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18aecc2b CM |
1 | /* |
2 | * Copyright 2011 Tilera Corporation. All Rights Reserved. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public License | |
6 | * as published by the Free Software Foundation, version 2. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, but | |
9 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or | |
11 | * NON INFRINGEMENT. See the GNU General Public License for | |
12 | * more details. | |
13 | */ | |
14 | ||
15 | #include <linux/types.h> | |
16 | #include <linux/string.h> | |
17 | #include <linux/module.h> | |
18aecc2b CM |
18 | /* EXPORT_SYMBOL() is in arch/tile/lib/exports.c since this should be asm. */ |
19 | ||
20 | /* Must be 8 bytes in size. */ | |
c53c70a9 | 21 | #define op_t uint64_t |
18aecc2b | 22 | |
c53c70a9 CM |
23 | /* Threshold value for when to enter the unrolled loops. */ |
24 | #define OP_T_THRES 16 | |
25 | ||
26 | #if CHIP_L2_LINE_SIZE() != 64 | |
27 | #error "Assumes 64 byte line size" | |
18aecc2b CM |
28 | #endif |
29 | ||
30 | /* How many cache lines ahead should we prefetch? */ | |
c53c70a9 | 31 | #define PREFETCH_LINES_AHEAD 4 |
18aecc2b CM |
32 | |
33 | /* | |
34 | * Provide "base versions" of load and store for the normal code path. | |
35 | * The kernel provides other versions for userspace copies. | |
36 | */ | |
37 | #define ST(p, v) (*(p) = (v)) | |
38 | #define LD(p) (*(p)) | |
39 | ||
40 | #ifndef USERCOPY_FUNC | |
41 | #define ST1 ST | |
42 | #define ST2 ST | |
43 | #define ST4 ST | |
44 | #define ST8 ST | |
45 | #define LD1 LD | |
46 | #define LD2 LD | |
47 | #define LD4 LD | |
48 | #define LD8 LD | |
49 | #define RETVAL dstv | |
50 | void *memcpy(void *__restrict dstv, const void *__restrict srcv, size_t n) | |
51 | #else | |
52 | /* | |
53 | * Special kernel version will provide implementation of the LDn/STn | |
54 | * macros to return a count of uncopied bytes due to mm fault. | |
55 | */ | |
56 | #define RETVAL 0 | |
49cf78ef CM |
57 | int __attribute__((optimize("omit-frame-pointer"))) |
58 | USERCOPY_FUNC(void *__restrict dstv, const void *__restrict srcv, size_t n) | |
18aecc2b CM |
59 | #endif |
60 | { | |
61 | char *__restrict dst1 = (char *)dstv; | |
62 | const char *__restrict src1 = (const char *)srcv; | |
63 | const char *__restrict src1_end; | |
64 | const char *__restrict prefetch; | |
c53c70a9 CM |
65 | op_t *__restrict dst8; /* 8-byte pointer to destination memory. */ |
66 | op_t final; /* Final bytes to write to trailing word, if any */ | |
18aecc2b CM |
67 | long i; |
68 | ||
69 | if (n < 16) { | |
70 | for (; n; n--) | |
71 | ST1(dst1++, LD1(src1++)); | |
72 | return RETVAL; | |
73 | } | |
74 | ||
75 | /* | |
76 | * Locate the end of source memory we will copy. Don't | |
77 | * prefetch past this. | |
78 | */ | |
79 | src1_end = src1 + n - 1; | |
80 | ||
81 | /* Prefetch ahead a few cache lines, but not past the end. */ | |
