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5ff193fb FY |
1 | /* |
2 | * User interface for Resource Alloction in Resource Director Technology(RDT) | |
3 | * | |
4 | * Copyright (C) 2016 Intel Corporation | |
5 | * | |
6 | * Author: Fenghua Yu <fenghua.yu@intel.com> | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify it | |
9 | * under the terms and conditions of the GNU General Public License, | |
10 | * version 2, as published by the Free Software Foundation. | |
11 | * | |
12 | * This program is distributed in the hope it will be useful, but WITHOUT | |
13 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
14 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
15 | * more details. | |
16 | * | |
17 | * More information about RDT be found in the Intel (R) x86 Architecture | |
18 | * Software Developer Manual. | |
19 | */ | |
20 | ||
21 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
22 | ||
12e0110c | 23 | #include <linux/cpu.h> |
5ff193fb FY |
24 | #include <linux/fs.h> |
25 | #include <linux/sysfs.h> | |
26 | #include <linux/kernfs.h> | |
4e978d06 | 27 | #include <linux/seq_file.h> |
3f07c014 | 28 | #include <linux/sched/signal.h> |
29930025 | 29 | #include <linux/sched/task.h> |
5ff193fb | 30 | #include <linux/slab.h> |
e02737d5 | 31 | #include <linux/task_work.h> |
5ff193fb FY |
32 | |
33 | #include <uapi/linux/magic.h> | |
34 | ||
35 | #include <asm/intel_rdt.h> | |
60cf5e10 | 36 | #include <asm/intel_rdt_common.h> |
5ff193fb FY |
37 | |
38 | DEFINE_STATIC_KEY_FALSE(rdt_enable_key); | |
39 | struct kernfs_root *rdt_root; | |
40 | struct rdtgroup rdtgroup_default; | |
41 | LIST_HEAD(rdt_all_groups); | |
42 | ||
4e978d06 FY |
43 | /* Kernel fs node for "info" directory under root */ |
44 | static struct kernfs_node *kn_info; | |
45 | ||
60cf5e10 FY |
46 | /* |
47 | * Trivial allocator for CLOSIDs. Since h/w only supports a small number, | |
48 | * we can keep a bitmap of free CLOSIDs in a single integer. | |
49 | * | |
50 | * Using a global CLOSID across all resources has some advantages and | |
51 | * some drawbacks: | |
52 | * + We can simply set "current->closid" to assign a task to a resource | |
53 | * group. | |
54 | * + Context switch code can avoid extra memory references deciding which | |
55 | * CLOSID to load into the PQR_ASSOC MSR | |
56 | * - We give up some options in configuring resource groups across multi-socket | |
57 | * systems. | |
58 | * - Our choices on how to configure each resource become progressively more | |
59 | * limited as the number of resources grows. | |
60 | */ | |
61 | static int closid_free_map; | |
62 | ||
63 | static void closid_init(void) | |
64 | { | |
65 | struct rdt_resource *r; | |
66 | int rdt_min_closid = 32; | |
67 | ||
68 | /* Compute rdt_min_closid across all resources */ | |
69 | for_each_enabled_rdt_resource(r) | |
70 | rdt_min_closid = min(rdt_min_closid, r->num_closid); | |
71 | ||
72 | closid_free_map = BIT_MASK(rdt_min_closid) - 1; | |
73 | ||
74 | /* CLOSID 0 is always reserved for the default group */ | |
75 | closid_free_map &= ~1; | |
76 | } | |
77 | ||
78 | int closid_alloc(void) | |
79 | { | |
80 | int closid = ffs(closid_free_map); | |
81 | ||
82 | if (closid == 0) | |
83 | return -ENOSPC; | |
84 | closid--; | |
85 | closid_free_map &= ~(1 << closid); | |
86 | ||
87 | return closid; | |
88 | } | |
89 | ||
90 | static void closid_free(int closid) | |
91 | { | |
92 | closid_free_map |= 1 << closid; | |
93 | } | |
94 | ||
4e978d06 FY |
95 | /* set uid and gid of rdtgroup dirs and files to that of the creator */ |
96 | static int rdtgroup_kn_set_ugid(struct kernfs_node *kn) | |
97 | { | |
98 | struct iattr iattr = { .ia_valid = ATTR_UID | ATTR_GID, | |
99 | .ia_uid = current_fsuid(), | |
100 | .ia_gid = current_fsgid(), }; | |
101 | ||
102 | if (uid_eq(iattr.ia_uid, GLOBAL_ROOT_UID) && | |
103 | gid_eq(iattr.ia_gid, GLOBAL_ROOT_GID)) | |
104 | return 0; | |
105 | ||
106 | return kernfs_setattr(kn, &iattr); | |
107 | } | |
108 | ||
109 | static int rdtgroup_add_file(struct kernfs_node *parent_kn, struct rftype *rft) | |
110 | { | |
111 | struct kernfs_node *kn; | |
112 | int ret; | |
113 | ||
114 | kn = __kernfs_create_file(parent_kn, rft->name, rft->mode, | |
115 | 0, rft->kf_ops, rft, NULL, NULL); | |
116 | if (IS_ERR(kn)) | |
117 | return PTR_ERR(kn); | |
118 | ||
119 | ret = rdtgroup_kn_set_ugid(kn); | |
120 | if (ret) { | |
121 | kernfs_remove(kn); | |
122 | return ret; | |
123 | } | |
124 | ||
125 | return 0; | |
126 | } | |
127 | ||
128 | static int rdtgroup_add_files(struct kernfs_node *kn, struct rftype *rfts, | |
129 | int len) | |
130 | { | |
131 | struct rftype *rft; | |
132 | int ret; | |
133 | ||
134 | lockdep_assert_held(&rdtgroup_mutex); | |
135 | ||
136 | for (rft = rfts; rft < rfts + len; rft++) { | |
137 | ret = rdtgroup_add_file(kn, rft); | |
138 | if (ret) | |
139 | goto error; | |
140 | } | |
141 | ||
142 | return 0; | |
143 | error: | |
144 | pr_warn("Failed to add %s, err=%d\n", rft->name, ret); | |
145 | while (--rft >= rfts) | |
