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 <fenghua.yu@intel.com>
  10  *    Tony Luck <tony.luck@intel.com>
  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 "internal.h"
  23
  24 /*
  25  * Check whether MBA bandwidth percentage value is correct. The value is
  26  * checked against the minimum and max bandwidth values specified by the
  27  * hardware. The allocated bandwidth percentage is rounded to the next
  28  * control step available on the hardware.
  29  */
  30 static bool bw_validate(char *buf, unsigned long *data, struct rdt_resource *r)
  31 {
  32         unsigned long bw;
  33         int ret;
  34
  35         /*
  36          * Only linear delay values is supported for current Intel SKUs.
  37          */
  38         if (!r->membw.delay_linear && r->membw.arch_needs_linear) {
  39                 rdt_last_cmd_puts("No support for non-linear MB domains\n");
  40                 return false;
  41         }
  42
  43         ret = kstrtoul(buf, 10, &bw);
  44         if (ret) {
  45                 rdt_last_cmd_printf("Non-decimal digit in MB value %s\n", buf);
  46                 return false;
  47         }
  48
  49         if ((bw < r->membw.min_bw || bw > r->default_ctrl) &&
  50             !is_mba_sc(r)) {
  51                 rdt_last_cmd_printf("MB value %ld out of range [%d,%d]\n", bw,
  52                                     r->membw.min_bw, r->default_ctrl);
  53                 return false;
  54         }
  55
  56         *data = roundup(bw, (unsigned long)r->membw.bw_gran);
  57         return true;
  58 }
  59
  60 int parse_bw(struct rdt_parse_data *data, struct rdt_resource *r,
  61              struct rdt_domain *d)
  62 {
  63         unsigned long bw_val;
  64
  65         if (d->have_new_ctrl) {
  66                 rdt_last_cmd_printf("Duplicate domain %d\n", d->id);
  67                 return -EINVAL;
  68         }
  69
  70         if (!bw_validate(data->buf, &bw_val, r))
  71                 return -EINVAL;
  72         d->new_ctrl = bw_val;
  73         d->have_new_ctrl = true;
  74
  75         return 0;
  76 }
  77
  78 /*
  79  * Check whether a cache bit mask is valid.
  80  * For Intel the SDM says:
  81  *      Please note that all (and only) contiguous '1' combinations
  82  *      are allowed (e.g. FFFFH, 0FF0H, 003CH, etc.).
  83  * Additionally Haswell requires at least two bits set.
  84  * AMD allows non-contiguous bitmasks.
  85  */
  86 static bool cbm_validate(char *buf, u32 *data, struct rdt_resource *r)
  87 {
  88         unsigned long first_bit, zero_bit, val;
  89         unsigned int cbm_len = r->cache.cbm_len;
  90         int ret;
  91
  92         ret = kstrtoul(buf, 16, &val);
  93         if (ret) {
  94                 rdt_last_cmd_printf("Non-hex character in the mask %s\n", buf);
  95                 return false;
  96         }
  97
  98         if ((!r->cache.arch_has_empty_bitmaps && val == 0) ||
  99             val > r->default_ctrl) {
 100                 rdt_last_cmd_puts("Mask out of range\n");
 101                 return false;
 102         }
 103
 104         first_bit = find_first_bit(&val, cbm_len);
 105         zero_bit = find_next_zero_bit(&val, cbm_len, first_bit);
 106
 107         /* Are non-contiguous bitmaps allowed? */
 108         if (!r->cache.arch_has_sparse_bitmaps &&
 109             (find_next_bit(&val, cbm_len, zero_bit) < cbm_len)) {
 110                 rdt_last_cmd_printf("The mask %lx has non-consecutive 1-bits\n", val);
 111                 return false;
 112         }
 113
 114         if ((zero_bit - first_bit) < r->cache.min_cbm_bits) {
 115                 rdt_last_cmd_printf("Need at least %d bits in the mask\n",
 116                                     r->cache.min_cbm_bits);
 117                 return false;
 118         }
 119
 120         *data = val;
 121         return true;
 122 }
 123
 124 /*
 125  * Read one cache bit mask (hex). Check that it is valid for the current
 126  * resource type.
 127  */
 128 int parse_cbm(struct rdt_parse_data *data, struct rdt_resource *r,
 129               struct rdt_domain *d)
 130 {
 131         struct rdtgroup *rdtgrp = data->rdtgrp;
 132         u32 cbm_val;
 133
 134         if (d->have_new_ctrl) {
 135                 rdt_last_cmd_printf("Duplicate domain %d\n", d->id);
 136                 return -EINVAL;
 137         }
 138
 139         /*
 140          * Cannot set up more than one pseudo-locked region in a cache
 141          * hierarchy.
