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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * User interface for Resource Alloction in Resource Director Technology(RDT)
4 *
5 * Copyright (C) 2016 Intel Corporation
6 *
7 * Author: Fenghua Yu <fenghua.yu@intel.com>
8 *
9 * More information about RDT be found in the Intel (R) x86 Architecture
10 * Software Developer Manual.
11 */
12
13#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14
15#include <linux/cacheinfo.h>
16#include <linux/cpu.h>
17#include <linux/debugfs.h>
18#include <linux/fs.h>
19#include <linux/fs_parser.h>
20#include <linux/sysfs.h>
21#include <linux/kernfs.h>
22#include <linux/seq_buf.h>
23#include <linux/seq_file.h>
24#include <linux/sched/signal.h>
25#include <linux/sched/task.h>
26#include <linux/slab.h>
27#include <linux/task_work.h>
28#include <linux/user_namespace.h>
29
30#include <uapi/linux/magic.h>
31
32#include <asm/resctrl_sched.h>
33#include "internal.h"
34
35DEFINE_STATIC_KEY_FALSE(rdt_enable_key);
36DEFINE_STATIC_KEY_FALSE(rdt_mon_enable_key);
37DEFINE_STATIC_KEY_FALSE(rdt_alloc_enable_key);
38static struct kernfs_root *rdt_root;
39struct rdtgroup rdtgroup_default;
40LIST_HEAD(rdt_all_groups);
41
42/* Kernel fs node for "info" directory under root */
43static struct kernfs_node *kn_info;
44
45/* Kernel fs node for "mon_groups" directory under root */
46static struct kernfs_node *kn_mongrp;
47
48/* Kernel fs node for "mon_data" directory under root */
49static struct kernfs_node *kn_mondata;
50
51static struct seq_buf last_cmd_status;
52static char last_cmd_status_buf[512];
53
54struct dentry *debugfs_resctrl;
55
56void rdt_last_cmd_clear(void)
57{
58 lockdep_assert_held(&rdtgroup_mutex);
59 seq_buf_clear(&last_cmd_status);
60}
61
62void rdt_last_cmd_puts(const char *s)
63{
64 lockdep_assert_held(&rdtgroup_mutex);
65 seq_buf_puts(&last_cmd_status, s);
66}
67
68void rdt_last_cmd_printf(const char *fmt, ...)
69{
70 va_list ap;
71
72 va_start(ap, fmt);
73 lockdep_assert_held(&rdtgroup_mutex);
74 seq_buf_vprintf(&last_cmd_status, fmt, ap);
75 va_end(ap);
76}
77
78/*
79 * Trivial allocator for CLOSIDs. Since h/w only supports a small number,
80 * we can keep a bitmap of free CLOSIDs in a single integer.
81 *
82 * Using a global CLOSID across all resources has some advantages and
83 * some drawbacks:
84 * + We can simply set "current->closid" to assign a task to a resource
85 * group.
86 * + Context switch code can avoid extra memory references deciding which
87 * CLOSID to load into the PQR_ASSOC MSR
88 * - We give up some options in configuring resource groups across multi-socket
89 * systems.
90 * - Our choices on how to configure each resource become progressively more
91 * limited as the number of resources grows.
92 */
93static int closid_free_map;
94static int closid_free_map_len;
95
96int closids_supported(void)
97{
98 return closid_free_map_len;
99}
100
101static void closid_init(void)
102{
103 struct rdt_resource *r;
104 int rdt_min_closid = 32;
105
106 /* Compute rdt_min_closid across all resources */
107 for_each_alloc_enabled_rdt_resource(r)
108 rdt_min_closid = min(rdt_min_closid, r->num_closid);
109
110 closid_free_map = BIT_MASK(rdt_min_closid) - 1;
111
112 /* CLOSID 0 is always reserved for the default group */
113 closid_free_map &= ~1;
114 closid_free_map_len = rdt_min_closid;
115}
116
117static int closid_alloc(void)
118{
119 u32 closid = ffs(closid_free_map);
120
121 if (closid == 0)
122 return -ENOSPC;
123 closid--;
124 closid_free_map &= ~(1 << closid);
125
126 return closid;
127}
128
129void closid_free(int closid)
130{
131 closid_free_map |= 1 << closid;
132}
133
134/**
135 * closid_allocated - test if provided closid is in use
136 * @closid: closid to be tested
137 *
138 * Return: true if @closid is currently associated with a resource group,
139 * false if @closid is free
140 */
141static bool closid_allocated(unsigned int closid)
142{
143 return (closid_free_map & (1 << closid)) == 0;
144}
145
146/**
147 * rdtgroup_mode_by_closid - Return mode of resource group with closid
148 * @closid: closid if the resource group
149 *
150 * Each resource group is associated with a @closid. Here the mode
151 * of a resource group can be queried by searching for it using its closid.
152 *
153 * Return: mode as &enum rdtgrp_mode of resource group with closid @closid
154 */
155enum rdtgrp_mode rdtgroup_mode_by_closid(int closid)
156{
157 struct rdtgroup *rdtgrp;
158
159 list_for_each_entry(rdtgrp, &rdt_all_groups, rdtgroup_list) {
160 if (rdtgrp->closid == closid)
161 return rdtgrp->mode;
162 }
163
164 return RDT_NUM_MODES;
165}
166
167static const char * const rdt_mode_str[] = {
168 [RDT_MODE_SHAREABLE] = "shareable",
169 [RDT_MODE_EXCLUSIVE] = "exclusive",
170 [RDT_MODE_PSEUDO_LOCKSETUP] = "pseudo-locksetup",
171 [RDT_MODE_PSEUDO_LOCKED] = "pseudo-locked",
172};
173
174/**
175 * rdtgroup_mode_str - Return the string representation of mode
176 * @mode: the resource group mode as &enum rdtgroup_mode
177 *
178 * Return: string representation of valid mode, "unknown" otherwise
179 */
180static const char *rdtgroup_mode_str(enum rdtgrp_mode mode)
181{
182 if (mode < RDT_MODE_SHAREABLE || mode >= RDT_NUM_MODES)
183 return "unknown";
184
185 return rdt_mode_str[mode];
186}
187
188/* set uid and gid of rdtgroup dirs and files to that of the creator */
189static int rdtgroup_kn_set_ugid(struct kernfs_node *kn)
190{
191 struct iattr iattr = { .ia_valid = ATTR_UID | ATTR_GID,
192 .ia_uid = current_fsuid(),
193 .ia_gid = current_fsgid(), };
194
195 if (uid_eq(iattr.ia_uid, GLOBAL_ROOT_UID) &&
196 gid_eq(iattr.ia_gid, GLOBAL_ROOT_GID))
197 return 0;
198
199 return kernfs_setattr(kn, &iattr);
200}
201
202static int rdtgroup_add_file(struct kernfs_node *parent_kn, struct rftype *rft)
203{
204 struct kernfs_node *kn;
205 int ret;
206
207 kn = __kernfs_create_file(parent_kn, rft->name, rft->mode,
208 GLOBAL_ROOT_UID, GLOBAL_ROOT_GID,
209 0, rft->kf_ops, rft, NULL, NULL);
210 if (IS_ERR(kn))
211 return PTR_ERR(kn);
212
213 ret = rdtgroup_kn_set_ugid(kn);
214 if (ret) {
215 kernfs_remove(kn);
216 return ret;
217 }
218
219 return 0;
220}
221
222static int rdtgroup_seqfile_show(struct seq_file *m, void *arg)
223{
224 struct kernfs_open_file *of = m->private;
225 struct rftype *rft = of->kn->priv;
226
227 if (rft->seq_show)
228 return rft->seq_show(of, m, arg);
229 return 0;
230}
231
232static ssize_t rdtgroup_file_write(struct kernfs_open_file *of, char *buf,
233 size_t nbytes, loff_t off)
234{
235 struct rftype *rft = of->kn->priv;
236
237 if (rft->write)
238 return rft->write(of, buf, nbytes, off);
239
240 return -EINVAL;
241}
242
243static struct kernfs_ops rdtgroup_kf_single_ops = {
244 .atomic_write_len = PAGE_SIZE,
245 .write = rdtgroup_file_write,
246 .seq_show = rdtgroup_seqfile_show,
247};
248
249static struct kernfs_ops kf_mondata_ops = {
250 .atomic_write_len = PAGE_SIZE,
251 .seq_show = rdtgroup_mondata_show,
252};
253
254static bool is_cpu_list(struct kernfs_open_file *of)
255{
256 struct rftype *rft = of->kn->priv;
257
258 return rft->flags & RFTYPE_FLAGS_CPUS_LIST;
259}
260
261static int rdtgroup_cpus_show(struct kernfs_open_file *of,
262 struct seq_file *s, void *v)
263{
264 struct rdtgroup *rdtgrp;
265 struct cpumask *mask;
266 int ret = 0;
267
268 rdtgrp = rdtgroup_kn_lock_live(of->kn);
269
270 if (rdtgrp) {
271 if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
272 if (!rdtgrp->plr->d) {
273 rdt_last_cmd_clear();
274 rdt_last_cmd_puts("Cache domain offline\n");
275 ret = -ENODEV;
276 } else {
277 mask = &rdtgrp->plr->d->cpu_mask;
278 seq_printf(s, is_cpu_list(of) ?
279 "%*pbl\n" : "%*pb\n",
280 cpumask_pr_args(mask));
281 }
282 } else {
283 seq_printf(s, is_cpu_list(of) ? "%*pbl\n" : "%*pb\n",
284 cpumask_pr_args(&rdtgrp->cpu_mask));
285 }
286 } else {
287 ret = -ENOENT;
288 }
289 rdtgroup_kn_unlock(of->kn);
290
291 return ret;
292}
293
294/*
295 * This is safe against resctrl_sched_in() called from __switch_to()
296 * because __switch_to() is executed with interrupts disabled. A local call
297 * from update_closid_rmid() is proteced against __switch_to() because
298 * preemption is disabled.
299 */
300static void update_cpu_closid_rmid(void *info)
301{
302 struct rdtgroup *r = info;
303
304 if (r) {
305 this_cpu_write(pqr_state.default_closid, r->closid);
306 this_cpu_write(pqr_state.default_rmid, r->mon.rmid);
307 }
308
309 /*
310 * We cannot unconditionally write the MSR because the current
311 * executing task might have its own closid selected. Just reuse
312 * the context switch code.
313 */
314 resctrl_sched_in();
315}
316
317/*
318 * Update the PGR_ASSOC MSR on all cpus in @cpu_mask,
319 *
320 * Per task closids/rmids must have been set up before calling this function.
321 */
322static void
323update_closid_rmid(const struct cpumask *cpu_mask, struct rdtgroup *r)
324{
325 int cpu = get_cpu();
326
327 if (cpumask_test_cpu(cpu, cpu_mask))
328 update_cpu_closid_rmid(r);
329 smp_call_function_many(cpu_mask, update_cpu_closid_rmid, r, 1);
330 put_cpu();
331}
332
333static int cpus_mon_write(struct rdtgroup *rdtgrp, cpumask_var_t newmask,
334 cpumask_var_t tmpmask)
335{
336 struct rdtgroup *prgrp = rdtgrp->mon.parent, *crgrp;
337 struct list_head *head;
338
339 /* Check whether cpus belong to parent ctrl group */
340 cpumask_andnot(tmpmask, newmask, &prgrp->cpu_mask);
341 if (cpumask_weight(tmpmask)) {
342 rdt_last_cmd_puts("Can only add CPUs to mongroup that belong to parent\n");
343 return -EINVAL;
344 }
345
346 /* Check whether cpus are dropped from this group */
347 cpumask_andnot(tmpmask, &rdtgrp->cpu_mask, newmask);
348 if (cpumask_weight(tmpmask)) {
349 /* Give any dropped cpus to parent rdtgroup */
350 cpumask_or(&prgrp->cpu_mask, &prgrp->cpu_mask, tmpmask);
351 update_closid_rmid(tmpmask, prgrp);
352 }
353
354 /*
355 * If we added cpus, remove them from previous group that owned them
356 * and update per-cpu rmid
357 */
358 cpumask_andnot(tmpmask, newmask, &rdtgrp->cpu_mask);
359 if (cpumask_weight(tmpmask)) {
360 head = &prgrp->mon.crdtgrp_list;
361 list_for_each_entry(crgrp, head, mon.crdtgrp_list) {
362 if (crgrp == rdtgrp)
363 continue;
364 cpumask_andnot(&crgrp->cpu_mask, &crgrp->cpu_mask,
365 tmpmask);
366 }
367 update_closid_rmid(tmpmask, rdtgrp);
368 }
369
370 /* Done pushing/pulling - update this group with new mask */
371 cpumask_copy(&rdtgrp->cpu_mask, newmask);
372
373 return 0;
374}
375
376static void cpumask_rdtgrp_clear(struct rdtgroup *r, struct cpumask *m)
377{
378 struct rdtgroup *crgrp;
379
380 cpumask_andnot(&r->cpu_mask, &r->cpu_mask, m);
381 /* update the child mon group masks as well*/
382 list_for_each_entry(crgrp, &r->mon.crdtgrp_list, mon.crdtgrp_list)
383 cpumask_and(&crgrp->cpu_mask, &r->cpu_mask, &crgrp->cpu_mask);
384}
385
386static int cpus_ctrl_write(struct rdtgroup *rdtgrp, cpumask_var_t newmask,
387 cpumask_var_t tmpmask, cpumask_var_t tmpmask1)
388{
389 struct rdtgroup *r, *crgrp;
390 struct list_head *head;
391
392 /* Check whether cpus are dropped from this group */
393 cpumask_andnot(tmpmask, &rdtgrp->cpu_mask, newmask);
394 if (cpumask_weight(tmpmask)) {
395 /* Can't drop from default group */
396 if (rdtgrp == &rdtgroup_default) {
397 rdt_last_cmd_puts("Can't drop CPUs from default group\n");
398 return -EINVAL;
399 }
400
401 /* Give any dropped cpus to rdtgroup_default */
402 cpumask_or(&rdtgroup_default.cpu_mask,
403 &rdtgroup_default.cpu_mask, tmpmask);
404 update_closid_rmid(tmpmask, &rdtgroup_default);
405 }
406
407 /*
408 * If we added cpus, remove them from previous group and
409 * the prev group's child groups that owned them
410 * and update per-cpu closid/rmid.
411 */
412 cpumask_andnot(tmpmask, newmask, &rdtgrp->cpu_mask);
413 if (cpumask_weight(tmpmask)) {
414 list_for_each_entry(r, &rdt_all_groups, rdtgroup_list) {
415 if (r == rdtgrp)
416 continue;
417 cpumask_and(tmpmask1, &r->cpu_mask, tmpmask);
418 if (cpumask_weight(tmpmask1))
419 cpumask_rdtgrp_clear(r, tmpmask1);
420 }
421 update_closid_rmid(tmpmask, rdtgrp);
422 }
423
424 /* Done pushing/pulling - update this group with new mask */
425 cpumask_copy(&rdtgrp->cpu_mask, newmask);
426
427 /*
428 * Clear child mon group masks since there is a new parent mask
429 * now and update the rmid for the cpus the child lost.
430 */
431 head = &rdtgrp->mon.crdtgrp_list;
432 list_for_each_entry(crgrp, head, mon.crdtgrp_list) {
433 cpumask_and(tmpmask, &rdtgrp->cpu_mask, &crgrp->cpu_mask);
434 update_closid_rmid(tmpmask, rdtgrp);
435 cpumask_clear(&crgrp->cpu_mask);
436 }
437
438 return 0;
439}
440
441static ssize_t rdtgroup_cpus_write(struct kernfs_open_file *of,
442 char *buf, size_t nbytes, loff_t off)
443{
444 cpumask_var_t tmpmask, newmask, tmpmask1;
445 struct rdtgroup *rdtgrp;
446 int ret;
447
448 if (!buf)
449 return -EINVAL;
450
451 if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL))
452 return -ENOMEM;
453 if (!zalloc_cpumask_var(&newmask, GFP_KERNEL)) {
454 free_cpumask_var(tmpmask);
455 return -ENOMEM;
456 }
457 if (!zalloc_cpumask_var(&tmpmask1, GFP_KERNEL)) {
458 free_cpumask_var(tmpmask);
459 free_cpumask_var(newmask);
460 return -ENOMEM;
461 }
462
463 rdtgrp = rdtgroup_kn_lock_live(of->kn);
464 if (!rdtgrp) {
465 ret = -ENOENT;
466 goto unlock;
467 }
468
469 if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED ||
470 rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
471 ret = -EINVAL;
472 rdt_last_cmd_puts("Pseudo-locking in progress\n");
473 goto unlock;
474 }
475
476 if (is_cpu_list(of))
477 ret = cpulist_parse(buf, newmask);
478 else
479 ret = cpumask_parse(buf, newmask);
480
481 if (ret) {
482 rdt_last_cmd_puts("Bad CPU list/mask\n");
483 goto unlock;
484 }
485
486 /* check that user didn't specify any offline cpus */
487 cpumask_andnot(tmpmask, newmask, cpu_online_mask);
488 if (cpumask_weight(tmpmask)) {
489 ret = -EINVAL;
490 rdt_last_cmd_puts("Can only assign online CPUs\n");
491 goto unlock;
492 }
493
494 if (rdtgrp->type == RDTCTRL_GROUP)
495 ret = cpus_ctrl_write(rdtgrp, newmask, tmpmask, tmpmask1);
496 else if (rdtgrp->type == RDTMON_GROUP)
497 ret = cpus_mon_write(rdtgrp, newmask, tmpmask);
498 else
499 ret = -EINVAL;
500
501unlock:
502 rdtgroup_kn_unlock(of->kn);
503 free_cpumask_var(tmpmask);
504 free_cpumask_var(newmask);
505 free_cpumask_var(tmpmask1);
506
507 return ret ?: nbytes;
508}
509
510struct task_move_callback {
511 struct callback_head work;
512 struct rdtgroup *rdtgrp;
513};
514
515static void move_myself(struct callback_head *head)
516{
517 struct task_move_callback *callback;
518 struct rdtgroup *rdtgrp;
519
520 callback = container_of(head, struct task_move_callback, work);
521 rdtgrp = callback->rdtgrp;
522
523 /*
524 * If resource group was deleted before this task work callback
525 * was invoked, then assign the task to root group and free the
526 * resource group.
527 */
528 if (atomic_dec_and_test(&rdtgrp->waitcount) &&
529 (rdtgrp->flags & RDT_DELETED)) {
530 current->closid = 0;
531 current->rmid = 0;
532 kfree(rdtgrp);
533 }
534
535 preempt_disable();
536 /* update PQR_ASSOC MSR to make resource group go into effect */
537 resctrl_sched_in();
538 preempt_enable();
539
540 kfree(callback);
541}
542
543static int __rdtgroup_move_task(struct task_struct *tsk,
544 struct rdtgroup *rdtgrp)
545{
546 struct task_move_callback *callback;
547 int ret;
548
549 callback = kzalloc(sizeof(*callback), GFP_KERNEL);
550 if (!callback)
551 return -ENOMEM;
552 callback->work.func = move_myself;
553 callback->rdtgrp = rdtgrp;
554
555 /*
556 * Take a refcount, so rdtgrp cannot be freed before the
557 * callback has been invoked.
558 */
559 atomic_inc(&rdtgrp->waitcount);
560 ret = task_work_add(tsk, &callback->work, true);
561 if (ret) {
562 /*
563 * Task is exiting. Drop the refcount and free the callback.
564 * No need to check the refcount as the group cannot be
565 * deleted before the write function unlocks rdtgroup_mutex.
566 */
567 atomic_dec(&rdtgrp->waitcount);
568 kfree(callback);
569 rdt_last_cmd_puts("Task exited\n");
570 } else {
571 /*
572 * For ctrl_mon groups move both closid and rmid.
573 * For monitor groups, can move the tasks only from
574 * their parent CTRL group.
575 */
576 if (rdtgrp->type == RDTCTRL_GROUP) {
577 tsk->closid = rdtgrp->closid;
578 tsk->rmid = rdtgrp->mon.rmid;
579 } else if (rdtgrp->type == RDTMON_GROUP) {
580 if (rdtgrp->mon.parent->closid == tsk->closid) {
581 tsk->rmid = rdtgrp->mon.rmid;
582 } else {
583 rdt_last_cmd_puts("Can't move task to different control group\n");
584 ret = -EINVAL;
585 }
586 }
587 }
588 return ret;
589}
590
591/**
592 * rdtgroup_tasks_assigned - Test if tasks have been assigned to resource group
593 * @r: Resource group
594 *
595 * Return: 1 if tasks have been assigned to @r, 0 otherwise
596 */
597int rdtgroup_tasks_assigned(struct rdtgroup *r)
598{
599 struct task_struct *p, *t;
600 int ret = 0;
601
602 lockdep_assert_held(&rdtgroup_mutex);
603
604 rcu_read_lock();
605 for_each_process_thread(p, t) {
606 if ((r->type == RDTCTRL_GROUP && t->closid == r->closid) ||
607 (r->type == RDTMON_GROUP && t->rmid == r->mon.rmid)) {
608 ret = 1;
609 break;
610 }
611 }
612 rcu_read_unlock();
613
614 return ret;
615}
616
617static int rdtgroup_task_write_permission(struct task_struct *task,
618 struct kernfs_open_file *of)
619{
620 const struct cred *tcred = get_task_cred(task);
621 const struct cred *cred = current_cred();
622 int ret = 0;
623
624 /*
625 * Even if we're attaching all tasks in the thread group, we only
626 * need to check permissions on one of them.
627 */
628 if (!uid_eq(cred->euid, GLOBAL_ROOT_UID) &&
629 !uid_eq(cred->euid, tcred->uid) &&
630 !uid_eq(cred->euid, tcred->suid)) {
631 rdt_last_cmd_printf("No permission to move task %d\n", task->pid);
632 ret = -EPERM;
633 }
634
635 put_cred(tcred);
636 return ret;
637}
638
639static int rdtgroup_move_task(pid_t pid, struct rdtgroup *rdtgrp,
640 struct kernfs_open_file *of)
641{
642 struct task_struct *tsk;
643 int ret;
644
645 rcu_read_lock();
646 if (pid) {
647 tsk = find_task_by_vpid(pid);
648 if (!tsk) {
649 rcu_read_unlock();
650 rdt_last_cmd_printf("No task %d\n", pid);
651 return -ESRCH;
652 }
653 } else {
654 tsk = current;
655 }
656
657 get_task_struct(tsk);
658 rcu_read_unlock();
659
660 ret = rdtgroup_task_write_permission(tsk, of);
661 if (!ret)
662 ret = __rdtgroup_move_task(tsk, rdtgrp);
663
664 put_task_struct(tsk);
665 return ret;
666}
667
668static ssize_t rdtgroup_tasks_write(struct kernfs_open_file *of,
669 char *buf, size_t nbytes, loff_t off)
670{
671 struct rdtgroup *rdtgrp;
672 int ret = 0;
673 pid_t pid;
674
675 if (kstrtoint(strstrip(buf), 0, &pid) || pid < 0)
676 return -EINVAL;
677 rdtgrp = rdtgroup_kn_lock_live(of->kn);
678 if (!rdtgrp) {
679 rdtgroup_kn_unlock(of->kn);
680 return -ENOENT;
681 }
682 rdt_last_cmd_clear();
683
684 if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED ||
685 rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
686 ret = -EINVAL;
687 rdt_last_cmd_puts("Pseudo-locking in progress\n");
688 goto unlock;
689 }
690
691 ret = rdtgroup_move_task(pid, rdtgrp, of);
692
693unlock:
694 rdtgroup_kn_unlock(of->kn);
695
696 return ret ?: nbytes;
697}
698
699static void show_rdt_tasks(struct rdtgroup *r, struct seq_file *s)
700{
701 struct task_struct *p, *t;
702
703 rcu_read_lock();
704 for_each_process_thread(p, t) {
705 if ((r->type == RDTCTRL_GROUP && t->closid == r->closid) ||
706 (r->type == RDTMON_GROUP && t->rmid == r->mon.rmid))
707 seq_printf(s, "%d\n", t->pid);
708 }
709 rcu_read_unlock();
710}
711
712static int rdtgroup_tasks_show(struct kernfs_open_file *of,
713 struct seq_file *s, void *v)
714{
715 struct rdtgroup *rdtgrp;
716 int ret = 0;
717
718 rdtgrp = rdtgroup_kn_lock_live(of->kn);
719 if (rdtgrp)
720 show_rdt_tasks(rdtgrp, s);
721 else
722 ret = -ENOENT;
723 rdtgroup_kn_unlock(of->kn);
724
725 return ret;
726}
727
728static int rdt_last_cmd_status_show(struct kernfs_open_file *of,
729 struct seq_file *seq, void *v)
730{
731 int len;
732
733 mutex_lock(&rdtgroup_mutex);
734 len = seq_buf_used(&last_cmd_status);
735 if (len)
736 seq_printf(seq, "%.*s", len, last_cmd_status_buf);
737 else
738 seq_puts(seq, "ok\n");
739 mutex_unlock(&rdtgroup_mutex);
740 return 0;
741}
742
743static int rdt_num_closids_show(struct kernfs_open_file *of,
744 struct seq_file *seq, void *v)
745{
746 struct rdt_resource *r = of->kn->parent->priv;
747
748 seq_printf(seq, "%d\n", r->num_closid);
749 return 0;
750}
751
752static int rdt_default_ctrl_show(struct kernfs_open_file *of,
753 struct seq_file *seq, void *v)
754{
755 struct rdt_resource *r = of->kn->parent->priv;
756
757 seq_printf(seq, "%x\n", r->default_ctrl);
758 return 0;
759}
760
761static int rdt_min_cbm_bits_show(struct kernfs_open_file *of,
762 struct seq_file *seq, void *v)
763{
764 struct rdt_resource *r = of->kn->parent->priv;
765
766 seq_printf(seq, "%u\n", r->cache.min_cbm_bits);
767 return 0;
768}
769
770static int rdt_shareable_bits_show(struct kernfs_open_file *of,
771 struct seq_file *seq, void *v)
772{
773 struct rdt_resource *r = of->kn->parent->priv;
774
775 seq_printf(seq, "%x\n", r->cache.shareable_bits);
776 return 0;
777}
778
779/**
780 * rdt_bit_usage_show - Display current usage of resources
781 *
782 * A domain is a shared resource that can now be allocated differently. Here
783 * we display the current regions of the domain as an annotated bitmask.
784 * For each domain of this resource its allocation bitmask
785 * is annotated as below to indicate the current usage of the corresponding bit:
786 * 0 - currently unused
787 * X - currently available for sharing and used by software and hardware
788 * H - currently used by hardware only but available for software use
789 * S - currently used and shareable by software only
790 * E - currently used exclusively by one resource group
791 * P - currently pseudo-locked by one resource group
792 */
793static int rdt_bit_usage_show(struct kernfs_open_file *of,
794 struct seq_file *seq, void *v)
795{
796 struct rdt_resource *r = of->kn->parent->priv;
797 /*
798 * Use unsigned long even though only 32 bits are used to ensure
799 * test_bit() is used safely.
800 */
801 unsigned long sw_shareable = 0, hw_shareable = 0;
802 unsigned long exclusive = 0, pseudo_locked = 0;
803 struct rdt_domain *dom;
804 int i, hwb, swb, excl, psl;
805 enum rdtgrp_mode mode;
806 bool sep = false;
807 u32 *ctrl;
808
809 mutex_lock(&rdtgroup_mutex);
810 hw_shareable = r->cache.shareable_bits;
811 list_for_each_entry(dom, &r->domains, list) {
812 if (sep)
813 seq_putc(seq, ';');
814 ctrl = dom->ctrl_val;
815 sw_shareable = 0;
816 exclusive = 0;
817 seq_printf(seq, "%d=", dom->id);
818 for (i = 0; i < closids_supported(); i++, ctrl++) {
819 if (!closid_allocated(i))
820 continue;
821 mode = rdtgroup_mode_by_closid(i);
822 switch (mode) {
823 case RDT_MODE_SHAREABLE:
824 sw_shareable |= *ctrl;
825 break;
826 case RDT_MODE_EXCLUSIVE:
827 exclusive |= *ctrl;
828 break;
829 case RDT_MODE_PSEUDO_LOCKSETUP:
830 /*
831 * RDT_MODE_PSEUDO_LOCKSETUP is possible
832 * here but not included since the CBM
833 * associated with this CLOSID in this mode
834 * is not initialized and no task or cpu can be
835 * assigned this CLOSID.
