arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c

   1 /*
   2  * Resource Director Technology(RDT)
   3  * - Cache Allocation code.
   4  *
   5  * Copyright (C) 2016 Intel Corporation
   6  *
   7  * Authors:
   8  *    Fenghua Yu <fenghua.yu@intel.com>
   9  *    Tony Luck <tony.luck@intel.com>
  10  *
  11  * This program is free software; you can redistribute it and/or modify it
  12  * under the terms and conditions of the GNU General Public License,
  13  * version 2, as published by the Free Software Foundation.
  14  *
  15  * This program is distributed in the hope it will be useful, but WITHOUT
  16  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  17  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  18  * more details.
  19  *
  20  * More information about RDT be found in the Intel (R) x86 Architecture
  21  * Software Developer Manual June 2016, volume 3, section 17.17.
  22  */
  23
  24 #define pr_fmt(fmt)     KBUILD_MODNAME ": " fmt
  25
  26 #include <linux/kernfs.h>
  27 #include <linux/seq_file.h>
  28 #include <linux/slab.h>
  29 #include "intel_rdt.h"
  30
  31 /*
  32  * Check whether MBA bandwidth percentage value is correct. The value is
  33  * checked against the minimum and max bandwidth values specified by the
  34  * hardware. The allocated bandwidth percentage is rounded to the next
  35  * control step available on the hardware.
  36  */
  37 static bool bw_validate(char *buf, unsigned long *data, struct rdt_resource *r)
  38 {
  39         unsigned long bw;
  40         int ret;
  41
  42         /*
  43          * Only linear delay values is supported for current Intel SKUs.
  44          */
  45         if (!r->membw.delay_linear) {
  46                 rdt_last_cmd_puts("No support for non-linear MB domains\n");
  47                 return false;
  48         }
  49
  50         ret = kstrtoul(buf, 10, &bw);
  51         if (ret) {
  52                 rdt_last_cmd_printf("Non-decimal digit in MB value %s\n", buf);
  53                 return false;
  54         }
  55
  56         if (bw < r->membw.min_bw || bw > r->default_ctrl) {
  57                 rdt_last_cmd_printf("MB value %ld out of range [%d,%d]\n", bw,
  58                                     r->membw.min_bw, r->default_ctrl);
  59                 return false;
  60         }
  61
  62         *data = roundup(bw, (unsigned long)r->membw.bw_gran);
  63         return true;
  64 }
  65
  66 int parse_bw(char *buf, struct rdt_resource *r, struct rdt_domain *d)
  67 {
  68         unsigned long data;
  69
  70         if (d->have_new_ctrl) {
  71                 rdt_last_cmd_printf("duplicate domain %d\n", d->id);
  72                 return -EINVAL;
  73         }
  74
  75         if (!bw_validate(buf, &data, r))
  76                 return -EINVAL;
  77         d->new_ctrl = data;
  78         d->have_new_ctrl = true;
  79
  80         return 0;
  81 }
  82
  83 /*
  84  * Check whether a cache bit mask is valid. The SDM says:
  85  *      Please note that all (and only) contiguous '1' combinations
  86  *      are allowed (e.g. FFFFH, 0FF0H, 003CH, etc.).
  87  * Additionally Haswell requires at least two bits set.
  88  */
  89 static bool cbm_validate(char *buf, unsigned long *data, struct rdt_resource *r)
  90 {
  91         unsigned long first_bit, zero_bit, val;
  92         unsigned int cbm_len = r->cache.cbm_len;
  93         int ret;
  94
  95         ret = kstrtoul(buf, 16, &val);
  96         if (ret) {
  97                 rdt_last_cmd_printf("non-hex character in mask %s\n", buf);
  98                 return false;
  99         }
 100
 101         if (val == 0 || val > r->default_ctrl) {
 102                 rdt_last_cmd_puts("mask out of range\n");
 103                 return false;
 104         }
 105
 106         first_bit = find_first_bit(&val, cbm_len);
 107         zero_bit = find_next_zero_bit(&val, cbm_len, first_bit);
 108
 109         if (find_next_bit(&val, cbm_len, zero_bit) < cbm_len) {
 110                 rdt_last_cmd_printf("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 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(char *buf, struct rdt_resource *r, struct rdt_domain *d)
 129 {
 130         unsigned long data;
 131
 132         if (d->have_new_ctrl) {
 133                 rdt_last_cmd_printf("duplicate domain %d\n", d->id);
 134                 return -EINVAL;
 135         }
 136
 137         if(!cbm_validate(buf, &data, r))
 138                 return -EINVAL;
 139         d->new_ctrl = data;
 140         d->have_new_ctrl = true;
 141
 142         return 0;
 143 }
 144
 145 /*
 146  * For each domain in this resource we expect to find a series of:
 147  *      id=mask
 148  * separated by ";". The "id" is in decimal, and must match one of
 149  * the "id"s for this resource.
