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08b21fbf | 1 | // SPDX-License-Identifier: GPL-2.0 |
16295bec SK |
2 | /* |
3 | * padata.c - generic interface to process data streams in parallel | |
4 | * | |
bfcdcef8 | 5 | * See Documentation/core-api/padata.rst for more information. |
107f8bda | 6 | * |
16295bec SK |
7 | * Copyright (C) 2008, 2009 secunet Security Networks AG |
8 | * Copyright (C) 2008, 2009 Steffen Klassert <steffen.klassert@secunet.com> | |
9 | * | |
004ed426 DJ |
10 | * Copyright (c) 2020 Oracle and/or its affiliates. |
11 | * Author: Daniel Jordan <daniel.m.jordan@oracle.com> | |
16295bec SK |
12 | */ |
13 | ||
004ed426 | 14 | #include <linux/completion.h> |
9984de1a | 15 | #include <linux/export.h> |
16295bec SK |
16 | #include <linux/cpumask.h> |
17 | #include <linux/err.h> | |
18 | #include <linux/cpu.h> | |
19 | #include <linux/padata.h> | |
20 | #include <linux/mutex.h> | |
21 | #include <linux/sched.h> | |
5a0e3ad6 | 22 | #include <linux/slab.h> |
5e017dc3 | 23 | #include <linux/sysfs.h> |
16295bec SK |
24 | #include <linux/rcupdate.h> |
25 | ||
004ed426 DJ |
26 | #define PADATA_WORK_ONSTACK 1 /* Work's memory is on stack */ |
27 | ||
4611ce22 DJ |
28 | struct padata_work { |
29 | struct work_struct pw_work; | |
30 | struct list_head pw_list; /* padata_free_works linkage */ | |
31 | void *pw_data; | |
32 | }; | |
33 | ||
34 | static DEFINE_SPINLOCK(padata_works_lock); | |
35 | static struct padata_work *padata_works; | |
36 | static LIST_HEAD(padata_free_works); | |
16295bec | 37 | |
004ed426 DJ |
38 | struct padata_mt_job_state { |
39 | spinlock_t lock; | |
40 | struct completion completion; | |
41 | struct padata_mt_job *job; | |
42 | int nworks; | |
43 | int nworks_fini; | |
44 | unsigned long chunk_size; | |
45 | }; | |
46 | ||
07928d9b | 47 | static void padata_free_pd(struct parallel_data *pd); |
004ed426 | 48 | static void __init padata_mt_helper(struct work_struct *work); |
07928d9b | 49 | |
16295bec SK |
50 | static int padata_index_to_cpu(struct parallel_data *pd, int cpu_index) |
51 | { | |
52 | int cpu, target_cpu; | |
53 | ||
e15bacbe | 54 | target_cpu = cpumask_first(pd->cpumask.pcpu); |
16295bec | 55 | for (cpu = 0; cpu < cpu_index; cpu++) |
e15bacbe | 56 | target_cpu = cpumask_next(target_cpu, pd->cpumask.pcpu); |
16295bec SK |
57 | |
58 | return target_cpu; | |
59 | } | |
60 | ||
bfde23ce | 61 | static int padata_cpu_hash(struct parallel_data *pd, unsigned int seq_nr) |
16295bec | 62 | { |
16295bec SK |
63 | /* |
64 | * Hash the sequence numbers to the cpus by taking | |
65 | * seq_nr mod. number of cpus in use. | |
66 | */ | |
bfde23ce | 67 | int cpu_index = seq_nr % cpumask_weight(pd->cpumask.pcpu); |
16295bec SK |
68 | |
69 | return padata_index_to_cpu(pd, cpu_index); | |
70 | } | |
71 | ||
4611ce22 | 72 | static struct padata_work *padata_work_alloc(void) |
16295bec | 73 | { |
4611ce22 | 74 | struct padata_work *pw; |
16295bec | 75 | |
4611ce22 | 76 | lockdep_assert_held(&padata_works_lock); |
16295bec | 77 | |
4611ce22 DJ |
78 | if (list_empty(&padata_free_works)) |
79 | return NULL; /* No more work items allowed to be queued. */ | |
16295bec | 80 | |
4611ce22 DJ |
81 | pw = list_first_entry(&padata_free_works, struct padata_work, pw_list); |
82 | list_del(&pw->pw_list); | |
83 | return pw; | |
84 | } | |
16295bec | 85 | |
0d24f1b7 NC |
86 | /* |
87 | * This function is marked __ref because this function may be optimized in such | |
88 | * a way that it directly refers to work_fn's address, which causes modpost to | |
89 | * complain when work_fn is marked __init. This scenario was observed with clang | |
90 | * LTO, where padata_work_init() was optimized to refer directly to | |
91 | * padata_mt_helper() because the calls to padata_work_init() with other work_fn | |
92 | * values were eliminated or inlined. | |
93 | */ | |
94 | static void __ref padata_work_init(struct padata_work *pw, work_func_t work_fn, | |
95 | void *data, int flags) | |
4611ce22 | 96 | { |
004ed426 DJ |
97 | if (flags & PADATA_WORK_ONSTACK) |
98 | INIT_WORK_ONSTACK(&pw->pw_work, work_fn); | |
99 | else | |
100 | INIT_WORK(&pw->pw_work, work_fn); | |
4611ce22 DJ |
101 | pw->pw_data = data; |
102 | } | |
16295bec | 103 | |
004ed426 DJ |
104 | static int __init padata_work_alloc_mt(int nworks, void *data, |
105 | struct list_head *head) | |
106 | { | |
107 | int i; | |
108 | ||
58329c43 | 109 | spin_lock_bh(&padata_works_lock); |
004ed426 DJ |
110 | /* Start at 1 because the current task participates in the job. */ |
111 | for (i = 1; i < nworks; ++i) { | |
112 | struct padata_work *pw = padata_work_alloc(); | |
113 | ||
114 | if (!pw) | |
115 | break; | |
116 | padata_work_init(pw, padata_mt_helper, data, 0); | |
117 | list_add(&pw->pw_list, head); | |
118 | } | |
58329c43 | 119 | spin_unlock_bh(&padata_works_lock); |
004ed426 DJ |
120 | |
