arch/powerpc/perf/hv-24x7.c

   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
  30 static 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
  44 static 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
  58 static 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
  71 static 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 */
 101 EVENT_DEFINE_RANGE_FORMAT(domain, config, 0, 3);
 102 /* u16 */
 103 EVENT_DEFINE_RANGE_FORMAT(core, config, 16, 31);
 104 EVENT_DEFINE_RANGE_FORMAT(vcpu, config, 16, 31);
 105 /* u32, see "data_offset" */
 106 EVENT_DEFINE_RANGE_FORMAT(offset, config, 32, 63);
 107 /* u16 */
 108 EVENT_DEFINE_RANGE_FORMAT(lpar, config1, 0, 15);
 109
 110 EVENT_DEFINE_RANGE(reserved1, config,   4, 15);
 111 EVENT_DEFINE_RANGE(reserved2, config1, 16, 63);
 112 EVENT_DEFINE_RANGE(reserved3, config2,  0, 63);
 113
 114 static 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
 123 static struct attribute_group format_group = {
 124         .name = "format",
 125         .attrs = format_attrs,
 126 };
 127
 128 static struct attribute_group event_group = {
 129         .name = "events",
 130         /* .attrs is set in init */
 131 };
 132
 133 static struct attribute_group event_desc_group = {
 134         .name = "event_descs",
 135         /* .attrs is set in init */
 136 };
 137
 138 static struct attribute_group event_long_desc_group = {
 139         .name = "event_long_descs",
 140         /* .attrs is set in init */
 141 };
 142
 143 static struct kmem_cache *hv_page_cache;
 144
 145 static 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
 151 static 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
 159 static 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
 169 static 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  */
 185 static 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
 237 static 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
 252 static 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
 259 static 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
 269 static 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 */
 292 static 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
 297 static 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
 306 static 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
 320 static 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;
 344 out_n:
 345         kfree(n);
 346 out_s:
 347         kfree(s);
 348         return NULL;
 349 }
 350
 351 static 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
 361 static 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;
 399 out_name:
 400         kfree(a_ev_name);
 401 out_val:
 402         kfree(val);
 403         return NULL;
 404 }
 405
 406 static 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
 420 static struct attribute *
 421 event_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
 434 static 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
 463 static 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
 475 static 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 /* */
 484 struct event_uniq {
 485         struct rb_node node;
 486         const char *name;
 487         int nl;
 488         unsigned ct;
 489         unsigned domain;
 490 };
 491
 492 static 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
 502 static 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
 516 static 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
 563 static 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  */
 583 static 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
 640 static 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
 848 e_event_descs:
 849         kfree(event_descs);
 850 e_event_attrs:
 851         kfree(events);
 852 e_event_data:
 853         vfree(event_data);
 854 e_free:
 855         kmem_cache_free(hv_page_cache, page);
 856 e_out:
 857         *events_ = NULL;
 858         *event_descs_ = NULL;
 859         *event_long_descs_ = NULL;
 860 }
 861
 862 static 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
 910 e_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)                         \
 925 static 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);                        \
 941 e_free:                                                         \
 942         kmem_cache_free(hv_page_cache, page);                   \
 943         return ret;                                             \
 944 }                                                               \
 945 static DEVICE_ATTR_RO(_name)
 946
 947 PAGE_0_ATTR(catalog_version, "%lld\n",
 948                 (unsigned long long)be64_to_cpu(page_0->version));
 949 PAGE_0_ATTR(catalog_len, "%lld\n",
 950                 (unsigned long long)be32_to_cpu(page_0->length) * 4096);
 951 static BIN_ATTR_RO(catalog, 0/* real length varies */);
 952
 953 static struct bin_attribute *if_bin_attrs[] = {
 954         &bin_attr_catalog,
 955         NULL,
 956 };
 957
 958 static struct attribute *if_attrs[] = {
 959         &dev_attr_catalog_len.attr,
 960         &dev_attr_catalog_version.attr,
 961         NULL,
 962 };
 963
 964 static struct attribute_group if_group = {
 965         .name = "interface",
 966         .bin_attrs = if_bin_attrs,
 967         .attrs = if_attrs,
 968 };
 969
 970 static 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
 979 DEFINE_PER_CPU(char, hv_24x7_reqb[4096]) __aligned(4096);
 980 DEFINE_PER_CPU(char, hv_24x7_resb[4096]) __aligned(4096);
 981
 982 static 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
1046 out:
1047         return ret;
1048 }
1049
1050 static 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
1069 static 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
1144 static 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
1156 static 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
1165 static 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
1171 static void h_24x7_event_stop(struct perf_event *event, int flags)
1172 {
1173         h_24x7_event_update(event);
1174 }
1175
1176 static 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
1184 static 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
1197 static 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
1233 device_initcall(hv_24x7_init);