linux/arch/powerpc/perf/hv-24x7.c
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   1/*
   2 * Hypervisor supplied "24x7" performance counter support
   3 *
   4 * Author: Cody P Schafer <cody@linux.vnet.ibm.com>
   5 * Copyright 2014 IBM Corporation.
   6 *
   7 * This program is free software; you can redistribute it and/or
   8 * modify it under the terms of the GNU General Public License
   9 * as published by the Free Software Foundation; either version
  10 * 2 of the License, or (at your option) any later version.
  11 */
  12
  13#define pr_fmt(fmt) "hv-24x7: " fmt
  14
  15#include <linux/perf_event.h>
  16#include <linux/rbtree.h>
  17#include <linux/module.h>
  18#include <linux/slab.h>
  19#include <linux/vmalloc.h>
  20
  21#include <asm/firmware.h>
  22#include <asm/hvcall.h>
  23#include <asm/io.h>
  24#include <linux/byteorder/generic.h>
  25
  26#include "hv-24x7.h"
  27#include "hv-24x7-catalog.h"
  28#include "hv-common.h"
  29
  30static const char *event_domain_suffix(unsigned domain)
  31{
  32        switch (domain) {
  33#define DOMAIN(n, v, x, c)              \
  34        case HV_PERF_DOMAIN_##n:        \
  35                return "__" #n;
  36#include "hv-24x7-domains.h"
  37#undef DOMAIN
  38        default:
  39                WARN(1, "unknown domain %d\n", domain);
  40                return "__UNKNOWN_DOMAIN_SUFFIX";
  41        }
  42}
  43
  44static bool domain_is_valid(unsigned domain)
  45{
  46        switch (domain) {
  47#define DOMAIN(n, v, x, c)              \
  48        case HV_PERF_DOMAIN_##n:        \
  49                /* fall through */
  50#include "hv-24x7-domains.h"
  51#undef DOMAIN
  52                return true;
  53        default:
  54                return false;
  55        }
  56}
  57
  58static bool is_physical_domain(unsigned domain)
  59{
  60        switch (domain) {
  61#define DOMAIN(n, v, x, c)              \
  62        case HV_PERF_DOMAIN_##n:        \
  63                return c;
  64#include "hv-24x7-domains.h"
  65#undef DOMAIN
  66        default:
  67                return false;
  68        }
  69}
  70
  71static bool catalog_entry_domain_is_valid(unsigned domain)
  72{
  73        return is_physical_domain(domain);
  74}
  75
  76/*
  77 * TODO: Merging events:
  78 * - Think of the hcall as an interface to a 4d array of counters:
  79 *   - x = domains
  80 *   - y = indexes in the domain (core, chip, vcpu, node, etc)
  81 *   - z = offset into the counter space
  82 *   - w = lpars (guest vms, "logical partitions")
  83 * - A single request is: x,y,y_last,z,z_last,w,w_last
  84 *   - this means we can retrieve a rectangle of counters in y,z for a single x.
  85 *
  86 * - Things to consider (ignoring w):
  87 *   - input  cost_per_request = 16
  88 *   - output cost_per_result(ys,zs)  = 8 + 8 * ys + ys * zs
  89 *   - limited number of requests per hcall (must fit into 4K bytes)
  90 *     - 4k = 16 [buffer header] - 16 [request size] * request_count
  91 *     - 255 requests per hcall
  92 *   - sometimes it will be more efficient to read extra data and discard
  93 */
  94
  95/*
  96 * Example usage:
  97 *  perf stat -e 'hv_24x7/domain=2,offset=8,vcpu=0,lpar=0xffffffff/'
  98 */
  99
 100/* u3 0-6, one of HV_24X7_PERF_DOMAIN */
 101EVENT_DEFINE_RANGE_FORMAT(domain, config, 0, 3);
 102/* u16 */
 103EVENT_DEFINE_RANGE_FORMAT(core, config, 16, 31);
 104EVENT_DEFINE_RANGE_FORMAT(vcpu, config, 16, 31);
 105/* u32, see "data_offset" */
 106EVENT_DEFINE_RANGE_FORMAT(offset, config, 32, 63);
 107/* u16 */
 108EVENT_DEFINE_RANGE_FORMAT(lpar, config1, 0, 15);
 109
 110EVENT_DEFINE_RANGE(reserved1, config,   4, 15);
 111EVENT_DEFINE_RANGE(reserved2, config1, 16, 63);
 112EVENT_DEFINE_RANGE(reserved3, config2,  0, 63);
 113
 114static struct attribute *format_attrs[] = {
 115        &format_attr_domain.attr,
 116        &format_attr_offset.attr,
 117        &format_attr_core.attr,
 118        &format_attr_vcpu.attr,
 119        &format_attr_lpar.attr,
 120        NULL,
 121};
 122
 123static struct attribute_group format_group = {
 124        .name = "format",
 125        .attrs = format_attrs,
 126};
 127
 128static struct attribute_group event_group = {
 129        .name = "events",
 130        /* .attrs is set in init */
 131};
 132
 133static struct attribute_group event_desc_group = {
 134        .name = "event_descs",
 135        /* .attrs is set in init */
 136};
 137
 138static struct attribute_group event_long_desc_group = {
 139        .name = "event_long_descs",
 140        /* .attrs is set in init */
 141};
 142
 143static struct kmem_cache *hv_page_cache;
 144
 145static char *event_name(struct hv_24x7_event_data *ev, int *len)
 146{
 147        *len = be16_to_cpu(ev->event_name_len) - 2;
 148        return (char *)ev->remainder;
 149}
 150
 151static char *event_desc(struct hv_24x7_event_data *ev, int *len)
 152{
 153        unsigned nl = be16_to_cpu(ev->event_name_len);
 154        __be16 *desc_len = (__be16 *)(ev->remainder + nl - 2);
 155        *len = be16_to_cpu(*desc_len) - 2;
 156        return (char *)ev->remainder + nl;
 157}
 158
 159static char *event_long_desc(struct hv_24x7_event_data *ev, int *len)
 160{
 161        unsigned nl = be16_to_cpu(ev->event_name_len);
 162        __be16 *desc_len_ = (__be16 *)(ev->remainder + nl - 2);
 163        unsigned desc_len = be16_to_cpu(*desc_len_);
 164        __be16 *long_desc_len = (__be16 *)(ev->remainder + nl + desc_len - 2);
 165        *len = be16_to_cpu(*long_desc_len) - 2;
 166        return (char *)ev->remainder + nl + desc_len;
 167}
 168
 169static bool event_fixed_portion_is_within(struct hv_24x7_event_data *ev,
 170                                          void *end)
 171{
 172        void *start = ev;
 173
 174        return (start + offsetof(struct hv_24x7_event_data, remainder)) < end;
 175}
 176
 177/*
 178 * Things we don't check:
 179 *  - padding for desc, name, and long/detailed desc is required to be '\0'
 180 *    bytes.
