pmu.c

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#include <linux/list.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <stdio.h>
#include <dirent.h>
#include "sysfs.h"
#include "util.h"
#include "pmu.h"
#include "parse-events.h"
#include "cpumap.h"

#define EVENT_SOURCE_DEVICE_PATH "/bus/event_source/devices/"

int perf_pmu_parse(struct list_head *list, char *name);
extern FILE *perf_pmu_in;

static LIST_HEAD(pmus);

/*
 * Parse & process all the sysfs attributes located under
 * the directory specified in 'dir' parameter.
 */
static int pmu_format_parse(char *dir, struct list_head *head)
{
    struct dirent *evt_ent;
    DIR *format_dir;
    int ret = 0;

    format_dir = opendir(dir);
    if (!format_dir)
        return -EINVAL;

    while (!ret && (evt_ent = readdir(format_dir))) {
        char path[PATH_MAX];
        char *name = evt_ent->d_name;
        FILE *file;

        if (!strcmp(name, ".") || !strcmp(name, ".."))
            continue;

        snprintf(path, PATH_MAX, "%s/%s", dir, name);

        ret = -EINVAL;
        file = fopen(path, "r");
        if (!file)
            break;

        perf_pmu_in = file;
        ret = perf_pmu_parse(head, name);
        fclose(file);
    }

    closedir(format_dir);
    return ret;
}

/*
 * Reading/parsing the default pmu format definition, which should be
 * located at:
 * /sys/bus/event_source/devices/<dev>/format as sysfs group attributes.
 */
static int pmu_format(char *name, struct list_head *format)
{
    struct stat st;
    char path[PATH_MAX];
    const char *sysfs;

    sysfs = sysfs_find_mountpoint();
    if (!sysfs)
        return -1;

    snprintf(path, PATH_MAX,
         "%s" EVENT_SOURCE_DEVICE_PATH "%s/format", sysfs, name);

    if (stat(path, &st) < 0)
        return 0;   /* no error if format does not exist */

    if (pmu_format_parse(path, format))
        return -1;

    return 0;
}

static int perf_pmu__new_alias(struct list_head *list, char *name, FILE *file)
{
    struct perf_pmu__alias *alias;
    char buf[256];
    int ret;

    ret = fread(buf, 1, sizeof(buf), file);
    if (ret == 0)
        return -EINVAL;
    buf[ret] = 0;

    alias = malloc(sizeof(*alias));
    if (!alias)
        return -ENOMEM;

    INIT_LIST_HEAD(&alias->terms);
    ret = parse_events_terms(&alias->terms, buf);
    if (ret) {
        free(alias);
        return ret;
    }

    alias->name = strdup(name);
    list_add_tail(&alias->list, list);
    return 0;
}

/*
 * Process all the sysfs attributes located under the directory
 * specified in 'dir' parameter.
 */
static int pmu_aliases_parse(char *dir, struct list_head *head)
{
    struct dirent *evt_ent;
    DIR *event_dir;
    int ret = 0;

    event_dir = opendir(dir);
    if (!event_dir)
        return -EINVAL;

    while (!ret && (evt_ent = readdir(event_dir))) {
        char path[PATH_MAX];
        char *name = evt_ent->d_name;
        FILE *file;

        if (!strcmp(name, ".") || !strcmp(name, ".."))
            continue;

        snprintf(path, PATH_MAX, "%s/%s", dir, name);

        ret = -EINVAL;
        file = fopen(path, "r");
        if (!file)
            break;
        ret = perf_pmu__new_alias(head, name, file);
        fclose(file);
    }

    closedir(event_dir);
    return ret;
}

/*
 * Reading the pmu event aliases definition, which should be located at:
 * /sys/bus/event_source/devices/<dev>/events as sysfs group attributes.
 */
static int pmu_aliases(char *name, struct list_head *head)
{
    struct stat st;
    char path[PATH_MAX];
    const char *sysfs;

    sysfs = sysfs_find_mountpoint();
    if (!sysfs)
        return -1;

    snprintf(path, PATH_MAX,
         "%s/bus/event_source/devices/%s/events", sysfs, name);

    if (stat(path, &st) < 0)
        return -1;

    if (pmu_aliases_parse(path, head))
        return -1;

    return 0;
}

static int pmu_alias_terms(struct perf_pmu__alias *alias,
               struct list_head *terms)
{
    struct parse_events__term *term, *clone;
    LIST_HEAD(list);
    int ret;

    list_for_each_entry(term, &alias->terms, list) {
        ret = parse_events__term_clone(&clone, term);
        if (ret) {
            parse_events__free_terms(&list);
            return ret;
        }
        list_add_tail(&clone->list, &list);
    }
    list_splice(&list, terms);
    return 0;
}

