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