1 | /* x86_64 cache info. |
2 | Copyright (C) 2003-2016 Free Software Foundation, Inc. |
3 | This file is part of the GNU C Library. |
4 | |
5 | The GNU C Library is free software; you can redistribute it and/or |
6 | modify it under the terms of the GNU Lesser General Public |
7 | License as published by the Free Software Foundation; either |
8 | version 2.1 of the License, or (at your option) any later version. |
9 | |
10 | The GNU C Library is distributed in the hope that it will be useful, |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
13 | Lesser General Public License for more details. |
14 | |
15 | You should have received a copy of the GNU Lesser General Public |
16 | License along with the GNU C Library; if not, see |
17 | <http://www.gnu.org/licenses/>. */ |
18 | |
19 | #include <assert.h> |
20 | #include <stdbool.h> |
21 | #include <stdlib.h> |
22 | #include <unistd.h> |
23 | #include <cpuid.h> |
24 | #include <init-arch.h> |
25 | |
26 | #define is_intel GLRO(dl_x86_cpu_features).kind == arch_kind_intel |
27 | #define is_amd GLRO(dl_x86_cpu_features).kind == arch_kind_amd |
28 | #define max_cpuid GLRO(dl_x86_cpu_features).max_cpuid |
29 | |
30 | static const struct intel_02_cache_info |
31 | { |
32 | unsigned char idx; |
33 | unsigned char assoc; |
34 | unsigned char linesize; |
35 | unsigned char rel_name; |
36 | unsigned int size; |
37 | } intel_02_known [] = |
38 | { |
39 | #define M(sc) ((sc) - _SC_LEVEL1_ICACHE_SIZE) |
40 | { 0x06, 4, 32, M(_SC_LEVEL1_ICACHE_SIZE), 8192 }, |
41 | { 0x08, 4, 32, M(_SC_LEVEL1_ICACHE_SIZE), 16384 }, |
42 | { 0x09, 4, 32, M(_SC_LEVEL1_ICACHE_SIZE), 32768 }, |
43 | { 0x0a, 2, 32, M(_SC_LEVEL1_DCACHE_SIZE), 8192 }, |
44 | { 0x0c, 4, 32, M(_SC_LEVEL1_DCACHE_SIZE), 16384 }, |
45 | { 0x0d, 4, 64, M(_SC_LEVEL1_DCACHE_SIZE), 16384 }, |
46 | { 0x0e, 6, 64, M(_SC_LEVEL1_DCACHE_SIZE), 24576 }, |
47 | { 0x21, 8, 64, M(_SC_LEVEL2_CACHE_SIZE), 262144 }, |
48 | { 0x22, 4, 64, M(_SC_LEVEL3_CACHE_SIZE), 524288 }, |
49 | { 0x23, 8, 64, M(_SC_LEVEL3_CACHE_SIZE), 1048576 }, |
50 | { 0x25, 8, 64, M(_SC_LEVEL3_CACHE_SIZE), 2097152 }, |
51 | { 0x29, 8, 64, M(_SC_LEVEL3_CACHE_SIZE), 4194304 }, |
52 | { 0x2c, 8, 64, M(_SC_LEVEL1_DCACHE_SIZE), 32768 }, |
53 | { 0x30, 8, 64, M(_SC_LEVEL1_ICACHE_SIZE), 32768 }, |
54 | { 0x39, 4, 64, M(_SC_LEVEL2_CACHE_SIZE), 131072 }, |
55 | { 0x3a, 6, 64, M(_SC_LEVEL2_CACHE_SIZE), 196608 }, |
56 | { 0x3b, 2, 64, M(_SC_LEVEL2_CACHE_SIZE), 131072 }, |
57 | { 0x3c, 4, 64, M(_SC_LEVEL2_CACHE_SIZE), 262144 }, |
58 | { 0x3d, 6, 64, M(_SC_LEVEL2_CACHE_SIZE), 393216 }, |
59 | { 0x3e, 4, 64, M(_SC_LEVEL2_CACHE_SIZE), 524288 }, |
60 | { 0x3f, 2, 64, M(_SC_LEVEL2_CACHE_SIZE), 262144 }, |
61 | { 0x41, 4, 32, M(_SC_LEVEL2_CACHE_SIZE), 131072 }, |
62 | { 0x42, 4, 32, M(_SC_LEVEL2_CACHE_SIZE), 262144 }, |
63 | { 0x43, 4, 32, M(_SC_LEVEL2_CACHE_SIZE), 524288 }, |
64 | { 0x44, 4, 32, M(_SC_LEVEL2_CACHE_SIZE), 1048576 }, |
65 | { 0x45, 4, 32, M(_SC_LEVEL2_CACHE_SIZE), 2097152 }, |
66 | { 0x46, 4, 64, M(_SC_LEVEL3_CACHE_SIZE), 4194304 }, |
67 | { 0x47, 8, 64, M(_SC_LEVEL3_CACHE_SIZE), 8388608 }, |