836 */
837 break;
838 case RDT_MODE_PSEUDO_LOCKED:
839 case RDT_NUM_MODES:
840 WARN(1,
841 "invalid mode for closid %d\n", i);
842 break;
843 }
844 }
845 for (i = r->cache.cbm_len - 1; i >= 0; i--) {
846 pseudo_locked = dom->plr ? dom->plr->cbm : 0;
847 hwb = test_bit(i, &hw_shareable);
848 swb = test_bit(i, &sw_shareable);
849 excl = test_bit(i, &exclusive);
850 psl = test_bit(i, &pseudo_locked);
851 if (hwb && swb)
852 seq_putc(seq, 'X');
853 else if (hwb && !swb)
854 seq_putc(seq, 'H');
855 else if (!hwb && swb)
856 seq_putc(seq, 'S');
857 else if (excl)
858 seq_putc(seq, 'E');
859 else if (psl)
860 seq_putc(seq, 'P');
861 else /* Unused bits remain */
862 seq_putc(seq, '0');
863 }
864 sep = true;
865 }
866 seq_putc(seq, '\n');
867 mutex_unlock(&rdtgroup_mutex);
868 return 0;
869}
870
871static int rdt_min_bw_show(struct kernfs_open_file *of,
872 struct seq_file *seq, void *v)
873{
874 struct rdt_resource *r = of->kn->parent->priv;
875
876 seq_printf(seq, "%u\n", r->membw.min_bw);
877 return 0;
878}
879
880static int rdt_num_rmids_show(struct kernfs_open_file *of,
881 struct seq_file *seq, void *v)
882{
883 struct rdt_resource *r = of->kn->parent->priv;
884
885 seq_printf(seq, "%d\n", r->num_rmid);
886
887 return 0;
888}
889
890static int rdt_mon_features_show(struct kernfs_open_file *of,
891 struct seq_file *seq, void *v)
892{
893 struct rdt_resource *r = of->kn->parent->priv;
894 struct mon_evt *mevt;
895
896 list_for_each_entry(mevt, &r->evt_list, list)
897 seq_printf(seq, "%s\n", mevt->name);
898
899 return 0;
900}
901
902static int rdt_bw_gran_show(struct kernfs_open_file *of,
903 struct seq_file *seq, void *v)
904{
905 struct rdt_resource *r = of->kn->parent->priv;
906
907 seq_printf(seq, "%u\n", r->membw.bw_gran);
908 return 0;
909}
910
911static int rdt_delay_linear_show(struct kernfs_open_file *of,
912 struct seq_file *seq, void *v)
913{
914 struct rdt_resource *r = of->kn->parent->priv;
915
916 seq_printf(seq, "%u\n", r->membw.delay_linear);
917 return 0;
918}
919
920static int max_threshold_occ_show(struct kernfs_open_file *of,
921 struct seq_file *seq, void *v)
922{
923 struct rdt_resource *r = of->kn->parent->priv;
924
925 seq_printf(seq, "%u\n", resctrl_cqm_threshold * r->mon_scale);
926
927 return 0;
928}
929
930static ssize_t max_threshold_occ_write(struct kernfs_open_file *of,
931 char *buf, size_t nbytes, loff_t off)
932{
933 struct rdt_resource *r = of->kn->parent->priv;
934 unsigned int bytes;
935 int ret;
936
937 ret = kstrtouint(buf, 0, &bytes);
938 if (ret)
939 return ret;
940
941 if (bytes > (boot_cpu_data.x86_cache_size * 1024))
942 return -EINVAL;
943
944 resctrl_cqm_threshold = bytes / r->mon_scale;
945
946 return nbytes;
947}
948
949/*
950 * rdtgroup_mode_show - Display mode of this resource group
951 */
952static int rdtgroup_mode_show(struct kernfs_open_file *of,
953 struct seq_file *s, void *v)
954{
955 struct rdtgroup *rdtgrp;
956
957 rdtgrp = rdtgroup_kn_lock_live(of->kn);
958 if (!rdtgrp) {
959 rdtgroup_kn_unlock(of->kn);
960 return -ENOENT;
961 }
962
963 seq_printf(s, "%s\n", rdtgroup_mode_str(rdtgrp->mode));
964
965 rdtgroup_kn_unlock(of->kn);
966 return 0;
967}
968
969/**
970 * rdt_cdp_peer_get - Retrieve CDP peer if it exists
971 * @r: RDT resource to which RDT domain @d belongs
972 * @d: Cache instance for which a CDP peer is requested
973 * @r_cdp: RDT resource that shares hardware with @r (RDT resource peer)
974 * Used to return the result.
975 * @d_cdp: RDT domain that shares hardware with @d (RDT domain peer)
976 * Used to return the result.
977 *
978 * RDT resources are managed independently and by extension the RDT domains
979 * (RDT resource instances) are managed independently also. The Code and
980 * Data Prioritization (CDP) RDT resources, while managed independently,
981 * could refer to the same underlying hardware. For example,
982 * RDT_RESOURCE_L2CODE and RDT_RESOURCE_L2DATA both refer to the L2 cache.
983 *
984 * When provided with an RDT resource @r and an instance of that RDT
985 * resource @d rdt_cdp_peer_get() will return if there is a peer RDT
986 * resource and the exact instance that shares the same hardware.
987 *
988 * Return: 0 if a CDP peer was found, <0 on error or if no CDP peer exists.
989 * If a CDP peer was found, @r_cdp will point to the peer RDT resource
990 * and @d_cdp will point to the peer RDT domain.
991 */
992static int rdt_cdp_peer_get(struct rdt_resource *r, struct rdt_domain *d,
993 struct rdt_resource **r_cdp,
994 struct rdt_domain **d_cdp)
995{
996 struct rdt_resource *_r_cdp = NULL;
997 struct rdt_domain *_d_cdp = NULL;
998 int ret = 0;
999
1000 switch (r->rid) {
1001 case RDT_RESOURCE_L3DATA:
1002 _r_cdp = &rdt_resources_all[RDT_RESOURCE_L3CODE];
1003 break;
1004 case RDT_RESOURCE_L3CODE:
1005 _r_cdp = &rdt_resources_all[RDT_RESOURCE_L3DATA];
1006 break;
1007 case RDT_RESOURCE_L2DATA:
1008 _r_cdp = &rdt_resources_all[RDT_RESOURCE_L2CODE];
1009 break;
1010 case RDT_RESOURCE_L2CODE:
1011 _r_cdp = &rdt_resources_all[RDT_RESOURCE_L2DATA];
1012 break;
1013 default:
1014 ret = -ENOENT;
1015 goto out;
1016 }
1017
1018 /*
1019 * When a new CPU comes online and CDP is enabled then the new
1020 * RDT domains (if any) associated with both CDP RDT resources
1021 * are added in the same CPU online routine while the
1022 * rdtgroup_mutex is held. It should thus not happen for one
1023 * RDT domain to exist and be associated with its RDT CDP
1024 * resource but there is no RDT domain associated with the
1025 * peer RDT CDP resource. Hence the WARN.
1026 */
1027 _d_cdp = rdt_find_domain(_r_cdp, d->id, NULL);
1028 if (WARN_ON(IS_ERR_OR_NULL(_d_cdp))) {
1029 _r_cdp = NULL;
1030 ret = -EINVAL;
1031 }
1032
1033out:
1034 *r_cdp = _r_cdp;
1035 *d_cdp = _d_cdp;
1036
1037 return ret;
1038}
1039
1040/**
1041 * __rdtgroup_cbm_overlaps - Does CBM for intended closid overlap with other
1042 * @r: Resource to which domain instance @d belongs.
1043 * @d: The domain instance for which @closid is being tested.
1044 * @cbm: Capacity bitmask being tested.
1045 * @closid: Intended closid for @cbm.
1046 * @exclusive: Only check if overlaps with exclusive resource groups
1047 *
1048 * Checks if provided @cbm intended to be used for @closid on domain
1049 * @d overlaps with any other closids or other hardware usage associated
1050 * with this domain. If @exclusive is true then only overlaps with
1051 * resource groups in exclusive mode will be considered. If @exclusive
1052 * is false then overlaps with any resource group or hardware entities
1053 * will be considered.
1054 *
1055 * @cbm is unsigned long, even if only 32 bits are used, to make the
1056 * bitmap functions work correctly.
1057 *
1058 * Return: false if CBM does not overlap, true if it does.
1059 */
1060static bool __rdtgroup_cbm_overlaps(struct rdt_resource *r, struct rdt_domain *d,
1061 unsigned long cbm, int closid, bool exclusive)
1062{
1063 enum rdtgrp_mode mode;
1064 unsigned long ctrl_b;
1065 u32 *ctrl;
1066 int i;
1067
1068 /* Check for any overlap with regions used by hardware directly */
1069 if (!exclusive) {
1070 ctrl_b = r->cache.shareable_bits;
1071 if (bitmap_intersects(&cbm, &ctrl_b, r->cache.cbm_len))
1072 return true;
1073 }
1074
1075 /* Check for overlap with other resource groups */
1076 ctrl = d->ctrl_val;
1077 for (i = 0; i < closids_supported(); i++, ctrl++) {
1078 ctrl_b = *ctrl;
1079 mode = rdtgroup_mode_by_closid(i);
1080 if (closid_allocated(i) && i != closid &&
1081 mode != RDT_MODE_PSEUDO_LOCKSETUP) {
1082 if (bitmap_intersects(&cbm, &ctrl_b, r->cache.cbm_len)) {
1083 if (exclusive) {
1084 if (mode == RDT_MODE_EXCLUSIVE)
1085 return true;
1086 continue;
1087 }
1088 return true;
1089 }
1090 }
1091 }
1092
1093 return false;
1094}
1095
1096/**
1097 * rdtgroup_cbm_overlaps - Does CBM overlap with other use of hardware
1098 * @r: Resource to which domain instance @d belongs.
1099 * @d: The domain instance for which @closid is being tested.
1100 * @cbm: Capacity bitmask being tested.
1101 * @closid: Intended closid for @cbm.
1102 * @exclusive: Only check if overlaps with exclusive resource groups
1103 *
1104 * Resources that can be allocated using a CBM can use the CBM to control
1105 * the overlap of these allocations. rdtgroup_cmb_overlaps() is the test
1106 * for overlap. Overlap test is not limited to the specific resource for
1107 * which the CBM is intended though - when dealing with CDP resources that
1108 * share the underlying hardware the overlap check should be performed on
1109 * the CDP resource sharing the hardware also.
1110 *
1111 * Refer to description of __rdtgroup_cbm_overlaps() for the details of the
1112 * overlap test.
1113 *
1114 * Return: true if CBM overlap detected, false if there is no overlap
1115 */
1116bool rdtgroup_cbm_overlaps(struct rdt_resource *r, struct rdt_domain *d,
1117 unsigned long cbm, int closid, bool exclusive)
1118{
1119 struct rdt_resource *r_cdp;
1120 struct rdt_domain *d_cdp;
1121
1122 if (__rdtgroup_cbm_overlaps(r, d, cbm, closid, exclusive))
1123 return true;
1124
1125 if (rdt_cdp_peer_get(r, d, &r_cdp, &d_cdp) < 0)
1126 return false;
1127
1128 return __rdtgroup_cbm_overlaps(r_cdp, d_cdp, cbm, closid, exclusive);
1129}
1130
1131/**
1132 * rdtgroup_mode_test_exclusive - Test if this resource group can be exclusive
1133 *
1134 * An exclusive resource group implies that there should be no sharing of
1135 * its allocated resources. At the time this group is considered to be
1136 * exclusive this test can determine if its current schemata supports this
1137 * setting by testing for overlap with all other resource groups.
1138 *
1139 * Return: true if resource group can be exclusive, false if there is overlap
1140 * with allocations of other resource groups and thus this resource group
1141 * cannot be exclusive.
1142 */
1143static bool rdtgroup_mode_test_exclusive(struct rdtgroup *rdtgrp)
1144{
1145 int closid = rdtgrp->closid;
1146 struct rdt_resource *r;
1147 bool has_cache = false;
1148 struct rdt_domain *d;
1149
1150 for_each_alloc_enabled_rdt_resource(r) {
1151 if (r->rid == RDT_RESOURCE_MBA)
1152 continue;
1153 has_cache = true;
1154 list_for_each_entry(d, &r->domains, list) {
1155 if (rdtgroup_cbm_overlaps(r, d, d->ctrl_val[closid],
1156 rdtgrp->closid, false)) {
1157 rdt_last_cmd_puts("Schemata overlaps\n");
1158 return false;
1159 }
1160 }
1161 }
1162
1163 if (!has_cache) {
1164 rdt_last_cmd_puts("Cannot be exclusive without CAT/CDP\n");
1165 return false;
1166 }
1167
1168 return true;
1169}
1170
1171/**
1172 * rdtgroup_mode_write - Modify the resource group's mode
1173 *
1174 */
1175static ssize_t rdtgroup_mode_write(struct kernfs_open_file *of,
1176 char *buf, size_t nbytes, loff_t off)
1177{
1178 struct rdtgroup *rdtgrp;
1179 enum rdtgrp_mode mode;
1180 int ret = 0;
1181
1182 /* Valid input requires a trailing newline */
1183 if (nbytes == 0 || buf[nbytes - 1] != '\n')
1184 return -EINVAL;
1185 buf[nbytes - 1] = '\0';
1186
1187 rdtgrp = rdtgroup_kn_lock_live(of->kn);
1188 if (!rdtgrp) {
1189 rdtgroup_kn_unlock(of->kn);
1190 return -ENOENT;
1191 }
1192
1193 rdt_last_cmd_clear();
1194
1195 mode = rdtgrp->mode;
1196
1197 if ((!strcmp(buf, "shareable") && mode == RDT_MODE_SHAREABLE) ||
1198 (!strcmp(buf, "exclusive") && mode == RDT_MODE_EXCLUSIVE) ||
1199 (!strcmp(buf, "pseudo-locksetup") &&
1200 mode == RDT_MODE_PSEUDO_LOCKSETUP) ||
1201 (!strcmp(buf, "pseudo-locked") && mode == RDT_MODE_PSEUDO_LOCKED))
1202 goto out;
1203
1204 if (mode == RDT_MODE_PSEUDO_LOCKED) {
1205 rdt_last_cmd_puts("Cannot change pseudo-locked group\n");
1206 ret = -EINVAL;
1207 goto out;
1208 }
1209
1210 if (!strcmp(buf, "shareable")) {
1211 if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
1212 ret = rdtgroup_locksetup_exit(rdtgrp);
1213 if (ret)
1214 goto out;
1215 }
1216 rdtgrp->mode = RDT_MODE_SHAREABLE;
1217 } else if (!strcmp(buf, "exclusive")) {
1218 if (!rdtgroup_mode_test_exclusive(rdtgrp)) {
1219 ret = -EINVAL;
1220 goto out;
1221 }
1222 if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
1223 ret = rdtgroup_locksetup_exit(rdtgrp);
1224 if (ret)
1225 goto out;
1226 }
1227 rdtgrp->mode = RDT_MODE_EXCLUSIVE;
1228 } else if (!strcmp(buf, "pseudo-locksetup")) {
1229 ret = rdtgroup_locksetup_enter(rdtgrp);
1230 if (ret)
1231 goto out;
1232 rdtgrp->mode = RDT_MODE_PSEUDO_LOCKSETUP;
1233 } else {
1234 rdt_last_cmd_puts("Unknown or unsupported mode\n");
1235 ret = -EINVAL;
1236 }
1237
1238out:
1239 rdtgroup_kn_unlock(of->kn);
1240 return ret ?: nbytes;
1241}
1242
1243/**
1244 * rdtgroup_cbm_to_size - Translate CBM to size in bytes
1245 * @r: RDT resource to which @d belongs.
1246 * @d: RDT domain instance.
1247 * @cbm: bitmask for which the size should be computed.
1248 *
1249 * The bitmask provided associated with the RDT domain instance @d will be
1250 * translated into how many bytes it represents. The size in bytes is
1251 * computed by first dividing the total cache size by the CBM length to
1252 * determine how many bytes each bit in the bitmask represents. The result
1253 * is multiplied with the number of bits set in the bitmask.
1254 *
1255 * @cbm is unsigned long, even if only 32 bits are used to make the
1256 * bitmap functions work correctly.
1257 */
1258unsigned int rdtgroup_cbm_to_size(struct rdt_resource *r,
1259 struct rdt_domain *d, unsigned long cbm)
1260{
1261 struct cpu_cacheinfo *ci;
1262 unsigned int size = 0;
1263 int num_b, i;
1264
1265 num_b = bitmap_weight(&cbm, r->cache.cbm_len);
1266 ci = get_cpu_cacheinfo(cpumask_any(&d->cpu_mask));
1267 for (i = 0; i < ci->num_leaves; i++) {
1268 if (ci->info_list[i].level == r->cache_level) {
1269 size = ci->info_list[i].size / r->cache.cbm_len * num_b;
1270 break;
1271 }
1272 }
1273
1274 return size;
1275}
1276
1277/**
1278 * rdtgroup_size_show - Display size in bytes of allocated regions
1279 *
1280 * The "size" file mirrors the layout of the "schemata" file, printing the
1281 * size in bytes of each region instead of the capacity bitmask.
1282 *
1283 */
1284static int rdtgroup_size_show(struct kernfs_open_file *of,
1285 struct seq_file *s, void *v)
1286{
1287 struct rdtgroup *rdtgrp;
1288 struct rdt_resource *r;
1289 struct rdt_domain *d;
1290 unsigned int size;
1291 int ret = 0;
1292 bool sep;
1293 u32 ctrl;
1294
1295 rdtgrp = rdtgroup_kn_lock_live(of->kn);
1296 if (!rdtgrp) {
1297 rdtgroup_kn_unlock(of->kn);
1298 return -ENOENT;
1299 }
1300
1301 if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
1302 if (!rdtgrp->plr->d) {
1303 rdt_last_cmd_clear();
1304 rdt_last_cmd_puts("Cache domain offline\n");
1305 ret = -ENODEV;
1306 } else {
1307 seq_printf(s, "%*s:", max_name_width,
1308 rdtgrp->plr->r->name);
1309 size = rdtgroup_cbm_to_size(rdtgrp->plr->r,
1310 rdtgrp->plr->d,
1311 rdtgrp->plr->cbm);
1312 seq_printf(s, "%d=%u\n", rdtgrp->plr->d->id, size);
1313 }
1314 goto out;
1315 }
1316
1317 for_each_alloc_enabled_rdt_resource(r) {
1318 sep = false;
1319 seq_printf(s, "%*s:", max_name_width, r->name);
1320 list_for_each_entry(d, &r->domains, list) {
1321 if (sep)
1322 seq_putc(s, ';');
1323 if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
1324 size = 0;
1325 } else {
1326 ctrl = (!is_mba_sc(r) ?
1327 d->ctrl_val[rdtgrp->closid] :
1328 d->mbps_val[rdtgrp->closid]);
1329 if (r->rid == RDT_RESOURCE_MBA)
1330 size = ctrl;
1331 else
1332 size = rdtgroup_cbm_to_size(r, d, ctrl);
1333 }
1334 seq_printf(s, "%d=%u", d->id, size);
1335 sep = true;
1336 }
1337 seq_putc(s, '\n');
1338 }
1339
1340out:
1341 rdtgroup_kn_unlock(of->kn);
1342
1343 return ret;
1344}
1345
1346/* rdtgroup information files for one cache resource. */
1347static struct rftype res_common_files[] = {
1348 {
1349 .name = "last_cmd_status",
1350 .mode = 0444,
1351 .kf_ops = &rdtgroup_kf_single_ops,
1352 .seq_show = rdt_last_cmd_status_show,
1353 .fflags = RF_TOP_INFO,
1354 },
1355 {
1356 .name = "num_closids",
1357 .mode = 0444,
1358 .kf_ops = &rdtgroup_kf_single_ops,
1359 .seq_show = rdt_num_closids_show,
1360 .fflags = RF_CTRL_INFO,
1361 },
1362 {
1363 .name = "mon_features",
1364 .mode = 0444,
1365 .kf_ops = &rdtgroup_kf_single_ops,
1366 .seq_show = rdt_mon_features_show,
1367 .fflags = RF_MON_INFO,
1368 },
1369 {
1370 .name = "num_rmids",
1371 .mode = 0444,
1372 .kf_ops = &rdtgroup_kf_single_ops,
1373 .seq_show = rdt_num_rmids_show,
1374 .fflags = RF_MON_INFO,
1375 },
1376 {
1377 .name = "cbm_mask",
1378 .mode = 0444,
1379 .kf_ops = &rdtgroup_kf_single_ops,
1380 .seq_show = rdt_default_ctrl_show,
1381 .fflags = RF_CTRL_INFO | RFTYPE_RES_CACHE,
1382 },
1383 {
1384 .name = "min_cbm_bits",
1385 .mode = 0444,
1386 .kf_ops = &rdtgroup_kf_single_ops,
1387 .seq_show = rdt_min_cbm_bits_show,
1388 .fflags = RF_CTRL_INFO | RFTYPE_RES_CACHE,
1389 },
1390 {
1391 .name = "shareable_bits",
1392 .mode = 0444,
1393 .kf_ops = &rdtgroup_kf_single_ops,
1394 .seq_show = rdt_shareable_bits_show,
1395 .fflags = RF_CTRL_INFO | RFTYPE_RES_CACHE,
1396 },
1397 {
1398 .name = "bit_usage",
1399 .mode = 0444,
1400 .kf_ops = &rdtgroup_kf_single_ops,
1401 .seq_show = rdt_bit_usage_show,
1402 .fflags = RF_CTRL_INFO | RFTYPE_RES_CACHE,
1403 },
1404 {
1405 .name = "min_bandwidth",
1406 .mode = 0444,
1407 .kf_ops = &rdtgroup_kf_single_ops,
1408 .seq_show = rdt_min_bw_show,
1409 .fflags = RF_CTRL_INFO | RFTYPE_RES_MB,
1410 },
1411 {
1412 .name = "bandwidth_gran",
1413 .mode = 0444,
1414 .kf_ops = &rdtgroup_kf_single_ops,
1415 .seq_show = rdt_bw_gran_show,
1416 .fflags = RF_CTRL_INFO | RFTYPE_RES_MB,
1417 },
1418 {
1419 .name = "delay_linear",
1420 .mode = 0444,
1421 .kf_ops = &rdtgroup_kf_single_ops,
1422 .seq_show = rdt_delay_linear_show,
1423 .fflags = RF_CTRL_INFO | RFTYPE_RES_MB,
1424 },
1425 {
1426 .name = "max_threshold_occupancy",
1427 .mode = 0644,
1428 .kf_ops = &rdtgroup_kf_single_ops,
1429 .write = max_threshold_occ_write,
1430 .seq_show = max_threshold_occ_show,
1431 .fflags = RF_MON_INFO | RFTYPE_RES_CACHE,
1432 },
1433 {
1434 .name = "cpus",
1435 .mode = 0644,
1436 .kf_ops = &rdtgroup_kf_single_ops,
1437 .write = rdtgroup_cpus_write,
1438 .seq_show = rdtgroup_cpus_show,
1439 .fflags = RFTYPE_BASE,
1440 },
1441 {
1442 .name = "cpus_list",
1443 .mode = 0644,
1444 .kf_ops = &rdtgroup_kf_single_ops,
1445 .write = rdtgroup_cpus_write,
1446 .seq_show = rdtgroup_cpus_show,
1447 .flags = RFTYPE_FLAGS_CPUS_LIST,
1448 .fflags = RFTYPE_BASE,
1449 },
1450 {
1451 .name = "tasks",
1452 .mode = 0644,
1453 .kf_ops = &rdtgroup_kf_single_ops,
1454 .write = rdtgroup_tasks_write,
1455 .seq_show = rdtgroup_tasks_show,
1456 .fflags = RFTYPE_BASE,
1457 },
1458 {
1459 .name = "schemata",
1460 .mode = 0644,
1461 .kf_ops = &rdtgroup_kf_single_ops,
1462 .write = rdtgroup_schemata_write,
1463 .seq_show = rdtgroup_schemata_show,
1464 .fflags = RF_CTRL_BASE,
1465 },
1466 {
1467 .name = "mode",
1468 .mode = 0644,
1469 .kf_ops = &rdtgroup_kf_single_ops,
1470 .write = rdtgroup_mode_write,
1471 .seq_show = rdtgroup_mode_show,
1472 .fflags = RF_CTRL_BASE,
1473 },
1474 {
1475 .name = "size",
1476 .mode = 0444,
1477 .kf_ops = &rdtgroup_kf_single_ops,
1478 .seq_show = rdtgroup_size_show,
1479 .fflags = RF_CTRL_BASE,
1480 },
1481
1482};
1483
1484static int rdtgroup_add_files(struct kernfs_node *kn, unsigned long fflags)
1485{
1486 struct rftype *rfts, *rft;
1487 int ret, len;
1488
1489 rfts = res_common_files;
1490 len = ARRAY_SIZE(res_common_files);
1491
1492 lockdep_assert_held(&rdtgroup_mutex);
1493
1494 for (rft = rfts; rft < rfts + len; rft++) {
1495 if ((fflags & rft->fflags) == rft->fflags) {
1496 ret = rdtgroup_add_file(kn, rft);
1497 if (ret)
1498 goto error;
1499 }
1500 }
1501
1502 return 0;
1503error:
1504 pr_warn("Failed to add %s, err=%d\n", rft->name, ret);
1505 while (--rft >= rfts) {
1506 if ((fflags & rft->fflags) == rft->fflags)
1507 kernfs_remove_by_name(kn, rft->name);
1508 }
1509 return ret;
1510}
1511
1512/**
1513 * rdtgroup_kn_mode_restrict - Restrict user access to named resctrl file
1514 * @r: The resource group with which the file is associated.
1515 * @name: Name of the file
1516 *
1517 * The permissions of named resctrl file, directory, or link are modified
1518 * to not allow read, write, or execute by any user.
1519 *
1520 * WARNING: This function is intended to communicate to the user that the
1521 * resctrl file has been locked down - that it is not relevant to the
1522 * particular state the system finds itself in. It should not be relied
1523 * on to protect from user access because after the file's permissions
1524 * are restricted the user can still change the permissions using chmod
1525 * from the command line.
1526 *
1527 * Return: 0 on success, <0 on failure.
1528 */
1529int rdtgroup_kn_mode_restrict(struct rdtgroup *r, const char *name)
1530{
1531 struct iattr iattr = {.ia_valid = ATTR_MODE,};
1532 struct kernfs_node *kn;
1533 int ret = 0;
1534
1535 kn = kernfs_find_and_get_ns(r->kn, name, NULL);
1536 if (!kn)
1537 return -ENOENT;
1538
1539 switch (kernfs_type(kn)) {
1540 case KERNFS_DIR:
1541 iattr.ia_mode = S_IFDIR;
1542 break;
1543 case KERNFS_FILE:
1544 iattr.ia_mode = S_IFREG;
1545 break;
1546 case KERNFS_LINK:
1547 iattr.ia_mode = S_IFLNK;
1548 break;
1549 }
1550
1551 ret = kernfs_setattr(kn, &iattr);
1552 kernfs_put(kn);
1553 return ret;
1554}
1555
1556/**
1557 * rdtgroup_kn_mode_restore - Restore user access to named resctrl file
1558 * @r: The resource group with which the file is associated.
1559 * @name: Name of the file
1560 * @mask: Mask of permissions that should be restored
1561 *
1562 * Restore the permissions of the named file. If @name is a directory the
1563 * permissions of its parent will be used.
1564 *
1565 * Return: 0 on success, <0 on failure.