146 | kernfs_remove_by_name(kn, rft->name); | |
147 | return ret; | |
148 | } | |
149 | ||
150 | static int rdtgroup_seqfile_show(struct seq_file *m, void *arg) | |
151 | { | |
152 | struct kernfs_open_file *of = m->private; | |
153 | struct rftype *rft = of->kn->priv; | |
154 | ||
155 | if (rft->seq_show) | |
156 | return rft->seq_show(of, m, arg); | |
157 | return 0; | |
158 | } | |
159 | ||
160 | static ssize_t rdtgroup_file_write(struct kernfs_open_file *of, char *buf, | |
161 | size_t nbytes, loff_t off) | |
162 | { | |
163 | struct rftype *rft = of->kn->priv; | |
164 | ||
165 | if (rft->write) | |
166 | return rft->write(of, buf, nbytes, off); | |
167 | ||
168 | return -EINVAL; | |
169 | } | |
170 | ||
171 | static struct kernfs_ops rdtgroup_kf_single_ops = { | |
172 | .atomic_write_len = PAGE_SIZE, | |
173 | .write = rdtgroup_file_write, | |
174 | .seq_show = rdtgroup_seqfile_show, | |
175 | }; | |
176 | ||
4ffa3c97 JO |
177 | static bool is_cpu_list(struct kernfs_open_file *of) |
178 | { | |
179 | struct rftype *rft = of->kn->priv; | |
180 | ||
181 | return rft->flags & RFTYPE_FLAGS_CPUS_LIST; | |
182 | } | |
183 | ||
12e0110c TL |
184 | static int rdtgroup_cpus_show(struct kernfs_open_file *of, |
185 | struct seq_file *s, void *v) | |
186 | { | |
187 | struct rdtgroup *rdtgrp; | |
188 | int ret = 0; | |
189 | ||
190 | rdtgrp = rdtgroup_kn_lock_live(of->kn); | |
191 | ||
4ffa3c97 JO |
192 | if (rdtgrp) { |
193 | seq_printf(s, is_cpu_list(of) ? "%*pbl\n" : "%*pb\n", | |
194 | cpumask_pr_args(&rdtgrp->cpu_mask)); | |
195 | } else { | |
12e0110c | 196 | ret = -ENOENT; |
4ffa3c97 | 197 | } |
12e0110c TL |
198 | rdtgroup_kn_unlock(of->kn); |
199 | ||
200 | return ret; | |
201 | } | |
202 | ||
f4107702 FY |
203 | /* |
204 | * This is safe against intel_rdt_sched_in() called from __switch_to() | |
205 | * because __switch_to() is executed with interrupts disabled. A local call | |
0efc89be | 206 | * from rdt_update_closid() is proteced against __switch_to() because |
f4107702 FY |
207 | * preemption is disabled. |
208 | */ | |
0efc89be | 209 | static void rdt_update_cpu_closid(void *closid) |
f4107702 | 210 | { |
0efc89be FY |
211 | if (closid) |
212 | this_cpu_write(cpu_closid, *(int *)closid); | |
f4107702 FY |
213 | /* |
214 | * We cannot unconditionally write the MSR because the current | |
215 | * executing task might have its own closid selected. Just reuse | |
216 | * the context switch code. | |
217 | */ | |
218 | intel_rdt_sched_in(); | |
219 | } | |
220 | ||
0efc89be FY |
221 | /* |
222 | * Update the PGR_ASSOC MSR on all cpus in @cpu_mask, | |
223 | * | |
224 | * Per task closids must have been set up before calling this function. | |
225 | * | |
226 | * The per cpu closids are updated with the smp function call, when @closid | |
227 | * is not NULL. If @closid is NULL then all affected percpu closids must | |
228 | * have been set up before calling this function. | |
229 | */ | |
230 | static void | |
231 | rdt_update_closid(const struct cpumask *cpu_mask, int *closid) | |
f4107702 FY |
232 | { |
233 | int cpu = get_cpu(); | |
234 | ||
235 | if (cpumask_test_cpu(cpu, cpu_mask)) | |
0efc89be FY |
236 | rdt_update_cpu_closid(closid); |
237 | smp_call_function_many(cpu_mask, rdt_update_cpu_closid, closid, 1); | |
f4107702 FY |
238 | put_cpu(); |
239 | } | |
240 | ||
12e0110c TL |
241 | static ssize_t rdtgroup_cpus_write(struct kernfs_open_file *of, |
242 | char *buf, size_t nbytes, loff_t off) | |
243 | { | |
244 | cpumask_var_t tmpmask, newmask; | |
245 | struct rdtgroup *rdtgrp, *r; | |
f4107702 | 246 | int ret; |
12e0110c TL |
247 | |
248 | if (!buf) | |
249 | return -EINVAL; | |
250 | ||
251 | if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL)) | |
252 | return -ENOMEM; | |
253 | if (!zalloc_cpumask_var(&newmask, GFP_KERNEL)) { | |
254 | free_cpumask_var(tmpmask); | |
255 | return -ENOMEM; | |
256 | } | |
a2584e1d | 257 | |
12e0110c TL |
258 | rdtgrp = rdtgroup_kn_lock_live(of->kn); |
259 | if (!rdtgrp) { | |
260 | ret = -ENOENT; | |
261 | goto unlock; | |
262 | } | |
263 | ||
4ffa3c97 JO |
264 | if (is_cpu_list(of)) |
265 | ret = cpulist_parse(buf, newmask); | |
266 | else | |
267 | ret = cpumask_parse(buf, newmask); | |
268 | ||
12e0110c TL |
269 | if (ret) |
270 | goto unlock; | |
271 | ||
12e0110c TL |
272 | /* check that user didn't specify any offline cpus */ |
273 | cpumask_andnot(tmpmask, newmask, cpu_online_mask); | |
274 | if (cpumask_weight(tmpmask)) { | |
275 | ret = -EINVAL; | |
a2584e1d | 276 | goto unlock; |
12e0110c TL |
277 | } |
278 | ||
279 | /* Check whether cpus are dropped from this group */ | |
280 | cpumask_andnot(tmpmask, &rdtgrp->cpu_mask, newmask); | |
281 | if (cpumask_weight(tmpmask)) { | |
282 | /* Can't drop from default group */ | |
283 | if (rdtgrp == &rdtgroup_default) { | |
284 | ret = -EINVAL; | |
a2584e1d | 285 | goto unlock; |
12e0110c TL |
286 | } |
287 | /* Give any dropped cpus to rdtgroup_default */ | |
288 | cpumask_or(&rdtgroup_default.cpu_mask, | |
289 | &rdtgroup_default.cpu_mask, tmpmask); | |
