// SPDX-License-Identifier: GPL-2.0
#include <perf/evlist.h>
#include <perf/evsel.h>
#include <linux/bitops.h>
#include <linux/list.h>
#include <linux/hash.h>
#include <sys/ioctl.h>
#include <internal/evlist.h>
#include <internal/evsel.h>
#include <internal/xyarray.h>
#include <internal/mmap.h>
#include <internal/cpumap.h>
#include <internal/threadmap.h>
#include <internal/lib.h>
#include <linux/zalloc.h>
#include <stdlib.h>
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
#include <signal.h>
#include <poll.h>
#include <sys/mman.h>
#include <perf/cpumap.h>
#include <perf/threadmap.h>
#include <api/fd/array.h>

void perf_evlist__init(struct perf_evlist *evlist)
{
        INIT_LIST_HEAD(&evlist->entries);
        evlist->nr_entries = 0;
        fdarray__init(&evlist->pollfd, 64);
        perf_evlist__reset_id_hash(evlist);
}

static void __perf_evlist__propagate_maps(struct perf_evlist *evlist,
                                          struct perf_evsel *evsel)
{
        /*
         * We already have cpus for evsel (via PMU sysfs) so
         * keep it, if there's no target cpu list defined.
         */
        if (!evsel->own_cpus || evlist->has_user_cpus) {
                perf_cpu_map__put(evsel->cpus);
                evsel->cpus = perf_cpu_map__get(evlist->cpus);
        } else if (!evsel->system_wide && perf_cpu_map__empty(evlist->cpus)) {
                perf_cpu_map__put(evsel->cpus);
                evsel->cpus = perf_cpu_map__get(evlist->cpus);
        } else if (evsel->cpus != evsel->own_cpus) {
                perf_cpu_map__put(evsel->cpus);
                evsel->cpus = perf_cpu_map__get(evsel->own_cpus);
        }

        perf_thread_map__put(evsel->threads);
        evsel->threads = perf_thread_map__get(evlist->threads);
        evlist->all_cpus = perf_cpu_map__merge(evlist->all_cpus, evsel->cpus);
}

static void perf_evlist__propagate_maps(struct perf_evlist *evlist)
{
        struct perf_evsel *evsel;

        perf_evlist__for_each_evsel(evlist, evsel)
                __perf_evlist__propagate_maps(evlist, evsel);
}

void perf_evlist__add(struct perf_evlist *evlist,
                      struct perf_evsel *evsel)
{
        list_add_tail(&evsel->node, &evlist->entries);
        evlist->nr_entries += 1;
        __perf_evlist__propagate_maps(evlist, evsel);
}

void perf_evlist__remove(struct perf_evlist *evlist,
                         struct perf_evsel *evsel)
{
        list_del_init(&evsel->node);
        evlist->nr_entries -= 1;
}

struct perf_evlist *perf_evlist__new(void)
{
        struct perf_evlist *evlist = zalloc(sizeof(*evlist));

        if (evlist != NULL)
                perf_evlist__init(evlist);

        return evlist;
}

struct perf_evsel *
perf_evlist__next(struct perf_evlist *evlist, struct perf_evsel *prev)
{
        struct perf_evsel *next;

        if (!prev) {
                next = list_first_entry(&evlist->entries,
                                        struct perf_evsel,
                                        node);
        } else {
                next = list_next_entry(prev, node);
        }

        /* Empty list is noticed here so don't need checking on entry. */
        if (&next->node == &evlist->entries)
                return NULL;

        return next;
}

static void perf_evlist__purge(struct perf_evlist *evlist)
{
        struct perf_evsel *pos, *n;

        perf_evlist__for_each_entry_safe(evlist, n, pos) {
                list_del_init(&pos->node);
                perf_evsel__delete(pos);
        }

        evlist->nr_entries = 0;
}

void perf_evlist__exit(struct perf_evlist *evlist)
{
        perf_cpu_map__put(evlist->cpus);
        perf_cpu_map__put(evlist->all_cpus);
        perf_thread_map__put(evlist->threads);
        evlist->cpus = NULL;
        evlist->all_cpus = NULL;
        evlist->threads = NULL;
        fdarray__exit(&evlist->pollfd);
}

