2 * Resource Director Technology(RDT)
3 * - Cache Allocation code.
5 * Copyright (C) 2016 Intel Corporation
8 * Fenghua Yu <fenghua.yu@intel.com>
9 * Tony Luck <tony.luck@intel.com>
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.
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
20 * More information about RDT be found in the Intel (R) x86 Architecture
21 * Software Developer Manual June 2016, volume 3, section 17.17.
24 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
26 #include <linux/kernfs.h>
27 #include <linux/seq_file.h>
28 #include <linux/slab.h>
29 #include "intel_rdt.h"
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.
37 static bool bw_validate(char *buf, unsigned long *data, struct rdt_resource *r)
43 * Only linear delay values is supported for current Intel SKUs.
45 if (!r->membw.delay_linear) {
46 rdt_last_cmd_puts("No support for non-linear MB domains\n");
50 ret = kstrtoul(buf, 10, &bw);
52 rdt_last_cmd_printf("Non-decimal digit in MB value %s\n", buf);
56 if ((bw < r->membw.min_bw || bw > r->default_ctrl) &&
58 rdt_last_cmd_printf("MB value %ld out of range [%d,%d]\n", bw,
59 r->membw.min_bw, r->default_ctrl);
63 *data = roundup(bw, (unsigned long)r->membw.bw_gran);
67 int parse_bw(void *_buf, struct rdt_resource *r, struct rdt_domain *d)
72 if (d->have_new_ctrl) {
73 rdt_last_cmd_printf("duplicate domain %d\n", d->id);
77 if (!bw_validate(buf, &data, r))
80 d->have_new_ctrl = true;
86 * Check whether a cache bit mask is valid. The SDM says:
87 * Please note that all (and only) contiguous '1' combinations
88 * are allowed (e.g. FFFFH, 0FF0H, 003CH, etc.).
89 * Additionally Haswell requires at least two bits set.
91 static bool cbm_validate(char *buf, u32 *data, struct rdt_resource *r)
93 unsigned long first_bit, zero_bit, val;
94 unsigned int cbm_len = r->cache.cbm_len;
97 ret = kstrtoul(buf, 16, &val);
99 rdt_last_cmd_printf("non-hex character in mask %s\n", buf);
103 if (val == 0 || val > r->default_ctrl) {
104 rdt_last_cmd_puts("mask out of range\n");
108 first_bit = find_first_bit(&val, cbm_len);
109 zero_bit = find_next_zero_bit(&val, cbm_len, first_bit);
111 if (find_next_bit(&val, cbm_len, zero_bit) < cbm_len) {
112 rdt_last_cmd_printf("mask %lx has non-consecutive 1-bits\n", val);
116 if ((zero_bit - first_bit) < r->cache.min_cbm_bits) {
117 rdt_last_cmd_printf("Need at least %d bits in mask\n",
118 r->cache.min_cbm_bits);
126 struct rdt_cbm_parse_data {
127 struct rdtgroup *rdtgrp;
132 * Read one cache bit mask (hex). Check that it is valid for the current
135 int parse_cbm(void *_data, struct rdt_resource *r, struct rdt_domain *d)
137 struct rdt_cbm_parse_data *data = _data;
138 struct rdtgroup *rdtgrp = data->rdtgrp;
141 if (d->have_new_ctrl) {
142 rdt_last_cmd_printf("duplicate domain %d\n", d->id);
146 if (!cbm_validate(data->buf, &cbm_val, r))
150 * The CBM may not overlap with the CBM of another closid if
151 * either is exclusive.
153 if (rdtgroup_cbm_overlaps(r, d, cbm_val, rdtgrp->closid, true)) {
154 rdt_last_cmd_printf("overlaps with exclusive group\n");
158 if (rdtgroup_cbm_overlaps(r, d, cbm_val, rdtgrp->closid, false)) {
159 if (rdtgrp->mode == RDT_MODE_EXCLUSIVE) {
160 rdt_last_cmd_printf("overlaps with other group\n");
165 d->new_ctrl = cbm_val;
166 d->have_new_ctrl = true;
172 * For each domain in this resource we expect to find a series of:
174 * separated by ";". The "id" is in decimal, and must match one of
175 * the "id"s for this resource.
