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| 1 // Copyright 2013 the V8 project authors. All rights reserved. | |
| 2 // Use of this source code is governed by a BSD-style license that can be | |
| 3 // found in the LICENSE file. | |
| 4 | |
| 5 #include "src/cpu.h" | |
| 6 | |
| 7 #if V8_LIBC_MSVCRT | |
| 8 #include <intrin.h> // __cpuid() | |
| 9 #endif | |
| 10 #if V8_OS_POSIX | |
| 11 #include <unistd.h> // sysconf() | |
| 12 #endif | |
| 13 #if V8_OS_QNX | |
| 14 #include <sys/syspage.h> // cpuinfo | |
| 15 #endif | |
| 16 | |
| 17 #include <ctype.h> | |
| 18 #include <limits.h> | |
| 19 #include <stdio.h> | |
| 20 #include <stdlib.h> | |
| 21 #include <string.h> | |
| 22 #include <algorithm> | |
| 23 | |
| 24 #include "src/checks.h" | |
| 25 #if V8_OS_WIN | |
| 26 #include "src/base/win32-headers.h" // NOLINT | |
| 27 #endif | |
| 28 | |
| 29 namespace v8 { | |
| 30 namespace internal { | |
| 31 | |
| 32 #if V8_HOST_ARCH_IA32 || V8_HOST_ARCH_X64 | |
| 33 | |
| 34 // Define __cpuid() for non-MSVC libraries. | |
| 35 #if !V8_LIBC_MSVCRT | |
| 36 | |
| 37 static V8_INLINE void __cpuid(int cpu_info[4], int info_type) { | |
| 38 #if defined(__i386__) && defined(__pic__) | |
| 39 // Make sure to preserve ebx, which contains the pointer | |
| 40 // to the GOT in case we're generating PIC. | |
| 41 __asm__ volatile ( | |
| 42 "mov %%ebx, %%edi\n\t" | |
| 43 "cpuid\n\t" | |
| 44 "xchg %%edi, %%ebx\n\t" | |
| 45 : "=a"(cpu_info[0]), "=D"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3]) | |
| 46 : "a"(info_type) | |
| 47 ); | |
| 48 #else | |
| 49 __asm__ volatile ( | |
| 50 "cpuid \n\t" | |
| 51 : "=a"(cpu_info[0]), "=b"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3]) | |
| 52 : "a"(info_type) | |
| 53 ); | |
| 54 #endif // defined(__i386__) && defined(__pic__) | |
| 55 } | |
| 56 | |
| 57 #endif // !V8_LIBC_MSVCRT | |
| 58 | |
| 59 #elif V8_HOST_ARCH_ARM || V8_HOST_ARCH_ARM64 || V8_HOST_ARCH_MIPS | |
| 60 | |
| 61 #if V8_OS_LINUX | |
| 62 | |
| 63 #if V8_HOST_ARCH_ARM | |
| 64 | |
| 65 // See <uapi/asm/hwcap.h> kernel header. | |
| 66 /* | |
| 67 * HWCAP flags - for elf_hwcap (in kernel) and AT_HWCAP | |
| 68 */ | |
| 69 #define HWCAP_SWP (1 << 0) | |
| 70 #define HWCAP_HALF (1 << 1) | |
| 71 #define HWCAP_THUMB (1 << 2) | |
| 72 #define HWCAP_26BIT (1 << 3) /* Play it safe */ | |
| 73 #define HWCAP_FAST_MULT (1 << 4) | |
| 74 #define HWCAP_FPA (1 << 5) | |
| 75 #define HWCAP_VFP (1 << 6) | |
| 76 #define HWCAP_EDSP (1 << 7) | |
| 77 #define HWCAP_JAVA (1 << 8) | |
| 78 #define HWCAP_IWMMXT (1 << 9) | |
| 79 #define HWCAP_CRUNCH (1 << 10) | |
| 80 #define HWCAP_THUMBEE (1 << 11) | |
| 81 #define HWCAP_NEON (1 << 12) | |
| 82 #define HWCAP_VFPv3 (1 << 13) | |
| 83 #define HWCAP_VFPv3D16 (1 << 14) /* also set for VFPv4-D16 */ | |
| 84 #define HWCAP_TLS (1 << 15) | |
| 85 #define HWCAP_VFPv4 (1 << 16) | |
| 86 #define HWCAP_IDIVA (1 << 17) | |
| 87 #define HWCAP_IDIVT (1 << 18) | |
