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Diffstat (limited to 'platform/android/cpu-features.c')
| -rw-r--r-- | platform/android/cpu-features.c | 1089 |
1 files changed, 0 insertions, 1089 deletions
diff --git a/platform/android/cpu-features.c b/platform/android/cpu-features.c deleted file mode 100644 index 9cdadd5407..0000000000 --- a/platform/android/cpu-features.c +++ /dev/null @@ -1,1089 +0,0 @@ -/* - * Copyright (C) 2010 The Android Open Source Project - * All rights reserved. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * * Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * * Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in - * the documentation and/or other materials provided with the - * distribution. - * - * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS - * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT - * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS - * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE - * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, - * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, - * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS - * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED - * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, - * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT - * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF - * SUCH DAMAGE. - */ - -/* ChangeLog for this library: - * - * NDK r8d: Add android_setCpu(). - * - * NDK r8c: Add new ARM CPU features: VFPv2, VFP_D32, VFP_FP16, - * VFP_FMA, NEON_FMA, IDIV_ARM, IDIV_THUMB2 and iWMMXt. - * - * Rewrite the code to parse /proc/self/auxv instead of - * the "Features" field in /proc/cpuinfo. - * - * Dynamically allocate the buffer that hold the content - * of /proc/cpuinfo to deal with newer hardware. - * - * NDK r7c: Fix CPU count computation. The old method only reported the - * number of _active_ CPUs when the library was initialized, - * which could be less than the real total. - * - * NDK r5: Handle buggy kernels which report a CPU Architecture number of 7 - * for an ARMv6 CPU (see below). - * - * Handle kernels that only report 'neon', and not 'vfpv3' - * (VFPv3 is mandated by the ARM architecture is Neon is implemented) - * - * Handle kernels that only report 'vfpv3d16', and not 'vfpv3' - * - * Fix x86 compilation. Report ANDROID_CPU_FAMILY_X86 in - * android_getCpuFamily(). - * - * NDK r4: Initial release - */ - -#if defined(__le32__) - -// When users enter this, we should only provide interface and -// libportable will give the implementations. - -#else // !__le32__ - -#include <sys/system_properties.h> -#include <pthread.h> -#include "cpu-features.h" -#include <stdio.h> -#include <stdlib.h> -#include <fcntl.h> -#include <errno.h> - -static pthread_once_t g_once; -static int g_inited; -static AndroidCpuFamily g_cpuFamily; -static uint64_t g_cpuFeatures; -static int g_cpuCount; - -#ifdef __arm__ -static uint32_t g_cpuIdArm; -#endif - -static const int android_cpufeatures_debug = 0; - -#ifdef __arm__ -# define DEFAULT_CPU_FAMILY ANDROID_CPU_FAMILY_ARM -#elif defined __i386__ -# define DEFAULT_CPU_FAMILY ANDROID_CPU_FAMILY_X86 -#else -# define DEFAULT_CPU_FAMILY ANDROID_CPU_FAMILY_UNKNOWN -#endif - -#define D(...) \ - do { \ - if (android_cpufeatures_debug) { \ - printf(__VA_ARGS__); fflush(stdout); \ - } \ - } while (0) - -#ifdef __i386__ -static __inline__ void x86_cpuid(int func, int values[4]) -{ - int a, b, c, d; - /* We need to preserve ebx since we're compiling PIC code */ - /* this means we can't use "=b" for the second output register */ - __asm__ __volatile__ ( \ - "push %%ebx\n" - "cpuid\n" \ - "mov %%ebx, %1\n" - "pop %%ebx\n" - : "=a" (a), "=r" (b), "=c" (c), "=d" (d) \ - : "a" (func) \ - ); - values[0] = a; - values[1] = b; - values[2] = c; - values[3] = d; -} -#endif - -/* Get the size of a file by reading it until the end. This is needed - * because files under /proc do not always return a valid size when - * using fseek(0, SEEK_END) + ftell(). Nor can they be mmap()-ed. - */ -static int -get_file_size(const char* pathname) -{ - int fd, result = 0; - char buffer[256]; - - fd = open(pathname, O_RDONLY); - if (fd < 0) { - D("Can't open %s: %s\n", pathname, strerror(errno)); - return -1; - } - - for (;;) { - int ret = read(fd, buffer, sizeof buffer); - if (ret < 0) { - if (errno == EINTR) - continue; - D("Error while reading %s: %s\n", pathname, strerror(errno)); - break; - } - if (ret == 0) - break; - - result += ret; - } - close(fd); - return result; -} - -/* Read the content of /proc/cpuinfo into a user-provided buffer. - * Return the length of the data, or -1 on error. Does *not* - * zero-terminate the content. Will not read more - * than 'buffsize' bytes. - */ -static int -read_file(const char* pathname, char* buffer, size_t buffsize) -{ - int fd, count; - - fd = open(pathname, O_RDONLY); - if (fd < 0) { - D("Could not open %s: %s\n", pathname, strerror(errno)); - return -1; - } - count = 0; - while (count < (int)buffsize) { - int ret = read(fd, buffer + count, buffsize - count); - if (ret < 0) { - if (errno == EINTR) - continue; - D("Error while reading from %s: %s\n", pathname, strerror(errno)); - if (count == 0) - count = -1; - break; - } - if (ret == 0) - break; - count += ret; - } - close(fd); - return count; -} - -/* Extract the content of a the first occurence of a given field in - * the content of /proc/cpuinfo and return it as a heap-allocated - * string that must be freed by the caller. - * - * Return NULL if not found - */ -static char* -extract_cpuinfo_field(const char* buffer, int buflen, const char* field) -{ - int fieldlen = strlen(field); - const char* bufend = buffer + buflen; - char* result = NULL; - int len, ignore; - const char *p, *q; - - /* Look for first field occurence, and ensures it starts the line. */ - p = buffer; - for (;;) { - p = memmem(p, bufend-p, field, fieldlen); - if (p == NULL) - goto EXIT; - - if (p == buffer || p[-1] == '\n') - break; - - p += fieldlen; - } - - /* Skip to the first column followed by a space */ - p += fieldlen; - p = memchr(p, ':', bufend-p); - if (p == NULL || p[1] != ' ') - goto EXIT; - - /* Find the end of the line */ - p += 2; - q = memchr(p, '\n', bufend-p); - if (q == NULL) - q = bufend; - - /* Copy the line into a heap-allocated buffer */ - len = q-p; - result = malloc(len+1); - if (result == NULL) - goto EXIT; - - memcpy(result, p, len); - result[len] = '\0'; - -EXIT: - return result; -} - -/* Checks that a space-separated list of items contains one given 'item'. - * Returns 1 if found, 0 otherwise. - */ -static int -has_list_item(const char* list, const char* item) -{ - const char* p = list; - int itemlen = strlen(item); - - if (list == NULL) - return 0; - - while (*p) { - const char* q; - - /* skip spaces */ - while (*p == ' ' || *p == '\t') - p++; - - /* find end of current list item */ - q = p; - while (*q && *q != ' ' && *q != '\t') - q++; - - if (itemlen == q-p && !memcmp(p, item, itemlen)) - return 1; - - /* skip to next item */ - p = q; - } - return 0; -} - -/* Parse a number starting from 'input', but not going further - * than 'limit'. Return the value into '*result'. - * - * NOTE: Does not skip over leading spaces, or deal with sign characters. - * NOTE: Ignores overflows. - * - * The function returns NULL in case of error (bad format), or the new - * position after the decimal number in case of success (which will always - * be <= 'limit'). - */ -static const char* -parse_number(const char* input, const char* limit, int base, int* result) -{ - const char* p = input; - int val = 0; - while (p < limit) { - int d = (*p - '0'); - if ((unsigned)d >= 10U) { - d = (*p - 'a'); - if ((unsigned)d >= 6U) - d = (*p - 'A'); - if ((unsigned)d >= 6U) - break; - d += 10; - } - if (d >= base) - break; - val = val*base + d; - p++; - } - if (p == input) - return NULL; - - *result = val; - return p; -} - -static const char* -parse_decimal(const char* input, const char* limit, int* result) -{ - return parse_number(input, limit, 10, result); -} - -static const char* -parse_hexadecimal(const char* input, const char* limit, int* result) -{ - return parse_number(input, limit, 16, result); -} - -/* This small data type is used to represent a CPU list / mask, as read - * from sysfs on Linux. See http://www.kernel.org/doc/Documentation/cputopology.txt - * - * For now, we don't expect more than 32 cores on mobile devices, so keep - * everything simple. - */ -typedef struct { - uint32_t mask; -} CpuList; - -static __inline__ void -cpulist_init(CpuList* list) { - list->mask = 0; -} - -static __inline__ void -cpulist_and(CpuList* list1, CpuList* list2) { - list1->mask &= list2->mask; -} - -static __inline__ void -cpulist_set(CpuList* list, int index) { - if ((unsigned)index < 32) { - list->mask |= (uint32_t)(1U << index); - } -} - -static __inline__ int -cpulist_count(CpuList* list) { - return __builtin_popcount(list->mask); -} - -/* Parse a textual list of cpus and store the result inside a CpuList object. - * Input format is the following: - * - comma-separated list of items (no spaces) - * - each item is either a single decimal number (cpu index), or a range made - * of two numbers separated by a single dash (-). Ranges are inclusive. - * - * Examples: 0 - * 2,4-127,128-143 - * 0-1 - */ -static void -cpulist_parse(CpuList* list, const char* line, int line_len) -{ - const char* p = line; - const char* end = p + line_len; - const char* q; - - /* NOTE: the input line coming from sysfs typically contains a - * trailing newline, so take care of it in the code below - */ - while (p < end && *p != '\n') - { - int val, start_value, end_value; - - /* Find the end of current item, and put it into 'q' */ - q = memchr(p, ',', end-p); - if (q == NULL) { - q = end; - } - - /* Get first value */ - p = parse_decimal(p, q, &start_value); - if (p == NULL) - goto BAD_FORMAT; - - end_value = start_value; - - /* If we're not at the end of the item, expect a dash and - * and integer; extract end value. - */ - if (p < q && *p == '-') { - p = parse_decimal(p+1, q, &end_value); - if (p == NULL) - goto BAD_FORMAT; - } - - /* Set bits CPU list bits */ - for (val = start_value; val <= end_value; val++) { - cpulist_set(list, val); - } - - /* Jump to next item */ - p = q; - if (p < end) - p++; - } - -BAD_FORMAT: - ; -} - -/* Read a CPU list from one sysfs file */ -static void -cpulist_read_from(CpuList* list, const char* filename) -{ - char file[64]; - int filelen; - - cpulist_init(list); - - filelen = read_file(filename, file, sizeof file); - if (filelen < 0) { - D("Could not read %s: %s\n", filename, strerror(errno)); - return; - } - - cpulist_parse(list, file, filelen); -} - -// See <asm/hwcap.h> kernel header. -#define HWCAP_VFP (1 << 6) -#define HWCAP_IWMMXT (1 << 9) -#define HWCAP_NEON (1 << 12) -#define HWCAP_VFPv3 (1 << 13) -#define HWCAP_VFPv3D16 (1 << 14) -#define HWCAP_VFPv4 (1 << 16) -#define HWCAP_IDIVA (1 << 17) -#define HWCAP_IDIVT (1 << 18) - -#define AT_HWCAP 16 - -#if defined(__arm__) -/* Compute the ELF HWCAP flags. - */ -static uint32_t -get_elf_hwcap(const char* cpuinfo, int cpuinfo_len) -{ - /* IMPORTANT: - * Accessing /proc/self/auxv doesn't work anymore on all - * platform versions. More specifically, when running inside - * a regular application process, most of /proc/self/ will be - * non-readable, including /proc/self/auxv. This doesn't - * happen however if the application is debuggable, or when - * running under the "shell" UID, which is why this was not - * detected appropriately. - */ -#if 0 - uint32_t result = 0; - const char filepath[] = "/proc/self/auxv"; - int fd = open(filepath, O_RDONLY); - if (fd < 0) { - D("Could not open %s: %s\n", filepath, strerror(errno)); - return 0; - } - - struct { uint32_t tag; uint32_t value; } entry; - - for (;;) { - int ret = read(fd, (char*)&entry, sizeof entry); - if (ret < 0) { - if (errno == EINTR) - continue; - D("Error while reading %s: %s\n", filepath, strerror(errno)); - break; - } - // Detect end of list. - if (ret == 0 || (entry.tag == 0 && entry.value == 0)) - break; - if (entry.tag == AT_HWCAP) { - result = entry.value; - break; - } - } - close(fd); - return result; -#else - // Recreate ELF hwcaps by parsing /proc/cpuinfo Features tag. - uint32_t hwcaps = 0; - - char* cpuFeatures = extract_cpuinfo_field(cpuinfo, cpuinfo_len, "Features"); - - if (cpuFeatures != NULL) { - D("Found cpuFeatures = '%s'\n", cpuFeatures); - - if (has_list_item(cpuFeatures, "vfp")) - hwcaps |= HWCAP_VFP; - if (has_list_item(cpuFeatures, "vfpv3")) - hwcaps |= HWCAP_VFPv3; - if (has_list_item(cpuFeatures, "vfpv3d16")) - hwcaps |= HWCAP_VFPv3D16; - if (has_list_item(cpuFeatures, "vfpv4")) - hwcaps |= HWCAP_VFPv4; - if (has_list_item(cpuFeatures, "neon")) - hwcaps |= HWCAP_NEON; - if (has_list_item(cpuFeatures, "idiva")) - hwcaps |= HWCAP_IDIVA; - if (has_list_item(cpuFeatures, "idivt")) - hwcaps |= HWCAP_IDIVT; - if (has_list_item(cpuFeatures, "idiv")) - hwcaps |= HWCAP_IDIVA | HWCAP_IDIVT; - if (has_list_item(cpuFeatures, "iwmmxt")) - hwcaps |= HWCAP_IWMMXT; - - free(cpuFeatures); - } - return hwcaps; -#endif -} -#endif /* __arm__ */ - -/* Return the number of cpus present on a given device. - * - * To handle all weird kernel configurations, we need to compute the - * intersection of the 'present' and 'possible' CPU lists and count - * the result. - */ -static int -get_cpu_count(void) -{ - CpuList cpus_present[1]; - CpuList cpus_possible[1]; - - cpulist_read_from(cpus_present, "/sys/devices/system/cpu/present"); - cpulist_read_from(cpus_possible, "/sys/devices/system/cpu/possible"); - - /* Compute the intersection of both sets to get the actual number of - * CPU cores that can be used on this device by the kernel. - */ - cpulist_and(cpus_present, cpus_possible); - - return cpulist_count(cpus_present); -} - -static void -android_cpuInitFamily(void) -{ -#if defined(__arm__) - g_cpuFamily = ANDROID_CPU_FAMILY_ARM; -#elif defined(__i386__) - g_cpuFamily = ANDROID_CPU_FAMILY_X86; -#elif defined(__mips64) -/* Needs to be before __mips__ since the compiler defines both */ - g_cpuFamily = ANDROID_CPU_FAMILY_MIPS64; -#elif defined(__mips__) - g_cpuFamily = ANDROID_CPU_FAMILY_MIPS; -#elif defined(__aarch64__) - g_cpuFamily = ANDROID_CPU_FAMILY_ARM64; -#elif defined(__x86_64__) - g_cpuFamily = ANDROID_CPU_FAMILY_X86_64; -#else - g_cpuFamily = ANDROID_CPU_FAMILY_UNKNOWN; -#endif -} - -static void -android_cpuInit(void) -{ - char* cpuinfo = NULL; - int cpuinfo_len; - - android_cpuInitFamily(); - - g_cpuFeatures = 0; - g_cpuCount = 1; - g_inited = 1; - - cpuinfo_len = get_file_size("/proc/cpuinfo"); - if (cpuinfo_len < 0) { - D("cpuinfo_len cannot be computed!"); - return; - } - cpuinfo = malloc(cpuinfo_len); - if (cpuinfo == NULL) { - D("cpuinfo buffer could not be allocated"); - return; - } - cpuinfo_len = read_file("/proc/cpuinfo", cpuinfo, cpuinfo_len); - D("cpuinfo_len is (%d):\n%.