// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright IBM Corp. 2018
 * Auxtrace support for s390 CPU-Measurement Sampling Facility
 *
 * Author(s):  Thomas Richter <tmricht@linux.ibm.com>
 *
 * Auxiliary traces are collected during 'perf record' using rbd000 event.
 * Several PERF_RECORD_XXX are generated during recording:
 *
 * PERF_RECORD_AUX:
 *      Records that new data landed in the AUX buffer part.
 * PERF_RECORD_AUXTRACE:
 *      Defines auxtrace data. Followed by the actual data. The contents of
 *      the auxtrace data is dependent on the event and the CPU.
 *      This record is generated by perf record command. For details
 *      see Documentation/perf.data-file-format.txt.
 * PERF_RECORD_AUXTRACE_INFO:
 *      Defines a table of contains for PERF_RECORD_AUXTRACE records. This
 *      record is generated during 'perf record' command. Each record contains
 *      up to 256 entries describing offset and size of the AUXTRACE data in the
 *      perf.data file.
 * PERF_RECORD_AUXTRACE_ERROR:
 *      Indicates an error during AUXTRACE collection such as buffer overflow.
 * PERF_RECORD_FINISHED_ROUND:
 *      Perf events are not necessarily in time stamp order, as they can be
 *      collected in parallel on different CPUs. If the events should be
 *      processed in time order they need to be sorted first.
 *      Perf report guarantees that there is no reordering over a
 *      PERF_RECORD_FINISHED_ROUND boundary event. All perf records with a
 *      time stamp lower than this record are processed (and displayed) before
 *      the succeeding perf record are processed.
 *
 * These records are evaluated during perf report command.
 *
 * 1. PERF_RECORD_AUXTRACE_INFO is used to set up the infrastructure for
 * auxiliary trace data processing. See s390_cpumsf_process_auxtrace_info()
 * below.
 * Auxiliary trace data is collected per CPU. To merge the data into the report
 * an auxtrace_queue is created for each CPU. It is assumed that the auxtrace
 * data is in ascending order.
 *
 * Each queue has a double linked list of auxtrace_buffers. This list contains
 * the offset and size of a CPU's auxtrace data. During auxtrace processing
 * the data portion is mmap()'ed.
 *
 * To sort the queues in chronological order, all queue access is controlled
 * by the auxtrace_heap. This is basically a stack, each stack element has two
 * entries, the queue number and a time stamp. However the stack is sorted by
 * the time stamps. The highest time stamp is at the bottom the lowest
 * (nearest) time stamp is at the top. That sort order is maintained at all
 * times!
 *
 * After the auxtrace infrastructure has been setup, the auxtrace queues are
 * filled with data (offset/size pairs) and the auxtrace_heap is populated.
 *
 * 2. PERF_RECORD_XXX processing triggers access to the auxtrace_queues.
 * Each record is handled by s390_cpumsf_process_event(). The time stamp of
 * the perf record is compared with the time stamp located on the auxtrace_heap
 * top element. If that time stamp is lower than the time stamp from the
 * record sample, the auxtrace queues will be processed. As auxtrace queues
 * control many auxtrace_buffers and each buffer can be quite large, the
 * auxtrace buffer might be processed only partially. In this case the
 * position in the auxtrace_buffer of that queue is remembered and the time
 * stamp of the last processed entry of the auxtrace_buffer replaces the
 * current auxtrace_heap top.
 *
 * 3. Auxtrace_queues might run of out data and are fed by the
 * PERF_RECORD_AUXTRACE handling, see s390_cpumsf_process_auxtrace_event().
 *
 * Event Generation
 * Each sampling-data entry in the auxiliary trace data generates a perf sample.
 * This sample is filled
 * with data from the auxtrace such as PID/TID, instruction address, CPU state,
 * etc. This sample is processed with perf_session__deliver_synth_event() to
 * be included into the GUI.
 *
 * 4. PERF_RECORD_FINISHED_ROUND event is used to process all the remaining
 * auxiliary traces entries until the time stamp of this record is reached
 * auxtrace_heap top. This is triggered by ordered_event->deliver().
 *
 *
 * Perf event processing.
 * Event processing of PERF_RECORD_XXX entries relies on time stamp entries.
 * This is the function call sequence:
 *
 * __cmd_report()
 * |
 * perf_session__process_events()
 * |
 * __perf_session__process_events()
 * |
 * perf_session__process_event()
 * |  This functions splits the PERF_RECORD_XXX records.
 * |  - Those generated by perf record command (type number equal or higher
 * |    than PERF_RECORD_USER_TYPE_START) are handled by
 * |    perf_session__process_user_event(see below)
 * |  - Those generated by the kernel are handled by
 * |    evlist__parse_sample_timestamp()
 * |
 * evlist__parse_sample_timestamp()
 * |  Extract time stamp from sample data.
 * |
 * perf_session__queue_event()
 * |  If timestamp is positive the sample is entered into an ordered_event
 * |  list, sort order is the timestamp. The event processing is deferred until
 * |  later (see perf_session__process_user_event()).
 * |  Other timestamps (0 or -1) are handled immediately by
 * |  perf_session__deliver_event(). These are events generated at start up
 * |  of command perf record. They create PERF_RECORD_COMM and PERF_RECORD_MMAP*
 * |  records. They are needed to create a list of running processes and its
 * |  memory mappings and layout. They are needed at the beginning to enable
 * |  command perf report to create process trees and memory mappings.
 * |
 * perf_session__deliver_event()
 * |  Delivers a PERF_RECORD_XXX entry for handling.
 * |
 * auxtrace__process_event()
 * |  The timestamp of the PERF_RECORD_XXX entry is taken to correlate with
 * |  time stamps from the auxiliary trace buffers. This enables
 * |  synchronization between auxiliary trace data and the events on the
 * |  perf.data file.
 * |
 * machine__deliver_event()
 * |  Handles the PERF_RECORD_XXX event. This depends on the record type.
 *    It might update the process tree, update a process memory map or enter
 *    a sample with IP and call back chain data into GUI data pool.
 *
 *
 * Deferred processing determined by perf_session__process_user_event() is
 * finally processed when a PERF_RECORD_FINISHED_ROUND is encountered. These
 * are generated during command perf record.
 * The timestamp of PERF_RECORD_FINISHED_ROUND event is taken to process all
 * PERF_RECORD_XXX entries stored in the ordered_event list. This list was
 * built up while reading the perf.data file.
 * Each event is now processed by calling perf_session__deliver_event().
 * This enables time synchronization between the data in the perf.data file and
 * the data in the auxiliary trace buffers.
 */