| 88 #define HWCAP_VFPD32 (1 << 19) /* set if VFP has 32 regs (not 16) */ | |
| 89 #define HWCAP_IDIV (HWCAP_IDIVA | HWCAP_IDIVT) | |
| 90 #define HWCAP_LPAE (1 << 20) | |
| 91 | |
| 92 #define AT_HWCAP 16 | |
| 93 | |
| 94 // Read the ELF HWCAP flags by parsing /proc/self/auxv. | |
| 95 static uint32_t ReadELFHWCaps() { | |
| 96 uint32_t result = 0; | |
| 97 FILE* fp = fopen("/proc/self/auxv", "r"); | |
| 98 if (fp != NULL) { | |
| 99 struct { uint32_t tag; uint32_t value; } entry; | |
| 100 for (;;) { | |
| 101 size_t n = fread(&entry, sizeof(entry), 1, fp); | |
| 102 if (n == 0 || (entry.tag == 0 && entry.value == 0)) { | |
| 103 break; | |
| 104 } | |
| 105 if (entry.tag == AT_HWCAP) { | |
| 106 result = entry.value; | |
| 107 break; | |
| 108 } | |
| 109 } | |
| 110 fclose(fp); | |
| 111 } | |
| 112 return result; | |
| 113 } | |
| 114 | |
| 115 #endif // V8_HOST_ARCH_ARM | |
| 116 | |
| 117 // Extract the information exposed by the kernel via /proc/cpuinfo. | |
| 118 class CPUInfo V8_FINAL BASE_EMBEDDED { | |
| 119 public: | |
| 120 CPUInfo() : datalen_(0) { | |
| 121 // Get the size of the cpuinfo file by reading it until the end. This is | |
| 122 // required because files under /proc do not always return a valid size | |
| 123 // when using fseek(0, SEEK_END) + ftell(). Nor can the be mmap()-ed. | |
| 124 static const char PATHNAME[] = "/proc/cpuinfo"; | |
| 125 FILE* fp = fopen(PATHNAME, "r"); | |
| 126 if (fp != NULL) { | |
| 127 for (;;) { | |
| 128 char buffer[256]; | |
| 129 size_t n = fread(buffer, 1, sizeof(buffer), fp); | |
| 130 if (n == 0) { | |
| 131 break; | |
| 132 } | |
| 133 datalen_ += n; | |
| 134 } | |
| 135 fclose(fp); | |
| 136 } | |
| 137 | |
| 138 // Read the contents of the cpuinfo file. | |
| 139 data_ = new char[datalen_ + 1]; | |
| 140 fp = fopen(PATHNAME, "r"); | |
| 141 if (fp != NULL) { | |
| 142 for (size_t offset = 0; offset < datalen_; ) { | |
| 143 size_t n = fread(data_ + offset, 1, datalen_ - offset, fp); | |
| 144 if (n == 0) { | |
| 145 break; | |
| 146 } | |
| 147 offset += n; | |
| 148 } | |
| 149 fclose(fp); | |
| 150 } | |
| 151 | |
| 152 // Zero-terminate the data. | |
| 153 data_[datalen_] = '\0'; | |
| 154 } | |
| 155 | |
| 156 ~CPUInfo() { | |
| 157 delete[] data_; | |
| 158 } | |
| 159 | |
| 160 // Extract the content of a the first occurence of a given field in | |
| 161 // the content of the cpuinfo file and return it as a heap-allocated | |
| 162 // string that must be freed by the caller using delete[]. | |
| 163 // Return NULL if not found. | |
| 164 char* ExtractField(const char* field) const { | |
| 165 ASSERT(field != NULL); | |
| 166 | |
| 167 // Look for first field occurence, and ensure it starts the line. | |
| 168 size_t fieldlen = strlen(field); | |
| 169 char* p = data_; | |
| 170 for (;;) { | |
| 171 p = strstr(p, field); | |
| 172 if (p == NULL) { | |
| 173 return NULL; | |
| 174 } | |
