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  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 */
 30static 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
 60int parse_bw(struct rdt_parse_data *data, struct resctrl_schema *s,
 61	     struct rdt_domain *d)
 62{
 63	struct resctrl_staged_config *cfg;
 64	u32 closid = data->rdtgrp->closid;
 65	struct rdt_resource *r = s->res;
 66	unsigned long bw_val;
 67
 68	cfg = &d->staged_config[s->conf_type];
 69	if (cfg->have_new_ctrl) {
 70		rdt_last_cmd_printf("Duplicate domain %d\n", d->id);
 71		return -EINVAL;
 72	}
 73
 74	if (!bw_validate(data->buf, &bw_val, r))
 75		return -EINVAL;
 76
 77	if (is_mba_sc(r)) {
 78		d->mbps_val[closid] = bw_val;
 79		return 0;
 80	}
 81
 82	cfg->new_ctrl = bw_val;
 83	cfg->have_new_ctrl = true;
 84
 85	return 0;
 86}
 87
 88/*
 89 * Check whether a cache bit mask is valid.
 90 * For Intel the SDM says:
 91 *	Please note that all (and only) contiguous '1' combinations
 92 *	are allowed (e.g. FFFFH, 0FF0H, 003CH, etc.).
 93 * Additionally Haswell requires at least two bits set.
 94 * AMD allows non-contiguous bitmasks.
 95 */
 96static bool cbm_validate(char *buf, u32 *data, struct rdt_resource *r)
 97{
 98	unsigned long first_bit, zero_bit, val;
 99	unsigned int cbm_len = r->cache.cbm_len;
100	int ret;
101
102	ret = kstrtoul(buf, 16, &val);
103	if (ret) {
104		rdt_last_cmd_printf("Non-hex character in the mask %s\n", buf);
105		return false;
106	}
107
108	if ((r->cache.min_cbm_bits > 0 && val == 0) || val > r->default_ctrl) {
109		rdt_last_cmd_puts("Mask out of range\n");
110		return false;
111	}
112
113	first_bit = find_first_bit(&val, cbm_len);
114	zero_bit = find_next_zero_bit(&val, cbm_len, first_bit);
115
116	/* Are non-contiguous bitmaps allowed? */
117	if (!r->cache.arch_has_sparse_bitmaps &&
118	    (find_next_bit(&val, cbm_len, zero_bit) < cbm_len)) {
119		rdt_last_cmd_printf("The mask %lx has non-consecutive 1-bits\n", val);
120		return false;
121	}
122
123	if ((zero_bit - first_bit) < r->cache.min_cbm_bits) {
124		rdt_last_cmd_printf("Need at least %d bits in the mask\n",
125				    r->cache.min_cbm_bits);
126		return false;
127	}
128
129	*data = val;
130	return true;
131}
132
133/*
134 * Read one cache bit mask (hex). Check that it is valid for the current
135 * resource type.
136 */
137int parse_cbm(struct rdt_parse_data *data, struct resctrl_schema *s,
138	      struct rdt_domain *d)
139{
140	struct rdtgroup *rdtgrp = data->rdtgrp;
141	struct resctrl_staged_config *cfg;
142	struct rdt_resource *r = s->res;
143	u32 cbm_val;
144
145	cfg = &d->staged_config[s->conf_type];
146	if (cfg->have_new_ctrl) {
147		rdt_last_cmd_printf("Duplicate domain %d\n", d->id);
148		return -EINVAL;
149	}
150
151	/*
152	 * Cannot set up more than one pseudo-locked region in a cache
153	 * hierarchy.
154	 */
155	if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP &&
156	    rdtgroup_pseudo_locked_in_hierarchy(d)) {
157		rdt_last_cmd_puts("Pseudo-locked region in hierarchy\n");
158		return -EINVAL;
159	}
160
161	if (!cbm_validate(data->buf, &cbm_val, r))
162		return -EINVAL;
163
164	if ((rdtgrp->mode == RDT_MODE_EXCLUSIVE ||
165	     rdtgrp->mode == RDT_MODE_SHAREABLE) &&
166	    rdtgroup_cbm_overlaps_pseudo_locked(d, cbm_val)) {
167		rdt_last_cmd_puts("CBM overlaps with pseudo-locked region\n");
168		return -EINVAL;
169	}
170
171	/*
172	 * The CBM may not overlap with the CBM of another closid if
173	 * either is exclusive.
