cs-etm.c

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// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright(C) 2015 Linaro Limited. All rights reserved.
 * Author: Mathieu Poirier <mathieu.poirier@linaro.org>
 */

#include <api/fs/fs.h>
#include <linux/bitops.h>
#include <linux/compiler.h>
#include <linux/coresight-pmu.h>
#include <linux/kernel.h>
#include <linux/log2.h>
#include <linux/types.h>

#include "cs-etm.h"
#include "../../perf.h"
#include "../../util/auxtrace.h"
#include "../../util/cpumap.h"
#include "../../util/evlist.h"
#include "../../util/evsel.h"
#include "../../util/pmu.h"
#include "../../util/thread_map.h"
#include "../../util/cs-etm.h"

#include <stdlib.h>
#include <sys/stat.h>

#define ENABLE_SINK_MAX 128
#define CS_BUS_DEVICE_PATH "/bus/coresight/devices/"

struct cs_etm_recording {
    struct auxtrace_record  itr;
    struct perf_pmu     *cs_etm_pmu;
    struct perf_evlist  *evlist;
    bool            snapshot_mode;
    size_t          snapshot_size;
};

static bool cs_etm_is_etmv4(struct auxtrace_record *itr, int cpu);

static int cs_etm_parse_snapshot_options(struct auxtrace_record *itr,
                     struct record_opts *opts,
                     const char *str)
{
    struct cs_etm_recording *ptr =
                container_of(itr, struct cs_etm_recording, itr);
    unsigned long long snapshot_size = 0;
    char *endptr;

    if (str) {
        snapshot_size = strtoull(str, &endptr, 0);
        if (*endptr || snapshot_size > SIZE_MAX)
            return -1;
    }

    opts->auxtrace_snapshot_mode = true;
    opts->auxtrace_snapshot_size = snapshot_size;
    ptr->snapshot_size = snapshot_size;

    return 0;
}

static int cs_etm_recording_options(struct auxtrace_record *itr,
                    struct perf_evlist *evlist,
                    struct record_opts *opts)
{
    struct cs_etm_recording *ptr =
                container_of(itr, struct cs_etm_recording, itr);
    struct perf_pmu *cs_etm_pmu = ptr->cs_etm_pmu;
    struct perf_evsel *evsel, *cs_etm_evsel = NULL;
    const struct cpu_map *cpus = evlist->cpus;
    bool privileged = (geteuid() == 0 || perf_event_paranoid() < 0);

    ptr->evlist = evlist;
    ptr->snapshot_mode = opts->auxtrace_snapshot_mode;

    evlist__for_each_entry(evlist, evsel) {
        if (evsel->attr.type == cs_etm_pmu->type) {
            if (cs_etm_evsel) {
                pr_err("There may be only one %s event\n",
                       CORESIGHT_ETM_PMU_NAME);
                return -EINVAL;
            }
            evsel->attr.freq = 0;
            evsel->attr.sample_period = 1;
            cs_etm_evsel = evsel;
            opts->full_auxtrace = true;
        }
    }

    /* no need to continue if at least one event of interest was found */
    if (!cs_etm_evsel)
        return 0;

    if (opts->use_clockid) {
        pr_err("Cannot use clockid (-k option) with %s\n",
               CORESIGHT_ETM_PMU_NAME);
        return -EINVAL;
    }

    /* we are in snapshot mode */
    if (opts->auxtrace_snapshot_mode) {
        /*
         * No size were given to '-S' or '-m,', so go with
         * the default
         */
        if (!opts->auxtrace_snapshot_size &&
            !opts->auxtrace_mmap_pages) {
            if (privileged) {
                opts->auxtrace_mmap_pages = MiB(4) / page_size;
            } else {
                opts->auxtrace_mmap_pages =
                            KiB(128) / page_size;
                if (opts->mmap_pages == UINT_MAX)
                    opts->mmap_pages = KiB(256) / page_size;
            }
        } else if (!opts->auxtrace_mmap_pages && !privileged &&
                        opts->mmap_pages == UINT_MAX) {
            opts->mmap_pages = KiB(256) / page_size;
        }