| 175 if (p == data_ || p[-1] == '\n') { | |
| 176 break; | |
| 177 } | |
| 178 p += fieldlen; | |
| 179 } | |
| 180 | |
| 181 // Skip to the first colon followed by a space. | |
| 182 p = strchr(p + fieldlen, ':'); | |
| 183 if (p == NULL || !isspace(p[1])) { | |
| 184 return NULL; | |
| 185 } | |
| 186 p += 2; | |
| 187 | |
| 188 // Find the end of the line. | |
| 189 char* q = strchr(p, '\n'); | |
| 190 if (q == NULL) { | |
| 191 q = data_ + datalen_; | |
| 192 } | |
| 193 | |
| 194 // Copy the line into a heap-allocated buffer. | |
| 195 size_t len = q - p; | |
| 196 char* result = new char[len + 1]; | |
| 197 if (result != NULL) { | |
| 198 memcpy(result, p, len); | |
| 199 result[len] = '\0'; | |
| 200 } | |
| 201 return result; | |
| 202 } | |
| 203 | |
| 204 private: | |
| 205 char* data_; | |
| 206 size_t datalen_; | |
| 207 }; | |
| 208 | |
| 209 #if V8_HOST_ARCH_ARM || V8_HOST_ARCH_MIPS | |
| 210 | |
| 211 // Checks that a space-separated list of items contains one given 'item'. | |
| 212 static bool HasListItem(const char* list, const char* item) { | |
| 213 ssize_t item_len = strlen(item); | |
| 214 const char* p = list; | |
| 215 if (p != NULL) { | |
| 216 while (*p != '\0') { | |
| 217 // Skip whitespace. | |
| 218 while (isspace(*p)) ++p; | |
| 219 | |
| 220 // Find end of current list item. | |
| 221 const char* q = p; | |
| 222 while (*q != '\0' && !isspace(*q)) ++q; | |
| 223 | |
| 224 if (item_len == q - p && memcmp(p, item, item_len) == 0) { | |
| 225 return true; | |
| 226 } | |
| 227 | |
| 228 // Skip to next item. | |
| 229 p = q; | |
| 230 } | |
| 231 } | |
| 232 return false; | |
| 233 } | |
| 234 | |
| 235 #endif // V8_HOST_ARCH_ARM || V8_HOST_ARCH_MIPS | |
| 236 | |
| 237 #endif // V8_OS_LINUX | |
| 238 | |
| 239 #endif // V8_HOST_ARCH_IA32 || V8_HOST_ARCH_X64 | |
| 240 | |
| 241 CPU::CPU() : stepping_(0), | |
| 242 model_(0), | |
| 243 ext_model_(0), | |
| 244 family_(0), | |
| 245 ext_family_(0), | |
| 246 type_(0), | |
| 247 implementer_(0), | |
| 248 architecture_(0), | |
| 249 part_(0), | |
| 250 has_fpu_(false), | |
| 251 has_cmov_(false), | |
| 252 has_sahf_(false), | |
| 253 has_mmx_(false), | |
| 254 has_sse_(false), | |
| 255 has_sse2_(false), | |
| 256 has_sse3_(false), | |
| 257 has_ssse3_(false), | |
| 258 has_sse41_(false), | |
| 259 has_sse42_(false), | |
| 260 has_idiva_(false), | |
| 261 has_neon_(false), | |
| 262 has_thumb2_(false), | |
| 263 has_vfp_(false), | |
| 264 has_vfp3_(false), | |
| 265 has_vfp3_d32_(false) { | |
| 266 memcpy(vendor_, "Unknown", 8); | |
| 267 #if V8_HOST_ARCH_IA32 || V8_HOST_ARCH_X64 | |
| 268 int cpu_info[4]; | |
| 269 | |
| 270 // __cpuid with an InfoType argument of 0 returns the number of | |
| 271 // valid Ids in CPUInfo[0] and the CPU identification string in | |
| 272 // the other three array elements. The CPU identification string is | |
| 273 // not in linear order. The code below arranges the information | |