1566 */
1567int rdtgroup_kn_mode_restore(struct rdtgroup *r, const char *name,
1568 umode_t mask)
1569{
1570 struct iattr iattr = {.ia_valid = ATTR_MODE,};
1571 struct kernfs_node *kn, *parent;
1572 struct rftype *rfts, *rft;
1573 int ret, len;
1574
1575 rfts = res_common_files;
1576 len = ARRAY_SIZE(res_common_files);
1577
1578 for (rft = rfts; rft < rfts + len; rft++) {
1579 if (!strcmp(rft->name, name))
1580 iattr.ia_mode = rft->mode & mask;
1581 }
1582
1583 kn = kernfs_find_and_get_ns(r->kn, name, NULL);
1584 if (!kn)
1585 return -ENOENT;
1586
1587 switch (kernfs_type(kn)) {
1588 case KERNFS_DIR:
1589 parent = kernfs_get_parent(kn);
1590 if (parent) {
1591 iattr.ia_mode |= parent->mode;
1592 kernfs_put(parent);
1593 }
1594 iattr.ia_mode |= S_IFDIR;
1595 break;
1596 case KERNFS_FILE:
1597 iattr.ia_mode |= S_IFREG;
1598 break;
1599 case KERNFS_LINK:
1600 iattr.ia_mode |= S_IFLNK;
1601 break;
1602 }
1603
1604 ret = kernfs_setattr(kn, &iattr);
1605 kernfs_put(kn);
1606 return ret;
1607}
1608
1609static int rdtgroup_mkdir_info_resdir(struct rdt_resource *r, char *name,
1610 unsigned long fflags)
1611{
1612 struct kernfs_node *kn_subdir;
1613 int ret;
1614
1615 kn_subdir = kernfs_create_dir(kn_info, name,
1616 kn_info->mode, r);
1617 if (IS_ERR(kn_subdir))
1618 return PTR_ERR(kn_subdir);
1619
1620 kernfs_get(kn_subdir);
1621 ret = rdtgroup_kn_set_ugid(kn_subdir);
1622 if (ret)
1623 return ret;
1624
1625 ret = rdtgroup_add_files(kn_subdir, fflags);
1626 if (!ret)
1627 kernfs_activate(kn_subdir);
1628
1629 return ret;
1630}
1631
1632static int rdtgroup_create_info_dir(struct kernfs_node *parent_kn)
1633{
1634 struct rdt_resource *r;
1635 unsigned long fflags;
1636 char name[32];
1637 int ret;
1638
1639 /* create the directory */
1640 kn_info = kernfs_create_dir(parent_kn, "info", parent_kn->mode, NULL);
1641 if (IS_ERR(kn_info))
1642 return PTR_ERR(kn_info);
1643 kernfs_get(kn_info);
1644
1645 ret = rdtgroup_add_files(kn_info, RF_TOP_INFO);
1646 if (ret)
1647 goto out_destroy;
1648
1649 for_each_alloc_enabled_rdt_resource(r) {
1650 fflags = r->fflags | RF_CTRL_INFO;
1651 ret = rdtgroup_mkdir_info_resdir(r, r->name, fflags);
1652 if (ret)
1653 goto out_destroy;
1654 }
1655
1656 for_each_mon_enabled_rdt_resource(r) {
1657 fflags = r->fflags | RF_MON_INFO;
1658 sprintf(name, "%s_MON", r->name);
1659 ret = rdtgroup_mkdir_info_resdir(r, name, fflags);
1660 if (ret)
1661 goto out_destroy;
1662 }
1663
1664 /*
1665 * This extra ref will be put in kernfs_remove() and guarantees
1666 * that @rdtgrp->kn is always accessible.
1667 */
1668 kernfs_get(kn_info);
1669
1670 ret = rdtgroup_kn_set_ugid(kn_info);
1671 if (ret)
1672 goto out_destroy;
1673
1674 kernfs_activate(kn_info);
1675
1676 return 0;
1677
1678out_destroy:
1679 kernfs_remove(kn_info);
1680 return ret;
1681}
1682
1683static int
1684mongroup_create_dir(struct kernfs_node *parent_kn, struct rdtgroup *prgrp,
1685 char *name, struct kernfs_node **dest_kn)
1686{
1687 struct kernfs_node *kn;
1688 int ret;
1689
1690 /* create the directory */
1691 kn = kernfs_create_dir(parent_kn, name, parent_kn->mode, prgrp);
1692 if (IS_ERR(kn))
1693 return PTR_ERR(kn);
1694
1695 if (dest_kn)
1696 *dest_kn = kn;
1697
1698 /*
1699 * This extra ref will be put in kernfs_remove() and guarantees
1700 * that @rdtgrp->kn is always accessible.
1701 */
1702 kernfs_get(kn);
1703
1704 ret = rdtgroup_kn_set_ugid(kn);
1705 if (ret)
1706 goto out_destroy;
1707
1708 kernfs_activate(kn);
1709
1710 return 0;
1711
1712out_destroy:
1713 kernfs_remove(kn);
1714 return ret;
1715}
1716
1717static void l3_qos_cfg_update(void *arg)
1718{
1719 bool *enable = arg;
1720
1721 wrmsrl(MSR_IA32_L3_QOS_CFG, *enable ? L3_QOS_CDP_ENABLE : 0ULL);
1722}
1723
1724static void l2_qos_cfg_update(void *arg)
1725{
1726 bool *enable = arg;
1727
1728 wrmsrl(MSR_IA32_L2_QOS_CFG, *enable ? L2_QOS_CDP_ENABLE : 0ULL);
1729}
1730
1731static inline bool is_mba_linear(void)
1732{
1733 return rdt_resources_all[RDT_RESOURCE_MBA].membw.delay_linear;
1734}
1735
1736static int set_cache_qos_cfg(int level, bool enable)
1737{
1738 void (*update)(void *arg);
1739 struct rdt_resource *r_l;
1740 cpumask_var_t cpu_mask;
1741 struct rdt_domain *d;
1742 int cpu;
1743
1744 if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL))
1745 return -ENOMEM;
1746
1747 if (level == RDT_RESOURCE_L3)
1748 update = l3_qos_cfg_update;
1749 else if (level == RDT_RESOURCE_L2)
1750 update = l2_qos_cfg_update;
1751 else
1752 return -EINVAL;
1753
1754 r_l = &rdt_resources_all[level];
1755 list_for_each_entry(d, &r_l->domains, list) {
1756 /* Pick one CPU from each domain instance to update MSR */
1757 cpumask_set_cpu(cpumask_any(&d->cpu_mask), cpu_mask);
1758 }
1759 cpu = get_cpu();
1760 /* Update QOS_CFG MSR on this cpu if it's in cpu_mask. */
1761 if (cpumask_test_cpu(cpu, cpu_mask))
1762 update(&enable);
1763 /* Update QOS_CFG MSR on all other cpus in cpu_mask. */
1764 smp_call_function_many(cpu_mask, update, &enable, 1);
1765 put_cpu();
1766
1767 free_cpumask_var(cpu_mask);
1768
1769 return 0;
1770}
1771
1772/*
1773 * Enable or disable the MBA software controller
1774 * which helps user specify bandwidth in MBps.
1775 * MBA software controller is supported only if
1776 * MBM is supported and MBA is in linear scale.
1777 */
1778static int set_mba_sc(bool mba_sc)
1779{
1780 struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_MBA];
1781 struct rdt_domain *d;
1782
1783 if (!is_mbm_enabled() || !is_mba_linear() ||
1784 mba_sc == is_mba_sc(r))
1785 return -EINVAL;
1786
1787 r->membw.mba_sc = mba_sc;
1788 list_for_each_entry(d, &r->domains, list)
1789 setup_default_ctrlval(r, d->ctrl_val, d->mbps_val);
1790
1791 return 0;
1792}
1793
1794static int cdp_enable(int level, int data_type, int code_type)
1795{
1796 struct rdt_resource *r_ldata = &rdt_resources_all[data_type];
1797 struct rdt_resource *r_lcode = &rdt_resources_all[code_type];
1798 struct rdt_resource *r_l = &rdt_resources_all[level];
1799 int ret;
1800
1801 if (!r_l->alloc_capable || !r_ldata->alloc_capable ||
1802 !r_lcode->alloc_capable)
1803 return -EINVAL;
1804
1805 ret = set_cache_qos_cfg(level, true);
1806 if (!ret) {
1807 r_l->alloc_enabled = false;
1808 r_ldata->alloc_enabled = true;
1809 r_lcode->alloc_enabled = true;
1810 }
1811 return ret;
1812}
1813
1814static int cdpl3_enable(void)
1815{
1816 return cdp_enable(RDT_RESOURCE_L3, RDT_RESOURCE_L3DATA,
1817 RDT_RESOURCE_L3CODE);
1818}
1819
1820static int cdpl2_enable(void)
1821{
1822 return cdp_enable(RDT_RESOURCE_L2, RDT_RESOURCE_L2DATA,
1823 RDT_RESOURCE_L2CODE);
1824}
1825
1826static void cdp_disable(int level, int data_type, int code_type)
1827{
1828 struct rdt_resource *r = &rdt_resources_all[level];
1829
1830 r->alloc_enabled = r->alloc_capable;
1831
1832 if (rdt_resources_all[data_type].alloc_enabled) {
1833 rdt_resources_all[data_type].alloc_enabled = false;
1834 rdt_resources_all[code_type].alloc_enabled = false;
1835 set_cache_qos_cfg(level, false);
1836 }
1837}
1838
1839static void cdpl3_disable(void)
1840{
1841 cdp_disable(RDT_RESOURCE_L3, RDT_RESOURCE_L3DATA, RDT_RESOURCE_L3CODE);
1842}
1843
1844static void cdpl2_disable(void)
1845{
1846 cdp_disable(RDT_RESOURCE_L2, RDT_RESOURCE_L2DATA, RDT_RESOURCE_L2CODE);
1847}
1848
1849static void cdp_disable_all(void)
1850{
1851 if (rdt_resources_all[RDT_RESOURCE_L3DATA].alloc_enabled)
1852 cdpl3_disable();
1853 if (rdt_resources_all[RDT_RESOURCE_L2DATA].alloc_enabled)
1854 cdpl2_disable();
1855}
1856
1857/*
1858 * We don't allow rdtgroup directories to be created anywhere
1859 * except the root directory. Thus when looking for the rdtgroup
1860 * structure for a kernfs node we are either looking at a directory,
1861 * in which case the rdtgroup structure is pointed at by the "priv"
1862 * field, otherwise we have a file, and need only look to the parent
1863 * to find the rdtgroup.
1864 */
1865static struct rdtgroup *kernfs_to_rdtgroup(struct kernfs_node *kn)
1866{
1867 if (kernfs_type(kn) == KERNFS_DIR) {
1868 /*
1869 * All the resource directories use "kn->priv"
1870 * to point to the "struct rdtgroup" for the
1871 * resource. "info" and its subdirectories don't
1872 * have rdtgroup structures, so return NULL here.
1873 */
1874 if (kn == kn_info || kn->parent == kn_info)
1875 return NULL;
1876 else
1877 return kn->priv;
1878 } else {
1879 return kn->parent->priv;
1880 }
1881}
1882
1883struct rdtgroup *rdtgroup_kn_lock_live(struct kernfs_node *kn)
1884{
1885 struct rdtgroup *rdtgrp = kernfs_to_rdtgroup(kn);
1886
1887 if (!rdtgrp)
1888 return NULL;
1889
1890 atomic_inc(&rdtgrp->waitcount);
1891 kernfs_break_active_protection(kn);
1892
1893 mutex_lock(&rdtgroup_mutex);
1894
1895 /* Was this group deleted while we waited? */
1896 if (rdtgrp->flags & RDT_DELETED)
1897 return NULL;
1898
1899 return rdtgrp;
1900}
1901
1902void rdtgroup_kn_unlock(struct kernfs_node *kn)
1903{
1904 struct rdtgroup *rdtgrp = kernfs_to_rdtgroup(kn);
1905
1906 if (!rdtgrp)
1907 return;
1908
1909 mutex_unlock(&rdtgroup_mutex);
1910
1911 if (atomic_dec_and_test(&rdtgrp->waitcount) &&
1912 (rdtgrp->flags & RDT_DELETED)) {
1913 if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP ||
1914 rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED)
1915 rdtgroup_pseudo_lock_remove(rdtgrp);
1916 kernfs_unbreak_active_protection(kn);
1917 kernfs_put(rdtgrp->kn);
1918 kfree(rdtgrp);
1919 } else {
1920 kernfs_unbreak_active_protection(kn);
1921 }
1922}
1923
1924static int mkdir_mondata_all(struct kernfs_node *parent_kn,
1925 struct rdtgroup *prgrp,
1926 struct kernfs_node **mon_data_kn);
1927
1928static int rdt_enable_ctx(struct rdt_fs_context *ctx)
1929{
1930 int ret = 0;
1931
1932 if (ctx->enable_cdpl2)
1933 ret = cdpl2_enable();
1934
1935 if (!ret && ctx->enable_cdpl3)
1936 ret = cdpl3_enable();
1937
1938 if (!ret && ctx->enable_mba_mbps)
1939 ret = set_mba_sc(true);
1940
1941 return ret;
1942}
1943
1944static int rdt_get_tree(struct fs_context *fc)
1945{
1946 struct rdt_fs_context *ctx = rdt_fc2context(fc);
1947 struct rdt_domain *dom;
1948 struct rdt_resource *r;
1949 int ret;
1950
1951 cpus_read_lock();
1952 mutex_lock(&rdtgroup_mutex);
1953 /*
1954 * resctrl file system can only be mounted once.
1955 */
1956 if (static_branch_unlikely(&rdt_enable_key)) {
1957 ret = -EBUSY;
1958 goto out;
1959 }
1960
1961 ret = rdt_enable_ctx(ctx);
1962 if (ret < 0)
1963 goto out_cdp;
1964
1965 closid_init();
1966
1967 ret = rdtgroup_create_info_dir(rdtgroup_default.kn);
1968 if (ret < 0)
1969 goto out_mba;
1970
1971 if (rdt_mon_capable) {
1972 ret = mongroup_create_dir(rdtgroup_default.kn,
1973 NULL, "mon_groups",
1974 &kn_mongrp);
1975 if (ret < 0)
1976 goto out_info;
1977 kernfs_get(kn_mongrp);
1978
1979 ret = mkdir_mondata_all(rdtgroup_default.kn,
1980 &rdtgroup_default, &kn_mondata);
1981 if (ret < 0)
1982 goto out_mongrp;
1983 kernfs_get(kn_mondata);
1984 rdtgroup_default.mon.mon_data_kn = kn_mondata;
1985 }
1986
1987 ret = rdt_pseudo_lock_init();
1988 if (ret)
1989 goto out_mondata;
1990
1991 ret = kernfs_get_tree(fc);
1992 if (ret < 0)
1993 goto out_psl;
1994
1995 if (rdt_alloc_capable)
1996 static_branch_enable_cpuslocked(&rdt_alloc_enable_key);
1997 if (rdt_mon_capable)
1998 static_branch_enable_cpuslocked(&rdt_mon_enable_key);
1999
2000 if (rdt_alloc_capable || rdt_mon_capable)
2001 static_branch_enable_cpuslocked(&rdt_enable_key);
2002
2003 if (is_mbm_enabled()) {
2004 r = &rdt_resources_all[RDT_RESOURCE_L3];
2005 list_for_each_entry(dom, &r->domains, list)
2006 mbm_setup_overflow_handler(dom, MBM_OVERFLOW_INTERVAL);
2007 }
2008
2009 goto out;
2010
2011out_psl:
2012 rdt_pseudo_lock_release();
2013out_mondata:
2014 if (rdt_mon_capable)
2015 kernfs_remove(kn_mondata);
2016out_mongrp:
2017 if (rdt_mon_capable)
2018 kernfs_remove(kn_mongrp);
2019out_info:
2020 kernfs_remove(kn_info);
2021out_mba:
2022 if (ctx->enable_mba_mbps)
2023 set_mba_sc(false);
2024out_cdp:
2025 cdp_disable_all();
2026out:
2027 rdt_last_cmd_clear();
2028 mutex_unlock(&rdtgroup_mutex);
2029 cpus_read_unlock();
2030 return ret;
2031}
2032
2033enum rdt_param {
2034 Opt_cdp,
2035 Opt_cdpl2,
2036 Opt_mba_mbps,
2037 nr__rdt_params
2038};
2039
2040static const struct fs_parameter_spec rdt_param_specs[] = {
2041 fsparam_flag("cdp", Opt_cdp),
2042 fsparam_flag("cdpl2", Opt_cdpl2),
2043 fsparam_flag("mba_MBps", Opt_mba_mbps),
2044 {}
2045};
2046
2047static const struct fs_parameter_description rdt_fs_parameters = {
2048 .name = "rdt",
2049 .specs = rdt_param_specs,
2050};
2051
2052static int rdt_parse_param(struct fs_context *fc, struct fs_parameter *param)
2053{
2054 struct rdt_fs_context *ctx = rdt_fc2context(fc);
2055 struct fs_parse_result result;
2056 int opt;
2057
2058 opt = fs_parse(fc, &rdt_fs_parameters, param, &result);
2059 if (opt < 0)
2060 return opt;
2061
2062 switch (opt) {
2063 case Opt_cdp:
2064 ctx->enable_cdpl3 = true;
2065 return 0;
2066 case Opt_cdpl2:
2067 ctx->enable_cdpl2 = true;
2068 return 0;
2069 case Opt_mba_mbps:
2070 if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
2071 return -EINVAL;
2072 ctx->enable_mba_mbps = true;
2073 return 0;
2074 }
2075
2076 return -EINVAL;
2077}
2078
2079static void rdt_fs_context_free(struct fs_context *fc)
2080{
2081 struct rdt_fs_context *ctx = rdt_fc2context(fc);
2082
2083 kernfs_free_fs_context(fc);
2084 kfree(ctx);
2085}
2086
2087static const struct fs_context_operations rdt_fs_context_ops = {
2088 .free = rdt_fs_context_free,
2089 .parse_param = rdt_parse_param,
2090 .get_tree = rdt_get_tree,
2091};
2092
2093static int rdt_init_fs_context(struct fs_context *fc)
2094{
2095 struct rdt_fs_context *ctx;
2096
2097 ctx = kzalloc(sizeof(struct rdt_fs_context), GFP_KERNEL);
2098 if (!ctx)
2099 return -ENOMEM;
2100
2101 ctx->kfc.root = rdt_root;
2102 ctx->kfc.magic = RDTGROUP_SUPER_MAGIC;
2103 fc->fs_private = &ctx->kfc;
2104 fc->ops = &rdt_fs_context_ops;
2105 put_user_ns(fc->user_ns);
2106 fc->user_ns = get_user_ns(&init_user_ns);
2107 fc->global = true;
2108 return 0;
2109}
2110
2111static int reset_all_ctrls(struct rdt_resource *r)
2112{
2113 struct msr_param msr_param;
2114 cpumask_var_t cpu_mask;
2115 struct rdt_domain *d;
2116 int i, cpu;
2117
2118 if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL))
2119 return -ENOMEM;
2120
2121 msr_param.res = r;
2122 msr_param.low = 0;
2123 msr_param.high = r->num_closid;
2124
2125 /*
2126 * Disable resource control for this resource by setting all
2127 * CBMs in all domains to the maximum mask value. Pick one CPU
2128 * from each domain to update the MSRs below.
2129 */
2130 list_for_each_entry(d, &r->domains, list) {
2131 cpumask_set_cpu(cpumask_any(&d->cpu_mask), cpu_mask);
2132
2133 for (i = 0; i < r->num_closid; i++)
2134 d->ctrl_val[i] = r->default_ctrl;
2135 }
2136 cpu = get_cpu();
2137 /* Update CBM on this cpu if it's in cpu_mask. */
2138 if (cpumask_test_cpu(cpu, cpu_mask))
2139 rdt_ctrl_update(&msr_param);
2140 /* Update CBM on all other cpus in cpu_mask. */
2141 smp_call_function_many(cpu_mask, rdt_ctrl_update, &msr_param, 1);
2142 put_cpu();
2143
2144 free_cpumask_var(cpu_mask);
2145
2146 return 0;
2147}
2148
2149static bool is_closid_match(struct task_struct *t, struct rdtgroup *r)
2150{
2151 return (rdt_alloc_capable &&
2152 (r->type == RDTCTRL_GROUP) && (t->closid == r->closid));
2153}
2154
2155static bool is_rmid_match(struct task_struct *t, struct rdtgroup *r)
2156{
2157 return (rdt_mon_capable &&
2158 (r->type == RDTMON_GROUP) && (t->rmid == r->mon.rmid));
2159}
2160
2161/*
2162 * Move tasks from one to the other group. If @from is NULL, then all tasks
2163 * in the systems are moved unconditionally (used for teardown).
2164 *
2165 * If @mask is not NULL the cpus on which moved tasks are running are set
2166 * in that mask so the update smp function call is restricted to affected
2167 * cpus.
2168 */
2169static void rdt_move_group_tasks(struct rdtgroup *from, struct rdtgroup *to,
2170 struct cpumask *mask)
2171{
2172 struct task_struct *p, *t;
2173
2174 read_lock(&tasklist_lock);
2175 for_each_process_thread(p, t) {
2176 if (!from || is_closid_match(t, from) ||
2177 is_rmid_match(t, from)) {
2178 t->closid = to->closid;
2179 t->rmid = to->mon.rmid;
2180
2181#ifdef CONFIG_SMP
2182 /*
2183 * This is safe on x86 w/o barriers as the ordering
2184 * of writing to task_cpu() and t->on_cpu is
2185 * reverse to the reading here. The detection is
2186 * inaccurate as tasks might move or schedule
2187 * before the smp function call takes place. In
2188 * such a case the function call is pointless, but
2189 * there is no other side effect.
2190 */
2191 if (mask && t->on_cpu)
2192 cpumask_set_cpu(task_cpu(t), mask);
2193#endif
2194 }
2195 }
2196 read_unlock(&tasklist_lock);
2197}
2198
2199static void free_all_child_rdtgrp(struct rdtgroup *rdtgrp)
2200{
2201 struct rdtgroup *sentry, *stmp;
2202 struct list_head *head;
2203
2204 head = &rdtgrp->mon.crdtgrp_list;
2205 list_for_each_entry_safe(sentry, stmp, head, mon.crdtgrp_list) {
2206 free_rmid(sentry->mon.rmid);
2207 list_del(&sentry->mon.crdtgrp_list);
2208 kfree(sentry);
2209 }
2210}
2211
2212/*
2213 * Forcibly remove all of subdirectories under root.
2214 */
2215static void rmdir_all_sub(void)
2216{
2217 struct rdtgroup *rdtgrp, *tmp;
2218
2219 /* Move all tasks to the default resource group */
2220 rdt_move_group_tasks(NULL, &rdtgroup_default, NULL);
2221
2222 list_for_each_entry_safe(rdtgrp, tmp, &rdt_all_groups, rdtgroup_list) {
2223 /* Free any child rmids */
2224 free_all_child_rdtgrp(rdtgrp);
2225
2226 /* Remove each rdtgroup other than root */
2227 if (rdtgrp == &rdtgroup_default)
2228 continue;
2229
2230 if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP ||
2231 rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED)
2232 rdtgroup_pseudo_lock_remove(rdtgrp);
2233
2234 /*
2235 * Give any CPUs back to the default group. We cannot copy
2236 * cpu_online_mask because a CPU might have executed the
2237 * offline callback already, but is still marked online.
2238 */
2239 cpumask_or(&rdtgroup_default.cpu_mask,
2240 &rdtgroup_default.cpu_mask, &rdtgrp->cpu_mask);
2241
2242 free_rmid(rdtgrp->mon.rmid);
2243
2244 kernfs_remove(rdtgrp->kn);
2245 list_del(&rdtgrp->rdtgroup_list);
2246 kfree(rdtgrp);
2247 }
2248 /* Notify online CPUs to update per cpu storage and PQR_ASSOC MSR */
2249 update_closid_rmid(cpu_online_mask, &rdtgroup_default);
2250
2251 kernfs_remove(kn_info);
2252 kernfs_remove(kn_mongrp);
2253 kernfs_remove(kn_mondata);
2254}
2255
2256static void rdt_kill_sb(struct super_block *sb)
2257{
2258 struct rdt_resource *r;
2259
2260 cpus_read_lock();
2261 mutex_lock(&rdtgroup_mutex);
2262
2263 set_mba_sc(false);
2264
2265 /*Put everything back to default values. */
2266 for_each_alloc_enabled_rdt_resource(r)
2267 reset_all_ctrls(r);
2268 cdp_disable_all();
2269 rmdir_all_sub();
2270 rdt_pseudo_lock_release();
2271 rdtgroup_default.mode = RDT_MODE_SHAREABLE;
2272 static_branch_disable_cpuslocked(&rdt_alloc_enable_key);
2273 static_branch_disable_cpuslocked(&rdt_mon_enable_key);
2274 static_branch_disable_cpuslocked(&rdt_enable_key);
2275 kernfs_kill_sb(sb);
2276 mutex_unlock(&rdtgroup_mutex);
2277 cpus_read_unlock();
2278}
2279
2280static struct file_system_type rdt_fs_type = {
2281 .name = "resctrl",
2282 .init_fs_context = rdt_init_fs_context,
2283 .parameters = &rdt_fs_parameters,
2284 .kill_sb = rdt_kill_sb,
2285};
2286
2287static int mon_addfile(struct kernfs_node *parent_kn, const char *name,
2288 void *priv)
2289{
2290 struct kernfs_node *kn;
2291 int ret = 0;
2292
2293 kn = __kernfs_create_file(parent_kn, name, 0444,
2294 GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, 0,
2295 &kf_mondata_ops, priv, NULL, NULL);
2296 if (IS_ERR(kn))
2297 return PTR_ERR(kn);
2298
2299 ret = rdtgroup_kn_set_ugid(kn);
2300 if (ret) {
2301 kernfs_remove(kn);
2302 return ret;
2303 }
2304
2305 return ret;
2306}
2307
2308/*
2309 * Remove all subdirectories of mon_data of ctrl_mon groups
2310 * and monitor groups with given domain id.
2311 */
2312void rmdir_mondata_subdir_allrdtgrp(struct rdt_resource *r, unsigned int dom_id)
2313{
2314 struct rdtgroup *prgrp, *crgrp;
2315 char name[32];
2316
2317 if (!r->mon_enabled)
2318 return;
2319
2320 list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) {
2321 sprintf(name, "mon_%s_%02d", r->name, dom_id);
2322 kernfs_remove_by_name(prgrp->mon.mon_data_kn, name);
2323
2324 list_for_each_entry(crgrp, &prgrp->mon.crdtgrp_list, mon.crdtgrp_list)
2325 kernfs_remove_by_name(crgrp->mon.mon_data_kn, name);
2326 }
2327}
2328
2329static int mkdir_mondata_subdir(struct kernfs_node *parent_kn,
2330 struct rdt_domain *d,
2331 struct rdt_resource *r, struct rdtgroup *prgrp)
2332{
2333 union mon_data_bits priv;
2334 struct kernfs_node *kn;
2335 struct mon_evt *mevt;
2336 struct rmid_read rr;
2337 char name[32];
2338 int ret;
2339
2340 sprintf(name, "mon_%s_%02d", r->name, d->id);
2341 /* create the directory */
2342 kn = kernfs_create_dir(parent_kn, name, parent_kn->mode, prgrp);
2343 if (IS_ERR(kn))
2344 return PTR_ERR(kn);
2345
2346 /*
2347 * This extra ref will be put in kernfs_remove() and guarantees
2348 * that kn is always accessible.
2349 */
2350 kernfs_get(kn);
2351 ret = rdtgroup_kn_set_ugid(kn);
2352 if (ret)
2353 goto out_destroy;
2354
2355 if (WARN_ON(list_empty(&r->evt_list))) {
2356 ret = -EPERM;
2357 goto out_destroy;
2358 }
2359
2360 priv.u.rid = r->rid;
2361 priv.u.domid = d->id;
2362 list_for_each_entry(mevt, &r->evt_list, list) {
2363 priv.u.evtid = mevt->evtid;
2364 ret = mon_addfile(kn, mevt->name, priv.priv);
2365 if (ret)
2366 goto out_destroy;
2367
2368 if (is_mbm_event(mevt->evtid))
2369 mon_event_read(&rr, d, prgrp, mevt->evtid, true);
2370 }
2371 kernfs_activate(kn);
2372 return 0;
2373
2374out_destroy:
2375 kernfs_remove(kn);
2376 return ret;
2377}
2378
2379/*
2380 * Add all subdirectories of mon_data for "ctrl_mon" groups
2381 * and "monitor" groups with given domain id.
2382 */
2383void mkdir_mondata_subdir_allrdtgrp(struct rdt_resource *r,
2384 struct rdt_domain *d)
2385{
2386 struct kernfs_node *parent_kn;
2387 struct rdtgroup *prgrp, *crgrp;
2388 struct list_head *head;
2389
2390 if (!r->mon_enabled)
2391 return;
2392
2393 list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) {
2394 parent_kn = prgrp->mon.mon_data_kn;
2395 mkdir_mondata_subdir(parent_kn, d, r, prgrp);
2396
2397 head = &prgrp->mon.crdtgrp_list;
2398 list_for_each_entry(crgrp, head, mon.crdtgrp_list) {
2399 parent_kn = crgrp->mon.mon_data_kn;
2400 mkdir_mondata_subdir(parent_kn, d, r, crgrp);
2401 }
2402 }
2403}
2404
2405static int mkdir_mondata_subdir_alldom(struct kernfs_node *parent_kn,
2406 struct rdt_resource *r,
2407 struct rdtgroup *prgrp)
2408{
2409 struct rdt_domain *dom;
2410 int ret;
2411
2412 list_for_each_entry(dom, &r->domains, list) {
2413 ret = mkdir_mondata_subdir(parent_kn, dom, r, prgrp);
2414 if (ret)
2415 return ret;
2416 }
2417
2418 return 0;
2419}
2420
2421/*
2422 * This creates a directory mon_data which contains the monitored data.