void perf_evlist__delete(struct perf_evlist *evlist)
{
        if (evlist == NULL)
                return;

        perf_evlist__munmap(evlist);
        perf_evlist__close(evlist);
        perf_evlist__purge(evlist);
        perf_evlist__exit(evlist);
        free(evlist);
}

void perf_evlist__set_maps(struct perf_evlist *evlist,
                           struct perf_cpu_map *cpus,
                           struct perf_thread_map *threads)
{
        /*
         * Allow for the possibility that one or another of the maps isn't being
         * changed i.e. don't put it.  Note we are assuming the maps that are
         * being applied are brand new and evlist is taking ownership of the
         * original reference count of 1.  If that is not the case it is up to
         * the caller to increase the reference count.
         */
        if (cpus != evlist->cpus) {
                perf_cpu_map__put(evlist->cpus);
                evlist->cpus = perf_cpu_map__get(cpus);
        }

        if (threads != evlist->threads) {
                perf_thread_map__put(evlist->threads);
                evlist->threads = perf_thread_map__get(threads);
        }

        if (!evlist->all_cpus && cpus)
                evlist->all_cpus = perf_cpu_map__get(cpus);

        perf_evlist__propagate_maps(evlist);
}

int perf_evlist__open(struct perf_evlist *evlist)
{
        struct perf_evsel *evsel;
        int err;

        perf_evlist__for_each_entry(evlist, evsel) {
                err = perf_evsel__open(evsel, evsel->cpus, evsel->threads);
                if (err < 0)
                        goto out_err;
        }

        return 0;

out_err:
        perf_evlist__close(evlist);
        return err;
}

void perf_evlist__close(struct perf_evlist *evlist)
{
        struct perf_evsel *evsel;

        perf_evlist__for_each_entry_reverse(evlist, evsel)
                perf_evsel__close(evsel);
}

void perf_evlist__enable(struct perf_evlist *evlist)
{
        struct perf_evsel *evsel;

        perf_evlist__for_each_entry(evlist, evsel)
                perf_evsel__enable(evsel);
}

void perf_evlist__disable(struct perf_evlist *evlist)
{
        struct perf_evsel *evsel;

        perf_evlist__for_each_entry(evlist, evsel)
                perf_evsel__disable(evsel);
}

u64 perf_evlist__read_format(struct perf_evlist *evlist)
{
        struct perf_evsel *first = perf_evlist__first(evlist);

        return first->attr.read_format;
}

#define SID(e, x, y) xyarray__entry(e->sample_id, x, y)

static void perf_evlist__id_hash(struct perf_evlist *evlist,
                                 struct perf_evsel *evsel,
                                 int cpu, int thread, u64 id)
{
        int hash;
        struct perf_sample_id *sid = SID(evsel, cpu, thread);

        sid->id = id;
        sid->evsel = evsel;
        hash = hash_64(sid->id, PERF_EVLIST__HLIST_BITS);
        hlist_add_head(&sid->node, &evlist->heads[hash]);
}

void perf_evlist__reset_id_hash(struct perf_evlist *evlist)
{
        int i;

        for (i = 0; i < PERF_EVLIST__HLIST_SIZE; ++i)
                INIT_HLIST_HEAD(&evlist->heads[i]);
}

void perf_evlist__id_add(struct perf_evlist *evlist,
                         struct perf_evsel *evsel,
                         int cpu, int thread, u64 id)
{
        perf_evlist__id_hash(evlist, evsel, cpu, thread, id);
        evsel->id[evsel->ids++] = id;
}

int perf_evlist__id_add_fd(struct perf_evlist *evlist,
                           struct perf_evsel *evsel,
                           int cpu, int thread, int fd)
{
        u64 read_data[4] = { 0, };
        int id_idx = 1; /* The first entry is the counter value */
        u64 id;
        int ret;

        ret = ioctl(fd, PERF_EVENT_IOC_ID, &id);
        if (!ret)
                goto add;

        if (errno != ENOTTY)
                return -1;

