/*
 * SPDX-FileCopyrightText: 2010 The Android Open Source Project
 * SPDX-License-Identifier: BSD-2-Clause
 */

#include "cpu-features.h"
#include "cpu_features_macros.h"
#include "internal/filesystem.h"
#include "internal/stack_line_reader.h"
#include "internal/string_view.h"
#include <pthread.h>

#if defined(CPU_FEATURES_ARCH_ARM)
#include "cpuinfo_arm.h"
#elif defined(CPU_FEATURES_ARCH_X86)
#include "cpuinfo_x86.h"
#elif defined(CPU_FEATURES_ARCH_MIPS)
#include "cpuinfo_mips.h"
#elif defined(CPU_FEATURES_ARCH_AARCH64)
#include "cpuinfo_aarch64.h"
#endif

static pthread_once_t g_once;
static int g_inited;
static uint64_t g_cpuFeatures;
static int g_cpuCount;

#ifdef CPU_FEATURES_ARCH_ARM
static uint32_t g_cpuIdArm;
#endif

static void set_cpu_mask_bit(uint32_t index, uint32_t* cpu_mask)
{
    *cpu_mask |= 1UL << index;
}

// Examples of valid inputs: "31", "4-31"
static void parse_cpu_mask(const StringView text, uint32_t* cpu_mask)
{
    int separator_index = CpuFeatures_StringView_IndexOfChar(text, '-');
    if (separator_index < 0)
        {  // A single cpu index
            int cpu_index = CpuFeatures_StringView_ParsePositiveNumber(text);
            if (cpu_index < 0) return;
            set_cpu_mask_bit(cpu_index, cpu_mask);
        }
    else
        {
            int cpu_index_a = CpuFeatures_StringView_ParsePositiveNumber(
                CpuFeatures_StringView_KeepFront(text, separator_index));
            int cpu_index_b = CpuFeatures_StringView_ParsePositiveNumber(
                CpuFeatures_StringView_PopFront(text, separator_index + 1));
            int i;
            if (cpu_index_a < 0 || cpu_index_b < 0) return;
            for (i = cpu_index_a; i <= cpu_index_b; ++i)
                {
                    if (i < 32)
                        {
                            set_cpu_mask_bit(i, cpu_mask);
                        }
                }
        }
}

// Format specification from
// https://www.kernel.org/doc/Documentation/cputopology.txt
// Examples of valid inputs: "31", "2,4-31,32-63", "0-1,3"
static void parse_cpu_mask_line(const LineResult result, uint32_t* cpu_mask)
{
    if (!result.full_line || result.eof) return;
    StringView line = result.line;
    for (; line.size > 0;)
        {
            int next_entry_index = CpuFeatures_StringView_IndexOfChar(line, ',');
            if (next_entry_index < 0)
                {
                    parse_cpu_mask(line, cpu_mask);
                    break;
                }
            StringView entry = CpuFeatures_StringView_KeepFront(line, next_entry_index);
            parse_cpu_mask(entry, cpu_mask);
            line = CpuFeatures_StringView_PopFront(line, next_entry_index + 1);
        }
}

static void update_cpu_mask_from_file(const char* filename,
    uint32_t* cpu_mask)
{
    const int fd = CpuFeatures_OpenFile(filename);
    if (fd >= 0)
        {
            StackLineReader reader;
            StackLineReader_Initialize(&reader, fd);
            parse_cpu_mask_line(StackLineReader_NextLine(&reader), cpu_mask);
            CpuFeatures_CloseFile(fd);
        }
}

static int get_cpu_count(void)
{
    uint32_t cpu_mask = 0;
    update_cpu_mask_from_file("/sys/devices/system/cpu/present", &cpu_mask);
    update_cpu_mask_from_file("/sys/devices/system/cpu/possible", &cpu_mask);
    return __builtin_popcount(cpu_mask);
}

static void android_cpuInit(void)
{
    g_cpuFeatures = 0;
    g_cpuCount = 1;
    g_inited = 1;

