kernel/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 /*
 146  * request_buffer and result_buffer are not required to be 4k aligned,
 147  * but are not allowed to cross any 4k boundary. Aligning them to 4k is
 148  * the simplest way to ensure that.
 149  */
 150 #define H24x7_DATA_BUFFER_SIZE  4096
 151 DEFINE_PER_CPU(char, hv_24x7_reqb[H24x7_DATA_BUFFER_SIZE]) __aligned(4096);
 152 DEFINE_PER_CPU(char, hv_24x7_resb[H24x7_DATA_BUFFER_SIZE]) __aligned(4096);
 153
 154 static char *event_name(struct hv_24x7_event_data *ev, int *len)
 155 {
 156         *len = be16_to_cpu(ev->event_name_len) - 2;
 157         return (char *)ev->remainder;
 158 }
 159
 160 static char *event_desc(struct hv_24x7_event_data *ev, int *len)
 161 {
 162         unsigned nl = be16_to_cpu(ev->event_name_len);
 163         __be16 *desc_len = (__be16 *)(ev->remainder + nl - 2);
 164
 165         *len = be16_to_cpu(*desc_len) - 2;
 166         return (char *)ev->remainder + nl;
 167 }
 168
 169 static char *event_long_desc(struct hv_24x7_event_data *ev, int *len)
 170 {
 171         unsigned nl = be16_to_cpu(ev->event_name_len);
 172         __be16 *desc_len_ = (__be16 *)(ev->remainder + nl - 2);
 173         unsigned desc_len = be16_to_cpu(*desc_len_);
 174         __be16 *long_desc_len = (__be16 *)(ev->remainder + nl + desc_len - 2);
 175
 176         *len = be16_to_cpu(*long_desc_len) - 2;
 177         return (char *)ev->remainder + nl + desc_len;
 178 }
 179
 180 static bool event_fixed_portion_is_within(struct hv_24x7_event_data *ev,
 181                                           void *end)
 182 {
 183         void *start = ev;
 184
 185         return (start + offsetof(struct hv_24x7_event_data, remainder)) < end;
 186 }
 187
 188 /*
 189  * Things we don't check:
 190  *  - padding for desc, name, and long/detailed desc is required to be '\0'
 191  *    bytes.
 192  *
 193  *  Return NULL if we pass end,
 194  *  Otherwise return the address of the byte just following the event.
 195  */
 196 static void *event_end(struct hv_24x7_event_data *ev, void *end)
 197 {
 198         void *start = ev;
 199         __be16 *dl_, *ldl_;
 200         unsigned dl, ldl;
 201         unsigned nl = be16_to_cpu(ev->event_name_len);
 202
 203         if (nl < 2) {
 204                 pr_debug("%s: name length too short: %d", __func__, nl);
 205                 return NULL;
 206         }
 207
 208         if (start + nl > end) {
 209                 pr_debug("%s: start=%p + nl=%u > end=%p",
 210                                 __func__, start, nl, end);
 211                 return NULL;
 212         }
 213
 214         dl_ = (__be16 *)(ev->remainder + nl - 2);
 215         if (!IS_ALIGNED((uintptr_t)dl_, 2))
 216                 pr_warn("desc len not aligned %p", dl_);
 217         dl = be16_to_cpu(*dl_);
 218         if (dl < 2) {
 219                 pr_debug("%s: desc len too short: %d", __func__, dl);
 220                 return NULL;
 221         }
 222
 223         if (start + nl + dl > end) {
 224                 pr_debug("%s: (start=%p + nl=%u + dl=%u)=%p > end=%p",
 225                                 __func__, start, nl, dl, start + nl + dl, end);
 226                 return NULL;
 227         }
 228
 229         ldl_ = (__be16 *)(ev->remainder + nl + dl - 2);
 230         if (!IS_ALIGNED((uintptr_t)ldl_, 2))
 231                 pr_warn("long desc len not aligned %p", ldl_);
 232         ldl = be16_to_cpu(*ldl_);
 233         if (ldl < 2) {
 234                 pr_debug("%s: long desc len too short (ldl=%u)",
 235                                 __func__, ldl);
 236                 return NULL;
 237         }
 238
 239         if (start + nl + dl + ldl > end) {
 240                 pr_debug("%s: start=%p + nl=%u + dl=%u + ldl=%u > end=%p",
 241                                 __func__, start, nl, dl, ldl, end);
 242                 return NULL;
 243         }
 244
 245         return start + nl + dl + ldl;
 246 }
 247
 248 static unsigned long h_get_24x7_catalog_page_(unsigned long phys_4096,
 249                                               unsigned long version,
 250                                               unsigned long index)
 251 {
 252         pr_devel("h_get_24x7_catalog_page(0x%lx, %lu, %lu)",
 253                         phys_4096, version, index);
 254
 255         WARN_ON(!IS_ALIGNED(phys_4096, 4096));
 256
 257         return plpar_hcall_norets(H_GET_24X7_CATALOG_PAGE,
 258                         phys_4096, version, index);
 259 }
 260
 261 static unsigned long h_get_24x7_catalog_page(char page[],
 262                                              u64 version, u32 index)
 263 {
 264         return h_get_24x7_catalog_page_(virt_to_phys(page),
 265                                         version, index);
 266 }
 267
 268 static unsigned core_domains[] = {
 269         HV_PERF_DOMAIN_PHYS_CORE,
 270         HV_PERF_DOMAIN_VCPU_HOME_CORE,
 271         HV_PERF_DOMAIN_VCPU_HOME_CHIP,
 272         HV_PERF_DOMAIN_VCPU_HOME_NODE,
 273         HV_PERF_DOMAIN_VCPU_REMOTE_NODE,
 274 };
 275 /* chip event data always yeilds a single event, core yeilds multiple */
 276 #define MAX_EVENTS_PER_EVENT_DATA ARRAY_SIZE(core_domains)
 277
 278 static char *event_fmt(struct hv_24x7_event_data *event, unsigned domain)
