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14#include <linux/module.h>
15#include <linux/kernel.h>
16#include <asm/unaligned.h>
17#include <linux/lzo.h>
18#include "lzodefs.h"
19
20static noinline size_t
21lzo1x_1_do_compress(const unsigned char *in, size_t in_len,
22 unsigned char *out, size_t *out_len,
23 size_t ti, void *wrkmem)
24{
25 const unsigned char *ip;
26 unsigned char *op;
27 const unsigned char * const in_end = in + in_len;
28 const unsigned char * const ip_end = in + in_len - 20;
29 const unsigned char *ii;
30 lzo_dict_t * const dict = (lzo_dict_t *) wrkmem;
31
32 op = out;
33 ip = in;
34 ii = ip;
35 ip += ti < 4 ? 4 - ti : 0;
36
37 for (;;) {
38 const unsigned char *m_pos;
39 size_t t, m_len, m_off;
40 u32 dv;
41literal:
42 ip += 1 + ((ip - ii) >> 5);
43next:
44 if (unlikely(ip >= ip_end))
45 break;
46 dv = get_unaligned_le32(ip);
47 t = ((dv * 0x1824429d) >> (32 - D_BITS)) & D_MASK;
48 m_pos = in + dict[t];
49 dict[t] = (lzo_dict_t) (ip - in);
50 if (unlikely(dv != get_unaligned_le32(m_pos)))
51 goto literal;
52
53 ii -= ti;
54 ti = 0;
55 t = ip - ii;
56 if (t != 0) {
57 if (t <= 3) {
58 op[-2] |= t;
59 COPY4(op, ii);
60 op += t;
61 } else if (t <= 16) {
62 *op++ = (t - 3);
63 COPY8(op, ii);
64 COPY8(op + 8, ii + 8);
65 op += t;
66 } else {
67 if (t <= 18) {
68 *op++ = (t - 3);
69 } else {
70 size_t tt = t - 18;
71 *op++ = 0;
72 while (unlikely(tt > 255)) {
73 tt -= 255;
74 *op++ = 0;
75 }
76 *op++ = tt;
77 }
78 do {
79 COPY8(op, ii);
80 COPY8(op + 8, ii + 8);
81 op += 16;
82 ii += 16;
83 t -= 16;
84 } while (t >= 16);
85 if (t > 0) do {
86 *op++ = *ii++;
87 } while (--t > 0);
88 }
89 }
90
91 m_len = 4;
92 {
93#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && defined(LZO_USE_CTZ64)
94 u64 v;
95 v = get_unaligned((const u64 *) (ip + m_len)) ^
96 get_unaligned((const u64 *) (m_pos + m_len));
97 if (unlikely(v == 0)) {
98 do {
99 m_len += 8;
100 v = get_unaligned((const u64 *) (ip + m_len)) ^
101 get_unaligned((const u64 *) (m_pos + m_len));
102 if (unlikely(ip + m_len >= ip_end))
103 goto m_len_done;
104 } while (v == 0);
105 }
106# if defined(__LITTLE_ENDIAN)
107 m_len += (unsigned) __builtin_ctzll(v) / 8;
108# elif defined(__BIG_ENDIAN)
109 m_len += (unsigned) __builtin_clzll(v) / 8;
110# else
111# error "missing endian definition"
112# endif
113#elif defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && defined(LZO_USE_CTZ32)
114 u32 v;
115 v = get_unaligned((const u32 *) (ip + m_len)) ^
116 get_unaligned((const u32 *) (m_pos + m_len));
117 if (unlikely(v == 0)) {
118 do {
119 m_len += 4;
120 v = get_unaligned((const u32 *) (ip + m_len)) ^
121 get_unaligned((const u32 *) (m_pos + m_len));
122 if (v != 0)
123 break;
124 m_len += 4;
125 v = get_unaligned((const u32 *) (ip + m_len)) ^
126 get_unaligned((const u32 *) (m_pos + m_len));
127 if (unlikely(ip + m_len >= ip_end))
128 goto m_len_done;
129 } while (v == 0);
130 }
131# if defined(__LITTLE_ENDIAN)
132 m_len += (unsigned) __builtin_ctz(v) / 8;
133# elif defined(__BIG_ENDIAN)
134 m_len += (unsigned) __builtin_clz(v) / 8;
135# else
136# error "missing endian definition"
137# endif