#include <endian.h>
#include <errno.h>
#include <byteswap.h>
#include <inttypes.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/bitops.h>
#include <linux/log2.h>
#include <linux/zalloc.h>

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

#include "color.h"
#include "evsel.h"
#include "evlist.h"
#include "machine.h"
#include "session.h"
#include "tool.h"
#include "debug.h"
#include "auxtrace.h"
#include "s390-cpumsf.h"
#include "s390-cpumsf-kernel.h"
#include "s390-cpumcf-kernel.h"
#include "config.h"

struct s390_cpumsf {
        struct auxtrace         auxtrace;
        struct auxtrace_queues  queues;
        struct auxtrace_heap    heap;
        struct perf_session     *session;
        struct machine          *machine;
        u32                     auxtrace_type;
        u32                     pmu_type;
        u16                     machine_type;
        bool                    data_queued;
        bool                    use_logfile;
        char                    *logdir;
};

struct s390_cpumsf_queue {
        struct s390_cpumsf      *sf;
        unsigned int            queue_nr;
        struct auxtrace_buffer  *buffer;
        int                     cpu;
        FILE                    *logfile;
        FILE                    *logfile_ctr;
};

/* Check if the raw data should be dumped to file. If this is the case and
 * the file to dump to has not been opened for writing, do so.
 *
 * Return 0 on success and greater zero on error so processing continues.
 */
static int s390_cpumcf_dumpctr(struct s390_cpumsf *sf,
                               struct perf_sample *sample)
{
        struct s390_cpumsf_queue *sfq;
        struct auxtrace_queue *q;
        int rc = 0;

        if (!sf->use_logfile || sf->queues.nr_queues <= sample->cpu)
                return rc;

        q = &sf->queues.queue_array[sample->cpu];
        sfq = q->priv;
        if (!sfq)               /* Queue not yet allocated */
                return rc;

        if (!sfq->logfile_ctr) {
                char *name;

                rc = (sf->logdir)
                        ? asprintf(&name, "%s/aux.ctr.%02x",
                                 sf->logdir, sample->cpu)
                        : asprintf(&name, "aux.ctr.%02x", sample->cpu);
                if (rc > 0)
                        sfq->logfile_ctr = fopen(name, "w");
                if (sfq->logfile_ctr == NULL) {
                        pr_err("Failed to open counter set log file %s, "
                               "continue...\n", name);
                        rc = 1;
                }
                free(name);
        }

        if (sfq->logfile_ctr) {
                /* See comment above for -4 */
                size_t n = fwrite(sample->raw_data, sample->raw_size - 4, 1,
                                  sfq->logfile_ctr);
                if (n != 1) {
                        pr_err("Failed to write counter set data\n");
                        rc = 1;
                }
        }
        return rc;
}

/* Display s390 CPU measurement facility basic-sampling data entry
 * Data written on s390 in big endian byte order and contains bit
 * fields across byte boundaries.
 */
static bool s390_cpumsf_basic_show(const char *color, size_t pos,
                                   struct hws_basic_entry *basicp)
{
        struct hws_basic_entry *basic = basicp;
#if __BYTE_ORDER == __LITTLE_ENDIAN
        struct hws_basic_entry local;
        unsigned long long word = be64toh(*(unsigned long long *)basicp);

        memset(&local, 0, sizeof(local));
        local.def = be16toh(basicp->def);
        local.prim_asn = word & 0xffff;
        local.CL = word >> 30 & 0x3;
        local.I = word >> 32 & 0x1;
        local.AS = word >> 33 & 0x3;
        local.P = word >> 35 & 0x1;
        local.W = word >> 36 & 0x1;
        local.T = word >> 37 & 0x1;
        local.U = word >> 40 & 0xf;
        local.ia = be64toh(basicp->ia);
        local.gpp = be64toh(basicp->gpp);
        local.hpp = be64toh(basicp->hpp);
        basic = &local;
#endif
        if (basic->def != 1) {
                pr_err("Invalid AUX trace basic entry [%#08zx]\n", pos);
                return false;
        }
        color_fprintf(stdout, color, "    [%#08zx] Basic   Def:%04x Inst:%#04x"
                      " %c%c%c%c AS:%d ASN:%#04x IA:%#018llx\n"
                      "\t\tCL:%d HPP:%#018llx GPP:%#018llx\n",
                      pos, basic->def, basic->U,
                      basic->T ? 'T' : ' ',
                      basic->W ? 'W' : ' ',
                      basic->P ? 'P' : ' ',
                      basic->I ? 'I' : ' ',
                      basic->AS, basic->prim_asn, basic->ia, basic->CL,
                      basic->hpp, basic->gpp);
        return true;
}