68 | { 0x48, 12, 64, M(_SC_LEVEL2_CACHE_SIZE), 3145728 }, |
69 | { 0x49, 16, 64, M(_SC_LEVEL2_CACHE_SIZE), 4194304 }, |
70 | { 0x4a, 12, 64, M(_SC_LEVEL3_CACHE_SIZE), 6291456 }, |
71 | { 0x4b, 16, 64, M(_SC_LEVEL3_CACHE_SIZE), 8388608 }, |
72 | { 0x4c, 12, 64, M(_SC_LEVEL3_CACHE_SIZE), 12582912 }, |
73 | { 0x4d, 16, 64, M(_SC_LEVEL3_CACHE_SIZE), 16777216 }, |
74 | { 0x4e, 24, 64, M(_SC_LEVEL2_CACHE_SIZE), 6291456 }, |
75 | { 0x60, 8, 64, M(_SC_LEVEL1_DCACHE_SIZE), 16384 }, |
76 | { 0x66, 4, 64, M(_SC_LEVEL1_DCACHE_SIZE), 8192 }, |
77 | { 0x67, 4, 64, M(_SC_LEVEL1_DCACHE_SIZE), 16384 }, |
78 | { 0x68, 4, 64, M(_SC_LEVEL1_DCACHE_SIZE), 32768 }, |
79 | { 0x78, 8, 64, M(_SC_LEVEL2_CACHE_SIZE), 1048576 }, |
80 | { 0x79, 8, 64, M(_SC_LEVEL2_CACHE_SIZE), 131072 }, |
81 | { 0x7a, 8, 64, M(_SC_LEVEL2_CACHE_SIZE), 262144 }, |
82 | { 0x7b, 8, 64, M(_SC_LEVEL2_CACHE_SIZE), 524288 }, |
83 | { 0x7c, 8, 64, M(_SC_LEVEL2_CACHE_SIZE), 1048576 }, |
84 | { 0x7d, 8, 64, M(_SC_LEVEL2_CACHE_SIZE), 2097152 }, |
85 | { 0x7f, 2, 64, M(_SC_LEVEL2_CACHE_SIZE), 524288 }, |
86 | { 0x80, 8, 64, M(_SC_LEVEL2_CACHE_SIZE), 524288 }, |
87 | { 0x82, 8, 32, M(_SC_LEVEL2_CACHE_SIZE), 262144 }, |
88 | { 0x83, 8, 32, M(_SC_LEVEL2_CACHE_SIZE), 524288 }, |
89 | { 0x84, 8, 32, M(_SC_LEVEL2_CACHE_SIZE), 1048576 }, |
90 | { 0x85, 8, 32, M(_SC_LEVEL2_CACHE_SIZE), 2097152 }, |
91 | { 0x86, 4, 64, M(_SC_LEVEL2_CACHE_SIZE), 524288 }, |
92 | { 0x87, 8, 64, M(_SC_LEVEL2_CACHE_SIZE), 1048576 }, |
93 | { 0xd0, 4, 64, M(_SC_LEVEL3_CACHE_SIZE), 524288 }, |
94 | { 0xd1, 4, 64, M(_SC_LEVEL3_CACHE_SIZE), 1048576 }, |
95 | { 0xd2, 4, 64, M(_SC_LEVEL3_CACHE_SIZE), 2097152 }, |
96 | { 0xd6, 8, 64, M(_SC_LEVEL3_CACHE_SIZE), 1048576 }, |
97 | { 0xd7, 8, 64, M(_SC_LEVEL3_CACHE_SIZE), 2097152 }, |
98 | { 0xd8, 8, 64, M(_SC_LEVEL3_CACHE_SIZE), 4194304 }, |
99 | { 0xdc, 12, 64, M(_SC_LEVEL3_CACHE_SIZE), 2097152 }, |
100 | { 0xdd, 12, 64, M(_SC_LEVEL3_CACHE_SIZE), 4194304 }, |
101 | { 0xde, 12, 64, M(_SC_LEVEL3_CACHE_SIZE), 8388608 }, |
102 | { 0xe2, 16, 64, M(_SC_LEVEL3_CACHE_SIZE), 2097152 }, |
103 | { 0xe3, 16, 64, M(_SC_LEVEL3_CACHE_SIZE), 4194304 }, |
104 | { 0xe4, 16, 64, M(_SC_LEVEL3_CACHE_SIZE), 8388608 }, |
105 | { 0xea, 24, 64, M(_SC_LEVEL3_CACHE_SIZE), 12582912 }, |
106 | { 0xeb, 24, 64, M(_SC_LEVEL3_CACHE_SIZE), 18874368 }, |
107 | { 0xec, 24, 64, M(_SC_LEVEL3_CACHE_SIZE), 25165824 }, |
108 | }; |
109 | |
110 | #define nintel_02_known (sizeof (intel_02_known) / sizeof (intel_02_known [0])) |
111 | |
112 | static int |
113 | intel_02_known_compare (const void *p1, const void *p2) |
114 | { |
115 | const struct intel_02_cache_info *i1; |
116 | const struct intel_02_cache_info *i2; |
117 | |
118 | i1 = (const struct intel_02_cache_info *) p1; |
119 | i2 = (const struct intel_02_cache_info *) p2; |
120 | |
121 | if (i1->idx == i2->idx) |
122 | return 0; |
123 | |
124 | return i1->idx < i2->idx ? -1 : 1; |
125 | } |
126 | |
127 | |
128 | static long int |
129 | __attribute__ ((noinline)) |
130 | intel_check_word (int name, unsigned int value, bool *has_level_2, |
131 | bool *no_level_2_or_3) |
