arch/x86/kernel/cpu/resctrl/ctrlmondata.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Resource Director Technology(RDT)
   4  * - Cache Allocation code.
   5  *
   6  * Copyright (C) 2016 Intel Corporation
   7  *
   8  * Authors:
   9  *    Fenghua Yu <[email protected]>
  10  *    Tony Luck <[email protected]>
  11  *
  12  * More information about RDT be found in the Intel (R) x86 Architecture
  13  * Software Developer Manual June 2016, volume 3, section 17.17.
  14  */
  15
  16 #define pr_fmt(fmt)     KBUILD_MODNAME ": " fmt
  17
  18 #include <linux/cpu.h>
  19 #include <linux/kernfs.h>
  20 #include <linux/seq_file.h>
  21 #include <linux/slab.h>
  22 #include <linux/tick.h>
  23
  24 #include "internal.h"
  25
  26 /*
  27  * Check whether MBA bandwidth percentage value is correct. The value is
  28  * checked against the minimum and max bandwidth values specified by the
  29  * hardware. The allocated bandwidth percentage is rounded to the next
  30  * control step available on the hardware.
  31  */
  32 static bool bw_validate(char *buf, u32 *data, struct rdt_resource *r)
  33 {
  34         int ret;
  35         u32 bw;
  36
  37         /*
  38          * Only linear delay values is supported for current Intel SKUs.
  39          */
  40         if (!r->membw.delay_linear && r->membw.arch_needs_linear) {
  41                 rdt_last_cmd_puts("No support for non-linear MB domains\n");
  42                 return false;
  43         }
  44
  45         ret = kstrtou32(buf, 10, &bw);
  46         if (ret) {
  47                 rdt_last_cmd_printf("Invalid MB value %s\n", buf);
  48                 return false;
  49         }
  50
  51         /* Nothing else to do if software controller is enabled. */
  52         if (is_mba_sc(r)) {
  53                 *data = bw;
  54                 return true;
  55         }
  56
  57         if (bw < r->membw.min_bw || bw > r->default_ctrl) {
  58                 rdt_last_cmd_printf("MB value %u out of range [%d,%d]\n",
  59                                     bw, r->membw.min_bw, r->default_ctrl);
  60                 return false;
  61         }
  62
  63         *data = roundup(bw, (unsigned long)r->membw.bw_gran);
  64         return true;
  65 }
  66
  67 int parse_bw(struct rdt_parse_data *data, struct resctrl_schema *s,
  68              struct rdt_ctrl_domain *d)
  69 {
  70         struct resctrl_staged_config *cfg;
  71         u32 closid = data->rdtgrp->closid;
  72         struct rdt_resource *r = s->res;
  73         u32 bw_val;
  74
  75         cfg = &d->staged_config[s->conf_type];
  76         if (cfg->have_new_ctrl) {
  77                 rdt_last_cmd_printf("Duplicate domain %d\n", d->hdr.id);
  78                 return -EINVAL;
  79         }
  80
  81         if (!bw_validate(data->buf, &bw_val, r))
  82                 return -EINVAL;
  83
  84         if (is_mba_sc(r)) {
  85                 d->mbps_val[closid] = bw_val;
  86                 return 0;
  87         }
  88
  89         cfg->new_ctrl = bw_val;
  90         cfg->have_new_ctrl = true;
  91
  92         return 0;
  93 }
  94
  95 /*
  96  * Check whether a cache bit mask is valid.
  97  * On Intel CPUs, non-contiguous 1s value support is indicated by CPUID:
  98  *   - CPUID.0x10.1:ECX[3]: L3 non-contiguous 1s value supported if 1
  99  *   - CPUID.0x10.2:ECX[3]: L2 non-contiguous 1s value supported if 1
 100  *
 101  * Haswell does not support a non-contiguous 1s value and additionally
 102  * requires at least two bits set.
 103  * AMD allows non-contiguous bitmasks.