/*
 * Reading/parsing the default pmu type value, which should be
 * located at:
 * /sys/bus/event_source/devices/<dev>/type as sysfs attribute.
 */
static int pmu_type(char *name, __u32 *type)
{
    struct stat st;
    char path[PATH_MAX];
    const char *sysfs;
    FILE *file;
    int ret = 0;

    sysfs = sysfs_find_mountpoint();
    if (!sysfs)
        return -1;

    snprintf(path, PATH_MAX,
         "%s" EVENT_SOURCE_DEVICE_PATH "%s/type", sysfs, name);

    if (stat(path, &st) < 0)
        return -1;

    file = fopen(path, "r");
    if (!file)
        return -EINVAL;

    if (1 != fscanf(file, "%u", type))
        ret = -1;

    fclose(file);
    return ret;
}

/* Add all pmus in sysfs to pmu list: */
static void pmu_read_sysfs(void)
{
    char path[PATH_MAX];
    const char *sysfs;
    DIR *dir;
    struct dirent *dent;

    sysfs = sysfs_find_mountpoint();
    if (!sysfs)
        return;

    snprintf(path, PATH_MAX,
         "%s" EVENT_SOURCE_DEVICE_PATH, sysfs);

    dir = opendir(path);
    if (!dir)
        return;

    while ((dent = readdir(dir))) {
        if (!strcmp(dent->d_name, ".") || !strcmp(dent->d_name, ".."))
            continue;
        /* add to static LIST_HEAD(pmus): */
        perf_pmu__find(dent->d_name);
    }

    closedir(dir);
}

static struct cpu_map *pmu_cpumask(char *name)
{
    struct stat st;
    char path[PATH_MAX];
    const char *sysfs;
    FILE *file;
    struct cpu_map *cpus;

    sysfs = sysfs_find_mountpoint();
    if (!sysfs)
        return NULL;

    snprintf(path, PATH_MAX,
         "%s/bus/event_source/devices/%s/cpumask", sysfs, name);

    if (stat(path, &st) < 0)
        return NULL;

    file = fopen(path, "r");
    if (!file)
        return NULL;

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

static struct perf_pmu *pmu_lookup(char *name)
{
    struct perf_pmu *pmu;
    LIST_HEAD(format);
    LIST_HEAD(aliases);
    __u32 type;

    /*
     * The pmu data we store & need consists of the pmu
     * type value and format definitions. Load both right
     * now.
     */
    if (pmu_format(name, &format))
        return NULL;

    if (pmu_type(name, &type))
        return NULL;

    pmu = zalloc(sizeof(*pmu));
    if (!pmu)
        return NULL;

    pmu->cpus = pmu_cpumask(name);

    pmu_aliases(name, &aliases);

    INIT_LIST_HEAD(&pmu->format);
    INIT_LIST_HEAD(&pmu->aliases);
    list_splice(&format, &pmu->format);
    list_splice(&aliases, &pmu->aliases);
    pmu->name = strdup(name);
    pmu->type = type;
    list_add_tail(&pmu->list, &pmus);
    return pmu;
}

static struct perf_pmu *pmu_find(char *name)
{
    struct perf_pmu *pmu;

    list_for_each_entry(pmu, &pmus, list)
        if (!strcmp(pmu->name, name))
            return pmu;

    return NULL;
}

struct perf_pmu *perf_pmu__scan(struct perf_pmu *pmu)
{
    /*
     * pmu iterator: If pmu is NULL, we start at the begin,
     * otherwise return the next pmu. Returns NULL on end.
     */
    if (!pmu) {
        pmu_read_sysfs();
        pmu = list_prepare_entry(pmu, &pmus, list);
    }
    list_for_each_entry_continue(pmu, &pmus, list)
        return pmu;
    return NULL;
}

struct perf_pmu *perf_pmu__find(char *name)
{
    struct perf_pmu *pmu;

    /*
     * Once PMU is loaded it stays in the list,
     * so we keep us from multiple reading/parsing
     * the pmu format definitions.
     */
    pmu = pmu_find(name);
    if (pmu)
        return pmu;

    return pmu_lookup(name);
}

static struct perf_pmu__format*
pmu_find_format(struct list_head *formats, char *name)
{
    struct perf_pmu__format *format;

    list_for_each_entry(format, formats, list)
        if (!strcmp(format->name, name))
            return format;

    return NULL;
}

/*
 * Returns value based on the format definition (format parameter)
 * and unformated value (value parameter).
 *
 * TODO maybe optimize a little ;)
 */
static __u64 pmu_format_value(unsigned long *format, __u64 value)
{
    unsigned long fbit, vbit;
    __u64 v = 0;

    for (fbit = 0, vbit = 0; fbit < PERF_PMU_FORMAT_BITS; fbit++) {

        if (!test_bit(fbit, format))
            continue;

        if (!(value & (1llu << vbit++)))
            continue;

        v |= (1llu << fbit);
    }

    return v;
}

/*
 * Setup one of config[12] attr members based on the
 * user input data - temr parameter.
 */
static int pmu_config_term(struct list_head *formats,
               struct perf_event_attr *attr,
               struct parse_events__term *term)
{
    struct perf_pmu__format *format;
    __u64 *vp;

