// Copyright 2013 the V8 project authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #include "src/base/cpu.h" #if V8_LIBC_MSVCRT #include // __cpuid() #endif #if V8_OS_LINUX #include // AT_HWCAP #endif #if V8_GLIBC_PREREQ(2, 16) #include // getauxval() #endif #if V8_OS_QNX #include // cpuinfo #endif #if V8_OS_LINUX && V8_HOST_ARCH_PPC #include #endif #if V8_OS_AIX #include // _system_configuration #ifndef POWER_8 #define POWER_8 0x10000 #endif #ifndef POWER_9 #define POWER_9 0x20000 #endif #endif #if V8_OS_POSIX #include // sysconf() #endif #include #include #include #include #include #include #include "src/base/logging.h" #if V8_OS_WIN #include "src/base/win32-headers.h" // NOLINT #endif namespace v8 { namespace base { #if V8_HOST_ARCH_IA32 || V8_HOST_ARCH_X64 // Define __cpuid() for non-MSVC libraries. #if !V8_LIBC_MSVCRT static V8_INLINE void __cpuid(int cpu_info[4], int info_type) { // Clear ecx to align with __cpuid() of MSVC: // https://msdn.microsoft.com/en-us/library/hskdteyh.aspx #if defined(__i386__) && defined(__pic__) // Make sure to preserve ebx, which contains the pointer // to the GOT in case we're generating PIC. __asm__ volatile( "mov %%ebx, %%edi\n\t" "cpuid\n\t" "xchg %%edi, %%ebx\n\t" : "=a"(cpu_info[0]), "=D"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3]) : "a"(info_type), "c"(0)); #else __asm__ volatile("cpuid \n\t" : "=a"(cpu_info[0]), "=b"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3]) : "a"(info_type), "c"(0)); #endif // defined(__i386__) && defined(__pic__) } #endif // !V8_LIBC_MSVCRT #elif V8_HOST_ARCH_ARM || V8_HOST_ARCH_ARM64 \ || V8_HOST_ARCH_MIPS || V8_HOST_ARCH_MIPS64 #if V8_OS_LINUX #if V8_HOST_ARCH_ARM // See kernel header. /* * HWCAP flags - for elf_hwcap (in kernel) and AT_HWCAP */ #define HWCAP_SWP (1 << 0) #define HWCAP_HALF (1 << 1) #define HWCAP_THUMB (1 << 2) #define HWCAP_26BIT (1 << 3) /* Play it safe */ #define HWCAP_FAST_MULT (1 << 4) #define HWCAP_FPA (1 << 5) #define HWCAP_VFP (1 << 6) #define HWCAP_EDSP (1 << 7) #define HWCAP_JAVA (1 << 8) #define HWCAP_IWMMXT (1 << 9) #define HWCAP_CRUNCH (1 << 10) #define HWCAP_THUMBEE (1 << 11) #define HWCAP_NEON (1 << 12) #define HWCAP_VFPv3 (1 << 13) #define HWCAP_VFPv3D16 (1 << 14) /* also set for VFPv4-D16 */ #define HWCAP_TLS (1 << 15) #define HWCAP_VFPv4 (1 << 16) #define HWCAP_IDIVA (1 << 17) #define HWCAP_IDIVT (1 << 18) #define HWCAP_VFPD32 (1 << 19) /* set if VFP has 32 regs (not 16) */ #define HWCAP_IDIV (HWCAP_IDIVA | HWCAP_IDIVT) #define HWCAP_LPAE (1 << 20) static uint32_t ReadELFHWCaps() { uint32_t result = 0; #if V8_GLIBC_PREREQ(2, 16) result = static_cast(getauxval(AT_HWCAP)); #else // Read the ELF HWCAP flags by parsing /proc/self/auxv. FILE* fp = fopen("/proc/self/auxv", "r"); if (fp != NULL) { struct { uint32_t tag; uint32_t value; } entry; for (;;) { size_t n = fread(&entry, sizeof(entry), 1, fp); if (n == 0 || (entry.tag == 0 && entry.value == 0)) { break; } if (entry.tag == AT_HWCAP) { result = entry.value; break; } } fclose(fp); } #endif return result; } #endif // V8_HOST_ARCH_ARM #if V8_HOST_ARCH_MIPS int __detect_fp64_mode(void) { double result = 0; // Bit representation of (double)1 is 0x3FF0000000000000. __asm__ volatile( ".set push\n\t" ".set noreorder\n\t" ".set oddspreg\n\t" "lui $t0, 0x3FF0\n\t" "ldc1 $f0, %0\n\t" "mtc1 $t0, $f1\n\t" "sdc1 $f0, %0\n\t" ".set pop\n\t" : "+m"(result) : : "t0", "$f0", "$f1", "memory"); return !