 142          */
 143         if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP &&
 144             rdtgroup_pseudo_locked_in_hierarchy(d)) {
 145                 rdt_last_cmd_puts("Pseudo-locked region in hierarchy\n");
 146                 return -EINVAL;
 147         }
 148
 149         if (!cbm_validate(data->buf, &cbm_val, r))
 150                 return -EINVAL;
 151
 152         if ((rdtgrp->mode == RDT_MODE_EXCLUSIVE ||
 153              rdtgrp->mode == RDT_MODE_SHAREABLE) &&
 154             rdtgroup_cbm_overlaps_pseudo_locked(d, cbm_val)) {
 155                 rdt_last_cmd_puts("CBM overlaps with pseudo-locked region\n");
 156                 return -EINVAL;
 157         }
 158
 159         /*
 160          * The CBM may not overlap with the CBM of another closid if
 161          * either is exclusive.
 162          */
 163         if (rdtgroup_cbm_overlaps(r, d, cbm_val, rdtgrp->closid, true)) {
 164                 rdt_last_cmd_puts("Overlaps with exclusive group\n");
 165                 return -EINVAL;
 166         }
 167
 168         if (rdtgroup_cbm_overlaps(r, d, cbm_val, rdtgrp->closid, false)) {
 169                 if (rdtgrp->mode == RDT_MODE_EXCLUSIVE ||
 170                     rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
 171                         rdt_last_cmd_puts("Overlaps with other group\n");
 172                         return -EINVAL;
 173                 }
 174         }
 175
 176         d->new_ctrl = cbm_val;
 177         d->have_new_ctrl = true;
 178
 179         return 0;
 180 }
 181
 182 /*
 183  * For each domain in this resource we expect to find a series of:
 184  *      id=mask
 185  * separated by ";". The "id" is in decimal, and must match one of
 186  * the "id"s for this resource.
 187  */
 188 static int parse_line(char *line, struct rdt_resource *r,
 189                       struct rdtgroup *rdtgrp)
 190 {
 191         struct rdt_parse_data data;
 192         char *dom = NULL, *id;
 193         struct rdt_domain *d;
 194         unsigned long dom_id;
 195
 196         if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP &&
 197             r->rid == RDT_RESOURCE_MBA) {
 198                 rdt_last_cmd_puts("Cannot pseudo-lock MBA resource\n");
 199                 return -EINVAL;
 200         }
 201
 202 next:
 203         if (!line || line[0] == '\0')
 204                 return 0;
 205         dom = strsep(&line, ";");
 206         id = strsep(&dom, "=");
 207         if (!dom || kstrtoul(id, 10, &dom_id)) {
 208                 rdt_last_cmd_puts("Missing '=' or non-numeric domain\n");
 209                 return -EINVAL;
 210         }
 211         dom = strim(dom);
 212         list_for_each_entry(d, &r->domains, list) {
 213                 if (d->id == dom_id) {
 214                         data.buf = dom;
 215                         data.rdtgrp = rdtgrp;
 216                         if (r->parse_ctrlval(&data, r, d))
 217                                 return -EINVAL;
 218                         if (rdtgrp->mode ==  RDT_MODE_PSEUDO_LOCKSETUP) {
 219                                 /*
 220                                  * In pseudo-locking setup mode and just
 221                                  * parsed a valid CBM that should be
 222                                  * pseudo-locked. Only one locked region per
 223                                  * resource group and domain so just do
 224                                  * the required initialization for single
 225                                  * region and return.