| 274 // in a human readable form. The human readable order is CPUInfo[1] | | |
| 275 // CPUInfo[3] | CPUInfo[2]. CPUInfo[2] and CPUInfo[3] are swapped | |
| 276 // before using memcpy to copy these three array elements to cpu_string. | |
| 277 __cpuid(cpu_info, 0); | |
| 278 unsigned num_ids = cpu_info[0]; | |
| 279 std::swap(cpu_info[2], cpu_info[3]); | |
| 280 memcpy(vendor_, cpu_info + 1, 12); | |
| 281 vendor_[12] = '\0'; | |
| 282 | |
| 283 // Interpret CPU feature information. | |
| 284 if (num_ids > 0) { | |
| 285 __cpuid(cpu_info, 1); | |
| 286 stepping_ = cpu_info[0] & 0xf; | |
| 287 model_ = ((cpu_info[0] >> 4) & 0xf) + ((cpu_info[0] >> 12) & 0xf0); | |
| 288 family_ = (cpu_info[0] >> 8) & 0xf; | |
| 289 type_ = (cpu_info[0] >> 12) & 0x3; | |
| 290 ext_model_ = (cpu_info[0] >> 16) & 0xf; | |
| 291 ext_family_ = (cpu_info[0] >> 20) & 0xff; | |
| 292 has_fpu_ = (cpu_info[3] & 0x00000001) != 0; | |
| 293 has_cmov_ = (cpu_info[3] & 0x00008000) != 0; | |
| 294 has_mmx_ = (cpu_info[3] & 0x00800000) != 0; | |
| 295 has_sse_ = (cpu_info[3] & 0x02000000) != 0; | |
| 296 has_sse2_ = (cpu_info[3] & 0x04000000) != 0; | |
| 297 has_sse3_ = (cpu_info[2] & 0x00000001) != 0; | |
| 298 has_ssse3_ = (cpu_info[2] & 0x00000200) != 0; | |
| 299 has_sse41_ = (cpu_info[2] & 0x00080000) != 0; | |
| 300 has_sse42_ = (cpu_info[2] & 0x00100000) != 0; | |
| 301 } | |
| 302 | |
| 303 #if V8_HOST_ARCH_IA32 | |
| 304 // SAHF is always available in compat/legacy mode, | |
| 305 has_sahf_ = true; | |
| 306 #else | |
| 307 // Query extended IDs. | |
| 308 __cpuid(cpu_info, 0x80000000); | |
| 309 unsigned num_ext_ids = cpu_info[0]; | |
| 310 | |
| 311 // Interpret extended CPU feature information. | |
| 312 if (num_ext_ids > 0x80000000) { | |
| 313 __cpuid(cpu_info, 0x80000001); | |
| 314 // SAHF must be probed in long mode. | |
| 315 has_sahf_ = (cpu_info[2] & 0x00000001) != 0; | |
| 316 } | |
| 317 #endif | |
| 318 | |
| 319 #elif V8_HOST_ARCH_ARM | |
| 320 | |
| 321 #if V8_OS_LINUX | |
| 322 | |
| 323 CPUInfo cpu_info; | |
| 324 | |
| 325 // Extract implementor from the "CPU implementer" field. | |
| 326 char* implementer = cpu_info.ExtractField("CPU implementer"); | |
| 327 if (implementer != NULL) { | |
| 328 char* end ; | |
| 329 implementer_ = strtol(implementer, &end, 0); | |
| 330 if (end == implementer) { | |
| 331 implementer_ = 0; | |
| 332 } | |
| 333 delete[] implementer; | |
| 334 } | |
| 335 | |
| 336 // Extract part number from the "CPU part" field. | |
| 337 char* part = cpu_info.ExtractField("CPU part"); | |
| 338 if (part != NULL) { | |
| 339 char* end ; | |
| 340 part_ = strtol(part, &end, 0); | |
| 341 if (end == part) { | |
| 342 part_ = 0; | |
| 343 } | |
| 344 delete[] part; | |
| 345 } | |
| 346 | |
| 347 // Extract architecture from the "CPU Architecture" field. | |
| 348 // The list is well-known, unlike the the output of | |
| 349 // the 'Processor' field which can vary greatly. | |