(result == 1); } int __detect_mips_arch_revision(void) { // TODO(dusmil): Do the specific syscall as soon as it is implemented in mips // kernel. uint32_t result = 0; __asm__ volatile( "move $v0, $zero\n\t" // Encoding for "addi $v0, $v0, 1" on non-r6, // which is encoding for "bovc $v0, %v0, 1" on r6. // Use machine code directly to avoid compilation errors with different // toolchains and maintain compatibility. ".word 0x20420001\n\t" "sw $v0, %0\n\t" : "=m"(result) : : "v0", "memory"); // Result is 0 on r6 architectures, 1 on other architecture revisions. // Fall-back to the least common denominator which is mips32 revision 1. return result ? 1 : 6; } #endif // Extract the information exposed by the kernel via /proc/cpuinfo. class CPUInfo final { public: CPUInfo() : datalen_(0) { // Get the size of the cpuinfo file by reading it until the end. This is // required because files under /proc do not always return a valid size // when using fseek(0, SEEK_END) + ftell(). Nor can the be mmap()-ed. static const char PATHNAME[] = "/proc/cpuinfo"; FILE* fp = fopen(PATHNAME, "r"); if (fp != NULL) { for (;;) { char buffer[256]; size_t n = fread(buffer, 1, sizeof(buffer), fp); if (n == 0) { break; } datalen_ += n; } fclose(fp); } // Read the contents of the cpuinfo file. data_ = new char[datalen_ + 1]; fp = fopen(PATHNAME, "r"); if (fp != NULL) { for (size_t offset = 0; offset < datalen_; ) { size_t n = fread(data_ + offset, 1, datalen_ - offset, fp); if (n == 0) { break; } offset += n; } fclose(fp); } // Zero-terminate the data. data_[datalen_] = '\0'; } ~CPUInfo() { delete[] data_; } // Extract the content of a the first occurence of a given field in // the content of the cpuinfo file and return it as a heap-allocated // string that must be freed by the caller using delete[]. // Return NULL if not found. char* ExtractField(const char* field) const { DCHECK(field != NULL); // Look for first field occurence, and ensure it starts the line. size_t fieldlen = strlen(field); char* p = data_; for (;;) { p = strstr(p, field); if (p == NULL) { return NULL; } if (p == data_ || p[-1] == '\n') { break; } p += fieldlen; } // Skip to the first colon followed by a space. p = strchr(p + fieldlen, ':'); if (p == NULL || !isspace(p[1])) { return NULL; } p += 2; // Find the end of the line. char* q = strchr(p, '\n'); if (q == NULL) { q = data_ + datalen_; } // Copy the line into a heap-allocated buffer. size_t len = q - p; char* result = new char[len + 1]; if (result != NULL) { memcpy(result, p, len); result[len] = '\0'; } return result; } private: char* data_; size_t datalen_; }; #if V8_HOST_ARCH_ARM || V8_HOST_ARCH_MIPS || V8_HOST_ARCH_MIPS64 // Checks that a space-separated list of items contains one given 'item'. static bool HasListItem(const char* list, const char* item) { ssize_t item_len = strlen(item); const char* p = list; if (p != NULL) { while (*p != '\0') { // Skip whitespace. while (isspace(*p)) ++p; // Find end of current list item. const char* q = p; while (*q != '\0' && !isspace(*q)) ++q; if (item_len == q - p && memcmp(p, item, item_len) == 0) { return true; } // Skip to next item. p = q; } } return false; } #endif // V8_HOST_ARCH_ARM || V8_HOST_ARCH_MIPS || V8_HOST_ARCH_MIPS64 #endif // V8_OS_LINUX #endif // V8_HOST_ARCH_IA32 || V8_HOST_ARCH_X64 