 226                                  */
 227                                 rdtgrp->plr->r = r;
 228                                 rdtgrp->plr->d = d;
 229                                 rdtgrp->plr->cbm = d->new_ctrl;
 230                                 d->plr = rdtgrp->plr;
 231                                 return 0;
 232                         }
 233                         goto next;
 234                 }
 235         }
 236         return -EINVAL;
 237 }
 238
 239 int update_domains(struct rdt_resource *r, int closid)
 240 {
 241         struct msr_param msr_param;
 242         cpumask_var_t cpu_mask;
 243         struct rdt_domain *d;
 244         bool mba_sc;
 245         u32 *dc;
 246         int cpu;
 247
 248         if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL))
 249                 return -ENOMEM;
 250
 251         msr_param.low = closid;
 252         msr_param.high = msr_param.low + 1;
 253         msr_param.res = r;
 254
 255         mba_sc = is_mba_sc(r);
 256         list_for_each_entry(d, &r->domains, list) {
 257                 dc = !mba_sc ? d->ctrl_val : d->mbps_val;
 258                 if (d->have_new_ctrl && d->new_ctrl != dc[closid]) {
 259                         cpumask_set_cpu(cpumask_any(&d->cpu_mask), cpu_mask);
 260                         dc[closid] = d->new_ctrl;
 261                 }
 262         }
 263
 264         /*
 265          * Avoid writing the control msr with control values when
 266          * MBA software controller is enabled
 267          */
 268         if (cpumask_empty(cpu_mask) || mba_sc)
 269                 goto done;
 270         cpu = get_cpu();
 271         /* Update resource control msr on this CPU if it's in cpu_mask. */
 272         if (cpumask_test_cpu(cpu, cpu_mask))
 273                 rdt_ctrl_update(&msr_param);
 274         /* Update resource control msr on other CPUs. */
 275         smp_call_function_many(cpu_mask, rdt_ctrl_update, &msr_param, 1);
 276         put_cpu();
 277
 278 done:
 279         free_cpumask_var(cpu_mask);
 280
 281         return 0;
 282 }
 283
 284 static int rdtgroup_parse_resource(char *resname, char *tok,
 285                                    struct rdtgroup *rdtgrp)
 286 {
 287         struct rdt_resource *r;
 288
 289         for_each_alloc_enabled_rdt_resource(r) {
 290                 if (!strcmp(resname, r->name) && rdtgrp->closid < r->num_closid)
 291                         return parse_line(tok, r, rdtgrp);
 292         }
 293         rdt_last_cmd_printf("Unknown or unsupported resource name '%s'\n", resname);
 294         return -EINVAL;
 295 }
 296
 297 ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of,
 298                                 char *buf, size_t nbytes, loff_t off)
 299 {
 300         struct rdtgroup *rdtgrp;
 301         struct rdt_domain *dom;
 302         struct rdt_resource *r;
 303         char *tok, *resname;
 304         int ret = 0;
 305
 306         /* Valid input requires a trailing newline */
 307         if (nbytes == 0 || buf[nbytes - 1] != '\n')
 308                 return -EINVAL;
 309         buf[nbytes - 1] = '\0';
 310
 311         cpus_read_lock();
 312         rdtgrp = rdtgroup_kn_lock_live(of->kn);
 313         if (!rdtgrp) {
 314                 rdtgroup_kn_unlock(of->kn);
 315                 cpus_read_unlock();
 316                 return -ENOENT;
 317         }
 318         rdt_last_cmd_clear();
 319
 320         /*
 321          * No changes to pseudo-locked region allowed. It has to be removed
 322          * and re-created instead.
 323          */
 324         if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
 325                 ret = -EINVAL;
 326                 rdt_last_cmd_puts("Resource group is pseudo-locked\n");
 327                 goto out;
 328         }
 329
 330         for_each_alloc_enabled_rdt_resource(r) {
 331                 list_for_each_entry(dom, &r->domains, list)
 332                         dom->have_new_ctrl = false;
 333         }
 334
 335         while ((tok = strsep(&buf, "\n")) != NULL) {
 336                 resname = strim(strsep(&tok, ":"));
 337                 if (!tok) {
 338                         rdt_last_cmd_puts("Missing ':'\n");
 339                         ret = -EINVAL;
 340                         goto out;
 341                 }
 342                 if (tok[0] == '\0') {
 343                         rdt_last_cmd_printf("Missing '%s' value\n", resname);
 344                         ret = -EINVAL;
 345                         goto out;
 346                 }
 347                 ret = rdtgroup_parse_resource(resname, tok, rdtgrp);
 348                 if (ret)
 349                         goto out;
 350         }
 351
 352         for_each_alloc_enabled_rdt_resource(r) {
 353                 ret = update_domains(r, rdtgrp->closid);
 354                 if (ret)
 355                         goto out;
 356         }
 357
 358         if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
 359                 /*
 360                  * If pseudo-locking fails we keep the resource group in
 361                  * mode RDT_MODE_PSEUDO_LOCKSETUP with its class of service
 362                  * active and updated for just the domain the pseudo-locked
 363                  * region was requested for.