 279 {
 280         const char *sindex;
 281         const char *lpar;
 282
 283         if (is_physical_domain(domain)) {
 284                 lpar = "0x0";
 285                 sindex = "core";
 286         } else {
 287                 lpar = "?";
 288                 sindex = "vcpu";
 289         }
 290
 291         return kasprintf(GFP_KERNEL,
 292                         "domain=0x%x,offset=0x%x,%s=?,lpar=%s",
 293                         domain,
 294                         be16_to_cpu(event->event_counter_offs) +
 295                                 be16_to_cpu(event->event_group_record_offs),
 296                         sindex,
 297                         lpar);
 298 }
 299
 300 /* Avoid trusting fw to NUL terminate strings */
 301 static char *memdup_to_str(char *maybe_str, int max_len, gfp_t gfp)
 302 {
 303         return kasprintf(gfp, "%.*s", max_len, maybe_str);
 304 }
 305
 306 static ssize_t device_show_string(struct device *dev,
 307                 struct device_attribute *attr, char *buf)
 308 {
 309         struct dev_ext_attribute *d;
 310
 311         d = container_of(attr, struct dev_ext_attribute, attr);
 312
 313         return sprintf(buf, "%s\n", (char *)d->var);
 314 }
 315
 316 static struct attribute *device_str_attr_create_(char *name, char *str)
 317 {
 318         struct dev_ext_attribute *attr = kzalloc(sizeof(*attr), GFP_KERNEL);
 319
 320         if (!attr)
 321                 return NULL;
 322
 323         attr->var = str;
 324         attr->attr.attr.name = name;
 325         attr->attr.attr.mode = 0444;
 326         attr->attr.show = device_show_string;
 327
 328         return &attr->attr.attr;
 329 }
 330
 331 static struct attribute *device_str_attr_create(char *name, int name_max,
 332                                                 int name_nonce,
 333                                                 char *str, size_t str_max)
 334 {
 335         char *n;
 336         char *s = memdup_to_str(str, str_max, GFP_KERNEL);
 337         struct attribute *a;
 338
 339         if (!s)
 340                 return NULL;
 341
 342         if (!name_nonce)
 343                 n = kasprintf(GFP_KERNEL, "%.*s", name_max, name);
 344         else
 345                 n = kasprintf(GFP_KERNEL, "%.*s__%d", name_max, name,
 346                                         name_nonce);
 347         if (!n)
 348                 goto out_s;
 349
 350         a = device_str_attr_create_(n, s);
 351         if (!a)
 352                 goto out_n;
 353
 354         return a;
 355 out_n:
 356         kfree(n);
 357 out_s:
 358         kfree(s);
 359         return NULL;
 360 }
 361
 362 static void device_str_attr_destroy(struct attribute *attr)
 363 {
 364         struct dev_ext_attribute *d;
 365
 366         d = container_of(attr, struct dev_ext_attribute, attr.attr);
 367         kfree(d->var);
 368         kfree(d->attr.attr.name);
 369         kfree(d);
 370 }
 371
 372 static struct attribute *event_to_attr(unsigned ix,
 373                                        struct hv_24x7_event_data *event,
 374                                        unsigned domain,
 375                                        int nonce)
 376 {
 377         int event_name_len;
 378         char *ev_name, *a_ev_name, *val;
 379         const char *ev_suffix;
 380         struct attribute *attr;
 381
 382         if (!domain_is_valid(domain)) {
 383                 pr_warn("catalog event %u has invalid domain %u\n",
 384                                 ix, domain);
 385                 return NULL;
 386         }
 387
 388         val = event_fmt(event, domain);
 389         if (!val)
 390                 return NULL;
 391
 392         ev_suffix = event_domain_suffix(domain);
 393         ev_name = event_name(event, &event_name_len);
 394         if (!nonce)
 395                 a_ev_name = kasprintf(GFP_KERNEL, "%.*s%s",
 396                                 (int)event_name_len, ev_name, ev_suffix);
 397         else
 398                 a_ev_name = kasprintf(GFP_KERNEL, "%.*s%s__%d",
 399                                 (int)event_name_len, ev_name, ev_suffix, nonce);
 400
 401         if (!a_ev_name)
 402                 goto out_val;
 403
 404         attr = device_str_attr_create_(a_ev_name, val);
 405         if (!attr)
 406                 goto out_name;
 407
 408         return attr;
 409 out_name:
 410         kfree(a_ev_name);
 411 out_val:
 412         kfree(val);
 413         return NULL;
 414 }
 415
 416 static struct attribute *event_to_desc_attr(struct hv_24x7_event_data *event,
 417                                 int nonce)
 418 {
 419         int nl, dl;
 420         char *name = event_name(event, &nl);
 421         char *desc = event_desc(event, &dl);
 422
 423         /* If there isn't a description, don't create the sysfs file */
 424         if (!dl)
 425                 return NULL;
 426
 427         return device_str_attr_create(name, nl, nonce, desc, dl);
 428 }
 429
 430 static struct attribute *
 431 event_to_long_desc_attr(struct hv_24x7_event_data *event, int nonce)
 432 {
 433         int nl, dl;
 434         char *name = event_name(event, &nl);
 435         char *desc = event_long_desc(event, &dl);
 436
 437         /* If there isn't a description, don't create the sysfs file */