132 | { |
133 | if ((value & 0x80000000) != 0) |
134 | /* The register value is reserved. */ |
135 | return 0; |
136 | |
137 | /* Fold the name. The _SC_ constants are always in the order SIZE, |
138 | ASSOC, LINESIZE. */ |
139 | int folded_rel_name = (M(name) / 3) * 3; |
140 | |
141 | while (value != 0) |
142 | { |
143 | unsigned int byte = value & 0xff; |
144 | |
145 | if (byte == 0x40) |
146 | { |
147 | *no_level_2_or_3 = true; |
148 | |
149 | if (folded_rel_name == M(_SC_LEVEL3_CACHE_SIZE)) |
150 | /* No need to look further. */ |
151 | break; |
152 | } |
153 | else if (byte == 0xff) |
154 | { |
155 | /* CPUID leaf 0x4 contains all the information. We need to |
156 | iterate over it. */ |
157 | unsigned int eax; |
158 | unsigned int ebx; |
159 | unsigned int ecx; |
160 | unsigned int edx; |
161 | |
162 | unsigned int round = 0; |
163 | while (1) |
164 | { |
165 | __cpuid_count (4, round, eax, ebx, ecx, edx); |
166 | |
167 | enum { null = 0, data = 1, inst = 2, uni = 3 } type = eax & 0x1f; |
168 | if (type == null) |
169 | /* That was the end. */ |
170 | break; |
171 | |
172 | unsigned int level = (eax >> 5) & 0x7; |
173 | |
174 | if ((level == 1 && type == data |
175 | && folded_rel_name == M(_SC_LEVEL1_DCACHE_SIZE)) |
176 | || (level == 1 && type == inst |
177 | && folded_rel_name == M(_SC_LEVEL1_ICACHE_SIZE)) |
178 | || (level == 2 && folded_rel_name == M(_SC_LEVEL2_CACHE_SIZE)) |
179 | || (level == 3 && folded_rel_name == M(_SC_LEVEL3_CACHE_SIZE)) |
180 | || (level == 4 && folded_rel_name == M(_SC_LEVEL4_CACHE_SIZE))) |
181 | { |
182 | unsigned int offset = M(name) - folded_rel_name; |
183 | |
184 | if (offset == 0) |
185 | /* Cache size. */ |
186 | return (((ebx >> 22) + 1) |
187 | * (((ebx >> 12) & 0x3ff) + 1) |
188 | * ((ebx & 0xfff) + 1) |
189 | * (ecx + 1)); |
190 | if (offset == 1) |
191 | return (ebx >> 22) + 1; |
192 | |
193 | assert (offset == 2); |
194 | return (ebx & 0xfff) + 1; |
195 | } |
196 | |
197 | ++round; |
198 | } |
199 | /* There is no other cache information anywhere else. */ |
200 | break; |
201 | } |
202 | else |
203 | { |
204 | if (byte == 0x49 && folded_rel_name == M(_SC_LEVEL3_CACHE_SIZE)) |
205 | { |
206 | /* Intel reused this value. For family 15, model 6 it |
207 | specifies the 3rd level cache. Otherwise the 2nd |
208 | level cache. */ |
209 | unsigned int family = GLRO(dl_x86_cpu_features).family; |
210 | unsigned int model = GLRO(dl_x86_cpu_features).model; |
211 | |
212 | if (family == 15 && model == 6) |
213 | { |
214 | /* The level 3 cache is encoded for this model like |
215 | the level 2 cache is for other models. Pretend |
216 | the caller asked for the level 2 cache. */ |
217 | name = (_SC_LEVEL2_CACHE_SIZE |
218 | + (name - _SC_LEVEL3_CACHE_SIZE)); |
219 | folded_rel_name = M(_SC_LEVEL2_CACHE_SIZE); |
220 | } |
221 | } |
222 | |
223 | struct intel_02_cache_info *found; |
224 | struct intel_02_cache_info search; |
225 | |
226 | search.idx = byte; |
227 | found = bsearch (&search, intel_02_known, nintel_02_known, |
228 | sizeof (intel_02_known[0]), intel_02_known_compare); |
