Merge tag 'input-for-v6.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor...
[platform/kernel/linux-starfive.git] / mm / hugetlb_cgroup.c
1 /*
2  *
3  * Copyright IBM Corporation, 2012
4  * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
5  *
6  * Cgroup v2
7  * Copyright (C) 2019 Red Hat, Inc.
8  * Author: Giuseppe Scrivano <gscrivan@redhat.com>
9  *
10  * This program is free software; you can redistribute it and/or modify it
11  * under the terms of version 2.1 of the GNU Lesser General Public License
12  * as published by the Free Software Foundation.
13  *
14  * This program is distributed in the hope that it would be useful, but
15  * WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
17  *
18  */
19
20 #include <linux/cgroup.h>
21 #include <linux/page_counter.h>
22 #include <linux/slab.h>
23 #include <linux/hugetlb.h>
24 #include <linux/hugetlb_cgroup.h>
25
26 #define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val))
27 #define MEMFILE_IDX(val)        (((val) >> 16) & 0xffff)
28 #define MEMFILE_ATTR(val)       ((val) & 0xffff)
29
30 static struct hugetlb_cgroup *root_h_cgroup __read_mostly;
31
32 static inline struct page_counter *
33 __hugetlb_cgroup_counter_from_cgroup(struct hugetlb_cgroup *h_cg, int idx,
34                                      bool rsvd)
35 {
36         if (rsvd)
37                 return &h_cg->rsvd_hugepage[idx];
38         return &h_cg->hugepage[idx];
39 }
40
41 static inline struct page_counter *
42 hugetlb_cgroup_counter_from_cgroup(struct hugetlb_cgroup *h_cg, int idx)
43 {
44         return __hugetlb_cgroup_counter_from_cgroup(h_cg, idx, false);
45 }
46
47 static inline struct page_counter *
48 hugetlb_cgroup_counter_from_cgroup_rsvd(struct hugetlb_cgroup *h_cg, int idx)
49 {
50         return __hugetlb_cgroup_counter_from_cgroup(h_cg, idx, true);
51 }
52
53 static inline
54 struct hugetlb_cgroup *hugetlb_cgroup_from_css(struct cgroup_subsys_state *s)
55 {
56         return s ? container_of(s, struct hugetlb_cgroup, css) : NULL;
57 }
58
59 static inline
60 struct hugetlb_cgroup *hugetlb_cgroup_from_task(struct task_struct *task)
61 {
62         return hugetlb_cgroup_from_css(task_css(task, hugetlb_cgrp_id));
63 }
64
65 static inline bool hugetlb_cgroup_is_root(struct hugetlb_cgroup *h_cg)
66 {
67         return (h_cg == root_h_cgroup);
68 }
69
70 static inline struct hugetlb_cgroup *
71 parent_hugetlb_cgroup(struct hugetlb_cgroup *h_cg)
72 {
73         return hugetlb_cgroup_from_css(h_cg->css.parent);
74 }
75
76 static inline bool hugetlb_cgroup_have_usage(struct hugetlb_cgroup *h_cg)
77 {
78         struct hstate *h;
79
80         for_each_hstate(h) {
81                 if (page_counter_read(
82                     hugetlb_cgroup_counter_from_cgroup(h_cg, hstate_index(h))))
83                         return true;
84         }
85         return false;
86 }
87
88 static void hugetlb_cgroup_init(struct hugetlb_cgroup *h_cgroup,
89                                 struct hugetlb_cgroup *parent_h_cgroup)
90 {
91         int idx;
92
93         for (idx = 0; idx < HUGE_MAX_HSTATE; idx++) {
94                 struct page_counter *fault_parent = NULL;
95                 struct page_counter *rsvd_parent = NULL;
96                 unsigned long limit;
97                 int ret;
98
99                 if (parent_h_cgroup) {
100                         fault_parent = hugetlb_cgroup_counter_from_cgroup(
101                                 parent_h_cgroup, idx);
102                         rsvd_parent = hugetlb_cgroup_counter_from_cgroup_rsvd(
103                                 parent_h_cgroup, idx);
104                 }
105                 page_counter_init(hugetlb_cgroup_counter_from_cgroup(h_cgroup,
106                                                                      idx),
107                                   fault_parent);
108                 page_counter_init(
109                         hugetlb_cgroup_counter_from_cgroup_rsvd(h_cgroup, idx),
110                         rsvd_parent);
111
112                 limit = round_down(PAGE_COUNTER_MAX,
113                                    pages_per_huge_page(&hstates[idx]));
114
115                 ret = page_counter_set_max(
116                         hugetlb_cgroup_counter_from_cgroup(h_cgroup, idx),
117                         limit);
118                 VM_BUG_ON(ret);
119                 ret = page_counter_set_max(
120                         hugetlb_cgroup_counter_from_cgroup_rsvd(h_cgroup, idx),
121                         limit);
122                 VM_BUG_ON(ret);
123         }
124 }
125
126 static void hugetlb_cgroup_free(struct hugetlb_cgroup *h_cgroup)
127 {
128         int node;
129
130         for_each_node(node)
131                 kfree(h_cgroup->nodeinfo[node]);
132         kfree(h_cgroup);
133 }
134
135 static struct cgroup_subsys_state *
136 hugetlb_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
137 {
138         struct hugetlb_cgroup *parent_h_cgroup = hugetlb_cgroup_from_css(parent_css);
139         struct hugetlb_cgroup *h_cgroup;
140         int node;
141
142         h_cgroup = kzalloc(struct_size(h_cgroup, nodeinfo, nr_node_ids),
143                            GFP_KERNEL);
144
145         if (!h_cgroup)
146                 return ERR_PTR(-ENOMEM);
147
148         if (!parent_h_cgroup)
149                 root_h_cgroup = h_cgroup;
150
151         /*
152          * TODO: this routine can waste much memory for nodes which will
153          * never be onlined. It's better to use memory hotplug callback
154          * function.