 104  */
 105 static bool cbm_validate(char *buf, u32 *data, struct rdt_resource *r)
 106 {
 107         unsigned long first_bit, zero_bit, val;
 108         unsigned int cbm_len = r->cache.cbm_len;
 109         int ret;
 110
 111         ret = kstrtoul(buf, 16, &val);
 112         if (ret) {
 113                 rdt_last_cmd_printf("Non-hex character in the mask %s\n", buf);
 114                 return false;
 115         }
 116
 117         if ((r->cache.min_cbm_bits > 0 && val == 0) || val > r->default_ctrl) {
 118                 rdt_last_cmd_puts("Mask out of range\n");
 119                 return false;
 120         }
 121
 122         first_bit = find_first_bit(&val, cbm_len);
 123         zero_bit = find_next_zero_bit(&val, cbm_len, first_bit);
 124
 125         /* Are non-contiguous bitmasks allowed? */
 126         if (!r->cache.arch_has_sparse_bitmasks &&
 127             (find_next_bit(&val, cbm_len, zero_bit) < cbm_len)) {
 128                 rdt_last_cmd_printf("The mask %lx has non-consecutive 1-bits\n", val);
 129                 return false;
 130         }
 131
 132         if ((zero_bit - first_bit) < r->cache.min_cbm_bits) {
 133                 rdt_last_cmd_printf("Need at least %d bits in the mask\n",
 134                                     r->cache.min_cbm_bits);
 135                 return false;
 136         }
 137
 138         *data = val;
 139         return true;
 140 }
 141
 142 /*
 143  * Read one cache bit mask (hex). Check that it is valid for the current
 144  * resource type.
 145  */
 146 int parse_cbm(struct rdt_parse_data *data, struct resctrl_schema *s,
 147               struct rdt_ctrl_domain *d)
 148 {
 149         struct rdtgroup *rdtgrp = data->rdtgrp;
 150         struct resctrl_staged_config *cfg;
 151         struct rdt_resource *r = s->res;
 152         u32 cbm_val;
 153
 154         cfg = &d->staged_config[s->conf_type];
 155         if (cfg->have_new_ctrl) {
 156                 rdt_last_cmd_printf("Duplicate domain %d\n", d->hdr.id);
 157                 return -EINVAL;
 158         }
 159
 160         /*
 161          * Cannot set up more than one pseudo-locked region in a cache
 162          * hierarchy.
 163          */
 164         if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP &&
 165             rdtgroup_pseudo_locked_in_hierarchy(d)) {
 166                 rdt_last_cmd_puts("Pseudo-locked region in hierarchy\n");
 167                 return -EINVAL;
 168         }
 169
 170         if (!cbm_validate(data->buf, &cbm_val, r))
 171                 return -EINVAL;
 172
 173         if ((rdtgrp->mode == RDT_MODE_EXCLUSIVE ||
 174              rdtgrp->mode == RDT_MODE_SHAREABLE) &&
 175             rdtgroup_cbm_overlaps_pseudo_locked(d, cbm_val)) {
 176                 rdt_last_cmd_puts("CBM overlaps with pseudo-locked region\n");
 177                 return -EINVAL;
 178         }
 179
 180         /*
 181          * The CBM may not overlap with the CBM of another closid if
 182          * either is exclusive.
 183          */
 184         if (rdtgroup_cbm_overlaps(s, d, cbm_val, rdtgrp->closid, true)) {
 185                 rdt_last_cmd_puts("Overlaps with exclusive group\n");
 186                 return -EINVAL;
 187         }
 188
 189         if (rdtgroup_cbm_overlaps(s, d, cbm_val, rdtgrp->closid, false)) {
 190                 if (rdtgrp->mode == RDT_MODE_EXCLUSIVE ||
 191                     rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
 192                         rdt_last_cmd_puts("Overlaps with other group\n");
 193                         return -EINVAL;
 194                 }
 195         }
 196
 197         cfg->new_ctrl = cbm_val;
 198         cfg->have_new_ctrl = true;
 199
 200         return 0;
 201 }
 202
 203 /*
 204  * For each domain in this resource we expect to find a series of:
 205  *      id=mask
 206  * separated by ";". The "id" is in decimal, and must match one of
 207  * the "id"s for this resource.