2423 *
2424 * mon_data has one directory for each domain whic are named
2425 * in the format mon_<domain_name>_<domain_id>. For ex: A mon_data
2426 * with L3 domain looks as below:
2427 * ./mon_data:
2428 * mon_L3_00
2429 * mon_L3_01
2430 * mon_L3_02
2431 * ...
2432 *
2433 * Each domain directory has one file per event:
2434 * ./mon_L3_00/:
2435 * llc_occupancy
2436 *
2437 */
2438static int mkdir_mondata_all(struct kernfs_node *parent_kn,
2439 struct rdtgroup *prgrp,
2440 struct kernfs_node **dest_kn)
2441{
2442 struct rdt_resource *r;
2443 struct kernfs_node *kn;
2444 int ret;
2445
2446 /*
2447 * Create the mon_data directory first.
2448 */
2449 ret = mongroup_create_dir(parent_kn, NULL, "mon_data", &kn);
2450 if (ret)
2451 return ret;
2452
2453 if (dest_kn)
2454 *dest_kn = kn;
2455
2456 /*
2457 * Create the subdirectories for each domain. Note that all events
2458 * in a domain like L3 are grouped into a resource whose domain is L3
2459 */
2460 for_each_mon_enabled_rdt_resource(r) {
2461 ret = mkdir_mondata_subdir_alldom(kn, r, prgrp);
2462 if (ret)
2463 goto out_destroy;
2464 }
2465
2466 return 0;
2467
2468out_destroy:
2469 kernfs_remove(kn);
2470 return ret;
2471}
2472
2473/**
2474 * cbm_ensure_valid - Enforce validity on provided CBM
2475 * @_val: Candidate CBM
2476 * @r: RDT resource to which the CBM belongs
2477 *
2478 * The provided CBM represents all cache portions available for use. This
2479 * may be represented by a bitmap that does not consist of contiguous ones
2480 * and thus be an invalid CBM.
2481 * Here the provided CBM is forced to be a valid CBM by only considering
2482 * the first set of contiguous bits as valid and clearing all bits.
2483 * The intention here is to provide a valid default CBM with which a new
2484 * resource group is initialized. The user can follow this with a
2485 * modification to the CBM if the default does not satisfy the
2486 * requirements.
2487 */
2488static u32 cbm_ensure_valid(u32 _val, struct rdt_resource *r)
2489{
2490 unsigned int cbm_len = r->cache.cbm_len;
2491 unsigned long first_bit, zero_bit;
2492 unsigned long val = _val;
2493
2494 if (!val)
2495 return 0;
2496
2497 first_bit = find_first_bit(&val, cbm_len);
2498 zero_bit = find_next_zero_bit(&val, cbm_len, first_bit);
2499
2500 /* Clear any remaining bits to ensure contiguous region */
2501 bitmap_clear(&val, zero_bit, cbm_len - zero_bit);
2502 return (u32)val;
2503}
2504
2505/*
2506 * Initialize cache resources per RDT domain
2507 *
2508 * Set the RDT domain up to start off with all usable allocations. That is,
2509 * all shareable and unused bits. All-zero CBM is invalid.
2510 */
2511static int __init_one_rdt_domain(struct rdt_domain *d, struct rdt_resource *r,
2512 u32 closid)
2513{
2514 struct rdt_resource *r_cdp = NULL;
2515 struct rdt_domain *d_cdp = NULL;
2516 u32 used_b = 0, unused_b = 0;
2517 unsigned long tmp_cbm;
2518 enum rdtgrp_mode mode;
2519 u32 peer_ctl, *ctrl;
2520 int i;
2521
2522 rdt_cdp_peer_get(r, d, &r_cdp, &d_cdp);
2523 d->have_new_ctrl = false;
2524 d->new_ctrl = r->cache.shareable_bits;
2525 used_b = r->cache.shareable_bits;
2526 ctrl = d->ctrl_val;
2527 for (i = 0; i < closids_supported(); i++, ctrl++) {
2528 if (closid_allocated(i) && i != closid) {
2529 mode = rdtgroup_mode_by_closid(i);
2530 if (mode == RDT_MODE_PSEUDO_LOCKSETUP)
2531 /*
2532 * ctrl values for locksetup aren't relevant
2533 * until the schemata is written, and the mode
2534 * becomes RDT_MODE_PSEUDO_LOCKED.
2535 */
2536 continue;
2537 /*
2538 * If CDP is active include peer domain's
2539 * usage to ensure there is no overlap
2540 * with an exclusive group.
2541 */
2542 if (d_cdp)
2543 peer_ctl = d_cdp->ctrl_val[i];
2544 else
2545 peer_ctl = 0;
2546 used_b |= *ctrl | peer_ctl;
2547 if (mode == RDT_MODE_SHAREABLE)
2548 d->new_ctrl |= *ctrl | peer_ctl;
2549 }
2550 }
2551 if (d->plr && d->plr->cbm > 0)
2552 used_b |= d->plr->cbm;
2553 unused_b = used_b ^ (BIT_MASK(r->cache.cbm_len) - 1);
2554 unused_b &= BIT_MASK(r->cache.cbm_len) - 1;
2555 d->new_ctrl |= unused_b;
2556 /*
2557 * Force the initial CBM to be valid, user can
2558 * modify the CBM based on system availability.
2559 */
2560 d->new_ctrl = cbm_ensure_valid(d->new_ctrl, r);
2561 /*
2562 * Assign the u32 CBM to an unsigned long to ensure that
2563 * bitmap_weight() does not access out-of-bound memory.
2564 */
2565 tmp_cbm = d->new_ctrl;
2566 if (bitmap_weight(&tmp_cbm, r->cache.cbm_len) < r->cache.min_cbm_bits) {
2567 rdt_last_cmd_printf("No space on %s:%d\n", r->name, d->id);
2568 return -ENOSPC;
2569 }
2570 d->have_new_ctrl = true;
2571
2572 return 0;
2573}
2574
2575/*
2576 * Initialize cache resources with default values.
2577 *
2578 * A new RDT group is being created on an allocation capable (CAT)
2579 * supporting system. Set this group up to start off with all usable
2580 * allocations.
2581 *
2582 * If there are no more shareable bits available on any domain then
2583 * the entire allocation will fail.
2584 */
2585static int rdtgroup_init_cat(struct rdt_resource *r, u32 closid)
2586{
2587 struct rdt_domain *d;
2588 int ret;
2589
2590 list_for_each_entry(d, &r->domains, list) {
2591 ret = __init_one_rdt_domain(d, r, closid);
2592 if (ret < 0)
2593 return ret;
2594 }
2595
2596 return 0;
2597}
2598
2599/* Initialize MBA resource with default values. */
2600static void rdtgroup_init_mba(struct rdt_resource *r)
2601{
2602 struct rdt_domain *d;
2603
2604 list_for_each_entry(d, &r->domains, list) {
2605 d->new_ctrl = is_mba_sc(r) ? MBA_MAX_MBPS : r->default_ctrl;
2606 d->have_new_ctrl = true;
2607 }
2608}
2609
2610/* Initialize the RDT group's allocations. */
2611static int rdtgroup_init_alloc(struct rdtgroup *rdtgrp)
2612{
2613 struct rdt_resource *r;
2614 int ret;
2615
2616 for_each_alloc_enabled_rdt_resource(r) {
2617 if (r->rid == RDT_RESOURCE_MBA) {
2618 rdtgroup_init_mba(r);
2619 } else {
2620 ret = rdtgroup_init_cat(r, rdtgrp->closid);
2621 if (ret < 0)
2622 return ret;
2623 }
2624
2625 ret = update_domains(r, rdtgrp->closid);
2626 if (ret < 0) {
2627 rdt_last_cmd_puts("Failed to initialize allocations\n");
2628 return ret;
2629 }
2630
2631 }
2632
2633 rdtgrp->mode = RDT_MODE_SHAREABLE;
2634
2635 return 0;
2636}
2637
2638static int mkdir_rdt_prepare(struct kernfs_node *parent_kn,
2639 struct kernfs_node *prgrp_kn,
2640 const char *name, umode_t mode,
2641 enum rdt_group_type rtype, struct rdtgroup **r)
2642{
2643 struct rdtgroup *prdtgrp, *rdtgrp;
2644 struct kernfs_node *kn;
2645 uint files = 0;
2646 int ret;
2647
2648 prdtgrp = rdtgroup_kn_lock_live(prgrp_kn);
2649 if (!prdtgrp) {
2650 ret = -ENODEV;
2651 goto out_unlock;
2652 }
2653
2654 if (rtype == RDTMON_GROUP &&
2655 (prdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP ||
2656 prdtgrp->mode == RDT_MODE_PSEUDO_LOCKED)) {
2657 ret = -EINVAL;
2658 rdt_last_cmd_puts("Pseudo-locking in progress\n");
2659 goto out_unlock;
2660 }
2661
2662 /* allocate the rdtgroup. */
2663 rdtgrp = kzalloc(sizeof(*rdtgrp), GFP_KERNEL);
2664 if (!rdtgrp) {
2665 ret = -ENOSPC;
2666 rdt_last_cmd_puts("Kernel out of memory\n");
2667 goto out_unlock;
2668 }
2669 *r = rdtgrp;
2670 rdtgrp->mon.parent = prdtgrp;
2671 rdtgrp->type = rtype;
2672 INIT_LIST_HEAD(&rdtgrp->mon.crdtgrp_list);
2673
2674 /* kernfs creates the directory for rdtgrp */
2675 kn = kernfs_create_dir(parent_kn, name, mode, rdtgrp);
2676 if (IS_ERR(kn)) {
2677 ret = PTR_ERR(kn);
2678 rdt_last_cmd_puts("kernfs create error\n");
2679 goto out_free_rgrp;
2680 }
2681 rdtgrp->kn = kn;
2682
2683 /*
2684 * kernfs_remove() will drop the reference count on "kn" which
2685 * will free it. But we still need it to stick around for the
2686 * rdtgroup_kn_unlock(kn} call below. Take one extra reference
2687 * here, which will be dropped inside rdtgroup_kn_unlock().
2688 */
2689 kernfs_get(kn);
2690
2691 ret = rdtgroup_kn_set_ugid(kn);
2692 if (ret) {
2693 rdt_last_cmd_puts("kernfs perm error\n");
2694 goto out_destroy;
2695 }
2696
2697 files = RFTYPE_BASE | BIT(RF_CTRLSHIFT + rtype);
2698 ret = rdtgroup_add_files(kn, files);
2699 if (ret) {
2700 rdt_last_cmd_puts("kernfs fill error\n");
2701 goto out_destroy;
2702 }
2703
2704 if (rdt_mon_capable) {
2705 ret = alloc_rmid();
2706 if (ret < 0) {
2707 rdt_last_cmd_puts("Out of RMIDs\n");
2708 goto out_destroy;
2709 }
2710 rdtgrp->mon.rmid = ret;
2711
2712 ret = mkdir_mondata_all(kn, rdtgrp, &rdtgrp->mon.mon_data_kn);
2713 if (ret) {
2714 rdt_last_cmd_puts("kernfs subdir error\n");
2715 goto out_idfree;
2716 }
2717 }
2718 kernfs_activate(kn);
2719
2720 /*
2721 * The caller unlocks the prgrp_kn upon success.
2722 */
2723 return 0;
2724
2725out_idfree:
2726 free_rmid(rdtgrp->mon.rmid);
2727out_destroy:
2728 kernfs_remove(rdtgrp->kn);
2729out_free_rgrp:
2730 kfree(rdtgrp);
2731out_unlock:
2732 rdtgroup_kn_unlock(prgrp_kn);
2733 return ret;
2734}
2735
2736static void mkdir_rdt_prepare_clean(struct rdtgroup *rgrp)
2737{
2738 kernfs_remove(rgrp->kn);
2739 free_rmid(rgrp->mon.rmid);
2740 kfree(rgrp);
2741}
2742
2743/*
2744 * Create a monitor group under "mon_groups" directory of a control
2745 * and monitor group(ctrl_mon). This is a resource group
2746 * to monitor a subset of tasks and cpus in its parent ctrl_mon group.
2747 */
2748static int rdtgroup_mkdir_mon(struct kernfs_node *parent_kn,
2749 struct kernfs_node *prgrp_kn,
2750 const char *name,
2751 umode_t mode)
2752{
2753 struct rdtgroup *rdtgrp, *prgrp;
2754 int ret;
2755
2756 ret = mkdir_rdt_prepare(parent_kn, prgrp_kn, name, mode, RDTMON_GROUP,
2757 &rdtgrp);
2758 if (ret)
2759 return ret;
2760
2761 prgrp = rdtgrp->mon.parent;
2762 rdtgrp->closid = prgrp->closid;
2763
2764 /*
2765 * Add the rdtgrp to the list of rdtgrps the parent
2766 * ctrl_mon group has to track.
2767 */
2768 list_add_tail(&rdtgrp->mon.crdtgrp_list, &prgrp->mon.crdtgrp_list);
2769
2770 rdtgroup_kn_unlock(prgrp_kn);
2771 return ret;
2772}
2773
2774/*
2775 * These are rdtgroups created under the root directory. Can be used
2776 * to allocate and monitor resources.
2777 */
2778static int rdtgroup_mkdir_ctrl_mon(struct kernfs_node *parent_kn,
2779 struct kernfs_node *prgrp_kn,
2780 const char *name, umode_t mode)
2781{
2782 struct rdtgroup *rdtgrp;
2783 struct kernfs_node *kn;
2784 u32 closid;
2785 int ret;
2786
2787 ret = mkdir_rdt_prepare(parent_kn, prgrp_kn, name, mode, RDTCTRL_GROUP,
2788 &rdtgrp);
2789 if (ret)
2790 return ret;
2791
2792 kn = rdtgrp->kn;
2793 ret = closid_alloc();
2794 if (ret < 0) {
2795 rdt_last_cmd_puts("Out of CLOSIDs\n");
2796 goto out_common_fail;
2797 }
2798 closid = ret;
2799 ret = 0;
2800
2801 rdtgrp->closid = closid;
2802 ret = rdtgroup_init_alloc(rdtgrp);
2803 if (ret < 0)
2804 goto out_id_free;
2805
2806 list_add(&rdtgrp->rdtgroup_list, &rdt_all_groups);
2807
2808 if (rdt_mon_capable) {
2809 /*
2810 * Create an empty mon_groups directory to hold the subset
2811 * of tasks and cpus to monitor.
2812 */
2813 ret = mongroup_create_dir(kn, NULL, "mon_groups", NULL);
2814 if (ret) {
2815 rdt_last_cmd_puts("kernfs subdir error\n");
2816 goto out_del_list;
2817 }
2818 }
2819
2820 goto out_unlock;
2821
2822out_del_list:
2823 list_del(&rdtgrp->rdtgroup_list);
2824out_id_free:
2825 closid_free(closid);
2826out_common_fail:
2827 mkdir_rdt_prepare_clean(rdtgrp);
2828out_unlock:
2829 rdtgroup_kn_unlock(prgrp_kn);
2830 return ret;
2831}
2832
2833/*
2834 * We allow creating mon groups only with in a directory called "mon_groups"
2835 * which is present in every ctrl_mon group. Check if this is a valid
2836 * "mon_groups" directory.
2837 *
2838 * 1. The directory should be named "mon_groups".
2839 * 2. The mon group itself should "not" be named "mon_groups".
2840 * This makes sure "mon_groups" directory always has a ctrl_mon group
2841 * as parent.
2842 */
2843static bool is_mon_groups(struct kernfs_node *kn, const char *name)
2844{
2845 return (!strcmp(kn->name, "mon_groups") &&
2846 strcmp(name, "mon_groups"));
2847}
2848
2849static int rdtgroup_mkdir(struct kernfs_node *parent_kn, const char *name,
2850 umode_t mode)
2851{
2852 /* Do not accept '\n' to avoid unparsable situation. */
2853 if (strchr(name, '\n'))
2854 return -EINVAL;
2855
2856 /*
2857 * If the parent directory is the root directory and RDT
2858 * allocation is supported, add a control and monitoring
2859 * subdirectory
2860 */
2861 if (rdt_alloc_capable && parent_kn == rdtgroup_default.kn)
2862 return rdtgroup_mkdir_ctrl_mon(parent_kn, parent_kn, name, mode);
2863
2864 /*
2865 * If RDT monitoring is supported and the parent directory is a valid
2866 * "mon_groups" directory, add a monitoring subdirectory.
2867 */
2868 if (rdt_mon_capable && is_mon_groups(parent_kn, name))
2869 return rdtgroup_mkdir_mon(parent_kn, parent_kn->parent, name, mode);
2870
2871 return -EPERM;
2872}
2873
2874static int rdtgroup_rmdir_mon(struct kernfs_node *kn, struct rdtgroup *rdtgrp,
2875 cpumask_var_t tmpmask)
2876{
2877 struct rdtgroup *prdtgrp = rdtgrp->mon.parent;
2878 int cpu;
2879
2880 /* Give any tasks back to the parent group */
2881 rdt_move_group_tasks(rdtgrp, prdtgrp, tmpmask);
2882
2883 /* Update per cpu rmid of the moved CPUs first */
2884 for_each_cpu(cpu, &rdtgrp->cpu_mask)
2885 per_cpu(pqr_state.default_rmid, cpu) = prdtgrp->mon.rmid;
2886 /*
2887 * Update the MSR on moved CPUs and CPUs which have moved
2888 * task running on them.
2889 */
2890 cpumask_or(tmpmask, tmpmask, &rdtgrp->cpu_mask);
2891 update_closid_rmid(tmpmask, NULL);
2892
2893 rdtgrp->flags = RDT_DELETED;
2894 free_rmid(rdtgrp->mon.rmid);
2895
2896 /*
2897 * Remove the rdtgrp from the parent ctrl_mon group's list
2898 */
2899 WARN_ON(list_empty(&prdtgrp->mon.crdtgrp_list));
2900 list_del(&rdtgrp->mon.crdtgrp_list);
2901
2902 /*
2903 * one extra hold on this, will drop when we kfree(rdtgrp)
2904 * in rdtgroup_kn_unlock()
2905 */
2906 kernfs_get(kn);
2907 kernfs_remove(rdtgrp->kn);
2908
2909 return 0;
2910}
2911
2912static int rdtgroup_ctrl_remove(struct kernfs_node *kn,
2913 struct rdtgroup *rdtgrp)
2914{
2915 rdtgrp->flags = RDT_DELETED;
2916 list_del(&rdtgrp->rdtgroup_list);
2917
2918 /*
2919 * one extra hold on this, will drop when we kfree(rdtgrp)
2920 * in rdtgroup_kn_unlock()
2921 */
2922 kernfs_get(kn);
2923 kernfs_remove(rdtgrp->kn);
2924 return 0;
2925}
2926
2927static int rdtgroup_rmdir_ctrl(struct kernfs_node *kn, struct rdtgroup *rdtgrp,
2928 cpumask_var_t tmpmask)
2929{
2930 int cpu;
2931
2932 /* Give any tasks back to the default group */
2933 rdt_move_group_tasks(rdtgrp, &rdtgroup_default, tmpmask);
2934
2935 /* Give any CPUs back to the default group */
2936 cpumask_or(&rdtgroup_default.cpu_mask,
2937 &rdtgroup_default.cpu_mask, &rdtgrp->cpu_mask);
2938
2939 /* Update per cpu closid and rmid of the moved CPUs first */
2940 for_each_cpu(cpu, &rdtgrp->cpu_mask) {
2941 per_cpu(pqr_state.default_closid, cpu) = rdtgroup_default.closid;
2942 per_cpu(pqr_state.default_rmid, cpu) = rdtgroup_default.mon.rmid;
2943 }
2944
2945 /*
2946 * Update the MSR on moved CPUs and CPUs which have moved
2947 * task running on them.
2948 */
2949 cpumask_or(tmpmask, tmpmask, &rdtgrp->cpu_mask);
2950 update_closid_rmid(tmpmask, NULL);
2951
2952 closid_free(rdtgrp->closid);
2953 free_rmid(rdtgrp->mon.rmid);
2954
2955 /*
2956 * Free all the child monitor group rmids.
2957 */
2958 free_all_child_rdtgrp(rdtgrp);
2959
2960 rdtgroup_ctrl_remove(kn, rdtgrp);
2961
2962 return 0;
2963}
2964
2965static int rdtgroup_rmdir(struct kernfs_node *kn)
2966{
2967 struct kernfs_node *parent_kn = kn->parent;
2968 struct rdtgroup *rdtgrp;
2969 cpumask_var_t tmpmask;
2970 int ret = 0;
2971
2972 if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL))
2973 return -ENOMEM;
2974
2975 rdtgrp = rdtgroup_kn_lock_live(kn);
2976 if (!rdtgrp) {
2977 ret = -EPERM;
2978 goto out;
2979 }
2980
2981 /*
2982 * If the rdtgroup is a ctrl_mon group and parent directory
2983 * is the root directory, remove the ctrl_mon group.
2984 *
2985 * If the rdtgroup is a mon group and parent directory
2986 * is a valid "mon_groups" directory, remove the mon group.
2987 */
2988 if (rdtgrp->type == RDTCTRL_GROUP && parent_kn == rdtgroup_default.kn) {
2989 if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP ||
2990 rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
2991 ret = rdtgroup_ctrl_remove(kn, rdtgrp);
2992 } else {
2993 ret = rdtgroup_rmdir_ctrl(kn, rdtgrp, tmpmask);
2994 }
2995 } else if (rdtgrp->type == RDTMON_GROUP &&
2996 is_mon_groups(parent_kn, kn->name)) {
2997 ret = rdtgroup_rmdir_mon(kn, rdtgrp, tmpmask);
2998 } else {
2999 ret = -EPERM;
3000 }
3001
3002out:
3003 rdtgroup_kn_unlock(kn);
3004 free_cpumask_var(tmpmask);
3005 return ret;
3006}
3007
3008static int rdtgroup_show_options(struct seq_file *seq, struct kernfs_root *kf)
3009{
3010 if (rdt_resources_all[RDT_RESOURCE_L3DATA].alloc_enabled)
3011 seq_puts(seq, ",cdp");
3012
3013 if (rdt_resources_all[RDT_RESOURCE_L2DATA].alloc_enabled)
3014 seq_puts(seq, ",cdpl2");
3015
3016 if (is_mba_sc(&rdt_resources_all[RDT_RESOURCE_MBA]))
3017 seq_puts(seq, ",mba_MBps");
3018
3019 return 0;
3020}
3021
3022static struct kernfs_syscall_ops rdtgroup_kf_syscall_ops = {
3023 .mkdir = rdtgroup_mkdir,
3024 .rmdir = rdtgroup_rmdir,
3025 .show_options = rdtgroup_show_options,
3026};
3027
3028static int __init rdtgroup_setup_root(void)
3029{
3030 int ret;
3031
3032 rdt_root = kernfs_create_root(&rdtgroup_kf_syscall_ops,
3033 KERNFS_ROOT_CREATE_DEACTIVATED |
3034 KERNFS_ROOT_EXTRA_OPEN_PERM_CHECK,
3035 &rdtgroup_default);
3036 if (IS_ERR(rdt_root))
3037 return PTR_ERR(rdt_root);
3038
3039 mutex_lock(&rdtgroup_mutex);
3040
3041 rdtgroup_default.closid = 0;
3042 rdtgroup_default.mon.rmid = 0;
3043 rdtgroup_default.type = RDTCTRL_GROUP;
3044 INIT_LIST_HEAD(&rdtgroup_default.mon.crdtgrp_list);
3045
3046 list_add(&rdtgroup_default.rdtgroup_list, &rdt_all_groups);
3047
3048 ret = rdtgroup_add_files(rdt_root->kn, RF_CTRL_BASE);
3049 if (ret) {
3050 kernfs_destroy_root(rdt_root);
3051 goto out;
3052 }
3053
3054 rdtgroup_default.kn = rdt_root->kn;
3055 kernfs_activate(rdtgroup_default.kn);
3056
3057out:
3058 mutex_unlock(&rdtgroup_mutex);
3059
3060 return ret;
3061}
3062
3063/*
3064 * rdtgroup_init - rdtgroup initialization
3065 *
3066 * Setup resctrl file system including set up root, create mount point,
3067 * register rdtgroup filesystem, and initialize files under root directory.
3068 *
3069 * Return: 0 on success or -errno
3070 */
3071int __init rdtgroup_init(void)
3072{
3073 int ret = 0;
3074
3075 seq_buf_init(&last_cmd_status, last_cmd_status_buf,
3076 sizeof(last_cmd_status_buf));
3077
3078 ret = rdtgroup_setup_root();
3079 if (ret)
3080 return ret;
3081
3082 ret = sysfs_create_mount_point(fs_kobj, "resctrl");
3083 if (ret)
3084 goto cleanup_root;
3085
3086 ret = register_filesystem(&rdt_fs_type);
3087 if (ret)
3088 goto cleanup_mountpoint;
3089
3090 /*
3091 * Adding the resctrl debugfs directory here may not be ideal since
3092 * it would let the resctrl debugfs directory appear on the debugfs
3093 * filesystem before the resctrl filesystem is mounted.
3094 * It may also be ok since that would enable debugging of RDT before
3095 * resctrl is mounted.
3096 * The reason why the debugfs directory is created here and not in
3097 * rdt_mount() is because rdt_mount() takes rdtgroup_mutex and
3098 * during the debugfs directory creation also &sb->s_type->i_mutex_key
3099 * (the lockdep class of inode->i_rwsem). Other filesystem
3100 * interactions (eg. SyS_getdents) have the lock ordering:
3101 * &sb->s_type->i_mutex_key --> &mm->mmap_sem
3102 * During mmap(), called with &mm->mmap_sem, the rdtgroup_mutex
3103 * is taken, thus creating dependency:
3104 * &mm->mmap_sem --> rdtgroup_mutex for the latter that can cause
3105 * issues considering the other two lock dependencies.
3106 * By creating the debugfs directory here we avoid a dependency
3107 * that may cause deadlock (even though file operations cannot
3108 * occur until the filesystem is mounted, but I do not know how to
3109 * tell lockdep that).
3110 */
3111 debugfs_resctrl = debugfs_create_dir("resctrl", NULL);
3112
3113 return 0;
3114
3115cleanup_mountpoint:
3116 sysfs_remove_mount_point(fs_kobj, "resctrl");
3117cleanup_root:
3118 kernfs_destroy_root(rdt_root);
3119
3120 return ret;
3121}
3122
3123void __exit rdtgroup_exit(void)
3124{
3125 debugfs_remove_recursive(debugfs_resctrl);
3126 unregister_filesystem(&rdt_fs_type);
3127 sysfs_remove_mount_point(fs_kobj, "resctrl");
3128 kernfs_destroy_root(rdt_root);
3129}
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * User interface for Resource Allocation in Resource Director Technology(RDT)
4 *
5 * Copyright (C) 2016 Intel Corporation
6 *
7 * Author: Fenghua Yu <fenghua.yu@intel.com>
8 *
9 * More information about RDT be found in the Intel (R) x86 Architecture
10 * Software Developer Manual.
11 */
12
13#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14
15#include <linux/cacheinfo.h>
16#include <linux/cpu.h>
17#include <linux/debugfs.h>
18#include <linux/fs.h>
19#include <linux/fs_parser.h>
20#include <linux/sysfs.h>
21#include <linux/kernfs.h>
22#include <linux/seq_buf.h>
23#include <linux/seq_file.h>
24#include <linux/sched/signal.h>
25#include <linux/sched/task.h>
26#include <linux/slab.h>
27#include <linux/task_work.h>
28#include <linux/user_namespace.h>
29
30#include <uapi/linux/magic.h>
31
32#include <asm/resctrl.h>
33#include "internal.h"
34
35DEFINE_STATIC_KEY_FALSE(rdt_enable_key);
36DEFINE_STATIC_KEY_FALSE(rdt_mon_enable_key);
37DEFINE_STATIC_KEY_FALSE(rdt_alloc_enable_key);
38static struct kernfs_root *rdt_root;
39struct rdtgroup rdtgroup_default;
40LIST_HEAD(rdt_all_groups);
41
42/* Kernel fs node for "info" directory under root */
43static struct kernfs_node *kn_info;
44
45/* Kernel fs node for "mon_groups" directory under root */
46static struct kernfs_node *kn_mongrp;
47
48/* Kernel fs node for "mon_data" directory under root */
49static struct kernfs_node *kn_mondata;
50
51static struct seq_buf last_cmd_status;
52static char last_cmd_status_buf[512];
53
54struct dentry *debugfs_resctrl;
55
56void rdt_last_cmd_clear(void)
57{
58 lockdep_assert_held(&rdtgroup_mutex);
59 seq_buf_clear(&last_cmd_status);
60}
61
62void rdt_last_cmd_puts(const char *s)
63{
64 lockdep_assert_held(&rdtgroup_mutex);
65 seq_buf_puts(&last_cmd_status, s);
66}
67
68void rdt_last_cmd_printf(const char *fmt, ...)