0efc89be | 290 | rdt_update_closid(tmpmask, &rdtgroup_default.closid); |
12e0110c TL |
291 | } |
292 | ||
293 | /* | |
294 | * If we added cpus, remove them from previous group that owned them | |
295 | * and update per-cpu closid | |
296 | */ | |
297 | cpumask_andnot(tmpmask, newmask, &rdtgrp->cpu_mask); | |
298 | if (cpumask_weight(tmpmask)) { | |
299 | list_for_each_entry(r, &rdt_all_groups, rdtgroup_list) { | |
300 | if (r == rdtgrp) | |
301 | continue; | |
302 | cpumask_andnot(&r->cpu_mask, &r->cpu_mask, tmpmask); | |
303 | } | |
0efc89be | 304 | rdt_update_closid(tmpmask, &rdtgrp->closid); |
12e0110c TL |
305 | } |
306 | ||
307 | /* Done pushing/pulling - update this group with new mask */ | |
308 | cpumask_copy(&rdtgrp->cpu_mask, newmask); | |
309 | ||
12e0110c TL |
310 | unlock: |
311 | rdtgroup_kn_unlock(of->kn); | |
312 | free_cpumask_var(tmpmask); | |
313 | free_cpumask_var(newmask); | |
314 | ||
315 | return ret ?: nbytes; | |
316 | } | |
317 | ||
e02737d5 FY |
318 | struct task_move_callback { |
319 | struct callback_head work; | |
320 | struct rdtgroup *rdtgrp; | |
321 | }; | |
322 | ||
323 | static void move_myself(struct callback_head *head) | |
324 | { | |
325 | struct task_move_callback *callback; | |
326 | struct rdtgroup *rdtgrp; | |
327 | ||
328 | callback = container_of(head, struct task_move_callback, work); | |
329 | rdtgrp = callback->rdtgrp; | |
330 | ||
331 | /* | |
332 | * If resource group was deleted before this task work callback | |
333 | * was invoked, then assign the task to root group and free the | |
334 | * resource group. | |
335 | */ | |
336 | if (atomic_dec_and_test(&rdtgrp->waitcount) && | |
337 | (rdtgrp->flags & RDT_DELETED)) { | |
338 | current->closid = 0; | |
339 | kfree(rdtgrp); | |
340 | } | |
341 | ||
74fcdae1 | 342 | preempt_disable(); |
4f341a5e FY |
343 | /* update PQR_ASSOC MSR to make resource group go into effect */ |
344 | intel_rdt_sched_in(); | |
74fcdae1 | 345 | preempt_enable(); |
4f341a5e | 346 | |
e02737d5 FY |
347 | kfree(callback); |
348 | } | |
349 | ||
350 | static int __rdtgroup_move_task(struct task_struct *tsk, | |
351 | struct rdtgroup *rdtgrp) | |
352 | { | |
353 | struct task_move_callback *callback; | |
354 | int ret; | |
355 | ||
356 | callback = kzalloc(sizeof(*callback), GFP_KERNEL); | |
357 | if (!callback) | |
358 | return -ENOMEM; | |
359 | callback->work.func = move_myself; | |
360 | callback->rdtgrp = rdtgrp; | |
361 | ||
362 | /* | |
363 | * Take a refcount, so rdtgrp cannot be freed before the | |
364 | * callback has been invoked. | |
365 | */ | |
366 | atomic_inc(&rdtgrp->waitcount); | |
367 | ret = task_work_add(tsk, &callback->work, true); | |
368 | if (ret) { | |
369 | /* | |
370 | * Task is exiting. Drop the refcount and free the callback. | |
371 | * No need to check the refcount as the group cannot be | |
372 | * deleted before the write function unlocks rdtgroup_mutex. | |
373 | */ | |
374 | atomic_dec(&rdtgrp->waitcount); | |
375 | kfree(callback); | |
376 | } else { | |
377 | tsk->closid = rdtgrp->closid; | |
378 | } | |
379 | return ret; | |
380 | } | |
381 | ||
382 | static int rdtgroup_task_write_permission(struct task_struct *task, | |
383 | struct kernfs_open_file *of) | |
384 | { | |
385 | const struct cred *tcred = get_task_cred(task); | |
386 | const struct cred *cred = current_cred(); | |
387 | int ret = 0; | |
388 | ||
389 | /* | |
390 | * Even if we're attaching all tasks in the thread group, we only | |
391 | * need to check permissions on one of them. | |
392 | */ | |
393 | if (!uid_eq(cred->euid, GLOBAL_ROOT_UID) && | |
394 | !uid_eq(cred->euid, tcred->uid) && | |
395 | !uid_eq(cred->euid, tcred->suid)) | |
396 | ret = -EPERM; | |
397 | ||
398 | put_cred(tcred); | |
399 | return ret; | |
400 | } | |
401 | ||
402 | static int rdtgroup_move_task(pid_t pid, struct rdtgroup *rdtgrp, | |
403 | struct kernfs_open_file *of) | |
404 | { | |
405 | struct task_struct *tsk; | |
406 | int ret; | |
407 | ||
408 | rcu_read_lock(); | |
409 | if (pid) { | |
410 | tsk = find_task_by_vpid(pid); | |
411 | if (!tsk) { | |
412 | rcu_read_unlock(); | |
413 | return -ESRCH; | |
414 | } | |
415 | } else { | |
416 | tsk = current; | |
417 | } | |
418 | ||
419 | get_task_struct(tsk); | |
420 | rcu_read_unlock(); | |
421 | ||
422 | ret = rdtgroup_task_write_permission(tsk, of); | |
423 | if (!ret) | |
424 | ret = __rdtgroup_move_task(tsk, rdtgrp); | |
425 | ||
426 | put_task_struct(tsk); | |
427 | return ret; | |
428 | } | |
429 | ||
430 | static ssize_t rdtgroup_tasks_write(struct kernfs_open_file *of, | |
431 | char *buf, size_t nbytes, loff_t off) | |
432 | { | |
433 | struct rdtgroup *rdtgrp; | |
434 | int ret = 0; | |
435 | pid_t pid; | |
436 | ||
437 | if (kstrtoint(strstrip(buf), 0, &pid) || pid < 0) | |
438 | return -EINVAL; | |
439 | rdtgrp = rdtgroup_kn_lock_live(of->kn); | |
440 | ||
441 | if (rdtgrp) | |
442 | ret = rdtgroup_move_task(pid, rdtgrp, of); | |
443 | else | |
444 | ret = -ENOENT; | |
445 | ||
446 | rdtgroup_kn_unlock(of->kn); | |
447 | ||
448 | return ret ?: nbytes; | |