155          */
156         for_each_node(node) {
157                 /* Set node_to_alloc to NUMA_NO_NODE for offline nodes. */
158                 int node_to_alloc =
159                         node_state(node, N_NORMAL_MEMORY) ? node : NUMA_NO_NODE;
160                 h_cgroup->nodeinfo[node] =
161                         kzalloc_node(sizeof(struct hugetlb_cgroup_per_node),
162                                      GFP_KERNEL, node_to_alloc);
163                 if (!h_cgroup->nodeinfo[node])
164                         goto fail_alloc_nodeinfo;
165         }
166
167         hugetlb_cgroup_init(h_cgroup, parent_h_cgroup);
168         return &h_cgroup->css;
169
170 fail_alloc_nodeinfo:
171         hugetlb_cgroup_free(h_cgroup);
172         return ERR_PTR(-ENOMEM);
173 }
174
175 static void hugetlb_cgroup_css_free(struct cgroup_subsys_state *css)
176 {
177         hugetlb_cgroup_free(hugetlb_cgroup_from_css(css));
178 }
179
180 /*
181  * Should be called with hugetlb_lock held.
182  * Since we are holding hugetlb_lock, pages cannot get moved from
183  * active list or uncharged from the cgroup, So no need to get
184  * page reference and test for page active here. This function
185  * cannot fail.
186  */
187 static void hugetlb_cgroup_move_parent(int idx, struct hugetlb_cgroup *h_cg,
188                                        struct page *page)
189 {
190         unsigned int nr_pages;
191         struct page_counter *counter;
192         struct hugetlb_cgroup *page_hcg;
193         struct hugetlb_cgroup *parent = parent_hugetlb_cgroup(h_cg);
194         struct folio *folio = page_folio(page);
195
196         page_hcg = hugetlb_cgroup_from_folio(folio);
197         /*
198          * We can have pages in active list without any cgroup
199          * ie, hugepage with less than 3 pages. We can safely
200          * ignore those pages.
201          */
202         if (!page_hcg || page_hcg != h_cg)
203                 goto out;
204
205         nr_pages = compound_nr(page);
206         if (!parent) {
207                 parent = root_h_cgroup;
208                 /* root has no limit */
209                 page_counter_charge(&parent->hugepage[idx], nr_pages);
210         }
211         counter = &h_cg->hugepage[idx];
212         /* Take the pages off the local counter */
213         page_counter_cancel(counter, nr_pages);
214
215         set_hugetlb_cgroup(folio, parent);
216 out:
217         return;
218 }
219
220 /*
221  * Force the hugetlb cgroup to empty the hugetlb resources by moving them to
222  * the parent cgroup.
223  */
224 static void hugetlb_cgroup_css_offline(struct cgroup_subsys_state *css)
225 {
226         struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(css);
227         struct hstate *h;
228         struct page *page;
229
230         do {
231                 for_each_hstate(h) {
232                         spin_lock_irq(&hugetlb_lock);
233                         list_for_each_entry(page, &h->hugepage_activelist, lru)
234                                 hugetlb_cgroup_move_parent(hstate_index(h), h_cg, page);
235
236                         spin_unlock_irq(&hugetlb_lock);
237                 }
238                 cond_resched();
239         } while (hugetlb_cgroup_have_usage(h_cg));
240 }
241
242 static inline void hugetlb_event(struct hugetlb_cgroup *hugetlb, int idx,
243                                  enum hugetlb_memory_event event)
244 {
245         atomic_long_inc(&hugetlb->events_local[idx][event]);
246         cgroup_file_notify(&hugetlb->events_local_file[idx]);
247
248         do {
249                 atomic_long_inc(&hugetlb->events[idx][event]);
250                 cgroup_file_notify(&hugetlb->events_file[idx]);
251         } while ((hugetlb = parent_hugetlb_cgroup(hugetlb)) &&
252                  !hugetlb_cgroup_is_root(hugetlb));
253 }
254
255 static int __hugetlb_cgroup_charge_cgroup(int idx, unsigned long nr_pages,
256                                           struct hugetlb_cgroup **ptr,
257                                           bool rsvd)
258 {
259         int ret = 0;
260         struct page_counter *counter;
261         struct hugetlb_cgroup *h_cg = NULL;
262
263         if (hugetlb_cgroup_disabled())
264                 goto done;
265         /*
266          * We don't charge any cgroup if the compound page have less
267          * than 3 pages.
