// SPDX-License-Identifier: GPL-2.0
#include <api/fs/fs.h>
#include "../perf.h"
#include "cpumap.h"
#include <assert.h>
#include <dirent.h>
#include <stdio.h>
#include <stdlib.h>
#include <linux/bitmap.h>
#include "asm/bug.h"

#include <linux/ctype.h>
#include <linux/zalloc.h>

static int max_cpu_num;
static int max_present_cpu_num;
static int max_node_num;
static int *cpunode_map;

static struct cpu_map *cpu_map__default_new(void)
{
        struct cpu_map *cpus;
        int nr_cpus;

        nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
        if (nr_cpus < 0)
                return NULL;

        cpus = malloc(sizeof(*cpus) + nr_cpus * sizeof(int));
        if (cpus != NULL) {
                int i;
                for (i = 0; i < nr_cpus; ++i)
                        cpus->map[i] = i;

                cpus->nr = nr_cpus;
                refcount_set(&cpus->refcnt, 1);
        }

        return cpus;
}

static struct cpu_map *cpu_map__trim_new(int nr_cpus, int *tmp_cpus)
{
        size_t payload_size = nr_cpus * sizeof(int);
        struct cpu_map *cpus = malloc(sizeof(*cpus) + payload_size);

        if (cpus != NULL) {
                cpus->nr = nr_cpus;
                memcpy(cpus->map, tmp_cpus, payload_size);
                refcount_set(&cpus->refcnt, 1);
        }

        return cpus;
}

struct cpu_map *cpu_map__read(FILE *file)
{
        struct cpu_map *cpus = NULL;
        int nr_cpus = 0;
        int *tmp_cpus = NULL, *tmp;
        int max_entries = 0;
        int n, cpu, prev;
        char sep;

        sep = 0;
        prev = -1;
        for (;;) {
                n = fscanf(file, "%u%c", &cpu, &sep);
                if (n <= 0)
                        break;
                if (prev >= 0) {
                        int new_max = nr_cpus + cpu - prev - 1;

                        if (new_max >= max_entries) {
                                max_entries = new_max + MAX_NR_CPUS / 2;
                                tmp = realloc(tmp_cpus, max_entries * sizeof(int));
                                if (tmp == NULL)
                                        goto out_free_tmp;
                                tmp_cpus = tmp;
                        }

                        while (++prev < cpu)
                                tmp_cpus[nr_cpus++] = prev;
                }
                if (nr_cpus == max_entries) {
                        max_entries += MAX_NR_CPUS;
                        tmp = realloc(tmp_cpus, max_entries * sizeof(int));
                        if (tmp == NULL)
                                goto out_free_tmp;
                        tmp_cpus = tmp;
                }

                tmp_cpus[nr_cpus++] = cpu;
                if (n == 2 && sep == '-')
                        prev = cpu;
                else
                        prev = -1;
                if (n == 1 || sep == '\n')
                        break;
        }

        if (nr_cpus > 0)
                cpus = cpu_map__trim_new(nr_cpus, tmp_cpus);
        else
                cpus = cpu_map__default_new();
out_free_tmp:
        free(tmp_cpus);
        return cpus;
}

static struct cpu_map *cpu_map__read_all_cpu_map(void)
{
        struct cpu_map *cpus = NULL;
        FILE *onlnf;

        onlnf = fopen("/sys/devices/system/cpu/online", "r");
        if (!onlnf)
                return cpu_map__default_new();

        cpus = cpu_map__read(onlnf);
        fclose(onlnf);
        return cpus;
}

struct cpu_map *cpu_map__new(const char *cpu_list)
{
        struct cpu_map *cpus = NULL;
        unsigned long start_cpu, end_cpu = 0;
        char *p = NULL;
        int i, nr_cpus = 0;
        int *tmp_cpus = NULL, *tmp;
        int max_entries = 0;

        if (!cpu_list)
                return cpu_map__read_all_cpu_map();

        /*
         * must handle the case of empty cpumap to cover
         * TOPOLOGY header for NUMA nodes with no CPU
         * ( e.g., because of CPU hotplug)
         */
        if (!isdigit(*cpu_list) && *cpu_list != '\0')
                goto out;

        while (isdigit(*cpu_list)) {
                p = NULL;
                start_cpu = strtoul(cpu_list, &p, 0);
                if (start_cpu >= INT_MAX
                    || (*p != '\0' && *p != ',' && *p != '-'))
                        goto invalid;

                if (*p == '-') {
                        cpu_list = ++p;
                        p = NULL;
                        end_cpu = strtoul(cpu_list, &p, 0);