121 | return i; | |
122 | } | |
123 | ||
4611ce22 DJ |
124 | static void padata_work_free(struct padata_work *pw) |
125 | { | |
126 | lockdep_assert_held(&padata_works_lock); | |
127 | list_add(&pw->pw_list, &padata_free_works); | |
128 | } | |
16295bec | 129 | |
004ed426 DJ |
130 | static void __init padata_works_free(struct list_head *works) |
131 | { | |
132 | struct padata_work *cur, *next; | |
133 | ||
134 | if (list_empty(works)) | |
135 | return; | |
136 | ||
58329c43 | 137 | spin_lock_bh(&padata_works_lock); |
004ed426 DJ |
138 | list_for_each_entry_safe(cur, next, works, pw_list) { |
139 | list_del(&cur->pw_list); | |
140 | padata_work_free(cur); | |
141 | } | |
58329c43 | 142 | spin_unlock_bh(&padata_works_lock); |
004ed426 DJ |
143 | } |
144 | ||
4611ce22 DJ |
145 | static void padata_parallel_worker(struct work_struct *parallel_work) |
146 | { | |
147 | struct padata_work *pw = container_of(parallel_work, struct padata_work, | |
148 | pw_work); | |
149 | struct padata_priv *padata = pw->pw_data; | |
16295bec | 150 | |
4611ce22 DJ |
151 | local_bh_disable(); |
152 | padata->parallel(padata); | |
153 | spin_lock(&padata_works_lock); | |
154 | padata_work_free(pw); | |
155 | spin_unlock(&padata_works_lock); | |
16295bec SK |
156 | local_bh_enable(); |
157 | } | |
158 | ||
0198ffd1 | 159 | /** |
16295bec SK |
160 | * padata_do_parallel - padata parallelization function |
161 | * | |
bbefa1dd | 162 | * @ps: padatashell |
16295bec | 163 | * @padata: object to be parallelized |
e6ce0e08 DJ |
164 | * @cb_cpu: pointer to the CPU that the serialization callback function should |
165 | * run on. If it's not in the serial cpumask of @pinst | |
166 | * (i.e. cpumask.cbcpu), this function selects a fallback CPU and if | |
167 | * none found, returns -EINVAL. | |
16295bec SK |
168 | * |
169 | * The parallelization callback function will run with BHs off. | |
170 | * Note: Every object which is parallelized by padata_do_parallel | |
171 | * must be seen by padata_do_serial. | |
bfcdcef8 DJ |
172 | * |
173 | * Return: 0 on success or else negative error code. | |
16295bec | 174 | */ |
bbefa1dd | 175 | int padata_do_parallel(struct padata_shell *ps, |
e6ce0e08 | 176 | struct padata_priv *padata, int *cb_cpu) |
16295bec | 177 | { |
bbefa1dd | 178 | struct padata_instance *pinst = ps->pinst; |
4611ce22 | 179 | int i, cpu, cpu_index, err; |
16295bec | 180 | struct parallel_data *pd; |
4611ce22 | 181 | struct padata_work *pw; |
16295bec SK |
182 | |
183 | rcu_read_lock_bh(); | |
184 | ||
bbefa1dd | 185 | pd = rcu_dereference_bh(ps->pd); |
16295bec | 186 | |
83f619f3 | 187 | err = -EINVAL; |
7424713b | 188 | if (!(pinst->flags & PADATA_INIT) || pinst->flags & PADATA_INVALID) |
16295bec SK |
189 | goto out; |
190 | ||
e6ce0e08 | 191 | if (!cpumask_test_cpu(*cb_cpu, pd->cpumask.cbcpu)) { |
1c4cafd1 | 192 | if (cpumask_empty(pd->cpumask.cbcpu)) |
e6ce0e08 DJ |
193 | goto out; |
194 | ||
195 | /* Select an alternate fallback CPU and notify the caller. */ | |
196 | cpu_index = *cb_cpu % cpumask_weight(pd->cpumask.cbcpu); | |
197 | ||
198 | cpu = cpumask_first(pd->cpumask.cbcpu); | |
199 | for (i = 0; i < cpu_index; i++) | |
200 | cpu = cpumask_next(cpu, pd->cpumask.cbcpu); | |
201 | ||
202 | *cb_cpu = cpu; | |
203 | } | |
16295bec | 204 | |
8f4f68e7 | 205 | err = -EBUSY; |
16295bec SK |
206 | if ((pinst->flags & PADATA_RESET)) |
207 | goto out; | |
208 | ||
d5ee8e75 | 209 | refcount_inc(&pd->refcnt); |
16295bec | 210 | padata->pd = pd; |
e6ce0e08 | 211 | padata->cb_cpu = *cb_cpu; |
16295bec | 212 | |
4611ce22 DJ |
213 | spin_lock(&padata_works_lock); |
214 | padata->seq_nr = ++pd->seq_nr; | |
215 | pw = padata_work_alloc(); | |
216 | spin_unlock(&padata_works_lock); | |
1b0df11f | 217 | |
34c3a47d DJ |
218 | if (!pw) { |
219 | /* Maximum works limit exceeded, run in the current task. */ | |
220 | padata->parallel(padata); | |
221 | } | |
222 | ||
1b0df11f DJ |
223 | rcu_read_unlock_bh(); |
224 | ||
4611ce22 | 225 | if (pw) { |
004ed426 | 226 | padata_work_init(pw, padata_parallel_worker, padata, 0); |
4611ce22 | 227 | queue_work(pinst->parallel_wq, &pw->pw_work); |
4611ce22 | 228 | } |
16295bec | 229 | |
4611ce22 | 230 | return 0; |
16295bec SK |
231 | out: |
232 | rcu_read_unlock_bh(); | |
233 | ||
234 | return err; | |
235 | } | |
236 | EXPORT_SYMBOL(padata_do_parallel); | |
237 | ||
0198ffd1 | 238 | /* |
bfde23ce | 239 | * padata_find_next - Find the next object that needs serialization. |
0198ffd1 | 240 | * |
bfcdcef8 DJ |
241 | * Return: |
242 | * * A pointer to the control struct of the next object that needs | |
243 | * serialization, if present in one of the percpu reorder queues. | |
244 | * * NULL, if the next object that needs serialization will | |
245 | * be parallel processed by another cpu and is not yet present in | |
246 | * the cpu's reorder queue. | |
0198ffd1 | 247 | */ |