82 | prefetch = src1; | |
83 | for (i = 0; i < PREFETCH_LINES_AHEAD; i++) { | |
84 | __insn_prefetch(prefetch); | |
85 | prefetch += CHIP_L2_LINE_SIZE(); | |
c53c70a9 | 86 | prefetch = (prefetch < src1_end) ? prefetch : src1; |
18aecc2b CM |
87 | } |
88 | ||
89 | /* Copy bytes until dst is word-aligned. */ | |
c53c70a9 | 90 | for (; (uintptr_t)dst1 & (sizeof(op_t) - 1); n--) |
18aecc2b CM |
91 | ST1(dst1++, LD1(src1++)); |
92 | ||
93 | /* 8-byte pointer to destination memory. */ | |
c53c70a9 CM |
94 | dst8 = (op_t *)dst1; |
95 | ||
96 | if (__builtin_expect((uintptr_t)src1 & (sizeof(op_t) - 1), 0)) { | |
97 | /* Unaligned copy. */ | |
98 | ||
99 | op_t tmp0 = 0, tmp1 = 0, tmp2, tmp3; | |
100 | const op_t *src8 = (const op_t *) ((uintptr_t)src1 & | |
101 | -sizeof(op_t)); | |
102 | const void *srci = (void *)src1; | |
103 | int m; | |
104 | ||
105 | m = (CHIP_L2_LINE_SIZE() << 2) - | |
106 | (((uintptr_t)dst8) & ((CHIP_L2_LINE_SIZE() << 2) - 1)); | |
107 | m = (n < m) ? n : m; | |
108 | m /= sizeof(op_t); | |
109 | ||
110 | /* Copy until 'dst' is cache-line-aligned. */ | |
111 | n -= (sizeof(op_t) * m); | |
112 | ||
113 | switch (m % 4) { | |
114 | case 0: | |
115 | if (__builtin_expect(!m, 0)) | |
116 | goto _M0; | |
117 | tmp1 = LD8(src8++); | |
118 | tmp2 = LD8(src8++); | |
119 | goto _8B3; | |
120 | case 2: | |
121 | m += 2; | |
122 | tmp3 = LD8(src8++); | |
123 | tmp0 = LD8(src8++); | |
124 | goto _8B1; | |
125 | case 3: | |
126 | m += 1; | |
127 | tmp2 = LD8(src8++); | |
128 | tmp3 = LD8(src8++); | |
129 | goto _8B2; | |
130 | case 1: | |
131 | m--; | |
132 | tmp0 = LD8(src8++); | |
133 | tmp1 = LD8(src8++); | |
134 | if (__builtin_expect(!m, 0)) | |
135 | goto _8B0; | |
136 | } | |
137 | ||
138 | do { | |
139 | tmp2 = LD8(src8++); | |
140 | tmp0 = __insn_dblalign(tmp0, tmp1, srci); | |
141 | ST8(dst8++, tmp0); | |
142 | _8B3: | |
143 | tmp3 = LD8(src8++); | |
144 | tmp1 = __insn_dblalign(tmp1, tmp2, srci); | |
145 | ST8(dst8++, tmp1); | |
146 | _8B2: | |
147 | tmp0 = LD8(src8++); | |
148 | tmp2 = __insn_dblalign(tmp2, tmp3, srci); | |
149 | ST8(dst8++, tmp2); | |
150 | _8B1: | |
151 | tmp1 = LD8(src8++); | |
152 | tmp3 = __insn_dblalign(tmp3, tmp0, srci); | |
153 | ST8(dst8++, tmp3); | |
154 | m -= 4; | |
155 | } while (m); | |
156 | ||
157 | _8B0: | |
158 | tmp0 = __insn_dblalign(tmp0, tmp1, srci); | |
159 | ST8(dst8++, tmp0); | |
160 | src8--; | |
161 | ||
162 | _M0: | |
163 | if (__builtin_expect(n >= CHIP_L2_LINE_SIZE(), 0)) { | |
164 | op_t tmp4, tmp5, tmp6, tmp7, tmp8; | |
165 | ||
166 | prefetch = ((const char *)src8) + | |
167 | CHIP_L2_LINE_SIZE() * PREFETCH_LINES_AHEAD; | |
168 | ||
169 | for (tmp0 = LD8(src8++); n >= CHIP_L2_LINE_SIZE(); | |
170 | n -= CHIP_L2_LINE_SIZE()) { | |
171 | /* Prefetch and advance to next line to | |
172 | prefetch, but don't go past the end. */ | |
173 | __insn_prefetch(prefetch); | |
174 | ||