 364                  */
 365                 ret = rdtgroup_pseudo_lock_create(rdtgrp);
 366         }
 367
 368 out:
 369         rdtgroup_kn_unlock(of->kn);
 370         cpus_read_unlock();
 371         return ret ?: nbytes;
 372 }
 373
 374 static void show_doms(struct seq_file *s, struct rdt_resource *r, int closid)
 375 {
 376         struct rdt_domain *dom;
 377         bool sep = false;
 378         u32 ctrl_val;
 379
 380         seq_printf(s, "%*s:", max_name_width, r->name);
 381         list_for_each_entry(dom, &r->domains, list) {
 382                 if (sep)
 383                         seq_puts(s, ";");
 384
 385                 ctrl_val = (!is_mba_sc(r) ? dom->ctrl_val[closid] :
 386                             dom->mbps_val[closid]);
 387                 seq_printf(s, r->format_str, dom->id, max_data_width,
 388                            ctrl_val);
 389                 sep = true;
 390         }
 391         seq_puts(s, "\n");
 392 }
 393
 394 int rdtgroup_schemata_show(struct kernfs_open_file *of,
 395                            struct seq_file *s, void *v)
 396 {
 397         struct rdtgroup *rdtgrp;
 398         struct rdt_resource *r;
 399         int ret = 0;
 400         u32 closid;
 401
 402         rdtgrp = rdtgroup_kn_lock_live(of->kn);
 403         if (rdtgrp) {
 404                 if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
 405                         for_each_alloc_enabled_rdt_resource(r)
 406                                 seq_printf(s, "%s:uninitialized\n", r->name);
 407                 } else if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
 408                         if (!rdtgrp->plr->d) {
 409                                 rdt_last_cmd_clear();
 410                                 rdt_last_cmd_puts("Cache domain offline\n");
 411                                 ret = -ENODEV;
 412                         } else {
 413                                 seq_printf(s, "%s:%d=%x\n",
 414                                            rdtgrp->plr->r->name,
 415                                            rdtgrp->plr->d->id,
 416                                            rdtgrp->plr->cbm);
 417                         }
 418                 } else {
 419                         closid = rdtgrp->closid;
 420                         for_each_alloc_enabled_rdt_resource(r) {
 421                                 if (closid < r->num_closid)
 422                                         show_doms(s, r, closid);
 423                         }
 424                 }
 425         } else {
 426                 ret = -ENOENT;
 427         }
 428         rdtgroup_kn_unlock(of->kn);
 429         return ret;
 430 }
 431
 432 void mon_event_read(struct rmid_read *rr, struct rdt_resource *r,
 433                     struct rdt_domain *d, struct rdtgroup *rdtgrp,
 434                     int evtid, int first)
 435 {
 436         /*
 437          * setup the parameters to send to the IPI to read the data.
 438          */
 439         rr->rgrp = rdtgrp;
 440         rr->evtid = evtid;
 441         rr->r = r;
 442         rr->d = d;
 443         rr->val = 0;
 444         rr->first = first;
 445
 446         smp_call_function_any(&d->cpu_mask, mon_event_count, rr, 1);
 447 }
 448
 449 int rdtgroup_mondata_show(struct seq_file *m, void *arg)
 450 {
 451         struct kernfs_open_file *of = m->private;
 452         u32 resid, evtid, domid;
 453         struct rdtgroup *rdtgrp;
 454         struct rdt_resource *r;
 455         union mon_data_bits md;
 456         struct rdt_domain *d;
 457         struct rmid_read rr;
 458         int ret = 0;
 459
 460         rdtgrp = rdtgroup_kn_lock_live(of->kn);
 461         if (!rdtgrp) {
 462                 ret = -ENOENT;
 463                 goto out;
 464         }
 465
 466         md.priv = of->kn->priv;
 467         resid = md.u.rid;
 468         domid = md.u.domid;
 469         evtid = md.u.evtid;
 470
 471         r = &rdt_resources_all[resid];
 472         d = rdt_find_domain(r, domid, NULL);
 473         if (IS_ERR_OR_NULL(d)) {
 474                 ret = -ENOENT;
 475                 goto out;
 476         }
 477
 478         mon_event_read(&rr, r, d, rdtgrp, evtid, false);
 479
 480         if (rr.val & RMID_VAL_ERROR)
 481                 seq_puts(m, "Error\n");
 482         else if (rr.val & RMID_VAL_UNAVAIL)
 483                 seq_puts(m, "Unavailable\n");
 484         else
 485                 seq_printf(m, "%llu\n", rr.val * r->mon_scale);
 486
 487 out:
 488         rdtgroup_kn_unlock(of->kn);
 489         return ret;
 490 }