177 static int parse_line(char *line, struct rdt_resource *r,
178 struct rdtgroup *rdtgrp)
180 struct rdt_cbm_parse_data data;
181 char *dom = NULL, *id;
182 struct rdt_domain *d;
183 unsigned long dom_id;
186 if (!line || line[0] == '\0')
188 dom = strsep(&line, ";");
189 id = strsep(&dom, "=");
190 if (!dom || kstrtoul(id, 10, &dom_id)) {
191 rdt_last_cmd_puts("Missing '=' or non-numeric domain\n");
195 list_for_each_entry(d, &r->domains, list) {
196 if (d->id == dom_id) {
198 data.rdtgrp = rdtgrp;
199 if (r->parse_ctrlval(&data, r, d))
207 int update_domains(struct rdt_resource *r, int closid)
209 struct msr_param msr_param;
210 cpumask_var_t cpu_mask;
211 struct rdt_domain *d;
216 if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL))
219 msr_param.low = closid;
220 msr_param.high = msr_param.low + 1;
223 mba_sc = is_mba_sc(r);
224 list_for_each_entry(d, &r->domains, list) {
225 dc = !mba_sc ? d->ctrl_val : d->mbps_val;
226 if (d->have_new_ctrl && d->new_ctrl != dc[closid]) {
227 cpumask_set_cpu(cpumask_any(&d->cpu_mask), cpu_mask);
228 dc[closid] = d->new_ctrl;
233 * Avoid writing the control msr with control values when
234 * MBA software controller is enabled
236 if (cpumask_empty(cpu_mask) || mba_sc)
239 /* Update CBM on this cpu if it's in cpu_mask. */
240 if (cpumask_test_cpu(cpu, cpu_mask))
241 rdt_ctrl_update(&msr_param);
242 /* Update CBM on other cpus. */
243 smp_call_function_many(cpu_mask, rdt_ctrl_update, &msr_param, 1);
247 free_cpumask_var(cpu_mask);
252 static int rdtgroup_parse_resource(char *resname, char *tok,
253 struct rdtgroup *rdtgrp)
255 struct rdt_resource *r;
257 for_each_alloc_enabled_rdt_resource(r) {
258 if (!strcmp(resname, r->name) && rdtgrp->closid < r->num_closid)
259 return parse_line(tok, r, rdtgrp);
261 rdt_last_cmd_printf("unknown/unsupported resource name '%s'\n", resname);
265 ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of,
266 char *buf, size_t nbytes, loff_t off)
268 struct rdtgroup *rdtgrp;
269 struct rdt_domain *dom;
270 struct rdt_resource *r;
274 /* Valid input requires a trailing newline */
275 if (nbytes == 0 || buf[nbytes - 1] != '\n')
277 buf[nbytes - 1] = '\0';
279 rdtgrp = rdtgroup_kn_lock_live(of->kn);
281 rdtgroup_kn_unlock(of->kn);
284 rdt_last_cmd_clear();
287 * No changes to pseudo-locked region allowed. It has to be removed
288 * and re-created instead.
290 if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
292 rdt_last_cmd_puts("resource group is pseudo-locked\n");
296 for_each_alloc_enabled_rdt_resource(r) {
297 list_for_each_entry(dom, &r->domains, list)
298 dom->have_new_ctrl = false;
301 while ((tok = strsep(&buf, "\n")) != NULL) {
302 resname = strim(strsep(&tok, ":"));
304 rdt_last_cmd_puts("Missing ':'\n");
308 if (tok[0] == '\0') {
309 rdt_last_cmd_printf("Missing '%s' value\n", resname);
313 ret = rdtgroup_parse_resource(resname, tok, rdtgrp);
318 for_each_alloc_enabled_rdt_resource(r) {
319 ret = update_domains(r, rdtgrp->closid);
325 rdtgroup_kn_unlock(of->kn);
326 return ret ?: nbytes;
329 static void show_doms(struct seq_file *s, struct rdt_resource *r, int closid)
331 struct rdt_domain *dom;
335 seq_printf(s, "%*s:", max_name_width, r->name);
336 list_for_each_entry(dom, &r->domains, list) {
340 ctrl_val = (!is_mba_sc(r) ? dom->ctrl_val[closid] :
341 dom->mbps_val[closid]);
342 seq_printf(s, r->format_str, dom->id, max_data_width,
349 int rdtgroup_schemata_show(struct kernfs_open_file *of,
350 struct seq_file *s, void *v)
352 struct rdtgroup *rdtgrp;
353 struct rdt_resource *r;
357 rdtgrp = rdtgroup_kn_lock_live(of->kn);
359 closid = rdtgrp->closid;
360 for_each_alloc_enabled_rdt_resource(r) {
361 if (closid < r->num_closid)
362 show_doms(s, r, closid);
367 rdtgroup_kn_unlock(of->kn);
371 void mon_event_read(struct rmid_read *rr, struct rdt_domain *d,
372 struct rdtgroup *rdtgrp, int evtid, int first)
375 * setup the parameters to send to the IPI to read the data.
383 smp_call_function_any(&d->cpu_mask, mon_event_count, rr, 1);
386 int rdtgroup_mondata_show(struct seq_file *m, void *arg)
388 struct kernfs_open_file *of = m->private;
389 u32 resid, evtid, domid;
390 struct rdtgroup *rdtgrp;
391 struct rdt_resource *r;
392 union mon_data_bits md;
393 struct rdt_domain *d;
397 rdtgrp = rdtgroup_kn_lock_live(of->kn);
399 md.priv = of->kn->priv;
404 r = &rdt_resources_all[resid];
405 d = rdt_find_domain(r, domid, NULL);
411 mon_event_read(&rr, d, rdtgrp, evtid, false);
413 if (rr.val & RMID_VAL_ERROR)
414 seq_puts(m, "Error\n");
415 else if (rr.val & RMID_VAL_UNAVAIL)
416 seq_puts(m, "Unavailable\n");
418 seq_printf(m, "%llu\n", rr.val * r->mon_scale);
421 rdtgroup_kn_unlock(of->kn);