diff options
Diffstat (limited to 'drivers/theoraplayer/src/YUV/android/cpu-features.c')
| -rw-r--r-- | drivers/theoraplayer/src/YUV/android/cpu-features.c | 1095 |
1 files changed, 1095 insertions, 0 deletions
diff --git a/drivers/theoraplayer/src/YUV/android/cpu-features.c b/drivers/theoraplayer/src/YUV/android/cpu-features.c new file mode 100644 index 0000000000..623dc94e0e --- /dev/null +++ b/drivers/theoraplayer/src/YUV/android/cpu-features.c @@ -0,0 +1,1095 @@ +/* + * 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 0 + +#ifdef _ANDROID +#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, ret, 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_getCpuFeaturesExt(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__) +#endif + +#endif |