229 | if (found != NULL) |
230 | { |
231 | if (found->rel_name == folded_rel_name) |
232 | { |
233 | unsigned int offset = M(name) - folded_rel_name; |
234 | |
235 | if (offset == 0) |
236 | /* Cache size. */ |
237 | return found->size; |
238 | if (offset == 1) |
239 | return found->assoc; |
240 | |
241 | assert (offset == 2); |
242 | return found->linesize; |
243 | } |
244 | |
245 | if (found->rel_name == M(_SC_LEVEL2_CACHE_SIZE)) |
246 | *has_level_2 = true; |
247 | } |
248 | } |
249 | |
250 | /* Next byte for the next round. */ |
251 | value >>= 8; |
252 | } |
253 | |
254 | /* Nothing found. */ |
255 | return 0; |
256 | } |
257 | |
258 | |
259 | static long int __attribute__ ((noinline)) |
260 | handle_intel (int name, unsigned int maxidx) |
261 | { |
262 | assert (maxidx >= 2); |
263 | |
264 | /* OK, we can use the CPUID instruction to get all info about the |
265 | caches. */ |
266 | unsigned int cnt = 0; |
267 | unsigned int max = 1; |
268 | long int result = 0; |
269 | bool no_level_2_or_3 = false; |
270 | bool has_level_2 = false; |
271 | |
272 | while (cnt++ < max) |
273 | { |
274 | unsigned int eax; |
275 | unsigned int ebx; |
276 | unsigned int ecx; |
277 | unsigned int edx; |
278 | __cpuid (2, eax, ebx, ecx, edx); |
279 | |
280 | /* The low byte of EAX in the first round contain the number of |
281 | rounds we have to make. At least one, the one we are already |
282 | doing. */ |
283 | if (cnt == 1) |
284 | { |
285 | max = eax & 0xff; |
286 | eax &= 0xffffff00; |
287 | } |
288 | |
289 | /* Process the individual registers' value. */ |
290 | result = intel_check_word (name, eax, &has_level_2, &no_level_2_or_3); |
291 | if (result != 0) |
292 | return result; |
293 | |
294 | result = intel_check_word (name, ebx, &has_level_2, &no_level_2_or_3); |
295 | if (result != 0) |
296 | return result; |
297 | |
298 | result = intel_check_word (name, ecx, &has_level_2, &no_level_2_or_3); |
299 | if (result != 0) |
300 | return result; |
301 | |
302 | result = intel_check_word (name, edx, &has_level_2, &no_level_2_or_3); |
303 | if (result != 0) |
304 | return result; |
305 | } |
306 | |
307 | if (name >= _SC_LEVEL2_CACHE_SIZE && name <= _SC_LEVEL3_CACHE_LINESIZE |
308 | && no_level_2_or_3) |
309 | return -1; |
310 | |
311 | return 0; |
312 | } |
313 | |
314 | |
315 | static long int __attribute__ ((noinline)) |
316 | handle_amd (int name) |
317 | { |
318 | unsigned int eax; |
319 | unsigned int ebx; |
320 | unsigned int ecx; |
321 | unsigned int edx; |
322 | __cpuid (0x80000000, eax, ebx, ecx, edx); |
323 | |
324 | /* No level 4 cache (yet). */ |
325 | if (name > _SC_LEVEL3_CACHE_LINESIZE) |
326 | return 0; |
327 | |
328 | unsigned int fn = 0x80000005 + (name >= _SC_LEVEL2_CACHE_SIZE); |
329 | if (eax < fn) |
330 | return 0; |
331 | |
332 | __cpuid (fn, eax, ebx, ecx, edx); |
333 | |
334 | if (name < _SC_LEVEL1_DCACHE_SIZE) |
335 | { |
336 | name += _SC_LEVEL1_DCACHE_SIZE - _SC_LEVEL1_ICACHE_SIZE; |
337 | ecx = edx; |
338 | } |
339 | |
340 | switch (name) |
341 | { |
342 | case _SC_LEVEL1_DCACHE_SIZE: |
343 | return (ecx >> 14) & 0x3fc00; |