 150  */
 151 static int parse_line(char *line, struct rdt_resource *r)
 152 {
 153         char *dom = NULL, *id;
 154         struct rdt_domain *d;
 155         unsigned long dom_id;
 156
 157 next:
 158         if (!line || line[0] == '\0')
 159                 return 0;
 160         dom = strsep(&line, ";");
 161         id = strsep(&dom, "=");
 162         if (!dom || kstrtoul(id, 10, &dom_id)) {
 163                 rdt_last_cmd_puts("Missing '=' or non-numeric domain\n");
 164                 return -EINVAL;
 165         }
 166         dom = strim(dom);
 167         list_for_each_entry(d, &r->domains, list) {
 168                 if (d->id == dom_id) {
 169                         if (r->parse_ctrlval(dom, r, d))
 170                                 return -EINVAL;
 171                         goto next;
 172                 }
 173         }
 174         return -EINVAL;
 175 }
 176
 177 static int update_domains(struct rdt_resource *r, int closid)
 178 {
 179         struct msr_param msr_param;
 180         cpumask_var_t cpu_mask;
 181         struct rdt_domain *d;
 182         int cpu;
 183
 184         if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL))
 185                 return -ENOMEM;
 186
 187         msr_param.low = closid;
 188         msr_param.high = msr_param.low + 1;
 189         msr_param.res = r;
 190
 191         list_for_each_entry(d, &r->domains, list) {
 192                 if (d->have_new_ctrl && d->new_ctrl != d->ctrl_val[closid]) {
 193                         cpumask_set_cpu(cpumask_any(&d->cpu_mask), cpu_mask);
 194                         d->ctrl_val[closid] = d->new_ctrl;
 195                 }
 196         }
 197         if (cpumask_empty(cpu_mask))
 198                 goto done;
 199         cpu = get_cpu();
 200         /* Update CBM on this cpu if it's in cpu_mask. */
 201         if (cpumask_test_cpu(cpu, cpu_mask))
 202                 rdt_ctrl_update(&msr_param);
 203         /* Update CBM on other cpus. */
 204         smp_call_function_many(cpu_mask, rdt_ctrl_update, &msr_param, 1);
 205         put_cpu();
 206
 207 done:
 208         free_cpumask_var(cpu_mask);
 209
 210         return 0;
 211 }
 212
 213 static int rdtgroup_parse_resource(char *resname, char *tok, int closid)
 214 {
 215         struct rdt_resource *r;
 216
 217         for_each_alloc_enabled_rdt_resource(r) {
 218                 if (!strcmp(resname, r->name) && closid < r->num_closid)
 219                         return parse_line(tok, r);
 220         }
 221         rdt_last_cmd_printf("unknown/unsupported resource name '%s'\n", resname);
 222         return -EINVAL;
 223 }
 224
 225 ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of,
 226                                 char *buf, size_t nbytes, loff_t off)
 227 {
 228         struct rdtgroup *rdtgrp;
 229         struct rdt_domain *dom;
 230         struct rdt_resource *r;
 231         char *tok, *resname;
 232         int closid, ret = 0;
 233
 234         /* Valid input requires a trailing newline */
 235         if (nbytes == 0 || buf[nbytes - 1] != '\n')
 236                 return -EINVAL;
 237         buf[nbytes - 1] = '\0';
 238
 239         rdtgrp = rdtgroup_kn_lock_live(of->kn);
 240         if (!rdtgrp) {
 241                 rdtgroup_kn_unlock(of->kn);
 242                 return -ENOENT;
 243         }
 244         rdt_last_cmd_clear();
 245
 246         closid = rdtgrp->closid;
 247
 248         for_each_alloc_enabled_rdt_resource(r) {
 249                 list_for_each_entry(dom, &r->domains, list)
 250                         dom->have_new_ctrl = false;
 251         }
 252
 253         while ((tok = strsep(&buf, "\n")) != NULL) {
 254                 resname = strim(strsep(&tok, ":"));
 255                 if (!tok) {
 256                         rdt_last_cmd_puts("Missing ':'\n");