*s\n", cpuinfo_len, - cpuinfo_len >= 0 ? cpuinfo_len : 0, cpuinfo); - - if (cpuinfo_len < 0) /* should not happen */ { - free(cpuinfo); - return; - } - - /* Count the CPU cores, the value may be 0 for single-core CPUs */ - g_cpuCount = get_cpu_count(); - if (g_cpuCount == 0) { - g_cpuCount = 1; - } - - D("found cpuCount = %d\n", g_cpuCount); - -#ifdef __arm__ - { - char* features = NULL; - char* architecture = NULL; - - /* 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* cpuArch = extract_cpuinfo_field(cpuinfo, cpuinfo_len, "CPU architecture"); - - if (cpuArch != NULL) { - char* end; - long archNumber; - int hasARMv7 = 0; - - D("found cpuArch = '%s'\n", cpuArch); - - /* read the initial decimal number, ignore the rest */ - archNumber = strtol(cpuArch, &end, 10); - - /* Here we assume that ARMv8 will be upwards compatible with v7 - * in the future. Unfortunately, there is no 'Features' field to - * indicate that Thumb-2 is supported. - */ - if (end > cpuArch && archNumber >= 7) { - hasARMv7 = 1; - } - - /* 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_format' - * field reported by the 'Processor' field, which is of the - * form of "(v7l)" for an ARMv7-based CPU, and "(v6l)" for - * an ARMv6-one. - */ - if (hasARMv7) { - char* cpuProc = extract_cpuinfo_field(cpuinfo, cpuinfo_len, - "Processor"); - if (cpuProc != NULL) { - D("found cpuProc = '%s'\n", cpuProc); - if (has_list_item(cpuProc, "(v6l)")) { - D("CPU processor and architecture mismatch!!\n"); - hasARMv7 = 0; - } - free(cpuProc); - } - } - - if (hasARMv7) { - g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_ARMv7; - } - - /* The LDREX / STREX instructions are available from ARMv6 */ - if (archNumber >= 6) { - g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_LDREX_STREX; - } - - free(cpuArch); - } - - /* Extract the list of CPU features from ELF hwcaps */ - uint32_t hwcaps = get_elf_hwcap(cpuinfo, cpuinfo_len); - - if (hwcaps != 0) { - int has_vfp = (hwcaps & HWCAP_VFP); - int has_vfpv3 = (hwcaps & HWCAP_VFPv3); - int has_vfpv3d16 = (hwcaps & HWCAP_VFPv3D16); - int has_vfpv4 = (hwcaps & HWCAP_VFPv4); - int has_neon = (hwcaps & HWCAP_NEON); - int has_idiva = (hwcaps & HWCAP_IDIVA); - int has_idivt = (hwcaps & HWCAP_IDIVT); - int has_iwmmxt = (hwcaps & HWCAP_IWMMXT); - - // The kernel does a poor job at ensuring consistency when - // describing CPU features. So lots of guessing is needed. - - // 'vfpv4' implies VFPv3|VFP_FMA|FP16 - if (has_vfpv4) - g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_VFPv3 | - ANDROID_CPU_ARM_FEATURE_VFP_FP16 | - ANDROID_CPU_ARM_FEATURE_VFP_FMA; - - // 'vfpv3' or 'vfpv3d16' imply VFPv3. Note that unlike GCC, - // a value of 'vfpv3' doesn't necessarily mean that the D32 - // feature is present, so be conservative. All CPUs in the - // field that support D32 also support NEON, so this should - // not be a problem in practice. - if (has_vfpv3 || has_vfpv3d16) - g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_VFPv3; - - // 'vfp' is super ambiguous. Depending on the kernel, it can - // either mean VFPv2 or VFPv3. Make it depend on ARMv7. - if (has_vfp) { - if (g_cpuFeatures & ANDROID_CPU_ARM_FEATURE_ARMv7) - g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_VFPv3; - else - g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_VFPv2; - } - - // Neon implies VFPv3|D32, and if vfpv4 is detected, NEON_FMA - if (has_neon) { - g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_VFPv3 | - ANDROID_CPU_ARM_FEATURE_NEON | - ANDROID_CPU_ARM_FEATURE_VFP_D32; - if (has_vfpv4) - g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_NEON_FMA; - } - - // VFPv3 implies VFPv2 and ARMv7 - if (g_cpuFeatures & ANDROID_CPU_ARM_FEATURE_VFPv3) - g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_VFPv2 | - ANDROID_CPU_ARM_FEATURE_ARMv7; - - if (has_idiva) - g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_IDIV_ARM; - if (has_idivt) - g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_IDIV_THUMB2; - - if (has_iwmmxt) - g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_iWMMXt; - } - - /* Extract the cpuid value from various fields */ - // The CPUID value is broken up in several entries in /proc/cpuinfo. - // This table is used to rebuild it from the entries. - static const struct CpuIdEntry { - const char* field; - char format; - char bit_lshift; - char bit_length; - } cpu_id_entries[] = { - { "CPU implementer", 'x', 24, 8 }, - { "CPU variant", 'x', 20, 4 }, - { "CPU part", 'x', 4, 12 }, - { "CPU revision", 'd', 0, 4 }, - }; - size_t i; - D("Parsing /proc/cpuinfo to recover CPUID\n"); - for (i = 0; - i < sizeof(cpu_id_entries)/sizeof(cpu_id_entries[0]); - ++i) { - const struct CpuIdEntry* entry = &cpu_id_entries[i]; - char* value = extract_cpuinfo_field(cpuinfo, - cpuinfo_len, - entry->field); - if (value == NULL) - continue; - - D("field=%s value='%s'\n", entry->field, value); - char* value_end = value + strlen(value); - int val = 0; - const char* start = value; - const char* p; - if (value[0] == '0' && (value[1] == 'x' || value[1] == 'X')) { - start += 2; - p = parse_hexadecimal(start, value_end, &val); - } else if (entry->format == 'x') - p = parse_hexadecimal(value, value_end, &val); - else - p = parse_decimal(value, value_end, &val); - - if (p > (const char*)start) { - val &= ((1 << entry->bit_length)-1); - val <<= entry->bit_lshift; - g_cpuIdArm |= (uint32_t) val; - } - - free(value); - } - - // Handle kernel configuration bugs that prevent the correct - // reporting of CPU features. - static const struct CpuFix { - uint32_t cpuid; - uint64_t or_flags; - } cpu_fixes[] = { - /* The Nexus 4 (Qualcomm Krait) kernel configuration - * forgets to report IDIV support. */ - { 0x510006f2, ANDROID_CPU_ARM_FEATURE_IDIV_ARM | - ANDROID_CPU_ARM_FEATURE_IDIV_THUMB2 }, - { 0x510006f3, ANDROID_CPU_ARM_FEATURE_IDIV_ARM | - ANDROID_CPU_ARM_FEATURE_IDIV_THUMB2 }, - }; - size_t n; - for (n = 0; n < sizeof(cpu_fixes)/sizeof(cpu_fixes[0]); ++n) { - const struct CpuFix* entry = &cpu_fixes[n]; - - if (g_cpuIdArm == entry->cpuid) - g_cpuFeatures |= entry->or_flags; - } - - } -#endif /* __arm__ */ - -#ifdef __i386__ - int regs[4]; - -/* According to http://en.wikipedia.org/wiki/CPUID */ -#define VENDOR_INTEL_b 0x756e6547 -#define VENDOR_INTEL_c 0x6c65746e -#define VENDOR_INTEL_d 0x49656e69 - - x86_cpuid(0, regs); - int vendorIsIntel = (regs[1] == VENDOR_INTEL_b && - regs[2] == VENDOR_INTEL_c && - regs[3] == VENDOR_INTEL_d); - - x86_cpuid(1, regs); - if ((regs[2] & (1 << 9)) != 0) { - g_cpuFeatures |= ANDROID_CPU_X86_FEATURE_SSSE3; - } - if ((regs[2] & (1 << 23)) != 0) { - g_cpuFeatures |= ANDROID_CPU_X86_FEATURE_POPCNT; - } - if (vendorIsIntel && (regs[2] & (1 << 22)) != 0) { - g_cpuFeatures |= ANDROID_CPU_X86_FEATURE_MOVBE; - } -#endif - - free(cpuinfo); -} - - -AndroidCpuFamily -android_getCpuFamily(void) -{ - pthread_once(&g_once, android_cpuInit); - return g_cpuFamily; -} - - -uint64_t -android_getCpuFeatures(void) -{ - pthread_once(&g_once, android_cpuInit); - return g_cpuFeatures; -} - - -int -android_getCpuCount(void) -{ - pthread_once(&g_once, android_cpuInit); - return g_cpuCount; -} - -static void -android_cpuInitDummy(void) -{ - g_inited = 1; -} - -int -android_setCpu(int cpu_count, uint64_t cpu_features) -{ - /* Fail if the library was already initialized. */ - if (g_inited) - return 0; - - android_cpuInitFamily(); - g_cpuCount = (cpu_count <= 0 ? 