                        if (end_cpu >= INT_MAX || (*p != '\0' && *p != ','))
                                goto invalid;

                        if (end_cpu < start_cpu)
                                goto invalid;
                } else {
                        end_cpu = start_cpu;
                }

                for (; start_cpu <= end_cpu; start_cpu++) {
                        /* check for duplicates */
                        for (i = 0; i < nr_cpus; i++)
                                if (tmp_cpus[i] == (int)start_cpu)
                                        goto invalid;

                        if (nr_cpus == max_entries) {
                                max_entries += MAX_NR_CPUS;
                                tmp = realloc(tmp_cpus, max_entries * sizeof(int));
                                if (tmp == NULL)
                                        goto invalid;
                                tmp_cpus = tmp;
                        }
                        tmp_cpus[nr_cpus++] = (int)start_cpu;
                }
                if (*p)
                        ++p;

                cpu_list = p;
        }

        if (nr_cpus > 0)
                cpus = cpu_map__trim_new(nr_cpus, tmp_cpus);
        else if (*cpu_list != '\0')
                cpus = cpu_map__default_new();
        else
                cpus = cpu_map__dummy_new();
invalid:
        free(tmp_cpus);
out:
        return cpus;
}

static struct cpu_map *cpu_map__from_entries(struct cpu_map_entries *cpus)
{
        struct cpu_map *map;

        map = cpu_map__empty_new(cpus->nr);
        if (map) {
                unsigned i;

                for (i = 0; i < cpus->nr; i++) {
                        /*
                         * Special treatment for -1, which is not real cpu number,
                         * and we need to use (int) -1 to initialize map[i],
                         * otherwise it would become 65535.
                         */
                        if (cpus->cpu[i] == (u16) -1)
                                map->map[i] = -1;
                        else
                                map->map[i] = (int) cpus->cpu[i];
                }
        }

        return map;
}

static struct cpu_map *cpu_map__from_mask(struct cpu_map_mask *mask)
{
        struct cpu_map *map;
        int nr, nbits = mask->nr * mask->long_size * BITS_PER_BYTE;

        nr = bitmap_weight(mask->mask, nbits);

        map = cpu_map__empty_new(nr);
        if (map) {
                int cpu, i = 0;

                for_each_set_bit(cpu, mask->mask, nbits)
                        map->map[i++] = cpu;
        }
        return map;

}

struct cpu_map *cpu_map__new_data(struct cpu_map_data *data)
{
        if (data->type == PERF_CPU_MAP__CPUS)
                return cpu_map__from_entries((struct cpu_map_entries *)data->data);
        else
                return cpu_map__from_mask((struct cpu_map_mask *)data->data);
}

size_t cpu_map__fprintf(struct cpu_map *map, FILE *fp)
{
#define BUFSIZE 1024
        char buf[BUFSIZE];

        cpu_map__snprint(map, buf, sizeof(buf));
        return fprintf(fp, "%s\n", buf);
#undef BUFSIZE
}

struct cpu_map *cpu_map__dummy_new(void)
{
        struct cpu_map *cpus = malloc(sizeof(*cpus) + sizeof(int));

        if (cpus != NULL) {
                cpus->nr = 1;
                cpus->map[0] = -1;
                refcount_set(&cpus->refcnt, 1);
        }

        return cpus;
}

struct cpu_map *cpu_map__empty_new(int nr)
{
        struct cpu_map *cpus = malloc(sizeof(*cpus) + sizeof(int) * nr);

        if (cpus != NULL) {
                int i;

                cpus->nr = nr;
                for (i = 0; i < nr; i++)
                        cpus->map[i] = -1;

                refcount_set(&cpus->refcnt, 1);
        }

        return cpus;
}

static void cpu_map__delete(struct cpu_map *map)
{
        if (map) {
                WARN_ONCE(refcount_read(&map->refcnt) != 0,
                          "cpu_map refcnt unbalanced\n");
                free(map);
        }
}

struct cpu_map *cpu_map__get(struct cpu_map *map)
{
        if (map)
                refcount_inc(&map->refcnt);
        return map;
}