449 | } | |
450 | ||
451 | static void show_rdt_tasks(struct rdtgroup *r, struct seq_file *s) | |
452 | { | |
453 | struct task_struct *p, *t; | |
454 | ||
455 | rcu_read_lock(); | |
456 | for_each_process_thread(p, t) { | |
457 | if (t->closid == r->closid) | |
458 | seq_printf(s, "%d\n", t->pid); | |
459 | } | |
460 | rcu_read_unlock(); | |
461 | } | |
462 | ||
463 | static int rdtgroup_tasks_show(struct kernfs_open_file *of, | |
464 | struct seq_file *s, void *v) | |
465 | { | |
466 | struct rdtgroup *rdtgrp; | |
467 | int ret = 0; | |
468 | ||
469 | rdtgrp = rdtgroup_kn_lock_live(of->kn); | |
470 | if (rdtgrp) | |
471 | show_rdt_tasks(rdtgrp, s); | |
472 | else | |
473 | ret = -ENOENT; | |
474 | rdtgroup_kn_unlock(of->kn); | |
475 | ||
476 | return ret; | |
477 | } | |
478 | ||
12e0110c TL |
479 | /* Files in each rdtgroup */ |
480 | static struct rftype rdtgroup_base_files[] = { | |
481 | { | |
482 | .name = "cpus", | |
483 | .mode = 0644, | |
484 | .kf_ops = &rdtgroup_kf_single_ops, | |
485 | .write = rdtgroup_cpus_write, | |
486 | .seq_show = rdtgroup_cpus_show, | |
487 | }, | |
4ffa3c97 JO |
488 | { |
489 | .name = "cpus_list", | |
490 | .mode = 0644, | |
491 | .kf_ops = &rdtgroup_kf_single_ops, | |
492 | .write = rdtgroup_cpus_write, | |
493 | .seq_show = rdtgroup_cpus_show, | |
494 | .flags = RFTYPE_FLAGS_CPUS_LIST, | |
495 | }, | |
e02737d5 FY |
496 | { |
497 | .name = "tasks", | |
498 | .mode = 0644, | |
499 | .kf_ops = &rdtgroup_kf_single_ops, | |
500 | .write = rdtgroup_tasks_write, | |
501 | .seq_show = rdtgroup_tasks_show, | |
502 | }, | |
60ec2440 TL |
503 | { |
504 | .name = "schemata", | |
505 | .mode = 0644, | |
506 | .kf_ops = &rdtgroup_kf_single_ops, | |
507 | .write = rdtgroup_schemata_write, | |
508 | .seq_show = rdtgroup_schemata_show, | |
509 | }, | |
12e0110c TL |
510 | }; |
511 | ||
4e978d06 FY |
512 | static int rdt_num_closids_show(struct kernfs_open_file *of, |
513 | struct seq_file *seq, void *v) | |
514 | { | |
515 | struct rdt_resource *r = of->kn->parent->priv; | |
516 | ||
517 | seq_printf(seq, "%d\n", r->num_closid); | |
4e978d06 FY |
518 | return 0; |
519 | } | |
520 | ||
2545e9f5 | 521 | static int rdt_default_ctrl_show(struct kernfs_open_file *of, |
4e978d06 FY |
522 | struct seq_file *seq, void *v) |
523 | { | |
524 | struct rdt_resource *r = of->kn->parent->priv; | |
525 | ||
2545e9f5 | 526 | seq_printf(seq, "%x\n", r->default_ctrl); |
4e978d06 FY |
527 | return 0; |
528 | } | |
529 | ||
53a114a6 SL |
530 | static int rdt_min_cbm_bits_show(struct kernfs_open_file *of, |
531 | struct seq_file *seq, void *v) | |
532 | { | |
533 | struct rdt_resource *r = of->kn->parent->priv; | |
534 | ||
d3e11b4d | 535 | seq_printf(seq, "%u\n", r->cache.min_cbm_bits); |
db69ef65 VS |
536 | return 0; |
537 | } | |
538 | ||
539 | static int rdt_min_bw_show(struct kernfs_open_file *of, | |
540 | struct seq_file *seq, void *v) | |
541 | { | |
542 | struct rdt_resource *r = of->kn->parent->priv; | |
53a114a6 | 543 | |
db69ef65 VS |
544 | seq_printf(seq, "%u\n", r->membw.min_bw); |
545 | return 0; | |
546 | } | |
547 | ||
548 | static int rdt_bw_gran_show(struct kernfs_open_file *of, | |
549 | struct seq_file *seq, void *v) | |
550 | { | |
551 | struct rdt_resource *r = of->kn->parent->priv; | |
552 | ||
553 | seq_printf(seq, "%u\n", r->membw.bw_gran); | |
554 | return 0; | |
555 | } | |
556 | ||
557 | static int rdt_delay_linear_show(struct kernfs_open_file *of, | |
558 | struct seq_file *seq, void *v) | |
559 | { | |
560 | struct rdt_resource *r = of->kn->parent->priv; | |
561 | ||
562 | seq_printf(seq, "%u\n", r->membw.delay_linear); | |
53a114a6 SL |
563 | return 0; |
564 | } | |
565 | ||
4e978d06 | 566 | /* rdtgroup information files for one cache resource. */ |
6a507a6a | 567 | static struct rftype res_cache_info_files[] = { |
4e978d06 FY |
568 | { |
569 | .name = "num_closids", | |
570 | .mode = 0444, | |
571 | .kf_ops = &rdtgroup_kf_single_ops, | |
572 | .seq_show = rdt_num_closids_show, | |
573 | }, | |
574 | { | |
575 | .name = "cbm_mask", | |
576 | .mode = 0444, | |
577 | .kf_ops = &rdtgroup_kf_single_ops, | |
2545e9f5 | 578 | .seq_show = rdt_default_ctrl_show, |
4e978d06 | 579 | }, |
53a114a6 SL |
580 | { |
581 | .name = "min_cbm_bits", | |
582 | .mode = 0444, | |
583 | .kf_ops = &rdtgroup_kf_single_ops, | |
584 | .seq_show = rdt_min_cbm_bits_show, | |
585 | }, | |
4e978d06 FY |
586 | }; |
587 | ||
db69ef65 VS |
588 | /* rdtgroup information files for memory bandwidth. */ |
589 | static struct rftype res_mba_info_files[] = { | |
590 | { | |
591 | .name = "num_closids", | |
592 | .mode = 0444, | |
593 | .kf_ops = &rdtgroup_kf_single_ops, | |
594 | .seq_show = rdt_num_closids_show, | |
595 | }, | |
596 | { | |
597 | .name = "min_bandwidth", | |
598 | .mode = 0444, | |
599 | .kf_ops = &rdtgroup_kf_single_ops, | |
600 | .seq_show = rdt_min_bw_show, | |
601 | }, | |
602 | { | |
603 | .name = "bandwidth_gran", | |
604 | .mode = 0444, | |
605 | .kf_ops = &rdtgroup_kf_single_ops, | |
606 | .seq_show = rdt_bw_gran_show, | |