174	 */
175	if (rdtgroup_cbm_overlaps(s, d, cbm_val, rdtgrp->closid, true)) {
176		rdt_last_cmd_puts("Overlaps with exclusive group\n");
177		return -EINVAL;
178	}
179
180	if (rdtgroup_cbm_overlaps(s, d, cbm_val, rdtgrp->closid, false)) {
181		if (rdtgrp->mode == RDT_MODE_EXCLUSIVE ||
182		    rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
183			rdt_last_cmd_puts("Overlaps with other group\n");
184			return -EINVAL;
185		}
186	}
187
188	cfg->new_ctrl = cbm_val;
189	cfg->have_new_ctrl = true;
190
191	return 0;
192}
193
194/*
195 * For each domain in this resource we expect to find a series of:
196 *	id=mask
197 * separated by ";". The "id" is in decimal, and must match one of
198 * the "id"s for this resource.
199 */
200static int parse_line(char *line, struct resctrl_schema *s,
201		      struct rdtgroup *rdtgrp)
202{
203	enum resctrl_conf_type t = s->conf_type;
204	struct resctrl_staged_config *cfg;
205	struct rdt_resource *r = s->res;
206	struct rdt_parse_data data;
207	char *dom = NULL, *id;
208	struct rdt_domain *d;
209	unsigned long dom_id;
210
211	if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP &&
212	    r->rid == RDT_RESOURCE_MBA) {
213		rdt_last_cmd_puts("Cannot pseudo-lock MBA resource\n");
214		return -EINVAL;
215	}
216
217next:
218	if (!line || line[0] == '\0')
219		return 0;
220	dom = strsep(&line, ";");
221	id = strsep(&dom, "=");
222	if (!dom || kstrtoul(id, 10, &dom_id)) {
223		rdt_last_cmd_puts("Missing '=' or non-numeric domain\n");
224		return -EINVAL;
225	}
226	dom = strim(dom);
227	list_for_each_entry(d, &r->domains, list) {
228		if (d->id == dom_id) {
229			data.buf = dom;
230			data.rdtgrp = rdtgrp;
231			if (r->parse_ctrlval(&data, s, d))
232				return -EINVAL;
233			if (rdtgrp->mode ==  RDT_MODE_PSEUDO_LOCKSETUP) {
234				cfg = &d->staged_config[t];
235				/*
236				 * In pseudo-locking setup mode and just
237				 * parsed a valid CBM that should be
238				 * pseudo-locked. Only one locked region per
239				 * resource group and domain so just do
240				 * the required initialization for single
241				 * region and return.
242				 */
243				rdtgrp->plr->s = s;
244				rdtgrp->plr->d = d;
245				rdtgrp->plr->cbm = cfg->new_ctrl;
246				d->plr = rdtgrp->plr;
247				return 0;
248			}
249			goto next;
250		}
251	}
252	return -EINVAL;
253}
254
255static u32 get_config_index(u32 closid, enum resctrl_conf_type type)
256{
257	switch (type) {
258	default:
259	case CDP_NONE:
260		return closid;
261	case CDP_CODE:
262		return closid * 2 + 1;
263	case CDP_DATA:
264		return closid * 2;
265	}
266}
267
268static bool apply_config(struct rdt_hw_domain *hw_dom,
269			 struct resctrl_staged_config *cfg, u32 idx,
270			 cpumask_var_t cpu_mask)
271{
272	struct rdt_domain *dom = &hw_dom->d_resctrl;
273
274	if (cfg->new_ctrl != hw_dom->ctrl_val[idx]) {
275		cpumask_set_cpu(cpumask_any(&dom->cpu_mask), cpu_mask);
276		hw_dom->ctrl_val[idx] = cfg->new_ctrl;
277
278		return true;
279	}
280
281	return false;
282}
283
284int resctrl_arch_update_one(struct rdt_resource *r, struct rdt_domain *d,
285			    u32 closid, enum resctrl_conf_type t, u32 cfg_val)
286{
287	struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
288	struct rdt_hw_domain *hw_dom = resctrl_to_arch_dom(d);
289	u32 idx = get_config_index(closid, t);
290	struct msr_param msr_param;
291
292	if (!cpumask_test_cpu(smp_processor_id(), &d->cpu_mask))
293		return -EINVAL;
294
295	hw_dom->ctrl_val[idx] = cfg_val;
296
297	msr_param.res = r;
298	msr_param.low = idx;
299	msr_param.high = idx + 1;
300	hw_res->msr_update(d, &msr_param, r);
301
302	return 0;
303}
304
305int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid)
306{
307	struct resctrl_staged_config *cfg;
308	struct rdt_hw_domain *hw_dom;
309	struct msr_param msr_param;
310	enum resctrl_conf_type t;