 208  */
 209 static int parse_line(char *line, struct resctrl_schema *s,
 210                       struct rdtgroup *rdtgrp)
 211 {
 212         enum resctrl_conf_type t = s->conf_type;
 213         struct resctrl_staged_config *cfg;
 214         struct rdt_resource *r = s->res;
 215         struct rdt_parse_data data;
 216         struct rdt_ctrl_domain *d;
 217         char *dom = NULL, *id;
 218         unsigned long dom_id;
 219
 220         /* Walking r->domains, ensure it can't race with cpuhp */
 221         lockdep_assert_cpus_held();
 222
 223         if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP &&
 224             (r->rid == RDT_RESOURCE_MBA || r->rid == RDT_RESOURCE_SMBA)) {
 225                 rdt_last_cmd_puts("Cannot pseudo-lock MBA resource\n");
 226                 return -EINVAL;
 227         }
 228
 229 next:
 230         if (!line || line[0] == '\0')
 231                 return 0;
 232         dom = strsep(&line, ";");
 233         id = strsep(&dom, "=");
 234         if (!dom || kstrtoul(id, 10, &dom_id)) {
 235                 rdt_last_cmd_puts("Missing '=' or non-numeric domain\n");
 236                 return -EINVAL;
 237         }
 238         dom = strim(dom);
 239         list_for_each_entry(d, &r->ctrl_domains, hdr.list) {
 240                 if (d->hdr.id == dom_id) {
 241                         data.buf = dom;
 242                         data.rdtgrp = rdtgrp;
 243                         if (r->parse_ctrlval(&data, s, d))
 244                                 return -EINVAL;
 245                         if (rdtgrp->mode ==  RDT_MODE_PSEUDO_LOCKSETUP) {
 246                                 cfg = &d->staged_config[t];
 247                                 /*
 248                                  * In pseudo-locking setup mode and just
 249                                  * parsed a valid CBM that should be
 250                                  * pseudo-locked. Only one locked region per
 251                                  * resource group and domain so just do
 252                                  * the required initialization for single
 253                                  * region and return.
 254                                  */
 255                                 rdtgrp->plr->s = s;
 256                                 rdtgrp->plr->d = d;
 257                                 rdtgrp->plr->cbm = cfg->new_ctrl;
 258                                 d->plr = rdtgrp->plr;
 259                                 return 0;
 260                         }
 261                         goto next;
 262                 }
 263         }
 264         return -EINVAL;
 265 }
 266
 267 static u32 get_config_index(u32 closid, enum resctrl_conf_type type)
 268 {
 269         switch (type) {
 270         default:
 271         case CDP_NONE:
 272                 return closid;
 273         case CDP_CODE:
 274                 return closid * 2 + 1;
 275         case CDP_DATA:
 276                 return closid * 2;
 277         }
 278 }
 279
 280 int resctrl_arch_update_one(struct rdt_resource *r, struct rdt_ctrl_domain *d,
 281                             u32 closid, enum resctrl_conf_type t, u32 cfg_val)
 282 {
 283         struct rdt_hw_ctrl_domain *hw_dom = resctrl_to_arch_ctrl_dom(d);
 284         struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
 285         u32 idx = get_config_index(closid, t);
 286         struct msr_param msr_param;
 287
 288         if (!cpumask_test_cpu(smp_processor_id(), &d->hdr.cpu_mask))
 289                 return -EINVAL;
 290
 291         hw_dom->ctrl_val[idx] = cfg_val;
 292
 293         msr_param.res = r;
 294         msr_param.dom = d;
 295         msr_param.low = idx;
 296         msr_param.high = idx + 1;
 297         hw_res->msr_update(&msr_param);
 298
 299         return 0;
 300 }
 301
 302 int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid)
 303 {
 304         struct resctrl_staged_config *cfg;
 305         struct rdt_hw_ctrl_domain *hw_dom;
 306         struct msr_param msr_param;
 307         struct rdt_ctrl_domain *d;
 308         enum resctrl_conf_type t;
 309         u32 idx;
 310