344 | |
345 | case _SC_LEVEL1_DCACHE_ASSOC: |
346 | ecx >>= 16; |
347 | if ((ecx & 0xff) == 0xff) |
348 | /* Fully associative. */ |
349 | return (ecx << 2) & 0x3fc00; |
350 | return ecx & 0xff; |
351 | |
352 | case _SC_LEVEL1_DCACHE_LINESIZE: |
353 | return ecx & 0xff; |
354 | |
355 | case _SC_LEVEL2_CACHE_SIZE: |
356 | return (ecx & 0xf000) == 0 ? 0 : (ecx >> 6) & 0x3fffc00; |
357 | |
358 | case _SC_LEVEL2_CACHE_ASSOC: |
359 | switch ((ecx >> 12) & 0xf) |
360 | { |
361 | case 0: |
362 | case 1: |
363 | case 2: |
364 | case 4: |
365 | return (ecx >> 12) & 0xf; |
366 | case 6: |
367 | return 8; |
368 | case 8: |
369 | return 16; |
370 | case 10: |
371 | return 32; |
372 | case 11: |
373 | return 48; |
374 | case 12: |
375 | return 64; |
376 | case 13: |
377 | return 96; |
378 | case 14: |
379 | return 128; |
380 | case 15: |
381 | return ((ecx >> 6) & 0x3fffc00) / (ecx & 0xff); |
382 | default: |
383 | return 0; |
384 | } |
385 | /* NOTREACHED */ |
386 | |
387 | case _SC_LEVEL2_CACHE_LINESIZE: |
388 | return (ecx & 0xf000) == 0 ? 0 : ecx & 0xff; |
389 | |
390 | case _SC_LEVEL3_CACHE_SIZE: |
391 | return (edx & 0xf000) == 0 ? 0 : (edx & 0x3ffc0000) << 1; |
392 | |
393 | case _SC_LEVEL3_CACHE_ASSOC: |
394 | switch ((edx >> 12) & 0xf) |
395 | { |
396 | case 0: |
397 | case 1: |
398 | case 2: |
399 | case 4: |
400 | return (edx >> 12) & 0xf; |
401 | case 6: |
402 | return 8; |
403 | case 8: |
404 | return 16; |
405 | case 10: |
406 | return 32; |
407 | case 11: |
408 | return 48; |
409 | case 12: |
410 | return 64; |
411 | case 13: |
412 | return 96; |
413 | case 14: |
414 | return 128; |
415 | case 15: |
416 | return ((edx & 0x3ffc0000) << 1) / (edx & 0xff); |
417 | default: |
418 | return 0; |
419 | } |
420 | /* NOTREACHED */ |
421 | |
422 | case _SC_LEVEL3_CACHE_LINESIZE: |
423 | return (edx & 0xf000) == 0 ? 0 : edx & 0xff; |
424 | |
425 | default: |
426 | assert (! "cannot happen" ); |
427 | } |
428 | return -1; |
429 | } |
430 | |
431 | |
432 | /* Get the value of the system variable NAME. */ |
433 | long int |
434 | attribute_hidden |
435 | __cache_sysconf (int name) |
436 | { |
437 | if (is_intel) |
438 | return handle_intel (name, max_cpuid); |
439 | |
440 | if (is_amd) |
441 | return handle_amd (name); |
442 | |
443 | // XXX Fill in more vendors. |
444 | |
445 | /* CPU not known, we have no information. */ |
446 | return 0; |
447 | } |
448 | |
449 | |
450 | /* Data cache size for use in memory and string routines, typically |
451 | L1 size, rounded to multiple of 256 bytes. */ |
452 | long int __x86_data_cache_size_half attribute_hidden = 32 * 1024 / 2; |
453 | long int __x86_data_cache_size attribute_hidden = 32 * 1024; |
454 | /* Similar to __x86_data_cache_size_half, but not rounded. */ |
455 | long int __x86_raw_data_cache_size_half attribute_hidden = 32 * 1024 / 2; |
456 | /* Similar to __x86_data_cache_size, but not rounded. */ |
457 | long int __x86_raw_data_cache_size attribute_hidden = 32 * 1024; |
458 | /* Shared cache size for use in memory and string routines, typically |
459 | L2 or L3 size, rounded to multiple of 256 bytes. */ |