bfde23ce DJ |
248 | static struct padata_priv *padata_find_next(struct parallel_data *pd, |
249 | bool remove_object) | |
16295bec | 250 | { |
16295bec SK |
251 | struct padata_priv *padata; |
252 | struct padata_list *reorder; | |
6fc4dbcf | 253 | int cpu = pd->cpu; |
16295bec | 254 | |
f601c725 | 255 | reorder = per_cpu_ptr(pd->reorder_list, cpu); |
16295bec | 256 | |
de5540d0 | 257 | spin_lock(&reorder->lock); |
bfde23ce DJ |
258 | if (list_empty(&reorder->list)) { |
259 | spin_unlock(&reorder->lock); | |
260 | return NULL; | |
261 | } | |
16295bec | 262 | |
bfde23ce | 263 | padata = list_entry(reorder->list.next, struct padata_priv, list); |
16295bec | 264 | |
bfde23ce DJ |
265 | /* |
266 | * Checks the rare case where two or more parallel jobs have hashed to | |
267 | * the same CPU and one of the later ones finishes first. | |
268 | */ | |
269 | if (padata->seq_nr != pd->processed) { | |
de5540d0 | 270 | spin_unlock(&reorder->lock); |
bfde23ce | 271 | return NULL; |
16295bec SK |
272 | } |
273 | ||
bfde23ce DJ |
274 | if (remove_object) { |
275 | list_del_init(&padata->list); | |
bfde23ce DJ |
276 | ++pd->processed; |
277 | pd->cpu = cpumask_next_wrap(cpu, pd->cpumask.pcpu, -1, false); | |
16295bec SK |
278 | } |
279 | ||
bfde23ce | 280 | spin_unlock(&reorder->lock); |
16295bec SK |
281 | return padata; |
282 | } | |
283 | ||
284 | static void padata_reorder(struct parallel_data *pd) | |
285 | { | |
bbefa1dd | 286 | struct padata_instance *pinst = pd->ps->pinst; |
3047817b | 287 | int cb_cpu; |
16295bec | 288 | struct padata_priv *padata; |
e15bacbe | 289 | struct padata_serial_queue *squeue; |
f601c725 | 290 | struct padata_list *reorder; |
16295bec | 291 | |
0198ffd1 SK |
292 | /* |
293 | * We need to ensure that only one cpu can work on dequeueing of | |
294 | * the reorder queue the time. Calculating in which percpu reorder | |
295 | * queue the next object will arrive takes some time. A spinlock | |
296 | * would be highly contended. Also it is not clear in which order | |
297 | * the objects arrive to the reorder queues. So a cpu could wait to | |
298 | * get the lock just to notice that there is nothing to do at the | |
299 | * moment. Therefore we use a trylock and let the holder of the lock | |
300 | * care for all the objects enqueued during the holdtime of the lock. | |
301 | */ | |
16295bec | 302 | if (!spin_trylock_bh(&pd->lock)) |
d46a5ac7 | 303 | return; |
16295bec SK |
304 | |
305 | while (1) { | |
bfde23ce | 306 | padata = padata_find_next(pd, true); |
16295bec | 307 | |
0198ffd1 | 308 | /* |
69b34844 JD |
309 | * If the next object that needs serialization is parallel |
310 | * processed by another cpu and is still on it's way to the | |
311 | * cpu's reorder queue, nothing to do for now. | |
0198ffd1 | 312 | */ |
bfde23ce | 313 | if (!padata) |
16295bec SK |
314 | break; |
315 | ||
3047817b SK |
316 | cb_cpu = padata->cb_cpu; |
317 | squeue = per_cpu_ptr(pd->squeue, cb_cpu); | |
16295bec | 318 | |
e15bacbe DK |
319 | spin_lock(&squeue->serial.lock); |
320 | list_add_tail(&padata->list, &squeue->serial.list); | |
321 | spin_unlock(&squeue->serial.lock); | |
16295bec | 322 | |
45d153c0 | 323 | queue_work_on(cb_cpu, pinst->serial_wq, &squeue->work); |
16295bec SK |
324 | } |
325 | ||
326 | spin_unlock_bh(&pd->lock); | |
327 | ||
0198ffd1 SK |
328 | /* |
329 | * The next object that needs serialization might have arrived to | |
6fc4dbcf | 330 | * the reorder queues in the meantime. |
cf144f81 | 331 | * |
6fc4dbcf HX |
332 | * Ensure reorder queue is read after pd->lock is dropped so we see |
333 | * new objects from another task in padata_do_serial. Pairs with | |
e04ec0de | 334 | * smp_mb in padata_do_serial. |
0198ffd1 | 335 | */ |
cf144f81 | 336 | smp_mb(); |
16295bec | 337 | |
f601c725 DJ |
338 | reorder = per_cpu_ptr(pd->reorder_list, pd->cpu); |
339 | if (!list_empty(&reorder->list) && padata_find_next(pd, false)) | |
45d153c0 | 340 | queue_work(pinst->serial_wq, &pd->reorder_work); |
16295bec SK |
341 | } |
342 | ||
cf5868c8 MK |
343 | static void invoke_padata_reorder(struct work_struct *work) |
344 | { | |
cf5868c8 MK |
345 | struct parallel_data *pd; |
346 | ||
347 | local_bh_disable(); | |
6fc4dbcf | 348 | pd = container_of(work, struct parallel_data, reorder_work); |
cf5868c8 MK |
349 | padata_reorder(pd); |
350 | local_bh_enable(); | |
351 | } | |
352 | ||
e15bacbe | 353 | static void padata_serial_worker(struct work_struct *serial_work) |
16295bec | 354 | { |
e15bacbe | 355 | struct padata_serial_queue *squeue; |
16295bec SK |
356 | struct parallel_data *pd; |
357 | LIST_HEAD(local_list); | |
07928d9b | 358 | int cnt; |
16295bec SK |
359 | |
360 | local_bh_disable(); | |
e15bacbe DK |
361 | squeue = container_of(serial_work, struct padata_serial_queue, work); |
362 | pd = squeue->pd; | |
16295bec | 363 | |
e15bacbe DK |