    /*
     * Support only for hardcoded and numnerial terms.
     * Hardcoded terms should be already in, so nothing
     * to be done for them.
     */
    if (parse_events__is_hardcoded_term(term))
        return 0;

    if (term->type_val != PARSE_EVENTS__TERM_TYPE_NUM)
        return -EINVAL;

    format = pmu_find_format(formats, term->config);
    if (!format)
        return -EINVAL;

    switch (format->value) {
    case PERF_PMU_FORMAT_VALUE_CONFIG:
        vp = &attr->config;
        break;
    case PERF_PMU_FORMAT_VALUE_CONFIG1:
        vp = &attr->config1;
        break;
    case PERF_PMU_FORMAT_VALUE_CONFIG2:
        vp = &attr->config2;
        break;
    default:
        return -EINVAL;
    }

    /*
     * XXX If we ever decide to go with string values for
     * non-hardcoded terms, here's the place to translate
     * them into value.
     */
    *vp |= pmu_format_value(format->bits, term->val.num);
    return 0;
}

static int pmu_config(struct list_head *formats, struct perf_event_attr *attr,
              struct list_head *head_terms)
{
    struct parse_events__term *term;

    list_for_each_entry(term, head_terms, list)
        if (pmu_config_term(formats, attr, term))
            return -EINVAL;

    return 0;
}

/*
 * Configures event's 'attr' parameter based on the:
 * 1) users input - specified in terms parameter
 * 2) pmu format definitions - specified by pmu parameter
 */
int perf_pmu__config(struct perf_pmu *pmu, struct perf_event_attr *attr,
             struct list_head *head_terms)
{
    attr->type = pmu->type;
    return pmu_config(&pmu->format, attr, head_terms);
}

static struct perf_pmu__alias *pmu_find_alias(struct perf_pmu *pmu,
                          struct parse_events__term *term)
{
    struct perf_pmu__alias *alias;
    char *name;

    if (parse_events__is_hardcoded_term(term))
        return NULL;

    if (term->type_val == PARSE_EVENTS__TERM_TYPE_NUM) {
        if (term->val.num != 1)
            return NULL;
        if (pmu_find_format(&pmu->format, term->config))
            return NULL;
        name = term->config;
    } else if (term->type_val == PARSE_EVENTS__TERM_TYPE_STR) {
        if (strcasecmp(term->config, "event"))
            return NULL;
        name = term->val.str;
    } else {
        return NULL;
    }

    list_for_each_entry(alias, &pmu->aliases, list) {
        if (!strcasecmp(alias->name, name))
            return alias;
    }
    return NULL;
}

/*
 * Find alias in the terms list and replace it with the terms
 * defined for the alias
 */
int perf_pmu__check_alias(struct perf_pmu *pmu, struct list_head *head_terms)
{
    struct parse_events__term *term, *h;
    struct perf_pmu__alias *alias;
    int ret;

    list_for_each_entry_safe(term, h, head_terms, list) {
        alias = pmu_find_alias(pmu, term);
        if (!alias)
            continue;
        ret = pmu_alias_terms(alias, &term->list);
        if (ret)
            return ret;
        list_del(&term->list);
        free(term);
    }
    return 0;
}

int perf_pmu__new_format(struct list_head *list, char *name,
             int config, unsigned long *bits)
{
    struct perf_pmu__format *format;

    format = zalloc(sizeof(*format));
    if (!format)
        return -ENOMEM;

    format->name = strdup(name);
    format->value = config;
    memcpy(format->bits, bits, sizeof(format->bits));

    list_add_tail(&format->list, list);
    return 0;
}

void perf_pmu__set_format(unsigned long *bits, long from, long to)
{
    long b;

    if (!to)
        to = from;

    memset(bits, 0, BITS_TO_LONGS(PERF_PMU_FORMAT_BITS));
    for (b = from; b <= to; b++)
        set_bit(b, bits);
}

/* Simulated format definitions. */
static struct test_format {
    const char *name;
    const char *value;
} test_formats[] = {
    { "krava01", "config:0-1,62-63\n", },
    { "krava02", "config:10-17\n", },
    { "krava03", "config:5\n", },
    { "krava11", "config1:0,2,4,6,8,20-28\n", },
    { "krava12", "config1:63\n", },
    { "krava13", "config1:45-47\n", },
    { "krava21", "config2:0-3,10-13,20-23,30-33,40-43,50-53,60-63\n", },
    { "krava22", "config2:8,18,48,58\n", },
    { "krava23", "config2:28-29,38\n", },
};