607 | }, | |
608 | { | |
609 | .name = "delay_linear", | |
610 | .mode = 0444, | |
611 | .kf_ops = &rdtgroup_kf_single_ops, | |
612 | .seq_show = rdt_delay_linear_show, | |
613 | }, | |
614 | }; | |
615 | ||
616 | void rdt_get_mba_infofile(struct rdt_resource *r) | |
617 | { | |
618 | r->info_files = res_mba_info_files; | |
619 | r->nr_info_files = ARRAY_SIZE(res_mba_info_files); | |
620 | } | |
621 | ||
6a507a6a VS |
622 | void rdt_get_cache_infofile(struct rdt_resource *r) |
623 | { | |
624 | r->info_files = res_cache_info_files; | |
625 | r->nr_info_files = ARRAY_SIZE(res_cache_info_files); | |
626 | } | |
627 | ||
4e978d06 FY |
628 | static int rdtgroup_create_info_dir(struct kernfs_node *parent_kn) |
629 | { | |
630 | struct kernfs_node *kn_subdir; | |
6a507a6a | 631 | struct rftype *res_info_files; |
4e978d06 | 632 | struct rdt_resource *r; |
6a507a6a | 633 | int ret, len; |
4e978d06 FY |
634 | |
635 | /* create the directory */ | |
636 | kn_info = kernfs_create_dir(parent_kn, "info", parent_kn->mode, NULL); | |
637 | if (IS_ERR(kn_info)) | |
638 | return PTR_ERR(kn_info); | |
639 | kernfs_get(kn_info); | |
640 | ||
641 | for_each_enabled_rdt_resource(r) { | |
642 | kn_subdir = kernfs_create_dir(kn_info, r->name, | |
643 | kn_info->mode, r); | |
644 | if (IS_ERR(kn_subdir)) { | |
645 | ret = PTR_ERR(kn_subdir); | |
646 | goto out_destroy; | |
647 | } | |
648 | kernfs_get(kn_subdir); | |
649 | ret = rdtgroup_kn_set_ugid(kn_subdir); | |
650 | if (ret) | |
651 | goto out_destroy; | |
6a507a6a VS |
652 | |
653 | res_info_files = r->info_files; | |
654 | len = r->nr_info_files; | |
655 | ||
656 | ret = rdtgroup_add_files(kn_subdir, res_info_files, len); | |
4e978d06 FY |
657 | if (ret) |
658 | goto out_destroy; | |
659 | kernfs_activate(kn_subdir); | |
660 | } | |
661 | ||
662 | /* | |
663 | * This extra ref will be put in kernfs_remove() and guarantees | |
664 | * that @rdtgrp->kn is always accessible. | |
665 | */ | |
666 | kernfs_get(kn_info); | |
667 | ||
668 | ret = rdtgroup_kn_set_ugid(kn_info); | |
669 | if (ret) | |
670 | goto out_destroy; | |
671 | ||
672 | kernfs_activate(kn_info); | |
673 | ||
674 | return 0; | |
675 | ||
676 | out_destroy: | |
677 | kernfs_remove(kn_info); | |
678 | return ret; | |
679 | } | |
680 | ||
5ff193fb FY |
681 | static void l3_qos_cfg_update(void *arg) |
682 | { | |
683 | bool *enable = arg; | |
684 | ||
685 | wrmsrl(IA32_L3_QOS_CFG, *enable ? L3_QOS_CDP_ENABLE : 0ULL); | |
686 | } | |
687 | ||
688 | static int set_l3_qos_cfg(struct rdt_resource *r, bool enable) | |
689 | { | |
690 | cpumask_var_t cpu_mask; | |
691 | struct rdt_domain *d; | |
692 | int cpu; | |
693 | ||
694 | if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL)) | |
695 | return -ENOMEM; | |
696 | ||
697 | list_for_each_entry(d, &r->domains, list) { | |
698 | /* Pick one CPU from each domain instance to update MSR */ | |
699 | cpumask_set_cpu(cpumask_any(&d->cpu_mask), cpu_mask); | |
700 | } | |
701 | cpu = get_cpu(); | |
702 | /* Update QOS_CFG MSR on this cpu if it's in cpu_mask. */ | |
703 | if (cpumask_test_cpu(cpu, cpu_mask)) | |
704 | l3_qos_cfg_update(&enable); | |
705 | /* Update QOS_CFG MSR on all other cpus in cpu_mask. */ | |
706 | smp_call_function_many(cpu_mask, l3_qos_cfg_update, &enable, 1); | |
707 | put_cpu(); | |
708 | ||
709 | free_cpumask_var(cpu_mask); | |
710 | ||
711 | return 0; | |
712 | } | |
713 | ||
714 | static int cdp_enable(void) | |
715 | { | |
716 | struct rdt_resource *r_l3data = &rdt_resources_all[RDT_RESOURCE_L3DATA]; | |
717 | struct rdt_resource *r_l3code = &rdt_resources_all[RDT_RESOURCE_L3CODE]; | |
718 | struct rdt_resource *r_l3 = &rdt_resources_all[RDT_RESOURCE_L3]; | |
719 | int ret; | |
720 | ||
721 | if (!r_l3->capable || !r_l3data->capable || !r_l3code->capable) | |
722 | return -EINVAL; | |
723 | ||
724 | ret = set_l3_qos_cfg(r_l3, true); | |
725 | if (!ret) { | |
726 | r_l3->enabled = false; | |
727 | r_l3data->enabled = true; | |
728 | r_l3code->enabled = true; | |
729 | } | |
730 | return ret; | |
731 | } | |
732 | ||
733 | static void cdp_disable(void) | |
734 | { | |
735 | struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_L3]; | |
736 | ||
737 | r->enabled = r->capable; | |
738 | ||
739 | if (rdt_resources_all[RDT_RESOURCE_L3DATA].enabled) { | |
740 | rdt_resources_all[RDT_RESOURCE_L3DATA].enabled = false; | |
741 | rdt_resources_all[RDT_RESOURCE_L3CODE].enabled = false; | |
742 | set_l3_qos_cfg(r, false); | |
743 | } | |
744 | } | |
745 | ||
746 | static int parse_rdtgroupfs_options(char *data) | |
747 | { | |
748 | char *token, *o = data; | |
749 | int ret = 0; | |
750 | ||
751 | while ((token = strsep(&o, ",")) != NULL) { | |
752 | if (!*token) | |
753 | return -EINVAL; | |
754 | ||
755 | if (!strcmp(token, "cdp")) | |
756 | ret = cdp_enable(); | |
757 | } | |
758 | ||
759 | return ret; | |
760 | } | |
761 | ||
60cf5e10 FY |
762 | /* |
763 | * We don't allow rdtgroup directories to be created anywhere | |
764 | * except the root directory. Thus when looking for the rdtgroup | |