        /*
         * '-m,xyz' was specified but no snapshot size, so make the
         * snapshot size as big as the auxtrace mmap area.
         */
        if (!opts->auxtrace_snapshot_size) {
            opts->auxtrace_snapshot_size =
                opts->auxtrace_mmap_pages * (size_t)page_size;
        }

        /*
         * -Sxyz was specified but no auxtrace mmap area, so make the
         * auxtrace mmap area big enough to fit the requested snapshot
         * size.
         */
        if (!opts->auxtrace_mmap_pages) {
            size_t sz = opts->auxtrace_snapshot_size;

            sz = round_up(sz, page_size) / page_size;
            opts->auxtrace_mmap_pages = roundup_pow_of_two(sz);
        }

        /* Snapshost size can't be bigger than the auxtrace area */
        if (opts->auxtrace_snapshot_size >
                opts->auxtrace_mmap_pages * (size_t)page_size) {
            pr_err("Snapshot size %zu must not be greater than AUX area tracing mmap size %zu\n",
                   opts->auxtrace_snapshot_size,
                   opts->auxtrace_mmap_pages * (size_t)page_size);
            return -EINVAL;
        }

        /* Something went wrong somewhere - this shouldn't happen */
        if (!opts->auxtrace_snapshot_size ||
            !opts->auxtrace_mmap_pages) {
            pr_err("Failed to calculate default snapshot size and/or AUX area tracing mmap pages\n");
            return -EINVAL;
        }
    }

    /* We are in full trace mode but '-m,xyz' wasn't specified */
    if (opts->full_auxtrace && !opts->auxtrace_mmap_pages) {
        if (privileged) {
            opts->auxtrace_mmap_pages = MiB(4) / page_size;
        } else {
            opts->auxtrace_mmap_pages = KiB(128) / page_size;
            if (opts->mmap_pages == UINT_MAX)
                opts->mmap_pages = KiB(256) / page_size;
        }

    }

    /* Validate auxtrace_mmap_pages provided by user */
    if (opts->auxtrace_mmap_pages) {
        unsigned int max_page = (KiB(128) / page_size);
        size_t sz = opts->auxtrace_mmap_pages * (size_t)page_size;

        if (!privileged &&
            opts->auxtrace_mmap_pages > max_page) {
            opts->auxtrace_mmap_pages = max_page;
            pr_err("auxtrace too big, truncating to %d\n",
                   max_page);
        }

        if (!is_power_of_2(sz)) {
            pr_err("Invalid mmap size for %s: must be a power of 2\n",
                   CORESIGHT_ETM_PMU_NAME);
            return -EINVAL;
        }
    }

    if (opts->auxtrace_snapshot_mode)
        pr_debug2("%s snapshot size: %zu\n", CORESIGHT_ETM_PMU_NAME,
              opts->auxtrace_snapshot_size);

    /*
     * To obtain the auxtrace buffer file descriptor, the auxtrace
     * event must come first.
     */
    perf_evlist__to_front(evlist, cs_etm_evsel);

    /*
     * In the case of per-cpu mmaps, we need the CPU on the
     * AUX event.
     */
    if (!cpu_map__empty(cpus))
        perf_evsel__set_sample_bit(cs_etm_evsel, CPU);

    /* Add dummy event to keep tracking */
    if (opts->full_auxtrace) {
        struct perf_evsel *tracking_evsel;
        int err;

        err = parse_events(evlist, "dummy:u", NULL);
        if (err)
            return err;

        tracking_evsel = perf_evlist__last(evlist);
        perf_evlist__set_tracking_event(evlist, tracking_evsel);

        tracking_evsel->attr.freq = 0;
        tracking_evsel->attr.sample_period = 1;