/* Display s390 CPU measurement facility diagnostic-sampling data entry.
 * Data written on s390 in big endian byte order and contains bit
 * fields across byte boundaries.
 */
static bool s390_cpumsf_diag_show(const char *color, size_t pos,
                                  struct hws_diag_entry *diagp)
{
        struct hws_diag_entry *diag = diagp;
#if __BYTE_ORDER == __LITTLE_ENDIAN
        struct hws_diag_entry local;
        unsigned long long word = be64toh(*(unsigned long long *)diagp);

        local.def = be16toh(diagp->def);
        local.I = word >> 32 & 0x1;
        diag = &local;
#endif
        if (diag->def < S390_CPUMSF_DIAG_DEF_FIRST) {
                pr_err("Invalid AUX trace diagnostic entry [%#08zx]\n", pos);
                return false;
        }
        color_fprintf(stdout, color, "    [%#08zx] Diag    Def:%04x %c\n",
                      pos, diag->def, diag->I ? 'I' : ' ');
        return true;
}

/* Return TOD timestamp contained in an trailer entry */
static unsigned long long trailer_timestamp(struct hws_trailer_entry *te,
                                            int idx)
{
        /* te->t set: TOD in STCKE format, bytes 8-15
         * to->t not set: TOD in STCK format, bytes 0-7
         */
        unsigned long long ts;

        memcpy(&ts, &te->timestamp[idx], sizeof(ts));
        return be64toh(ts);
}

/* Display s390 CPU measurement facility trailer entry */
static bool s390_cpumsf_trailer_show(const char *color, size_t pos,
                                     struct hws_trailer_entry *te)
{
#if __BYTE_ORDER == __LITTLE_ENDIAN
        struct hws_trailer_entry local;
        const unsigned long long flags = be64toh(te->flags);

        memset(&local, 0, sizeof(local));
        local.f = flags >> 63 & 0x1;
        local.a = flags >> 62 & 0x1;
        local.t = flags >> 61 & 0x1;
        local.bsdes = be16toh((flags >> 16 & 0xffff));
        local.dsdes = be16toh((flags & 0xffff));
        memcpy(&local.timestamp, te->timestamp, sizeof(te->timestamp));
        local.overflow = be64toh(te->overflow);
        local.clock_base = be64toh(te->progusage[0]) >> 63 & 1;
        local.progusage2 = be64toh(te->progusage2);
        te = &local;
#endif
        if (te->bsdes != sizeof(struct hws_basic_entry)) {
                pr_err("Invalid AUX trace trailer entry [%#08zx]\n", pos);
                return false;
        }
        color_fprintf(stdout, color, "    [%#08zx] Trailer %c%c%c bsdes:%d"
                      " dsdes:%d Overflow:%lld Time:%#llx\n"
                      "\t\tC:%d TOD:%#lx\n",
                      pos,
                      te->f ? 'F' : ' ',
                      te->a ? 'A' : ' ',
                      te->t ? 'T' : ' ',
                      te->bsdes, te->dsdes, te->overflow,
                      trailer_timestamp(te, te->clock_base),
                      te->clock_base, te->progusage2);
        return true;
}

/* Test a sample data block. It must be 4KB or a multiple thereof in size and
 * 4KB page aligned. Each sample data page has a trailer entry at the
 * end which contains the sample entry data sizes.
 *
 * Return true if the sample data block passes the checks and set the
 * basic set entry size and diagnostic set entry size.
 *
 * Return false on failure.
 *
 * Note: Old hardware does not set the basic or diagnostic entry sizes
 * in the trailer entry. Use the type number instead.
 */
static bool s390_cpumsf_validate(int machine_type,
                                 unsigned char *buf, size_t len,
                                 unsigned short *bsdes,
                                 unsigned short *dsdes)
{
        struct hws_basic_entry *basic = (struct hws_basic_entry *)buf;
        struct hws_trailer_entry *te;

        *dsdes = *bsdes = 0;
        if (len & (S390_CPUMSF_PAGESZ - 1))     /* Illegal size */
                return false;
        if (be16toh(basic->def) != 1)   /* No basic set entry, must be first */
                return false;
        /* Check for trailer entry at end of SDB */
        te = (struct hws_trailer_entry *)(buf + S390_CPUMSF_PAGESZ
                                              - sizeof(*te));
        *bsdes = be16toh(te->bsdes);
        *dsdes = be16toh(te->dsdes);
        if (!te->bsdes && !te->dsdes) {
                /* Very old hardware, use CPUID */
                switch (machine_type) {
                case 2097:
                case 2098:
                        *dsdes = 64;
                        *bsdes = 32;
                        break;
                case 2817:
                case 2818:
                        *dsdes = 74;
                        *bsdes = 32;
                        break;
                case 2827:
                case 2828:
                        *dsdes = 85;
                        *bsdes = 32;
                        break;
                case 2964:
                case 2965:
                        *dsdes = 112;
                        *bsdes = 32;
                        break;
                default:
                        /* Illegal trailer entry */
                        return false;
                }
        }
        return true;
}