 181 *
 182 *  Return NULL if we pass end,
 183 *  Otherwise return the address of the byte just following the event.
 184 */
 185static void *event_end(struct hv_24x7_event_data *ev, void *end)
 186{
 187        void *start = ev;
 188        __be16 *dl_, *ldl_;
 189        unsigned dl, ldl;
 190        unsigned nl = be16_to_cpu(ev->event_name_len);
 191
 192        if (nl < 2) {
 193                pr_debug("%s: name length too short: %d", __func__, nl);
 194                return NULL;
 195        }
 196
 197        if (start + nl > end) {
 198                pr_debug("%s: start=%p + nl=%u > end=%p",
 199                                __func__, start, nl, end);
 200                return NULL;
 201        }
 202
 203        dl_ = (__be16 *)(ev->remainder + nl - 2);
 204        if (!IS_ALIGNED((uintptr_t)dl_, 2))
 205                pr_warn("desc len not aligned %p", dl_);
 206        dl = be16_to_cpu(*dl_);
 207        if (dl < 2) {
 208                pr_debug("%s: desc len too short: %d", __func__, dl);
 209                return NULL;
 210        }
 211
 212        if (start + nl + dl > end) {
 213                pr_debug("%s: (start=%p + nl=%u + dl=%u)=%p > end=%p",
 214                                __func__, start, nl, dl, start + nl + dl, end);
 215                return NULL;
 216        }
 217
 218        ldl_ = (__be16 *)(ev->remainder + nl + dl - 2);
 219        if (!IS_ALIGNED((uintptr_t)ldl_, 2))
 220                pr_warn("long desc len not aligned %p", ldl_);
 221        ldl = be16_to_cpu(*ldl_);
 222        if (ldl < 2) {
 223                pr_debug("%s: long desc len too short (ldl=%u)",
 224                                __func__, ldl);
 225                return NULL;
 226        }
 227
 228        if (start + nl + dl + ldl > end) {
 229                pr_debug("%s: start=%p + nl=%u + dl=%u + ldl=%u > end=%p",
 230                                __func__, start, nl, dl, ldl, end);
 231                return NULL;
 232        }
 233
 234        return start + nl + dl + ldl;
 235}
 236
 237static unsigned long h_get_24x7_catalog_page_(unsigned long phys_4096,
 238                                              unsigned long version,
 239                                              unsigned long index)
 240{
 241        pr_devel("h_get_24x7_catalog_page(0x%lx, %lu, %lu)",
 242                        phys_4096,
 243                        version,
 244                        index);
 245        WARN_ON(!IS_ALIGNED(phys_4096, 4096));
 246        return plpar_hcall_norets(H_GET_24X7_CATALOG_PAGE,
 247                        phys_4096,
 248                        version,
 249                        index);
 250}
 251
 252static unsigned long h_get_24x7_catalog_page(char page[],
 253                                             u64 version, u32 index)
 254{
 255        return h_get_24x7_catalog_page_(virt_to_phys(page),
 256                                        version, index);
 257}
 258
 259static unsigned core_domains[] = {
 260        HV_PERF_DOMAIN_PHYS_CORE,
 261        HV_PERF_DOMAIN_VCPU_HOME_CORE,
 262        HV_PERF_DOMAIN_VCPU_HOME_CHIP,
 263        HV_PERF_DOMAIN_VCPU_HOME_NODE,
 264        HV_PERF_DOMAIN_VCPU_REMOTE_NODE,
 265};
 266/* chip event data always yeilds a single event, core yeilds multiple */
 267#define MAX_EVENTS_PER_EVENT_DATA ARRAY_SIZE(core_domains)
 268
 269static char *event_fmt(struct hv_24x7_event_data *event, unsigned domain)
 270{
 271        const char *sindex;
 272        const char *lpar;
 273
 274        if (is_physical_domain(domain)) {
 275                lpar = "0x0";
 276                sindex = "core";
 277        } else {
 278                lpar = "?";
 279                sindex = "vcpu";
 280        }
 281
 282        return kasprintf(GFP_KERNEL,
 283                        "domain=0x%x,offset=0x%x,%s=?,lpar=%s",
 284                        domain,
 285                        be16_to_cpu(event->event_counter_offs) +
 286                                be16_to_cpu(event->event_group_record_offs),
 287                        sindex,
 288                        lpar);
 289}
 290
 291/* Avoid trusting fw to NUL terminate strings */
 292static char *memdup_to_str(char *maybe_str, int max_len, gfp_t gfp)
 293{
 294        return kasprintf(gfp, "%.*s", max_len, maybe_str);
 295}
 296
 297static ssize_t device_show_string(struct device *dev,
 298                struct device_attribute *attr, char *buf)
 299{
 300        struct dev_ext_attribute *d;
 301
 302        d = container_of(attr, struct dev_ext_attribute, attr);
 303        return sprintf(buf, "%s\n", (char *)d->var);
 304}
 305
 306static struct attribute *device_str_attr_create_(char *name, char *str)
 307{
 308        struct dev_ext_attribute *attr = kzalloc(sizeof(*attr), GFP_KERNEL);
 309
 310        if (!attr)
 311                return NULL;
 312
 313        attr->var = str;
 314        attr->attr.attr.name = name;
 315        attr->attr.attr.mode = 0444;
 316        attr->attr.show = device_show_string;
 317        return &attr->attr.attr;
 318}
 319
