// SPDX-FileCopyrightText: 2017 Google Inc.
// SPDX-License-Identifier: Apache-2.0

#include "cpuinfo_mips.h"
#include "internal/filesystem.h"
#include "internal/stack_line_reader.h"
#include "internal/string_view.h"
#include "internal/unix_features_aggregator.h"
#include <assert.h>

DECLARE_SETTER_AND_GETTER(MipsFeatures, msa)
DECLARE_SETTER_AND_GETTER(MipsFeatures, eva)
DECLARE_SETTER_AND_GETTER(MipsFeatures, r6)

static const CapabilityConfig kConfigs[] = {
    [MIPS_MSA] = {{MIPS_HWCAP_MSA, 0}, "msa", &set_msa, &get_msa},  //
    [MIPS_EVA] = {{0, 0}, "eva", &set_eva, &get_eva},               //
    [MIPS_R6] = {{MIPS_HWCAP_R6, 0}, "r6", &set_r6, &get_r6},       //
};
static const size_t kConfigsSize = sizeof(kConfigs) / sizeof(CapabilityConfig);

static bool HandleMipsLine(const LineResult result,
    MipsFeatures* const features)
{
    StringView key, value;
    // See tests for an example.
    if (CpuFeatures_StringView_GetAttributeKeyValue(result.line, &key, &value))
        {
            if (CpuFeatures_StringView_IsEquals(key, str("ASEs implemented")))
                {
                    CpuFeatures_SetFromFlags(kConfigsSize, kConfigs, value, features);
                }
        }
    return !result.eof;
}

static void FillProcCpuInfoData(MipsFeatures* const features)
{
    const int fd = CpuFeatures_OpenFile("/proc/cpuinfo");
    if (fd >= 0)
        {
            StackLineReader reader;
            StackLineReader_Initialize(&reader, fd);
            for (;;)
                {
                    if (!HandleMipsLine(StackLineReader_NextLine(&reader), features))
                        {
                            break;
                        }
                }
            CpuFeatures_CloseFile(fd);
        }
}

static const MipsInfo kEmptyMipsInfo;

MipsInfo GetMipsInfo(void)
{
    assert(kConfigsSize == MIPS_LAST_);

    // capabilities are fetched from both getauxval and /proc/cpuinfo so we can
    // have some information if the executable is sandboxed (aka no access to
    // /proc/cpuinfo).
    MipsInfo info = kEmptyMipsInfo;

    FillProcCpuInfoData(&info.features);
    CpuFeatures_OverrideFromHwCaps(kConfigsSize, kConfigs,
        CpuFeatures_GetHardwareCapabilities(),
        &info.features);
    return info;
}

////////////////////////////////////////////////////////////////////////////////
// Introspection functions

int GetMipsFeaturesEnumValue(const MipsFeatures* features,
    MipsFeaturesEnum value)
{
    if (value >= kConfigsSize)
        return false;
    return kConfigs[value].get_bit((MipsFeatures*)features);
}

const char* GetMipsFeaturesEnumName(MipsFeaturesEnum value)
{
    if (value >= kConfigsSize)
        return "unknown feature";
    return kConfigs[value].proc_cpuinfo_flag;
}