/*
 * Copyright (C) 2020 Linux Studio Plugins Project <https://lsp-plug.in/>
 *           (C) 2020 Vladimir Sadovnikov <sadko4u@gmail.com>
 *
 * This file is part of lsp-dsp-lib
 * Created on: 31 мар. 2020 г.
 *
 * lsp-dsp-lib is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * any later version.
 *
 * lsp-dsp-lib is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with lsp-dsp-lib. If not, see <https://www.gnu.org/licenses/>.
 */

#include <lsp-plug.in/common/types.h>

#ifdef ARCH_AARCH64
    #include <private/dsp/exports.h>
    #include <lsp-plug.in/dsp/dsp.h>
    #include <lsp-plug.in/stdlib/string.h>
    #include <lsp-plug.in/stdlib/math.h>

    // Test framework
    #ifdef LSP_TESTING
        #include <lsp-plug.in/test-fw/test.h>
    #else
        #define TEST_EXPORT(...)
    #endif /* LSP_TESTING */

    #include <stdio.h>
    #include <errno.h>
    #include <stdlib.h>

    // Include common architectural definitions
    #define PRIVATE_DSP_ARCH_AARCH64_IMPL
        #include <private/dsp/arch/aarch64/features.h>
        #include <private/dsp/arch/aarch64/fpcr.h>
    #undef PRIVATE_DSP_ARCH_AARCH64_IMPL

namespace lsp
{
    namespace asimd
    {
        extern void dsp_init(const aarch64::cpu_features_t *f);
    }

    namespace aarch64
    {
        typedef struct cpu_part_t
        {
            uint32_t    id;
            const char *name;
        } cpu_part_t;

        typedef struct feature_t
        {
            uint32_t    mask;
            const char *name;
        } feature_t;

        static const cpu_part_t cpu_parts[] =
        {
            { 0xb02, "ARM11 MPCore" },
            { 0xb36, "ARM1136" },
            { 0xb56, "ARM1156" },
            { 0xb76, "ARM1176" },

            { 0xc05, "Cortex-A5" },
            { 0xc07, "Cortex-A7" },
            { 0xc08, "Cortex-A8" },
            { 0xc09, "Cortex-A9" },
            { 0xc0d, "Cortex-A12" },
            { 0xc0e, "Cortex-A17" },
            { 0xc0f, "Cortex-A15" },
            { 0xc14, "Cortex-R4" },
            { 0xc15, "Cortex-R5" },
            { 0xc17, "Cortex-R7" },
            { 0xc18, "Cortex-R8" },

            { 0xc20, "Cortex-M0" },
            { 0xc21, "Cortex-M1" },
            { 0xc23, "Cortex-M3" },
            { 0xc24, "Cortex-M4" },
            { 0xc27, "Cortex-M7" },
            { 0xc60, "Cortex-M0+" },

            { 0xd01, "Cortex-A32" },
            { 0xd03, "Cortex-A53" },
            { 0xd04, "Cortex-A35" },
            { 0xd05, "Cortex-A55" },
            { 0xd07, "Cortex-A57" },
            { 0xd08, "Cortex-A72" },
            { 0xd09, "Cortex-A73" },
            { 0xd0a, "Cortex-A75" },
            { 0xd13, "Cortex-R52" },

            { 0xd20, "Cortex-M23" },
            { 0xd21, "Cortex-M33" }
        };

        static const feature_t cpu_features[] =
        {
            { HWCAP_AARCH64_FP, "FP" },
            { HWCAP_AARCH64_ASIMD, "ASIMD" },
            { HWCAP_AARCH64_EVTSTRM, "EVTSTRM" },
            { HWCAP_AARCH64_AES, "AES" },
            { HWCAP_AARCH64_PMULL, "PMULL" },
            { HWCAP_AARCH64_SHA1, "SHA1" },
            { HWCAP_AARCH64_SHA2, "SHA2" },
            { HWCAP_AARCH64_CRC32, "CRC32" },
            { HWCAP_AARCH64_ATOMICS, "ATOMICS" },
            { HWCAP_AARCH64_FPHP, "FPHP" },
            { HWCAP_AARCH64_ASIMDHP, "ASIMDHP" },
            { HWCAP_AARCH64_CPUID, "CPUID" },
            { HWCAP_AARCH64_ASIMDRDM, "ASIMDRDM" },
            { HWCAP_AARCH64_JSCVT, "JSCVT" },
            { HWCAP_AARCH64_FCMA, "FCMA" },
            { HWCAP_AARCH64_LRCPC, "LSCPC" },
            { HWCAP_AARCH64_DCPOP, "DCPOP" },
            { HWCAP_AARCH64_SHA3, "SHA3" },
            { HWCAP_AARCH64_SM3, "SM3" },
            { HWCAP_AARCH64_SM4, "SM4" },
            { HWCAP_AARCH64_ASIMDDP, "ASMIDDP" },
            { HWCAP_AARCH64_SHA512, "SHA512" },
            { HWCAP_AARCH64_SVE, "SVE" },
            { HWCAP_AARCH64_ASIMDFHM, "ASIMDFHM" },
            { HWCAP_AARCH64_DIT, "DIT" },
            { HWCAP_AARCH64_USCAT, "USCAT" },
            { HWCAP_AARCH64_ILRCPC, "ILRCPC" },
            { HWCAP_AARCH64_FLAGM, "FLAGM" }
        };

        const char *find_cpu_name(uint32_t id)
        {
            ssize_t first = 0, last = (sizeof(cpu_parts) / sizeof(cpu_part_t)) - 1;
            while (first <= last)
            {
                ssize_t mid     = (first + last) >> 1;
                uint32_t xmid   = cpu_parts[mid].id;
                if (id < xmid)
                    last = mid - 1;
                else if (id > xmid)
                    first = mid + 1;
                else
                    return cpu_parts[mid].name;
            }
            return "Generic ARM processor";
        }

        void detect_cpu_features(cpu_features_t *f)  // must be at least 13 bytes
        {
            f->implementer      = 0;
            f->architecture     = 0;
            IF_ARCH_ARM6(f->architecture = 6);
            IF_ARCH_ARM7(f->architecture = 7);
            IF_ARCH_ARM8(f->architecture = 8);
            f->variant          = 0;
            f->part             = 0;
            f->revision         = 0;
            f->hwcap            = getauxval(AT_HWCAP);