268          */
269         if (huge_page_order(&hstates[idx]) < HUGETLB_CGROUP_MIN_ORDER)
270                 goto done;
271 again:
272         rcu_read_lock();
273         h_cg = hugetlb_cgroup_from_task(current);
274         if (!css_tryget(&h_cg->css)) {
275                 rcu_read_unlock();
276                 goto again;
277         }
278         rcu_read_unlock();
279
280         if (!page_counter_try_charge(
281                     __hugetlb_cgroup_counter_from_cgroup(h_cg, idx, rsvd),
282                     nr_pages, &counter)) {
283                 ret = -ENOMEM;
284                 hugetlb_event(h_cg, idx, HUGETLB_MAX);
285                 css_put(&h_cg->css);
286                 goto done;
287         }
288         /* Reservations take a reference to the css because they do not get
289          * reparented.
290          */
291         if (!rsvd)
292                 css_put(&h_cg->css);
293 done:
294         *ptr = h_cg;
295         return ret;
296 }
297
298 int hugetlb_cgroup_charge_cgroup(int idx, unsigned long nr_pages,
299                                  struct hugetlb_cgroup **ptr)
300 {
301         return __hugetlb_cgroup_charge_cgroup(idx, nr_pages, ptr, false);
302 }
303
304 int hugetlb_cgroup_charge_cgroup_rsvd(int idx, unsigned long nr_pages,
305                                       struct hugetlb_cgroup **ptr)
306 {
307         return __hugetlb_cgroup_charge_cgroup(idx, nr_pages, ptr, true);
308 }
309
310 /* Should be called with hugetlb_lock held */
311 static void __hugetlb_cgroup_commit_charge(int idx, unsigned long nr_pages,
312                                            struct hugetlb_cgroup *h_cg,
313                                            struct folio *folio, bool rsvd)
314 {
315         if (hugetlb_cgroup_disabled() || !h_cg)
316                 return;
317
318         __set_hugetlb_cgroup(folio, h_cg, rsvd);
319         if (!rsvd) {
320                 unsigned long usage =
321                         h_cg->nodeinfo[folio_nid(folio)]->usage[idx];
322                 /*
323                  * This write is not atomic due to fetching usage and writing
324                  * to it, but that's fine because we call this with
325                  * hugetlb_lock held anyway.
326                  */
327                 WRITE_ONCE(h_cg->nodeinfo[folio_nid(folio)]->usage[idx],
328                            usage + nr_pages);
329         }
330 }
331
332 void hugetlb_cgroup_commit_charge(int idx, unsigned long nr_pages,
333                                   struct hugetlb_cgroup *h_cg,
334                                   struct folio *folio)
335 {
336         __hugetlb_cgroup_commit_charge(idx, nr_pages, h_cg, folio, false);
337 }
338
339 void hugetlb_cgroup_commit_charge_rsvd(int idx, unsigned long nr_pages,
340                                        struct hugetlb_cgroup *h_cg,
341                                        struct folio *folio)
342 {
343         __hugetlb_cgroup_commit_charge(idx, nr_pages, h_cg, folio, true);
344 }
345
346 /*
347  * Should be called with hugetlb_lock held
348  */
349 static void __hugetlb_cgroup_uncharge_folio(int idx, unsigned long nr_pages,
350                                            struct folio *folio, bool rsvd)
351 {
352         struct hugetlb_cgroup *h_cg;
353
354         if (hugetlb_cgroup_disabled())
355                 return;
356         lockdep_assert_held(&hugetlb_lock);
357         h_cg = __hugetlb_cgroup_from_folio(folio, rsvd);
358         if (unlikely(!h_cg))
359                 return;
360         __set_hugetlb_cgroup(folio, NULL, rsvd);
361
362         page_counter_uncharge(__hugetlb_cgroup_counter_from_cgroup(h_cg, idx,
363                                                                    rsvd),
364                               nr_pages);
365
366         if (rsvd)
367                 css_put(&h_cg->css);
368         else {
369                 unsigned long usage =
370                         h_cg->nodeinfo[folio_nid(folio)]->usage[idx];
371                 /*
372                  * This write is not atomic due to fetching usage and writing
373                  * to it, but that's fine because we call this with
374                  * hugetlb_lock held anyway.