        /* Legacy way to get event id.. All hail to old kernels! */

        /*
         * This way does not work with group format read, so bail
         * out in that case.
         */
        if (perf_evlist__read_format(evlist) & PERF_FORMAT_GROUP)
                return -1;

        if (!(evsel->attr.read_format & PERF_FORMAT_ID) ||
            read(fd, &read_data, sizeof(read_data)) == -1)
                return -1;

        if (evsel->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
                ++id_idx;
        if (evsel->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
                ++id_idx;

        id = read_data[id_idx];

add:
        perf_evlist__id_add(evlist, evsel, cpu, thread, id);
        return 0;
}

int perf_evlist__alloc_pollfd(struct perf_evlist *evlist)
{
        int nr_cpus = perf_cpu_map__nr(evlist->cpus);
        int nr_threads = perf_thread_map__nr(evlist->threads);
        int nfds = 0;
        struct perf_evsel *evsel;

        perf_evlist__for_each_entry(evlist, evsel) {
                if (evsel->system_wide)
                        nfds += nr_cpus;
                else
                        nfds += nr_cpus * nr_threads;
        }

        if (fdarray__available_entries(&evlist->pollfd) < nfds &&
            fdarray__grow(&evlist->pollfd, nfds) < 0)
                return -ENOMEM;

        return 0;
}

int perf_evlist__add_pollfd(struct perf_evlist *evlist, int fd,
                            void *ptr, short revent, enum fdarray_flags flags)
{
        int pos = fdarray__add(&evlist->pollfd, fd, revent | POLLERR | POLLHUP, flags);

        if (pos >= 0) {
                evlist->pollfd.priv[pos].ptr = ptr;
                fcntl(fd, F_SETFL, O_NONBLOCK);
        }

        return pos;
}

static void perf_evlist__munmap_filtered(struct fdarray *fda, int fd,
                                         void *arg __maybe_unused)
{
        struct perf_mmap *map = fda->priv[fd].ptr;

        if (map)
                perf_mmap__put(map);
}

int perf_evlist__filter_pollfd(struct perf_evlist *evlist, short revents_and_mask)
{
        return fdarray__filter(&evlist->pollfd, revents_and_mask,
                               perf_evlist__munmap_filtered, NULL);
}

int perf_evlist__poll(struct perf_evlist *evlist, int timeout)
{
        return fdarray__poll(&evlist->pollfd, timeout);
}

static struct perf_mmap* perf_evlist__alloc_mmap(struct perf_evlist *evlist, bool overwrite)
{
        int i;
        struct perf_mmap *map;

        map = zalloc(evlist->nr_mmaps * sizeof(struct perf_mmap));
        if (!map)
                return NULL;

        for (i = 0; i < evlist->nr_mmaps; i++) {
                struct perf_mmap *prev = i ? &map[i - 1] : NULL;

                /*
                 * When the perf_mmap() call is made we grab one refcount, plus
                 * one extra to let perf_mmap__consume() get the last
                 * events after all real references (perf_mmap__get()) are
                 * dropped.
                 *
                 * Each PERF_EVENT_IOC_SET_OUTPUT points to this mmap and
                 * thus does perf_mmap__get() on it.
                 */
                perf_mmap__init(&map[i], prev, overwrite, NULL);
        }

        return map;
}

static void perf_evsel__set_sid_idx(struct perf_evsel *evsel, int idx, int cpu, int thread)
{
        struct perf_sample_id *sid = SID(evsel, cpu, thread);

        sid->idx = idx;
        sid->cpu = perf_cpu_map__cpu(evsel->cpus, cpu);
        sid->tid = perf_thread_map__pid(evsel->threads, thread);
}

static struct perf_mmap*
perf_evlist__mmap_cb_get(struct perf_evlist *evlist, bool overwrite, int idx)
{
        struct perf_mmap *maps;

