end - (ii - ti);
+}
+
+int lzo1x_1_compress(const unsigned char *in, size_t in_len,
+ unsigned char *out, size_t *out_len,
+ void *wrkmem)
+{
+ const unsigned char *ip = in;
+ unsigned char *op = out;
+ size_t l = in_len;
+ size_t t = 0;
+
+ while (l > 20) {
+ size_t ll = l <= (M4_MAX_OFFSET + 1) ? l : (M4_MAX_OFFSET + 1);
+ uintptr_t ll_end = (uintptr_t) ip + ll;
+ if ((ll_end + ((t + ll) >> 5)) <= ll_end)
+ break;
+ BUILD_BUG_ON(D_SIZE * sizeof(lzo_dict_t) > LZO1X_1_MEM_COMPRESS);
+ memset(wrkmem, 0, D_SIZE * sizeof(lzo_dict_t));
+ t = lzo1x_1_do_compress(ip, ll, op, out_len, t, wrkmem);
+ ip += ll;
+ op += *out_len;
+ l -= ll;
+ }
+ t += l;
+
+ if (t > 0) {
+ const unsigned char *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;
+ }
+ if (t >= 16) do {
+ COPY8(op, ii);
+ COPY8(op + 8, ii + 8);
+ op += 16;
+ ii += 16;
+ t -= 16;
+ } while (t >= 16);
+ if (t > 0) 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");
Code Review / kvmfornfv.git / blobdiff