375                  */
376                 WRITE_ONCE(h_cg->nodeinfo[folio_nid(folio)]->usage[idx],
377                            usage - nr_pages);
378         }
379 }
380
381 void hugetlb_cgroup_uncharge_folio(int idx, unsigned long nr_pages,
382                                   struct folio *folio)
383 {
384         __hugetlb_cgroup_uncharge_folio(idx, nr_pages, folio, false);
385 }
386
387 void hugetlb_cgroup_uncharge_folio_rsvd(int idx, unsigned long nr_pages,
388                                        struct folio *folio)
389 {
390         __hugetlb_cgroup_uncharge_folio(idx, nr_pages, folio, true);
391 }
392
393 static void __hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages,
394                                              struct hugetlb_cgroup *h_cg,
395                                              bool rsvd)
396 {
397         if (hugetlb_cgroup_disabled() || !h_cg)
398                 return;
399
400         if (huge_page_order(&hstates[idx]) < HUGETLB_CGROUP_MIN_ORDER)
401                 return;
402
403         page_counter_uncharge(__hugetlb_cgroup_counter_from_cgroup(h_cg, idx,
404                                                                    rsvd),
405                               nr_pages);
406
407         if (rsvd)
408                 css_put(&h_cg->css);
409 }
410
411 void hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages,
412                                     struct hugetlb_cgroup *h_cg)
413 {
414         __hugetlb_cgroup_uncharge_cgroup(idx, nr_pages, h_cg, false);
415 }
416
417 void hugetlb_cgroup_uncharge_cgroup_rsvd(int idx, unsigned long nr_pages,
418                                          struct hugetlb_cgroup *h_cg)
419 {
420         __hugetlb_cgroup_uncharge_cgroup(idx, nr_pages, h_cg, true);
421 }
422
423 void hugetlb_cgroup_uncharge_counter(struct resv_map *resv, unsigned long start,
424                                      unsigned long end)
425 {
426         if (hugetlb_cgroup_disabled() || !resv || !resv->reservation_counter ||
427             !resv->css)
428                 return;
429
430         page_counter_uncharge(resv->reservation_counter,
431                               (end - start) * resv->pages_per_hpage);
432         css_put(resv->css);
433 }
434
435 void hugetlb_cgroup_uncharge_file_region(struct resv_map *resv,
436                                          struct file_region *rg,
437                                          unsigned long nr_pages,
438                                          bool region_del)
439 {
440         if (hugetlb_cgroup_disabled() || !resv || !rg || !nr_pages)
441                 return;
442
443         if (rg->reservation_counter && resv->pages_per_hpage &&
444             !resv->reservation_counter) {
445                 page_counter_uncharge(rg->reservation_counter,
446                                       nr_pages * resv->pages_per_hpage);
447                 /*
448                  * Only do css_put(rg->css) when we delete the entire region
449                  * because one file_region must hold exactly one css reference.
450                  */
451                 if (region_del)
452                         css_put(rg->css);
453         }
454 }
455
456 enum {
457         RES_USAGE,
458         RES_RSVD_USAGE,
459         RES_LIMIT,
460         RES_RSVD_LIMIT,
461         RES_MAX_USAGE,
462         RES_RSVD_MAX_USAGE,
463         RES_FAILCNT,
464         RES_RSVD_FAILCNT,
465 };
466
467 static int hugetlb_cgroup_read_numa_stat(struct seq_file *seq, void *dummy)
468 {
469         int nid;
470         struct cftype *cft = seq_cft(seq);
471         int idx = MEMFILE_IDX(cft->private);
472         bool legacy = MEMFILE_ATTR(cft->private);
473         struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(seq_css(seq));
474         struct cgroup_subsys_state *css;
475         unsigned long usage;
476
477         if (legacy) {
478                 /* Add up usage across all nodes for the non-hierarchical total. */
479                 usage = 0;
480                 for_each_node_state(nid, N_MEMORY)
481                         usage += READ_ONCE(h_cg->nodeinfo[nid]->usage[idx]);
482                 seq_printf(seq, "total=%lu", usage * PAGE_SIZE);
483
484                 /* Simply print the per-node usage for the non-hierarchical total. */
485                 for_each_node_state(nid, N_MEMORY)
486                         seq_printf(seq, " N%d=%lu", nid,
487                                    READ_ONCE(h_cg->nodeinfo[nid]->usage[idx]) *
488                                            PAGE_SIZE);
489                 seq_putc(seq, '\n');
490         }
491
492         /*
493          * The hierarchical total is pretty much the value recorded by the
494          * counter, so use that.