        /* In per-cpu case, always need the time of mmap events etc */
        if (!cpu_map__empty(cpus))
            perf_evsel__set_sample_bit(tracking_evsel, TIME);
    }

    return 0;
}

static u64 cs_etm_get_config(struct auxtrace_record *itr)
{
    u64 config = 0;
    struct cs_etm_recording *ptr =
            container_of(itr, struct cs_etm_recording, itr);
    struct perf_pmu *cs_etm_pmu = ptr->cs_etm_pmu;
    struct perf_evlist *evlist = ptr->evlist;
    struct perf_evsel *evsel;

    evlist__for_each_entry(evlist, evsel) {
        if (evsel->attr.type == cs_etm_pmu->type) {
            /*
             * Variable perf_event_attr::config is assigned to
             * ETMv3/PTM.  The bit fields have been made to match
             * the ETMv3.5 ETRMCR register specification.  See the
             * PMU_FORMAT_ATTR() declarations in
             * drivers/hwtracing/coresight/coresight-perf.c for
             * details.
             */
            config = evsel->attr.config;
            break;
        }
    }

    return config;
}

#ifndef BIT
#define BIT(N) (1UL << (N))
#endif

static u64 cs_etmv4_get_config(struct auxtrace_record *itr)
{
    u64 config = 0;
    u64 config_opts = 0;

    /*
     * The perf event variable config bits represent both
     * the command line options and register programming
     * bits in ETMv3/PTM. For ETMv4 we must remap options
     * to real bits
     */
    config_opts = cs_etm_get_config(itr);
    if (config_opts & BIT(ETM_OPT_CYCACC))
        config |= BIT(ETM4_CFG_BIT_CYCACC);
    if (config_opts & BIT(ETM_OPT_TS))
        config |= BIT(ETM4_CFG_BIT_TS);
    if (config_opts & BIT(ETM_OPT_RETSTK))
        config |= BIT(ETM4_CFG_BIT_RETSTK);

    return config;
}

static size_t
cs_etm_info_priv_size(struct auxtrace_record *itr __maybe_unused,
              struct perf_evlist *evlist __maybe_unused)
{
    int i;
    int etmv3 = 0, etmv4 = 0;
    struct cpu_map *event_cpus = evlist->cpus;
    struct cpu_map *online_cpus = cpu_map__new(NULL);

    /* cpu map is not empty, we have specific CPUs to work with */
    if (!cpu_map__empty(event_cpus)) {
        for (i = 0; i < cpu__max_cpu(); i++) {
            if (!cpu_map__has(event_cpus, i) ||
                !cpu_map__has(online_cpus, i))
                continue;

            if (cs_etm_is_etmv4(itr, i))
                etmv4++;
            else
                etmv3++;
        }
    } else {
        /* get configuration for all CPUs in the system */
        for (i = 0; i < cpu__max_cpu(); i++) {
            if (!cpu_map__has(online_cpus, i))
                continue;

            if (cs_etm_is_etmv4(itr, i))
                etmv4++;
            else
                etmv3++;
        }
    }

    cpu_map__put(online_cpus);

    return (CS_ETM_HEADER_SIZE +
           (etmv4 * CS_ETMV4_PRIV_SIZE) +
           (etmv3 * CS_ETMV3_PRIV_SIZE));
}

static const char *metadata_etmv3_ro[CS_ETM_PRIV_MAX] = {
    [CS_ETM_ETMCCER]    = "mgmt/etmccer",
    [CS_ETM_ETMIDR]     = "mgmt/etmidr",
};

static const char *metadata_etmv4_ro[CS_ETMV4_PRIV_MAX] = {
    [CS_ETMV4_TRCIDR0]      = "trcidr/trcidr0",
    [CS_ETMV4_TRCIDR1]      = "trcidr/trcidr1",
    [CS_ETMV4_TRCIDR2]      = "trcidr/trcidr2",
    [CS_ETMV4_TRCIDR8]      = "trcidr/trcidr8",
    [CS_ETMV4_TRCAUTHSTATUS]    = "mgmt/trcauthstatus",
};