| 350 // See the definition of the 'proc_arch' array in | |
| 351 // $KERNEL/arch/arm/kernel/setup.c and the 'c_show' function in | |
| 352 // same file. | |
| 353 char* architecture = cpu_info.ExtractField("CPU architecture"); | |
| 354 if (architecture != NULL) { | |
| 355 char* end; | |
| 356 architecture_ = strtol(architecture, &end, 10); | |
| 357 if (end == architecture) { | |
| 358 architecture_ = 0; | |
| 359 } | |
| 360 delete[] architecture; | |
| 361 | |
| 362 // Unfortunately, it seems that certain ARMv6-based CPUs | |
| 363 // report an incorrect architecture number of 7! | |
| 364 // | |
| 365 // See http://code.google.com/p/android/issues/detail?id=10812 | |
| 366 // | |
| 367 // We try to correct this by looking at the 'elf_format' | |
| 368 // field reported by the 'Processor' field, which is of the | |
| 369 // form of "(v7l)" for an ARMv7-based CPU, and "(v6l)" for | |
| 370 // an ARMv6-one. For example, the Raspberry Pi is one popular | |
| 371 // ARMv6 device that reports architecture 7. | |
| 372 if (architecture_ == 7) { | |
| 373 char* processor = cpu_info.ExtractField("Processor"); | |
| 374 if (HasListItem(processor, "(v6l)")) { | |
| 375 architecture_ = 6; | |
| 376 } | |
| 377 delete[] processor; | |
| 378 } | |
| 379 } | |
| 380 | |
| 381 // Try to extract the list of CPU features from ELF hwcaps. | |
| 382 uint32_t hwcaps = ReadELFHWCaps(); | |
| 383 if (hwcaps != 0) { | |
| 384 has_idiva_ = (hwcaps & HWCAP_IDIVA) != 0; | |
| 385 has_neon_ = (hwcaps & HWCAP_NEON) != 0; | |
| 386 has_vfp_ = (hwcaps & HWCAP_VFP) != 0; | |
| 387 has_vfp3_ = (hwcaps & (HWCAP_VFPv3 | HWCAP_VFPv3D16 | HWCAP_VFPv4)) != 0; | |
| 388 has_vfp3_d32_ = (has_vfp3_ && ((hwcaps & HWCAP_VFPv3D16) == 0 || | |
| 389 (hwcaps & HWCAP_VFPD32) != 0)); | |
| 390 } else { | |
| 391 // Try to fallback to "Features" CPUInfo field. | |
| 392 char* features = cpu_info.ExtractField("Features"); | |
| 393 has_idiva_ = HasListItem(features, "idiva"); | |
| 394 has_neon_ = HasListItem(features, "neon"); | |
| 395 has_thumb2_ = HasListItem(features, "thumb2"); | |
| 396 has_vfp_ = HasListItem(features, "vfp"); | |
| 397 if (HasListItem(features, "vfpv3d16")) { | |
| 398 has_vfp3_ = true; | |
| 399 } else if (HasListItem(features, "vfpv3")) { | |
| 400 has_vfp3_ = true; | |
| 401 has_vfp3_d32_ = true; | |
| 402 } | |
| 403 delete[] features; | |
| 404 } | |
| 405 | |
| 406 // Some old kernels will report vfp not vfpv3. Here we make an attempt | |
| 407 // to detect vfpv3 by checking for vfp *and* neon, since neon is only | |
| 408 // available on architectures with vfpv3. Checking neon on its own is | |
| 409 // not enough as it is possible to have neon without vfp. | |
| 410 if (has_vfp_ && has_neon_) { | |
| 411 has_vfp3_ = true; | |
| 412 } | |
| 413 | |
| 414 // VFPv3 implies ARMv7, see ARM DDI 0406B, page A1-6. | |
| 415 if (architecture_ < 7 && has_vfp3_) { | |
| 416 architecture_ = 7; | |
| 417 } | |