 438         if (!dl)
 439                 return NULL;
 440
 441         return device_str_attr_create(name, nl, nonce, desc, dl);
 442 }
 443
 444 static ssize_t event_data_to_attrs(unsigned ix, struct attribute **attrs,
 445                 struct hv_24x7_event_data *event, int nonce)
 446 {
 447         unsigned i;
 448
 449         switch (event->domain) {
 450         case HV_PERF_DOMAIN_PHYS_CHIP:
 451                 *attrs = event_to_attr(ix, event, event->domain, nonce);
 452                 return 1;
 453         case HV_PERF_DOMAIN_PHYS_CORE:
 454                 for (i = 0; i < ARRAY_SIZE(core_domains); i++) {
 455                         attrs[i] = event_to_attr(ix, event, core_domains[i],
 456                                                 nonce);
 457                         if (!attrs[i]) {
 458                                 pr_warn("catalog event %u: individual attr %u "
 459                                         "creation failure\n", ix, i);
 460                                 for (; i; i--)
 461                                         device_str_attr_destroy(attrs[i - 1]);
 462                                 return -1;
 463                         }
 464                 }
 465                 return i;
 466         default:
 467                 pr_warn("catalog event %u: domain %u is not allowed in the "
 468                                 "catalog\n", ix, event->domain);
 469                 return -1;
 470         }
 471 }
 472
 473 static size_t event_to_attr_ct(struct hv_24x7_event_data *event)
 474 {
 475         switch (event->domain) {
 476         case HV_PERF_DOMAIN_PHYS_CHIP:
 477                 return 1;
 478         case HV_PERF_DOMAIN_PHYS_CORE:
 479                 return ARRAY_SIZE(core_domains);
 480         default:
 481                 return 0;
 482         }
 483 }
 484
 485 static unsigned long vmalloc_to_phys(void *v)
 486 {
 487         struct page *p = vmalloc_to_page(v);
 488
 489         BUG_ON(!p);
 490         return page_to_phys(p) + offset_in_page(v);
 491 }
 492
 493 /* */
 494 struct event_uniq {
 495         struct rb_node node;
 496         const char *name;
 497         int nl;
 498         unsigned ct;
 499         unsigned domain;
 500 };
 501
 502 static int memord(const void *d1, size_t s1, const void *d2, size_t s2)
 503 {
 504         if (s1 < s2)
 505                 return 1;
 506         if (s2 > s1)
 507                 return -1;
 508
 509         return memcmp(d1, d2, s1);
 510 }
 511
 512 static int ev_uniq_ord(const void *v1, size_t s1, unsigned d1, const void *v2,
 513                                         size_t s2, unsigned d2)
 514 {
 515         int r = memord(v1, s1, v2, s2);
 516
 517         if (r)
 518                 return r;
 519         if (d1 > d2)
 520                 return 1;
 521         if (d2 > d1)
 522                 return -1;
 523         return 0;
 524 }
 525
 526 static int event_uniq_add(struct rb_root *root, const char *name, int nl,
 527                                 unsigned domain)
 528 {
 529         struct rb_node **new = &(root->rb_node), *parent = NULL;
 530         struct event_uniq *data;
 531
 532         /* Figure out where to put new node */
 533         while (*new) {
 534                 struct event_uniq *it;
 535                 int result;
 536
 537                 it = container_of(*new, struct event_uniq, node);
 538                 result = ev_uniq_ord(name, nl, domain, it->name, it->nl,
 539                                         it->domain);
 540
 541                 parent = *new;
 542                 if (result < 0)
 543                         new = &((*new)->rb_left);
 544                 else if (result > 0)
 545                         new = &((*new)->rb_right);
 546                 else {
 547                         it->ct++;
 548                         pr_info("found a duplicate event %.*s, ct=%u\n", nl,
 549                                                 name, it->ct);
 550                         return it->ct;
 551                 }
 552         }
 553
 554         data = kmalloc(sizeof(*data), GFP_KERNEL);
 555         if (!data)
 556                 return -ENOMEM;
 557
 558         *data = (struct event_uniq) {
 559                 .name = name,
 560                 .nl = nl,
 561                 .ct = 0,
 562                 .domain = domain,
 563         };
 564
 565         /* Add new node and rebalance tree. */
 566         rb_link_node(&data->node, parent, new);
 567         rb_insert_color(&data->node, root);
 568
 569         /* data->ct */
 570         return 0;
 571 }
 572
 573 static void event_uniq_destroy(struct rb_root *root)
 574 {
 575         /*
 576          * the strings we point to are in the giant block of memory filled by
 577          * the catalog, and are freed separately.
 578          */
 579         struct event_uniq *pos, *n;
 580
 581         rbtree_postorder_for_each_entry_safe(pos, n, root, node)
 582                 kfree(pos);
 583 }
 584
 585
 586 /*
 587  * ensure the event structure's sizes are self consistent and don't cause us to
 588  * read outside of the event
 589  *
 590  * On success, return the event length in bytes.
 591  * Otherwise, return -1 (and print as appropriate).