static bool cs_etm_is_etmv4(struct auxtrace_record *itr, int cpu)
{
    bool ret = false;
    char path[PATH_MAX];
    int scan;
    unsigned int val;
    struct cs_etm_recording *ptr =
            container_of(itr, struct cs_etm_recording, itr);
    struct perf_pmu *cs_etm_pmu = ptr->cs_etm_pmu;

    /* Take any of the RO files for ETMv4 and see if it present */
    snprintf(path, PATH_MAX, "cpu%d/%s",
         cpu, metadata_etmv4_ro[CS_ETMV4_TRCIDR0]);
    scan = perf_pmu__scan_file(cs_etm_pmu, path, "%x", &val);

    /* The file was read successfully, we have a winner */
    if (scan == 1)
        ret = true;

    return ret;
}

static int cs_etm_get_ro(struct perf_pmu *pmu, int cpu, const char *path)
{
    char pmu_path[PATH_MAX];
    int scan;
    unsigned int val = 0;

    /* Get RO metadata from sysfs */
    snprintf(pmu_path, PATH_MAX, "cpu%d/%s", cpu, path);

    scan = perf_pmu__scan_file(pmu, pmu_path, "%x", &val);
    if (scan != 1)
        pr_err("%s: error reading: %s\n", __func__, pmu_path);

    return val;
}

static void cs_etm_get_metadata(int cpu, u32 *offset,
                struct auxtrace_record *itr,
                struct auxtrace_info_event *info)
{
    u32 increment;
    u64 magic;
    struct cs_etm_recording *ptr =
            container_of(itr, struct cs_etm_recording, itr);
    struct perf_pmu *cs_etm_pmu = ptr->cs_etm_pmu;

    /* first see what kind of tracer this cpu is affined to */
    if (cs_etm_is_etmv4(itr, cpu)) {
        magic = __perf_cs_etmv4_magic;
        /* Get trace configuration register */
        info->priv[*offset + CS_ETMV4_TRCCONFIGR] =
                        cs_etmv4_get_config(itr);
        /* Get traceID from the framework */
        info->priv[*offset + CS_ETMV4_TRCTRACEIDR] =
                        coresight_get_trace_id(cpu);
        /* Get read-only information from sysFS */
        info->priv[*offset + CS_ETMV4_TRCIDR0] =
            cs_etm_get_ro(cs_etm_pmu, cpu,
                      metadata_etmv4_ro[CS_ETMV4_TRCIDR0]);
        info->priv[*offset + CS_ETMV4_TRCIDR1] =
            cs_etm_get_ro(cs_etm_pmu, cpu,
                      metadata_etmv4_ro[CS_ETMV4_TRCIDR1]);
        info->priv[*offset + CS_ETMV4_TRCIDR2] =
            cs_etm_get_ro(cs_etm_pmu, cpu,
                      metadata_etmv4_ro[CS_ETMV4_TRCIDR2]);
        info->priv[*offset + CS_ETMV4_TRCIDR8] =
            cs_etm_get_ro(cs_etm_pmu, cpu,
                      metadata_etmv4_ro[CS_ETMV4_TRCIDR8]);
        info->priv[*offset + CS_ETMV4_TRCAUTHSTATUS] =
            cs_etm_get_ro(cs_etm_pmu, cpu,
                      metadata_etmv4_ro
                      [CS_ETMV4_TRCAUTHSTATUS]);