1 : cpu_count); - g_cpuFeatures = cpu_features; - pthread_once(&g_once, android_cpuInitDummy); - - return 1; -} - -#ifdef __arm__ -uint32_t -android_getCpuIdArm(void) -{ - pthread_once(&g_once, android_cpuInit); - return g_cpuIdArm; -} - -int -android_setCpuArm(int cpu_count, uint64_t cpu_features, uint32_t cpu_id) -{ - if (!android_setCpu(cpu_count, cpu_features)) - return 0; - - g_cpuIdArm = cpu_id; - return 1; -} -#endif /* __arm__ */ - -/* - * Technical note: Making sense of ARM's FPU architecture versions. - * - * FPA was ARM's first attempt at an FPU architecture. There is no Android - * device that actually uses it since this technology was already obsolete - * when the project started. If you see references to FPA instructions - * somewhere, you can be sure that this doesn't apply to Android at all. - * - * FPA was followed by "VFP", soon renamed "VFPv1" due to the emergence of - * new versions / additions to it. ARM considers this obsolete right now, - * and no known Android device implements it either. - * - * VFPv2 added a few instructions to VFPv1, and is an *optional* extension - * supported by some ARMv5TE, ARMv6 and ARMv6T2 CPUs. Note that a device - * supporting the 'armeabi' ABI doesn't necessarily support these. - * - * VFPv3-D16 adds a few instructions on top of VFPv2 and is typically used - * on ARMv7-A CPUs which implement a FPU. Note that it is also mandated - * by the Android 'armeabi-v7a' ABI. The -D16 suffix in its name means - * that it provides 16 double-precision FPU registers (d0-d15) and 32 - * single-precision ones (s0-s31) which happen to be mapped to the same - * register banks. - * - * VFPv3-D32 is the name of an extension to VFPv3-D16 that provides 16 - * additional double precision registers (d16-d31). Note that there are - * still only 32 single precision registers. - * - * VFPv3xD is a *subset* of VFPv3-D16 that only provides single-precision - * registers. It is only used on ARMv7-M (i.e. on micro-controllers) which - * are not supported by Android. Note that it is not compatible with VFPv2. - * - * NOTE: The term 'VFPv3' usually designate either VFPv3-D16 or VFPv3-D32 - * depending on context. For example GCC uses it for VFPv3-D32, but - * the Linux kernel code uses it for VFPv3-D16 (especially in - * /proc/cpuinfo). Always try to use the full designation when - * possible. - * - * NEON, a.k.a. "ARM Advanced SIMD" is an extension that provides - * instructions to perform parallel computations on vectors of 8, 16, - * 32, 64 and 128 bit quantities. NEON requires VFPv32-D32 since all - * NEON registers are also mapped to the same register banks. - * - * VFPv4-D16, adds a few instructions on top of VFPv3-D16 in order to - * perform fused multiply-accumulate on VFP registers, as well as - * half-precision (16-bit) conversion operations. - * - * VFPv4-D32 is VFPv4-D16 with 32, instead of 16, FPU double precision - * registers. - * - * VPFv4-NEON is VFPv4-D32 with NEON instructions. It also adds fused - * multiply-accumulate instructions that work on the NEON registers. - * - * NOTE: Similarly, "VFPv4" might either reference VFPv4-D16 or VFPv4-D32 - * depending