460 | long int __x86_shared_cache_size_half attribute_hidden = 1024 * 1024 / 2; |
461 | long int __x86_shared_cache_size attribute_hidden = 1024 * 1024; |
462 | /* Similar to __x86_shared_cache_size_half, but not rounded. */ |
463 | long int __x86_raw_shared_cache_size_half attribute_hidden = 1024 * 1024 / 2; |
464 | /* Similar to __x86_shared_cache_size, but not rounded. */ |
465 | long int __x86_raw_shared_cache_size attribute_hidden = 1024 * 1024; |
466 | |
467 | /* Threshold to use non temporal store. */ |
468 | long int __x86_shared_non_temporal_threshold attribute_hidden; |
469 | |
470 | #ifndef DISABLE_PREFETCHW |
471 | /* PREFETCHW support flag for use in memory and string routines. */ |
472 | int __x86_prefetchw attribute_hidden; |
473 | #endif |
474 | |
475 | |
476 | static void |
477 | __attribute__((constructor)) |
478 | init_cacheinfo (void) |
479 | { |
480 | /* Find out what brand of processor. */ |
481 | unsigned int eax; |
482 | unsigned int ebx; |
483 | unsigned int ecx; |
484 | unsigned int edx; |
485 | int max_cpuid_ex; |
486 | long int data = -1; |
487 | long int shared = -1; |
488 | unsigned int level; |
489 | unsigned int threads = 0; |
490 | |
491 | if (is_intel) |
492 | { |
493 | data = handle_intel (_SC_LEVEL1_DCACHE_SIZE, max_cpuid); |
494 | |
495 | long int core = handle_intel (_SC_LEVEL2_CACHE_SIZE, max_cpuid); |
496 | bool inclusive_cache = true; |
497 | |
498 | /* Try L3 first. */ |
499 | level = 3; |
500 | shared = handle_intel (_SC_LEVEL3_CACHE_SIZE, max_cpuid); |
501 | |
502 | /* Number of logical processors sharing L2 cache. */ |
503 | int threads_l2; |
504 | |
505 | /* Number of logical processors sharing L3 cache. */ |
506 | int threads_l3; |
507 | |
508 | if (shared <= 0) |
509 | { |
510 | /* Try L2 otherwise. */ |
511 | level = 2; |
512 | shared = core; |
513 | threads_l2 = 0; |
514 | threads_l3 = -1; |
515 | } |
516 | else |
517 | { |
518 | threads_l2 = 0; |
519 | threads_l3 = 0; |
520 | } |
521 | |
522 | /* A value of 0 for the HTT bit indicates there is only a single |
523 | logical processor. */ |
524 | if (HAS_CPU_FEATURE (HTT)) |
525 | { |
526 | /* Figure out the number of logical threads that share the |
527 | highest cache level. */ |
528 | if (max_cpuid >= 4) |
529 | { |
530 | unsigned int family = GLRO(dl_x86_cpu_features).family; |
531 | unsigned int model = GLRO(dl_x86_cpu_features).model; |
532 | |
533 | int i = 0; |
534 | |
535 | /* Query until cache level 2 and 3 are enumerated. */ |
536 | int check = 0x1 | (threads_l3 == 0) << 1; |
537 | do |
538 | { |
539 | __cpuid_count (4, i++, eax, ebx, ecx, edx); |
540 | |
541 | /* There seems to be a bug in at least some Pentium Ds |
542 | which sometimes fail to iterate all cache parameters. |
543 | Do not loop indefinitely here, stop in this case and |
544 | assume there is no such information. */ |
545 | if ((eax & 0x1f) == 0) |
546 | goto intel_bug_no_cache_info; |
547 | |
548 | switch ((eax >> 5) & 0x7) |
549 | { |
550 | default: |
551 | break; |
552 | case 2: |
553 | if ((check & 0x1)) |
554 | { |