 320static struct attribute *device_str_attr_create(char *name, int name_max,
 321                                                int name_nonce,
 322                                                char *str, size_t str_max)
 323{
 324        char *n;
 325        char *s = memdup_to_str(str, str_max, GFP_KERNEL);
 326        struct attribute *a;
 327
 328        if (!s)
 329                return NULL;
 330
 331        if (!name_nonce)
 332                n = kasprintf(GFP_KERNEL, "%.*s", name_max, name);
 333        else
 334                n = kasprintf(GFP_KERNEL, "%.*s__%d", name_max, name,
 335                                        name_nonce);
 336        if (!n)
 337                goto out_s;
 338
 339        a = device_str_attr_create_(n, s);
 340        if (!a)
 341                goto out_n;
 342
 343        return a;
 344out_n:
 345        kfree(n);
 346out_s:
 347        kfree(s);
 348        return NULL;
 349}
 350
 351static void device_str_attr_destroy(struct attribute *attr)
 352{
 353        struct dev_ext_attribute *d;
 354
 355        d = container_of(attr, struct dev_ext_attribute, attr.attr);
 356        kfree(d->var);
 357        kfree(d->attr.attr.name);
 358        kfree(d);
 359}
 360
 361static struct attribute *event_to_attr(unsigned ix,
 362                                       struct hv_24x7_event_data *event,
 363                                       unsigned domain,
 364                                       int nonce)
 365{
 366        int event_name_len;
 367        char *ev_name, *a_ev_name, *val;
 368        const char *ev_suffix;
 369        struct attribute *attr;
 370
 371        if (!domain_is_valid(domain)) {
 372                pr_warn("catalog event %u has invalid domain %u\n",
 373                                ix, domain);
 374                return NULL;
 375        }
 376
 377        val = event_fmt(event, domain);
 378        if (!val)
 379                return NULL;
 380
 381        ev_suffix = event_domain_suffix(domain);
 382        ev_name = event_name(event, &event_name_len);
 383        if (!nonce)
 384                a_ev_name = kasprintf(GFP_KERNEL, "%.*s%s",
 385                                (int)event_name_len, ev_name, ev_suffix);
 386        else
 387                a_ev_name = kasprintf(GFP_KERNEL, "%.*s%s__%d",
 388                                (int)event_name_len, ev_name, ev_suffix, nonce);
 389
 390
 391        if (!a_ev_name)
 392                goto out_val;
 393
 394        attr = device_str_attr_create_(a_ev_name, val);
 395        if (!attr)
 396                goto out_name;
 397
 398        return attr;
 399out_name:
 400        kfree(a_ev_name);
 401out_val:
 402        kfree(val);
 403        return NULL;
 404}
 405
 406static struct attribute *event_to_desc_attr(struct hv_24x7_event_data *event,
 407                                int nonce)
 408{
 409        int nl, dl;
 410        char *name = event_name(event, &nl);
 411        char *desc = event_desc(event, &dl);
 412
 413        /* If there isn't a description, don't create the sysfs file */
 414        if (!dl)
 415                return NULL;
 416
 417        return device_str_attr_create(name, nl, nonce, desc, dl);
 418}
 419
 420static struct attribute *
 421event_to_long_desc_attr(struct hv_24x7_event_data *event, int nonce)
 422{
 423        int nl, dl;
 424        char *name = event_name(event, &nl);
 425        char *desc = event_long_desc(event, &dl);
 426
 427        /* If there isn't a description, don't create the sysfs file */
 428        if (!dl)
 429                return NULL;
 430
 431        return device_str_attr_create(name, nl, nonce, desc, dl);
 432}
 433
 434static ssize_t event_data_to_attrs(unsigned ix, struct attribute **attrs,
 435                struct hv_24x7_event_data *event, int nonce)
 436{
 437        unsigned i;
 438
 439        switch (event->domain) {
 440        case HV_PERF_DOMAIN_PHYS_CHIP:
 441                *attrs = event_to_attr(ix, event, event->domain, nonce);
 442                return 1;
 443        case HV_PERF_DOMAIN_PHYS_CORE:
 444                for (i = 0; i < ARRAY_SIZE(core_domains); i++) {
 445                        attrs[i] = event_to_attr(ix, event, core_domains[i],
 446                                                nonce);
 447                        if (!attrs[i]) {
 448                                pr_warn("catalog event %u: individual attr %u "
 449                                        "creation failure\n", ix, i);
 450                                for (; i; i--)
 451                                        device_str_attr_destroy(attrs[i - 1]);
 452                                return -1;
 453                        }
 454                }
 455                return i;
 456        default:
 457                pr_warn("catalog event %u: domain %u is not allowed in the "
 458                                "catalog\n", ix, event->domain);
 459                return -1;
 460        }
 461}
 462
 463static size_t event_to_attr_ct(struct hv_24x7_event_data *event)
 464{
 465        switch (event->domain) {