void cpu_map__put(struct cpu_map *map)
{
        if (map && refcount_dec_and_test(&map->refcnt))
                cpu_map__delete(map);
}

static int cpu__get_topology_int(int cpu, const char *name, int *value)
{
        char path[PATH_MAX];

        snprintf(path, PATH_MAX,
                "devices/system/cpu/cpu%d/topology/%s", cpu, name);

        return sysfs__read_int(path, value);
}

int cpu_map__get_socket_id(int cpu)
{
        int value, ret = cpu__get_topology_int(cpu, "physical_package_id", &value);
        return ret ?: value;
}

int cpu_map__get_socket(struct cpu_map *map, int idx, void *data __maybe_unused)
{
        int cpu;

        if (idx > map->nr)
                return -1;

        cpu = map->map[idx];

        return cpu_map__get_socket_id(cpu);
}

static int cmp_ids(const void *a, const void *b)
{
        return *(int *)a - *(int *)b;
}

int cpu_map__build_map(struct cpu_map *cpus, struct cpu_map **res,
                       int (*f)(struct cpu_map *map, int cpu, void *data),
                       void *data)
{
        struct cpu_map *c;
        int nr = cpus->nr;
        int cpu, s1, s2;

        /* allocate as much as possible */
        c = calloc(1, sizeof(*c) + nr * sizeof(int));
        if (!c)
                return -1;

        for (cpu = 0; cpu < nr; cpu++) {
                s1 = f(cpus, cpu, data);
                for (s2 = 0; s2 < c->nr; s2++) {
                        if (s1 == c->map[s2])
                                break;
                }
                if (s2 == c->nr) {
                        c->map[c->nr] = s1;
                        c->nr++;
                }
        }
        /* ensure we process id in increasing order */
        qsort(c->map, c->nr, sizeof(int), cmp_ids);

        refcount_set(&c->refcnt, 1);
        *res = c;
        return 0;
}

int cpu_map__get_die_id(int cpu)
{
        int value, ret = cpu__get_topology_int(cpu, "die_id", &value);

        return ret ?: value;
}

int cpu_map__get_die(struct cpu_map *map, int idx, void *data)
{
        int cpu, die_id, s;

        if (idx > map->nr)
                return -1;

        cpu = map->map[idx];

        die_id = cpu_map__get_die_id(cpu);
        /* There is no die_id on legacy system. */
        if (die_id == -1)
                die_id = 0;

        s = cpu_map__get_socket(map, idx, data);
        if (s == -1)
                return -1;

        /*
         * Encode socket in bit range 15:8
         * die_id is relative to socket, and
         * we need a global id. So we combine
         * socket + die id
         */
        if (WARN_ONCE(die_id >> 8, "The die id number is too big.\n"))
                return -1;

        if (WARN_ONCE(s >> 8, "The socket id number is too big.\n"))
                return -1;

        return (s << 8) | (die_id & 0xff);
}

int cpu_map__get_core_id(int cpu)
{
        int value, ret = cpu__get_topology_int(cpu, "core_id", &value);
        return ret ?: value;
}

int cpu_map__get_core(struct cpu_map *map, int idx, void *data)
{
        int cpu, s_die;

        if (idx > map->nr)
                return -1;

        cpu = map->map[idx];

        cpu = cpu_map__get_core_id(cpu);

        /* s_die is the combination of socket + die id */
        s_die = cpu_map__get_die(map, idx, data);
        if (s_die == -1)
                return -1;

        /*
         * encode socket in bit range 31:24
         * encode die id in bit range 23:16
         * core_id is relative to socket and die,
         * we need a global id. So we combine
         * socket + die id + core id
         */
        if (WARN_ONCE(cpu >> 16, "The core id number is too big.\n"))
                return -1;

        return (s_die << 16) | (cpu & 0xffff);
}

int cpu_map__build_socket_map(struct cpu_map *cpus, struct cpu_map **sockp)
{
        return cpu_map__build_map(cpus, sockp, cpu_map__get_socket, NULL);
}

int cpu_map__build_die_map(struct cpu_map *cpus, struct cpu_map **diep)
{
        return cpu_map__build_map(cpus, diep, cpu_map__get_die, NULL);
}

int cpu_map__build_core_map(struct cpu_map *cpus, struct cpu_map **corep)
{
        return cpu_map__build_map(cpus, corep, cpu_map__get_core, NULL);
}