        maps = overwrite ? evlist->mmap_ovw : evlist->mmap;

        if (!maps) {
                maps = perf_evlist__alloc_mmap(evlist, overwrite);
                if (!maps)
                        return NULL;

                if (overwrite)
                        evlist->mmap_ovw = maps;
                else
                        evlist->mmap = maps;
        }

        return &maps[idx];
}

#define FD(e, x, y) (*(int *) xyarray__entry(e->fd, x, y))

static int
perf_evlist__mmap_cb_mmap(struct perf_mmap *map, struct perf_mmap_param *mp,
                          int output, int cpu)
{
        return perf_mmap__mmap(map, mp, output, cpu);
}

static void perf_evlist__set_mmap_first(struct perf_evlist *evlist, struct perf_mmap *map,
                                        bool overwrite)
{
        if (overwrite)
                evlist->mmap_ovw_first = map;
        else
                evlist->mmap_first = map;
}

static int
mmap_per_evsel(struct perf_evlist *evlist, struct perf_evlist_mmap_ops *ops,
               int idx, struct perf_mmap_param *mp, int cpu_idx,
               int thread, int *_output, int *_output_overwrite)
{
        int evlist_cpu = perf_cpu_map__cpu(evlist->cpus, cpu_idx);
        struct perf_evsel *evsel;
        int revent;

        perf_evlist__for_each_entry(evlist, evsel) {
                bool overwrite = evsel->attr.write_backward;
                struct perf_mmap *map;
                int *output, fd, cpu;

                if (evsel->system_wide && thread)
                        continue;

                cpu = perf_cpu_map__idx(evsel->cpus, evlist_cpu);
                if (cpu == -1)
                        continue;

                map = ops->get(evlist, overwrite, idx);
                if (map == NULL)
                        return -ENOMEM;

                if (overwrite) {
                        mp->prot = PROT_READ;
                        output   = _output_overwrite;
                } else {
                        mp->prot = PROT_READ | PROT_WRITE;
                        output   = _output;
                }

                fd = FD(evsel, cpu, thread);

                if (*output == -1) {
                        *output = fd;

                        /*
                         * The last one will be done at perf_mmap__consume(), so that we
                         * make sure we don't prevent tools from consuming every last event in
                         * the ring buffer.
                         *
                         * I.e. we can get the POLLHUP meaning that the fd doesn't exist
                         * anymore, but the last events for it are still in the ring buffer,
                         * waiting to be consumed.
                         *
                         * Tools can chose to ignore this at their own discretion, but the
                         * evlist layer can't just drop it when filtering events in
                         * perf_evlist__filter_pollfd().
                         */
                        refcount_set(&map->refcnt, 2);

                        if (ops->mmap(map, mp, *output, evlist_cpu) < 0)
                                return -1;

                        if (!idx)
                                perf_evlist__set_mmap_first(evlist, map, overwrite);
                } else {
                        if (ioctl(fd, PERF_EVENT_IOC_SET_OUTPUT, *output) != 0)
                                return -1;

                        perf_mmap__get(map);
                }

                revent = !overwrite ? POLLIN : 0;

                if (!evsel->system_wide &&
                    perf_evlist__add_pollfd(evlist, fd, map, revent, fdarray_flag__default) < 0) {
                        perf_mmap__put(map);
                        return -1;
                }

                if (evsel->attr.read_format & PERF_FORMAT_ID) {
                        if (perf_evlist__id_add_fd(evlist, evsel, cpu, thread,
                                                   fd) < 0)
                                return -1;
                        perf_evsel__set_sid_idx(evsel, idx, cpu, thread);
                }
        }

        return 0;
}

static int
mmap_per_thread(struct perf_evlist *evlist, struct perf_evlist_mmap_ops *ops,
                struct perf_mmap_param *mp)
{
        int thread;
        int nr_threads = perf_thread_map__nr(evlist->threads);

        for (thread = 0; thread < nr_threads; thread++) {
                int output = -1;
                int output_overwrite = -1;