364 | spin_lock(&squeue->serial.lock); |
365 | list_replace_init(&squeue->serial.list, &local_list); | |
366 | spin_unlock(&squeue->serial.lock); | |
16295bec | 367 | |
07928d9b HX |
368 | cnt = 0; |
369 | ||
16295bec SK |
370 | while (!list_empty(&local_list)) { |
371 | struct padata_priv *padata; | |
372 | ||
373 | padata = list_entry(local_list.next, | |
374 | struct padata_priv, list); | |
375 | ||
376 | list_del_init(&padata->list); | |
377 | ||
378 | padata->serial(padata); | |
07928d9b | 379 | cnt++; |
16295bec SK |
380 | } |
381 | local_bh_enable(); | |
07928d9b | 382 | |
d5ee8e75 | 383 | if (refcount_sub_and_test(cnt, &pd->refcnt)) |
07928d9b | 384 | padata_free_pd(pd); |
16295bec SK |
385 | } |
386 | ||
0198ffd1 | 387 | /** |
16295bec SK |
388 | * padata_do_serial - padata serialization function |
389 | * | |
390 | * @padata: object to be serialized. | |
391 | * | |
392 | * padata_do_serial must be called for every parallelized object. | |
393 | * The serialization callback function will run with BHs off. | |
394 | */ | |
395 | void padata_do_serial(struct padata_priv *padata) | |
396 | { | |
065cf577 | 397 | struct parallel_data *pd = padata->pd; |
4611ce22 | 398 | int hashed_cpu = padata_cpu_hash(pd, padata->seq_nr); |
f601c725 | 399 | struct padata_list *reorder = per_cpu_ptr(pd->reorder_list, hashed_cpu); |
bfde23ce | 400 | struct padata_priv *cur; |
57ddfecc | 401 | struct list_head *pos; |
16295bec | 402 | |
f601c725 | 403 | spin_lock(&reorder->lock); |
bfde23ce | 404 | /* Sort in ascending order of sequence number. */ |
57ddfecc DJ |
405 | list_for_each_prev(pos, &reorder->list) { |
406 | cur = list_entry(pos, struct padata_priv, list); | |
9a22b281 VN |
407 | /* Compare by difference to consider integer wrap around */ |
408 | if ((signed int)(cur->seq_nr - padata->seq_nr) < 0) | |
bfde23ce | 409 | break; |
57ddfecc DJ |
410 | } |
411 | list_add(&padata->list, pos); | |
f601c725 | 412 | spin_unlock(&reorder->lock); |
16295bec | 413 | |
cf144f81 | 414 | /* |
6fc4dbcf | 415 | * Ensure the addition to the reorder list is ordered correctly |
cf144f81 DJ |
416 | * with the trylock of pd->lock in padata_reorder. Pairs with smp_mb |
417 | * in padata_reorder. | |
418 | */ | |
e04ec0de | 419 | smp_mb(); |
cf144f81 | 420 | |
6fc4dbcf | 421 | padata_reorder(pd); |
16295bec SK |
422 | } |
423 | EXPORT_SYMBOL(padata_do_serial); | |
424 | ||
bbefa1dd | 425 | static int padata_setup_cpumasks(struct padata_instance *pinst) |
16295bec | 426 | { |
bfde23ce | 427 | struct workqueue_attrs *attrs; |
bbefa1dd HX |
428 | int err; |
429 | ||
430 | attrs = alloc_workqueue_attrs(); | |
431 | if (!attrs) | |
432 | return -ENOMEM; | |
433 | ||
434 | /* Restrict parallel_wq workers to pd->cpumask.pcpu. */ | |
435 | cpumask_copy(attrs->cpumask, pinst->cpumask.pcpu); | |
436 | err = apply_workqueue_attrs(pinst->parallel_wq, attrs); | |
437 | free_workqueue_attrs(attrs); | |
438 | ||
439 | return err; | |
440 | } | |
441 | ||
004ed426 DJ |
442 | static void __init padata_mt_helper(struct work_struct *w) |
443 | { | |
444 | struct padata_work *pw = container_of(w, struct padata_work, pw_work); | |
445 | struct padata_mt_job_state *ps = pw->pw_data; | |
446 | struct padata_mt_job *job = ps->job; | |
447 | bool done; | |
448 | ||
449 | spin_lock(&ps->lock); | |
450 | ||
451 | while (job->size > 0) { | |
452 | unsigned long start, size, end; | |
453 | ||
454 | start = job->start; | |
455 | /* So end is chunk size aligned if enough work remains. */ | |
456 | size = roundup(start + 1, ps->chunk_size) - start; | |
457 | size = min(size, job->size); | |
458 | end = start + size; | |
459 | ||
460 | job->start = end; | |
461 | job->size -= size; | |
462 | ||
463 | spin_unlock(&ps->lock); | |
464 | job->thread_fn(start, end, job->fn_arg); | |
465 | spin_lock(&ps->lock); | |
466 | } | |
467 | ||
468 | ++ps->nworks_fini; | |
469 | done = (ps->nworks_fini == ps->nworks); | |
470 | spin_unlock(&ps->lock); | |
471 | ||
472 | if (done) | |
473 | complete(&ps->completion); | |
474 | } | |
475 | ||
476 | /** | |
477 | * padata_do_multithreaded - run a multithreaded job | |
478 | * @job: Description of the job. | |
479 | * | |
480 | * See the definition of struct padata_mt_job for more details. | |
481 | */ | |
482 | void __init padata_do_multithreaded(struct padata_mt_job *job) | |
483 | { | |
484 | /* In case threads finish at different times. */ | |
485 | static const unsigned long load_balance_factor = 4; | |
486 | struct padata_work my_work, *pw; | |
487 | struct padata_mt_job_state ps; | |
488 | LIST_HEAD(works); | |
eb522866 GLS |
489 | int nworks, nid; |
490 | static atomic_t last_used_nid __initdata; | |
004ed426 DJ |
491 | |
492 | if (job->size == 0) | |
493 | return; | |
494 | ||
495 | /* Ensure at least one thread when size < min_chunk. */ | |
f84155ca | 496 | nworks = max(job->size / max(job->min_chunk, job->align), 1ul); |