 466        case HV_PERF_DOMAIN_PHYS_CHIP:
 467                return 1;
 468        case HV_PERF_DOMAIN_PHYS_CORE:
 469                return ARRAY_SIZE(core_domains);
 470        default:
 471                return 0;
 472        }
 473}
 474
 475static unsigned long vmalloc_to_phys(void *v)
 476{
 477        struct page *p = vmalloc_to_page(v);
 478
 479        BUG_ON(!p);
 480        return page_to_phys(p) + offset_in_page(v);
 481}
 482
 483/* */
 484struct event_uniq {
 485        struct rb_node node;
 486        const char *name;
 487        int nl;
 488        unsigned ct;
 489        unsigned domain;
 490};
 491
 492static int memord(const void *d1, size_t s1, const void *d2, size_t s2)
 493{
 494        if (s1 < s2)
 495                return 1;
 496        if (s2 > s1)
 497                return -1;
 498
 499        return memcmp(d1, d2, s1);
 500}
 501
 502static int ev_uniq_ord(const void *v1, size_t s1, unsigned d1, const void *v2,
 503                                        size_t s2, unsigned d2)
 504{
 505        int r = memord(v1, s1, v2, s2);
 506
 507        if (r)
 508                return r;
 509        if (d1 > d2)
 510                return 1;
 511        if (d2 > d1)
 512                return -1;
 513        return 0;
 514}
 515
 516static int event_uniq_add(struct rb_root *root, const char *name, int nl,
 517                                unsigned domain)
 518{
 519        struct rb_node **new = &(root->rb_node), *parent = NULL;
 520        struct event_uniq *data;
 521
 522        /* Figure out where to put new node */
 523        while (*new) {
 524                struct event_uniq *it;
 525                int result;
 526
 527                it = container_of(*new, struct event_uniq, node);
 528                result = ev_uniq_ord(name, nl, domain, it->name, it->nl,
 529                                        it->domain);
 530
 531                parent = *new;
 532                if (result < 0)
 533                        new = &((*new)->rb_left);
 534                else if (result > 0)
 535                        new = &((*new)->rb_right);
 536                else {
 537                        it->ct++;
 538                        pr_info("found a duplicate event %.*s, ct=%u\n", nl,
 539                                                name, it->ct);
 540                        return it->ct;
 541                }
 542        }
 543
 544        data = kmalloc(sizeof(*data), GFP_KERNEL);
 545        if (!data)
 546                return -ENOMEM;
 547
 548        *data = (struct event_uniq) {
 549                .name = name,
 550                .nl = nl,
 551                .ct = 0,
 552                .domain = domain,
 553        };
 554
 555        /* Add new node and rebalance tree. */
 556        rb_link_node(&data->node, parent, new);
 557        rb_insert_color(&data->node, root);
 558
 559        /* data->ct */
 560        return 0;
 561}
 562
 563static void event_uniq_destroy(struct rb_root *root)
 564{
 565        /*
 566         * the strings we point to are in the giant block of memory filled by
 567         * the catalog, and are freed separately.
 568         */
 569        struct event_uniq *pos, *n;
 570
 571        rbtree_postorder_for_each_entry_safe(pos, n, root, node)
 572                kfree(pos);
 573}
 574
 575
 576/*
 577 * ensure the event structure's sizes are self consistent and don't cause us to
 578 * read outside of the event
 579 *
 580 * On success, return the event length in bytes.
 581 * Otherwise, return -1 (and print as appropriate).
 582 */
 583static ssize_t catalog_event_len_validate(struct hv_24x7_event_data *event,
 584                                          size_t event_idx,
 585                                          size_t event_data_bytes,
 586                                          size_t event_entry_count,
 587                                          size_t offset, void *end)
 588{
 589        ssize_t ev_len;
 590        void *ev_end, *calc_ev_end;
 591
 592        if (offset >= event_data_bytes)
 593                return -1;
 594
 595        if (event_idx >= event_entry_count) {
 596                pr_devel("catalog event data has %zu bytes of padding after last event\n",
 597                                event_data_bytes - offset);
 598                return -1;
 599        }
 600
 601        if (!event_fixed_portion_is_within(event, end)) {
 602                pr_warn("event %zu fixed portion is not within range\n",
 603                                event_idx);
 604                return -1;
 605        }
 606
 607        ev_len = be16_to_cpu(event->length);
 608
 609        if (ev_len % 16)
 610                pr_info("event %zu has length %zu not divisible by 16: event=%pK\n",
 611                                event_idx, ev_len, event);
 612
 613        ev_end = (__u8 *)event + ev_len;
 614        if (ev_end > end) {
 615                pr_warn("event %zu has .length=%zu, ends after buffer end: ev_end=%pK > end=%pK, offset=%zu\n",
 616                                event_idx, ev_len, ev_end, end,