/* Return true if there is room for another entry */
static bool s390_cpumsf_reached_trailer(size_t entry_sz, size_t pos)
{
        size_t payload = S390_CPUMSF_PAGESZ - sizeof(struct hws_trailer_entry);

        if (payload - (pos & (S390_CPUMSF_PAGESZ - 1)) < entry_sz)
                return false;
        return true;
}

/* Dump an auxiliary buffer. These buffers are multiple of
 * 4KB SDB pages.
 */
static void s390_cpumsf_dump(struct s390_cpumsf *sf,
                             unsigned char *buf, size_t len)
{
        const char *color = PERF_COLOR_BLUE;
        struct hws_basic_entry *basic;
        struct hws_diag_entry *diag;
        unsigned short bsdes, dsdes;
        size_t pos = 0;

        color_fprintf(stdout, color,
                      ". ... s390 AUX data: size %zu bytes\n",
                      len);

        if (!s390_cpumsf_validate(sf->machine_type, buf, len, &bsdes,
                                  &dsdes)) {
                pr_err("Invalid AUX trace data block size:%zu"
                       " (type:%d bsdes:%hd dsdes:%hd)\n",
                       len, sf->machine_type, bsdes, dsdes);
                return;
        }

        /* s390 kernel always returns 4KB blocks fully occupied,
         * no partially filled SDBs.
         */
        while (pos < len) {
                /* Handle Basic entry */
                basic = (struct hws_basic_entry *)(buf + pos);
                if (s390_cpumsf_basic_show(color, pos, basic))
                        pos += bsdes;
                else
                        return;

                /* Handle Diagnostic entry */
                diag = (struct hws_diag_entry *)(buf + pos);
                if (s390_cpumsf_diag_show(color, pos, diag))
                        pos += dsdes;
                else
                        return;

                /* Check for trailer entry */
                if (!s390_cpumsf_reached_trailer(bsdes + dsdes, pos)) {
                        /* Show trailer entry */
                        struct hws_trailer_entry te;

                        pos = (pos + S390_CPUMSF_PAGESZ)
                               & ~(S390_CPUMSF_PAGESZ - 1);
                        pos -= sizeof(te);
                        memcpy(&te, buf + pos, sizeof(te));
                        /* Set descriptor sizes in case of old hardware
                         * where these values are not set.
                         */
                        te.bsdes = bsdes;
                        te.dsdes = dsdes;
                        if (s390_cpumsf_trailer_show(color, pos, &te))
                                pos += sizeof(te);
                        else
                                return;
                }
        }
}

static void s390_cpumsf_dump_event(struct s390_cpumsf *sf, unsigned char *buf,
                                   size_t len)
{
        printf(".\n");
        s390_cpumsf_dump(sf, buf, len);
}

#define S390_LPP_PID_MASK       0xffffffff

static bool s390_cpumsf_make_event(size_t pos,
                                   struct hws_basic_entry *basic,
                                   struct s390_cpumsf_queue *sfq)
{
        struct perf_sample sample = {
                                .ip = basic->ia,
                                .pid = basic->hpp & S390_LPP_PID_MASK,
                                .tid = basic->hpp & S390_LPP_PID_MASK,
                                .cpumode = PERF_RECORD_MISC_CPUMODE_UNKNOWN,
                                .cpu = sfq->cpu,
                                .period = 1
                            };
        union perf_event event;

        memset(&event, 0, sizeof(event));
        if (basic->CL == 1)     /* Native LPAR mode */
                sample.cpumode = basic->P ? PERF_RECORD_MISC_USER
                                          : PERF_RECORD_MISC_KERNEL;
        else if (basic->CL == 2)        /* Guest kernel/user space */
                sample.cpumode = basic->P ? PERF_RECORD_MISC_GUEST_USER
                                          : PERF_RECORD_MISC_GUEST_KERNEL;
        else if (basic->gpp || basic->prim_asn != 0xffff)
                /* Use heuristics on old hardware */
                sample.cpumode = basic->P ? PERF_RECORD_MISC_GUEST_USER
                                          : PERF_RECORD_MISC_GUEST_KERNEL;
        else
                sample.cpumode = basic->P ? PERF_RECORD_MISC_USER
                                          : PERF_RECORD_MISC_KERNEL;

        event.sample.header.type = PERF_RECORD_SAMPLE;
        event.sample.header.misc = sample.cpumode;
        event.sample.header.size = sizeof(struct perf_event_header);

        pr_debug4("%s pos:%#zx ip:%#" PRIx64 " P:%d CL:%d pid:%d.%d cpumode:%d cpu:%d\n",
                 __func__, pos, sample.ip, basic->P, basic->CL, sample.pid,
                 sample.tid, sample.cpumode, sample.cpu);
        if (perf_session__deliver_synth_event(sfq->sf->session, &event,
                                              &sample)) {
                pr_err("s390 Auxiliary Trace: failed to deliver event\n");
                return false;
        }
        return true;
}

static unsigned long long get_trailer_time(const unsigned char *buf)
{
        struct hws_trailer_entry *te;
        unsigned long long aux_time, progusage2;
        bool clock_base;

        te = (struct hws_trailer_entry *)(buf + S390_CPUMSF_PAGESZ
                                              - sizeof(*te));