765 | * structure for a kernfs node we are either looking at a directory, | |
766 | * in which case the rdtgroup structure is pointed at by the "priv" | |
767 | * field, otherwise we have a file, and need only look to the parent | |
768 | * to find the rdtgroup. | |
769 | */ | |
770 | static struct rdtgroup *kernfs_to_rdtgroup(struct kernfs_node *kn) | |
771 | { | |
f57b3087 FY |
772 | if (kernfs_type(kn) == KERNFS_DIR) { |
773 | /* | |
774 | * All the resource directories use "kn->priv" | |
775 | * to point to the "struct rdtgroup" for the | |
776 | * resource. "info" and its subdirectories don't | |
777 | * have rdtgroup structures, so return NULL here. | |
778 | */ | |
779 | if (kn == kn_info || kn->parent == kn_info) | |
780 | return NULL; | |
781 | else | |
782 | return kn->priv; | |
783 | } else { | |
60cf5e10 | 784 | return kn->parent->priv; |
f57b3087 | 785 | } |
60cf5e10 FY |
786 | } |
787 | ||
788 | struct rdtgroup *rdtgroup_kn_lock_live(struct kernfs_node *kn) | |
789 | { | |
790 | struct rdtgroup *rdtgrp = kernfs_to_rdtgroup(kn); | |
791 | ||
f57b3087 FY |
792 | if (!rdtgrp) |
793 | return NULL; | |
794 | ||
60cf5e10 FY |
795 | atomic_inc(&rdtgrp->waitcount); |
796 | kernfs_break_active_protection(kn); | |
797 | ||
798 | mutex_lock(&rdtgroup_mutex); | |
799 | ||
800 | /* Was this group deleted while we waited? */ | |
801 | if (rdtgrp->flags & RDT_DELETED) | |
802 | return NULL; | |
803 | ||
804 | return rdtgrp; | |
805 | } | |
806 | ||
807 | void rdtgroup_kn_unlock(struct kernfs_node *kn) | |
808 | { | |
809 | struct rdtgroup *rdtgrp = kernfs_to_rdtgroup(kn); | |
810 | ||
f57b3087 FY |
811 | if (!rdtgrp) |
812 | return; | |
813 | ||
60cf5e10 FY |
814 | mutex_unlock(&rdtgroup_mutex); |
815 | ||
816 | if (atomic_dec_and_test(&rdtgrp->waitcount) && | |
817 | (rdtgrp->flags & RDT_DELETED)) { | |
818 | kernfs_unbreak_active_protection(kn); | |
49ec8f5b | 819 | kernfs_put(rdtgrp->kn); |
60cf5e10 FY |
820 | kfree(rdtgrp); |
821 | } else { | |
822 | kernfs_unbreak_active_protection(kn); | |
823 | } | |
824 | } | |
825 | ||
5ff193fb FY |
826 | static struct dentry *rdt_mount(struct file_system_type *fs_type, |
827 | int flags, const char *unused_dev_name, | |
828 | void *data) | |
829 | { | |
830 | struct dentry *dentry; | |
831 | int ret; | |
832 | ||
833 | mutex_lock(&rdtgroup_mutex); | |
834 | /* | |
835 | * resctrl file system can only be mounted once. | |
836 | */ | |
837 | if (static_branch_unlikely(&rdt_enable_key)) { | |
838 | dentry = ERR_PTR(-EBUSY); | |
839 | goto out; | |
840 | } | |
841 | ||
842 | ret = parse_rdtgroupfs_options(data); | |
843 | if (ret) { | |
844 | dentry = ERR_PTR(ret); | |
845 | goto out_cdp; | |
846 | } | |
847 | ||
60cf5e10 FY |
848 | closid_init(); |
849 | ||
4e978d06 | 850 | ret = rdtgroup_create_info_dir(rdtgroup_default.kn); |
7bff0af5 SL |
851 | if (ret) { |
852 | dentry = ERR_PTR(ret); | |
4e978d06 | 853 | goto out_cdp; |
7bff0af5 | 854 | } |
4e978d06 | 855 | |
5ff193fb FY |
856 | dentry = kernfs_mount(fs_type, flags, rdt_root, |
857 | RDTGROUP_SUPER_MAGIC, NULL); | |
858 | if (IS_ERR(dentry)) | |
79298acc | 859 | goto out_destroy; |
5ff193fb FY |
860 | |
861 | static_branch_enable(&rdt_enable_key); | |
862 | goto out; | |
863 | ||
79298acc VS |
864 | out_destroy: |
865 | kernfs_remove(kn_info); | |
5ff193fb FY |
866 | out_cdp: |
867 | cdp_disable(); | |
868 | out: | |
869 | mutex_unlock(&rdtgroup_mutex); | |
870 | ||
871 | return dentry; | |
872 | } | |
873 | ||
2545e9f5 | 874 | static int reset_all_ctrls(struct rdt_resource *r) |
5ff193fb FY |
875 | { |
876 | struct msr_param msr_param; | |
877 | cpumask_var_t cpu_mask; | |
878 | struct rdt_domain *d; | |
879 | int i, cpu; | |
880 | ||
881 | if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL)) | |
882 | return -ENOMEM; | |
883 | ||
884 | msr_param.res = r; | |
885 | msr_param.low = 0; | |
886 | msr_param.high = r->num_closid; | |
887 | ||
888 | /* | |
889 | * Disable resource control for this resource by setting all | |
890 | * CBMs in all domains to the maximum mask value. Pick one CPU | |
891 | * from each domain to update the MSRs below. | |
892 | */ | |
893 | list_for_each_entry(d, &r->domains, list) { | |
894 | cpumask_set_cpu(cpumask_any(&d->cpu_mask), cpu_mask); | |
895 | ||
896 | for (i = 0; i < r->num_closid; i++) | |
2545e9f5 | 897 | d->ctrl_val[i] = r->default_ctrl; |
5ff193fb FY |
898 | } |
899 | cpu = get_cpu(); | |
900 | /* Update CBM on this cpu if it's in cpu_mask. */ | |
901 | if (cpumask_test_cpu(cpu, cpu_mask)) | |
2545e9f5 | 902 | rdt_ctrl_update(&msr_param); |
5ff193fb | 903 | /* Update CBM on all other cpus in cpu_mask. */ |
2545e9f5 | 904 | smp_call_function_many(cpu_mask, rdt_ctrl_update, &msr_param, 1); |
5ff193fb FY |
905 | put_cpu(); |
906 | ||
907 | free_cpumask_var(cpu_mask); | |
908 | ||
909 | return 0; | |
910 | } | |
911 | ||
4e978d06 | 912 | /* |
0efc89be FY |
913 | * Move tasks from one to the other group. If @from is NULL, then all tasks |
914 | * in the systems are moved unconditionally (used for teardown). | |
915 | * | |