004ed426 DJ |
497 | nworks = min(nworks, job->max_threads); |
498 | ||
499 | if (nworks == 1) { | |
500 | /* Single thread, no coordination needed, cut to the chase. */ | |
501 | job->thread_fn(job->start, job->start + job->size, job->fn_arg); | |
502 | return; | |
503 | } | |
504 | ||
505 | spin_lock_init(&ps.lock); | |
506 | init_completion(&ps.completion); | |
507 | ps.job = job; | |
508 | ps.nworks = padata_work_alloc_mt(nworks, &ps, &works); | |
509 | ps.nworks_fini = 0; | |
510 | ||
511 | /* | |
512 | * Chunk size is the amount of work a helper does per call to the | |
513 | * thread function. Load balance large jobs between threads by | |
514 | * increasing the number of chunks, guarantee at least the minimum | |
515 | * chunk size from the caller, and honor the caller's alignment. | |
24cc57d8 KG |
516 | * Ensure chunk_size is at least 1 to prevent divide-by-0 |
517 | * panic in padata_mt_helper(). | |
004ed426 DJ |
518 | */ |
519 | ps.chunk_size = job->size / (ps.nworks * load_balance_factor); | |
520 | ps.chunk_size = max(ps.chunk_size, job->min_chunk); | |
24cc57d8 | 521 | ps.chunk_size = max(ps.chunk_size, 1ul); |
004ed426 DJ |
522 | ps.chunk_size = roundup(ps.chunk_size, job->align); |
523 | ||
6d45e1c9 WL |
524 | /* |
525 | * chunk_size can be 0 if the caller sets min_chunk to 0. So force it | |
526 | * to at least 1 to prevent divide-by-0 panic in padata_mt_helper().` | |
527 | */ | |
528 | if (!ps.chunk_size) | |
529 | ps.chunk_size = 1U; | |
530 | ||
004ed426 | 531 | list_for_each_entry(pw, &works, pw_list) |
eb522866 GLS |
532 | if (job->numa_aware) { |
533 | int old_node = atomic_read(&last_used_nid); | |
534 | ||
535 | do { | |
536 | nid = next_node_in(old_node, node_states[N_CPU]); | |
537 | } while (!atomic_try_cmpxchg(&last_used_nid, &old_node, nid)); | |
538 | queue_work_node(nid, system_unbound_wq, &pw->pw_work); | |
539 | } else { | |
540 | queue_work(system_unbound_wq, &pw->pw_work); | |
541 | } | |
004ed426 DJ |
542 | |
543 | /* Use the current thread, which saves starting a workqueue worker. */ | |
544 | padata_work_init(&my_work, padata_mt_helper, &ps, PADATA_WORK_ONSTACK); | |
545 | padata_mt_helper(&my_work.pw_work); | |
546 | ||
547 | /* Wait for all the helpers to finish. */ | |
548 | wait_for_completion(&ps.completion); | |
549 | ||
550 | destroy_work_on_stack(&my_work.pw_work); | |
551 | padata_works_free(&works); | |
552 | } | |
553 | ||
e15bacbe DK |
554 | static void __padata_list_init(struct padata_list *pd_list) |
555 | { | |
556 | INIT_LIST_HEAD(&pd_list->list); | |
557 | spin_lock_init(&pd_list->lock); | |
558 | } | |
16295bec | 559 | |
e15bacbe DK |
560 | /* Initialize all percpu queues used by serial workers */ |
561 | static void padata_init_squeues(struct parallel_data *pd) | |
562 | { | |
563 | int cpu; | |
564 | struct padata_serial_queue *squeue; | |
7b389b2c | 565 | |
e15bacbe DK |
566 | for_each_cpu(cpu, pd->cpumask.cbcpu) { |
567 | squeue = per_cpu_ptr(pd->squeue, cpu); | |
568 | squeue->pd = pd; | |
569 | __padata_list_init(&squeue->serial); | |
570 | INIT_WORK(&squeue->work, padata_serial_worker); | |
571 | } | |
572 | } | |
16295bec | 573 | |
f601c725 DJ |
574 | /* Initialize per-CPU reorder lists */ |
575 | static void padata_init_reorder_list(struct parallel_data *pd) | |
e15bacbe | 576 | { |
c51636a3 | 577 | int cpu; |
f601c725 | 578 | struct padata_list *list; |
16295bec | 579 | |
c51636a3 | 580 | for_each_cpu(cpu, pd->cpumask.pcpu) { |
f601c725 DJ |
581 | list = per_cpu_ptr(pd->reorder_list, cpu); |
582 | __padata_list_init(list); | |
16295bec | 583 | } |
e15bacbe | 584 | } |
16295bec | 585 | |
e15bacbe | 586 | /* Allocate and initialize the internal cpumask dependend resources. */ |
bbefa1dd | 587 | static struct parallel_data *padata_alloc_pd(struct padata_shell *ps) |
e15bacbe | 588 | { |
bbefa1dd | 589 | struct padata_instance *pinst = ps->pinst; |
e15bacbe | 590 | struct parallel_data *pd; |
16295bec | 591 | |
e15bacbe DK |
592 | pd = kzalloc(sizeof(struct parallel_data), GFP_KERNEL); |
593 | if (!pd) | |
594 | goto err; | |
16295bec | 595 | |
f601c725 DJ |
596 | pd->reorder_list = alloc_percpu(struct padata_list); |
597 | if (!pd->reorder_list) | |
e15bacbe DK |
598 | goto err_free_pd; |
599 | ||
600 | pd->squeue = alloc_percpu(struct padata_serial_queue); | |
601 | if (!pd->squeue) | |
f601c725 | 602 | goto err_free_reorder_list; |
bfde23ce | 603 | |
bbefa1dd | 604 | pd->ps = ps; |
cec00e6e DJ |
605 | |
606 | if (!alloc_cpumask_var(&pd->cpumask.pcpu, GFP_KERNEL)) | |
e15bacbe | 607 | goto err_free_squeue; |
cec00e6e DJ |
608 | if (!alloc_cpumask_var(&pd->cpumask.cbcpu, GFP_KERNEL)) |
609 | goto err_free_pcpu; | |
610 | ||
d69e037b DJ |
611 | cpumask_and(pd->cpumask.pcpu, pinst->cpumask.pcpu, cpu_online_mask); |
612 | cpumask_and(pd->cpumask.cbcpu, pinst->cpumask.cbcpu, cpu_online_mask); | |