 592  */
 593 static ssize_t catalog_event_len_validate(struct hv_24x7_event_data *event,
 594                                           size_t event_idx,
 595                                           size_t event_data_bytes,
 596                                           size_t event_entry_count,
 597                                           size_t offset, void *end)
 598 {
 599         ssize_t ev_len;
 600         void *ev_end, *calc_ev_end;
 601
 602         if (offset >= event_data_bytes)
 603                 return -1;
 604
 605         if (event_idx >= event_entry_count) {
 606                 pr_devel("catalog event data has %zu bytes of padding after last event\n",
 607                                 event_data_bytes - offset);
 608                 return -1;
 609         }
 610
 611         if (!event_fixed_portion_is_within(event, end)) {
 612                 pr_warn("event %zu fixed portion is not within range\n",
 613                                 event_idx);
 614                 return -1;
 615         }
 616
 617         ev_len = be16_to_cpu(event->length);
 618
 619         if (ev_len % 16)
 620                 pr_info("event %zu has length %zu not divisible by 16: event=%pK\n",
 621                                 event_idx, ev_len, event);
 622
 623         ev_end = (__u8 *)event + ev_len;
 624         if (ev_end > end) {
 625                 pr_warn("event %zu has .length=%zu, ends after buffer end: ev_end=%pK > end=%pK, offset=%zu\n",
 626                                 event_idx, ev_len, ev_end, end,
 627                                 offset);
 628                 return -1;
 629         }
 630
 631         calc_ev_end = event_end(event, end);
 632         if (!calc_ev_end) {
 633                 pr_warn("event %zu has a calculated length which exceeds buffer length %zu: event=%pK end=%pK, offset=%zu\n",
 634                         event_idx, event_data_bytes, event, end,
 635                         offset);
 636                 return -1;
 637         }
 638
 639         if (calc_ev_end > ev_end) {
 640                 pr_warn("event %zu exceeds it's own length: event=%pK, end=%pK, offset=%zu, calc_ev_end=%pK\n",
 641                         event_idx, event, ev_end, offset, calc_ev_end);
 642                 return -1;
 643         }
 644
 645         return ev_len;
 646 }
 647
 648 #define MAX_4K (SIZE_MAX / 4096)
 649
 650 static int create_events_from_catalog(struct attribute ***events_,
 651                 struct attribute ***event_descs_,
 652                 struct attribute ***event_long_descs_)
 653 {
 654         unsigned long hret;
 655         size_t catalog_len, catalog_page_len, event_entry_count,
 656                event_data_len, event_data_offs,
 657                event_data_bytes, junk_events, event_idx, event_attr_ct, i,
 658                attr_max, event_idx_last, desc_ct, long_desc_ct;
 659         ssize_t ct, ev_len;
 660         uint32_t catalog_version_num;
 661         struct attribute **events, **event_descs, **event_long_descs;
 662         struct hv_24x7_catalog_page_0 *page_0 =
 663                 kmem_cache_alloc(hv_page_cache, GFP_KERNEL);
 664         void *page = page_0;
 665         void *event_data, *end;
 666         struct hv_24x7_event_data *event;
 667         struct rb_root ev_uniq = RB_ROOT;
 668         int ret = 0;
 669
 670         if (!page) {
 671                 ret = -ENOMEM;
 672                 goto e_out;
 673         }
 674
 675         hret = h_get_24x7_catalog_page(page, 0, 0);
 676         if (hret) {
 677                 ret = -EIO;
 678                 goto e_free;
 679         }
 680
 681         catalog_version_num = be64_to_cpu(page_0->version);
 682         catalog_page_len = be32_to_cpu(page_0->length);
 683
 684         if (MAX_4K < catalog_page_len) {
 685                 pr_err("invalid page count: %zu\n", catalog_page_len);
 686                 ret = -EIO;
 687                 goto e_free;
 688         }
 689
 690         catalog_len = catalog_page_len * 4096;
 691
 692         event_entry_count = be16_to_cpu(page_0->event_entry_count);
 693         event_data_offs   = be16_to_cpu(page_0->event_data_offs);
 694         event_data_len    = be16_to_cpu(page_0->event_data_len);
 695
 696         pr_devel("cv %zu cl %zu eec %zu edo %zu edl %zu\n",
 697                         (size_t)catalog_version_num, catalog_len,
 698                         event_entry_count, event_data_offs, event_data_len);
 699
 700         if ((MAX_4K < event_data_len)
 701                         || (MAX_4K < event_data_offs)
 702                         || (MAX_4K - event_data_offs < event_data_len)) {
 703                 pr_err("invalid event data offs %zu and/or len %zu\n",
 704                                 event_data_offs, event_data_len);
 705                 ret = -EIO;
 706                 goto e_free;
 707         }
 708
 709         if ((event_data_offs + event_data_len) > catalog_page_len) {
 710                 pr_err("event data %zu-%zu does not fit inside catalog 0-%zu\n",
 711                                 event_data_offs,
 712                                 event_data_offs + event_data_len,
 713                                 catalog_page_len);
 714                 ret = -EIO;
 715                 goto e_free;
 716         }
 717
 718         if (SIZE_MAX / MAX_EVENTS_PER_EVENT_DATA - 1 < event_entry_count) {
 719                 pr_err("event_entry_count %zu is invalid\n",
 720                                 event_entry_count);
 721                 ret = -EIO;
 722                 goto e_free;
 723         }
 724
 725         event_data_bytes = event_data_len * 4096;
 726
 727         /*
 728          * event data can span several pages, events can cross between these
 729          * pages. Use vmalloc to make this easier.