175 | /* Make sure prefetch got scheduled | |
176 | earlier. */ | |
177 | __asm__ ("" : : : "memory"); | |
178 | ||
179 | prefetch += CHIP_L2_LINE_SIZE(); | |
180 | prefetch = (prefetch < src1_end) ? prefetch : | |
181 | (const char *) src8; | |
182 | ||
183 | tmp1 = LD8(src8++); | |
184 | tmp2 = LD8(src8++); | |
185 | tmp3 = LD8(src8++); | |
186 | tmp4 = LD8(src8++); | |
187 | tmp5 = LD8(src8++); | |
188 | tmp6 = LD8(src8++); | |
189 | tmp7 = LD8(src8++); | |
190 | tmp8 = LD8(src8++); | |
191 | ||
192 | tmp0 = __insn_dblalign(tmp0, tmp1, srci); | |
193 | tmp1 = __insn_dblalign(tmp1, tmp2, srci); | |
194 | tmp2 = __insn_dblalign(tmp2, tmp3, srci); | |
195 | tmp3 = __insn_dblalign(tmp3, tmp4, srci); | |
196 | tmp4 = __insn_dblalign(tmp4, tmp5, srci); | |
197 | tmp5 = __insn_dblalign(tmp5, tmp6, srci); | |
198 | tmp6 = __insn_dblalign(tmp6, tmp7, srci); | |
199 | tmp7 = __insn_dblalign(tmp7, tmp8, srci); | |
200 | ||
201 | __insn_wh64(dst8); | |
202 | ||
203 | ST8(dst8++, tmp0); | |
204 | ST8(dst8++, tmp1); | |
205 | ST8(dst8++, tmp2); | |
206 | ST8(dst8++, tmp3); | |
207 | ST8(dst8++, tmp4); | |
208 | ST8(dst8++, tmp5); | |
209 | ST8(dst8++, tmp6); | |
210 | ST8(dst8++, tmp7); | |
211 | ||
212 | tmp0 = tmp8; | |
213 | } | |
214 | src8--; | |
215 | } | |
216 | ||
217 | /* Copy the rest 8-byte chunks. */ | |
218 | if (n >= sizeof(op_t)) { | |
219 | tmp0 = LD8(src8++); | |
220 | for (; n >= sizeof(op_t); n -= sizeof(op_t)) { | |
221 | tmp1 = LD8(src8++); | |
222 | tmp0 = __insn_dblalign(tmp0, tmp1, srci); | |
223 | ST8(dst8++, tmp0); | |
224 | tmp0 = tmp1; | |
225 | } | |
226 | src8--; | |
18aecc2b CM |
227 | } |
228 | ||
229 | if (n == 0) | |
230 | return RETVAL; | |
231 | ||
c53c70a9 CM |
232 | tmp0 = LD8(src8++); |
233 | tmp1 = ((const char *)src8 <= src1_end) | |
234 | ? LD8((op_t *)src8) : 0; | |
235 | final = __insn_dblalign(tmp0, tmp1, srci); | |
18aecc2b | 236 | |
18aecc2b CM |
237 | } else { |
238 | /* Aligned copy. */ | |
239 | ||
c53c70a9 | 240 | const op_t *__restrict src8 = (const op_t *)src1; |
18aecc2b CM |
241 | |
242 | /* src8 and dst8 are both word-aligned. */ | |
243 | if (n >= CHIP_L2_LINE_SIZE()) { | |
244 | /* Copy until 'dst' is cache-line-aligned. */ | |
245 | for (; (uintptr_t)dst8 & (CHIP_L2_LINE_SIZE() - 1); | |
c53c70a9 | 246 | n -= sizeof(op_t)) |
18aecc2b CM |
247 | ST8(dst8++, LD8(src8++)); |
248 | ||
249 | for (; n >= CHIP_L2_LINE_SIZE(); ) { | |
c53c70a9 CM |
250 | op_t tmp0, tmp1, tmp2, tmp3; |
251 | op_t tmp4, tmp5, tmp6, tmp7; | |
18aecc2b CM |
252 | |
253 | /* | |
254 | * Prefetch and advance to next line | |
c53c70a9 CM |
255 | * to prefetch, but don't go past the |
256 | * end. | |
18aecc2b CM |
257 | */ |
258 | __insn_prefetch(prefetch); | |
c53c70a9 CM |
259 | |
260 | /* Make sure prefetch got scheduled | |
261 | earlier. */ | |
262 | __asm__ ("" : : : "memory"); | |
263 | ||
18aecc2b | 264 | prefetch += CHIP_L2_LINE_SIZE(); |