/* setup simple routines to easily access node numbers given a cpu number */
static int get_max_num(char *path, int *max)
{
        size_t num;
        char *buf;
        int err = 0;

        if (filename__read_str(path, &buf, &num))
                return -1;

        buf[num] = '\0';

        /* start on the right, to find highest node num */
        while (--num) {
                if ((buf[num] == ',') || (buf[num] == '-')) {
                        num++;
                        break;
                }
        }
        if (sscanf(&buf[num], "%d", max) < 1) {
                err = -1;
                goto out;
        }

        /* convert from 0-based to 1-based */
        (*max)++;

out:
        free(buf);
        return err;
}

/* Determine highest possible cpu in the system for sparse allocation */
static void set_max_cpu_num(void)
{
        const char *mnt;
        char path[PATH_MAX];
        int ret = -1;

        /* set up default */
        max_cpu_num = 4096;
        max_present_cpu_num = 4096;

        mnt = sysfs__mountpoint();
        if (!mnt)
                goto out;

        /* get the highest possible cpu number for a sparse allocation */
        ret = snprintf(path, PATH_MAX, "%s/devices/system/cpu/possible", mnt);
        if (ret == PATH_MAX) {
                pr_err("sysfs path crossed PATH_MAX(%d) size\n", PATH_MAX);
                goto out;
        }

        ret = get_max_num(path, &max_cpu_num);
        if (ret)
                goto out;

        /* get the highest present cpu number for a sparse allocation */
        ret = snprintf(path, PATH_MAX, "%s/devices/system/cpu/present", mnt);
        if (ret == PATH_MAX) {
                pr_err("sysfs path crossed PATH_MAX(%d) size\n", PATH_MAX);
                goto out;
        }

        ret = get_max_num(path, &max_present_cpu_num);

out:
        if (ret)
                pr_err("Failed to read max cpus, using default of %d\n", max_cpu_num);
}

/* Determine highest possible node in the system for sparse allocation */
static void set_max_node_num(void)
{
        const char *mnt;
        char path[PATH_MAX];
        int ret = -1;

        /* set up default */
        max_node_num = 8;

        mnt = sysfs__mountpoint();
        if (!mnt)
                goto out;

        /* get the highest possible cpu number for a sparse allocation */
        ret = snprintf(path, PATH_MAX, "%s/devices/system/node/possible", mnt);
        if (ret == PATH_MAX) {
                pr_err("sysfs path crossed PATH_MAX(%d) size\n", PATH_MAX);
                goto out;
        }

        ret = get_max_num(path, &max_node_num);

out:
        if (ret)
                pr_err("Failed to read max nodes, using default of %d\n", max_node_num);
}

int cpu__max_node(void)
{
        if (unlikely(!max_node_num))
                set_max_node_num();

        return max_node_num;
}

int cpu__max_cpu(void)
{
        if (unlikely(!max_cpu_num))
                set_max_cpu_num();

        return max_cpu_num;
}

int cpu__max_present_cpu(void)
{
        if (unlikely(!max_present_cpu_num))
                set_max_cpu_num();

        return max_present_cpu_num;
}


int cpu__get_node(int cpu)
{
        if (unlikely(cpunode_map == NULL)) {
                pr_debug("cpu_map not initialized\n");
                return -1;
        }

        return cpunode_map[cpu];
}

static int init_cpunode_map(void)
{
        int i;

        set_max_cpu_num();
        set_max_node_num();

        cpunode_map = calloc(max_cpu_num, sizeof(int));
        if (!cpunode_map) {
                pr_err("%s: calloc failed\n", __func__);
                return -1;
        }

        for (i = 0; i < max_cpu_num; i++)
                cpunode_map[i] = -1;

        return 0;
}

int cpu__setup_cpunode_map(void)
{
        struct dirent *dent1, *dent2;
        DIR *dir1, *dir2;
        unsigned int cpu, mem;
        char buf[PATH_MAX];
        char path[PATH_MAX];
        const char *mnt;
        int n;