16295bec | 613 | |
f601c725 | 614 | padata_init_reorder_list(pd); |
e15bacbe | 615 | padata_init_squeues(pd); |
4611ce22 | 616 | pd->seq_nr = -1; |
d5ee8e75 | 617 | refcount_set(&pd->refcnt, 1); |
16295bec | 618 | spin_lock_init(&pd->lock); |
ec9c7d19 | 619 | pd->cpu = cpumask_first(pd->cpumask.pcpu); |
6fc4dbcf | 620 | INIT_WORK(&pd->reorder_work, invoke_padata_reorder); |
16295bec SK |
621 | |
622 | return pd; | |
623 | ||
cec00e6e DJ |
624 | err_free_pcpu: |
625 | free_cpumask_var(pd->cpumask.pcpu); | |
e15bacbe DK |
626 | err_free_squeue: |
627 | free_percpu(pd->squeue); | |
f601c725 DJ |
628 | err_free_reorder_list: |
629 | free_percpu(pd->reorder_list); | |
16295bec SK |
630 | err_free_pd: |
631 | kfree(pd); | |
632 | err: | |
633 | return NULL; | |
634 | } | |
635 | ||
636 | static void padata_free_pd(struct parallel_data *pd) | |
637 | { | |
e15bacbe DK |
638 | free_cpumask_var(pd->cpumask.pcpu); |
639 | free_cpumask_var(pd->cpumask.cbcpu); | |
f601c725 | 640 | free_percpu(pd->reorder_list); |
e15bacbe | 641 | free_percpu(pd->squeue); |
16295bec SK |
642 | kfree(pd); |
643 | } | |
644 | ||
4c879170 SK |
645 | static void __padata_start(struct padata_instance *pinst) |
646 | { | |
647 | pinst->flags |= PADATA_INIT; | |
648 | } | |
649 | ||
ee836555 SK |
650 | static void __padata_stop(struct padata_instance *pinst) |
651 | { | |
652 | if (!(pinst->flags & PADATA_INIT)) | |
653 | return; | |
654 | ||
655 | pinst->flags &= ~PADATA_INIT; | |
656 | ||
657 | synchronize_rcu(); | |
ee836555 SK |
658 | } |
659 | ||
25985edc | 660 | /* Replace the internal control structure with a new one. */ |
bbefa1dd | 661 | static int padata_replace_one(struct padata_shell *ps) |
16295bec | 662 | { |
bbefa1dd | 663 | struct parallel_data *pd_new; |
16295bec | 664 | |
bbefa1dd HX |
665 | pd_new = padata_alloc_pd(ps); |
666 | if (!pd_new) | |
667 | return -ENOMEM; | |
16295bec | 668 | |
bbefa1dd HX |
669 | ps->opd = rcu_dereference_protected(ps->pd, 1); |
670 | rcu_assign_pointer(ps->pd, pd_new); | |
16295bec | 671 | |
bbefa1dd HX |
672 | return 0; |
673 | } | |
674 | ||
894c9ef9 | 675 | static int padata_replace(struct padata_instance *pinst) |
bbefa1dd | 676 | { |
bbefa1dd | 677 | struct padata_shell *ps; |
41ccdbfd | 678 | int err = 0; |
bbefa1dd HX |
679 | |
680 | pinst->flags |= PADATA_RESET; | |
16295bec | 681 | |
bbefa1dd HX |
682 | list_for_each_entry(ps, &pinst->pslist, list) { |
683 | err = padata_replace_one(ps); | |
684 | if (err) | |
685 | break; | |
686 | } | |
687 | ||
688 | synchronize_rcu(); | |
689 | ||
690 | list_for_each_entry_continue_reverse(ps, &pinst->pslist, list) | |
d5ee8e75 | 691 | if (refcount_dec_and_test(&ps->opd->refcnt)) |
bbefa1dd | 692 | padata_free_pd(ps->opd); |
16295bec SK |
693 | |
694 | pinst->flags &= ~PADATA_RESET; | |
bbefa1dd HX |
695 | |
696 | return err; | |
16295bec SK |
697 | } |
698 | ||
33e54450 SK |
699 | /* If cpumask contains no active cpu, we mark the instance as invalid. */ |
700 | static bool padata_validate_cpumask(struct padata_instance *pinst, | |
701 | const struct cpumask *cpumask) | |
702 | { | |
13614e0f | 703 | if (!cpumask_intersects(cpumask, cpu_online_mask)) { |
33e54450 SK |
704 | pinst->flags |= PADATA_INVALID; |
705 | return false; | |
706 | } | |
707 | ||
708 | pinst->flags &= ~PADATA_INVALID; | |
709 | return true; | |
710 | } | |
711 | ||
65ff577e SK |
712 | static int __padata_set_cpumasks(struct padata_instance *pinst, |
713 | cpumask_var_t pcpumask, | |
714 | cpumask_var_t cbcpumask) | |
715 | { | |
716 | int valid; | |
bbefa1dd | 717 | int err; |
65ff577e SK |
718 | |
719 | valid = padata_validate_cpumask(pinst, pcpumask); | |
720 | if (!valid) { | |
721 | __padata_stop(pinst); | |
722 | goto out_replace; | |
723 | } | |
724 | ||
725 | valid = padata_validate_cpumask(pinst, cbcpumask); | |
726 | if (!valid) | |
727 | __padata_stop(pinst); | |
728 | ||
729 | out_replace: | |
65ff577e SK |
730 | cpumask_copy(pinst->cpumask.pcpu, pcpumask); |
731 | cpumask_copy(pinst->cpumask.cbcpu, cbcpumask); | |
732 | ||
894c9ef9 | 733 | err = padata_setup_cpumasks(pinst) ?: padata_replace(pinst); |
65ff577e SK |
734 | |
735 | if (valid) | |
736 | __padata_start(pinst); | |
737 | ||
bbefa1dd | 738 | return err; |
65ff577e SK |
739 | } |
740 | ||
e15bacbe | 741 | /** |
bfcdcef8 DJ |
742 | * padata_set_cpumask - Sets specified by @cpumask_type cpumask to the value |
743 | * equivalent to @cpumask. | |
16295bec | 744 | * @pinst: padata instance |
e15bacbe DK |
745 | * @cpumask_type: PADATA_CPU_SERIAL or PADATA_CPU_PARALLEL corresponding |
746 | * to parallel and serial cpumasks respectively. | |
16295bec | 747 | * @cpumask: the cpumask to use |
bfcdcef8 DJ |
748 | * |
749 | * Return: 0 on success or negative error code | |
16295bec | 750 | */ |
e15bacbe DK |
751 | int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type, |