 311         /* Walking r->domains, ensure it can't race with cpuhp */
 312         lockdep_assert_cpus_held();
 313
 314         list_for_each_entry(d, &r->ctrl_domains, hdr.list) {
 315                 hw_dom = resctrl_to_arch_ctrl_dom(d);
 316                 msr_param.res = NULL;
 317                 for (t = 0; t < CDP_NUM_TYPES; t++) {
 318                         cfg = &hw_dom->d_resctrl.staged_config[t];
 319                         if (!cfg->have_new_ctrl)
 320                                 continue;
 321
 322                         idx = get_config_index(closid, t);
 323                         if (cfg->new_ctrl == hw_dom->ctrl_val[idx])
 324                                 continue;
 325                         hw_dom->ctrl_val[idx] = cfg->new_ctrl;
 326
 327                         if (!msr_param.res) {
 328                                 msr_param.low = idx;
 329                                 msr_param.high = msr_param.low + 1;
 330                                 msr_param.res = r;
 331                                 msr_param.dom = d;
 332                         } else {
 333                                 msr_param.low = min(msr_param.low, idx);
 334                                 msr_param.high = max(msr_param.high, idx + 1);
 335                         }
 336                 }
 337                 if (msr_param.res)
 338                         smp_call_function_any(&d->hdr.cpu_mask, rdt_ctrl_update, &msr_param, 1);
 339         }
 340
 341         return 0;
 342 }
 343
 344 static int rdtgroup_parse_resource(char *resname, char *tok,
 345                                    struct rdtgroup *rdtgrp)
 346 {
 347         struct resctrl_schema *s;
 348
 349         list_for_each_entry(s, &resctrl_schema_all, list) {
 350                 if (!strcmp(resname, s->name) && rdtgrp->closid < s->num_closid)
 351                         return parse_line(tok, s, rdtgrp);
 352         }
 353         rdt_last_cmd_printf("Unknown or unsupported resource name '%s'\n", resname);
 354         return -EINVAL;
 355 }
 356
 357 ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of,
 358                                 char *buf, size_t nbytes, loff_t off)
 359 {
 360         struct resctrl_schema *s;
 361         struct rdtgroup *rdtgrp;
 362         struct rdt_resource *r;
 363         char *tok, *resname;
 364         int ret = 0;
 365
 366         /* Valid input requires a trailing newline */
 367         if (nbytes == 0 || buf[nbytes - 1] != '\n')
 368                 return -EINVAL;
 369         buf[nbytes - 1] = '\0';
 370
 371         rdtgrp = rdtgroup_kn_lock_live(of->kn);
 372         if (!rdtgrp) {
 373                 rdtgroup_kn_unlock(of->kn);
 374                 return -ENOENT;
 375         }
 376         rdt_last_cmd_clear();
 377
 378         /*
 379          * No changes to pseudo-locked region allowed. It has to be removed
 380          * and re-created instead.
 381          */
 382         if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
 383                 ret = -EINVAL;
 384                 rdt_last_cmd_puts("Resource group is pseudo-locked\n");
 385                 goto out;
 386         }
 387
 388         rdt_staged_configs_clear();
 389
 390         while ((tok = strsep(&buf, "\n")) != NULL) {
 391                 resname = strim(strsep(&tok, ":"));
 392                 if (!tok) {
 393                         rdt_last_cmd_puts("Missing ':'\n");
 394                         ret = -EINVAL;
 395                         goto out;
 396                 }
 397                 if (tok[0] == '\0') {
 398                         rdt_last_cmd_printf("Missing '%s' value\n", resname);
 399                         ret = -EINVAL;
 400                         goto out;
 401                 }
 402                 ret = rdtgroup_parse_resource(resname, tok, rdtgrp);
 403                 if (ret)
 404                         goto out;
 405         }
 406
 407         list_for_each_entry(s, &resctrl_schema_all, list) {
 408                 r = s->res;
 409
 410                 /*
 411                  * Writes to mba_sc resources update the software controller,
 412                  * not the control MSR.