495          */
496         seq_printf(seq, "%stotal=%lu", legacy ? "hierarchical_" : "",
497                    page_counter_read(&h_cg->hugepage[idx]) * PAGE_SIZE);
498
499         /*
500          * For each node, transverse the css tree to obtain the hierarchical
501          * node usage.
502          */
503         for_each_node_state(nid, N_MEMORY) {
504                 usage = 0;
505                 rcu_read_lock();
506                 css_for_each_descendant_pre(css, &h_cg->css) {
507                         usage += READ_ONCE(hugetlb_cgroup_from_css(css)
508                                                    ->nodeinfo[nid]
509                                                    ->usage[idx]);
510                 }
511                 rcu_read_unlock();
512                 seq_printf(seq, " N%d=%lu", nid, usage * PAGE_SIZE);
513         }
514
515         seq_putc(seq, '\n');
516
517         return 0;
518 }
519
520 static u64 hugetlb_cgroup_read_u64(struct cgroup_subsys_state *css,
521                                    struct cftype *cft)
522 {
523         struct page_counter *counter;
524         struct page_counter *rsvd_counter;
525         struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(css);
526
527         counter = &h_cg->hugepage[MEMFILE_IDX(cft->private)];
528         rsvd_counter = &h_cg->rsvd_hugepage[MEMFILE_IDX(cft->private)];
529
530         switch (MEMFILE_ATTR(cft->private)) {
531         case RES_USAGE:
532                 return (u64)page_counter_read(counter) * PAGE_SIZE;
533         case RES_RSVD_USAGE:
534                 return (u64)page_counter_read(rsvd_counter) * PAGE_SIZE;
535         case RES_LIMIT:
536                 return (u64)counter->max * PAGE_SIZE;
537         case RES_RSVD_LIMIT:
538                 return (u64)rsvd_counter->max * PAGE_SIZE;
539         case RES_MAX_USAGE:
540                 return (u64)counter->watermark * PAGE_SIZE;
541         case RES_RSVD_MAX_USAGE:
542                 return (u64)rsvd_counter->watermark * PAGE_SIZE;
543         case RES_FAILCNT:
544                 return counter->failcnt;
545         case RES_RSVD_FAILCNT:
546                 return rsvd_counter->failcnt;
547         default:
548                 BUG();
549         }
550 }
551
552 static int hugetlb_cgroup_read_u64_max(struct seq_file *seq, void *v)
553 {
554         int idx;
555         u64 val;
556         struct cftype *cft = seq_cft(seq);
557         unsigned long limit;
558         struct page_counter *counter;
559         struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(seq_css(seq));
560
561         idx = MEMFILE_IDX(cft->private);
562         counter = &h_cg->hugepage[idx];
563
564         limit = round_down(PAGE_COUNTER_MAX,
565                            pages_per_huge_page(&hstates[idx]));
566
567         switch (MEMFILE_ATTR(cft->private)) {
568         case RES_RSVD_USAGE:
569                 counter = &h_cg->rsvd_hugepage[idx];
570                 fallthrough;
571         case RES_USAGE:
572                 val = (u64)page_counter_read(counter);
573                 seq_printf(seq, "%llu\n", val * PAGE_SIZE);
574                 break;
575         case RES_RSVD_LIMIT:
576                 counter = &h_cg->rsvd_hugepage[idx];
577                 fallthrough;
578         case RES_LIMIT:
579                 val = (u64)counter->max;
580                 if (val == limit)
581                         seq_puts(seq, "max\n");
582                 else
583                         seq_printf(seq, "%llu\n", val * PAGE_SIZE);
584                 break;
585         default:
586                 BUG();
587         }
588
589         return 0;
590 }
591
592 static DEFINE_MUTEX(hugetlb_limit_mutex);
593
594 static ssize_t hugetlb_cgroup_write(struct kernfs_open_file *of,
595                                     char *buf, size_t nbytes, loff_t off,
596                                     const char *max)
597 {
598         int ret, idx;
599         unsigned long nr_pages;
600         struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(of_css(of));
601         bool rsvd = false;
602
603         if (hugetlb_cgroup_is_root(h_cg)) /* Can't set limit on root */