69{
70 va_list ap;
71
72 va_start(ap, fmt);
73 lockdep_assert_held(&rdtgroup_mutex);
74 seq_buf_vprintf(&last_cmd_status, fmt, ap);
75 va_end(ap);
76}
77
78/*
79 * Trivial allocator for CLOSIDs. Since h/w only supports a small number,
80 * we can keep a bitmap of free CLOSIDs in a single integer.
81 *
82 * Using a global CLOSID across all resources has some advantages and
83 * some drawbacks:
84 * + We can simply set "current->closid" to assign a task to a resource
85 * group.
86 * + Context switch code can avoid extra memory references deciding which
87 * CLOSID to load into the PQR_ASSOC MSR
88 * - We give up some options in configuring resource groups across multi-socket
89 * systems.
90 * - Our choices on how to configure each resource become progressively more
91 * limited as the number of resources grows.
92 */
93static int closid_free_map;
94static int closid_free_map_len;
95
96int closids_supported(void)
97{
98 return closid_free_map_len;
99}
100
101static void closid_init(void)
102{
103 struct rdt_resource *r;
104 int rdt_min_closid = 32;
105
106 /* Compute rdt_min_closid across all resources */
107 for_each_alloc_enabled_rdt_resource(r)
108 rdt_min_closid = min(rdt_min_closid, r->num_closid);
109
110 closid_free_map = BIT_MASK(rdt_min_closid) - 1;
111
112 /* CLOSID 0 is always reserved for the default group */
113 closid_free_map &= ~1;
114 closid_free_map_len = rdt_min_closid;
115}
116
117static int closid_alloc(void)
118{
119 u32 closid = ffs(closid_free_map);
120
121 if (closid == 0)
122 return -ENOSPC;
123 closid--;
124 closid_free_map &= ~(1 << closid);
125
126 return closid;
127}
128
129void closid_free(int closid)
130{
131 closid_free_map |= 1 << closid;
132}
133
134/**
135 * closid_allocated - test if provided closid is in use
136 * @closid: closid to be tested
137 *
138 * Return: true if @closid is currently associated with a resource group,
139 * false if @closid is free
140 */
141static bool closid_allocated(unsigned int closid)
142{
143 return (closid_free_map & (1 << closid)) == 0;
144}
145
146/**
147 * rdtgroup_mode_by_closid - Return mode of resource group with closid
148 * @closid: closid if the resource group
149 *
150 * Each resource group is associated with a @closid. Here the mode
151 * of a resource group can be queried by searching for it using its closid.
152 *
153 * Return: mode as &enum rdtgrp_mode of resource group with closid @closid
154 */
155enum rdtgrp_mode rdtgroup_mode_by_closid(int closid)
156{
157 struct rdtgroup *rdtgrp;
158
159 list_for_each_entry(rdtgrp, &rdt_all_groups, rdtgroup_list) {
160 if (rdtgrp->closid == closid)
161 return rdtgrp->mode;
162 }
163
164 return RDT_NUM_MODES;
165}
166
167static const char * const rdt_mode_str[] = {
168 [RDT_MODE_SHAREABLE] = "shareable",
169 [RDT_MODE_EXCLUSIVE] = "exclusive",
170 [RDT_MODE_PSEUDO_LOCKSETUP] = "pseudo-locksetup",
171 [RDT_MODE_PSEUDO_LOCKED] = "pseudo-locked",
172};
173
174/**
175 * rdtgroup_mode_str - Return the string representation of mode
176 * @mode: the resource group mode as &enum rdtgroup_mode
177 *
178 * Return: string representation of valid mode, "unknown" otherwise
179 */
180static const char *rdtgroup_mode_str(enum rdtgrp_mode mode)
181{
182 if (mode < RDT_MODE_SHAREABLE || mode >= RDT_NUM_MODES)
183 return "unknown";
184
185 return rdt_mode_str[mode];
186}
187
188/* set uid and gid of rdtgroup dirs and files to that of the creator */
189static int rdtgroup_kn_set_ugid(struct kernfs_node *kn)
190{
191 struct iattr iattr = { .ia_valid = ATTR_UID | ATTR_GID,
192 .ia_uid = current_fsuid(),
193 .ia_gid = current_fsgid(), };
194
195 if (uid_eq(iattr.ia_uid, GLOBAL_ROOT_UID) &&
196 gid_eq(iattr.ia_gid, GLOBAL_ROOT_GID))
197 return 0;
198
199 return kernfs_setattr(kn, &iattr);
200}
201
202static int rdtgroup_add_file(struct kernfs_node *parent_kn, struct rftype *rft)
203{
204 struct kernfs_node *kn;
205 int ret;
206
207 kn = __kernfs_create_file(parent_kn, rft->name, rft->mode,
208 GLOBAL_ROOT_UID, GLOBAL_ROOT_GID,
209 0, rft->kf_ops, rft, NULL, NULL);
210 if (IS_ERR(kn))
211 return PTR_ERR(kn);
212
213 ret = rdtgroup_kn_set_ugid(kn);
214 if (ret) {
215 kernfs_remove(kn);
216 return ret;
217 }
218
219 return 0;
220}
221
222static int rdtgroup_seqfile_show(struct seq_file *m, void *arg)
223{
224 struct kernfs_open_file *of = m->private;
225 struct rftype *rft = of->kn->priv;
226
227 if (rft->seq_show)
228 return rft->seq_show(of, m, arg);
229 return 0;
230}
231
232static ssize_t rdtgroup_file_write(struct kernfs_open_file *of, char *buf,
233 size_t nbytes, loff_t off)
234{
235 struct rftype *rft = of->kn->priv;
236
237 if (rft->write)
238 return rft->write(of, buf, nbytes, off);
239
240 return -EINVAL;
241}
242
243static const struct kernfs_ops rdtgroup_kf_single_ops = {
244 .atomic_write_len = PAGE_SIZE,
245 .write = rdtgroup_file_write,
246 .seq_show = rdtgroup_seqfile_show,
247};
248
249static const struct kernfs_ops kf_mondata_ops = {
250 .atomic_write_len = PAGE_SIZE,
251 .seq_show = rdtgroup_mondata_show,
252};
253
254static bool is_cpu_list(struct kernfs_open_file *of)
255{
256 struct rftype *rft = of->kn->priv;
257
258 return rft->flags & RFTYPE_FLAGS_CPUS_LIST;
259}
260
261static int rdtgroup_cpus_show(struct kernfs_open_file *of,
262 struct seq_file *s, void *v)
263{
264 struct rdtgroup *rdtgrp;
265 struct cpumask *mask;
266 int ret = 0;
267
268 rdtgrp = rdtgroup_kn_lock_live(of->kn);
269
270 if (rdtgrp) {
271 if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
272 if (!rdtgrp->plr->d) {
273 rdt_last_cmd_clear();
274 rdt_last_cmd_puts("Cache domain offline\n");
275 ret = -ENODEV;
276 } else {
277 mask = &rdtgrp->plr->d->cpu_mask;
278 seq_printf(s, is_cpu_list(of) ?
279 "%*pbl\n" : "%*pb\n",
280 cpumask_pr_args(mask));
281 }
282 } else {
283 seq_printf(s, is_cpu_list(of) ? "%*pbl\n" : "%*pb\n",
284 cpumask_pr_args(&rdtgrp->cpu_mask));
285 }
286 } else {
287 ret = -ENOENT;
288 }
289 rdtgroup_kn_unlock(of->kn);
290
291 return ret;
292}
293
294/*
295 * This is safe against resctrl_sched_in() called from __switch_to()
296 * because __switch_to() is executed with interrupts disabled. A local call
297 * from update_closid_rmid() is protected against __switch_to() because
298 * preemption is disabled.
299 */
300static void update_cpu_closid_rmid(void *info)
301{
302 struct rdtgroup *r = info;
303
304 if (r) {
305 this_cpu_write(pqr_state.default_closid, r->closid);
306 this_cpu_write(pqr_state.default_rmid, r->mon.rmid);
307 }
308
309 /*
310 * We cannot unconditionally write the MSR because the current
311 * executing task might have its own closid selected. Just reuse
312 * the context switch code.
313 */
314 resctrl_sched_in();
315}
316
317/*
318 * Update the PGR_ASSOC MSR on all cpus in @cpu_mask,
319 *
320 * Per task closids/rmids must have been set up before calling this function.
321 */
322static void
323update_closid_rmid(const struct cpumask *cpu_mask, struct rdtgroup *r)
324{
325 int cpu = get_cpu();
326
327 if (cpumask_test_cpu(cpu, cpu_mask))
328 update_cpu_closid_rmid(r);
329 smp_call_function_many(cpu_mask, update_cpu_closid_rmid, r, 1);
330 put_cpu();
331}
332
333static int cpus_mon_write(struct rdtgroup *rdtgrp, cpumask_var_t newmask,
334 cpumask_var_t tmpmask)
335{
336 struct rdtgroup *prgrp = rdtgrp->mon.parent, *crgrp;
337 struct list_head *head;
338
339 /* Check whether cpus belong to parent ctrl group */
340 cpumask_andnot(tmpmask, newmask, &prgrp->cpu_mask);
341 if (cpumask_weight(tmpmask)) {
342 rdt_last_cmd_puts("Can only add CPUs to mongroup that belong to parent\n");
343 return -EINVAL;
344 }
345
346 /* Check whether cpus are dropped from this group */
347 cpumask_andnot(tmpmask, &rdtgrp->cpu_mask, newmask);
348 if (cpumask_weight(tmpmask)) {
349 /* Give any dropped cpus to parent rdtgroup */
350 cpumask_or(&prgrp->cpu_mask, &prgrp->cpu_mask, tmpmask);
351 update_closid_rmid(tmpmask, prgrp);
352 }
353
354 /*
355 * If we added cpus, remove them from previous group that owned them
356 * and update per-cpu rmid
357 */
358 cpumask_andnot(tmpmask, newmask, &rdtgrp->cpu_mask);
359 if (cpumask_weight(tmpmask)) {
360 head = &prgrp->mon.crdtgrp_list;
361 list_for_each_entry(crgrp, head, mon.crdtgrp_list) {
362 if (crgrp == rdtgrp)
363 continue;
364 cpumask_andnot(&crgrp->cpu_mask, &crgrp->cpu_mask,
365 tmpmask);
366 }
367 update_closid_rmid(tmpmask, rdtgrp);
368 }
369
370 /* Done pushing/pulling - update this group with new mask */
371 cpumask_copy(&rdtgrp->cpu_mask, newmask);
372
373 return 0;
374}
375
376static void cpumask_rdtgrp_clear(struct rdtgroup *r, struct cpumask *m)
377{
378 struct rdtgroup *crgrp;
379
380 cpumask_andnot(&r->cpu_mask, &r->cpu_mask, m);
381 /* update the child mon group masks as well*/
382 list_for_each_entry(crgrp, &r->mon.crdtgrp_list, mon.crdtgrp_list)
383 cpumask_and(&crgrp->cpu_mask, &r->cpu_mask, &crgrp->cpu_mask);
384}
385
386static int cpus_ctrl_write(struct rdtgroup *rdtgrp, cpumask_var_t newmask,
387 cpumask_var_t tmpmask, cpumask_var_t tmpmask1)
388{
389 struct rdtgroup *r, *crgrp;
390 struct list_head *head;
391
392 /* Check whether cpus are dropped from this group */
393 cpumask_andnot(tmpmask, &rdtgrp->cpu_mask, newmask);
394 if (cpumask_weight(tmpmask)) {
395 /* Can't drop from default group */
396 if (rdtgrp == &rdtgroup_default) {
397 rdt_last_cmd_puts("Can't drop CPUs from default group\n");
398 return -EINVAL;
399 }
400
401 /* Give any dropped cpus to rdtgroup_default */
402 cpumask_or(&rdtgroup_default.cpu_mask,
403 &rdtgroup_default.cpu_mask, tmpmask);
404 update_closid_rmid(tmpmask, &rdtgroup_default);
405 }
406
407 /*
408 * If we added cpus, remove them from previous group and
409 * the prev group's child groups that owned them
410 * and update per-cpu closid/rmid.
411 */
412 cpumask_andnot(tmpmask, newmask, &rdtgrp->cpu_mask);
413 if (cpumask_weight(tmpmask)) {
414 list_for_each_entry(r, &rdt_all_groups, rdtgroup_list) {
415 if (r == rdtgrp)
416 continue;
417 cpumask_and(tmpmask1, &r->cpu_mask, tmpmask);
418 if (cpumask_weight(tmpmask1))
419 cpumask_rdtgrp_clear(r, tmpmask1);
420 }
421 update_closid_rmid(tmpmask, rdtgrp);
422 }
423
424 /* Done pushing/pulling - update this group with new mask */
425 cpumask_copy(&rdtgrp->cpu_mask, newmask);
426
427 /*
428 * Clear child mon group masks since there is a new parent mask
429 * now and update the rmid for the cpus the child lost.
430 */
431 head = &rdtgrp->mon.crdtgrp_list;
432 list_for_each_entry(crgrp, head, mon.crdtgrp_list) {
433 cpumask_and(tmpmask, &rdtgrp->cpu_mask, &crgrp->cpu_mask);
434 update_closid_rmid(tmpmask, rdtgrp);
435 cpumask_clear(&crgrp->cpu_mask);
436 }
437
438 return 0;
439}
440
441static ssize_t rdtgroup_cpus_write(struct kernfs_open_file *of,
442 char *buf, size_t nbytes, loff_t off)
443{
444 cpumask_var_t tmpmask, newmask, tmpmask1;
445 struct rdtgroup *rdtgrp;
446 int ret;
447
448 if (!buf)
449 return -EINVAL;
450
451 if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL))
452 return -ENOMEM;
453 if (!zalloc_cpumask_var(&newmask, GFP_KERNEL)) {
454 free_cpumask_var(tmpmask);
455 return -ENOMEM;
456 }
457 if (!zalloc_cpumask_var(&tmpmask1, GFP_KERNEL)) {
458 free_cpumask_var(tmpmask);
459 free_cpumask_var(newmask);
460 return -ENOMEM;
461 }
462
463 rdtgrp = rdtgroup_kn_lock_live(of->kn);
464 if (!rdtgrp) {
465 ret = -ENOENT;
466 goto unlock;
467 }
468
469 if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED ||
470 rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
471 ret = -EINVAL;
472 rdt_last_cmd_puts("Pseudo-locking in progress\n");
473 goto unlock;
474 }
475
476 if (is_cpu_list(of))
477 ret = cpulist_parse(buf, newmask);
478 else
479 ret = cpumask_parse(buf, newmask);
480
481 if (ret) {
482 rdt_last_cmd_puts("Bad CPU list/mask\n");
483 goto unlock;
484 }
485
486 /* check that user didn't specify any offline cpus */
487 cpumask_andnot(tmpmask, newmask, cpu_online_mask);
488 if (cpumask_weight(tmpmask)) {
489 ret = -EINVAL;
490 rdt_last_cmd_puts("Can only assign online CPUs\n");
491 goto unlock;
492 }
493
494 if (rdtgrp->type == RDTCTRL_GROUP)
495 ret = cpus_ctrl_write(rdtgrp, newmask, tmpmask, tmpmask1);
496 else if (rdtgrp->type == RDTMON_GROUP)
497 ret = cpus_mon_write(rdtgrp, newmask, tmpmask);
498 else
499 ret = -EINVAL;
500
501unlock:
502 rdtgroup_kn_unlock(of->kn);
503 free_cpumask_var(tmpmask);
504 free_cpumask_var(newmask);
505 free_cpumask_var(tmpmask1);
506
507 return ret ?: nbytes;
508}
509
510/**
511 * rdtgroup_remove - the helper to remove resource group safely
512 * @rdtgrp: resource group to remove
513 *
514 * On resource group creation via a mkdir, an extra kernfs_node reference is
515 * taken to ensure that the rdtgroup structure remains accessible for the
516 * rdtgroup_kn_unlock() calls where it is removed.
517 *
518 * Drop the extra reference here, then free the rdtgroup structure.
519 *
520 * Return: void
521 */
522static void rdtgroup_remove(struct rdtgroup *rdtgrp)
523{
524 kernfs_put(rdtgrp->kn);
525 kfree(rdtgrp);
526}
527
528static void _update_task_closid_rmid(void *task)
529{
530 /*
531 * If the task is still current on this CPU, update PQR_ASSOC MSR.
532 * Otherwise, the MSR is updated when the task is scheduled in.
533 */
534 if (task == current)
535 resctrl_sched_in();
536}
537
538static void update_task_closid_rmid(struct task_struct *t)
539{
540 if (IS_ENABLED(CONFIG_SMP) && task_curr(t))
541 smp_call_function_single(task_cpu(t), _update_task_closid_rmid, t, 1);
542 else
543 _update_task_closid_rmid(t);
544}
545
546static int __rdtgroup_move_task(struct task_struct *tsk,
547 struct rdtgroup *rdtgrp)
548{
549 /* If the task is already in rdtgrp, no need to move the task. */
550 if ((rdtgrp->type == RDTCTRL_GROUP && tsk->closid == rdtgrp->closid &&
551 tsk->rmid == rdtgrp->mon.rmid) ||
552 (rdtgrp->type == RDTMON_GROUP && tsk->rmid == rdtgrp->mon.rmid &&
553 tsk->closid == rdtgrp->mon.parent->closid))
554 return 0;
555
556 /*
557 * Set the task's closid/rmid before the PQR_ASSOC MSR can be
558 * updated by them.
559 *
560 * For ctrl_mon groups, move both closid and rmid.
561 * For monitor groups, can move the tasks only from
562 * their parent CTRL group.
563 */
564
565 if (rdtgrp->type == RDTCTRL_GROUP) {
566 WRITE_ONCE(tsk->closid, rdtgrp->closid);
567 WRITE_ONCE(tsk->rmid, rdtgrp->mon.rmid);
568 } else if (rdtgrp->type == RDTMON_GROUP) {
569 if (rdtgrp->mon.parent->closid == tsk->closid) {
570 WRITE_ONCE(tsk->rmid, rdtgrp->mon.rmid);
571 } else {
572 rdt_last_cmd_puts("Can't move task to different control group\n");
573 return -EINVAL;
574 }
575 }
576
577 /*
578 * Ensure the task's closid and rmid are written before determining if
579 * the task is current that will decide if it will be interrupted.
580 */
581 barrier();
582
583 /*
584 * By now, the task's closid and rmid are set. If the task is current
585 * on a CPU, the PQR_ASSOC MSR needs to be updated to make the resource
586 * group go into effect. If the task is not current, the MSR will be
587 * updated when the task is scheduled in.
588 */
589 update_task_closid_rmid(tsk);
590
591 return 0;
592}
593
594static bool is_closid_match(struct task_struct *t, struct rdtgroup *r)
595{
596 return (rdt_alloc_capable &&
597 (r->type == RDTCTRL_GROUP) && (t->closid == r->closid));
598}
599
600static bool is_rmid_match(struct task_struct *t, struct rdtgroup *r)
601{
602 return (rdt_mon_capable &&
603 (r->type == RDTMON_GROUP) && (t->rmid == r->mon.rmid));
604}
605
606/**
607 * rdtgroup_tasks_assigned - Test if tasks have been assigned to resource group
608 * @r: Resource group
609 *
610 * Return: 1 if tasks have been assigned to @r, 0 otherwise
611 */
612int rdtgroup_tasks_assigned(struct rdtgroup *r)
613{
614 struct task_struct *p, *t;
615 int ret = 0;
616
617 lockdep_assert_held(&rdtgroup_mutex);
618
619 rcu_read_lock();
620 for_each_process_thread(p, t) {
621 if (is_closid_match(t, r) || is_rmid_match(t, r)) {
622 ret = 1;
623 break;
624 }
625 }
626 rcu_read_unlock();
627
628 return ret;
629}
630
631static int rdtgroup_task_write_permission(struct task_struct *task,
632 struct kernfs_open_file *of)
633{
634 const struct cred *tcred = get_task_cred(task);
635 const struct cred *cred = current_cred();
636 int ret = 0;
637
638 /*
639 * Even if we're attaching all tasks in the thread group, we only
640 * need to check permissions on one of them.
641 */
642 if (!uid_eq(cred->euid, GLOBAL_ROOT_UID) &&
643 !uid_eq(cred->euid, tcred->uid) &&
644 !uid_eq(cred->euid, tcred->suid)) {
645 rdt_last_cmd_printf("No permission to move task %d\n", task->pid);
646 ret = -EPERM;
647 }
648
649 put_cred(tcred);
650 return ret;
651}
652
653static int rdtgroup_move_task(pid_t pid, struct rdtgroup *rdtgrp,
654 struct kernfs_open_file *of)
655{
656 struct task_struct *tsk;
657 int ret;
658
659 rcu_read_lock();
660 if (pid) {
661 tsk = find_task_by_vpid(pid);
662 if (!tsk) {
663 rcu_read_unlock();
664 rdt_last_cmd_printf("No task %d\n", pid);
665 return -ESRCH;
666 }
667 } else {
668 tsk = current;
669 }
670
671 get_task_struct(tsk);
672 rcu_read_unlock();
673
674 ret = rdtgroup_task_write_permission(tsk, of);
675 if (!ret)
676 ret = __rdtgroup_move_task(tsk, rdtgrp);
677
678 put_task_struct(tsk);
679 return ret;
680}
681
682static ssize_t rdtgroup_tasks_write(struct kernfs_open_file *of,
683 char *buf, size_t nbytes, loff_t off)
684{
685 struct rdtgroup *rdtgrp;
686 int ret = 0;
687 pid_t pid;
688
689 if (kstrtoint(strstrip(buf), 0, &pid) || pid < 0)
690 return -EINVAL;
691 rdtgrp = rdtgroup_kn_lock_live(of->kn);
692 if (!rdtgrp) {
693 rdtgroup_kn_unlock(of->kn);
694 return -ENOENT;
695 }
696 rdt_last_cmd_clear();
697
698 if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED ||
699 rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
700 ret = -EINVAL;
701 rdt_last_cmd_puts("Pseudo-locking in progress\n");
702 goto unlock;
703 }
704
705 ret = rdtgroup_move_task(pid, rdtgrp, of);
706
707unlock:
708 rdtgroup_kn_unlock(of->kn);
709
710 return ret ?: nbytes;
711}
712
713static void show_rdt_tasks(struct rdtgroup *r, struct seq_file *s)
714{
715 struct task_struct *p, *t;
716
717 rcu_read_lock();
718 for_each_process_thread(p, t) {
719 if (is_closid_match(t, r) || is_rmid_match(t, r))
720 seq_printf(s, "%d\n", t->pid);
721 }
722 rcu_read_unlock();
723}
724
725static int rdtgroup_tasks_show(struct kernfs_open_file *of,
726 struct seq_file *s, void *v)
727{
728 struct rdtgroup *rdtgrp;
729 int ret = 0;
730
731 rdtgrp = rdtgroup_kn_lock_live(of->kn);
732 if (rdtgrp)
733 show_rdt_tasks(rdtgrp, s);
734 else
735 ret = -ENOENT;
736 rdtgroup_kn_unlock(of->kn);
737
738 return ret;
739}
740
741#ifdef CONFIG_PROC_CPU_RESCTRL
742
743/*
744 * A task can only be part of one resctrl control group and of one monitor
745 * group which is associated to that control group.
746 *
747 * 1) res:
748 * mon:
749 *
750 * resctrl is not available.
751 *
752 * 2) res:/
753 * mon:
754 *
755 * Task is part of the root resctrl control group, and it is not associated
756 * to any monitor group.
757 *
758 * 3) res:/
759 * mon:mon0
760 *
761 * Task is part of the root resctrl control group and monitor group mon0.
762 *
763 * 4) res:group0
764 * mon:
765 *
766 * Task is part of resctrl control group group0, and it is not associated
767 * to any monitor group.
768 *
769 * 5) res:group0
770 * mon:mon1
771 *
772 * Task is part of resctrl control group group0 and monitor group mon1.
773 */
774int proc_resctrl_show(struct seq_file *s, struct pid_namespace *ns,
775 struct pid *pid, struct task_struct *tsk)
776{
777 struct rdtgroup *rdtg;
778 int ret = 0;
779
780 mutex_lock(&rdtgroup_mutex);
781
782 /* Return empty if resctrl has not been mounted. */
783 if (!static_branch_unlikely(&rdt_enable_key)) {
784 seq_puts(s, "res:\nmon:\n");
785 goto unlock;
786 }
787
788 list_for_each_entry(rdtg, &rdt_all_groups, rdtgroup_list) {
789 struct rdtgroup *crg;
790
791 /*
792 * Task information is only relevant for shareable
793 * and exclusive groups.
794 */
795 if (rdtg->mode != RDT_MODE_SHAREABLE &&
796 rdtg->mode != RDT_MODE_EXCLUSIVE)
797 continue;
798
799 if (rdtg->closid != tsk->closid)
800 continue;
801
802 seq_printf(s, "res:%s%s\n", (rdtg == &rdtgroup_default) ? "/" : "",
803 rdtg->kn->name);
804 seq_puts(s, "mon:");
805 list_for_each_entry(crg, &rdtg->mon.crdtgrp_list,
806 mon.crdtgrp_list) {
807 if (tsk->rmid != crg->mon.rmid)
808 continue;
809 seq_printf(s, "%s", crg->kn->name);
810 break;
811 }
812 seq_putc(s, '\n');
813 goto unlock;
814 }
815 /*
816 * The above search should succeed. Otherwise return
817 * with an error.
818 */
819 ret = -ENOENT;
820unlock:
821 mutex_unlock(&rdtgroup_mutex);
822
823 return ret;
824}
825#endif
826
827static int rdt_last_cmd_status_show(struct kernfs_open_file *of,
828 struct seq_file *seq, void *v)
829{
830 int len;
831
832 mutex_lock(&rdtgroup_mutex);
833 len = seq_buf_used(&last_cmd_status);
834 if (len)
835 seq_printf(seq, "%.*s", len, last_cmd_status_buf);
836 else
837 seq_puts(seq, "ok\n");
838 mutex_unlock(&rdtgroup_mutex);
839 return 0;
840}
841
842static int rdt_num_closids_show(struct kernfs_open_file *of,
843 struct seq_file *seq, void *v)
844{
845 struct rdt_resource *r = of->kn->parent->priv;
846
847 seq_printf(seq, "%d\n", r->num_closid);
848 return 0;
849}
850
851static int rdt_default_ctrl_show(struct kernfs_open_file *of,
852 struct seq_file *seq, void *v)
853{
854 struct rdt_resource *r = of->kn->parent->priv;
855
856 seq_printf(seq, "%x\n", r->default_ctrl);
857 return 0;
858}
859
860static int rdt_min_cbm_bits_show(struct kernfs_open_file *of,
861 struct seq_file *seq, void *v)
862{
863 struct rdt_resource *r = of->kn->parent->priv;
864
865 seq_printf(seq, "%u\n", r->cache.min_cbm_bits);
866 return 0;
867}
868
869static int rdt_shareable_bits_show(struct kernfs_open_file *of,
870 struct seq_file *seq, void *v)
871{
872 struct rdt_resource *r = of->kn->parent->priv;
873
874 seq_printf(seq, "%x\n", r->cache.shareable_bits);
875 return 0;
876}
877
878/**
879 * rdt_bit_usage_show - Display current usage of resources
880 *
881 * A domain is a shared resource that can now be allocated differently. Here
882 * we display the current regions of the domain as an annotated bitmask.
883 * For each domain of this resource its allocation bitmask
884 * is annotated as below to indicate the current usage of the corresponding bit:
885 * 0 - currently unused
886 * X - currently available for sharing and used by software and hardware
887 * H - currently used by hardware only but available for software use
888 * S - currently used and shareable by software only
889 * E - currently used exclusively by one resource group
890 * P - currently pseudo-locked by one resource group
891 */
892static int rdt_bit_usage_show(struct kernfs_open_file *of,
893 struct seq_file *seq, void *v)
894{
895 struct rdt_resource *r = of->kn->parent->priv;
896 /*
897 * Use unsigned long even though only 32 bits are used to ensure
898 * test_bit() is used safely.