 730          */
 731         event_data = vmalloc(event_data_bytes);
 732         if (!event_data) {
 733                 pr_err("could not allocate event data\n");
 734                 ret = -ENOMEM;
 735                 goto e_free;
 736         }
 737
 738         end = event_data + event_data_bytes;
 739
 740         /*
 741          * using vmalloc_to_phys() like this only works if PAGE_SIZE is
 742          * divisible by 4096
 743          */
 744         BUILD_BUG_ON(PAGE_SIZE % 4096);
 745
 746         for (i = 0; i < event_data_len; i++) {
 747                 hret = h_get_24x7_catalog_page_(
 748                                 vmalloc_to_phys(event_data + i * 4096),
 749                                 catalog_version_num,
 750                                 i + event_data_offs);
 751                 if (hret) {
 752                         pr_err("failed to get event data in page %zu\n",
 753                                         i + event_data_offs);
 754                         ret = -EIO;
 755                         goto e_event_data;
 756                 }
 757         }
 758
 759         /*
 760          * scan the catalog to determine the number of attributes we need, and
 761          * verify it at the same time.
 762          */
 763         for (junk_events = 0, event = event_data, event_idx = 0, attr_max = 0;
 764              ;
 765              event_idx++, event = (void *)event + ev_len) {
 766                 size_t offset = (void *)event - (void *)event_data;
 767                 char *name;
 768                 int nl;
 769
 770                 ev_len = catalog_event_len_validate(event, event_idx,
 771                                                     event_data_bytes,
 772                                                     event_entry_count,
 773                                                     offset, end);
 774                 if (ev_len < 0)
 775                         break;
 776
 777                 name = event_name(event, &nl);
 778
 779                 if (event->event_group_record_len == 0) {
 780                         pr_devel("invalid event %zu (%.*s): group_record_len == 0, skipping\n",
 781                                         event_idx, nl, name);
 782                         junk_events++;
 783                         continue;
 784                 }
 785
 786                 if (!catalog_entry_domain_is_valid(event->domain)) {
 787                         pr_info("event %zu (%.*s) has invalid domain %d\n",
 788                                         event_idx, nl, name, event->domain);
 789                         junk_events++;
 790                         continue;
 791                 }
 792
 793                 attr_max += event_to_attr_ct(event);
 794         }
 795
 796         event_idx_last = event_idx;
 797         if (event_idx_last != event_entry_count)
 798                 pr_warn("event buffer ended before listed # of events were parsed (got %zu, wanted %zu, junk %zu)\n",
 799                                 event_idx_last, event_entry_count, junk_events);
 800
 801         events = kmalloc_array(attr_max + 1, sizeof(*events), GFP_KERNEL);
 802         if (!events) {
 803                 ret = -ENOMEM;
 804                 goto e_event_data;
 805         }
 806
 807         event_descs = kmalloc_array(event_idx + 1, sizeof(*event_descs),
 808                                 GFP_KERNEL);
 809         if (!event_descs) {
 810                 ret = -ENOMEM;
 811                 goto e_event_attrs;
 812         }
 813
 814         event_long_descs = kmalloc_array(event_idx + 1,
 815                         sizeof(*event_long_descs), GFP_KERNEL);
 816         if (!event_long_descs) {
 817                 ret = -ENOMEM;
 818                 goto e_event_descs;
 819         }
 820
 821         /* Iterate over the catalog filling in the attribute vector */
 822         for (junk_events = 0, event_attr_ct = 0, desc_ct = 0, long_desc_ct = 0,
 823                                 event = event_data, event_idx = 0;
 824                         event_idx < event_idx_last;
 825                         event_idx++, ev_len = be16_to_cpu(event->length),
 826                                 event = (void *)event + ev_len) {
 827                 char *name;
 828                 int nl;
 829                 int nonce;
 830                 /*
 831                  * these are the only "bad" events that are intermixed and that
 832                  * we can ignore without issue. make sure to skip them here
 833                  */
 834                 if (event->event_group_record_len == 0)
 835                         continue;
 836                 if (!catalog_entry_domain_is_valid(event->domain))
 837                         continue;
 838
 839                 name  = event_name(event, &nl);
 840                 nonce = event_uniq_add(&ev_uniq, name, nl, event->domain);
 841                 ct    = event_data_to_attrs(event_idx, events + event_attr_ct,
 842                                             event, nonce);
 843                 if (ct <= 0) {
 844                         pr_warn("event %zu (%.*s) creation failure, skipping\n",
 845                                 event_idx, nl, name);
 846                         junk_events++;
 847                 } else {
 848                         event_attr_ct += ct;
 849                         event_descs[desc_ct] = event_to_desc_attr(event, nonce);
 850                         if (event_descs[desc_ct])
 851                                 desc_ct++;
 852                         event_long_descs[long_desc_ct] =
 853                                         event_to_long_desc_attr(event, nonce);
 854                         if (event_long_descs[long_desc_ct])
 855                                 long_desc_ct++;
 856                 }
 857         }
 858
 859         pr_info("read %zu catalog entries, created %zu event attrs (%zu failures), %zu descs\n",
 860                         event_idx, event_attr_ct, junk_events, desc_ct);
 861
 862         events[event_attr_ct] = NULL;
 863         event_descs[desc_ct] = NULL;
 864         event_long_descs[long_desc_ct] = NULL;
 865
 866         event_uniq_destroy(&ev_uniq);