| 418 | |
| 419 // ARMv7 implies Thumb2. | |
| 420 if (architecture_ >= 7) { | |
| 421 has_thumb2_ = true; | |
| 422 } | |
| 423 | |
| 424 // The earliest architecture with Thumb2 is ARMv6T2. | |
| 425 if (has_thumb2_ && architecture_ < 6) { | |
| 426 architecture_ = 6; | |
| 427 } | |
| 428 | |
| 429 // We don't support any FPUs other than VFP. | |
| 430 has_fpu_ = has_vfp_; | |
| 431 | |
| 432 #elif V8_OS_QNX | |
| 433 | |
| 434 uint32_t cpu_flags = SYSPAGE_ENTRY(cpuinfo)->flags; | |
| 435 if (cpu_flags & ARM_CPU_FLAG_V7) { | |
| 436 architecture_ = 7; | |
| 437 has_thumb2_ = true; | |
| 438 } else if (cpu_flags & ARM_CPU_FLAG_V6) { | |
| 439 architecture_ = 6; | |
| 440 // QNX doesn't say if Thumb2 is available. | |
| 441 // Assume false for the architectures older than ARMv7. | |
| 442 } | |
| 443 ASSERT(architecture_ >= 6); | |
| 444 has_fpu_ = (cpu_flags & CPU_FLAG_FPU) != 0; | |
| 445 has_vfp_ = has_fpu_; | |
| 446 if (cpu_flags & ARM_CPU_FLAG_NEON) { | |
| 447 has_neon_ = true; | |
| 448 has_vfp3_ = has_vfp_; | |
| 449 #ifdef ARM_CPU_FLAG_VFP_D32 | |
| 450 has_vfp3_d32_ = (cpu_flags & ARM_CPU_FLAG_VFP_D32) != 0; | |
| 451 #endif | |
| 452 } | |
| 453 has_idiva_ = (cpu_flags & ARM_CPU_FLAG_IDIV) != 0; | |
| 454 | |
| 455 #endif // V8_OS_LINUX | |
| 456 | |
| 457 #elif V8_HOST_ARCH_MIPS | |
| 458 | |
| 459 // Simple detection of FPU at runtime for Linux. | |
| 460 // It is based on /proc/cpuinfo, which reveals hardware configuration | |
| 461 // to user-space applications. According to MIPS (early 2010), no similar | |
| 462 // facility is universally available on the MIPS architectures, | |
| 463 // so it's up to individual OSes to provide such. | |
| 464 CPUInfo cpu_info; | |
| 465 char* cpu_model = cpu_info.ExtractField("cpu model"); | |
| 466 has_fpu_ = HasListItem(cpu_model, "FPU"); | |
| 467 delete[] cpu_model; | |
| 468 | |
| 469 #elif V8_HOST_ARCH_ARM64 | |
| 470 | |
| 471 CPUInfo cpu_info; | |
| 472 | |
| 473 // Extract implementor from the "CPU implementer" field. | |
| 474 char* implementer = cpu_info.ExtractField("CPU implementer"); | |
| 475 if (implementer != NULL) { | |
| 476 char* end ; | |
| 477 implementer_ = strtol(implementer, &end, 0); | |
| 478 if (end == implementer) { | |
| 479 implementer_ = 0; | |
| 480 } | |
| 481 delete[] implementer; | |
| 482 } | |
| 483 | |
| 484 // Extract part number from the "CPU part" field. | |
| 485 char* part = cpu_info.ExtractField("CPU part"); | |
| 486 if (part != NULL) { | |
| 487 char* end ; | |
| 488 part_ = strtol(part, &end, 0); | |
| 489 if (end == part) { | |
| 490 part_ = 0; | |
| 491 } | |
| 492 delete[] part; | |
| 493 } | |
| 494 | |
| 495 #endif | |
| 496 } | |
| 497 | |
| 498 } } // namespace v8::internal | |
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Chromium Code Reviews
Issue 358363002:
Move platform abstraction to base library (Closed)
Base URL: https://v8.googlecode.com/svn/branches/bleeding_edge