on context. - * - * The following information was determined by scanning the binutils-2.22 - * sources: - * - * Basic VFP instruction subsets: - * - * #define FPU_VFP_EXT_V1xD 0x08000000 // Base VFP instruction set. - * #define FPU_VFP_EXT_V1 0x04000000 // Double-precision insns. - * #define FPU_VFP_EXT_V2 0x02000000 // ARM10E VFPr1. - * #define FPU_VFP_EXT_V3xD 0x01000000 // VFPv3 single-precision. - * #define FPU_VFP_EXT_V3 0x00800000 // VFPv3 double-precision. - * #define FPU_NEON_EXT_V1 0x00400000 // Neon (SIMD) insns. - * #define FPU_VFP_EXT_D32 0x00200000 // Registers D16-D31. - * #define FPU_VFP_EXT_FP16 0x00100000 // Half-precision extensions. - * #define FPU_NEON_EXT_FMA 0x00080000 // Neon fused multiply-add - * #define FPU_VFP_EXT_FMA 0x00040000 // VFP fused multiply-add - * - * FPU types (excluding NEON) - * - * FPU_VFP_V1xD (EXT_V1xD) - * | - * +--------------------------+ - * | | - * FPU_VFP_V1 (+EXT_V1) FPU_VFP_V3xD (+EXT_V2+EXT_V3xD) - * | | - * | | - * FPU_VFP_V2 (+EXT_V2) FPU_VFP_V4_SP_D16 (+EXT_FP16+EXT_FMA) - * | - * FPU_VFP_V3D16 (+EXT_Vx3D+EXT_V3) - * | - * +--------------------------+ - * | | - * FPU_VFP_V3 (+EXT_D32) FPU_VFP_V4D16 (+EXT_FP16+EXT_FMA) - * | | - * | FPU_VFP_V4 (+EXT_D32) - * | - * FPU_VFP_HARD (+EXT_FMA+NEON_EXT_FMA) - * - * VFP architectures: - * - * ARCH_VFP_V1xD (EXT_V1xD) - * | - * +------------------+ - * | | - * | ARCH_VFP_V3xD (+EXT_V2+EXT_V3xD) - * | | - * | ARCH_VFP_V3xD_FP16 (+EXT_FP16) - * | | - * | ARCH_VFP_V4_SP_D16 (+EXT_FMA) - * | - * ARCH_VFP_V1 (+EXT_V1) - * | - * ARCH_VFP_V2 (+EXT_V2) - * | - * ARCH_VFP_V3D16 (+EXT_V3xD+EXT_V3) - * | - * +-------------------+ - * | | - * | ARCH_VFP_V3D16_FP16 (+EXT_FP16) - * | - * +-------------------+ - * | | - * | ARCH_VFP_V4_D16 (+EXT_FP16+EXT_FMA) - * | | - * | ARCH_VFP_V4 (+EXT_D32) - * | | - * | ARCH_NEON_VFP_V4 (+EXT_NEON+EXT_NEON_FMA) - * | - * ARCH_VFP_V3 (+EXT_D32) - * | - * +-------------------+ - * | | - * | ARCH_VFP_V3_FP16 (+EXT_FP16) - * | - * ARCH_VFP_V3_PLUS_NEON_V1 (+EXT_NEON) - * | - * ARCH_NEON_FP16 (+EXT_FP16) - * - * -fpu=<name> values and their correspondance with FPU architectures above: - * - * {"vfp", FPU_ARCH_VFP_V2}, - * {"vfp9", FPU_ARCH_VFP_V2}, - * {"vfp3", FPU_ARCH_VFP_V3}, // For backwards compatbility. - * {"vfp10", FPU_ARCH_VFP_V2}, - * {"vfp10-r0", FPU_ARCH_VFP_V1}, - * {"vfpxd", FPU_ARCH_VFP_V1xD}, - * {"vfpv2", FPU_ARCH_VFP_V2}, - * {"vfpv3", FPU_ARCH_VFP_V3}, - * {"vfpv3-fp16", FPU_ARCH_VFP_V3_FP16}, - * {"vfpv3-d16", FPU_ARCH_VFP_V3D16}, - * {"vfpv3-d16-fp16", FPU_ARCH_VFP_V3D16_FP16}, - * {"vfpv3xd", FPU_ARCH_VFP_V3xD}, - * {"vfpv3xd-fp16", FPU_ARCH_VFP_V3xD_FP16}, - * {"neon", FPU_ARCH_VFP_V3_PLUS_NEON_V1}, - * {"neon-fp16", FPU_ARCH_NEON_FP16}, - * {"vfpv4", FPU_ARCH_VFP_V4}, - * {"vfpv4-d16", FPU_ARCH_VFP_V4D16}, - * {"fpv4-sp-d16", FPU_ARCH_VFP_V4_SP_D16}, - * {"neon-vfpv4", FPU_ARCH_NEON_VFP_V4}, - * - * - * Simplified diagram that only includes FPUs supported by Android: - * Only ARCH_VFP_V3D16 is actually mandated by the armeabi-v7a ABI, - * all others are optional and must be probed at runtime. - * - * ARCH_VFP_V3D16 (EXT_V1xD+EXT_V1+EXT_V2+EXT_V3xD+EXT_V3) - * | - * +-------------------+ - * | | - * | ARCH_VFP_V3D16_FP16 (+EXT_FP16) - * | - * +-------------------+ - * | | - * | ARCH_VFP_V4_D16 (+EXT_FP16+EXT_FMA) - * | | - * | ARCH_VFP_V4 (+EXT_D32) - * | | - * | ARCH_NEON_VFP_V4 (+EXT_NEON+EXT_NEON_FMA) - * | - * ARCH_VFP_V3 (+EXT_D32) - * | - * +-------------------+ - * | | - * | ARCH_VFP_V3_FP16 (+EXT_FP16) - * | - * ARCH_VFP_V3_PLUS_NEON_V1 (+EXT_NEON) - * | - * ARCH_NEON_FP16 (+EXT_FP16) - * - */ - -#endif // defined(__le32__) |