916 | * If @mask is not NULL the cpus on which moved tasks are running are set | |
917 | * in that mask so the update smp function call is restricted to affected | |
918 | * cpus. | |
4e978d06 | 919 | */ |
0efc89be FY |
920 | static void rdt_move_group_tasks(struct rdtgroup *from, struct rdtgroup *to, |
921 | struct cpumask *mask) | |
4e978d06 | 922 | { |
e02737d5 FY |
923 | struct task_struct *p, *t; |
924 | ||
e02737d5 | 925 | read_lock(&tasklist_lock); |
0efc89be FY |
926 | for_each_process_thread(p, t) { |
927 | if (!from || t->closid == from->closid) { | |
928 | t->closid = to->closid; | |
929 | #ifdef CONFIG_SMP | |
930 | /* | |
931 | * This is safe on x86 w/o barriers as the ordering | |
932 | * of writing to task_cpu() and t->on_cpu is | |
933 | * reverse to the reading here. The detection is | |
934 | * inaccurate as tasks might move or schedule | |
935 | * before the smp function call takes place. In | |
936 | * such a case the function call is pointless, but | |
937 | * there is no other side effect. | |
938 | */ | |
939 | if (mask && t->on_cpu) | |
940 | cpumask_set_cpu(task_cpu(t), mask); | |
941 | #endif | |
942 | } | |
943 | } | |
e02737d5 | 944 | read_unlock(&tasklist_lock); |
0efc89be FY |
945 | } |
946 | ||
947 | /* | |
948 | * Forcibly remove all of subdirectories under root. | |
949 | */ | |
950 | static void rmdir_all_sub(void) | |
951 | { | |
952 | struct rdtgroup *rdtgrp, *tmp; | |
953 | ||
954 | /* Move all tasks to the default resource group */ | |
955 | rdt_move_group_tasks(NULL, &rdtgroup_default, NULL); | |
60cf5e10 | 956 | |
60cf5e10 FY |
957 | list_for_each_entry_safe(rdtgrp, tmp, &rdt_all_groups, rdtgroup_list) { |
958 | /* Remove each rdtgroup other than root */ | |
959 | if (rdtgrp == &rdtgroup_default) | |
960 | continue; | |
c7cc0cc1 FY |
961 | |
962 | /* | |
963 | * Give any CPUs back to the default group. We cannot copy | |
964 | * cpu_online_mask because a CPU might have executed the | |
965 | * offline callback already, but is still marked online. | |
966 | */ | |
967 | cpumask_or(&rdtgroup_default.cpu_mask, | |
968 | &rdtgroup_default.cpu_mask, &rdtgrp->cpu_mask); | |
969 | ||
60cf5e10 FY |
970 | kernfs_remove(rdtgrp->kn); |
971 | list_del(&rdtgrp->rdtgroup_list); | |
972 | kfree(rdtgrp); | |
973 | } | |
0efc89be FY |
974 | /* Notify online CPUs to update per cpu storage and PQR_ASSOC MSR */ |
975 | get_online_cpus(); | |
976 | rdt_update_closid(cpu_online_mask, &rdtgroup_default.closid); | |
977 | put_online_cpus(); | |
978 | ||
4e978d06 FY |
979 | kernfs_remove(kn_info); |
980 | } | |
981 | ||
5ff193fb FY |
982 | static void rdt_kill_sb(struct super_block *sb) |
983 | { | |
984 | struct rdt_resource *r; | |
985 | ||
986 | mutex_lock(&rdtgroup_mutex); | |
987 | ||
988 | /*Put everything back to default values. */ | |
989 | for_each_enabled_rdt_resource(r) | |
2545e9f5 | 990 | reset_all_ctrls(r); |
5ff193fb | 991 | cdp_disable(); |
4e978d06 | 992 | rmdir_all_sub(); |
5ff193fb FY |
993 | static_branch_disable(&rdt_enable_key); |
994 | kernfs_kill_sb(sb); | |
995 | mutex_unlock(&rdtgroup_mutex); | |
996 | } | |
997 | ||
998 | static struct file_system_type rdt_fs_type = { | |
999 | .name = "resctrl", | |
1000 | .mount = rdt_mount, | |
1001 | .kill_sb = rdt_kill_sb, | |
1002 | }; | |
1003 | ||
60cf5e10 FY |
1004 | static int rdtgroup_mkdir(struct kernfs_node *parent_kn, const char *name, |
1005 | umode_t mode) | |
1006 | { | |
1007 | struct rdtgroup *parent, *rdtgrp; | |
1008 | struct kernfs_node *kn; | |
1009 | int ret, closid; | |
1010 | ||
1011 | /* Only allow mkdir in the root directory */ | |
1012 | if (parent_kn != rdtgroup_default.kn) | |
1013 | return -EPERM; | |
1014 | ||
1015 | /* Do not accept '\n' to avoid unparsable situation. */ | |
1016 | if (strchr(name, '\n')) | |
1017 | return -EINVAL; | |
1018 | ||
1019 | parent = rdtgroup_kn_lock_live(parent_kn); | |
1020 | if (!parent) { | |
1021 | ret = -ENODEV; | |
1022 | goto out_unlock; | |
1023 | } | |
1024 | ||
1025 | ret = closid_alloc(); | |
1026 | if (ret < 0) | |
1027 | goto out_unlock; | |
1028 | closid = ret; | |
1029 | ||
1030 | /* allocate the rdtgroup. */ | |
1031 | rdtgrp = kzalloc(sizeof(*rdtgrp), GFP_KERNEL); | |
1032 | if (!rdtgrp) { | |
1033 | ret = -ENOSPC; | |
1034 | goto out_closid_free; | |
1035 | } | |
1036 | rdtgrp->closid = closid; | |
1037 | list_add(&rdtgrp->rdtgroup_list, &rdt_all_groups); | |
1038 | ||
1039 | /* kernfs creates the directory for rdtgrp */ | |
1040 | kn = kernfs_create_dir(parent->kn, name, mode, rdtgrp); | |
1041 | if (IS_ERR(kn)) { | |
1042 | ret = PTR_ERR(kn); | |
1043 | goto out_cancel_ref; | |
1044 | } | |
1045 | rdtgrp->kn = kn; | |
1046 | ||
1047 | /* | |
1048 | * kernfs_remove() will drop the reference count on "kn" which | |
1049 | * will free it. But we still need it to stick around for the | |
1050 | * rdtgroup_kn_unlock(kn} call below. Take one extra reference | |
1051 | * here, which will be dropped inside rdtgroup_kn_unlock(). | |
1052 | */ | |
1053 | kernfs_get(kn); | |
1054 | ||
1055 | ret = rdtgroup_kn_set_ugid(kn); | |