                if (ops->idx)
                        ops->idx(evlist, mp, thread, false);

                if (mmap_per_evsel(evlist, ops, thread, mp, 0, thread,
                                   &output, &output_overwrite))
                        goto out_unmap;
        }

        return 0;

out_unmap:
        perf_evlist__munmap(evlist);
        return -1;
}

static int
mmap_per_cpu(struct perf_evlist *evlist, struct perf_evlist_mmap_ops *ops,
             struct perf_mmap_param *mp)
{
        int nr_threads = perf_thread_map__nr(evlist->threads);
        int nr_cpus    = perf_cpu_map__nr(evlist->cpus);
        int cpu, thread;

        for (cpu = 0; cpu < nr_cpus; cpu++) {
                int output = -1;
                int output_overwrite = -1;

                if (ops->idx)
                        ops->idx(evlist, mp, cpu, true);

                for (thread = 0; thread < nr_threads; thread++) {
                        if (mmap_per_evsel(evlist, ops, cpu, mp, cpu,
                                           thread, &output, &output_overwrite))
                                goto out_unmap;
                }
        }

        return 0;

out_unmap:
        perf_evlist__munmap(evlist);
        return -1;
}

static int perf_evlist__nr_mmaps(struct perf_evlist *evlist)
{
        int nr_mmaps;

        nr_mmaps = perf_cpu_map__nr(evlist->cpus);
        if (perf_cpu_map__empty(evlist->cpus))
                nr_mmaps = perf_thread_map__nr(evlist->threads);

        return nr_mmaps;
}

int perf_evlist__mmap_ops(struct perf_evlist *evlist,
                          struct perf_evlist_mmap_ops *ops,
                          struct perf_mmap_param *mp)
{
        struct perf_evsel *evsel;
        const struct perf_cpu_map *cpus = evlist->cpus;
        const struct perf_thread_map *threads = evlist->threads;

        if (!ops || !ops->get || !ops->mmap)
                return -EINVAL;

        mp->mask = evlist->mmap_len - page_size - 1;

        evlist->nr_mmaps = perf_evlist__nr_mmaps(evlist);

        perf_evlist__for_each_entry(evlist, evsel) {
                if ((evsel->attr.read_format & PERF_FORMAT_ID) &&
                    evsel->sample_id == NULL &&
                    perf_evsel__alloc_id(evsel, perf_cpu_map__nr(cpus), threads->nr) < 0)
                        return -ENOMEM;
        }

        if (evlist->pollfd.entries == NULL && perf_evlist__alloc_pollfd(evlist) < 0)
                return -ENOMEM;

        if (perf_cpu_map__empty(cpus))
                return mmap_per_thread(evlist, ops, mp);

        return mmap_per_cpu(evlist, ops, mp);
}

int perf_evlist__mmap(struct perf_evlist *evlist, int pages)
{
        struct perf_mmap_param mp;
        struct perf_evlist_mmap_ops ops = {
                .get  = perf_evlist__mmap_cb_get,
                .mmap = perf_evlist__mmap_cb_mmap,
        };

        evlist->mmap_len = (pages + 1) * page_size;

        return perf_evlist__mmap_ops(evlist, &ops, &mp);
}

void perf_evlist__munmap(struct perf_evlist *evlist)
{
        int i;

        if (evlist->mmap) {
                for (i = 0; i < evlist->nr_mmaps; i++)
                        perf_mmap__munmap(&evlist->mmap[i]);
        }

        if (evlist->mmap_ovw) {
                for (i = 0; i < evlist->nr_mmaps; i++)
                        perf_mmap__munmap(&evlist->mmap_ovw[i]);
        }

        zfree(&evlist->mmap);
        zfree(&evlist->mmap_ovw);
}

struct perf_mmap*
perf_evlist__next_mmap(struct perf_evlist *evlist, struct perf_mmap *map,
                       bool overwrite)
{
        if (map)
                return map->next;

        return overwrite ? evlist->mmap_ovw_first : evlist->mmap_first;
}