        /* How much space was used */
        increment = CS_ETMV4_PRIV_MAX;
    } else {
        magic = __perf_cs_etmv3_magic;
        /* Get configuration register */
        info->priv[*offset + CS_ETM_ETMCR] = cs_etm_get_config(itr);
        /* Get traceID from the framework */
        info->priv[*offset + CS_ETM_ETMTRACEIDR] =
                        coresight_get_trace_id(cpu);
        /* Get read-only information from sysFS */
        info->priv[*offset + CS_ETM_ETMCCER] =
            cs_etm_get_ro(cs_etm_pmu, cpu,
                      metadata_etmv3_ro[CS_ETM_ETMCCER]);
        info->priv[*offset + CS_ETM_ETMIDR] =
            cs_etm_get_ro(cs_etm_pmu, cpu,
                      metadata_etmv3_ro[CS_ETM_ETMIDR]);

        /* How much space was used */
        increment = CS_ETM_PRIV_MAX;
    }

    /* Build generic header portion */
    info->priv[*offset + CS_ETM_MAGIC] = magic;
    info->priv[*offset + CS_ETM_CPU] = cpu;
    /* Where the next CPU entry should start from */
    *offset += increment;
}

static int cs_etm_info_fill(struct auxtrace_record *itr,
                struct perf_session *session,
                struct auxtrace_info_event *info,
                size_t priv_size)
{
    int i;
    u32 offset;
    u64 nr_cpu, type;
    struct cpu_map *cpu_map;
    struct cpu_map *event_cpus = session->evlist->cpus;
    struct cpu_map *online_cpus = cpu_map__new(NULL);
    struct cs_etm_recording *ptr =
            container_of(itr, struct cs_etm_recording, itr);
    struct perf_pmu *cs_etm_pmu = ptr->cs_etm_pmu;

    if (priv_size != cs_etm_info_priv_size(itr, session->evlist))
        return -EINVAL;

    if (!session->evlist->nr_mmaps)
        return -EINVAL;

    /* If the cpu_map is empty all online CPUs are involved */
    if (cpu_map__empty(event_cpus)) {
        cpu_map = online_cpus;
    } else {
        /* Make sure all specified CPUs are online */
        for (i = 0; i < cpu_map__nr(event_cpus); i++) {
            if (cpu_map__has(event_cpus, i) &&
                !cpu_map__has(online_cpus, i))
                return -EINVAL;
        }

        cpu_map = event_cpus;
    }

    nr_cpu = cpu_map__nr(cpu_map);
    /* Get PMU type as dynamically assigned by the core */
    type = cs_etm_pmu->type;

    /* First fill out the session header */
    info->type = PERF_AUXTRACE_CS_ETM;
    info->priv[CS_HEADER_VERSION_0] = 0;
    info->priv[CS_PMU_TYPE_CPUS] = type << 32;
    info->priv[CS_PMU_TYPE_CPUS] |= nr_cpu;
    info->priv[CS_ETM_SNAPSHOT] = ptr->snapshot_mode;

    offset = CS_ETM_SNAPSHOT + 1;

    for (i = 0; i < cpu__max_cpu() && offset < priv_size; i++)
        if (cpu_map__has(cpu_map, i))
            cs_etm_get_metadata(i, &offset, itr, info);

    cpu_map__put(online_cpus);

    return 0;
}

static int cs_etm_find_snapshot(struct auxtrace_record *itr __maybe_unused,
                int idx, struct auxtrace_mmap *mm,
                unsigned char *data __maybe_unused,
                u64 *head, u64 *old)
{
    pr_debug3("%s: mmap index %d old head %zu new head %zu size %zu\n",
          __func__, idx, (size_t)*old, (size_t)*head, mm->len);

