// SPDX-License-Identifier: GPL-2.0-only
/*
 *  (C) 2010,2011       Thomas Renninger <trenn@suse.de>, Novell Inc.
 *
 *  Based on Len Brown's <lenb@kernel.org> turbostat tool.
 */

#if defined(__i386__) || defined(__x86_64__)

#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>

#include "helpers/helpers.h"
#include "idle_monitor/cpupower-monitor.h"

#define MSR_PKG_C3_RESIDENCY    0x3F8
#define MSR_PKG_C6_RESIDENCY    0x3F9
#define MSR_CORE_C3_RESIDENCY   0x3FC
#define MSR_CORE_C6_RESIDENCY   0x3FD

#define MSR_TSC 0x10

#define NHM_CSTATE_COUNT 4

enum intel_nhm_id { C3 = 0, C6, PC3, PC6, TSC = 0xFFFF };

static int nhm_get_count_percent(unsigned int self_id, double *percent,
                                 unsigned int cpu);

static cstate_t nhm_cstates[NHM_CSTATE_COUNT] = {
        {
                .name                   = "C3",
                .desc                   = N_("Processor Core C3"),
                .id                     = C3,
                .range                  = RANGE_CORE,
                .get_count_percent      = nhm_get_count_percent,
        },
        {
                .name                   = "C6",
                .desc                   = N_("Processor Core C6"),
                .id                     = C6,
                .range                  = RANGE_CORE,
                .get_count_percent      = nhm_get_count_percent,
        },

        {
                .name                   = "PC3",
                .desc                   = N_("Processor Package C3"),
                .id                     = PC3,
                .range                  = RANGE_PACKAGE,
                .get_count_percent      = nhm_get_count_percent,
        },
        {
                .name                   = "PC6",
                .desc                   = N_("Processor Package C6"),
                .id                     = PC6,
                .range                  = RANGE_PACKAGE,
                .get_count_percent      = nhm_get_count_percent,
        },
};

static unsigned long long tsc_at_measure_start;
static unsigned long long tsc_at_measure_end;
static unsigned long long *previous_count[NHM_CSTATE_COUNT];
static unsigned long long *current_count[NHM_CSTATE_COUNT];
/* valid flag for all CPUs. If a MSR read failed it will be zero */
static int *is_valid;

static int nhm_get_count(enum intel_nhm_id id, unsigned long long *val,
                        unsigned int cpu)
{
        int msr;

        switch (id) {
        case C3:
                msr = MSR_CORE_C3_RESIDENCY;
                break;
        case C6:
                msr = MSR_CORE_C6_RESIDENCY;
                break;
        case PC3:
                msr = MSR_PKG_C3_RESIDENCY;
                break;
        case PC6:
                msr = MSR_PKG_C6_RESIDENCY;
                break;
        case TSC:
                msr = MSR_TSC;
                break;
        default:
                return -1;
        }
        if (read_msr(cpu, msr, val))
                return -1;

        return 0;
}

static int nhm_get_count_percent(unsigned int id, double *percent,
                                 unsigned int cpu)
{
        *percent = 0.0;

        if (!is_valid[cpu])
                return -1;

        *percent = (100.0 *
                (current_count[id][cpu] - previous_count[id][cpu])) /
                (tsc_at_measure_end - tsc_at_measure_start);

        dprint("%s: previous: %llu - current: %llu - (%u)\n",
                nhm_cstates[id].name, previous_count[id][cpu],
                current_count[id][cpu], cpu);

        dprint("%s: tsc_diff: %llu - count_diff: %llu - percent: %2.f (%u)\n",
               nhm_cstates[id].name,
               (unsigned long long) tsc_at_measure_end - tsc_at_measure_start,
               current_count[id][cpu] - previous_count[id][cpu],
               *percent, cpu);

        return 0;
}

static int nhm_start(void)
{
        int num, cpu;
        unsigned long long dbg, val;

        nhm_get_count(TSC, &tsc_at_measure_start, base_cpu);

        for (num = 0; num < NHM_CSTATE_COUNT; num++) {
                for (cpu = 0; cpu < cpu_count; cpu++) {
                        is_valid[cpu] = !nhm_get_count(num, &val, cpu);
                        previous_count[num][cpu] = val;
                }
        }
        nhm_get_count(TSC, &dbg, base_cpu);
        dprint("TSC diff: %llu\n", dbg - tsc_at_measure_start);
        return 0;
}

static int nhm_stop(void)
{
        unsigned long long val;
        unsigned long long dbg;
        int num, cpu;

        nhm_get_count(TSC, &tsc_at_measure_end, base_cpu);

        for (num = 0; num < NHM_CSTATE_COUNT; num++) {
                for (cpu = 0; cpu < cpu_count; cpu++) {
                        is_valid[cpu] |= !nhm_get_count(num, &val, cpu);
                        current_count[num][cpu] = val;
                }
        }
        nhm_get_count(TSC, &dbg, base_cpu);
        dprint("TSC diff: %llu\n", dbg - tsc_at_measure_end);

        return 0;
}

struct cpuidle_monitor intel_nhm_monitor;

struct cpuidle_monitor *intel_nhm_register(void)
{
        int num;

        if (cpupower_cpu_info.vendor != X86_VENDOR_INTEL)
                return NULL;

        if (!(cpupower_cpu_info.caps & CPUPOWER_CAP_INV_TSC))
                return NULL;

        if (!(cpupower_cpu_info.caps & CPUPOWER_CAP_APERF))
                return NULL;

        /* Free this at program termination */
        is_valid = calloc(cpu_count, sizeof(int));
        for (num = 0; num < NHM_CSTATE_COUNT; num++) {
                previous_count[num] = calloc(cpu_count,
                                        sizeof(unsigned long long));
                current_count[num]  = calloc(cpu_count,
                                        sizeof(unsigned long long));
        }

        intel_nhm_monitor.name_len = strlen(intel_nhm_monitor.name);
        return &intel_nhm_monitor;
}

void intel_nhm_unregister(void)
{
        int num;

        for (num = 0; num < NHM_CSTATE_COUNT; num++) {
                free(previous_count[num]);
                free(current_count[num]);
        }
        free(is_valid);
}

struct cpuidle_monitor intel_nhm_monitor = {
        .name                   = "Nehalem",
        .hw_states_num          = NHM_CSTATE_COUNT,
        .hw_states              = nhm_cstates,
        .start                  = nhm_start,
        .stop                   = nhm_stop,
        .do_register            = intel_nhm_register,
        .unregister             = intel_nhm_unregister,
        .flags.needs_root       = 1,
        .overflow_s             = 922000000 /* 922337203 seconds TSC overflow
                                               at 20GHz */
};
#endif