555 | /* Get maximum number of logical processors |
556 | sharing L2 cache. */ |
557 | threads_l2 = (eax >> 14) & 0x3ff; |
558 | check &= ~0x1; |
559 | } |
560 | break; |
561 | case 3: |
562 | if ((check & (0x1 << 1))) |
563 | { |
564 | /* Get maximum number of logical processors |
565 | sharing L3 cache. */ |
566 | threads_l3 = (eax >> 14) & 0x3ff; |
567 | |
568 | /* Check if L2 and L3 caches are inclusive. */ |
569 | inclusive_cache = (edx & 0x2) != 0; |
570 | check &= ~(0x1 << 1); |
571 | } |
572 | break; |
573 | } |
574 | } |
575 | while (check); |
576 | |
577 | /* If max_cpuid >= 11, THREADS_L2/THREADS_L3 are the maximum |
578 | numbers of addressable IDs for logical processors sharing |
579 | the cache, instead of the maximum number of threads |
580 | sharing the cache. */ |
581 | if (max_cpuid >= 11) |
582 | { |
583 | /* Find the number of logical processors shipped in |
584 | one core and apply count mask. */ |
585 | i = 0; |
586 | |
587 | /* Count SMT only if there is L3 cache. Always count |
588 | core if there is no L3 cache. */ |
589 | int count = ((threads_l2 > 0 && level == 3) |
590 | | ((threads_l3 > 0 |
591 | || (threads_l2 > 0 && level == 2)) << 1)); |
592 | |
593 | while (count) |
594 | { |
595 | __cpuid_count (11, i++, eax, ebx, ecx, edx); |
596 | |
597 | int shipped = ebx & 0xff; |
598 | int type = ecx & 0xff00; |
599 | if (shipped == 0 || type == 0) |
600 | break; |
601 | else if (type == 0x100) |
602 | { |
603 | /* Count SMT. */ |
604 | if ((count & 0x1)) |
605 | { |
606 | int count_mask; |
607 | |
608 | /* Compute count mask. */ |
609 | asm ("bsr %1, %0" |
610 | : "=r" (count_mask) : "g" (threads_l2)); |
611 | count_mask = ~(-1 << (count_mask + 1)); |
612 | threads_l2 = (shipped - 1) & count_mask; |
613 | count &= ~0x1; |
614 | } |
615 | } |
616 | else if (type == 0x200) |
617 | { |
618 | /* Count core. */ |
619 | if ((count & (0x1 << 1))) |
620 | { |
621 | int count_mask; |
622 | int threads_core |
623 | = (level == 2 ? threads_l2 : threads_l3); |
624 | |
625 | /* Compute count mask. */ |
626 | asm ("bsr %1, %0" |
627 | : "=r" (count_mask) : "g" (threads_core)); |
628 | count_mask = ~(-1 << (count_mask + 1)); |
629 | threads_core = (shipped - 1) & count_mask; |
630 | if (level == 2) |
631 | threads_l2 = threads_core; |
632 | else |
633 | threads_l3 = threads_core; |
634 | count &= ~(0x1 << 1); |
635 | } |
636 | } |
637 | } |
638 | } |
639 | if (threads_l2 > 0) |
640 | threads_l2 += 1; |
641 | if (threads_l3 > 0) |
642 | threads_l3 += 1; |
643 | if (level == 2) |
644 | { |
645 | if (threads_l2) |
646 | { |
647 | threads = threads_l2; |
648 | if (threads > 2 && family == 6) |
649 | switch (model) |
650 | { |
651 | case 0x37: |
652 | case 0x4a: |
653 | case 0x4d: |
654 | case 0x5a: |
655 | case 0x5d: |
656 | /* Silvermont has L2 cache shared by 2 cores. */ |
657 | threads = 2; |
658 | break; |
659 | default: |
660 | break; |
661 | } |
662 | } |
663 | } |
664 | else if (threads_l3) |
665 | threads = threads_l3; |
666 | } |
667 | else |
668 | { |
669 | intel_bug_no_cache_info: |
670 | /* Assume that all logical threads share the highest cache |