 867         vfree(event_data);
 868         kmem_cache_free(hv_page_cache, page);
 869
 870         *events_ = events;
 871         *event_descs_ = event_descs;
 872         *event_long_descs_ = event_long_descs;
 873         return 0;
 874
 875 e_event_descs:
 876         kfree(event_descs);
 877 e_event_attrs:
 878         kfree(events);
 879 e_event_data:
 880         vfree(event_data);
 881 e_free:
 882         kmem_cache_free(hv_page_cache, page);
 883 e_out:
 884         *events_ = NULL;
 885         *event_descs_ = NULL;
 886         *event_long_descs_ = NULL;
 887         return ret;
 888 }
 889
 890 static ssize_t catalog_read(struct file *filp, struct kobject *kobj,
 891                             struct bin_attribute *bin_attr, char *buf,
 892                             loff_t offset, size_t count)
 893 {
 894         unsigned long hret;
 895         ssize_t ret = 0;
 896         size_t catalog_len = 0, catalog_page_len = 0;
 897         loff_t page_offset = 0;
 898         loff_t offset_in_page;
 899         size_t copy_len;
 900         uint64_t catalog_version_num = 0;
 901         void *page = kmem_cache_alloc(hv_page_cache, GFP_USER);
 902         struct hv_24x7_catalog_page_0 *page_0 = page;
 903
 904         if (!page)
 905                 return -ENOMEM;
 906
 907         hret = h_get_24x7_catalog_page(page, 0, 0);
 908         if (hret) {
 909                 ret = -EIO;
 910                 goto e_free;
 911         }
 912
 913         catalog_version_num = be64_to_cpu(page_0->version);
 914         catalog_page_len = be32_to_cpu(page_0->length);
 915         catalog_len = catalog_page_len * 4096;
 916
 917         page_offset = offset / 4096;
 918         offset_in_page = offset % 4096;
 919
 920         if (page_offset >= catalog_page_len)
 921                 goto e_free;
 922
 923         if (page_offset != 0) {
 924                 hret = h_get_24x7_catalog_page(page, catalog_version_num,
 925                                                page_offset);
 926                 if (hret) {
 927                         ret = -EIO;
 928                         goto e_free;
 929                 }
 930         }
 931
 932         copy_len = 4096 - offset_in_page;
 933         if (copy_len > count)
 934                 copy_len = count;
 935
 936         memcpy(buf, page+offset_in_page, copy_len);
 937         ret = copy_len;
 938
 939 e_free:
 940         if (hret)
 941                 pr_err("h_get_24x7_catalog_page(ver=%lld, page=%lld) failed:"
 942                        " rc=%ld\n",
 943                        catalog_version_num, page_offset, hret);
 944         kmem_cache_free(hv_page_cache, page);
 945
 946         pr_devel("catalog_read: offset=%lld(%lld) count=%zu "
 947                         "catalog_len=%zu(%zu) => %zd\n", offset, page_offset,
 948                         count, catalog_len, catalog_page_len, ret);
 949
 950         return ret;
 951 }
 952
 953 #define PAGE_0_ATTR(_name, _fmt, _expr)                         \
 954 static ssize_t _name##_show(struct device *dev,                 \
 955                             struct device_attribute *dev_attr,  \
 956                             char *buf)                          \
 957 {                                                               \
 958         unsigned long hret;                                     \
 959         ssize_t ret = 0;                                        \
 960         void *page = kmem_cache_alloc(hv_page_cache, GFP_USER); \
 961         struct hv_24x7_catalog_page_0 *page_0 = page;           \
 962         if (!page)                                              \
 963                 return -ENOMEM;                                 \
 964         hret = h_get_24x7_catalog_page(page, 0, 0);             \
 965         if (hret) {                                             \
 966                 ret = -EIO;                                     \
 967                 goto e_free;                                    \
 968         }                                                       \
 969         ret = sprintf(buf, _fmt, _expr);                        \
 970 e_free:                                                         \
 971         kmem_cache_free(hv_page_cache, page);                   \
 972         return ret;                                             \
 973 }                                                               \
 974 static DEVICE_ATTR_RO(_name)
 975
 976 PAGE_0_ATTR(catalog_version, "%lld\n",
 977                 (unsigned long long)be64_to_cpu(page_0->version));
 978 PAGE_0_ATTR(catalog_len, "%lld\n",
 979                 (unsigned long long)be32_to_cpu(page_0->length) * 4096);
 980 static BIN_ATTR_RO(catalog, 0/* real length varies */);
 981
 982 static struct bin_attribute *if_bin_attrs[] = {
 983         &bin_attr_catalog,
 984         NULL,
 985 };
 986
 987 static struct attribute *if_attrs[] = {
 988         &dev_attr_catalog_len.attr,
 989         &dev_attr_catalog_version.attr,
 990         NULL,
 991 };
 992
 993 static struct attribute_group if_group = {
 994         .name = "interface",
 995         .bin_attrs = if_bin_attrs,
 996         .attrs = if_attrs,
 997 };
 998
 999 static const struct attribute_group *attr_groups[] = {
1000         &format_group,
1001         &event_group,
1002         &event_desc_group,
1003         &event_long_desc_group,
1004         &if_group,
1005         NULL,
1006 };
1007
1008 static void log_24x7_hcall(struct hv_24x7_request_buffer *request_buffer,
1009                         struct hv_24x7_data_result_buffer *result_buffer,
1010                         unsigned long ret)
1011 {
1012         struct hv_24x7_request *req;
1013
1014         req = &request_buffer->requests[0];
1015         pr_notice_ratelimited("hcall failed: [%d %#x %#x %d] => "
1016                         "ret 0x%lx (%ld) detail=0x%x failing ix=%x\n",
1017                         req->performance_domain, req->data_offset,
1018                         req->starting_ix, req->starting_lpar_ix, ret, ret,
1019                         result_buffer->detailed_rc,
1020                         result_buffer->failing_request_ix);
1021 }
1022
1023 /*
1024  * Start the process for a new H_GET_24x7_DATA hcall.