311	cpumask_var_t cpu_mask;
312	struct rdt_domain *d;
313	int cpu;
314	u32 idx;
315
316	if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL))
317		return -ENOMEM;
318
319	msr_param.res = NULL;
320	list_for_each_entry(d, &r->domains, list) {
321		hw_dom = resctrl_to_arch_dom(d);
322		for (t = 0; t < CDP_NUM_TYPES; t++) {
323			cfg = &hw_dom->d_resctrl.staged_config[t];
324			if (!cfg->have_new_ctrl)
325				continue;
326
327			idx = get_config_index(closid, t);
328			if (!apply_config(hw_dom, cfg, idx, cpu_mask))
329				continue;
330
331			if (!msr_param.res) {
332				msr_param.low = idx;
333				msr_param.high = msr_param.low + 1;
334				msr_param.res = r;
335			} else {
336				msr_param.low = min(msr_param.low, idx);
337				msr_param.high = max(msr_param.high, idx + 1);
338			}
339		}
340	}
341
342	if (cpumask_empty(cpu_mask))
343		goto done;
344	cpu = get_cpu();
345	/* Update resource control msr on this CPU if it's in cpu_mask. */
346	if (cpumask_test_cpu(cpu, cpu_mask))
347		rdt_ctrl_update(&msr_param);
348	/* Update resource control msr on other CPUs. */
349	smp_call_function_many(cpu_mask, rdt_ctrl_update, &msr_param, 1);
350	put_cpu();
351
352done:
353	free_cpumask_var(cpu_mask);
354
355	return 0;
356}
357
358static int rdtgroup_parse_resource(char *resname, char *tok,
359				   struct rdtgroup *rdtgrp)
360{
361	struct resctrl_schema *s;
362
363	list_for_each_entry(s, &resctrl_schema_all, list) {
364		if (!strcmp(resname, s->name) && rdtgrp->closid < s->num_closid)
365			return parse_line(tok, s, rdtgrp);
366	}
367	rdt_last_cmd_printf("Unknown or unsupported resource name '%s'\n", resname);
368	return -EINVAL;
369}
370
371ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of,
372				char *buf, size_t nbytes, loff_t off)
373{
374	struct resctrl_schema *s;
375	struct rdtgroup *rdtgrp;
376	struct rdt_domain *dom;
377	struct rdt_resource *r;
378	char *tok, *resname;
379	int ret = 0;
380
381	/* Valid input requires a trailing newline */
382	if (nbytes == 0 || buf[nbytes - 1] != '\n')
383		return -EINVAL;
384	buf[nbytes - 1] = '\0';
385
386	cpus_read_lock();
387	rdtgrp = rdtgroup_kn_lock_live(of->kn);
388	if (!rdtgrp) {
389		rdtgroup_kn_unlock(of->kn);
390		cpus_read_unlock();
391		return -ENOENT;
392	}
393	rdt_last_cmd_clear();
394
395	/*
396	 * No changes to pseudo-locked region allowed. It has to be removed
397	 * and re-created instead.
398	 */
399	if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
400		ret = -EINVAL;
401		rdt_last_cmd_puts("Resource group is pseudo-locked\n");
402		goto out;
403	}
404
405	list_for_each_entry(s, &resctrl_schema_all, list) {
406		list_for_each_entry(dom, &s->res->domains, list)
407			memset(dom->staged_config, 0, sizeof(dom->staged_config));
408	}
409
410	while ((tok = strsep(&buf, "\n")) != NULL) {
411		resname = strim(strsep(&tok, ":"));
412		if (!tok) {
413			rdt_last_cmd_puts("Missing ':'\n");
414			ret = -EINVAL;
415			goto out;
416		}
417		if (tok[0] == '\0') {
418			rdt_last_cmd_printf("Missing '%s' value\n", resname);
419			ret = -EINVAL;
420			goto out;
421		}
422		ret = rdtgroup_parse_resource(resname, tok, rdtgrp);
423		if (ret)
424			goto out;
425	}
426
427	list_for_each_entry(s, &resctrl_schema_all, list) {
428		r = s->res;
429
430		/*
431		 * Writes to mba_sc resources update the software controller,
432		 * not the control MSR.
433		 */
434		if (is_mba_sc(r))
435			continue;
436
437		ret = resctrl_arch_update_domains(r, rdtgrp->closid);
438		if (ret)
439			goto out;
440	}
441
442	if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
443		/*
444		 * If pseudo-locking fails we keep the resource group in
445		 * mode RDT_MODE_PSEUDO_LOCKSETUP with its class of service
446		 * active and updated for just the domain the pseudo-locked
447		 * region was requested for.