    *old = *head;
    *head += mm->len;

    return 0;
}

static int cs_etm_snapshot_start(struct auxtrace_record *itr)
{
    struct cs_etm_recording *ptr =
            container_of(itr, struct cs_etm_recording, itr);
    struct perf_evsel *evsel;

    evlist__for_each_entry(ptr->evlist, evsel) {
        if (evsel->attr.type == ptr->cs_etm_pmu->type)
            return perf_evsel__disable(evsel);
    }
    return -EINVAL;
}

static int cs_etm_snapshot_finish(struct auxtrace_record *itr)
{
    struct cs_etm_recording *ptr =
            container_of(itr, struct cs_etm_recording, itr);
    struct perf_evsel *evsel;

    evlist__for_each_entry(ptr->evlist, evsel) {
        if (evsel->attr.type == ptr->cs_etm_pmu->type)
            return perf_evsel__enable(evsel);
    }
    return -EINVAL;
}

static u64 cs_etm_reference(struct auxtrace_record *itr __maybe_unused)
{
    return (((u64) rand() <<  0) & 0x00000000FFFFFFFFull) |
        (((u64) rand() << 32) & 0xFFFFFFFF00000000ull);
}

static void cs_etm_recording_free(struct auxtrace_record *itr)
{
    struct cs_etm_recording *ptr =
            container_of(itr, struct cs_etm_recording, itr);
    free(ptr);
}

static int cs_etm_read_finish(struct auxtrace_record *itr, int idx)
{
    struct cs_etm_recording *ptr =
            container_of(itr, struct cs_etm_recording, itr);
    struct perf_evsel *evsel;

    evlist__for_each_entry(ptr->evlist, evsel) {
        if (evsel->attr.type == ptr->cs_etm_pmu->type)
            return perf_evlist__enable_event_idx(ptr->evlist,
                                 evsel, idx);
    }

    return -EINVAL;
}

struct auxtrace_record *cs_etm_record_init(int *err)
{
    struct perf_pmu *cs_etm_pmu;
    struct cs_etm_recording *ptr;

    cs_etm_pmu = perf_pmu__find(CORESIGHT_ETM_PMU_NAME);

    if (!cs_etm_pmu) {
        *err = -EINVAL;
        goto out;
    }

    ptr = zalloc(sizeof(struct cs_etm_recording));
    if (!ptr) {
        *err = -ENOMEM;
        goto out;
    }

    ptr->cs_etm_pmu         = cs_etm_pmu;
    ptr->itr.parse_snapshot_options = cs_etm_parse_snapshot_options;
    ptr->itr.recording_options  = cs_etm_recording_options;
    ptr->itr.info_priv_size     = cs_etm_info_priv_size;
    ptr->itr.info_fill      = cs_etm_info_fill;
    ptr->itr.find_snapshot      = cs_etm_find_snapshot;
    ptr->itr.snapshot_start     = cs_etm_snapshot_start;
    ptr->itr.snapshot_finish    = cs_etm_snapshot_finish;
    ptr->itr.reference      = cs_etm_reference;
    ptr->itr.free           = cs_etm_recording_free;
    ptr->itr.read_finish        = cs_etm_read_finish;

    *err = 0;
    return &ptr->itr;
out:
    return NULL;
}

static FILE *cs_device__open_file(const char *name)
{
    struct stat st;
    char path[PATH_MAX];
    const char *sysfs;

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

    snprintf(path, PATH_MAX,
         "%s" CS_BUS_DEVICE_PATH "%s", sysfs, name);

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

    return fopen(path, "w");

}

static int __printf(2, 3) cs_device__print_file(const char *name, const char *fmt, ...)
{
    va_list args;
    FILE *file;
    int ret = -EINVAL;

    va_start(args, fmt);
    file = cs_device__open_file(name);
    if (file) {
        ret = vfprintf(file, fmt, args);
        fclose(file);
    }
    va_end(args);
    return ret;
}

int cs_etm_set_drv_config(struct perf_evsel_config_term *term)
{
    int ret;
    char enable_sink[ENABLE_SINK_MAX];

    snprintf(enable_sink, ENABLE_SINK_MAX, "%s/%s",
         term->val.drv_cfg, "enable_sink");

    ret = cs_device__print_file(enable_sink, "%d", 1);
    if (ret < 0)
        return ret;

    return 0;
}