1025  */
1026 static void init_24x7_request(struct hv_24x7_request_buffer *request_buffer,
1027                         struct hv_24x7_data_result_buffer *result_buffer)
1028 {
1029
1030         memset(request_buffer, 0, 4096);
1031         memset(result_buffer, 0, 4096);
1032
1033         request_buffer->interface_version = HV_24X7_IF_VERSION_CURRENT;
1034         /* memset above set request_buffer->num_requests to 0 */
1035 }
1036
1037 /*
1038  * Commit (i.e perform) the H_GET_24x7_DATA hcall using the data collected
1039  * by 'init_24x7_request()' and 'add_event_to_24x7_request()'.
1040  */
1041 static int make_24x7_request(struct hv_24x7_request_buffer *request_buffer,
1042                         struct hv_24x7_data_result_buffer *result_buffer)
1043 {
1044         unsigned long ret;
1045
1046         /*
1047          * NOTE: Due to variable number of array elements in request and
1048          *       result buffer(s), sizeof() is not reliable. Use the actual
1049          *       allocated buffer size, H24x7_DATA_BUFFER_SIZE.
1050          */
1051         ret = plpar_hcall_norets(H_GET_24X7_DATA,
1052                         virt_to_phys(request_buffer), H24x7_DATA_BUFFER_SIZE,
1053                         virt_to_phys(result_buffer),  H24x7_DATA_BUFFER_SIZE);
1054
1055         if (ret)
1056                 log_24x7_hcall(request_buffer, result_buffer, ret);
1057
1058         return ret;
1059 }
1060
1061 /*
1062  * Add the given @event to the next slot in the 24x7 request_buffer.
1063  *
1064  * Note that H_GET_24X7_DATA hcall allows reading several counters'
1065  * values in a single HCALL. We expect the caller to add events to the
1066  * request buffer one by one, make the HCALL and process the results.
1067  */
1068 static int add_event_to_24x7_request(struct perf_event *event,
1069                                 struct hv_24x7_request_buffer *request_buffer)
1070 {
1071         u16 idx;
1072         int i;
1073         struct hv_24x7_request *req;
1074
1075         if (request_buffer->num_requests > 254) {
1076                 pr_devel("Too many requests for 24x7 HCALL %d\n",
1077                                 request_buffer->num_requests);
1078                 return -EINVAL;
1079         }
1080
1081         if (is_physical_domain(event_get_domain(event)))
1082                 idx = event_get_core(event);
1083         else
1084                 idx = event_get_vcpu(event);
1085
1086         i = request_buffer->num_requests++;
1087         req = &request_buffer->requests[i];
1088
1089         req->performance_domain = event_get_domain(event);
1090         req->data_size = cpu_to_be16(8);
1091         req->data_offset = cpu_to_be32(event_get_offset(event));
1092         req->starting_lpar_ix = cpu_to_be16(event_get_lpar(event)),
1093         req->max_num_lpars = cpu_to_be16(1);
1094         req->starting_ix = cpu_to_be16(idx);
1095         req->max_ix = cpu_to_be16(1);
1096
1097         return 0;
1098 }
1099
1100 static unsigned long single_24x7_request(struct perf_event *event, u64 *count)
1101 {
1102         unsigned long ret;
1103         struct hv_24x7_request_buffer *request_buffer;
1104         struct hv_24x7_data_result_buffer *result_buffer;
1105         struct hv_24x7_result *resb;
1106
1107         BUILD_BUG_ON(sizeof(*request_buffer) > 4096);
1108         BUILD_BUG_ON(sizeof(*result_buffer) > 4096);
1109
1110         request_buffer = (void *)get_cpu_var(hv_24x7_reqb);
1111         result_buffer = (void *)get_cpu_var(hv_24x7_resb);
1112
1113         init_24x7_request(request_buffer, result_buffer);
1114
1115         ret = add_event_to_24x7_request(event, request_buffer);
1116         if (ret)
1117                 goto out;
1118
1119         ret = make_24x7_request(request_buffer, result_buffer);
1120         if (ret) {
1121                 log_24x7_hcall(request_buffer, result_buffer, ret);
1122                 goto out;
1123         }
1124
1125         /* process result from hcall */
1126         resb = &result_buffer->results[0];
1127         *count = be64_to_cpu(resb->elements[0].element_data[0]);
1128
1129 out:
1130         put_cpu_var(hv_24x7_reqb);
1131         put_cpu_var(hv_24x7_resb);
1132         return ret;
1133 }
1134
1135
1136 static int h_24x7_event_init(struct perf_event *event)
1137 {
1138         struct hv_perf_caps caps;
1139         unsigned domain;
1140         unsigned long hret;
1141         u64 ct;
1142
1143         /* Not our event */
1144         if (event->attr.type != event->pmu->type)
1145                 return -ENOENT;
1146
1147         /* Unused areas must be 0 */
1148         if (event_get_reserved1(event) ||
1149             event_get_reserved2(event) ||
1150             event_get_reserved3(event)) {
1151                 pr_devel("reserved set when forbidden 0x%llx(0x%llx) 0x%llx(0x%llx) 0x%llx(0x%llx)\n",
1152                                 event->attr.config,
1153                                 event_get_reserved1(event),
1154                                 event->attr.config1,
1155                                 event_get_reserved2(event),
1156                                 event->attr.config2,