#if __BYTE_ORDER == __LITTLE_ENDIAN
        clock_base = be64toh(te->progusage[0]) >> 63 & 0x1;
        progusage2 = be64toh(te->progusage[1]);
#else
        clock_base = te->clock_base;
        progusage2 = te->progusage2;
#endif
        if (!clock_base)        /* TOD_CLOCK_BASE value missing */
                return 0;

        /* Correct calculation to convert time stamp in trailer entry to
         * nano seconds (taken from arch/s390 function tod_to_ns()).
         * TOD_CLOCK_BASE is stored in trailer entry member progusage2.
         */
        aux_time = trailer_timestamp(te, clock_base) - progusage2;
        aux_time = (aux_time >> 9) * 125 + (((aux_time & 0x1ff) * 125) >> 9);
        return aux_time;
}

/* Process the data samples of a single queue. The first parameter is a
 * pointer to the queue, the second parameter is the time stamp. This
 * is the time stamp:
 * - of the event that triggered this processing.
 * - or the time stamp when the last processing of this queue stopped.
 *   In this case it stopped at a 4KB page boundary and record the
 *   position on where to continue processing on the next invocation
 *   (see buffer->use_data and buffer->use_size).
 *
 * When this function returns the second parameter is updated to
 * reflect the time stamp of the last processed auxiliary data entry
 * (taken from the trailer entry of that page). The caller uses this
 * returned time stamp to record the last processed entry in this
 * queue.
 *
 * The function returns:
 * 0:  Processing successful. The second parameter returns the
 *     time stamp from the trailer entry until which position
 *     processing took place. Subsequent calls resume from this
 *     position.
 * <0: An error occurred during processing. The second parameter
 *     returns the maximum time stamp.
 * >0: Done on this queue. The second parameter returns the
 *     maximum time stamp.
 */
static int s390_cpumsf_samples(struct s390_cpumsf_queue *sfq, u64 *ts)
{
        struct s390_cpumsf *sf = sfq->sf;
        unsigned char *buf = sfq->buffer->use_data;
        size_t len = sfq->buffer->use_size;
        struct hws_basic_entry *basic;
        unsigned short bsdes, dsdes;
        size_t pos = 0;
        int err = 1;
        u64 aux_ts;

        if (!s390_cpumsf_validate(sf->machine_type, buf, len, &bsdes,
                                  &dsdes)) {
                *ts = ~0ULL;
                return -1;
        }

        /* Get trailer entry time stamp and check if entries in
         * this auxiliary page are ready for processing. If the
         * time stamp of the first entry is too high, whole buffer
         * can be skipped. In this case return time stamp.
         */
        aux_ts = get_trailer_time(buf);
        if (!aux_ts) {
                pr_err("[%#08" PRIx64 "] Invalid AUX trailer entry TOD clock base\n",
                       (s64)sfq->buffer->data_offset);
                aux_ts = ~0ULL;
                goto out;
        }
        if (aux_ts > *ts) {
                *ts = aux_ts;
                return 0;
        }

        while (pos < len) {
                /* Handle Basic entry */
                basic = (struct hws_basic_entry *)(buf + pos);
                if (s390_cpumsf_make_event(pos, basic, sfq))
                        pos += bsdes;
                else {
                        err = -EBADF;
                        goto out;
                }

                pos += dsdes;   /* Skip diagnostic entry */

                /* Check for trailer entry */
                if (!s390_cpumsf_reached_trailer(bsdes + dsdes, pos)) {
                        pos = (pos + S390_CPUMSF_PAGESZ)
                               & ~(S390_CPUMSF_PAGESZ - 1);
                        /* Check existence of next page */
                        if (pos >= len)
                                break;
                        aux_ts = get_trailer_time(buf + pos);
                        if (!aux_ts) {
                                aux_ts = ~0ULL;
                                goto out;
                        }
                        if (aux_ts > *ts) {
                                *ts = aux_ts;
                                sfq->buffer->use_data += pos;
                                sfq->buffer->use_size -= pos;
                                return 0;
                        }
                }
        }
out:
        *ts = aux_ts;
        sfq->buffer->use_size = 0;
        sfq->buffer->use_data = NULL;
        return err;     /* Buffer completely scanned or error */
}

/* Run the s390 auxiliary trace decoder.
 * Select the queue buffer to operate on, the caller already selected
 * the proper queue, depending on second parameter 'ts'.
 * This is the time stamp until which the auxiliary entries should
 * be processed. This value is updated by called functions and
 * returned to the caller.
 *
 * Resume processing in the current buffer. If there is no buffer
 * get a new buffer from the queue and setup start position for
 * processing.
 * When a buffer is completely processed remove it from the queue
 * before returning.
 *
 * This function returns
 * 1: When the queue is empty. Second parameter will be set to
 *    maximum time stamp.
 * 0: Normal processing done.
 * <0: Error during queue buffer setup. This causes the caller
 *     to stop processing completely.
 */
static int s390_cpumsf_run_decoder(struct s390_cpumsf_queue *sfq,
                                   u64 *ts)
{

        struct auxtrace_buffer *buffer;
        struct auxtrace_queue *queue;
        int err;

        queue = &sfq->sf->queues.queue_array[sfq->queue_nr];