138#else
139 if (unlikely(ip[m_len] == m_pos[m_len])) {
140 do {
141 m_len += 1;
142 if (ip[m_len] != m_pos[m_len])
143 break;
144 m_len += 1;
145 if (ip[m_len] != m_pos[m_len])
146 break;
147 m_len += 1;
148 if (ip[m_len] != m_pos[m_len])
149 break;
150 m_len += 1;
151 if (ip[m_len] != m_pos[m_len])
152 break;
153 m_len += 1;
154 if (ip[m_len] != m_pos[m_len])
155 break;
156 m_len += 1;
157 if (ip[m_len] != m_pos[m_len])
158 break;
159 m_len += 1;
160 if (ip[m_len] != m_pos[m_len])
161 break;
162 m_len += 1;
163 if (unlikely(ip + m_len >= ip_end))
164 goto m_len_done;
165 } while (ip[m_len] == m_pos[m_len]);
166 }
167#endif
168 }
169m_len_done:
170
171 m_off = ip - m_pos;
172 ip += m_len;
173 ii = ip;
174 if (m_len <= M2_MAX_LEN && m_off <= M2_MAX_OFFSET) {
175 m_off -= 1;
176 *op++ = (((m_len - 1) << 5) | ((m_off & 7) << 2));
177 *op++ = (m_off >> 3);
178 } else if (m_off <= M3_MAX_OFFSET) {
179 m_off -= 1;
180 if (m_len <= M3_MAX_LEN)
181 *op++ = (M3_MARKER | (m_len - 2));
182 else {
183 m_len -= M3_MAX_LEN;
184 *op++ = M3_MARKER | 0;
185 while (unlikely(m_len > 255)) {
186 m_len -= 255;
187 *op++ = 0;
188 }
189 *op++ = (m_len);
190 }
191 *op++ = (m_off << 2);
192 *op++ = (m_off >> 6);
193 } else {
194 m_off -= 0x4000;
195 if (m_len <= M4_MAX_LEN)
196 *op++ = (M4_MARKER | ((m_off >> 11) & 8)
197 | (m_len - 2));
198 else {
199 m_len -= M4_MAX_LEN;
200 *op++ = (M4_MARKER | ((m_off >> 11) & 8));
201 while (unlikely(m_len > 255)) {
202 m_len -= 255;
203 *op++ = 0;
204 }
205 *op++ = (m_len);
206 }
207 *op++ = (m_off << 2);
208 *op++ = (m_off >> 6);
209 }
210 goto next;
211 }
212 *out_len = op - out;
213 return in_end - (ii - ti);
214}
215
216int lzo1x_1_compress(const unsigned char *in, size_t in_len,
217 unsigned char *out, size_t *out_len,
218 void *wrkmem)
219{
220 const unsigned char *ip = in;
221 unsigned char *op = out;
222 size_t l = in_len;
223 size_t t = 0;
224
225 while (l > 20) {
226 size_t ll = l <= (M4_MAX_OFFSET + 1) ? l : (M4_MAX_OFFSET + 1);
227 uintptr_t ll_end = (uintptr_t) ip + ll;
228 if ((ll_end + ((t + ll) >> 5)) <= ll_end)
229 break;
230 BUILD_BUG_ON(D_SIZE * sizeof(lzo_dict_t) > LZO1X_1_MEM_COMPRESS);
231 memset(wrkmem, 0, D_SIZE * sizeof(lzo_dict_t));
232 t = lzo1x_1_do_compress(ip, ll, op, out_len, t, wrkmem);
233 ip += ll;
234 op += *out_len;
235 l -= ll;
236 }
237 t += l;
238
239 if (t > 0) {
240 const unsigned char *ii = in + in_len - t;
241
242 if (op == out && t <= 238) {
243 *op++ = (17 + t);
244 } else if (t <= 3) {
245 op[-2] |= t;
246 } else if (t <= 18) {
247 *op++ = (t - 3);
248 } else {
249 size_t tt = t - 18;
250 *op++ = 0;
251 while (tt > 255) {
252 tt -= 255;
253 *op++ = 0;
254 }
255 *op++ = tt;
256 }
257 if (t >= 16) do {
258 COPY8(op, ii);
259 COPY8(op + 8, ii + 8);
260 op += 16;
261 ii += 16;
262 t -= 16;
263 } while (t >= 16);
264 if (t > 0) do {
265 *op++ = *ii++;
266 } while (--t > 0);
267 }
268
269 *op++ = M4_MARKER | 1;
270 *op++ = 0;
271 *op++ = 0;
272
273 *out_len = op - out;
274 return LZO_E_OK;
275}
276EXPORT_SYMBOL_GPL(lzo1x_1_compress);
277
278MODULE_LICENSE("GPL");
279MODULE_DESCRIPTION("LZO1X-1 Compressor");
280