 617                                offset);
 618                return -1;
 619        }
 620
 621        calc_ev_end = event_end(event, end);
 622        if (!calc_ev_end) {
 623                pr_warn("event %zu has a calculated length which exceeds buffer length %zu: event=%pK end=%pK, offset=%zu\n",
 624                        event_idx, event_data_bytes, event, end,
 625                        offset);
 626                return -1;
 627        }
 628
 629        if (calc_ev_end > ev_end) {
 630                pr_warn("event %zu exceeds it's own length: event=%pK, end=%pK, offset=%zu, calc_ev_end=%pK\n",
 631                        event_idx, event, ev_end, offset, calc_ev_end);
 632                return -1;
 633        }
 634
 635        return ev_len;
 636}
 637
 638#define MAX_4K (SIZE_MAX / 4096)
 639
 640static void create_events_from_catalog(struct attribute ***events_,
 641                struct attribute ***event_descs_,
 642                struct attribute ***event_long_descs_)
 643{
 644        unsigned long hret;
 645        size_t catalog_len, catalog_page_len, event_entry_count,
 646               event_data_len, event_data_offs,
 647               event_data_bytes, junk_events, event_idx, event_attr_ct, i,
 648               attr_max, event_idx_last, desc_ct, long_desc_ct;
 649        ssize_t ct, ev_len;
 650        uint32_t catalog_version_num;
 651        struct attribute **events, **event_descs, **event_long_descs;
 652        struct hv_24x7_catalog_page_0 *page_0 =
 653                kmem_cache_alloc(hv_page_cache, GFP_KERNEL);
 654        void *page = page_0;
 655        void *event_data, *end;
 656        struct hv_24x7_event_data *event;
 657        struct rb_root ev_uniq = RB_ROOT;
 658
 659        if (!page)
 660                goto e_out;
 661
 662        hret = h_get_24x7_catalog_page(page, 0, 0);
 663        if (hret)
 664                goto e_free;
 665
 666        catalog_version_num = be64_to_cpu(page_0->version);
 667        catalog_page_len = be32_to_cpu(page_0->length);
 668
 669        if (MAX_4K < catalog_page_len) {
 670                pr_err("invalid page count: %zu\n", catalog_page_len);
 671                goto e_free;
 672        }
 673
 674        catalog_len = catalog_page_len * 4096;
 675
 676        event_entry_count = be16_to_cpu(page_0->event_entry_count);
 677        event_data_offs   = be16_to_cpu(page_0->event_data_offs);
 678        event_data_len    = be16_to_cpu(page_0->event_data_len);
 679
 680        pr_devel("cv %zu cl %zu eec %zu edo %zu edl %zu\n",
 681                        (size_t)catalog_version_num, catalog_len,
 682                        event_entry_count, event_data_offs, event_data_len);
 683
 684        if ((MAX_4K < event_data_len)
 685                        || (MAX_4K < event_data_offs)
 686                        || (MAX_4K - event_data_offs < event_data_len)) {
 687                pr_err("invalid event data offs %zu and/or len %zu\n",
 688                                event_data_offs, event_data_len);
 689                goto e_free;
 690        }
 691
 692        if ((event_data_offs + event_data_len) > catalog_page_len) {
 693                pr_err("event data %zu-%zu does not fit inside catalog 0-%zu\n",
 694                                event_data_offs,
 695                                event_data_offs + event_data_len,
 696                                catalog_page_len);
 697                goto e_free;
 698        }
 699
 700        if (SIZE_MAX / MAX_EVENTS_PER_EVENT_DATA - 1 < event_entry_count) {
 701                pr_err("event_entry_count %zu is invalid\n",
 702                                event_entry_count);
 703                goto e_free;
 704        }
 705
 706        event_data_bytes = event_data_len * 4096;
 707
 708        /*
 709         * event data can span several pages, events can cross between these
 710         * pages. Use vmalloc to make this easier.
 711         */
 712        event_data = vmalloc(event_data_bytes);
 713        if (!event_data) {
 714                pr_err("could not allocate event data\n");
 715                goto e_free;
 716        }
 717
 718        end = event_data + event_data_bytes;
 719
 720        /*
 721         * using vmalloc_to_phys() like this only works if PAGE_SIZE is
 722         * divisible by 4096
 723         */
 724        BUILD_BUG_ON(PAGE_SIZE % 4096);
 725
 726        for (i = 0; i < event_data_len; i++) {
 727                hret = h_get_24x7_catalog_page_(
 728                                vmalloc_to_phys(event_data + i * 4096),
 729                                catalog_version_num,
 730                                i + event_data_offs);
 731                if (hret) {
 732                        pr_err("failed to get event data in page %zu\n",
 733                                        i + event_data_offs);
 734                        goto e_event_data;
 735                }
 736        }
 737
 738        /*
 739         * scan the catalog to determine the number of attributes we need, and
 740         * verify it at the same time.