448		 */
449		ret = rdtgroup_pseudo_lock_create(rdtgrp);
450	}
451
452out:
453	rdtgroup_kn_unlock(of->kn);
454	cpus_read_unlock();
455	return ret ?: nbytes;
456}
457
458u32 resctrl_arch_get_config(struct rdt_resource *r, struct rdt_domain *d,
459			    u32 closid, enum resctrl_conf_type type)
460{
461	struct rdt_hw_domain *hw_dom = resctrl_to_arch_dom(d);
462	u32 idx = get_config_index(closid, type);
463
464	return hw_dom->ctrl_val[idx];
465}
466
467static void show_doms(struct seq_file *s, struct resctrl_schema *schema, int closid)
468{
469	struct rdt_resource *r = schema->res;
470	struct rdt_domain *dom;
471	bool sep = false;
472	u32 ctrl_val;
473
474	seq_printf(s, "%*s:", max_name_width, schema->name);
475	list_for_each_entry(dom, &r->domains, list) {
476		if (sep)
477			seq_puts(s, ";");
478
479		if (is_mba_sc(r))
480			ctrl_val = dom->mbps_val[closid];
481		else
482			ctrl_val = resctrl_arch_get_config(r, dom, closid,
483							   schema->conf_type);
484
485		seq_printf(s, r->format_str, dom->id, max_data_width,
486			   ctrl_val);
487		sep = true;
488	}
489	seq_puts(s, "\n");
490}
491
492int rdtgroup_schemata_show(struct kernfs_open_file *of,
493			   struct seq_file *s, void *v)
494{
495	struct resctrl_schema *schema;
496	struct rdtgroup *rdtgrp;
497	int ret = 0;
498	u32 closid;
499
500	rdtgrp = rdtgroup_kn_lock_live(of->kn);
501	if (rdtgrp) {
502		if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
503			list_for_each_entry(schema, &resctrl_schema_all, list) {
504				seq_printf(s, "%s:uninitialized\n", schema->name);
505			}
506		} else if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
507			if (!rdtgrp->plr->d) {
508				rdt_last_cmd_clear();
509				rdt_last_cmd_puts("Cache domain offline\n");
510				ret = -ENODEV;
511			} else {
512				seq_printf(s, "%s:%d=%x\n",
513					   rdtgrp->plr->s->res->name,
514					   rdtgrp->plr->d->id,
515					   rdtgrp->plr->cbm);
516			}
517		} else {
518			closid = rdtgrp->closid;
519			list_for_each_entry(schema, &resctrl_schema_all, list) {
520				if (closid < schema->num_closid)
521					show_doms(s, schema, closid);
522			}
523		}
524	} else {
525		ret = -ENOENT;
526	}
527	rdtgroup_kn_unlock(of->kn);
528	return ret;
529}
530
531void mon_event_read(struct rmid_read *rr, struct rdt_resource *r,
532		    struct rdt_domain *d, struct rdtgroup *rdtgrp,
533		    int evtid, int first)
534{
535	/*
536	 * setup the parameters to send to the IPI to read the data.
537	 */
538	rr->rgrp = rdtgrp;
539	rr->evtid = evtid;
540	rr->r = r;
541	rr->d = d;
542	rr->val = 0;
543	rr->first = first;
544
545	smp_call_function_any(&d->cpu_mask, mon_event_count, rr, 1);
546}
547
548int rdtgroup_mondata_show(struct seq_file *m, void *arg)
549{
550	struct kernfs_open_file *of = m->private;
551	u32 resid, evtid, domid;
552	struct rdtgroup *rdtgrp;
553	struct rdt_resource *r;
554	union mon_data_bits md;
555	struct rdt_domain *d;
556	struct rmid_read rr;
557	int ret = 0;
558
559	rdtgrp = rdtgroup_kn_lock_live(of->kn);
560	if (!rdtgrp) {
561		ret = -ENOENT;
562		goto out;
563	}
564
565	md.priv = of->kn->priv;
566	resid = md.u.rid;
567	domid = md.u.domid;
568	evtid = md.u.evtid;
569
570	r = &rdt_resources_all[resid].r_resctrl;
571	d = rdt_find_domain(r, domid, NULL);
572	if (IS_ERR_OR_NULL(d)) {
573		ret = -ENOENT;
574		goto out;
575	}
576
577	mon_event_read(&rr, r, d, rdtgrp, evtid, false);
578
579	if (rr.err == -EIO)
580		seq_puts(m, "Error\n");
581	else if (rr.err == -EINVAL)
582		seq_puts(m, "Unavailable\n");
583	else
584		seq_printf(m, "%llu\n", rr.val);
585
586out:
587	rdtgroup_kn_unlock(of->kn);
588	return ret;
589}