 413                  */
 414                 if (is_mba_sc(r))
 415                         continue;
 416
 417                 ret = resctrl_arch_update_domains(r, rdtgrp->closid);
 418                 if (ret)
 419                         goto out;
 420         }
 421
 422         if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
 423                 /*
 424                  * If pseudo-locking fails we keep the resource group in
 425                  * mode RDT_MODE_PSEUDO_LOCKSETUP with its class of service
 426                  * active and updated for just the domain the pseudo-locked
 427                  * region was requested for.
 428                  */
 429                 ret = rdtgroup_pseudo_lock_create(rdtgrp);
 430         }
 431
 432 out:
 433         rdt_staged_configs_clear();
 434         rdtgroup_kn_unlock(of->kn);
 435         return ret ?: nbytes;
 436 }
 437
 438 u32 resctrl_arch_get_config(struct rdt_resource *r, struct rdt_ctrl_domain *d,
 439                             u32 closid, enum resctrl_conf_type type)
 440 {
 441         struct rdt_hw_ctrl_domain *hw_dom = resctrl_to_arch_ctrl_dom(d);
 442         u32 idx = get_config_index(closid, type);
 443
 444         return hw_dom->ctrl_val[idx];
 445 }
 446
 447 static void show_doms(struct seq_file *s, struct resctrl_schema *schema, int closid)
 448 {
 449         struct rdt_resource *r = schema->res;
 450         struct rdt_ctrl_domain *dom;
 451         bool sep = false;
 452         u32 ctrl_val;
 453
 454         /* Walking r->domains, ensure it can't race with cpuhp */
 455         lockdep_assert_cpus_held();
 456
 457         seq_printf(s, "%*s:", max_name_width, schema->name);
 458         list_for_each_entry(dom, &r->ctrl_domains, hdr.list) {
 459                 if (sep)
 460                         seq_puts(s, ";");
 461
 462                 if (is_mba_sc(r))
 463                         ctrl_val = dom->mbps_val[closid];
 464                 else
 465                         ctrl_val = resctrl_arch_get_config(r, dom, closid,
 466                                                            schema->conf_type);
 467
 468                 seq_printf(s, r->format_str, dom->hdr.id, max_data_width,
 469                            ctrl_val);
 470                 sep = true;
 471         }
 472         seq_puts(s, "\n");
 473 }
 474
 475 int rdtgroup_schemata_show(struct kernfs_open_file *of,
 476                            struct seq_file *s, void *v)
 477 {
 478         struct resctrl_schema *schema;
 479         struct rdtgroup *rdtgrp;
 480         int ret = 0;
 481         u32 closid;
 482
 483         rdtgrp = rdtgroup_kn_lock_live(of->kn);
 484         if (rdtgrp) {
 485                 if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
 486                         list_for_each_entry(schema, &resctrl_schema_all, list) {
 487                                 seq_printf(s, "%s:uninitialized\n", schema->name);
 488                         }
 489                 } else if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
 490                         if (!rdtgrp->plr->d) {
 491                                 rdt_last_cmd_clear();
 492                                 rdt_last_cmd_puts("Cache domain offline\n");
 493                                 ret = -ENODEV;
 494                         } else {
 495                                 seq_printf(s, "%s:%d=%x\n",
 496                                            rdtgrp->plr->s->res->name,
 497                                            rdtgrp->plr->d->hdr.id,
 498                                            rdtgrp->plr->cbm);
 499                         }
 500                 } else {
 501                         closid = rdtgrp->closid;
 502                         list_for_each_entry(schema, &resctrl_schema_all, list) {
 503                                 if (closid < schema->num_closid)
 504                                         show_doms(s, schema, closid);
 505                         }
 506                 }
 507         } else {
 508                 ret = -ENOENT;
 509         }
 510         rdtgroup_kn_unlock(of->kn);
 511         return ret;
 512 }
 513
 514 static int smp_mon_event_count(void *arg)
 515 {
 516         mon_event_count(arg);
 517
 518         return 0;
 519 }
 520
 521 void mon_event_read(struct rmid_read *rr, struct rdt_resource *r,
 522                     struct rdt_mon_domain *d, struct rdtgroup *rdtgrp,
 523                     cpumask_t *cpumask, int evtid, int first)
 524 {
 525         int cpu;
 526
 527         /* When picking a CPU from cpu_mask, ensure it can't race with cpuhp */
 528         lockdep_assert_cpus_held();
 529
 530         /*
 531          * Setup the parameters to pass to mon_event_count() to read the data.