        /* Get buffer and last position in buffer to resume
         * decoding the auxiliary entries. One buffer might be large
         * and decoding might stop in between. This depends on the time
         * stamp of the trailer entry in each page of the auxiliary
         * data and the time stamp of the event triggering the decoding.
         */
        if (sfq->buffer == NULL) {
                sfq->buffer = buffer = auxtrace_buffer__next(queue,
                                                             sfq->buffer);
                if (!buffer) {
                        *ts = ~0ULL;
                        return 1;       /* Processing done on this queue */
                }
                /* Start with a new buffer on this queue */
                if (buffer->data) {
                        buffer->use_size = buffer->size;
                        buffer->use_data = buffer->data;
                }
                if (sfq->logfile) {     /* Write into log file */
                        size_t rc = fwrite(buffer->data, buffer->size, 1,
                                           sfq->logfile);
                        if (rc != 1)
                                pr_err("Failed to write auxiliary data\n");
                }
        } else
                buffer = sfq->buffer;

        if (!buffer->data) {
                int fd = perf_data__fd(sfq->sf->session->data);

                buffer->data = auxtrace_buffer__get_data(buffer, fd);
                if (!buffer->data)
                        return -ENOMEM;
                buffer->use_size = buffer->size;
                buffer->use_data = buffer->data;

                if (sfq->logfile) {     /* Write into log file */
                        size_t rc = fwrite(buffer->data, buffer->size, 1,
                                           sfq->logfile);
                        if (rc != 1)
                                pr_err("Failed to write auxiliary data\n");
                }
        }
        pr_debug4("%s queue_nr:%d buffer:%" PRId64 " offset:%#" PRIx64 " size:%#zx rest:%#zx\n",
                  __func__, sfq->queue_nr, buffer->buffer_nr, buffer->offset,
                  buffer->size, buffer->use_size);
        err = s390_cpumsf_samples(sfq, ts);

        /* If non-zero, there is either an error (err < 0) or the buffer is
         * completely done (err > 0). The error is unrecoverable, usually
         * some descriptors could not be read successfully, so continue with
         * the next buffer.
         * In both cases the parameter 'ts' has been updated.
         */
        if (err) {
                sfq->buffer = NULL;
                list_del_init(&buffer->list);
                auxtrace_buffer__free(buffer);
                if (err > 0)            /* Buffer done, no error */
                        err = 0;
        }
        return err;
}

static struct s390_cpumsf_queue *
s390_cpumsf_alloc_queue(struct s390_cpumsf *sf, unsigned int queue_nr)
{
        struct s390_cpumsf_queue *sfq;

        sfq = zalloc(sizeof(struct s390_cpumsf_queue));
        if (sfq == NULL)
                return NULL;

        sfq->sf = sf;
        sfq->queue_nr = queue_nr;
        sfq->cpu = -1;
        if (sf->use_logfile) {
                char *name;
                int rc;

                rc = (sf->logdir)
                        ? asprintf(&name, "%s/aux.smp.%02x",
                                 sf->logdir, queue_nr)
                        : asprintf(&name, "aux.smp.%02x", queue_nr);
                if (rc > 0)
                        sfq->logfile = fopen(name, "w");
                if (sfq->logfile == NULL) {
                        pr_err("Failed to open auxiliary log file %s,"
                               "continue...\n", name);
                        sf->use_logfile = false;
                }
                free(name);
        }
        return sfq;
}

static int s390_cpumsf_setup_queue(struct s390_cpumsf *sf,
                                   struct auxtrace_queue *queue,
                                   unsigned int queue_nr, u64 ts)
{
        struct s390_cpumsf_queue *sfq = queue->priv;

        if (list_empty(&queue->head))
                return 0;

        if (sfq == NULL) {
                sfq = s390_cpumsf_alloc_queue(sf, queue_nr);
                if (!sfq)
                        return -ENOMEM;
                queue->priv = sfq;

                if (queue->cpu != -1)
                        sfq->cpu = queue->cpu;
        }
        return auxtrace_heap__add(&sf->heap, queue_nr, ts);
}

static int s390_cpumsf_setup_queues(struct s390_cpumsf *sf, u64 ts)
{
        unsigned int i;
        int ret = 0;

        for (i = 0; i < sf->queues.nr_queues; i++) {
                ret = s390_cpumsf_setup_queue(sf, &sf->queues.queue_array[i],
                                              i, ts);
                if (ret)
                        break;
        }
        return ret;
}

static int s390_cpumsf_update_queues(struct s390_cpumsf *sf, u64 ts)
{
        if (!sf->queues.new_data)
                return 0;

        sf->queues.new_data = false;
        return s390_cpumsf_setup_queues(sf, ts);
}

static int s390_cpumsf_process_queues(struct s390_cpumsf *sf, u64 timestamp)
{
        unsigned int queue_nr;
        u64 ts;
        int ret;