1157                                 event_get_reserved3(event));
1158                 return -EINVAL;
1159         }
1160
1161         /* unsupported modes and filters */
1162         if (event->attr.exclude_user   ||
1163             event->attr.exclude_kernel ||
1164             event->attr.exclude_hv     ||
1165             event->attr.exclude_idle   ||
1166             event->attr.exclude_host   ||
1167             event->attr.exclude_guest)
1168                 return -EINVAL;
1169
1170         /* no branch sampling */
1171         if (has_branch_stack(event))
1172                 return -EOPNOTSUPP;
1173
1174         /* offset must be 8 byte aligned */
1175         if (event_get_offset(event) % 8) {
1176                 pr_devel("bad alignment\n");
1177                 return -EINVAL;
1178         }
1179
1180         /* Domains above 6 are invalid */
1181         domain = event_get_domain(event);
1182         if (domain > 6) {
1183                 pr_devel("invalid domain %d\n", domain);
1184                 return -EINVAL;
1185         }
1186
1187         hret = hv_perf_caps_get(&caps);
1188         if (hret) {
1189                 pr_devel("could not get capabilities: rc=%ld\n", hret);
1190                 return -EIO;
1191         }
1192
1193         /* Physical domains & other lpars require extra capabilities */
1194         if (!caps.collect_privileged && (is_physical_domain(domain) ||
1195                 (event_get_lpar(event) != event_get_lpar_max()))) {
1196                 pr_devel("hv permissions disallow: is_physical_domain:%d, lpar=0x%llx\n",
1197                                 is_physical_domain(domain),
1198                                 event_get_lpar(event));
1199                 return -EACCES;
1200         }
1201
1202         /* see if the event complains */
1203         if (single_24x7_request(event, &ct)) {
1204                 pr_devel("test hcall failed\n");
1205                 return -EIO;
1206         }
1207
1208         return 0;
1209 }
1210
1211 static u64 h_24x7_get_value(struct perf_event *event)
1212 {
1213         unsigned long ret;
1214         u64 ct;
1215         ret = single_24x7_request(event, &ct);
1216         if (ret)
1217                 /* We checked this in event init, shouldn't fail here... */
1218                 return 0;
1219
1220         return ct;
1221 }
1222
1223 static void update_event_count(struct perf_event *event, u64 now)
1224 {
1225         s64 prev;
1226
1227         prev = local64_xchg(&event->hw.prev_count, now);
1228         local64_add(now - prev, &event->count);
1229 }
1230
1231 static void h_24x7_event_read(struct perf_event *event)
1232 {
1233         u64 now;
1234
1235         now = h_24x7_get_value(event);
1236         update_event_count(event, now);
1237 }
1238
1239 static void h_24x7_event_start(struct perf_event *event, int flags)
1240 {
1241         if (flags & PERF_EF_RELOAD)
1242                 local64_set(&event->hw.prev_count, h_24x7_get_value(event));
1243 }
1244
1245 static void h_24x7_event_stop(struct perf_event *event, int flags)
1246 {
1247         h_24x7_event_read(event);
1248 }
1249
1250 static int h_24x7_event_add(struct perf_event *event, int flags)
1251 {
1252         if (flags & PERF_EF_START)
1253                 h_24x7_event_start(event, flags);
1254
1255         return 0;
1256 }
1257
1258 static struct pmu h_24x7_pmu = {
1259         .task_ctx_nr = perf_invalid_context,
1260
1261         .name = "hv_24x7",
1262         .attr_groups = attr_groups,
1263         .event_init  = h_24x7_event_init,
1264         .add         = h_24x7_event_add,
1265         .del         = h_24x7_event_stop,
1266         .start       = h_24x7_event_start,
1267         .stop        = h_24x7_event_stop,
1268         .read        = h_24x7_event_read,
1269 };
1270
1271 static int hv_24x7_init(void)
1272 {
1273         int r;
1274         unsigned long hret;
1275         struct hv_perf_caps caps;
1276
1277         if (!firmware_has_feature(FW_FEATURE_LPAR)) {
1278                 pr_debug("not a virtualized system, not enabling\n");
1279                 return -ENODEV;
1280         }
1281
1282         hret = hv_perf_caps_get(&caps);
1283         if (hret) {
1284                 pr_debug("could not obtain capabilities, not enabling, rc=%ld\n",
1285                                 hret);
1286                 return -ENODEV;
1287         }
1288
1289         hv_page_cache = kmem_cache_create("hv-page-4096", 4096, 4096, 0, NULL);
1290         if (!hv_page_cache)
1291                 return -ENOMEM;
1292
1293         /* sampling not supported */
1294         h_24x7_pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;
1295
1296         r = create_events_from_catalog(&event_group.attrs,
1297                                    &event_desc_group.attrs,
1298                                    &event_long_desc_group.attrs);
1299
1300         if (r)
1301                 return r;
1302
1303         r = perf_pmu_register(&h_24x7_pmu, h_24x7_pmu.name, -1);
1304         if (r)
1305                 return r;
1306
1307         return 0;
1308 }
1309
1310 device_initcall(hv_24x7_init);