 741         */
 742        for (junk_events = 0, event = event_data, event_idx = 0, attr_max = 0;
 743             ;
 744             event_idx++, event = (void *)event + ev_len) {
 745                size_t offset = (void *)event - (void *)event_data;
 746                char *name;
 747                int nl;
 748
 749                ev_len = catalog_event_len_validate(event, event_idx,
 750                                                    event_data_bytes,
 751                                                    event_entry_count,
 752                                                    offset, end);
 753                if (ev_len < 0)
 754                        break;
 755
 756                name = event_name(event, &nl);
 757
 758                if (event->event_group_record_len == 0) {
 759                        pr_devel("invalid event %zu (%.*s): group_record_len == 0, skipping\n",
 760                                        event_idx, nl, name);
 761                        junk_events++;
 762                        continue;
 763                }
 764
 765                if (!catalog_entry_domain_is_valid(event->domain)) {
 766                        pr_info("event %zu (%.*s) has invalid domain %d\n",
 767                                        event_idx, nl, name, event->domain);
 768                        junk_events++;
 769                        continue;
 770                }
 771
 772                attr_max += event_to_attr_ct(event);
 773        }
 774
 775        event_idx_last = event_idx;
 776        if (event_idx_last != event_entry_count)
 777                pr_warn("event buffer ended before listed # of events were parsed (got %zu, wanted %zu, junk %zu)\n",
 778                                event_idx_last, event_entry_count, junk_events);
 779
 780        events = kmalloc_array(attr_max + 1, sizeof(*events), GFP_KERNEL);
 781        if (!events)
 782                goto e_event_data;
 783
 784        event_descs = kmalloc_array(event_idx + 1, sizeof(*event_descs),
 785                                GFP_KERNEL);
 786        if (!event_descs)
 787                goto e_event_attrs;
 788
 789        event_long_descs = kmalloc_array(event_idx + 1,
 790                        sizeof(*event_long_descs), GFP_KERNEL);
 791        if (!event_long_descs)
 792                goto e_event_descs;
 793
 794        /* Iterate over the catalog filling in the attribute vector */
 795        for (junk_events = 0, event_attr_ct = 0, desc_ct = 0, long_desc_ct = 0,
 796                                event = event_data, event_idx = 0;
 797                        event_idx < event_idx_last;
 798                        event_idx++, ev_len = be16_to_cpu(event->length),
 799                                event = (void *)event + ev_len) {
 800                char *name;
 801                int nl;
 802                int nonce;
 803                /*
 804                 * these are the only "bad" events that are intermixed and that
 805                 * we can ignore without issue. make sure to skip them here
 806                 */
 807                if (event->event_group_record_len == 0)
 808                        continue;
 809                if (!catalog_entry_domain_is_valid(event->domain))
 810                        continue;
 811
 812                name  = event_name(event, &nl);
 813                nonce = event_uniq_add(&ev_uniq, name, nl, event->domain);
 814                ct    = event_data_to_attrs(event_idx, events + event_attr_ct,
 815                                            event, nonce);
 816                if (ct <= 0) {
 817                        pr_warn("event %zu (%.*s) creation failure, skipping\n",
 818                                event_idx, nl, name);
 819                        junk_events++;
 820                } else {
 821                        event_attr_ct += ct;
 822                        event_descs[desc_ct] = event_to_desc_attr(event, nonce);
 823                        if (event_descs[desc_ct])
 824                                desc_ct++;
 825                        event_long_descs[long_desc_ct] =
 826                                        event_to_long_desc_attr(event, nonce);
 827                        if (event_long_descs[long_desc_ct])
 828                                long_desc_ct++;
 829                }
 830        }
 831
 832        pr_info("read %zu catalog entries, created %zu event attrs (%zu failures), %zu descs\n",
 833                        event_idx, event_attr_ct, junk_events, desc_ct);
 834
 835        events[event_attr_ct] = NULL;
 836        event_descs[desc_ct] = NULL;
 837        event_long_descs[long_desc_ct] = NULL;
 838
 839        event_uniq_destroy(&ev_uniq);
 840        vfree(event_data);
 841        kmem_cache_free(hv_page_cache, page);
 842
 843        *events_ = events;
 844        *event_descs_ = event_descs;
 845        *event_long_descs_ = event_long_descs;
 846        return;
 847
 848e_event_descs:
 849        kfree(event_descs);
 850e_event_attrs:
 851        kfree(events);
 852e_event_data:
 853        vfree(event_data);
 854e_free:
 855        kmem_cache_free(hv_page_cache, page);
 856e_out:
 857        *events_ = NULL;
 858        *event_descs_ = NULL;
 859        *event_long_descs_ = NULL;
 860}
 861
 862static ssize_t catalog_read(struct file *filp, struct kobject *kobj,
 863                            struct bin_attribute *bin_attr, char *buf,
 864                            loff_t offset, size_t count)
 865{
 866        unsigned long hret;
 867        ssize_t ret = 0;
 868        size_t catalog_len = 0, catalog_page_len = 0;
 869        loff_t page_offset = 0;
 870        loff_t offset_in_page;
 871        size_t copy_len;
 872        uint64_t catalog_version_num = 0;
 873        void *page = kmem_cache_alloc(hv_page_cache, GFP_USER);
 874        struct hv_24x7_catalog_page_0 *page_0 = page;
 875        if (!page)
 876                return -ENOMEM;
 877
 878        hret = h_get_24x7_catalog_page(page, 0, 0);
 879        if (hret) {
 880                ret = -EIO;
 881                goto e_free;
 882        }
 883
 884        catalog_version_num = be64_to_cpu(page_0->version);
 885        catalog_page_len = be32_to_cpu(page_0->length);
 886        catalog_len = catalog_page_len * 4096;
 887
 888        page_offset = offset / 4096;
 889        offset_in_page = offset % 4096;
 890
 891        if (page_offset >= catalog_page_len)
 892                goto e_free;