1056 | if (ret) | |
1057 | goto out_destroy; | |
1058 | ||
12e0110c TL |
1059 | ret = rdtgroup_add_files(kn, rdtgroup_base_files, |
1060 | ARRAY_SIZE(rdtgroup_base_files)); | |
1061 | if (ret) | |
1062 | goto out_destroy; | |
1063 | ||
60cf5e10 FY |
1064 | kernfs_activate(kn); |
1065 | ||
1066 | ret = 0; | |
1067 | goto out_unlock; | |
1068 | ||
1069 | out_destroy: | |
1070 | kernfs_remove(rdtgrp->kn); | |
1071 | out_cancel_ref: | |
1072 | list_del(&rdtgrp->rdtgroup_list); | |
1073 | kfree(rdtgrp); | |
1074 | out_closid_free: | |
1075 | closid_free(closid); | |
1076 | out_unlock: | |
1077 | rdtgroup_kn_unlock(parent_kn); | |
1078 | return ret; | |
1079 | } | |
1080 | ||
1081 | static int rdtgroup_rmdir(struct kernfs_node *kn) | |
1082 | { | |
0efc89be | 1083 | int ret, cpu, closid = rdtgroup_default.closid; |
60cf5e10 | 1084 | struct rdtgroup *rdtgrp; |
0efc89be FY |
1085 | cpumask_var_t tmpmask; |
1086 | ||
1087 | if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL)) | |
1088 | return -ENOMEM; | |
60cf5e10 FY |
1089 | |
1090 | rdtgrp = rdtgroup_kn_lock_live(kn); | |
1091 | if (!rdtgrp) { | |
0efc89be FY |
1092 | ret = -EPERM; |
1093 | goto out; | |
60cf5e10 FY |
1094 | } |
1095 | ||
e02737d5 | 1096 | /* Give any tasks back to the default group */ |
0efc89be | 1097 | rdt_move_group_tasks(rdtgrp, &rdtgroup_default, tmpmask); |
e02737d5 | 1098 | |
12e0110c TL |
1099 | /* Give any CPUs back to the default group */ |
1100 | cpumask_or(&rdtgroup_default.cpu_mask, | |
1101 | &rdtgroup_default.cpu_mask, &rdtgrp->cpu_mask); | |
0efc89be FY |
1102 | |
1103 | /* Update per cpu closid of the moved CPUs first */ | |
1104 | for_each_cpu(cpu, &rdtgrp->cpu_mask) | |
1105 | per_cpu(cpu_closid, cpu) = closid; | |
1106 | /* | |
1107 | * Update the MSR on moved CPUs and CPUs which have moved | |
1108 | * task running on them. | |
1109 | */ | |
1110 | cpumask_or(tmpmask, tmpmask, &rdtgrp->cpu_mask); | |
1111 | rdt_update_closid(tmpmask, NULL); | |
12e0110c | 1112 | |
60cf5e10 FY |
1113 | rdtgrp->flags = RDT_DELETED; |
1114 | closid_free(rdtgrp->closid); | |
1115 | list_del(&rdtgrp->rdtgroup_list); | |
1116 | ||
1117 | /* | |
1118 | * one extra hold on this, will drop when we kfree(rdtgrp) | |
1119 | * in rdtgroup_kn_unlock() | |
1120 | */ | |
1121 | kernfs_get(kn); | |
1122 | kernfs_remove(rdtgrp->kn); | |
0efc89be FY |
1123 | ret = 0; |
1124 | out: | |
60cf5e10 | 1125 | rdtgroup_kn_unlock(kn); |
0efc89be FY |
1126 | free_cpumask_var(tmpmask); |
1127 | return ret; | |
60cf5e10 FY |
1128 | } |
1129 | ||
76ae054c SL |
1130 | static int rdtgroup_show_options(struct seq_file *seq, struct kernfs_root *kf) |
1131 | { | |
1132 | if (rdt_resources_all[RDT_RESOURCE_L3DATA].enabled) | |
1133 | seq_puts(seq, ",cdp"); | |
1134 | return 0; | |
1135 | } | |
1136 | ||
5ff193fb | 1137 | static struct kernfs_syscall_ops rdtgroup_kf_syscall_ops = { |
76ae054c SL |
1138 | .mkdir = rdtgroup_mkdir, |
1139 | .rmdir = rdtgroup_rmdir, | |
1140 | .show_options = rdtgroup_show_options, | |
5ff193fb FY |
1141 | }; |
1142 | ||
1143 | static int __init rdtgroup_setup_root(void) | |
1144 | { | |
12e0110c TL |
1145 | int ret; |
1146 | ||
5ff193fb FY |
1147 | rdt_root = kernfs_create_root(&rdtgroup_kf_syscall_ops, |
1148 | KERNFS_ROOT_CREATE_DEACTIVATED, | |
1149 | &rdtgroup_default); | |
1150 | if (IS_ERR(rdt_root)) | |
1151 | return PTR_ERR(rdt_root); | |
1152 | ||
1153 | mutex_lock(&rdtgroup_mutex); | |
1154 | ||
1155 | rdtgroup_default.closid = 0; | |
1156 | list_add(&rdtgroup_default.rdtgroup_list, &rdt_all_groups); | |
1157 | ||
12e0110c TL |
1158 | ret = rdtgroup_add_files(rdt_root->kn, rdtgroup_base_files, |
1159 | ARRAY_SIZE(rdtgroup_base_files)); | |
1160 | if (ret) { | |
1161 | kernfs_destroy_root(rdt_root); | |
1162 | goto out; | |
1163 | } | |
1164 | ||
5ff193fb FY |
1165 | rdtgroup_default.kn = rdt_root->kn; |
1166 | kernfs_activate(rdtgroup_default.kn); | |
1167 | ||
12e0110c | 1168 | out: |
5ff193fb FY |
1169 | mutex_unlock(&rdtgroup_mutex); |
1170 | ||
12e0110c | 1171 | return ret; |
5ff193fb FY |
1172 | } |
1173 | ||
1174 | /* | |
1175 | * rdtgroup_init - rdtgroup initialization | |
1176 | * | |
1177 | * Setup resctrl file system including set up root, create mount point, | |
1178 | * register rdtgroup filesystem, and initialize files under root directory. | |
1179 | * | |
1180 | * Return: 0 on success or -errno | |
1181 | */ | |
1182 | int __init rdtgroup_init(void) | |
1183 | { | |
1184 | int ret = 0; | |
1185 | ||
1186 | ret = rdtgroup_setup_root(); | |
1187 | if (ret) | |
1188 | return ret; | |
1189 | ||
1190 | ret = sysfs_create_mount_point(fs_kobj, "resctrl"); | |
1191 | if (ret) | |
1192 | goto cleanup_root; | |
1193 | ||
1194 | ret = register_filesystem(&rdt_fs_type); | |
1195 | if (ret) | |
1196 | goto cleanup_mountpoint; | |
1197 | ||
1198 | return 0; | |
1199 | ||
1200 | cleanup_mountpoint: | |
1201 | sysfs_remove_mount_point(fs_kobj, "resctrl"); | |
1202 | cleanup_root: | |
1203 | kernfs_destroy_root(rdt_root); | |
1204 | ||
1205 | return ret; | |
1206 | } |