671 | level. */ |
672 | |
673 | threads |
674 | = ((GLRO(dl_x86_cpu_features).cpuid[COMMON_CPUID_INDEX_1].ebx |
675 | >> 16) & 0xff); |
676 | } |
677 | |
678 | /* Cap usage of highest cache level to the number of supported |
679 | threads. */ |
680 | if (shared > 0 && threads > 0) |
681 | shared /= threads; |
682 | } |
683 | |
684 | /* Account for non-inclusive L2 and L3 caches. */ |
685 | if (!inclusive_cache) |
686 | { |
687 | if (threads_l2 > 0) |
688 | core /= threads_l2; |
689 | shared += core; |
690 | } |
691 | } |
692 | /* This spells out "AuthenticAMD". */ |
693 | else if (is_amd) |
694 | { |
695 | data = handle_amd (_SC_LEVEL1_DCACHE_SIZE); |
696 | long int core = handle_amd (_SC_LEVEL2_CACHE_SIZE); |
697 | shared = handle_amd (_SC_LEVEL3_CACHE_SIZE); |
698 | |
699 | /* Get maximum extended function. */ |
700 | __cpuid (0x80000000, max_cpuid_ex, ebx, ecx, edx); |
701 | |
702 | if (shared <= 0) |
703 | /* No shared L3 cache. All we have is the L2 cache. */ |
704 | shared = core; |
705 | else |
706 | { |
707 | /* Figure out the number of logical threads that share L3. */ |
708 | if (max_cpuid_ex >= 0x80000008) |
709 | { |
710 | /* Get width of APIC ID. */ |
711 | __cpuid (0x80000008, max_cpuid_ex, ebx, ecx, edx); |
712 | threads = 1 << ((ecx >> 12) & 0x0f); |
713 | } |
714 | |
715 | if (threads == 0) |
716 | { |
717 | /* If APIC ID width is not available, use logical |
718 | processor count. */ |
719 | __cpuid (0x00000001, max_cpuid_ex, ebx, ecx, edx); |
720 | |
721 | if ((edx & (1 << 28)) != 0) |
722 | threads = (ebx >> 16) & 0xff; |
723 | } |
724 | |
725 | /* Cap usage of highest cache level to the number of |
726 | supported threads. */ |
727 | if (threads > 0) |
728 | shared /= threads; |
729 | |
730 | /* Account for exclusive L2 and L3 caches. */ |
731 | shared += core; |
732 | } |
733 | |
734 | #ifndef DISABLE_PREFETCHW |
735 | if (max_cpuid_ex >= 0x80000001) |
736 | { |
737 | __cpuid (0x80000001, eax, ebx, ecx, edx); |
738 | /* PREFETCHW || 3DNow! */ |
739 | if ((ecx & 0x100) || (edx & 0x80000000)) |
740 | __x86_prefetchw = -1; |
741 | } |
742 | #endif |
743 | } |
744 | |
745 | if (data > 0) |
746 | { |
747 | __x86_raw_data_cache_size_half = data / 2; |
748 | __x86_raw_data_cache_size = data; |
749 | /* Round data cache size to multiple of 256 bytes. */ |
750 | data = data & ~255L; |
751 | __x86_data_cache_size_half = data / 2; |
752 | __x86_data_cache_size = data; |
753 | } |
754 | |
755 | if (shared > 0) |
756 | { |
757 | __x86_raw_shared_cache_size_half = shared / 2; |
758 | __x86_raw_shared_cache_size = shared; |
759 | /* Round shared cache size to multiple of 256 bytes. */ |
760 | shared = shared & ~255L; |
761 | __x86_shared_cache_size_half = shared / 2; |
762 | __x86_shared_cache_size = shared; |
763 | } |
764 | |
765 | /* The large memcpy micro benchmark in glibc shows that 6 times of |
766 | shared cache size is the approximate value above which non-temporal |
767 | store becomes faster. */ |
768 | __x86_shared_non_temporal_threshold = __x86_shared_cache_size * 6; |
769 | } |
770 | |