899 */
900 unsigned long sw_shareable = 0, hw_shareable = 0;
901 unsigned long exclusive = 0, pseudo_locked = 0;
902 struct rdt_domain *dom;
903 int i, hwb, swb, excl, psl;
904 enum rdtgrp_mode mode;
905 bool sep = false;
906 u32 *ctrl;
907
908 mutex_lock(&rdtgroup_mutex);
909 hw_shareable = r->cache.shareable_bits;
910 list_for_each_entry(dom, &r->domains, list) {
911 if (sep)
912 seq_putc(seq, ';');
913 ctrl = dom->ctrl_val;
914 sw_shareable = 0;
915 exclusive = 0;
916 seq_printf(seq, "%d=", dom->id);
917 for (i = 0; i < closids_supported(); i++, ctrl++) {
918 if (!closid_allocated(i))
919 continue;
920 mode = rdtgroup_mode_by_closid(i);
921 switch (mode) {
922 case RDT_MODE_SHAREABLE:
923 sw_shareable |= *ctrl;
924 break;
925 case RDT_MODE_EXCLUSIVE:
926 exclusive |= *ctrl;
927 break;
928 case RDT_MODE_PSEUDO_LOCKSETUP:
929 /*
930 * RDT_MODE_PSEUDO_LOCKSETUP is possible
931 * here but not included since the CBM
932 * associated with this CLOSID in this mode
933 * is not initialized and no task or cpu can be
934 * assigned this CLOSID.
935 */
936 break;
937 case RDT_MODE_PSEUDO_LOCKED:
938 case RDT_NUM_MODES:
939 WARN(1,
940 "invalid mode for closid %d\n", i);
941 break;
942 }
943 }
944 for (i = r->cache.cbm_len - 1; i >= 0; i--) {
945 pseudo_locked = dom->plr ? dom->plr->cbm : 0;
946 hwb = test_bit(i, &hw_shareable);
947 swb = test_bit(i, &sw_shareable);
948 excl = test_bit(i, &exclusive);
949 psl = test_bit(i, &pseudo_locked);
950 if (hwb && swb)
951 seq_putc(seq, 'X');
952 else if (hwb && !swb)
953 seq_putc(seq, 'H');
954 else if (!hwb && swb)
955 seq_putc(seq, 'S');
956 else if (excl)
957 seq_putc(seq, 'E');
958 else if (psl)
959 seq_putc(seq, 'P');
960 else /* Unused bits remain */
961 seq_putc(seq, '0');
962 }
963 sep = true;
964 }
965 seq_putc(seq, '\n');
966 mutex_unlock(&rdtgroup_mutex);
967 return 0;
968}
969
970static int rdt_min_bw_show(struct kernfs_open_file *of,
971 struct seq_file *seq, void *v)
972{
973 struct rdt_resource *r = of->kn->parent->priv;
974
975 seq_printf(seq, "%u\n", r->membw.min_bw);
976 return 0;
977}
978
979static int rdt_num_rmids_show(struct kernfs_open_file *of,
980 struct seq_file *seq, void *v)
981{
982 struct rdt_resource *r = of->kn->parent->priv;
983
984 seq_printf(seq, "%d\n", r->num_rmid);
985
986 return 0;
987}
988
989static int rdt_mon_features_show(struct kernfs_open_file *of,
990 struct seq_file *seq, void *v)
991{
992 struct rdt_resource *r = of->kn->parent->priv;
993 struct mon_evt *mevt;
994
995 list_for_each_entry(mevt, &r->evt_list, list)
996 seq_printf(seq, "%s\n", mevt->name);
997
998 return 0;
999}
1000
1001static int rdt_bw_gran_show(struct kernfs_open_file *of,
1002 struct seq_file *seq, void *v)
1003{
1004 struct rdt_resource *r = of->kn->parent->priv;
1005
1006 seq_printf(seq, "%u\n", r->membw.bw_gran);
1007 return 0;
1008}
1009
1010static int rdt_delay_linear_show(struct kernfs_open_file *of,
1011 struct seq_file *seq, void *v)
1012{
1013 struct rdt_resource *r = of->kn->parent->priv;
1014
1015 seq_printf(seq, "%u\n", r->membw.delay_linear);
1016 return 0;
1017}
1018
1019static int max_threshold_occ_show(struct kernfs_open_file *of,
1020 struct seq_file *seq, void *v)
1021{
1022 struct rdt_resource *r = of->kn->parent->priv;
1023
1024 seq_printf(seq, "%u\n", resctrl_cqm_threshold * r->mon_scale);
1025
1026 return 0;
1027}
1028
1029static int rdt_thread_throttle_mode_show(struct kernfs_open_file *of,
1030 struct seq_file *seq, void *v)
1031{
1032 struct rdt_resource *r = of->kn->parent->priv;
1033
1034 if (r->membw.throttle_mode == THREAD_THROTTLE_PER_THREAD)
1035 seq_puts(seq, "per-thread\n");
1036 else
1037 seq_puts(seq, "max\n");
1038
1039 return 0;
1040}
1041
1042static ssize_t max_threshold_occ_write(struct kernfs_open_file *of,
1043 char *buf, size_t nbytes, loff_t off)
1044{
1045 struct rdt_resource *r = of->kn->parent->priv;
1046 unsigned int bytes;
1047 int ret;
1048
1049 ret = kstrtouint(buf, 0, &bytes);
1050 if (ret)
1051 return ret;
1052
1053 if (bytes > (boot_cpu_data.x86_cache_size * 1024))
1054 return -EINVAL;
1055
1056 resctrl_cqm_threshold = bytes / r->mon_scale;
1057
1058 return nbytes;
1059}
1060
1061/*
1062 * rdtgroup_mode_show - Display mode of this resource group
1063 */
1064static int rdtgroup_mode_show(struct kernfs_open_file *of,
1065 struct seq_file *s, void *v)
1066{
1067 struct rdtgroup *rdtgrp;
1068
1069 rdtgrp = rdtgroup_kn_lock_live(of->kn);
1070 if (!rdtgrp) {
1071 rdtgroup_kn_unlock(of->kn);
1072 return -ENOENT;
1073 }
1074
1075 seq_printf(s, "%s\n", rdtgroup_mode_str(rdtgrp->mode));
1076
1077 rdtgroup_kn_unlock(of->kn);
1078 return 0;
1079}
1080
1081/**
1082 * rdt_cdp_peer_get - Retrieve CDP peer if it exists
1083 * @r: RDT resource to which RDT domain @d belongs
1084 * @d: Cache instance for which a CDP peer is requested
1085 * @r_cdp: RDT resource that shares hardware with @r (RDT resource peer)
1086 * Used to return the result.
1087 * @d_cdp: RDT domain that shares hardware with @d (RDT domain peer)
1088 * Used to return the result.
1089 *
1090 * RDT resources are managed independently and by extension the RDT domains
1091 * (RDT resource instances) are managed independently also. The Code and
1092 * Data Prioritization (CDP) RDT resources, while managed independently,
1093 * could refer to the same underlying hardware. For example,
1094 * RDT_RESOURCE_L2CODE and RDT_RESOURCE_L2DATA both refer to the L2 cache.
1095 *
1096 * When provided with an RDT resource @r and an instance of that RDT
1097 * resource @d rdt_cdp_peer_get() will return if there is a peer RDT
1098 * resource and the exact instance that shares the same hardware.
1099 *
1100 * Return: 0 if a CDP peer was found, <0 on error or if no CDP peer exists.
1101 * If a CDP peer was found, @r_cdp will point to the peer RDT resource
1102 * and @d_cdp will point to the peer RDT domain.
1103 */
1104static int rdt_cdp_peer_get(struct rdt_resource *r, struct rdt_domain *d,
1105 struct rdt_resource **r_cdp,
1106 struct rdt_domain **d_cdp)
1107{
1108 struct rdt_resource *_r_cdp = NULL;
1109 struct rdt_domain *_d_cdp = NULL;
1110 int ret = 0;
1111
1112 switch (r->rid) {
1113 case RDT_RESOURCE_L3DATA:
1114 _r_cdp = &rdt_resources_all[RDT_RESOURCE_L3CODE];
1115 break;
1116 case RDT_RESOURCE_L3CODE:
1117 _r_cdp = &rdt_resources_all[RDT_RESOURCE_L3DATA];
1118 break;
1119 case RDT_RESOURCE_L2DATA:
1120 _r_cdp = &rdt_resources_all[RDT_RESOURCE_L2CODE];
1121 break;
1122 case RDT_RESOURCE_L2CODE:
1123 _r_cdp = &rdt_resources_all[RDT_RESOURCE_L2DATA];
1124 break;
1125 default:
1126 ret = -ENOENT;
1127 goto out;
1128 }
1129
1130 /*
1131 * When a new CPU comes online and CDP is enabled then the new
1132 * RDT domains (if any) associated with both CDP RDT resources
1133 * are added in the same CPU online routine while the
1134 * rdtgroup_mutex is held. It should thus not happen for one
1135 * RDT domain to exist and be associated with its RDT CDP
1136 * resource but there is no RDT domain associated with the
1137 * peer RDT CDP resource. Hence the WARN.
1138 */
1139 _d_cdp = rdt_find_domain(_r_cdp, d->id, NULL);
1140 if (WARN_ON(IS_ERR_OR_NULL(_d_cdp))) {
1141 _r_cdp = NULL;
1142 _d_cdp = NULL;
1143 ret = -EINVAL;
1144 }
1145
1146out:
1147 *r_cdp = _r_cdp;
1148 *d_cdp = _d_cdp;
1149
1150 return ret;
1151}
1152
1153/**
1154 * __rdtgroup_cbm_overlaps - Does CBM for intended closid overlap with other
1155 * @r: Resource to which domain instance @d belongs.
1156 * @d: The domain instance for which @closid is being tested.
1157 * @cbm: Capacity bitmask being tested.
1158 * @closid: Intended closid for @cbm.
1159 * @exclusive: Only check if overlaps with exclusive resource groups
1160 *
1161 * Checks if provided @cbm intended to be used for @closid on domain
1162 * @d overlaps with any other closids or other hardware usage associated
1163 * with this domain. If @exclusive is true then only overlaps with
1164 * resource groups in exclusive mode will be considered. If @exclusive
1165 * is false then overlaps with any resource group or hardware entities
1166 * will be considered.
1167 *
1168 * @cbm is unsigned long, even if only 32 bits are used, to make the
1169 * bitmap functions work correctly.
1170 *
1171 * Return: false if CBM does not overlap, true if it does.
1172 */
1173static bool __rdtgroup_cbm_overlaps(struct rdt_resource *r, struct rdt_domain *d,
1174 unsigned long cbm, int closid, bool exclusive)
1175{
1176 enum rdtgrp_mode mode;
1177 unsigned long ctrl_b;
1178 u32 *ctrl;
1179 int i;
1180
1181 /* Check for any overlap with regions used by hardware directly */
1182 if (!exclusive) {
1183 ctrl_b = r->cache.shareable_bits;
1184 if (bitmap_intersects(&cbm, &ctrl_b, r->cache.cbm_len))
1185 return true;
1186 }
1187
1188 /* Check for overlap with other resource groups */
1189 ctrl = d->ctrl_val;
1190 for (i = 0; i < closids_supported(); i++, ctrl++) {
1191 ctrl_b = *ctrl;
1192 mode = rdtgroup_mode_by_closid(i);
1193 if (closid_allocated(i) && i != closid &&
1194 mode != RDT_MODE_PSEUDO_LOCKSETUP) {
1195 if (bitmap_intersects(&cbm, &ctrl_b, r->cache.cbm_len)) {
1196 if (exclusive) {
1197 if (mode == RDT_MODE_EXCLUSIVE)
1198 return true;
1199 continue;
1200 }
1201 return true;
1202 }
1203 }
1204 }
1205
1206 return false;
1207}
1208
1209/**
1210 * rdtgroup_cbm_overlaps - Does CBM overlap with other use of hardware
1211 * @r: Resource to which domain instance @d belongs.
1212 * @d: The domain instance for which @closid is being tested.
1213 * @cbm: Capacity bitmask being tested.
1214 * @closid: Intended closid for @cbm.
1215 * @exclusive: Only check if overlaps with exclusive resource groups
1216 *
1217 * Resources that can be allocated using a CBM can use the CBM to control
1218 * the overlap of these allocations. rdtgroup_cmb_overlaps() is the test
1219 * for overlap. Overlap test is not limited to the specific resource for
1220 * which the CBM is intended though - when dealing with CDP resources that
1221 * share the underlying hardware the overlap check should be performed on
1222 * the CDP resource sharing the hardware also.
1223 *
1224 * Refer to description of __rdtgroup_cbm_overlaps() for the details of the
1225 * overlap test.
1226 *
1227 * Return: true if CBM overlap detected, false if there is no overlap
1228 */
1229bool rdtgroup_cbm_overlaps(struct rdt_resource *r, struct rdt_domain *d,
1230 unsigned long cbm, int closid, bool exclusive)
1231{
1232 struct rdt_resource *r_cdp;
1233 struct rdt_domain *d_cdp;
1234
1235 if (__rdtgroup_cbm_overlaps(r, d, cbm, closid, exclusive))
1236 return true;
1237
1238 if (rdt_cdp_peer_get(r, d, &r_cdp, &d_cdp) < 0)
1239 return false;
1240
1241 return __rdtgroup_cbm_overlaps(r_cdp, d_cdp, cbm, closid, exclusive);
1242}
1243
1244/**
1245 * rdtgroup_mode_test_exclusive - Test if this resource group can be exclusive
1246 *
1247 * An exclusive resource group implies that there should be no sharing of
1248 * its allocated resources. At the time this group is considered to be
1249 * exclusive this test can determine if its current schemata supports this
1250 * setting by testing for overlap with all other resource groups.
1251 *
1252 * Return: true if resource group can be exclusive, false if there is overlap
1253 * with allocations of other resource groups and thus this resource group
1254 * cannot be exclusive.
1255 */
1256static bool rdtgroup_mode_test_exclusive(struct rdtgroup *rdtgrp)
1257{
1258 int closid = rdtgrp->closid;
1259 struct rdt_resource *r;
1260 bool has_cache = false;
1261 struct rdt_domain *d;
1262
1263 for_each_alloc_enabled_rdt_resource(r) {
1264 if (r->rid == RDT_RESOURCE_MBA)
1265 continue;
1266 has_cache = true;
1267 list_for_each_entry(d, &r->domains, list) {
1268 if (rdtgroup_cbm_overlaps(r, d, d->ctrl_val[closid],
1269 rdtgrp->closid, false)) {
1270 rdt_last_cmd_puts("Schemata overlaps\n");
1271 return false;
1272 }
1273 }
1274 }
1275
1276 if (!has_cache) {
1277 rdt_last_cmd_puts("Cannot be exclusive without CAT/CDP\n");
1278 return false;
1279 }
1280
1281 return true;
1282}
1283
1284/**
1285 * rdtgroup_mode_write - Modify the resource group's mode
1286 *
1287 */
1288static ssize_t rdtgroup_mode_write(struct kernfs_open_file *of,
1289 char *buf, size_t nbytes, loff_t off)
1290{
1291 struct rdtgroup *rdtgrp;
1292 enum rdtgrp_mode mode;
1293 int ret = 0;
1294
1295 /* Valid input requires a trailing newline */
1296 if (nbytes == 0 || buf[nbytes - 1] != '\n')
1297 return -EINVAL;
1298 buf[nbytes - 1] = '\0';
1299
1300 rdtgrp = rdtgroup_kn_lock_live(of->kn);
1301 if (!rdtgrp) {
1302 rdtgroup_kn_unlock(of->kn);
1303 return -ENOENT;
1304 }
1305
1306 rdt_last_cmd_clear();
1307
1308 mode = rdtgrp->mode;
1309
1310 if ((!strcmp(buf, "shareable") && mode == RDT_MODE_SHAREABLE) ||
1311 (!strcmp(buf, "exclusive") && mode == RDT_MODE_EXCLUSIVE) ||
1312 (!strcmp(buf, "pseudo-locksetup") &&
1313 mode == RDT_MODE_PSEUDO_LOCKSETUP) ||
1314 (!strcmp(buf, "pseudo-locked") && mode == RDT_MODE_PSEUDO_LOCKED))
1315 goto out;
1316
1317 if (mode == RDT_MODE_PSEUDO_LOCKED) {
1318 rdt_last_cmd_puts("Cannot change pseudo-locked group\n");
1319 ret = -EINVAL;
1320 goto out;
1321 }
1322
1323 if (!strcmp(buf, "shareable")) {
1324 if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
1325 ret = rdtgroup_locksetup_exit(rdtgrp);
1326 if (ret)
1327 goto out;
1328 }
1329 rdtgrp->mode = RDT_MODE_SHAREABLE;
1330 } else if (!strcmp(buf, "exclusive")) {
1331 if (!rdtgroup_mode_test_exclusive(rdtgrp)) {
1332 ret = -EINVAL;
1333 goto out;
1334 }
1335 if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
1336 ret = rdtgroup_locksetup_exit(rdtgrp);
1337 if (ret)
1338 goto out;
1339 }
1340 rdtgrp->mode = RDT_MODE_EXCLUSIVE;
1341 } else if (!strcmp(buf, "pseudo-locksetup")) {
1342 ret = rdtgroup_locksetup_enter(rdtgrp);
1343 if (ret)
1344 goto out;
1345 rdtgrp->mode = RDT_MODE_PSEUDO_LOCKSETUP;
1346 } else {
1347 rdt_last_cmd_puts("Unknown or unsupported mode\n");
1348 ret = -EINVAL;
1349 }
1350
1351out:
1352 rdtgroup_kn_unlock(of->kn);
1353 return ret ?: nbytes;
1354}
1355
1356/**
1357 * rdtgroup_cbm_to_size - Translate CBM to size in bytes
1358 * @r: RDT resource to which @d belongs.
1359 * @d: RDT domain instance.
1360 * @cbm: bitmask for which the size should be computed.
1361 *
1362 * The bitmask provided associated with the RDT domain instance @d will be
1363 * translated into how many bytes it represents. The size in bytes is
1364 * computed by first dividing the total cache size by the CBM length to
1365 * determine how many bytes each bit in the bitmask represents. The result
1366 * is multiplied with the number of bits set in the bitmask.
1367 *
1368 * @cbm is unsigned long, even if only 32 bits are used to make the
1369 * bitmap functions work correctly.
1370 */
1371unsigned int rdtgroup_cbm_to_size(struct rdt_resource *r,
1372 struct rdt_domain *d, unsigned long cbm)
1373{
1374 struct cpu_cacheinfo *ci;
1375 unsigned int size = 0;
1376 int num_b, i;
1377
1378 num_b = bitmap_weight(&cbm, r->cache.cbm_len);
1379 ci = get_cpu_cacheinfo(cpumask_any(&d->cpu_mask));
1380 for (i = 0; i < ci->num_leaves; i++) {
1381 if (ci->info_list[i].level == r->cache_level) {
1382 size = ci->info_list[i].size / r->cache.cbm_len * num_b;
1383 break;
1384 }
1385 }
1386
1387 return size;
1388}
1389
1390/**
1391 * rdtgroup_size_show - Display size in bytes of allocated regions
1392 *
1393 * The "size" file mirrors the layout of the "schemata" file, printing the
1394 * size in bytes of each region instead of the capacity bitmask.
1395 *
1396 */
1397static int rdtgroup_size_show(struct kernfs_open_file *of,
1398 struct seq_file *s, void *v)
1399{
1400 struct rdtgroup *rdtgrp;
1401 struct rdt_resource *r;
1402 struct rdt_domain *d;
1403 unsigned int size;
1404 int ret = 0;
1405 bool sep;
1406 u32 ctrl;
1407
1408 rdtgrp = rdtgroup_kn_lock_live(of->kn);
1409 if (!rdtgrp) {
1410 rdtgroup_kn_unlock(of->kn);
1411 return -ENOENT;
1412 }
1413
1414 if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
1415 if (!rdtgrp->plr->d) {
1416 rdt_last_cmd_clear();
1417 rdt_last_cmd_puts("Cache domain offline\n");
1418 ret = -ENODEV;
1419 } else {
1420 seq_printf(s, "%*s:", max_name_width,
1421 rdtgrp->plr->r->name);
1422 size = rdtgroup_cbm_to_size(rdtgrp->plr->r,
1423 rdtgrp->plr->d,
1424 rdtgrp->plr->cbm);
1425 seq_printf(s, "%d=%u\n", rdtgrp->plr->d->id, size);
1426 }
1427 goto out;
1428 }
1429
1430 for_each_alloc_enabled_rdt_resource(r) {
1431 sep = false;
1432 seq_printf(s, "%*s:", max_name_width, r->name);
1433 list_for_each_entry(d, &r->domains, list) {
1434 if (sep)
1435 seq_putc(s, ';');
1436 if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
1437 size = 0;
1438 } else {
1439 ctrl = (!is_mba_sc(r) ?
1440 d->ctrl_val[rdtgrp->closid] :
1441 d->mbps_val[rdtgrp->closid]);
1442 if (r->rid == RDT_RESOURCE_MBA)
1443 size = ctrl;
1444 else
1445 size = rdtgroup_cbm_to_size(r, d, ctrl);
1446 }
1447 seq_printf(s, "%d=%u", d->id, size);
1448 sep = true;
1449 }
1450 seq_putc(s, '\n');
1451 }
1452
1453out:
1454 rdtgroup_kn_unlock(of->kn);
1455
1456 return ret;
1457}
1458
1459/* rdtgroup information files for one cache resource. */
1460static struct rftype res_common_files[] = {
1461 {
1462 .name = "last_cmd_status",
1463 .mode = 0444,
1464 .kf_ops = &rdtgroup_kf_single_ops,
1465 .seq_show = rdt_last_cmd_status_show,
1466 .fflags = RF_TOP_INFO,
1467 },
1468 {
1469 .name = "num_closids",
1470 .mode = 0444,
1471 .kf_ops = &rdtgroup_kf_single_ops,
1472 .seq_show = rdt_num_closids_show,
1473 .fflags = RF_CTRL_INFO,
1474 },
1475 {
1476 .name = "mon_features",
1477 .mode = 0444,
1478 .kf_ops = &rdtgroup_kf_single_ops,
1479 .seq_show = rdt_mon_features_show,
1480 .fflags = RF_MON_INFO,
1481 },
1482 {
1483 .name = "num_rmids",
1484 .mode = 0444,
1485 .kf_ops = &rdtgroup_kf_single_ops,
1486 .seq_show = rdt_num_rmids_show,
1487 .fflags = RF_MON_INFO,
1488 },
1489 {
1490 .name = "cbm_mask",
1491 .mode = 0444,
1492 .kf_ops = &rdtgroup_kf_single_ops,
1493 .seq_show = rdt_default_ctrl_show,
1494 .fflags = RF_CTRL_INFO | RFTYPE_RES_CACHE,
1495 },
1496 {
1497 .name = "min_cbm_bits",
1498 .mode = 0444,
1499 .kf_ops = &rdtgroup_kf_single_ops,
1500 .seq_show = rdt_min_cbm_bits_show,
1501 .fflags = RF_CTRL_INFO | RFTYPE_RES_CACHE,
1502 },
1503 {
1504 .name = "shareable_bits",
1505 .mode = 0444,
1506 .kf_ops = &rdtgroup_kf_single_ops,
1507 .seq_show = rdt_shareable_bits_show,
1508 .fflags = RF_CTRL_INFO | RFTYPE_RES_CACHE,
1509 },
1510 {
1511 .name = "bit_usage",
1512 .mode = 0444,
1513 .kf_ops = &rdtgroup_kf_single_ops,
1514 .seq_show = rdt_bit_usage_show,
1515 .fflags = RF_CTRL_INFO | RFTYPE_RES_CACHE,
1516 },
1517 {
1518 .name = "min_bandwidth",
1519 .mode = 0444,
1520 .kf_ops = &rdtgroup_kf_single_ops,
1521 .seq_show = rdt_min_bw_show,
1522 .fflags = RF_CTRL_INFO | RFTYPE_RES_MB,
1523 },
1524 {
1525 .name = "bandwidth_gran",
1526 .mode = 0444,
1527 .kf_ops = &rdtgroup_kf_single_ops,
1528 .seq_show = rdt_bw_gran_show,
1529 .fflags = RF_CTRL_INFO | RFTYPE_RES_MB,
1530 },
1531 {
1532 .name = "delay_linear",
1533 .mode = 0444,
1534 .kf_ops = &rdtgroup_kf_single_ops,
1535 .seq_show = rdt_delay_linear_show,
1536 .fflags = RF_CTRL_INFO | RFTYPE_RES_MB,
1537 },
1538 /*
1539 * Platform specific which (if any) capabilities are provided by
1540 * thread_throttle_mode. Defer "fflags" initialization to platform
1541 * discovery.
1542 */
1543 {
1544 .name = "thread_throttle_mode",
1545 .mode = 0444,
1546 .kf_ops = &rdtgroup_kf_single_ops,
1547 .seq_show = rdt_thread_throttle_mode_show,
1548 },
1549 {
1550 .name = "max_threshold_occupancy",
1551 .mode = 0644,
1552 .kf_ops = &rdtgroup_kf_single_ops,
1553 .write = max_threshold_occ_write,
1554 .seq_show = max_threshold_occ_show,
1555 .fflags = RF_MON_INFO | RFTYPE_RES_CACHE,
1556 },
1557 {
1558 .name = "cpus",
1559 .mode = 0644,
1560 .kf_ops = &rdtgroup_kf_single_ops,
1561 .write = rdtgroup_cpus_write,
1562 .seq_show = rdtgroup_cpus_show,
1563 .fflags = RFTYPE_BASE,
1564 },
1565 {
1566 .name = "cpus_list",
1567 .mode = 0644,
1568 .kf_ops = &rdtgroup_kf_single_ops,
1569 .write = rdtgroup_cpus_write,
1570 .seq_show = rdtgroup_cpus_show,
1571 .flags = RFTYPE_FLAGS_CPUS_LIST,
1572 .fflags = RFTYPE_BASE,
1573 },
1574 {
1575 .name = "tasks",
1576 .mode = 0644,
1577 .kf_ops = &rdtgroup_kf_single_ops,
1578 .write = rdtgroup_tasks_write,
1579 .seq_show = rdtgroup_tasks_show,
1580 .fflags = RFTYPE_BASE,
1581 },
1582 {
1583 .name = "schemata",
1584 .mode = 0644,
1585 .kf_ops = &rdtgroup_kf_single_ops,
1586 .write = rdtgroup_schemata_write,
1587 .seq_show = rdtgroup_schemata_show,
1588 .fflags = RF_CTRL_BASE,
1589 },
1590 {
1591 .name = "mode",
1592 .mode = 0644,
1593 .kf_ops = &rdtgroup_kf_single_ops,
1594 .write = rdtgroup_mode_write,
1595 .seq_show = rdtgroup_mode_show,
1596 .fflags = RF_CTRL_BASE,
1597 },
1598 {
1599 .name = "size",
1600 .mode = 0444,
1601 .kf_ops = &rdtgroup_kf_single_ops,
1602 .seq_show = rdtgroup_size_show,
1603 .fflags = RF_CTRL_BASE,
1604 },
1605
1606};
1607
1608static int rdtgroup_add_files(struct kernfs_node *kn, unsigned long fflags)
1609{
1610 struct rftype *rfts, *rft;
1611 int ret, len;
1612
1613 rfts = res_common_files;
1614 len = ARRAY_SIZE(res_common_files);
1615
1616 lockdep_assert_held(&rdtgroup_mutex);
1617
1618 for (rft = rfts; rft < rfts + len; rft++) {
1619 if (rft->fflags && ((fflags & rft->fflags) == rft->fflags)) {
1620 ret = rdtgroup_add_file(kn, rft);
1621 if (ret)
1622 goto error;
1623 }
1624 }
1625
1626 return 0;
1627error:
1628 pr_warn("Failed to add %s, err=%d\n", rft->name, ret);
1629 while (--rft >= rfts) {
1630 if ((fflags & rft->fflags) == rft->fflags)
1631 kernfs_remove_by_name(kn, rft->name);
1632 }
1633 return ret;
1634}
1635
1636static struct rftype *rdtgroup_get_rftype_by_name(const char *name)
1637{
1638 struct rftype *rfts, *rft;
1639 int len;
1640
1641 rfts = res_common_files;
1642 len = ARRAY_SIZE(res_common_files);
1643
1644 for (rft = rfts; rft < rfts + len; rft++) {
1645 if (!strcmp(rft->name, name))
1646 return rft;
1647 }
1648
1649 return NULL;
1650}
1651
1652void __init thread_throttle_mode_init(void)
1653{
1654 struct rftype *rft;
1655
1656 rft = rdtgroup_get_rftype_by_name("thread_throttle_mode");
1657 if (!rft)
1658 return;
1659
1660 rft->fflags = RF_CTRL_INFO | RFTYPE_RES_MB;
1661}
1662
1663/**
1664 * rdtgroup_kn_mode_restrict - Restrict user access to named resctrl file
1665 * @r: The resource group with which the file is associated.
1666 * @name: Name of the file
1667 *
1668 * The permissions of named resctrl file, directory, or link are modified
1669 * to not allow read, write, or execute by any user.