        /* initialize globals */
        if (init_cpunode_map())
                return -1;

        mnt = sysfs__mountpoint();
        if (!mnt)
                return 0;

        n = snprintf(path, PATH_MAX, "%s/devices/system/node", mnt);
        if (n == PATH_MAX) {
                pr_err("sysfs path crossed PATH_MAX(%d) size\n", PATH_MAX);
                return -1;
        }

        dir1 = opendir(path);
        if (!dir1)
                return 0;

        /* walk tree and setup map */
        while ((dent1 = readdir(dir1)) != NULL) {
                if (dent1->d_type != DT_DIR || sscanf(dent1->d_name, "node%u", &mem) < 1)
                        continue;

                n = snprintf(buf, PATH_MAX, "%s/%s", path, dent1->d_name);
                if (n == PATH_MAX) {
                        pr_err("sysfs path crossed PATH_MAX(%d) size\n", PATH_MAX);
                        continue;
                }

                dir2 = opendir(buf);
                if (!dir2)
                        continue;
                while ((dent2 = readdir(dir2)) != NULL) {
                        if (dent2->d_type != DT_LNK || sscanf(dent2->d_name, "cpu%u", &cpu) < 1)
                                continue;
                        cpunode_map[cpu] = mem;
                }
                closedir(dir2);
        }
        closedir(dir1);
        return 0;
}

bool cpu_map__has(struct cpu_map *cpus, int cpu)
{
        return cpu_map__idx(cpus, cpu) != -1;
}

int cpu_map__idx(struct cpu_map *cpus, int cpu)
{
        int i;

        for (i = 0; i < cpus->nr; ++i) {
                if (cpus->map[i] == cpu)
                        return i;
        }

        return -1;
}

int cpu_map__cpu(struct cpu_map *cpus, int idx)
{
        return cpus->map[idx];
}

size_t cpu_map__snprint(struct cpu_map *map, char *buf, size_t size)
{
        int i, cpu, start = -1;
        bool first = true;
        size_t ret = 0;

#define COMMA first ? "" : ","

        for (i = 0; i < map->nr + 1; i++) {
                bool last = i == map->nr;

                cpu = last ? INT_MAX : map->map[i];

                if (start == -1) {
                        start = i;
                        if (last) {
                                ret += snprintf(buf + ret, size - ret,
                                                "%s%d", COMMA,
                                                map->map[i]);
                        }
                } else if (((i - start) != (cpu - map->map[start])) || last) {
                        int end = i - 1;

                        if (start == end) {
                                ret += snprintf(buf + ret, size - ret,
                                                "%s%d", COMMA,
                                                map->map[start]);
                        } else {
                                ret += snprintf(buf + ret, size - ret,
                                                "%s%d-%d", COMMA,
                                                map->map[start], map->map[end]);
                        }
                        first = false;
                        start = i;
                }
        }

#undef COMMA

        pr_debug2("cpumask list: %s\n", buf);
        return ret;
}

static char hex_char(unsigned char val)
{
        if (val < 10)
                return val + '0';
        if (val < 16)
                return val - 10 + 'a';
        return '?';
}

size_t cpu_map__snprint_mask(struct cpu_map *map, char *buf, size_t size)
{
        int i, cpu;
        char *ptr = buf;
        unsigned char *bitmap;
        int last_cpu = cpu_map__cpu(map, map->nr - 1);

        if (buf == NULL)
                return 0;

        bitmap = zalloc(last_cpu / 8 + 1);
        if (bitmap == NULL) {
                buf[0] = '\0';
                return 0;
        }

        for (i = 0; i < map->nr; i++) {
                cpu = cpu_map__cpu(map, i);
                bitmap[cpu / 8] |= 1 << (cpu % 8);
        }

        for (cpu = last_cpu / 4 * 4; cpu >= 0; cpu -= 4) {
                unsigned char bits = bitmap[cpu / 8];

                if (cpu % 8)
                        bits >>= 4;
                else
                        bits &= 0xf;

                *ptr++ = hex_char(bits);
                if ((cpu % 32) == 0 && cpu > 0)
                        *ptr++ = ',';
        }
        *ptr = '\0';
        free(bitmap);

        buf[size - 1] = '\0';
        return ptr - buf;
}

const struct cpu_map *cpu_map__online(void) /* thread unsafe */
{
        static const struct cpu_map *online = NULL;

        if (!online)
                online = cpu_map__new(NULL); /* from /sys/devices/system/cpu/online */

        return online;
}