    //        processor       : 0
    //        BogoMIPS        : 38.40
    //        Features        : fp asimd evtstrm crc32 cpuid
    //        CPU implementer : 0x41
    //        CPU architecture: 8
    //        CPU variant     : 0x0
    //        CPU part        : 0xd03
    //        CPU revision    : 4

            // Read /proc/cpuinfo
            FILE *cpuinfo = fopen("/proc/cpuinfo", "r");
            if (cpuinfo == NULL)
                return;  // handle error

            size_t size = 0;
            char *line  = NULL;

            while (getline(&line, &size, cpuinfo) >= 0)
            {
                size_t *field = NULL;

                // Find field
                if (strncasecmp(line, "CPU implementer", 15) == 0)
                    field = &f->implementer;
                else if (strncasecmp(line, "CPU architecture", 16) == 0)
                    field = &f->architecture;
                else if (strncasecmp(line, "CPU variant", 11) == 0)
                    field = &f->variant;
                else if (strncasecmp(line, "CPU part", 8) == 0)
                    field = &f->part;
                else if (strncasecmp(line, "CPU revision", 12) == 0)
                    field = &f->revision;

                if (field == NULL) // Field not found ?
                    continue;
                char *colon = strchr(line, ':'); // Colon not found ?
                if (colon++ == NULL)
                    continue;

                while ((*colon) == ' ')
                    colon++;
                if ((*colon) == '\0') // No data ?
                    continue;

                // Detect number base
                size_t base = 10;
                if (strncasecmp(colon, "0x", 2) == 0)
                {
                    colon  += 2;
                    base    = 16;
                }

                // Parse value
                errno       = 0;
                long value  = strtol(colon, &colon, base);
                if (errno != 0) // Failed parse ?
                    continue;
                if (((*colon) != '\0') && (*colon) != '\n') // Additional data?
                    continue;

                // Store parsed value
                *field      = value;
            }

            // if we got here, handle error
            if (line != NULL)
                free(line);
            fclose(cpuinfo);
        }

        static size_t estimate_features_size(const cpu_features_t *f)
        {
            // Estimate the string length
            size_t estimate = 1; // End of string character
            for (size_t i = 0, n=sizeof(cpu_features)/sizeof(feature_t); i < n; i++)
            {
                if (!(f->hwcap & cpu_features[i].mask))
                    continue;

                if (estimate > 0)
                    estimate++;
                estimate += strlen(cpu_features[i].name);
            }
            return estimate;
        }

        static char *build_features_list(char *dst, const cpu_features_t *f)
        {
            // Build string
            char *s = dst;

            for (size_t i = 0, n=sizeof(cpu_features)/sizeof(feature_t); i < n; i++)
            {
                if (!(f->hwcap & cpu_features[i].mask))
                    continue;
                if (s != dst)
                    s = stpcpy(s, " ");
                s = stpcpy(s, cpu_features[i].name);
            }
            *s = '\0';

            return s;
        }

        dsp::info_t *info()
        {
            cpu_features_t f;
            detect_cpu_features(&f);

            const char *cpu = find_cpu_name(f.part);
            char *model     = NULL;
            int n = asprintf(&model, "vendor=0x%x, architecture=%d, variant=%d, part=0x%x, revision=%d",
                    int(f.implementer), int(f.architecture), int(f.variant), int(f.part), int(f.revision));
            if ((n < 0) || (model == NULL))
                return NULL;

            size_t size     = sizeof(dsp::info_t);
            size           += strlen(ARCH_STRING) + 1;
            size           += strlen(cpu) + 1;
            size           += strlen(model) + 1;
            size           += estimate_features_size(&f);

            dsp::info_t *res = reinterpret_cast<dsp::info_t *>(malloc(size));
            if (res == NULL)
            {
                free(model);
                return res;
            }

            char *text      = reinterpret_cast<char *>(&res[1]);
            res->arch       = text;
            text            = stpcpy(text, ARCH_STRING) + 1;
            res->cpu        = text;
            text            = stpcpy(text, cpu) + 1;
            res->model      = text;
            text            = stpcpy(text, model) + 1;
            res->features   = text;
            build_features_list(text, &f);

            free(model);
            return res;
        }

        #define EXPORT2(function, export) \
        { \
            dsp::function                       = aarch64::export; \
            dsp::LSP_DSP_LIB_MANGLE(function)   = aarch64::export; \
            TEST_EXPORT(aarch64::export); \
        }
        #define EXPORT1(function)                   EXPORT2(function, function)

        void dsp_init()
        {
            cpu_features_t f;
            detect_cpu_features(&f);

            // Export functions
            EXPORT1(info);

            // Initialize Advanced SIMD support
            asimd::dsp_init(&f);
        }
    }
}

#endif /* ARCH_AARCH64 */