752 | cpumask_var_t cpumask) | |
753 | { | |
754 | struct cpumask *serial_mask, *parallel_mask; | |
65ff577e SK |
755 | int err = -EINVAL; |
756 | ||
80771c82 | 757 | cpus_read_lock(); |
38228e88 | 758 | mutex_lock(&pinst->lock); |
6751fb3c | 759 | |
e15bacbe DK |
760 | switch (cpumask_type) { |
761 | case PADATA_CPU_PARALLEL: | |
762 | serial_mask = pinst->cpumask.cbcpu; | |
763 | parallel_mask = cpumask; | |
764 | break; | |
765 | case PADATA_CPU_SERIAL: | |
766 | parallel_mask = pinst->cpumask.pcpu; | |
767 | serial_mask = cpumask; | |
768 | break; | |
769 | default: | |
65ff577e | 770 | goto out; |
16295bec SK |
771 | } |
772 | ||
65ff577e | 773 | err = __padata_set_cpumasks(pinst, parallel_mask, serial_mask); |
16295bec SK |
774 | |
775 | out: | |
776 | mutex_unlock(&pinst->lock); | |
80771c82 | 777 | cpus_read_unlock(); |
16295bec SK |
778 | |
779 | return err; | |
780 | } | |
781 | EXPORT_SYMBOL(padata_set_cpumask); | |
782 | ||
19d795b6 AB |
783 | #ifdef CONFIG_HOTPLUG_CPU |
784 | ||
16295bec SK |
785 | static int __padata_add_cpu(struct padata_instance *pinst, int cpu) |
786 | { | |
bbefa1dd | 787 | int err = 0; |
16295bec | 788 | |
13614e0f | 789 | if (cpumask_test_cpu(cpu, cpu_online_mask)) { |
894c9ef9 | 790 | err = padata_replace(pinst); |
33e54450 | 791 | |
e15bacbe DK |
792 | if (padata_validate_cpumask(pinst, pinst->cpumask.pcpu) && |
793 | padata_validate_cpumask(pinst, pinst->cpumask.cbcpu)) | |
33e54450 | 794 | __padata_start(pinst); |
16295bec SK |
795 | } |
796 | ||
bbefa1dd | 797 | return err; |
16295bec SK |
798 | } |
799 | ||
16295bec SK |
800 | static int __padata_remove_cpu(struct padata_instance *pinst, int cpu) |
801 | { | |
bbefa1dd | 802 | int err = 0; |
16295bec | 803 | |
894c9ef9 | 804 | if (!cpumask_test_cpu(cpu, cpu_online_mask)) { |
e15bacbe | 805 | if (!padata_validate_cpumask(pinst, pinst->cpumask.pcpu) || |
b89661df | 806 | !padata_validate_cpumask(pinst, pinst->cpumask.cbcpu)) |
33e54450 | 807 | __padata_stop(pinst); |
33e54450 | 808 | |
894c9ef9 | 809 | err = padata_replace(pinst); |
16295bec SK |
810 | } |
811 | ||
bbefa1dd | 812 | return err; |
16295bec SK |
813 | } |
814 | ||
e15bacbe DK |
815 | static inline int pinst_has_cpu(struct padata_instance *pinst, int cpu) |
816 | { | |
817 | return cpumask_test_cpu(cpu, pinst->cpumask.pcpu) || | |
818 | cpumask_test_cpu(cpu, pinst->cpumask.cbcpu); | |
819 | } | |
820 | ||
30e92153 | 821 | static int padata_cpu_online(unsigned int cpu, struct hlist_node *node) |
16295bec | 822 | { |
16295bec | 823 | struct padata_instance *pinst; |
30e92153 | 824 | int ret; |
16295bec | 825 | |
3c2214b6 | 826 | pinst = hlist_entry_safe(node, struct padata_instance, cpu_online_node); |
30e92153 SAS |
827 | if (!pinst_has_cpu(pinst, cpu)) |
828 | return 0; | |
16295bec | 829 | |
30e92153 SAS |
830 | mutex_lock(&pinst->lock); |
831 | ret = __padata_add_cpu(pinst, cpu); | |
832 | mutex_unlock(&pinst->lock); | |
833 | return ret; | |
834 | } | |
16295bec | 835 | |
894c9ef9 | 836 | static int padata_cpu_dead(unsigned int cpu, struct hlist_node *node) |
30e92153 SAS |
837 | { |
838 | struct padata_instance *pinst; | |
839 | int ret; | |
840 | ||
3c2214b6 | 841 | pinst = hlist_entry_safe(node, struct padata_instance, cpu_dead_node); |
30e92153 SAS |
842 | if (!pinst_has_cpu(pinst, cpu)) |
843 | return 0; | |
16295bec | 844 | |
30e92153 SAS |
845 | mutex_lock(&pinst->lock); |
846 | ret = __padata_remove_cpu(pinst, cpu); | |
847 | mutex_unlock(&pinst->lock); | |
848 | return ret; | |
16295bec | 849 | } |
30e92153 SAS |
850 | |
851 | static enum cpuhp_state hp_online; | |
e2cb2f1c | 852 | #endif |
16295bec | 853 | |
5e017dc3 DK |
854 | static void __padata_free(struct padata_instance *pinst) |
855 | { | |
856 | #ifdef CONFIG_HOTPLUG_CPU | |
3c2214b6 DJ |
857 | cpuhp_state_remove_instance_nocalls(CPUHP_PADATA_DEAD, |
858 | &pinst->cpu_dead_node); | |
859 | cpuhp_state_remove_instance_nocalls(hp_online, &pinst->cpu_online_node); | |
5e017dc3 DK |
860 | #endif |
861 | ||
bbefa1dd HX |
862 | WARN_ON(!list_empty(&pinst->pslist)); |
863 | ||
5e017dc3 DK |
864 | free_cpumask_var(pinst->cpumask.pcpu); |
865 | free_cpumask_var(pinst->cpumask.cbcpu); | |
45d153c0 DJ |
866 | destroy_workqueue(pinst->serial_wq); |
867 | destroy_workqueue(pinst->parallel_wq); | |
5e017dc3 DK |
868 | kfree(pinst); |
869 | } | |
870 | ||
871 | #define kobj2pinst(_kobj) \ | |
872 | container_of(_kobj, struct padata_instance, kobj) | |
873 | #define attr2pentry(_attr) \ | |
874 | container_of(_attr, struct padata_sysfs_entry, attr) | |
875 | ||
876 | static void padata_sysfs_release(struct kobject *kobj) | |
877 | { | |
878 | struct padata_instance *pinst = kobj2pinst(kobj); | |
879 | __padata_free(pinst); | |
880 | } | |
881 | ||
882 | struct padata_sysfs_entry { | |
883 | struct attribute attr; | |