CPU::CPU() : stepping_(0), model_(0), ext_model_(0), family_(0), ext_family_(0), type_(0), implementer_(0), architecture_(0), variant_(-1), part_(0), icache_line_size_(UNKNOWN_CACHE_LINE_SIZE), dcache_line_size_(UNKNOWN_CACHE_LINE_SIZE), has_fpu_(false), has_cmov_(false), has_sahf_(false), has_mmx_(false), has_sse_(false), has_sse2_(false), has_sse3_(false), has_ssse3_(false), has_sse41_(false), has_sse42_(false), is_atom_(false), has_osxsave_(false), has_avx_(false), has_fma3_(false), has_bmi1_(false), has_bmi2_(false), has_lzcnt_(false), has_popcnt_(false), has_idiva_(false), has_neon_(false), has_thumb2_(false), has_vfp_(false), has_vfp3_(false), has_vfp3_d32_(false), is_fp64_mode_(false), has_non_stop_time_stamp_counter_(false) { memcpy(vendor_, "Unknown", 8); #if V8_HOST_ARCH_IA32 || V8_HOST_ARCH_X64 int cpu_info[4]; // __cpuid with an InfoType argument of 0 returns the number of // valid Ids in CPUInfo[0] and the CPU identification string in // the other three array elements. The CPU identification string is // not in linear order. The code below arranges the information // in a human readable form. The human readable order is CPUInfo[1] | // CPUInfo[3] | CPUInfo[2]. CPUInfo[2] and CPUInfo[3] are swapped // before using memcpy to copy these three array elements to cpu_string. __cpuid(cpu_info, 0); unsigned num_ids = cpu_info[0]; std::swap(cpu_info[2], cpu_info[3]); memcpy(vendor_, cpu_info + 1, 12); vendor_[12] = '\0'; // Interpret CPU feature information. if (num_ids > 0) { __cpuid(cpu_info, 1); stepping_ = cpu_info[0] & 0xf; model_ = ((cpu_info[0] >> 4) & 0xf) + ((cpu_info[0] >> 12) & 0xf0); family_ = (cpu_info[0] >> 8) & 0xf; type_ = (cpu_info[0] >> 12) & 0x3; ext_model_ = (cpu_info[0] >> 16) & 0xf; ext_family_ = (cpu_info[0] >> 20) & 0xff; has_fpu_ = (cpu_info[3] & 0x00000001) != 0; has_cmov_ = (cpu_info[3] & 0x00008000) != 0; has_mmx_ = (cpu_info[3] & 0x00800000) != 0; has_sse_ = (cpu_info[3] & 0x02000000) != 0; has_sse2_ = (cpu_info[3] & 0x04000000) != 0; has_sse3_ = (cpu_info[2] & 0x00000001) != 0; has_ssse3_ = (cpu_info[2] & 0x00000200) != 0; has_sse41_ = (cpu_info[2] & 0x00080000) != 0; has_sse42_ = (cpu_info[2] & 0x00100000) != 0; has_popcnt_ = (cpu_info[2] & 0x00800000) != 0; has_osxsave_ = (cpu_info[2] & 0x08000000) != 0; has_avx_ = (cpu_info[2] & 0x10000000) != 0; has_fma3_ = (cpu_info[2] & 0x00001000) != 0; if (family_ == 0x6) { switch (model_) { case 0x1c: // SLT case 0x26: case 0x36: case 0x27: case 0x35: case 0x37: // SLM case 0x4a: case 0x4d: case 0x4c: // AMT case 0x6e: is_atom_ = true; } } } // There are separate feature flags for VEX-encoded GPR instructions. if (num_ids >= 7) { __cpuid(cpu_info, 7); has_bmi1_ = (cpu_info[1] & 0x00000008) != 0; has_bmi2_ = (cpu_info[1] & 0x00000100) != 0; } // Query extended IDs. __cpuid(cpu_info, 0x80000000); unsigned num_ext_ids = cpu_info[0]; // Interpret extended CPU feature information. if (num_ext_ids > 0x80000000) { __cpuid(cpu_info, 0x80000001); has_lzcnt_ = (cpu_info[2] & 0x00000020) != 0; // SAHF must be probed in long mode. has_sahf_ = (cpu_info[2] & 0x00000001) != 0; } // Check if CPU has non stoppable time stamp counter. const unsigned parameter_containing_non_stop_time_stamp_counter = 0x80000007; if (num_ext_ids >= parameter_containing_non_stop_time_stamp_counter) { __cpuid(cpu_info, parameter_containing_non_stop_time_stamp_counter); has_non_stop_time_stamp_counter_ = (cpu_info[3] & (1 << 8)) != 0; } #elif V8_HOST_ARCH_ARM #if V8_OS_LINUX CPUInfo cpu_info; // Extract implementor from the "CPU implementer" field. char* implementer = cpu_info.ExtractField("CPU implementer"); if (implementer != NULL) { char* end; implementer_ = strtol(implementer, &end, 0); if (end == implementer) { implementer_ = 0; } delete[] implementer; } char* variant = cpu_info.ExtractField("CPU variant"); if (variant != NULL) { char* end; variant_ = strtol(variant, &end, 0); if (end == variant) { variant_ = -1; } delete[] variant; } // Extract part number from the "CPU part" field. char* part = cpu_info.ExtractField("CPU part"); if (part != NULL) { char* end; part_ = strtol(part, &end, 0); if (end == part) { part_ = 0; } delete[] part; } // Extract architecture from the "CPU Architecture" field. // The list is well-known, unlike the the output of // the 'Processor' field which can vary greatly. // See the definition of the 'proc_arch' array in // $KERNEL/arch/arm/kernel/setup.c and the 'c_show' function in // same file. char* architecture = cpu_info.ExtractField("CPU architecture"); if (architecture != NULL) { char* end; architecture_ = strtol(architecture, &end, 10); if (end == architecture) { // Kernels older than 3.18 report "CPU architecture: AArch64" on ARMv8. if (strcmp(architecture, "AArch64") == 0) { architecture_ = 8; } else { architecture_ = 0; } } delete[] architecture; // Unfortunately, it seems that certain ARMv6-based CPUs // report an incorrect architecture number of 7! // // See http://code.google.com/p/android/issues/detail?id=10812 // // We try to correct this by looking at the 'elf_platform' // field reported by the 'Processor' field, which is of the // form of "(v7l)" for an ARMv7-based CPU, and "(v6l)" for // an ARMv6-one. For example, the Raspberry Pi is one popular // ARMv6 device that reports architecture 7. if (architecture_ == 7) { char* processor = cpu_info.ExtractField("Processor"); if (HasListItem(processor, "(v6l)")) { architecture_ = 6; } delete[] processor; } // elf_platform moved to the model name field in Linux v3.8. if (architecture_ == 7) { char* processor = cpu_info.ExtractField("model name"); if (HasListItem(processor, "(v6l)")) { architecture_ = 6; } delete[] processor; } } // Try to extract the list of CPU features from ELF hwcaps. uint32_t hwcaps = ReadELFHWCaps(); if (hwcaps != 0) { has_idiva_ = (hwcaps & HWCAP_IDIVA) != 0; has_neon_ = (hwcaps & HWCAP_NEON) != 0; has_vfp_ = (hwcaps & HWCAP_VFP) != 0; has_vfp3_ = (hwcaps & (HWCAP_VFPv3 | HWCAP_VFPv3D16 | HWCAP_VFPv4)) != 0; has_vfp3_d32_ = (has_vfp3_ && ((hwcaps & HWCAP_VFPv3D16) == 0 || (hwcaps & HWCAP_VFPD32) != 0)); } else { // Try to fallback to "Features" CPUInfo field. char* features = cpu_info.ExtractField("Features"); has_idiva_ = HasListItem(features, "idiva"); has_neon_ = HasListItem(features, "neon"); has_thumb2_ = HasListItem(features, "thumb2"); has_vfp_ = HasListItem(features, "vfp"); if (HasListItem(features, "vfpv3d16")) { has_vfp3_ = true; } else if (HasListItem(features, "vfpv3")) { has_vfp3_ = true; has_vfp3_d32_ = true; } delete[] features; } // Some old kernels will report vfp not vfpv3. Here we make an attempt // to detect vfpv3 by checking for vfp *and* neon, since neon is only // available on architectures with vfpv3. Checking neon on its own is // not enough as it is possible to have neon without vfp. if (has_vfp_ && has_neon_) { has_vfp3_ = true; } // VFPv3 implies ARMv7, see ARM DDI 0406B, page A1-6. if (architecture_ < 7 && has_vfp3_) { architecture_ = 7; } // ARMv7 implies Thumb2. if (architecture_ >= 7) { has_thumb2_ = true; } // The earliest architecture with Thumb2 is ARMv6T2. if (has_thumb2_ && architecture_ < 6) { architecture_ = 6; } // We don't support any FPUs other than VFP. has_fpu_ = has_vfp_; #elif V8_OS_QNX uint32_t cpu_flags = SYSPAGE_ENTRY(cpuinfo)->flags; if (cpu_flags & ARM_CPU_FLAG_V7) { architecture_ = 7; has_thumb2_ = true; } else if (cpu_flags & ARM_CPU_FLAG_V6) { architecture_ = 6; // QNX doesn't say if Thumb2 is available. // Assume false for the architectures older than ARMv7. } DCHECK(architecture_ >= 6); has_fpu_ = (cpu_flags & CPU_FLAG_FPU) != 0; has_vfp_ = has_fpu_; if (cpu_flags & ARM_CPU_FLAG_NEON) { has_neon_ = true; has_vfp3_ = has_vfp_; #ifdef ARM_CPU_FLAG_VFP_D32 has_vfp3_d32_ = (cpu_flags & ARM_CPU_FLAG_VFP_D32) != 0; #endif } has_idiva_ = (cpu_flags & ARM_CPU_FLAG_IDIV) != 0; #endif // V8_OS_LINUX #elif V8_HOST_ARCH_MIPS || V8_HOST_ARCH_MIPS64 // Simple detection of FPU at runtime for Linux. // It is based on /proc/cpuinfo, which reveals hardware configuration // to user-space applications. According to MIPS (early 2010), no similar // facility is universally available on the MIPS architectures, // so it's up to individual OSes to provide such. CPUInfo cpu_info; char* cpu_model = cpu_info.ExtractField("cpu model"); has_fpu_ = HasListItem(cpu_model, "FPU"); delete[] cpu_model; #ifdef V8_HOST_ARCH_MIPS is_fp64_mode_ = __detect_fp64_mode(); architecture_ = __detect_mips_arch_revision(); #endif #elif V8_HOST_ARCH_ARM64 CPUInfo cpu_info; // Extract implementor from the "CPU implementer" field. char* implementer = cpu_info.ExtractField("CPU implementer"); if (implementer != NULL) { char* end; implementer_ = static_cast(strtol(implementer, &end, 0)); if (end == implementer) { implementer_ = 0; } delete[] implementer; } char* variant = cpu_info.ExtractField("CPU variant"); if (variant != NULL) { char* end; variant_ = static_cast(strtol(variant, &end, 0)); if (end == variant) { variant_ = -1; } delete[] variant; } // Extract part number from the "CPU part" field. char* part = cpu_info.ExtractField("CPU part"); if (part != NULL) { char* end; part_ = static_cast(strtol(part, &end, 0)); if (end == part) { part_ = 0; } delete[] part; } #elif V8_HOST_ARCH_PPC #ifndef USE_SIMULATOR #if V8_OS_LINUX // Read processor info from /proc/self/auxv. char* auxv_cpu_type = NULL; FILE* fp = fopen("/proc/self/auxv", "r"); if (fp != NULL) { #if V8_TARGET_ARCH_PPC64 Elf64_auxv_t entry; #else Elf32_auxv_t entry; #endif for (;;) { size_t n = fread(&entry, sizeof(entry), 1, fp); if (n == 0 || entry.a_type == AT_NULL) { break; } switch (entry.a_type) { case AT_PLATFORM: auxv_cpu_type = reinterpret_cast(entry.a_un.a_val); break; case AT_ICACHEBSIZE: icache_line_size_ = entry.a_un.a_val; break; case AT_DCACHEBSIZE: dcache_line_size_ = entry.a_un.a_val; break; } } fclose(fp); } part_ = -1; if (auxv_cpu_type) { if (strcmp(auxv_cpu_type, "power9") == 0) { part_ = PPC_POWER9; } else if (strcmp(auxv_cpu_type, "power8") == 0) { part_ = PPC_POWER8; } else if (strcmp(auxv_cpu_type, "power7") == 0) { part_ = PPC_POWER7; } else if (strcmp(auxv_cpu_type, "power6") == 0) { part_ = PPC_POWER6; } else if (strcmp(auxv_cpu_type, "power5") == 0) { part_ = PPC_POWER5; } else if (strcmp(auxv_cpu_type, "ppc970") == 0) { part_ = PPC_G5; } else if (strcmp(auxv_cpu_type, "ppc7450") == 0) { part_ = PPC_G4; } else if (strcmp(auxv_cpu_type, "pa6t") == 0) { part_ = PPC_PA6T; } } #elif V8_OS_AIX switch (_system_configuration.implementation) { case POWER_9: part_ = PPC_POWER9; break; case POWER_8: part_ = PPC_POWER8; break; case POWER_7: part_ = PPC_POWER7; break; case POWER_6: part_ = PPC_POWER6; break; case POWER_5: part_ = PPC_POWER5; break; } #endif // V8_OS_AIX #endif // !USE_SIMULATOR #endif // V8_HOST_ARCH_PPC } } // namespace base } // namespace v8