        while (1) {
                struct auxtrace_queue *queue;
                struct s390_cpumsf_queue *sfq;

                if (!sf->heap.heap_cnt)
                        return 0;

                if (sf->heap.heap_array[0].ordinal >= timestamp)
                        return 0;

                queue_nr = sf->heap.heap_array[0].queue_nr;
                queue = &sf->queues.queue_array[queue_nr];
                sfq = queue->priv;

                auxtrace_heap__pop(&sf->heap);
                if (sf->heap.heap_cnt) {
                        ts = sf->heap.heap_array[0].ordinal + 1;
                        if (ts > timestamp)
                                ts = timestamp;
                } else {
                        ts = timestamp;
                }

                ret = s390_cpumsf_run_decoder(sfq, &ts);
                if (ret < 0) {
                        auxtrace_heap__add(&sf->heap, queue_nr, ts);
                        return ret;
                }
                if (!ret) {
                        ret = auxtrace_heap__add(&sf->heap, queue_nr, ts);
                        if (ret < 0)
                                return ret;
                }
        }
        return 0;
}

static int s390_cpumsf_synth_error(struct s390_cpumsf *sf, int code, int cpu,
                                   pid_t pid, pid_t tid, u64 ip, u64 timestamp)
{
        char msg[MAX_AUXTRACE_ERROR_MSG];
        union perf_event event;
        int err;

        strncpy(msg, "Lost Auxiliary Trace Buffer", sizeof(msg) - 1);
        auxtrace_synth_error(&event.auxtrace_error, PERF_AUXTRACE_ERROR_ITRACE,
                             code, cpu, pid, tid, ip, msg, timestamp);

        err = perf_session__deliver_synth_event(sf->session, &event, NULL);
        if (err)
                pr_err("s390 Auxiliary Trace: failed to deliver error event,"
                        "error %d\n", err);
        return err;
}

static int s390_cpumsf_lost(struct s390_cpumsf *sf, struct perf_sample *sample)
{
        return s390_cpumsf_synth_error(sf, 1, sample->cpu,
                                       sample->pid, sample->tid, 0,
                                       sample->time);
}

static int
s390_cpumsf_process_event(struct perf_session *session,
                          union perf_event *event,
                          struct perf_sample *sample,
                          struct perf_tool *tool)
{
        struct s390_cpumsf *sf = container_of(session->auxtrace,
                                              struct s390_cpumsf,
                                              auxtrace);
        u64 timestamp = sample->time;
        struct evsel *ev_bc000;

        int err = 0;

        if (dump_trace)
                return 0;

        if (!tool->ordered_events) {
                pr_err("s390 Auxiliary Trace requires ordered events\n");
                return -EINVAL;
        }

        if (event->header.type == PERF_RECORD_SAMPLE &&
            sample->raw_size) {
                /* Handle event with raw data */
                ev_bc000 = evlist__event2evsel(session->evlist, event);
                if (ev_bc000 &&
                    ev_bc000->core.attr.config == PERF_EVENT_CPUM_CF_DIAG)
                        err = s390_cpumcf_dumpctr(sf, sample);
                return err;
        }

        if (event->header.type == PERF_RECORD_AUX &&
            event->aux.flags & PERF_AUX_FLAG_TRUNCATED)
                return s390_cpumsf_lost(sf, sample);

        if (timestamp) {
                err = s390_cpumsf_update_queues(sf, timestamp);
                if (!err)
                        err = s390_cpumsf_process_queues(sf, timestamp);
        }
        return err;
}

struct s390_cpumsf_synth {
        struct perf_tool cpumsf_tool;
        struct perf_session *session;
};

static int
s390_cpumsf_process_auxtrace_event(struct perf_session *session,
                                   union perf_event *event __maybe_unused,
                                   struct perf_tool *tool __maybe_unused)
{
        struct s390_cpumsf *sf = container_of(session->auxtrace,
                                              struct s390_cpumsf,
                                              auxtrace);

        int fd = perf_data__fd(session->data);
        struct auxtrace_buffer *buffer;
        off_t data_offset;
        int err;

        if (sf->data_queued)
                return 0;

        if (perf_data__is_pipe(session->data)) {
                data_offset = 0;
        } else {
                data_offset = lseek(fd, 0, SEEK_CUR);
                if (data_offset == -1)
                        return -errno;
        }

        err = auxtrace_queues__add_event(&sf->queues, session, event,
                                         data_offset, &buffer);
        if (err)
                return err;

        /* Dump here after copying piped trace out of the pipe */
        if (dump_trace) {
                if (auxtrace_buffer__get_data(buffer, fd)) {
                        s390_cpumsf_dump_event(sf, buffer->data,
                                               buffer->size);
                        auxtrace_buffer__put_data(buffer);
                }
        }
        return 0;
}

static void s390_cpumsf_free_events(struct perf_session *session __maybe_unused)