 532          */
 533         rr->rgrp = rdtgrp;
 534         rr->evtid = evtid;
 535         rr->r = r;
 536         rr->d = d;
 537         rr->first = first;
 538         rr->arch_mon_ctx = resctrl_arch_mon_ctx_alloc(r, evtid);
 539         if (IS_ERR(rr->arch_mon_ctx)) {
 540                 rr->err = -EINVAL;
 541                 return;
 542         }
 543
 544         cpu = cpumask_any_housekeeping(cpumask, RESCTRL_PICK_ANY_CPU);
 545
 546         /*
 547          * cpumask_any_housekeeping() prefers housekeeping CPUs, but
 548          * are all the CPUs nohz_full? If yes, pick a CPU to IPI.
 549          * MPAM's resctrl_arch_rmid_read() is unable to read the
 550          * counters on some platforms if its called in IRQ context.
 551          */
 552         if (tick_nohz_full_cpu(cpu))
 553                 smp_call_function_any(cpumask, mon_event_count, rr, 1);
 554         else
 555                 smp_call_on_cpu(cpu, smp_mon_event_count, rr, false);
 556
 557         resctrl_arch_mon_ctx_free(r, evtid, rr->arch_mon_ctx);
 558 }
 559
 560 int rdtgroup_mondata_show(struct seq_file *m, void *arg)
 561 {
 562         struct kernfs_open_file *of = m->private;
 563         struct rdt_domain_hdr *hdr;
 564         struct rmid_read rr = {0};
 565         struct rdt_mon_domain *d;
 566         u32 resid, evtid, domid;
 567         struct rdtgroup *rdtgrp;
 568         struct rdt_resource *r;
 569         union mon_data_bits md;
 570         int ret = 0;
 571
 572         rdtgrp = rdtgroup_kn_lock_live(of->kn);
 573         if (!rdtgrp) {
 574                 ret = -ENOENT;
 575                 goto out;
 576         }
 577
 578         md.priv = of->kn->priv;
 579         resid = md.u.rid;
 580         domid = md.u.domid;
 581         evtid = md.u.evtid;
 582         r = &rdt_resources_all[resid].r_resctrl;
 583
 584         if (md.u.sum) {
 585                 /*
 586                  * This file requires summing across all domains that share
 587                  * the L3 cache id that was provided in the "domid" field of the
 588                  * mon_data_bits union. Search all domains in the resource for
 589                  * one that matches this cache id.
 590                  */
 591                 list_for_each_entry(d, &r->mon_domains, hdr.list) {
 592                         if (d->ci->id == domid) {
 593                                 rr.ci = d->ci;
 594                                 mon_event_read(&rr, r, NULL, rdtgrp,
 595                                                &d->ci->shared_cpu_map, evtid, false);
 596                                 goto checkresult;
 597                         }
 598                 }
 599                 ret = -ENOENT;
 600                 goto out;
 601         } else {
 602                 /*
 603                  * This file provides data from a single domain. Search
 604                  * the resource to find the domain with "domid".
 605                  */
 606                 hdr = rdt_find_domain(&r->mon_domains, domid, NULL);
 607                 if (!hdr || WARN_ON_ONCE(hdr->type != RESCTRL_MON_DOMAIN)) {
 608                         ret = -ENOENT;
 609                         goto out;
 610                 }
 611                 d = container_of(hdr, struct rdt_mon_domain, hdr);
 612                 mon_event_read(&rr, r, d, rdtgrp, &d->hdr.cpu_mask, evtid, false);
 613         }
 614
 615 checkresult:
 616
 617         if (rr.err == -EIO)
 618                 seq_puts(m, "Error\n");
 619         else if (rr.err == -EINVAL)
 620                 seq_puts(m, "Unavailable\n");
 621         else
 622                 seq_printf(m, "%llu\n", rr.val);
 623
 624 out:
 625         rdtgroup_kn_unlock(of->kn);
 626         return ret;
 627 }