    g_cpuCount = get_cpu_count();
    if (g_cpuCount == 0)
        {
            g_cpuCount = 1;
        }
#if defined(CPU_FEATURES_ARCH_ARM)
    ArmInfo info = GetArmInfo();
    if (info.architecture == 7) g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_ARMv7;
    if (info.features.vfpv3) g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_VFPv3;
    if (info.features.neon)
        {
            g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_NEON;
            g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_VFP_D32;
        }
    if (info.features.vfpv3d16) g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_VFP_FP16;
    if (info.features.idiva) g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_IDIV_ARM;
    if (info.features.idivt) g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_IDIV_THUMB2;
    if (info.features.iwmmxt) g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_iWMMXt;
    if (info.features.aes) g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_AES;
    if (info.features.pmull) g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_PMULL;
    if (info.features.sha1) g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_SHA1;
    if (info.features.sha2) g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_SHA2;
    if (info.features.crc32) g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_CRC32;
    if (info.architecture >= 6)
        g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_LDREX_STREX;
    if (info.features.vfp) g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_VFPv2;
    if (info.features.vfpv4)
        {
            g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_VFP_FMA;
            g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_NEON_FMA;
        }
    g_cpuIdArm = GetArmCpuId(&info);
#elif defined(CPU_FEATURES_ARCH_X86)
    X86Info info = GetX86Info();
    if (info.features.ssse3) g_cpuFeatures |= ANDROID_CPU_X86_FEATURE_SSSE3;
    if (info.features.popcnt) g_cpuFeatures |= ANDROID_CPU_X86_FEATURE_POPCNT;
    if (info.features.movbe) g_cpuFeatures |= ANDROID_CPU_X86_FEATURE_MOVBE;
    if (info.features.sse4_1) g_cpuFeatures |= ANDROID_CPU_X86_FEATURE_SSE4_1;
    if (info.features.sse4_2) g_cpuFeatures |= ANDROID_CPU_X86_FEATURE_SSE4_2;
    if (info.features.aes) g_cpuFeatures |= ANDROID_CPU_X86_FEATURE_AES_NI;
    if (info.features.avx) g_cpuFeatures |= ANDROID_CPU_X86_FEATURE_AVX;
    if (info.features.rdrnd) g_cpuFeatures |= ANDROID_CPU_X86_FEATURE_RDRAND;
    if (info.features.avx2) g_cpuFeatures |= ANDROID_CPU_X86_FEATURE_AVX2;
    if (info.features.sha) g_cpuFeatures |= ANDROID_CPU_X86_FEATURE_SHA_NI;
#elif defined(CPU_FEATURES_ARCH_MIPS)
    MipsInfo info = GetMipsInfo();
    if (info.features.r6) g_cpuFeatures |= ANDROID_CPU_MIPS_FEATURE_R6;
    if (info.features.msa) g_cpuFeatures |= ANDROID_CPU_MIPS_FEATURE_MSA;
#elif defined(CPU_FEATURES_ARCH_AARCH64)
    Aarch64Info info = GetAarch64Info();
    if (info.features.fp) g_cpuFeatures |= ANDROID_CPU_ARM64_FEATURE_FP;
    if (info.features.asimd) g_cpuFeatures |= ANDROID_CPU_ARM64_FEATURE_ASIMD;
    if (info.features.aes) g_cpuFeatures |= ANDROID_CPU_ARM64_FEATURE_AES;
    if (info.features.pmull) g_cpuFeatures |= ANDROID_CPU_ARM64_FEATURE_PMULL;
    if (info.features.sha1) g_cpuFeatures |= ANDROID_CPU_ARM64_FEATURE_SHA1;
    if (info.features.sha2) g_cpuFeatures |= ANDROID_CPU_ARM64_FEATURE_SHA2;
    if (info.features.crc32) g_cpuFeatures |= ANDROID_CPU_ARM64_FEATURE_CRC32;
#endif
}

AndroidCpuFamily android_getCpuFamily(void)
{
#if defined(CPU_FEATURES_ARCH_ARM)
    return ANDROID_CPU_FAMILY_ARM;
#elif defined(CPU_FEATURES_ARCH_X86_32)
    return ANDROID_CPU_FAMILY_X86;
#elif defined(CPU_FEATURES_ARCH_MIPS64)
    return ANDROID_CPU_FAMILY_MIPS64;
#elif defined(CPU_FEATURES_ARCH_MIPS32)
    return ANDROID_CPU_FAMILY_MIPS;
#elif defined(CPU_FEATURES_ARCH_AARCH64)
    return ANDROID_CPU_FAMILY_ARM64;
#elif defined(CPU_FEATURES_ARCH_X86_64)
    return ANDROID_CPU_FAMILY_X86_64;
#else
    return ANDROID_CPU_FAMILY_UNKNOWN;
#endif
}

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;
    g_cpuCount = (cpu_count <= 0 ? 1 : cpu_count);
    g_cpuFeatures = cpu_features;
    pthread_once(&g_once, android_cpuInitDummy);
    return 1;
}

#ifdef CPU_FEATURES_ARCH_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  // CPU_FEATURES_ARCH_ARM