 893
 894        if (page_offset != 0) {
 895                hret = h_get_24x7_catalog_page(page, catalog_version_num,
 896                                               page_offset);
 897                if (hret) {
 898                        ret = -EIO;
 899                        goto e_free;
 900                }
 901        }
 902
 903        copy_len = 4096 - offset_in_page;
 904        if (copy_len > count)
 905                copy_len = count;
 906
 907        memcpy(buf, page+offset_in_page, copy_len);
 908        ret = copy_len;
 909
 910e_free:
 911        if (hret)
 912                pr_err("h_get_24x7_catalog_page(ver=%lld, page=%lld) failed:"
 913                       " rc=%ld\n",
 914                       catalog_version_num, page_offset, hret);
 915        kmem_cache_free(hv_page_cache, page);
 916
 917        pr_devel("catalog_read: offset=%lld(%lld) count=%zu "
 918                        "catalog_len=%zu(%zu) => %zd\n", offset, page_offset,
 919                        count, catalog_len, catalog_page_len, ret);
 920
 921        return ret;
 922}
 923
 924#define PAGE_0_ATTR(_name, _fmt, _expr)                         \
 925static ssize_t _name##_show(struct device *dev,                 \
 926                            struct device_attribute *dev_attr,  \
 927                            char *buf)                          \
 928{                                                               \
 929        unsigned long hret;                                     \
 930        ssize_t ret = 0;                                        \
 931        void *page = kmem_cache_alloc(hv_page_cache, GFP_USER); \
 932        struct hv_24x7_catalog_page_0 *page_0 = page;           \
 933        if (!page)                                              \
 934                return -ENOMEM;                                 \
 935        hret = h_get_24x7_catalog_page(page, 0, 0);             \
 936        if (hret) {                                             \
 937                ret = -EIO;                                     \
 938                goto e_free;                                    \
 939        }                                                       \
 940        ret = sprintf(buf, _fmt, _expr);                        \
 941e_free:                                                         \
 942        kmem_cache_free(hv_page_cache, page);                   \
 943        return ret;                                             \
 944}                                                               \
 945static DEVICE_ATTR_RO(_name)
 946
 947PAGE_0_ATTR(catalog_version, "%lld\n",
 948                (unsigned long long)be64_to_cpu(page_0->version));
 949PAGE_0_ATTR(catalog_len, "%lld\n",
 950                (unsigned long long)be32_to_cpu(page_0->length) * 4096);
 951static BIN_ATTR_RO(catalog, 0/* real length varies */);
 952
 953static struct bin_attribute *if_bin_attrs[] = {
 954        &bin_attr_catalog,
 955        NULL,
 956};
 957
 958static struct attribute *if_attrs[] = {
 959        &dev_attr_catalog_len.attr,
 960        &dev_attr_catalog_version.attr,
 961        NULL,
 962};
 963
 964static struct attribute_group if_group = {
 965        .name = "interface",
 966        .bin_attrs = if_bin_attrs,
 967        .attrs = if_attrs,
 968};
 969
 970static const struct attribute_group *attr_groups[] = {
 971        &format_group,
 972        &event_group,
 973        &event_desc_group,
 974        &event_long_desc_group,
 975        &if_group,
 976        NULL,
 977};
 978
 979DEFINE_PER_CPU(char, hv_24x7_reqb[4096]) __aligned(4096);
 980DEFINE_PER_CPU(char, hv_24x7_resb[4096]) __aligned(4096);
 981
 982static unsigned long single_24x7_request(u8 domain, u32 offset, u16 ix,
 983                                         u16 lpar, u64 *res,
 984                                         bool success_expected)
 985{
 986        unsigned long ret;
 987
 988        /*
 989         * request_buffer and result_buffer are not required to be 4k aligned,
 990         * but are not allowed to cross any 4k boundary. Aligning them to 4k is
 991         * the simplest way to ensure that.
 992         */
 993        struct reqb {
 994                struct hv_24x7_request_buffer buf;
 995                struct hv_24x7_request req;
 996        } __packed *request_buffer;
 997
 998        struct {
 999                struct hv_24x7_data_result_buffer buf;
1000                struct hv_24x7_result res;
1001                struct hv_24x7_result_element elem;
1002                __be64 result;
1003        } __packed *result_buffer;
1004
1005        BUILD_BUG_ON(sizeof(*request_buffer) > 4096);
1006        BUILD_BUG_ON(sizeof(*result_buffer) > 4096);
1007
1008        request_buffer = (void *)get_cpu_var(hv_24x7_reqb);
1009        result_buffer = (void *)get_cpu_var(hv_24x7_resb);
1010
1011        memset(request_buffer, 0, 4096);
1012        memset(result_buffer, 0, 4096);
1013
1014        *request_buffer = (struct reqb) {
1015                .buf = {
1016                        .interface_version = HV_24X7_IF_VERSION_CURRENT,
1017                        .num_requests = 1,
1018                },
1019                .req = {
1020                        .performance_domain = domain,
1021                        .data_size = cpu_to_be16(8),
1022                        .data_offset = cpu_to_be32(offset),
1023                        .starting_lpar_ix = cpu_to_be16(lpar),
1024                        .max_num_lpars = cpu_to_be16(1),
1025                        .starting_ix = cpu_to_be16(ix),
1026                        .max_ix = cpu_to_be16(1),
1027                }
1028        };
1029
1030        ret = plpar_hcall_norets(H_GET_24X7_DATA,
1031                        virt_to_phys(request_buffer), sizeof(*request_buffer),
1032                        virt_to_phys(result_buffer),  sizeof(*result_buffer));
1033
1034        if (ret) {
1035                if (success_expected)
1036                        pr_err_ratelimited("hcall failed: %d %#x %#x %d => "
1037                                "0x%lx (%ld) detail=0x%x failing ix=%x\n",
1038                                domain, offset, ix, lpar, ret, ret,
1039                                result_buffer->buf.detailed_rc,
1040                                result_buffer->buf.failing_request_ix);
1041                goto out;
1042        }
1043
1044        *res = be64_to_cpu(result_buffer->result);
1045
1046out:
1047        return ret;
1048}
1049
1050static unsigned long event_24x7_request(struct perf_event *event, u64 *res,
1051                bool success_expected)
1052{
1053        u16 idx;
1054        unsigned domain = event_get_domain(event);
1055
1056        if (is_physical_domain(domain))
1057                idx = event_get_core(event);
1058        else
1059                idx = event_get_vcpu(event);
1060
1061        return single_24x7_request(event_get_domain(event),
1062                                event_get_offset(event),
1063                                idx,
1064                                event_get_lpar(event),
1065                                res,
1066                                success_expected);
1067}
1068
1069static int h_24x7_event_init(struct perf_event *event)
1070{
1071        struct hv_perf_caps caps;
1072        unsigned domain;
1073        unsigned long hret;
1074        u64 ct;
1075
1076        /* Not our event */
1077        if (event->attr.type != event->pmu->type)
1078                return -ENOENT;
1079
1080        /* Unused areas must be 0 */
1081        if (event_get_reserved1(event) ||
1082            event_get_reserved2(event) ||
1083            event_get_reserved3(event)) {
1084                pr_devel("reserved set when forbidden 0x%llx(0x%llx) 0x%llx(0x%llx) 0x%llx(0x%llx)\n",
1085                                event->attr.config,
1086                                event_get_reserved1(event),
1087                                event->attr.config1,
1088                                event_get_reserved2(event),
1089                                event->attr.config2,
1090                                event_get_reserved3(event));
1091                return -EINVAL;
1092        }
1093
1094        /* unsupported modes and filters */
1095        if (event->attr.exclude_user   ||
1096            event->attr.exclude_kernel ||
1097            event->attr.exclude_hv     ||
1098            event->attr.exclude_idle   ||
1099            event->attr.exclude_host   ||
1100            event->attr.exclude_guest)
1101                return -EINVAL;
1102
1103        /* no branch sampling */
1104        if (has_branch_stack(event))
1105                return -EOPNOTSUPP;
1106
1107        /* offset must be 8 byte aligned */
1108        if (event_get_offset(event) % 8) {
1109                pr_devel("bad alignment\n");
1110                return -EINVAL;
1111        }
1112
1113        /* Domains above 6 are invalid */
1114        domain = event_get_domain(event);
1115        if (domain > 6) {
1116                pr_devel("invalid domain %d\n", domain);
1117                return -EINVAL;
1118        }
1119
1120        hret = hv_perf_caps_get(&caps);
1121        if (hret) {
1122                pr_devel("could not get capabilities: rc=%ld\n", hret);
1123                return -EIO;
1124        }
1125
1126        /* Physical domains & other lpars require extra capabilities */
1127        if (!caps.collect_privileged && (is_physical_domain(domain) ||
1128                (event_get_lpar(event) != event_get_lpar_max()))) {
1129                pr_devel("hv permisions disallow: is_physical_domain:%d, lpar=0x%llx\n",
1130                                is_physical_domain(domain),
1131                                event_get_lpar(event));
1132                return -EACCES;
1133        }
1134
1135        /* see if the event complains */
1136        if (event_24x7_request(event, &ct, false)) {
1137                pr_devel("test hcall failed\n");
1138                return -EIO;
1139        }
1140
1141        return 0;
1142}
1143
1144static u64 h_24x7_get_value(struct perf_event *event)
1145{
1146        unsigned long ret;
1147        u64 ct;
1148        ret = event_24x7_request(event, &ct, true);
1149        if (ret)
1150                /* We checked this in event init, shouldn't fail here... */
1151                return 0;
1152
1153        return ct;
1154}
1155
1156static void h_24x7_event_update(struct perf_event *event)
1157{
1158        s64 prev;
1159        u64 now;
1160        now = h_24x7_get_value(event);
1161        prev = local64_xchg(&event->hw.prev_count, now);
1162        local64_add(now - prev, &event->count);
1163}
1164
1165static void h_24x7_event_start(struct perf_event *event, int flags)
1166{
1167        if (flags & PERF_EF_RELOAD)
1168                local64_set(&event->hw.prev_count, h_24x7_get_value(event));
1169}
1170
1171static void h_24x7_event_stop(struct perf_event *event, int flags)
1172{
1173        h_24x7_event_update(event);
1174}
1175
1176static int h_24x7_event_add(struct perf_event *event, int flags)
1177{
1178        if (flags & PERF_EF_START)
1179                h_24x7_event_start(event, flags);
1180
1181        return 0;
1182}
1183
1184static struct pmu h_24x7_pmu = {
1185        .task_ctx_nr = perf_invalid_context,
1186
1187        .name = "hv_24x7",
1188        .attr_groups = attr_groups,
1189        .event_init  = h_24x7_event_init,
1190        .add         = h_24x7_event_add,
1191        .del         = h_24x7_event_stop,
1192        .start       = h_24x7_event_start,
1193        .stop        = h_24x7_event_stop,
1194        .read        = h_24x7_event_update,
1195};
1196
1197static int hv_24x7_init(void)
1198{
1199        int r;
1200        unsigned long hret;
1201        struct hv_perf_caps caps;
1202
1203        if (!firmware_has_feature(FW_FEATURE_LPAR)) {
1204                pr_debug("not a virtualized system, not enabling\n");
1205                return -ENODEV;
1206        }
1207
1208        hret = hv_perf_caps_get(&caps);
1209        if (hret) {
1210                pr_debug("could not obtain capabilities, not enabling, rc=%ld\n",
1211                                hret);
1212                return -ENODEV;
1213        }
1214
1215        hv_page_cache = kmem_cache_create("hv-page-4096", 4096, 4096, 0, NULL);
1216        if (!hv_page_cache)
1217                return -ENOMEM;
1218
1219        /* sampling not supported */
1220        h_24x7_pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;
1221
1222        create_events_from_catalog(&event_group.attrs,
1223                                   &event_desc_group.attrs,
1224                                   &event_long_desc_group.attrs);
1225
1226        r = perf_pmu_register(&h_24x7_pmu, h_24x7_pmu.name, -1);
1227        if (r)
1228                return r;
1229
1230        return 0;
1231}
1232
1233device_initcall(hv_24x7_init);
1234