604                 return -EINVAL;
605
606         buf = strstrip(buf);
607         ret = page_counter_memparse(buf, max, &nr_pages);
608         if (ret)
609                 return ret;
610
611         idx = MEMFILE_IDX(of_cft(of)->private);
612         nr_pages = round_down(nr_pages, pages_per_huge_page(&hstates[idx]));
613
614         switch (MEMFILE_ATTR(of_cft(of)->private)) {
615         case RES_RSVD_LIMIT:
616                 rsvd = true;
617                 fallthrough;
618         case RES_LIMIT:
619                 mutex_lock(&hugetlb_limit_mutex);
620                 ret = page_counter_set_max(
621                         __hugetlb_cgroup_counter_from_cgroup(h_cg, idx, rsvd),
622                         nr_pages);
623                 mutex_unlock(&hugetlb_limit_mutex);
624                 break;
625         default:
626                 ret = -EINVAL;
627                 break;
628         }
629         return ret ?: nbytes;
630 }
631
632 static ssize_t hugetlb_cgroup_write_legacy(struct kernfs_open_file *of,
633                                            char *buf, size_t nbytes, loff_t off)
634 {
635         return hugetlb_cgroup_write(of, buf, nbytes, off, "-1");
636 }
637
638 static ssize_t hugetlb_cgroup_write_dfl(struct kernfs_open_file *of,
639                                         char *buf, size_t nbytes, loff_t off)
640 {
641         return hugetlb_cgroup_write(of, buf, nbytes, off, "max");
642 }
643
644 static ssize_t hugetlb_cgroup_reset(struct kernfs_open_file *of,
645                                     char *buf, size_t nbytes, loff_t off)
646 {
647         int ret = 0;
648         struct page_counter *counter, *rsvd_counter;
649         struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(of_css(of));
650
651         counter = &h_cg->hugepage[MEMFILE_IDX(of_cft(of)->private)];
652         rsvd_counter = &h_cg->rsvd_hugepage[MEMFILE_IDX(of_cft(of)->private)];
653
654         switch (MEMFILE_ATTR(of_cft(of)->private)) {
655         case RES_MAX_USAGE:
656                 page_counter_reset_watermark(counter);
657                 break;
658         case RES_RSVD_MAX_USAGE:
659                 page_counter_reset_watermark(rsvd_counter);
660                 break;
661         case RES_FAILCNT:
662                 counter->failcnt = 0;
663                 break;
664         case RES_RSVD_FAILCNT:
665                 rsvd_counter->failcnt = 0;
666                 break;
667         default:
668                 ret = -EINVAL;
669                 break;
670         }
671         return ret ?: nbytes;
672 }
673
674 static char *mem_fmt(char *buf, int size, unsigned long hsize)
675 {
676         if (hsize >= SZ_1G)
677                 snprintf(buf, size, "%luGB", hsize / SZ_1G);
678         else if (hsize >= SZ_1M)
679                 snprintf(buf, size, "%luMB", hsize / SZ_1M);
680         else
681                 snprintf(buf, size, "%luKB", hsize / SZ_1K);
682         return buf;
683 }
684
685 static int __hugetlb_events_show(struct seq_file *seq, bool local)
686 {
687         int idx;
688         long max;
689         struct cftype *cft = seq_cft(seq);
690         struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(seq_css(seq));
691
692         idx = MEMFILE_IDX(cft->private);
693
694         if (local)
695                 max = atomic_long_read(&h_cg->events_local[idx][HUGETLB_MAX]);
696         else
697                 max = atomic_long_read(&h_cg->events[idx][HUGETLB_MAX]);
698
699         seq_printf(seq, "max %lu\n", max);
700
701         return 0;
702 }
703
704 static int hugetlb_events_show(struct seq_file *seq, void *v)
705 {
706         return __hugetlb_events_show(seq, false);
707 }
708
709 static int hugetlb_events_local_show(struct seq_file *seq, void *v)
710 {
711         return __hugetlb_events_show(seq, true);
712 }
713
714 static void __init __hugetlb_cgroup_file_dfl_init(int idx)
715 {
716         char buf[32];
717         struct cftype *cft;
718         struct hstate *h = &hstates[idx];
719
720         /* format the size */
721         mem_fmt(buf, sizeof(buf), huge_page_size(h));
722
723         /* Add the limit file */
724         cft = &h->cgroup_files_dfl[0];