 257                         ret = -EINVAL;
 258                         goto out;
 259                 }
 260                 if (tok[0] == '\0') {
 261                         rdt_last_cmd_printf("Missing '%s' value\n", resname);
 262                         ret = -EINVAL;
 263                         goto out;
 264                 }
 265                 ret = rdtgroup_parse_resource(resname, tok, closid);
 266                 if (ret)
 267                         goto out;
 268         }
 269
 270         for_each_alloc_enabled_rdt_resource(r) {
 271                 ret = update_domains(r, closid);
 272                 if (ret)
 273                         goto out;
 274         }
 275
 276 out:
 277         rdtgroup_kn_unlock(of->kn);
 278         return ret ?: nbytes;
 279 }
 280
 281 static void show_doms(struct seq_file *s, struct rdt_resource *r, int closid)
 282 {
 283         struct rdt_domain *dom;
 284         bool sep = false;
 285
 286         seq_printf(s, "%*s:", max_name_width, r->name);
 287         list_for_each_entry(dom, &r->domains, list) {
 288                 if (sep)
 289                         seq_puts(s, ";");
 290                 seq_printf(s, r->format_str, dom->id, max_data_width,
 291                            dom->ctrl_val[closid]);
 292                 sep = true;
 293         }
 294         seq_puts(s, "\n");
 295 }
 296
 297 int rdtgroup_schemata_show(struct kernfs_open_file *of,
 298                            struct seq_file *s, void *v)
 299 {
 300         struct rdtgroup *rdtgrp;
 301         struct rdt_resource *r;
 302         int ret = 0;
 303         u32 closid;
 304
 305         rdtgrp = rdtgroup_kn_lock_live(of->kn);
 306         if (rdtgrp) {
 307                 closid = rdtgrp->closid;
 308                 for_each_alloc_enabled_rdt_resource(r) {
 309                         if (closid < r->num_closid)
 310                                 show_doms(s, r, closid);
 311                 }
 312         } else {
 313                 ret = -ENOENT;
 314         }
 315         rdtgroup_kn_unlock(of->kn);
 316         return ret;
 317 }
 318
 319 void mon_event_read(struct rmid_read *rr, struct rdt_domain *d,
 320                     struct rdtgroup *rdtgrp, int evtid, int first)
 321 {
 322         /*
 323          * setup the parameters to send to the IPI to read the data.
 324          */
 325         rr->rgrp = rdtgrp;
 326         rr->evtid = evtid;
 327         rr->d = d;
 328         rr->val = 0;
 329         rr->first = first;
 330
 331         smp_call_function_any(&d->cpu_mask, mon_event_count, rr, 1);
 332 }
 333
 334 int rdtgroup_mondata_show(struct seq_file *m, void *arg)
 335 {
 336         struct kernfs_open_file *of = m->private;
 337         u32 resid, evtid, domid;
 338         struct rdtgroup *rdtgrp;
 339         struct rdt_resource *r;
 340         union mon_data_bits md;
 341         struct rdt_domain *d;
 342         struct rmid_read rr;
 343         int ret = 0;
 344
 345         rdtgrp = rdtgroup_kn_lock_live(of->kn);
 346
 347         md.priv = of->kn->priv;
 348         resid = md.u.rid;
 349         domid = md.u.domid;
 350         evtid = md.u.evtid;
 351
 352         r = &rdt_resources_all[resid];
 353         d = rdt_find_domain(r, domid, NULL);
 354         if (!d) {
 355                 ret = -ENOENT;
 356                 goto out;
 357         }
 358
 359         mon_event_read(&rr, d, rdtgrp, evtid, false);
 360
 361         if (rr.val & RMID_VAL_ERROR)
 362                 seq_puts(m, "Error\n");
 363         else if (rr.val & RMID_VAL_UNAVAIL)
 364                 seq_puts(m, "Unavailable\n");
 365         else
 366                 seq_printf(m, "%llu\n", rr.val * r->mon_scale);
 367
 368 out:
 369         rdtgroup_kn_unlock(of->kn);
 370         return ret;
 371 }