c53c70a9 | 265 | prefetch = (prefetch < src1_end) ? prefetch : |
18aecc2b CM |
266 | (const char *)src8; |
267 | ||
268 | /* | |
c53c70a9 CM |
269 | * Do all the loads before wh64. This |
270 | * is necessary if [src8, src8+7] and | |
271 | * [dst8, dst8+7] share the same cache | |
272 | * line and dst8 <= src8, as can be | |
273 | * the case when called from memmove, | |
274 | * or with code tested on x86 whose | |
275 | * memcpy always works with forward | |
276 | * copies. | |
18aecc2b | 277 | */ |
c53c70a9 CM |
278 | tmp0 = LD8(src8++); |
279 | tmp1 = LD8(src8++); | |
280 | tmp2 = LD8(src8++); | |
281 | tmp3 = LD8(src8++); | |
282 | tmp4 = LD8(src8++); | |
283 | tmp5 = LD8(src8++); | |
284 | tmp6 = LD8(src8++); | |
285 | tmp7 = LD8(src8++); | |
286 | ||
287 | /* wh64 and wait for tmp7 load completion. */ | |
288 | __asm__ ("move %0, %0; wh64 %1\n" | |
289 | : : "r"(tmp7), "r"(dst8)); | |
18aecc2b | 290 | |
c53c70a9 CM |
291 | ST8(dst8++, tmp0); |
292 | ST8(dst8++, tmp1); | |
293 | ST8(dst8++, tmp2); | |
294 | ST8(dst8++, tmp3); | |
295 | ST8(dst8++, tmp4); | |
296 | ST8(dst8++, tmp5); | |
297 | ST8(dst8++, tmp6); | |
298 | ST8(dst8++, tmp7); | |
299 | ||
300 | n -= CHIP_L2_LINE_SIZE(); | |
18aecc2b | 301 | } |
c53c70a9 CM |
302 | #if CHIP_L2_LINE_SIZE() != 64 |
303 | # error "Fix code that assumes particular L2 cache line size." | |
304 | #endif | |
18aecc2b CM |
305 | } |
306 | ||
c53c70a9 | 307 | for (; n >= sizeof(op_t); n -= sizeof(op_t)) |
18aecc2b CM |
308 | ST8(dst8++, LD8(src8++)); |
309 | ||
310 | if (__builtin_expect(n == 0, 1)) | |
311 | return RETVAL; | |
312 | ||
313 | final = LD8(src8); | |
314 | } | |
315 | ||
316 | /* n != 0 if we get here. Write out any trailing bytes. */ | |
317 | dst1 = (char *)dst8; | |
1efea40d | 318 | #ifndef __BIG_ENDIAN__ |
18aecc2b CM |
319 | if (n & 4) { |
320 | ST4((uint32_t *)dst1, final); | |
321 | dst1 += 4; | |
322 | final >>= 32; | |
323 | n &= 3; | |
324 | } | |
325 | if (n & 2) { | |
326 | ST2((uint16_t *)dst1, final); | |
327 | dst1 += 2; | |
328 | final >>= 16; | |
329 | n &= 1; | |
330 | } | |
331 | if (n) | |
332 | ST1((uint8_t *)dst1, final); | |
1efea40d CM |
333 | #else |
334 | if (n & 4) { | |
335 | ST4((uint32_t *)dst1, final >> 32); | |
336 | dst1 += 4; | |
337 | } | |
338 | else | |
339 | { | |
340 | final >>= 32; | |
341 | } | |
342 | if (n & 2) { | |
343 | ST2((uint16_t *)dst1, final >> 16); | |
344 | dst1 += 2; | |
345 | } | |
346 | else | |
347 | { | |
348 | final >>= 16; | |
349 | } | |
350 | if (n & 1) | |
351 | ST1((uint8_t *)dst1, final >> 8); | |
352 | #endif | |
18aecc2b CM |
353 | |
354 | return RETVAL; | |
355 | } | |
356 | ||
18aecc2b CM |
357 | #ifdef USERCOPY_FUNC |
358 | #undef ST1 | |
359 | #undef ST2 | |
360 | #undef ST4 | |
361 | #undef ST8 | |
362 | #undef LD1 | |
363 | #undef LD2 | |
364 | #undef LD4 | |
365 | #undef LD8 | |
366 | #undef USERCOPY_FUNC | |
367 | #endif |