725         snprintf(cft->name, MAX_CFTYPE_NAME, "%s.max", buf);
726         cft->private = MEMFILE_PRIVATE(idx, RES_LIMIT);
727         cft->seq_show = hugetlb_cgroup_read_u64_max;
728         cft->write = hugetlb_cgroup_write_dfl;
729         cft->flags = CFTYPE_NOT_ON_ROOT;
730
731         /* Add the reservation limit file */
732         cft = &h->cgroup_files_dfl[1];
733         snprintf(cft->name, MAX_CFTYPE_NAME, "%s.rsvd.max", buf);
734         cft->private = MEMFILE_PRIVATE(idx, RES_RSVD_LIMIT);
735         cft->seq_show = hugetlb_cgroup_read_u64_max;
736         cft->write = hugetlb_cgroup_write_dfl;
737         cft->flags = CFTYPE_NOT_ON_ROOT;
738
739         /* Add the current usage file */
740         cft = &h->cgroup_files_dfl[2];
741         snprintf(cft->name, MAX_CFTYPE_NAME, "%s.current", buf);
742         cft->private = MEMFILE_PRIVATE(idx, RES_USAGE);
743         cft->seq_show = hugetlb_cgroup_read_u64_max;
744         cft->flags = CFTYPE_NOT_ON_ROOT;
745
746         /* Add the current reservation usage file */
747         cft = &h->cgroup_files_dfl[3];
748         snprintf(cft->name, MAX_CFTYPE_NAME, "%s.rsvd.current", buf);
749         cft->private = MEMFILE_PRIVATE(idx, RES_RSVD_USAGE);
750         cft->seq_show = hugetlb_cgroup_read_u64_max;
751         cft->flags = CFTYPE_NOT_ON_ROOT;
752
753         /* Add the events file */
754         cft = &h->cgroup_files_dfl[4];
755         snprintf(cft->name, MAX_CFTYPE_NAME, "%s.events", buf);
756         cft->private = MEMFILE_PRIVATE(idx, 0);
757         cft->seq_show = hugetlb_events_show;
758         cft->file_offset = offsetof(struct hugetlb_cgroup, events_file[idx]);
759         cft->flags = CFTYPE_NOT_ON_ROOT;
760
761         /* Add the events.local file */
762         cft = &h->cgroup_files_dfl[5];
763         snprintf(cft->name, MAX_CFTYPE_NAME, "%s.events.local", buf);
764         cft->private = MEMFILE_PRIVATE(idx, 0);
765         cft->seq_show = hugetlb_events_local_show;
766         cft->file_offset = offsetof(struct hugetlb_cgroup,
767                                     events_local_file[idx]);
768         cft->flags = CFTYPE_NOT_ON_ROOT;
769
770         /* Add the numa stat file */
771         cft = &h->cgroup_files_dfl[6];
772         snprintf(cft->name, MAX_CFTYPE_NAME, "%s.numa_stat", buf);
773         cft->private = MEMFILE_PRIVATE(idx, 0);
774         cft->seq_show = hugetlb_cgroup_read_numa_stat;
775         cft->flags = CFTYPE_NOT_ON_ROOT;
776
777         /* NULL terminate the last cft */
778         cft = &h->cgroup_files_dfl[7];
779         memset(cft, 0, sizeof(*cft));
780
781         WARN_ON(cgroup_add_dfl_cftypes(&hugetlb_cgrp_subsys,
782                                        h->cgroup_files_dfl));
783 }
784
785 static void __init __hugetlb_cgroup_file_legacy_init(int idx)
786 {
787         char buf[32];
788         struct cftype *cft;
789         struct hstate *h = &hstates[idx];
790
791         /* format the size */
792         mem_fmt(buf, sizeof(buf), huge_page_size(h));
793
794         /* Add the limit file */
795         cft = &h->cgroup_files_legacy[0];
796         snprintf(cft->name, MAX_CFTYPE_NAME, "%s.limit_in_bytes", buf);
797         cft->private = MEMFILE_PRIVATE(idx, RES_LIMIT);
798         cft->read_u64 = hugetlb_cgroup_read_u64;
799         cft->write = hugetlb_cgroup_write_legacy;
800
801         /* Add the reservation limit file */
802         cft = &h->cgroup_files_legacy[1];
803         snprintf(cft->name, MAX_CFTYPE_NAME, "%s.rsvd.limit_in_bytes", buf);
804         cft->private = MEMFILE_PRIVATE(idx, RES_RSVD_LIMIT);
805         cft->read_u64 = hugetlb_cgroup_read_u64;
806         cft->write = hugetlb_cgroup_write_legacy;
807
808         /* Add the usage file */
809         cft = &h->cgroup_files_legacy[2];
810         snprintf(cft->name, MAX_CFTYPE_NAME, "%s.usage_in_bytes", buf);
811         cft->private = MEMFILE_PRIVATE(idx, RES_USAGE);
812         cft->read_u64 = hugetlb_cgroup_read_u64;
813
814         /* Add the reservation usage file */
815         cft = &h->cgroup_files_legacy[3];
816         snprintf(cft->name, MAX_CFTYPE_NAME, "%s.rsvd.usage_in_bytes", buf);