{
}

static int s390_cpumsf_flush(struct perf_session *session __maybe_unused,
                             struct perf_tool *tool __maybe_unused)
{
        return 0;
}

static void s390_cpumsf_free_queues(struct perf_session *session)
{
        struct s390_cpumsf *sf = container_of(session->auxtrace,
                                              struct s390_cpumsf,
                                              auxtrace);
        struct auxtrace_queues *queues = &sf->queues;
        unsigned int i;

        for (i = 0; i < queues->nr_queues; i++) {
                struct s390_cpumsf_queue *sfq = (struct s390_cpumsf_queue *)
                                                queues->queue_array[i].priv;

                if (sfq != NULL) {
                        if (sfq->logfile) {
                                fclose(sfq->logfile);
                                sfq->logfile = NULL;
                        }
                        if (sfq->logfile_ctr) {
                                fclose(sfq->logfile_ctr);
                                sfq->logfile_ctr = NULL;
                        }
                }
                zfree(&queues->queue_array[i].priv);
        }
        auxtrace_queues__free(queues);
}

static void s390_cpumsf_free(struct perf_session *session)
{
        struct s390_cpumsf *sf = container_of(session->auxtrace,
                                              struct s390_cpumsf,
                                              auxtrace);

        auxtrace_heap__free(&sf->heap);
        s390_cpumsf_free_queues(session);
        session->auxtrace = NULL;
        zfree(&sf->logdir);
        free(sf);
}

static bool
s390_cpumsf_evsel_is_auxtrace(struct perf_session *session __maybe_unused,
                              struct evsel *evsel)
{
        return evsel->core.attr.type == PERF_TYPE_RAW &&
               evsel->core.attr.config == PERF_EVENT_CPUM_SF_DIAG;
}

static int s390_cpumsf_get_type(const char *cpuid)
{
        int ret, family = 0;

        ret = sscanf(cpuid, "%*[^,],%u", &family);
        return (ret == 1) ? family : 0;
}

/* Check itrace options set on perf report command.
 * Return true, if none are set or all options specified can be
 * handled on s390 (currently only option 'd' for logging.
 * Return false otherwise.
 */
static bool check_auxtrace_itrace(struct itrace_synth_opts *itops)
{
        bool ison = false;

        if (!itops || !itops->set)
                return true;
        ison = itops->inject || itops->instructions || itops->branches ||
                itops->transactions || itops->ptwrites ||
                itops->pwr_events || itops->errors ||
                itops->dont_decode || itops->calls || itops->returns ||
                itops->callchain || itops->thread_stack ||
                itops->last_branch || itops->add_callchain ||
                itops->add_last_branch;
        if (!ison)
                return true;
        pr_err("Unsupported --itrace options specified\n");
        return false;
}

/* Check for AUXTRACE dump directory if it is needed.
 * On failure print an error message but continue.
 * Return 0 on wrong keyword in config file and 1 otherwise.
 */
static int s390_cpumsf__config(const char *var, const char *value, void *cb)
{
        struct s390_cpumsf *sf = cb;
        struct stat stbuf;
        int rc;

        if (strcmp(var, "auxtrace.dumpdir"))
                return 0;
        sf->logdir = strdup(value);
        if (sf->logdir == NULL) {
                pr_err("Failed to find auxtrace log directory %s,"
                       " continue with current directory...\n", value);
                return 1;
        }
        rc = stat(sf->logdir, &stbuf);
        if (rc == -1 || !S_ISDIR(stbuf.st_mode)) {
                pr_err("Missing auxtrace log directory %s,"
                       " continue with current directory...\n", value);
                zfree(&sf->logdir);
        }
        return 1;
}

int s390_cpumsf_process_auxtrace_info(union perf_event *event,
                                      struct perf_session *session)
{
        struct perf_record_auxtrace_info *auxtrace_info = &event->auxtrace_info;
        struct s390_cpumsf *sf;
        int err;

        if (auxtrace_info->header.size < sizeof(struct perf_record_auxtrace_info))
                return -EINVAL;

        sf = zalloc(sizeof(struct s390_cpumsf));
        if (sf == NULL)
                return -ENOMEM;

        if (!check_auxtrace_itrace(session->itrace_synth_opts)) {
                err = -EINVAL;
                goto err_free;
        }
        sf->use_logfile = session->itrace_synth_opts->log;
        if (sf->use_logfile)
                perf_config(s390_cpumsf__config, sf);

        err = auxtrace_queues__init(&sf->queues);
        if (err)
                goto err_free;

        sf->session = session;
        sf->machine = &session->machines.host; /* No kvm support */
        sf->auxtrace_type = auxtrace_info->type;
        sf->pmu_type = PERF_TYPE_RAW;
        sf->machine_type = s390_cpumsf_get_type(session->evlist->env->cpuid);

        sf->auxtrace.process_event = s390_cpumsf_process_event;
        sf->auxtrace.process_auxtrace_event = s390_cpumsf_process_auxtrace_event;
        sf->auxtrace.flush_events = s390_cpumsf_flush;
        sf->auxtrace.free_events = s390_cpumsf_free_events;
        sf->auxtrace.free = s390_cpumsf_free;
        sf->auxtrace.evsel_is_auxtrace = s390_cpumsf_evsel_is_auxtrace;
        session->auxtrace = &sf->auxtrace;

        if (dump_trace)
                return 0;

        err = auxtrace_queues__process_index(&sf->queues, session);
        if (err)
                goto err_free_queues;

        if (sf->queues.populated)
                sf->data_queued = true;

        return 0;

err_free_queues:
        auxtrace_queues__free(&sf->queues);
        session->auxtrace = NULL;
err_free:
        zfree(&sf->logdir);
        free(sf);
        return err;
}