1670 *
1671 * WARNING: This function is intended to communicate to the user that the
1672 * resctrl file has been locked down - that it is not relevant to the
1673 * particular state the system finds itself in. It should not be relied
1674 * on to protect from user access because after the file's permissions
1675 * are restricted the user can still change the permissions using chmod
1676 * from the command line.
1677 *
1678 * Return: 0 on success, <0 on failure.
1679 */
1680int rdtgroup_kn_mode_restrict(struct rdtgroup *r, const char *name)
1681{
1682 struct iattr iattr = {.ia_valid = ATTR_MODE,};
1683 struct kernfs_node *kn;
1684 int ret = 0;
1685
1686 kn = kernfs_find_and_get_ns(r->kn, name, NULL);
1687 if (!kn)
1688 return -ENOENT;
1689
1690 switch (kernfs_type(kn)) {
1691 case KERNFS_DIR:
1692 iattr.ia_mode = S_IFDIR;
1693 break;
1694 case KERNFS_FILE:
1695 iattr.ia_mode = S_IFREG;
1696 break;
1697 case KERNFS_LINK:
1698 iattr.ia_mode = S_IFLNK;
1699 break;
1700 }
1701
1702 ret = kernfs_setattr(kn, &iattr);
1703 kernfs_put(kn);
1704 return ret;
1705}
1706
1707/**
1708 * rdtgroup_kn_mode_restore - Restore user access to named resctrl file
1709 * @r: The resource group with which the file is associated.
1710 * @name: Name of the file
1711 * @mask: Mask of permissions that should be restored
1712 *
1713 * Restore the permissions of the named file. If @name is a directory the
1714 * permissions of its parent will be used.
1715 *
1716 * Return: 0 on success, <0 on failure.
1717 */
1718int rdtgroup_kn_mode_restore(struct rdtgroup *r, const char *name,
1719 umode_t mask)
1720{
1721 struct iattr iattr = {.ia_valid = ATTR_MODE,};
1722 struct kernfs_node *kn, *parent;
1723 struct rftype *rfts, *rft;
1724 int ret, len;
1725
1726 rfts = res_common_files;
1727 len = ARRAY_SIZE(res_common_files);
1728
1729 for (rft = rfts; rft < rfts + len; rft++) {
1730 if (!strcmp(rft->name, name))
1731 iattr.ia_mode = rft->mode & mask;
1732 }
1733
1734 kn = kernfs_find_and_get_ns(r->kn, name, NULL);
1735 if (!kn)
1736 return -ENOENT;
1737
1738 switch (kernfs_type(kn)) {
1739 case KERNFS_DIR:
1740 parent = kernfs_get_parent(kn);
1741 if (parent) {
1742 iattr.ia_mode |= parent->mode;
1743 kernfs_put(parent);
1744 }
1745 iattr.ia_mode |= S_IFDIR;
1746 break;
1747 case KERNFS_FILE:
1748 iattr.ia_mode |= S_IFREG;
1749 break;
1750 case KERNFS_LINK:
1751 iattr.ia_mode |= S_IFLNK;
1752 break;
1753 }
1754
1755 ret = kernfs_setattr(kn, &iattr);
1756 kernfs_put(kn);
1757 return ret;
1758}
1759
1760static int rdtgroup_mkdir_info_resdir(struct rdt_resource *r, char *name,
1761 unsigned long fflags)
1762{
1763 struct kernfs_node *kn_subdir;
1764 int ret;
1765
1766 kn_subdir = kernfs_create_dir(kn_info, name,
1767 kn_info->mode, r);
1768 if (IS_ERR(kn_subdir))
1769 return PTR_ERR(kn_subdir);
1770
1771 ret = rdtgroup_kn_set_ugid(kn_subdir);
1772 if (ret)
1773 return ret;
1774
1775 ret = rdtgroup_add_files(kn_subdir, fflags);
1776 if (!ret)
1777 kernfs_activate(kn_subdir);
1778
1779 return ret;
1780}
1781
1782static int rdtgroup_create_info_dir(struct kernfs_node *parent_kn)
1783{
1784 struct rdt_resource *r;
1785 unsigned long fflags;
1786 char name[32];
1787 int ret;
1788
1789 /* create the directory */
1790 kn_info = kernfs_create_dir(parent_kn, "info", parent_kn->mode, NULL);
1791 if (IS_ERR(kn_info))
1792 return PTR_ERR(kn_info);
1793
1794 ret = rdtgroup_add_files(kn_info, RF_TOP_INFO);
1795 if (ret)
1796 goto out_destroy;
1797
1798 for_each_alloc_enabled_rdt_resource(r) {
1799 fflags = r->fflags | RF_CTRL_INFO;
1800 ret = rdtgroup_mkdir_info_resdir(r, r->name, fflags);
1801 if (ret)
1802 goto out_destroy;
1803 }
1804
1805 for_each_mon_enabled_rdt_resource(r) {
1806 fflags = r->fflags | RF_MON_INFO;
1807 sprintf(name, "%s_MON", r->name);
1808 ret = rdtgroup_mkdir_info_resdir(r, name, fflags);
1809 if (ret)
1810 goto out_destroy;
1811 }
1812
1813 ret = rdtgroup_kn_set_ugid(kn_info);
1814 if (ret)
1815 goto out_destroy;
1816
1817 kernfs_activate(kn_info);
1818
1819 return 0;
1820
1821out_destroy:
1822 kernfs_remove(kn_info);
1823 return ret;
1824}
1825
1826static int
1827mongroup_create_dir(struct kernfs_node *parent_kn, struct rdtgroup *prgrp,
1828 char *name, struct kernfs_node **dest_kn)
1829{
1830 struct kernfs_node *kn;
1831 int ret;
1832
1833 /* create the directory */
1834 kn = kernfs_create_dir(parent_kn, name, parent_kn->mode, prgrp);
1835 if (IS_ERR(kn))
1836 return PTR_ERR(kn);
1837
1838 if (dest_kn)
1839 *dest_kn = kn;
1840
1841 ret = rdtgroup_kn_set_ugid(kn);
1842 if (ret)
1843 goto out_destroy;
1844
1845 kernfs_activate(kn);
1846
1847 return 0;
1848
1849out_destroy:
1850 kernfs_remove(kn);
1851 return ret;
1852}
1853
1854static void l3_qos_cfg_update(void *arg)
1855{
1856 bool *enable = arg;
1857
1858 wrmsrl(MSR_IA32_L3_QOS_CFG, *enable ? L3_QOS_CDP_ENABLE : 0ULL);
1859}
1860
1861static void l2_qos_cfg_update(void *arg)
1862{
1863 bool *enable = arg;
1864
1865 wrmsrl(MSR_IA32_L2_QOS_CFG, *enable ? L2_QOS_CDP_ENABLE : 0ULL);
1866}
1867
1868static inline bool is_mba_linear(void)
1869{
1870 return rdt_resources_all[RDT_RESOURCE_MBA].membw.delay_linear;
1871}
1872
1873static int set_cache_qos_cfg(int level, bool enable)
1874{
1875 void (*update)(void *arg);
1876 struct rdt_resource *r_l;
1877 cpumask_var_t cpu_mask;
1878 struct rdt_domain *d;
1879 int cpu;
1880
1881 if (level == RDT_RESOURCE_L3)
1882 update = l3_qos_cfg_update;
1883 else if (level == RDT_RESOURCE_L2)
1884 update = l2_qos_cfg_update;
1885 else
1886 return -EINVAL;
1887
1888 if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL))
1889 return -ENOMEM;
1890
1891 r_l = &rdt_resources_all[level];
1892 list_for_each_entry(d, &r_l->domains, list) {
1893 if (r_l->cache.arch_has_per_cpu_cfg)
1894 /* Pick all the CPUs in the domain instance */
1895 for_each_cpu(cpu, &d->cpu_mask)
1896 cpumask_set_cpu(cpu, cpu_mask);
1897 else
1898 /* Pick one CPU from each domain instance to update MSR */
1899 cpumask_set_cpu(cpumask_any(&d->cpu_mask), cpu_mask);
1900 }
1901 cpu = get_cpu();
1902 /* Update QOS_CFG MSR on this cpu if it's in cpu_mask. */
1903 if (cpumask_test_cpu(cpu, cpu_mask))
1904 update(&enable);
1905 /* Update QOS_CFG MSR on all other cpus in cpu_mask. */
1906 smp_call_function_many(cpu_mask, update, &enable, 1);
1907 put_cpu();
1908
1909 free_cpumask_var(cpu_mask);
1910
1911 return 0;
1912}
1913
1914/* Restore the qos cfg state when a domain comes online */
1915void rdt_domain_reconfigure_cdp(struct rdt_resource *r)
1916{
1917 if (!r->alloc_capable)
1918 return;
1919
1920 if (r == &rdt_resources_all[RDT_RESOURCE_L2DATA])
1921 l2_qos_cfg_update(&r->alloc_enabled);
1922
1923 if (r == &rdt_resources_all[RDT_RESOURCE_L3DATA])
1924 l3_qos_cfg_update(&r->alloc_enabled);
1925}
1926
1927/*
1928 * Enable or disable the MBA software controller
1929 * which helps user specify bandwidth in MBps.
1930 * MBA software controller is supported only if
1931 * MBM is supported and MBA is in linear scale.
1932 */
1933static int set_mba_sc(bool mba_sc)
1934{
1935 struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_MBA];
1936 struct rdt_domain *d;
1937
1938 if (!is_mbm_enabled() || !is_mba_linear() ||
1939 mba_sc == is_mba_sc(r))
1940 return -EINVAL;
1941
1942 r->membw.mba_sc = mba_sc;
1943 list_for_each_entry(d, &r->domains, list)
1944 setup_default_ctrlval(r, d->ctrl_val, d->mbps_val);
1945
1946 return 0;
1947}
1948
1949static int cdp_enable(int level, int data_type, int code_type)
1950{
1951 struct rdt_resource *r_ldata = &rdt_resources_all[data_type];
1952 struct rdt_resource *r_lcode = &rdt_resources_all[code_type];
1953 struct rdt_resource *r_l = &rdt_resources_all[level];
1954 int ret;
1955
1956 if (!r_l->alloc_capable || !r_ldata->alloc_capable ||
1957 !r_lcode->alloc_capable)
1958 return -EINVAL;
1959
1960 ret = set_cache_qos_cfg(level, true);
1961 if (!ret) {
1962 r_l->alloc_enabled = false;
1963 r_ldata->alloc_enabled = true;
1964 r_lcode->alloc_enabled = true;
1965 }
1966 return ret;
1967}
1968
1969static int cdpl3_enable(void)
1970{
1971 return cdp_enable(RDT_RESOURCE_L3, RDT_RESOURCE_L3DATA,
1972 RDT_RESOURCE_L3CODE);
1973}
1974
1975static int cdpl2_enable(void)
1976{
1977 return cdp_enable(RDT_RESOURCE_L2, RDT_RESOURCE_L2DATA,
1978 RDT_RESOURCE_L2CODE);
1979}
1980
1981static void cdp_disable(int level, int data_type, int code_type)
1982{
1983 struct rdt_resource *r = &rdt_resources_all[level];
1984
1985 r->alloc_enabled = r->alloc_capable;
1986
1987 if (rdt_resources_all[data_type].alloc_enabled) {
1988 rdt_resources_all[data_type].alloc_enabled = false;
1989 rdt_resources_all[code_type].alloc_enabled = false;
1990 set_cache_qos_cfg(level, false);
1991 }
1992}
1993
1994static void cdpl3_disable(void)
1995{
1996 cdp_disable(RDT_RESOURCE_L3, RDT_RESOURCE_L3DATA, RDT_RESOURCE_L3CODE);
1997}
1998
1999static void cdpl2_disable(void)
2000{
2001 cdp_disable(RDT_RESOURCE_L2, RDT_RESOURCE_L2DATA, RDT_RESOURCE_L2CODE);
2002}
2003
2004static void cdp_disable_all(void)
2005{
2006 if (rdt_resources_all[RDT_RESOURCE_L3DATA].alloc_enabled)
2007 cdpl3_disable();
2008 if (rdt_resources_all[RDT_RESOURCE_L2DATA].alloc_enabled)
2009 cdpl2_disable();
2010}
2011
2012/*
2013 * We don't allow rdtgroup directories to be created anywhere
2014 * except the root directory. Thus when looking for the rdtgroup
2015 * structure for a kernfs node we are either looking at a directory,
2016 * in which case the rdtgroup structure is pointed at by the "priv"
2017 * field, otherwise we have a file, and need only look to the parent
2018 * to find the rdtgroup.
2019 */
2020static struct rdtgroup *kernfs_to_rdtgroup(struct kernfs_node *kn)
2021{
2022 if (kernfs_type(kn) == KERNFS_DIR) {
2023 /*
2024 * All the resource directories use "kn->priv"
2025 * to point to the "struct rdtgroup" for the
2026 * resource. "info" and its subdirectories don't
2027 * have rdtgroup structures, so return NULL here.
2028 */
2029 if (kn == kn_info || kn->parent == kn_info)
2030 return NULL;
2031 else
2032 return kn->priv;
2033 } else {
2034 return kn->parent->priv;
2035 }
2036}
2037
2038struct rdtgroup *rdtgroup_kn_lock_live(struct kernfs_node *kn)
2039{
2040 struct rdtgroup *rdtgrp = kernfs_to_rdtgroup(kn);
2041
2042 if (!rdtgrp)
2043 return NULL;
2044
2045 atomic_inc(&rdtgrp->waitcount);
2046 kernfs_break_active_protection(kn);
2047
2048 mutex_lock(&rdtgroup_mutex);
2049
2050 /* Was this group deleted while we waited? */
2051 if (rdtgrp->flags & RDT_DELETED)
2052 return NULL;
2053
2054 return rdtgrp;
2055}
2056
2057void rdtgroup_kn_unlock(struct kernfs_node *kn)
2058{
2059 struct rdtgroup *rdtgrp = kernfs_to_rdtgroup(kn);
2060
2061 if (!rdtgrp)
2062 return;
2063
2064 mutex_unlock(&rdtgroup_mutex);
2065
2066 if (atomic_dec_and_test(&rdtgrp->waitcount) &&
2067 (rdtgrp->flags & RDT_DELETED)) {
2068 if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP ||
2069 rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED)
2070 rdtgroup_pseudo_lock_remove(rdtgrp);
2071 kernfs_unbreak_active_protection(kn);
2072 rdtgroup_remove(rdtgrp);
2073 } else {
2074 kernfs_unbreak_active_protection(kn);
2075 }
2076}
2077
2078static int mkdir_mondata_all(struct kernfs_node *parent_kn,
2079 struct rdtgroup *prgrp,
2080 struct kernfs_node **mon_data_kn);
2081
2082static int rdt_enable_ctx(struct rdt_fs_context *ctx)
2083{
2084 int ret = 0;
2085
2086 if (ctx->enable_cdpl2)
2087 ret = cdpl2_enable();
2088
2089 if (!ret && ctx->enable_cdpl3)
2090 ret = cdpl3_enable();
2091
2092 if (!ret && ctx->enable_mba_mbps)
2093 ret = set_mba_sc(true);
2094
2095 return ret;
2096}
2097
2098static int rdt_get_tree(struct fs_context *fc)
2099{
2100 struct rdt_fs_context *ctx = rdt_fc2context(fc);
2101 struct rdt_domain *dom;
2102 struct rdt_resource *r;
2103 int ret;
2104
2105 cpus_read_lock();
2106 mutex_lock(&rdtgroup_mutex);
2107 /*
2108 * resctrl file system can only be mounted once.
2109 */
2110 if (static_branch_unlikely(&rdt_enable_key)) {
2111 ret = -EBUSY;
2112 goto out;
2113 }
2114
2115 ret = rdt_enable_ctx(ctx);
2116 if (ret < 0)
2117 goto out_cdp;
2118
2119 closid_init();
2120
2121 ret = rdtgroup_create_info_dir(rdtgroup_default.kn);
2122 if (ret < 0)
2123 goto out_mba;
2124
2125 if (rdt_mon_capable) {
2126 ret = mongroup_create_dir(rdtgroup_default.kn,
2127 &rdtgroup_default, "mon_groups",
2128 &kn_mongrp);
2129 if (ret < 0)
2130 goto out_info;
2131
2132 ret = mkdir_mondata_all(rdtgroup_default.kn,
2133 &rdtgroup_default, &kn_mondata);
2134 if (ret < 0)
2135 goto out_mongrp;
2136 rdtgroup_default.mon.mon_data_kn = kn_mondata;
2137 }
2138
2139 ret = rdt_pseudo_lock_init();
2140 if (ret)
2141 goto out_mondata;
2142
2143 ret = kernfs_get_tree(fc);
2144 if (ret < 0)
2145 goto out_psl;
2146
2147 if (rdt_alloc_capable)
2148 static_branch_enable_cpuslocked(&rdt_alloc_enable_key);
2149 if (rdt_mon_capable)
2150 static_branch_enable_cpuslocked(&rdt_mon_enable_key);
2151
2152 if (rdt_alloc_capable || rdt_mon_capable)
2153 static_branch_enable_cpuslocked(&rdt_enable_key);
2154
2155 if (is_mbm_enabled()) {
2156 r = &rdt_resources_all[RDT_RESOURCE_L3];
2157 list_for_each_entry(dom, &r->domains, list)
2158 mbm_setup_overflow_handler(dom, MBM_OVERFLOW_INTERVAL);
2159 }
2160
2161 goto out;
2162
2163out_psl:
2164 rdt_pseudo_lock_release();
2165out_mondata:
2166 if (rdt_mon_capable)
2167 kernfs_remove(kn_mondata);
2168out_mongrp:
2169 if (rdt_mon_capable)
2170 kernfs_remove(kn_mongrp);
2171out_info:
2172 kernfs_remove(kn_info);
2173out_mba:
2174 if (ctx->enable_mba_mbps)
2175 set_mba_sc(false);
2176out_cdp:
2177 cdp_disable_all();
2178out:
2179 rdt_last_cmd_clear();
2180 mutex_unlock(&rdtgroup_mutex);
2181 cpus_read_unlock();
2182 return ret;
2183}
2184
2185enum rdt_param {
2186 Opt_cdp,
2187 Opt_cdpl2,
2188 Opt_mba_mbps,
2189 nr__rdt_params
2190};
2191
2192static const struct fs_parameter_spec rdt_fs_parameters[] = {
2193 fsparam_flag("cdp", Opt_cdp),
2194 fsparam_flag("cdpl2", Opt_cdpl2),
2195 fsparam_flag("mba_MBps", Opt_mba_mbps),
2196 {}
2197};
2198
2199static int rdt_parse_param(struct fs_context *fc, struct fs_parameter *param)
2200{
2201 struct rdt_fs_context *ctx = rdt_fc2context(fc);
2202 struct fs_parse_result result;
2203 int opt;
2204
2205 opt = fs_parse(fc, rdt_fs_parameters, param, &result);
2206 if (opt < 0)
2207 return opt;
2208
2209 switch (opt) {
2210 case Opt_cdp:
2211 ctx->enable_cdpl3 = true;
2212 return 0;
2213 case Opt_cdpl2:
2214 ctx->enable_cdpl2 = true;
2215 return 0;
2216 case Opt_mba_mbps:
2217 if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
2218 return -EINVAL;
2219 ctx->enable_mba_mbps = true;
2220 return 0;
2221 }
2222
2223 return -EINVAL;
2224}
2225
2226static void rdt_fs_context_free(struct fs_context *fc)
2227{
2228 struct rdt_fs_context *ctx = rdt_fc2context(fc);
2229
2230 kernfs_free_fs_context(fc);
2231 kfree(ctx);
2232}
2233
2234static const struct fs_context_operations rdt_fs_context_ops = {
2235 .free = rdt_fs_context_free,
2236 .parse_param = rdt_parse_param,
2237 .get_tree = rdt_get_tree,
2238};
2239
2240static int rdt_init_fs_context(struct fs_context *fc)
2241{
2242 struct rdt_fs_context *ctx;
2243
2244 ctx = kzalloc(sizeof(struct rdt_fs_context), GFP_KERNEL);
2245 if (!ctx)
2246 return -ENOMEM;
2247
2248 ctx->kfc.root = rdt_root;
2249 ctx->kfc.magic = RDTGROUP_SUPER_MAGIC;
2250 fc->fs_private = &ctx->kfc;
2251 fc->ops = &rdt_fs_context_ops;
2252 put_user_ns(fc->user_ns);
2253 fc->user_ns = get_user_ns(&init_user_ns);
2254 fc->global = true;
2255 return 0;
2256}
2257
2258static int reset_all_ctrls(struct rdt_resource *r)
2259{
2260 struct msr_param msr_param;
2261 cpumask_var_t cpu_mask;
2262 struct rdt_domain *d;
2263 int i, cpu;
2264
2265 if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL))
2266 return -ENOMEM;
2267
2268 msr_param.res = r;
2269 msr_param.low = 0;
2270 msr_param.high = r->num_closid;
2271
2272 /*
2273 * Disable resource control for this resource by setting all
2274 * CBMs in all domains to the maximum mask value. Pick one CPU
2275 * from each domain to update the MSRs below.
2276 */
2277 list_for_each_entry(d, &r->domains, list) {
2278 cpumask_set_cpu(cpumask_any(&d->cpu_mask), cpu_mask);
2279
2280 for (i = 0; i < r->num_closid; i++)
2281 d->ctrl_val[i] = r->default_ctrl;
2282 }
2283 cpu = get_cpu();
2284 /* Update CBM on this cpu if it's in cpu_mask. */
2285 if (cpumask_test_cpu(cpu, cpu_mask))
2286 rdt_ctrl_update(&msr_param);
2287 /* Update CBM on all other cpus in cpu_mask. */
2288 smp_call_function_many(cpu_mask, rdt_ctrl_update, &msr_param, 1);
2289 put_cpu();
2290
2291 free_cpumask_var(cpu_mask);
2292
2293 return 0;
2294}
2295
2296/*
2297 * Move tasks from one to the other group. If @from is NULL, then all tasks
2298 * in the systems are moved unconditionally (used for teardown).
2299 *
2300 * If @mask is not NULL the cpus on which moved tasks are running are set
2301 * in that mask so the update smp function call is restricted to affected
2302 * cpus.
2303 */
2304static void rdt_move_group_tasks(struct rdtgroup *from, struct rdtgroup *to,
2305 struct cpumask *mask)
2306{
2307 struct task_struct *p, *t;
2308
2309 read_lock(&tasklist_lock);
2310 for_each_process_thread(p, t) {
2311 if (!from || is_closid_match(t, from) ||
2312 is_rmid_match(t, from)) {
2313 WRITE_ONCE(t->closid, to->closid);
2314 WRITE_ONCE(t->rmid, to->mon.rmid);
2315
2316 /*
2317 * If the task is on a CPU, set the CPU in the mask.
2318 * The detection is inaccurate as tasks might move or
2319 * schedule before the smp function call takes place.
2320 * In such a case the function call is pointless, but
2321 * there is no other side effect.
2322 */
2323 if (IS_ENABLED(CONFIG_SMP) && mask && task_curr(t))
2324 cpumask_set_cpu(task_cpu(t), mask);
2325 }
2326 }
2327 read_unlock(&tasklist_lock);
2328}
2329
2330static void free_all_child_rdtgrp(struct rdtgroup *rdtgrp)
2331{
2332 struct rdtgroup *sentry, *stmp;
2333 struct list_head *head;
2334
2335 head = &rdtgrp->mon.crdtgrp_list;
2336 list_for_each_entry_safe(sentry, stmp, head, mon.crdtgrp_list) {
2337 free_rmid(sentry->mon.rmid);
2338 list_del(&sentry->mon.crdtgrp_list);
2339
2340 if (atomic_read(&sentry->waitcount) != 0)
2341 sentry->flags = RDT_DELETED;
2342 else
2343 rdtgroup_remove(sentry);
2344 }
2345}
2346
2347/*
2348 * Forcibly remove all of subdirectories under root.
2349 */
2350static void rmdir_all_sub(void)
2351{
2352 struct rdtgroup *rdtgrp, *tmp;
2353
2354 /* Move all tasks to the default resource group */
2355 rdt_move_group_tasks(NULL, &rdtgroup_default, NULL);
2356
2357 list_for_each_entry_safe(rdtgrp, tmp, &rdt_all_groups, rdtgroup_list) {
2358 /* Free any child rmids */
2359 free_all_child_rdtgrp(rdtgrp);
2360
2361 /* Remove each rdtgroup other than root */
2362 if (rdtgrp == &rdtgroup_default)
2363 continue;
2364
2365 if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP ||
2366 rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED)
2367 rdtgroup_pseudo_lock_remove(rdtgrp);
2368
2369 /*
2370 * Give any CPUs back to the default group. We cannot copy
2371 * cpu_online_mask because a CPU might have executed the
2372 * offline callback already, but is still marked online.
2373 */
2374 cpumask_or(&rdtgroup_default.cpu_mask,
2375 &rdtgroup_default.cpu_mask, &rdtgrp->cpu_mask);
2376
2377 free_rmid(rdtgrp->mon.rmid);
2378
2379 kernfs_remove(rdtgrp->kn);
2380 list_del(&rdtgrp->rdtgroup_list);
2381
2382 if (atomic_read(&rdtgrp->waitcount) != 0)
2383 rdtgrp->flags = RDT_DELETED;
2384 else
2385 rdtgroup_remove(rdtgrp);
2386 }
2387 /* Notify online CPUs to update per cpu storage and PQR_ASSOC MSR */
2388 update_closid_rmid(cpu_online_mask, &rdtgroup_default);
2389
2390 kernfs_remove(kn_info);
2391 kernfs_remove(kn_mongrp);
2392 kernfs_remove(kn_mondata);
2393}
2394
2395static void rdt_kill_sb(struct super_block *sb)
2396{
2397 struct rdt_resource *r;
2398
2399 cpus_read_lock();
2400 mutex_lock(&rdtgroup_mutex);
2401
2402 set_mba_sc(false);
2403
2404 /*Put everything back to default values. */
2405 for_each_alloc_enabled_rdt_resource(r)
2406 reset_all_ctrls(r);
2407 cdp_disable_all();
2408 rmdir_all_sub();
2409 rdt_pseudo_lock_release();
2410 rdtgroup_default.mode = RDT_MODE_SHAREABLE;
2411 static_branch_disable_cpuslocked(&rdt_alloc_enable_key);
2412 static_branch_disable_cpuslocked(&rdt_mon_enable_key);
2413 static_branch_disable_cpuslocked(&rdt_enable_key);
2414 kernfs_kill_sb(sb);
2415 mutex_unlock(&rdtgroup_mutex);
2416 cpus_read_unlock();
2417}
2418
2419static struct file_system_type rdt_fs_type = {
2420 .name = "resctrl",
2421 .init_fs_context = rdt_init_fs_context,
2422 .parameters = rdt_fs_parameters,
2423 .kill_sb = rdt_kill_sb,
2424};
2425
2426static int mon_addfile(struct kernfs_node *parent_kn, const char *name,
2427 void *priv)
2428{
2429 struct kernfs_node *kn;
2430 int ret = 0;
2431
2432 kn = __kernfs_create_file(parent_kn, name, 0444,
2433 GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, 0,
2434 &kf_mondata_ops, priv, NULL, NULL);
2435 if (IS_ERR(kn))
2436 return PTR_ERR(kn);
2437
2438 ret = rdtgroup_kn_set_ugid(kn);
2439 if (ret) {
2440 kernfs_remove(kn);
2441 return ret;
2442 }
2443
2444 return ret;
2445}
2446
2447/*
2448 * Remove all subdirectories of mon_data of ctrl_mon groups
2449 * and monitor groups with given domain id.