#define TEST_FORMATS_CNT (sizeof(test_formats) / sizeof(struct test_format))

/* Simulated users input. */
static struct parse_events__term test_terms[] = {
    {
        .config    = (char *) "krava01",
        .val.num   = 15,
        .type_val  = PARSE_EVENTS__TERM_TYPE_NUM,
        .type_term = PARSE_EVENTS__TERM_TYPE_USER,
    },
    {
        .config    = (char *) "krava02",
        .val.num   = 170,
        .type_val  = PARSE_EVENTS__TERM_TYPE_NUM,
        .type_term = PARSE_EVENTS__TERM_TYPE_USER,
    },
    {
        .config    = (char *) "krava03",
        .val.num   = 1,
        .type_val  = PARSE_EVENTS__TERM_TYPE_NUM,
        .type_term = PARSE_EVENTS__TERM_TYPE_USER,
    },
    {
        .config    = (char *) "krava11",
        .val.num   = 27,
        .type_val  = PARSE_EVENTS__TERM_TYPE_NUM,
        .type_term = PARSE_EVENTS__TERM_TYPE_USER,
    },
    {
        .config    = (char *) "krava12",
        .val.num   = 1,
        .type_val  = PARSE_EVENTS__TERM_TYPE_NUM,
        .type_term = PARSE_EVENTS__TERM_TYPE_USER,
    },
    {
        .config    = (char *) "krava13",
        .val.num   = 2,
        .type_val  = PARSE_EVENTS__TERM_TYPE_NUM,
        .type_term = PARSE_EVENTS__TERM_TYPE_USER,
    },
    {
        .config    = (char *) "krava21",
        .val.num   = 119,
        .type_val  = PARSE_EVENTS__TERM_TYPE_NUM,
        .type_term = PARSE_EVENTS__TERM_TYPE_USER,
    },
    {
        .config    = (char *) "krava22",
        .val.num   = 11,
        .type_val  = PARSE_EVENTS__TERM_TYPE_NUM,
        .type_term = PARSE_EVENTS__TERM_TYPE_USER,
    },
    {
        .config    = (char *) "krava23",
        .val.num   = 2,
        .type_val  = PARSE_EVENTS__TERM_TYPE_NUM,
        .type_term = PARSE_EVENTS__TERM_TYPE_USER,
    },
};
#define TERMS_CNT (sizeof(test_terms) / sizeof(struct parse_events__term))

/*
 * Prepare format directory data, exported by kernel
 * at /sys/bus/event_source/devices/<dev>/format.
 */
static char *test_format_dir_get(void)
{
    static char dir[PATH_MAX];
    unsigned int i;

    snprintf(dir, PATH_MAX, "/tmp/perf-pmu-test-format-XXXXXX");
    if (!mkdtemp(dir))
        return NULL;

    for (i = 0; i < TEST_FORMATS_CNT; i++) {
        static char name[PATH_MAX];
        struct test_format *format = &test_formats[i];
        FILE *file;

        snprintf(name, PATH_MAX, "%s/%s", dir, format->name);

        file = fopen(name, "w");
        if (!file)
            return NULL;

        if (1 != fwrite(format->value, strlen(format->value), 1, file))
            break;

        fclose(file);
    }

    return dir;
}

/* Cleanup format directory. */
static int test_format_dir_put(char *dir)
{
    char buf[PATH_MAX];
    snprintf(buf, PATH_MAX, "rm -f %s/*\n", dir);
    if (system(buf))
        return -1;

    snprintf(buf, PATH_MAX, "rmdir %s\n", dir);
    return system(buf);
}

static struct list_head *test_terms_list(void)
{
    static LIST_HEAD(terms);
    unsigned int i;

    for (i = 0; i < TERMS_CNT; i++)
        list_add_tail(&test_terms[i].list, &terms);

    return &terms;
}

#undef TERMS_CNT

int perf_pmu__test(void)
{
    char *format = test_format_dir_get();
    LIST_HEAD(formats);
    struct list_head *terms = test_terms_list();
    int ret;

    if (!format)
        return -EINVAL;

    do {
        struct perf_event_attr attr;

        memset(&attr, 0, sizeof(attr));

        ret = pmu_format_parse(format, &formats);
        if (ret)
            break;

        ret = pmu_config(&formats, &attr, terms);
        if (ret)
            break;

        ret = -EINVAL;

        if (attr.config  != 0xc00000000002a823)
            break;
        if (attr.config1 != 0x8000400000000145)
            break;
        if (attr.config2 != 0x0400000020041d07)
            break;

        ret = 0;
    } while (0);

    test_format_dir_put(format);
    return ret;
}