817         cft->private = MEMFILE_PRIVATE(idx, RES_RSVD_USAGE);
818         cft->read_u64 = hugetlb_cgroup_read_u64;
819
820         /* Add the MAX usage file */
821         cft = &h->cgroup_files_legacy[4];
822         snprintf(cft->name, MAX_CFTYPE_NAME, "%s.max_usage_in_bytes", buf);
823         cft->private = MEMFILE_PRIVATE(idx, RES_MAX_USAGE);
824         cft->write = hugetlb_cgroup_reset;
825         cft->read_u64 = hugetlb_cgroup_read_u64;
826
827         /* Add the MAX reservation usage file */
828         cft = &h->cgroup_files_legacy[5];
829         snprintf(cft->name, MAX_CFTYPE_NAME, "%s.rsvd.max_usage_in_bytes", buf);
830         cft->private = MEMFILE_PRIVATE(idx, RES_RSVD_MAX_USAGE);
831         cft->write = hugetlb_cgroup_reset;
832         cft->read_u64 = hugetlb_cgroup_read_u64;
833
834         /* Add the failcntfile */
835         cft = &h->cgroup_files_legacy[6];
836         snprintf(cft->name, MAX_CFTYPE_NAME, "%s.failcnt", buf);
837         cft->private = MEMFILE_PRIVATE(idx, RES_FAILCNT);
838         cft->write = hugetlb_cgroup_reset;
839         cft->read_u64 = hugetlb_cgroup_read_u64;
840
841         /* Add the reservation failcntfile */
842         cft = &h->cgroup_files_legacy[7];
843         snprintf(cft->name, MAX_CFTYPE_NAME, "%s.rsvd.failcnt", buf);
844         cft->private = MEMFILE_PRIVATE(idx, RES_RSVD_FAILCNT);
845         cft->write = hugetlb_cgroup_reset;
846         cft->read_u64 = hugetlb_cgroup_read_u64;
847
848         /* Add the numa stat file */
849         cft = &h->cgroup_files_legacy[8];
850         snprintf(cft->name, MAX_CFTYPE_NAME, "%s.numa_stat", buf);
851         cft->private = MEMFILE_PRIVATE(idx, 1);
852         cft->seq_show = hugetlb_cgroup_read_numa_stat;
853
854         /* NULL terminate the last cft */
855         cft = &h->cgroup_files_legacy[9];
856         memset(cft, 0, sizeof(*cft));
857
858         WARN_ON(cgroup_add_legacy_cftypes(&hugetlb_cgrp_subsys,
859                                           h->cgroup_files_legacy));
860 }
861
862 static void __init __hugetlb_cgroup_file_init(int idx)
863 {
864         __hugetlb_cgroup_file_dfl_init(idx);
865         __hugetlb_cgroup_file_legacy_init(idx);
866 }
867
868 void __init hugetlb_cgroup_file_init(void)
869 {
870         struct hstate *h;
871
872         for_each_hstate(h) {
873                 /*
874                  * Add cgroup control files only if the huge page consists
875                  * of more than two normal pages. This is because we use
876                  * page[2].private for storing cgroup details.
877                  */
878                 if (huge_page_order(h) >= HUGETLB_CGROUP_MIN_ORDER)
879                         __hugetlb_cgroup_file_init(hstate_index(h));
880         }
881 }
882
883 /*
884  * hugetlb_lock will make sure a parallel cgroup rmdir won't happen
885  * when we migrate hugepages
886  */
887 void hugetlb_cgroup_migrate(struct folio *old_folio, struct folio *new_folio)
888 {
889         struct hugetlb_cgroup *h_cg;
890         struct hugetlb_cgroup *h_cg_rsvd;
891         struct hstate *h = folio_hstate(old_folio);
892
893         if (hugetlb_cgroup_disabled())
894                 return;
895
896         spin_lock_irq(&hugetlb_lock);
897         h_cg = hugetlb_cgroup_from_folio(old_folio);
898         h_cg_rsvd = hugetlb_cgroup_from_folio_rsvd(old_folio);
899         set_hugetlb_cgroup(old_folio, NULL);
900         set_hugetlb_cgroup_rsvd(old_folio, NULL);
901
902         /* move the h_cg details to new cgroup */
903         set_hugetlb_cgroup(new_folio, h_cg);
904         set_hugetlb_cgroup_rsvd(new_folio, h_cg_rsvd);
905         list_move(&new_folio->lru, &h->hugepage_activelist);
906         spin_unlock_irq(&hugetlb_lock);
907         return;
908 }
909
910 static struct cftype hugetlb_files[] = {
911         {} /* terminate */
912 };
913
914 struct cgroup_subsys hugetlb_cgrp_subsys = {
915         .css_alloc      = hugetlb_cgroup_css_alloc,
916         .css_offline    = hugetlb_cgroup_css_offline,
917         .css_free       = hugetlb_cgroup_css_free,
918         .dfl_cftypes    = hugetlb_files,
919         .legacy_cftypes = hugetlb_files,
920 };