2450 */
2451void rmdir_mondata_subdir_allrdtgrp(struct rdt_resource *r, unsigned int dom_id)
2452{
2453 struct rdtgroup *prgrp, *crgrp;
2454 char name[32];
2455
2456 if (!r->mon_enabled)
2457 return;
2458
2459 list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) {
2460 sprintf(name, "mon_%s_%02d", r->name, dom_id);
2461 kernfs_remove_by_name(prgrp->mon.mon_data_kn, name);
2462
2463 list_for_each_entry(crgrp, &prgrp->mon.crdtgrp_list, mon.crdtgrp_list)
2464 kernfs_remove_by_name(crgrp->mon.mon_data_kn, name);
2465 }
2466}
2467
2468static int mkdir_mondata_subdir(struct kernfs_node *parent_kn,
2469 struct rdt_domain *d,
2470 struct rdt_resource *r, struct rdtgroup *prgrp)
2471{
2472 union mon_data_bits priv;
2473 struct kernfs_node *kn;
2474 struct mon_evt *mevt;
2475 struct rmid_read rr;
2476 char name[32];
2477 int ret;
2478
2479 sprintf(name, "mon_%s_%02d", r->name, d->id);
2480 /* create the directory */
2481 kn = kernfs_create_dir(parent_kn, name, parent_kn->mode, prgrp);
2482 if (IS_ERR(kn))
2483 return PTR_ERR(kn);
2484
2485 ret = rdtgroup_kn_set_ugid(kn);
2486 if (ret)
2487 goto out_destroy;
2488
2489 if (WARN_ON(list_empty(&r->evt_list))) {
2490 ret = -EPERM;
2491 goto out_destroy;
2492 }
2493
2494 priv.u.rid = r->rid;
2495 priv.u.domid = d->id;
2496 list_for_each_entry(mevt, &r->evt_list, list) {
2497 priv.u.evtid = mevt->evtid;
2498 ret = mon_addfile(kn, mevt->name, priv.priv);
2499 if (ret)
2500 goto out_destroy;
2501
2502 if (is_mbm_event(mevt->evtid))
2503 mon_event_read(&rr, r, d, prgrp, mevt->evtid, true);
2504 }
2505 kernfs_activate(kn);
2506 return 0;
2507
2508out_destroy:
2509 kernfs_remove(kn);
2510 return ret;
2511}
2512
2513/*
2514 * Add all subdirectories of mon_data for "ctrl_mon" groups
2515 * and "monitor" groups with given domain id.
2516 */
2517void mkdir_mondata_subdir_allrdtgrp(struct rdt_resource *r,
2518 struct rdt_domain *d)
2519{
2520 struct kernfs_node *parent_kn;
2521 struct rdtgroup *prgrp, *crgrp;
2522 struct list_head *head;
2523
2524 if (!r->mon_enabled)
2525 return;
2526
2527 list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) {
2528 parent_kn = prgrp->mon.mon_data_kn;
2529 mkdir_mondata_subdir(parent_kn, d, r, prgrp);
2530
2531 head = &prgrp->mon.crdtgrp_list;
2532 list_for_each_entry(crgrp, head, mon.crdtgrp_list) {
2533 parent_kn = crgrp->mon.mon_data_kn;
2534 mkdir_mondata_subdir(parent_kn, d, r, crgrp);
2535 }
2536 }
2537}
2538
2539static int mkdir_mondata_subdir_alldom(struct kernfs_node *parent_kn,
2540 struct rdt_resource *r,
2541 struct rdtgroup *prgrp)
2542{
2543 struct rdt_domain *dom;
2544 int ret;
2545
2546 list_for_each_entry(dom, &r->domains, list) {
2547 ret = mkdir_mondata_subdir(parent_kn, dom, r, prgrp);
2548 if (ret)
2549 return ret;
2550 }
2551
2552 return 0;
2553}
2554
2555/*
2556 * This creates a directory mon_data which contains the monitored data.
2557 *
2558 * mon_data has one directory for each domain which are named
2559 * in the format mon_<domain_name>_<domain_id>. For ex: A mon_data
2560 * with L3 domain looks as below:
2561 * ./mon_data:
2562 * mon_L3_00
2563 * mon_L3_01
2564 * mon_L3_02
2565 * ...
2566 *
2567 * Each domain directory has one file per event:
2568 * ./mon_L3_00/:
2569 * llc_occupancy
2570 *
2571 */
2572static int mkdir_mondata_all(struct kernfs_node *parent_kn,
2573 struct rdtgroup *prgrp,
2574 struct kernfs_node **dest_kn)
2575{
2576 struct rdt_resource *r;
2577 struct kernfs_node *kn;
2578 int ret;
2579
2580 /*
2581 * Create the mon_data directory first.
2582 */
2583 ret = mongroup_create_dir(parent_kn, prgrp, "mon_data", &kn);
2584 if (ret)
2585 return ret;
2586
2587 if (dest_kn)
2588 *dest_kn = kn;
2589
2590 /*
2591 * Create the subdirectories for each domain. Note that all events
2592 * in a domain like L3 are grouped into a resource whose domain is L3
2593 */
2594 for_each_mon_enabled_rdt_resource(r) {
2595 ret = mkdir_mondata_subdir_alldom(kn, r, prgrp);
2596 if (ret)
2597 goto out_destroy;
2598 }
2599
2600 return 0;
2601
2602out_destroy:
2603 kernfs_remove(kn);
2604 return ret;
2605}
2606
2607/**
2608 * cbm_ensure_valid - Enforce validity on provided CBM
2609 * @_val: Candidate CBM
2610 * @r: RDT resource to which the CBM belongs
2611 *
2612 * The provided CBM represents all cache portions available for use. This
2613 * may be represented by a bitmap that does not consist of contiguous ones
2614 * and thus be an invalid CBM.
2615 * Here the provided CBM is forced to be a valid CBM by only considering
2616 * the first set of contiguous bits as valid and clearing all bits.
2617 * The intention here is to provide a valid default CBM with which a new
2618 * resource group is initialized. The user can follow this with a
2619 * modification to the CBM if the default does not satisfy the
2620 * requirements.
2621 */
2622static u32 cbm_ensure_valid(u32 _val, struct rdt_resource *r)
2623{
2624 unsigned int cbm_len = r->cache.cbm_len;
2625 unsigned long first_bit, zero_bit;
2626 unsigned long val = _val;
2627
2628 if (!val)
2629 return 0;
2630
2631 first_bit = find_first_bit(&val, cbm_len);
2632 zero_bit = find_next_zero_bit(&val, cbm_len, first_bit);
2633
2634 /* Clear any remaining bits to ensure contiguous region */
2635 bitmap_clear(&val, zero_bit, cbm_len - zero_bit);
2636 return (u32)val;
2637}
2638
2639/*
2640 * Initialize cache resources per RDT domain
2641 *
2642 * Set the RDT domain up to start off with all usable allocations. That is,
2643 * all shareable and unused bits. All-zero CBM is invalid.
2644 */
2645static int __init_one_rdt_domain(struct rdt_domain *d, struct rdt_resource *r,
2646 u32 closid)
2647{
2648 struct rdt_resource *r_cdp = NULL;
2649 struct rdt_domain *d_cdp = NULL;
2650 u32 used_b = 0, unused_b = 0;
2651 unsigned long tmp_cbm;
2652 enum rdtgrp_mode mode;
2653 u32 peer_ctl, *ctrl;
2654 int i;
2655
2656 rdt_cdp_peer_get(r, d, &r_cdp, &d_cdp);
2657 d->have_new_ctrl = false;
2658 d->new_ctrl = r->cache.shareable_bits;
2659 used_b = r->cache.shareable_bits;
2660 ctrl = d->ctrl_val;
2661 for (i = 0; i < closids_supported(); i++, ctrl++) {
2662 if (closid_allocated(i) && i != closid) {
2663 mode = rdtgroup_mode_by_closid(i);
2664 if (mode == RDT_MODE_PSEUDO_LOCKSETUP)
2665 /*
2666 * ctrl values for locksetup aren't relevant
2667 * until the schemata is written, and the mode
2668 * becomes RDT_MODE_PSEUDO_LOCKED.
2669 */
2670 continue;
2671 /*
2672 * If CDP is active include peer domain's
2673 * usage to ensure there is no overlap
2674 * with an exclusive group.
2675 */
2676 if (d_cdp)
2677 peer_ctl = d_cdp->ctrl_val[i];
2678 else
2679 peer_ctl = 0;
2680 used_b |= *ctrl | peer_ctl;
2681 if (mode == RDT_MODE_SHAREABLE)
2682 d->new_ctrl |= *ctrl | peer_ctl;
2683 }
2684 }
2685 if (d->plr && d->plr->cbm > 0)
2686 used_b |= d->plr->cbm;
2687 unused_b = used_b ^ (BIT_MASK(r->cache.cbm_len) - 1);
2688 unused_b &= BIT_MASK(r->cache.cbm_len) - 1;
2689 d->new_ctrl |= unused_b;
2690 /*
2691 * Force the initial CBM to be valid, user can
2692 * modify the CBM based on system availability.
2693 */
2694 d->new_ctrl = cbm_ensure_valid(d->new_ctrl, r);
2695 /*
2696 * Assign the u32 CBM to an unsigned long to ensure that
2697 * bitmap_weight() does not access out-of-bound memory.
2698 */
2699 tmp_cbm = d->new_ctrl;
2700 if (bitmap_weight(&tmp_cbm, r->cache.cbm_len) < r->cache.min_cbm_bits) {
2701 rdt_last_cmd_printf("No space on %s:%d\n", r->name, d->id);
2702 return -ENOSPC;
2703 }
2704 d->have_new_ctrl = true;
2705
2706 return 0;
2707}
2708
2709/*
2710 * Initialize cache resources with default values.
2711 *
2712 * A new RDT group is being created on an allocation capable (CAT)
2713 * supporting system. Set this group up to start off with all usable
2714 * allocations.
2715 *
2716 * If there are no more shareable bits available on any domain then
2717 * the entire allocation will fail.
2718 */
2719static int rdtgroup_init_cat(struct rdt_resource *r, u32 closid)
2720{
2721 struct rdt_domain *d;
2722 int ret;
2723
2724 list_for_each_entry(d, &r->domains, list) {
2725 ret = __init_one_rdt_domain(d, r, closid);
2726 if (ret < 0)
2727 return ret;
2728 }
2729
2730 return 0;
2731}
2732
2733/* Initialize MBA resource with default values. */
2734static void rdtgroup_init_mba(struct rdt_resource *r)
2735{
2736 struct rdt_domain *d;
2737
2738 list_for_each_entry(d, &r->domains, list) {
2739 d->new_ctrl = is_mba_sc(r) ? MBA_MAX_MBPS : r->default_ctrl;
2740 d->have_new_ctrl = true;
2741 }
2742}
2743
2744/* Initialize the RDT group's allocations. */
2745static int rdtgroup_init_alloc(struct rdtgroup *rdtgrp)
2746{
2747 struct rdt_resource *r;
2748 int ret;
2749
2750 for_each_alloc_enabled_rdt_resource(r) {
2751 if (r->rid == RDT_RESOURCE_MBA) {
2752 rdtgroup_init_mba(r);
2753 } else {
2754 ret = rdtgroup_init_cat(r, rdtgrp->closid);
2755 if (ret < 0)
2756 return ret;
2757 }
2758
2759 ret = update_domains(r, rdtgrp->closid);
2760 if (ret < 0) {
2761 rdt_last_cmd_puts("Failed to initialize allocations\n");
2762 return ret;
2763 }
2764
2765 }
2766
2767 rdtgrp->mode = RDT_MODE_SHAREABLE;
2768
2769 return 0;
2770}
2771
2772static int mkdir_rdt_prepare(struct kernfs_node *parent_kn,
2773 const char *name, umode_t mode,
2774 enum rdt_group_type rtype, struct rdtgroup **r)
2775{
2776 struct rdtgroup *prdtgrp, *rdtgrp;
2777 struct kernfs_node *kn;
2778 uint files = 0;
2779 int ret;
2780
2781 prdtgrp = rdtgroup_kn_lock_live(parent_kn);
2782 if (!prdtgrp) {
2783 ret = -ENODEV;
2784 goto out_unlock;
2785 }
2786
2787 if (rtype == RDTMON_GROUP &&
2788 (prdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP ||
2789 prdtgrp->mode == RDT_MODE_PSEUDO_LOCKED)) {
2790 ret = -EINVAL;
2791 rdt_last_cmd_puts("Pseudo-locking in progress\n");
2792 goto out_unlock;
2793 }
2794
2795 /* allocate the rdtgroup. */
2796 rdtgrp = kzalloc(sizeof(*rdtgrp), GFP_KERNEL);
2797 if (!rdtgrp) {
2798 ret = -ENOSPC;
2799 rdt_last_cmd_puts("Kernel out of memory\n");
2800 goto out_unlock;
2801 }
2802 *r = rdtgrp;
2803 rdtgrp->mon.parent = prdtgrp;
2804 rdtgrp->type = rtype;
2805 INIT_LIST_HEAD(&rdtgrp->mon.crdtgrp_list);
2806
2807 /* kernfs creates the directory for rdtgrp */
2808 kn = kernfs_create_dir(parent_kn, name, mode, rdtgrp);
2809 if (IS_ERR(kn)) {
2810 ret = PTR_ERR(kn);
2811 rdt_last_cmd_puts("kernfs create error\n");
2812 goto out_free_rgrp;
2813 }
2814 rdtgrp->kn = kn;
2815
2816 /*
2817 * kernfs_remove() will drop the reference count on "kn" which
2818 * will free it. But we still need it to stick around for the
2819 * rdtgroup_kn_unlock(kn) call. Take one extra reference here,
2820 * which will be dropped by kernfs_put() in rdtgroup_remove().
2821 */
2822 kernfs_get(kn);
2823
2824 ret = rdtgroup_kn_set_ugid(kn);
2825 if (ret) {
2826 rdt_last_cmd_puts("kernfs perm error\n");
2827 goto out_destroy;
2828 }
2829
2830 files = RFTYPE_BASE | BIT(RF_CTRLSHIFT + rtype);
2831 ret = rdtgroup_add_files(kn, files);
2832 if (ret) {
2833 rdt_last_cmd_puts("kernfs fill error\n");
2834 goto out_destroy;
2835 }
2836
2837 if (rdt_mon_capable) {
2838 ret = alloc_rmid();
2839 if (ret < 0) {
2840 rdt_last_cmd_puts("Out of RMIDs\n");
2841 goto out_destroy;
2842 }
2843 rdtgrp->mon.rmid = ret;
2844
2845 ret = mkdir_mondata_all(kn, rdtgrp, &rdtgrp->mon.mon_data_kn);
2846 if (ret) {
2847 rdt_last_cmd_puts("kernfs subdir error\n");
2848 goto out_idfree;
2849 }
2850 }
2851 kernfs_activate(kn);
2852
2853 /*
2854 * The caller unlocks the parent_kn upon success.
2855 */
2856 return 0;
2857
2858out_idfree:
2859 free_rmid(rdtgrp->mon.rmid);
2860out_destroy:
2861 kernfs_put(rdtgrp->kn);
2862 kernfs_remove(rdtgrp->kn);
2863out_free_rgrp:
2864 kfree(rdtgrp);
2865out_unlock:
2866 rdtgroup_kn_unlock(parent_kn);
2867 return ret;
2868}
2869
2870static void mkdir_rdt_prepare_clean(struct rdtgroup *rgrp)
2871{
2872 kernfs_remove(rgrp->kn);
2873 free_rmid(rgrp->mon.rmid);
2874 rdtgroup_remove(rgrp);
2875}
2876
2877/*
2878 * Create a monitor group under "mon_groups" directory of a control
2879 * and monitor group(ctrl_mon). This is a resource group
2880 * to monitor a subset of tasks and cpus in its parent ctrl_mon group.
2881 */
2882static int rdtgroup_mkdir_mon(struct kernfs_node *parent_kn,
2883 const char *name, umode_t mode)
2884{
2885 struct rdtgroup *rdtgrp, *prgrp;
2886 int ret;
2887
2888 ret = mkdir_rdt_prepare(parent_kn, name, mode, RDTMON_GROUP, &rdtgrp);
2889 if (ret)
2890 return ret;
2891
2892 prgrp = rdtgrp->mon.parent;
2893 rdtgrp->closid = prgrp->closid;
2894
2895 /*
2896 * Add the rdtgrp to the list of rdtgrps the parent
2897 * ctrl_mon group has to track.
2898 */
2899 list_add_tail(&rdtgrp->mon.crdtgrp_list, &prgrp->mon.crdtgrp_list);
2900
2901 rdtgroup_kn_unlock(parent_kn);
2902 return ret;
2903}
2904
2905/*
2906 * These are rdtgroups created under the root directory. Can be used
2907 * to allocate and monitor resources.
2908 */
2909static int rdtgroup_mkdir_ctrl_mon(struct kernfs_node *parent_kn,
2910 const char *name, umode_t mode)
2911{
2912 struct rdtgroup *rdtgrp;
2913 struct kernfs_node *kn;
2914 u32 closid;
2915 int ret;
2916
2917 ret = mkdir_rdt_prepare(parent_kn, name, mode, RDTCTRL_GROUP, &rdtgrp);
2918 if (ret)
2919 return ret;
2920
2921 kn = rdtgrp->kn;
2922 ret = closid_alloc();
2923 if (ret < 0) {
2924 rdt_last_cmd_puts("Out of CLOSIDs\n");
2925 goto out_common_fail;
2926 }
2927 closid = ret;
2928 ret = 0;
2929
2930 rdtgrp->closid = closid;
2931 ret = rdtgroup_init_alloc(rdtgrp);
2932 if (ret < 0)
2933 goto out_id_free;
2934
2935 list_add(&rdtgrp->rdtgroup_list, &rdt_all_groups);
2936
2937 if (rdt_mon_capable) {
2938 /*
2939 * Create an empty mon_groups directory to hold the subset
2940 * of tasks and cpus to monitor.
2941 */
2942 ret = mongroup_create_dir(kn, rdtgrp, "mon_groups", NULL);
2943 if (ret) {
2944 rdt_last_cmd_puts("kernfs subdir error\n");
2945 goto out_del_list;
2946 }
2947 }
2948
2949 goto out_unlock;
2950
2951out_del_list:
2952 list_del(&rdtgrp->rdtgroup_list);
2953out_id_free:
2954 closid_free(closid);
2955out_common_fail:
2956 mkdir_rdt_prepare_clean(rdtgrp);
2957out_unlock:
2958 rdtgroup_kn_unlock(parent_kn);
2959 return ret;
2960}
2961
2962/*
2963 * We allow creating mon groups only with in a directory called "mon_groups"
2964 * which is present in every ctrl_mon group. Check if this is a valid
2965 * "mon_groups" directory.
2966 *
2967 * 1. The directory should be named "mon_groups".
2968 * 2. The mon group itself should "not" be named "mon_groups".
2969 * This makes sure "mon_groups" directory always has a ctrl_mon group
2970 * as parent.
2971 */
2972static bool is_mon_groups(struct kernfs_node *kn, const char *name)
2973{
2974 return (!strcmp(kn->name, "mon_groups") &&
2975 strcmp(name, "mon_groups"));
2976}
2977
2978static int rdtgroup_mkdir(struct kernfs_node *parent_kn, const char *name,
2979 umode_t mode)
2980{
2981 /* Do not accept '\n' to avoid unparsable situation. */
2982 if (strchr(name, '\n'))
2983 return -EINVAL;
2984
2985 /*
2986 * If the parent directory is the root directory and RDT
2987 * allocation is supported, add a control and monitoring
2988 * subdirectory
2989 */
2990 if (rdt_alloc_capable && parent_kn == rdtgroup_default.kn)
2991 return rdtgroup_mkdir_ctrl_mon(parent_kn, name, mode);
2992
2993 /*
2994 * If RDT monitoring is supported and the parent directory is a valid
2995 * "mon_groups" directory, add a monitoring subdirectory.
2996 */
2997 if (rdt_mon_capable && is_mon_groups(parent_kn, name))
2998 return rdtgroup_mkdir_mon(parent_kn, name, mode);
2999
3000 return -EPERM;
3001}
3002
3003static int rdtgroup_rmdir_mon(struct rdtgroup *rdtgrp, cpumask_var_t tmpmask)
3004{
3005 struct rdtgroup *prdtgrp = rdtgrp->mon.parent;
3006 int cpu;
3007
3008 /* Give any tasks back to the parent group */
3009 rdt_move_group_tasks(rdtgrp, prdtgrp, tmpmask);
3010
3011 /* Update per cpu rmid of the moved CPUs first */
3012 for_each_cpu(cpu, &rdtgrp->cpu_mask)
3013 per_cpu(pqr_state.default_rmid, cpu) = prdtgrp->mon.rmid;
3014 /*
3015 * Update the MSR on moved CPUs and CPUs which have moved
3016 * task running on them.
3017 */
3018 cpumask_or(tmpmask, tmpmask, &rdtgrp->cpu_mask);
3019 update_closid_rmid(tmpmask, NULL);
3020
3021 rdtgrp->flags = RDT_DELETED;
3022 free_rmid(rdtgrp->mon.rmid);
3023
3024 /*
3025 * Remove the rdtgrp from the parent ctrl_mon group's list
3026 */
3027 WARN_ON(list_empty(&prdtgrp->mon.crdtgrp_list));
3028 list_del(&rdtgrp->mon.crdtgrp_list);
3029
3030 kernfs_remove(rdtgrp->kn);
3031
3032 return 0;
3033}
3034
3035static int rdtgroup_ctrl_remove(struct rdtgroup *rdtgrp)
3036{
3037 rdtgrp->flags = RDT_DELETED;
3038 list_del(&rdtgrp->rdtgroup_list);
3039
3040 kernfs_remove(rdtgrp->kn);
3041 return 0;
3042}
3043
3044static int rdtgroup_rmdir_ctrl(struct rdtgroup *rdtgrp, cpumask_var_t tmpmask)
3045{
3046 int cpu;
3047
3048 /* Give any tasks back to the default group */
3049 rdt_move_group_tasks(rdtgrp, &rdtgroup_default, tmpmask);
3050
3051 /* Give any CPUs back to the default group */
3052 cpumask_or(&rdtgroup_default.cpu_mask,
3053 &rdtgroup_default.cpu_mask, &rdtgrp->cpu_mask);
3054
3055 /* Update per cpu closid and rmid of the moved CPUs first */
3056 for_each_cpu(cpu, &rdtgrp->cpu_mask) {
3057 per_cpu(pqr_state.default_closid, cpu) = rdtgroup_default.closid;
3058 per_cpu(pqr_state.default_rmid, cpu) = rdtgroup_default.mon.rmid;
3059 }
3060
3061 /*
3062 * Update the MSR on moved CPUs and CPUs which have moved
3063 * task running on them.
3064 */
3065 cpumask_or(tmpmask, tmpmask, &rdtgrp->cpu_mask);
3066 update_closid_rmid(tmpmask, NULL);
3067
3068 closid_free(rdtgrp->closid);
3069 free_rmid(rdtgrp->mon.rmid);
3070
3071 rdtgroup_ctrl_remove(rdtgrp);
3072
3073 /*
3074 * Free all the child monitor group rmids.
3075 */
3076 free_all_child_rdtgrp(rdtgrp);
3077
3078 return 0;
3079}
3080
3081static int rdtgroup_rmdir(struct kernfs_node *kn)
3082{
3083 struct kernfs_node *parent_kn = kn->parent;
3084 struct rdtgroup *rdtgrp;
3085 cpumask_var_t tmpmask;
3086 int ret = 0;
3087
3088 if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL))
3089 return -ENOMEM;
3090
3091 rdtgrp = rdtgroup_kn_lock_live(kn);
3092 if (!rdtgrp) {
3093 ret = -EPERM;
3094 goto out;
3095 }
3096
3097 /*
3098 * If the rdtgroup is a ctrl_mon group and parent directory
3099 * is the root directory, remove the ctrl_mon group.
3100 *
3101 * If the rdtgroup is a mon group and parent directory
3102 * is a valid "mon_groups" directory, remove the mon group.
3103 */
3104 if (rdtgrp->type == RDTCTRL_GROUP && parent_kn == rdtgroup_default.kn &&
3105 rdtgrp != &rdtgroup_default) {
3106 if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP ||
3107 rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
3108 ret = rdtgroup_ctrl_remove(rdtgrp);
3109 } else {
3110 ret = rdtgroup_rmdir_ctrl(rdtgrp, tmpmask);
3111 }
3112 } else if (rdtgrp->type == RDTMON_GROUP &&
3113 is_mon_groups(parent_kn, kn->name)) {
3114 ret = rdtgroup_rmdir_mon(rdtgrp, tmpmask);
3115 } else {
3116 ret = -EPERM;
3117 }
3118
3119out:
3120 rdtgroup_kn_unlock(kn);
3121 free_cpumask_var(tmpmask);
3122 return ret;
3123}
3124
3125static int rdtgroup_show_options(struct seq_file *seq, struct kernfs_root *kf)
3126{
3127 if (rdt_resources_all[RDT_RESOURCE_L3DATA].alloc_enabled)
3128 seq_puts(seq, ",cdp");
3129
3130 if (rdt_resources_all[RDT_RESOURCE_L2DATA].alloc_enabled)
3131 seq_puts(seq, ",cdpl2");
3132
3133 if (is_mba_sc(&rdt_resources_all[RDT_RESOURCE_MBA]))
3134 seq_puts(seq, ",mba_MBps");
3135
3136 return 0;
3137}
3138
3139static struct kernfs_syscall_ops rdtgroup_kf_syscall_ops = {
3140 .mkdir = rdtgroup_mkdir,
3141 .rmdir = rdtgroup_rmdir,
3142 .show_options = rdtgroup_show_options,
3143};
3144
3145static int __init rdtgroup_setup_root(void)
3146{
3147 int ret;
3148
3149 rdt_root = kernfs_create_root(&rdtgroup_kf_syscall_ops,
3150 KERNFS_ROOT_CREATE_DEACTIVATED |
3151 KERNFS_ROOT_EXTRA_OPEN_PERM_CHECK,
3152 &rdtgroup_default);
3153 if (IS_ERR(rdt_root))
3154 return PTR_ERR(rdt_root);
3155
3156 mutex_lock(&rdtgroup_mutex);
3157
3158 rdtgroup_default.closid = 0;
3159 rdtgroup_default.mon.rmid = 0;
3160 rdtgroup_default.type = RDTCTRL_GROUP;
3161 INIT_LIST_HEAD(&rdtgroup_default.mon.crdtgrp_list);
3162
3163 list_add(&rdtgroup_default.rdtgroup_list, &rdt_all_groups);
3164
3165 ret = rdtgroup_add_files(rdt_root->kn, RF_CTRL_BASE);
3166 if (ret) {
3167 kernfs_destroy_root(rdt_root);
3168 goto out;
3169 }
3170
3171 rdtgroup_default.kn = rdt_root->kn;
3172 kernfs_activate(rdtgroup_default.kn);
3173
3174out:
3175 mutex_unlock(&rdtgroup_mutex);
3176
3177 return ret;
3178}
3179
3180/*
3181 * rdtgroup_init - rdtgroup initialization
3182 *
3183 * Setup resctrl file system including set up root, create mount point,
3184 * register rdtgroup filesystem, and initialize files under root directory.
3185 *
3186 * Return: 0 on success or -errno
3187 */
3188int __init rdtgroup_init(void)
3189{
3190 int ret = 0;
3191
3192 seq_buf_init(&last_cmd_status, last_cmd_status_buf,
3193 sizeof(last_cmd_status_buf));
3194
3195 ret = rdtgroup_setup_root();
3196 if (ret)
3197 return ret;
3198
3199 ret = sysfs_create_mount_point(fs_kobj, "resctrl");
3200 if (ret)
3201 goto cleanup_root;
3202
3203 ret = register_filesystem(&rdt_fs_type);
3204 if (ret)
3205 goto cleanup_mountpoint;
3206
3207 /*
3208 * Adding the resctrl debugfs directory here may not be ideal since
3209 * it would let the resctrl debugfs directory appear on the debugfs
3210 * filesystem before the resctrl filesystem is mounted.
3211 * It may also be ok since that would enable debugging of RDT before
3212 * resctrl is mounted.
3213 * The reason why the debugfs directory is created here and not in
3214 * rdt_get_tree() is because rdt_get_tree() takes rdtgroup_mutex and
3215 * during the debugfs directory creation also &sb->s_type->i_mutex_key
3216 * (the lockdep class of inode->i_rwsem). Other filesystem
3217 * interactions (eg. SyS_getdents) have the lock ordering:
3218 * &sb->s_type->i_mutex_key --> &mm->mmap_lock
3219 * During mmap(), called with &mm->mmap_lock, the rdtgroup_mutex
3220 * is taken, thus creating dependency:
3221 * &mm->mmap_lock --> rdtgroup_mutex for the latter that can cause
3222 * issues considering the other two lock dependencies.
3223 * By creating the debugfs directory here we avoid a dependency
3224 * that may cause deadlock (even though file operations cannot
3225 * occur until the filesystem is mounted, but I do not know how to
3226 * tell lockdep that).
3227 */
3228 debugfs_resctrl = debugfs_create_dir("resctrl", NULL);
3229
3230 return 0;
3231
3232cleanup_mountpoint:
3233 sysfs_remove_mount_point(fs_kobj, "resctrl");
3234cleanup_root:
3235 kernfs_destroy_root(rdt_root);
3236
3237 return ret;
3238}
3239
3240void __exit rdtgroup_exit(void)
3241{
3242 debugfs_remove_recursive(debugfs_resctrl);
3243 unregister_filesystem(&rdt_fs_type);
3244 sysfs_remove_mount_point(fs_kobj, "resctrl");
3245 kernfs_destroy_root(rdt_root);
3246}