884 | ssize_t (*show)(struct padata_instance *, struct attribute *, char *); | |
885 | ssize_t (*store)(struct padata_instance *, struct attribute *, | |
886 | const char *, size_t); | |
887 | }; | |
888 | ||
889 | static ssize_t show_cpumask(struct padata_instance *pinst, | |
890 | struct attribute *attr, char *buf) | |
891 | { | |
892 | struct cpumask *cpumask; | |
893 | ssize_t len; | |
894 | ||
895 | mutex_lock(&pinst->lock); | |
896 | if (!strcmp(attr->name, "serial_cpumask")) | |
897 | cpumask = pinst->cpumask.cbcpu; | |
898 | else | |
899 | cpumask = pinst->cpumask.pcpu; | |
900 | ||
4497da6f TH |
901 | len = snprintf(buf, PAGE_SIZE, "%*pb\n", |
902 | nr_cpu_ids, cpumask_bits(cpumask)); | |
5e017dc3 | 903 | mutex_unlock(&pinst->lock); |
4497da6f | 904 | return len < PAGE_SIZE ? len : -EINVAL; |
5e017dc3 DK |
905 | } |
906 | ||
907 | static ssize_t store_cpumask(struct padata_instance *pinst, | |
908 | struct attribute *attr, | |
909 | const char *buf, size_t count) | |
910 | { | |
911 | cpumask_var_t new_cpumask; | |
912 | ssize_t ret; | |
913 | int mask_type; | |
914 | ||
915 | if (!alloc_cpumask_var(&new_cpumask, GFP_KERNEL)) | |
916 | return -ENOMEM; | |
917 | ||
918 | ret = bitmap_parse(buf, count, cpumask_bits(new_cpumask), | |
919 | nr_cpumask_bits); | |
920 | if (ret < 0) | |
921 | goto out; | |
922 | ||
923 | mask_type = !strcmp(attr->name, "serial_cpumask") ? | |
924 | PADATA_CPU_SERIAL : PADATA_CPU_PARALLEL; | |
925 | ret = padata_set_cpumask(pinst, mask_type, new_cpumask); | |
926 | if (!ret) | |
927 | ret = count; | |
928 | ||
929 | out: | |
930 | free_cpumask_var(new_cpumask); | |
931 | return ret; | |
932 | } | |
933 | ||
934 | #define PADATA_ATTR_RW(_name, _show_name, _store_name) \ | |
935 | static struct padata_sysfs_entry _name##_attr = \ | |
936 | __ATTR(_name, 0644, _show_name, _store_name) | |
937 | #define PADATA_ATTR_RO(_name, _show_name) \ | |
938 | static struct padata_sysfs_entry _name##_attr = \ | |
939 | __ATTR(_name, 0400, _show_name, NULL) | |
940 | ||
941 | PADATA_ATTR_RW(serial_cpumask, show_cpumask, store_cpumask); | |
942 | PADATA_ATTR_RW(parallel_cpumask, show_cpumask, store_cpumask); | |
943 | ||
944 | /* | |
945 | * Padata sysfs provides the following objects: | |
946 | * serial_cpumask [RW] - cpumask for serial workers | |
947 | * parallel_cpumask [RW] - cpumask for parallel workers | |
948 | */ | |
949 | static struct attribute *padata_default_attrs[] = { | |
950 | &serial_cpumask_attr.attr, | |
951 | ¶llel_cpumask_attr.attr, | |
952 | NULL, | |
953 | }; | |
2064fbc7 | 954 | ATTRIBUTE_GROUPS(padata_default); |
5e017dc3 DK |
955 | |
956 | static ssize_t padata_sysfs_show(struct kobject *kobj, | |
957 | struct attribute *attr, char *buf) | |
958 | { | |
959 | struct padata_instance *pinst; | |
960 | struct padata_sysfs_entry *pentry; | |
961 | ssize_t ret = -EIO; | |
962 | ||
963 | pinst = kobj2pinst(kobj); | |
964 | pentry = attr2pentry(attr); | |
965 | if (pentry->show) | |
966 | ret = pentry->show(pinst, attr, buf); | |
967 | ||
968 | return ret; | |
969 | } | |
970 | ||
971 | static ssize_t padata_sysfs_store(struct kobject *kobj, struct attribute *attr, | |
972 | const char *buf, size_t count) | |
973 | { | |
974 | struct padata_instance *pinst; | |
975 | struct padata_sysfs_entry *pentry; | |
976 | ssize_t ret = -EIO; | |
977 | ||
978 | pinst = kobj2pinst(kobj); | |
979 | pentry = attr2pentry(attr); | |
980 | if (pentry->show) | |
981 | ret = pentry->store(pinst, attr, buf, count); | |
982 | ||
983 | return ret; | |
984 | } | |
985 | ||
986 | static const struct sysfs_ops padata_sysfs_ops = { | |
987 | .show = padata_sysfs_show, | |
988 | .store = padata_sysfs_store, | |
989 | }; | |
990 | ||
0bedc992 | 991 | static const struct kobj_type padata_attr_type = { |
5e017dc3 | 992 | .sysfs_ops = &padata_sysfs_ops, |
2064fbc7 | 993 | .default_groups = padata_default_groups, |
5e017dc3 DK |
994 | .release = padata_sysfs_release, |
995 | }; | |
996 | ||
e15bacbe | 997 | /** |
3f257191 | 998 | * padata_alloc - allocate and initialize a padata instance |
b128a304 | 999 | * @name: used to identify the instance |
bfcdcef8 DJ |
1000 | * |
1001 | * Return: new instance on success, NULL on error | |
16295bec | 1002 | */ |
3f257191 | 1003 | struct padata_instance *padata_alloc(const char *name) |
16295bec | 1004 | { |
16295bec | 1005 | struct padata_instance *pinst; |
16295bec SK |
1006 | |
1007 | pinst = kzalloc(sizeof(struct padata_instance), GFP_KERNEL); | |
1008 | if (!pinst) | |
1009 | goto err; | |
1010 | ||
bfde23ce DJ |
1011 | pinst->parallel_wq = alloc_workqueue("%s_parallel", WQ_UNBOUND, 0, |
1012 | name); | |
45d153c0 | 1013 | if (!pinst->parallel_wq) |
16295bec | 1014 | goto err_free_inst; |
b128a304 | 1015 | |
80771c82 | 1016 | cpus_read_lock(); |
cc491d8e | 1017 | |
45d153c0 DJ |
1018 | pinst->serial_wq = alloc_workqueue("%s_serial", WQ_MEM_RECLAIM | |
1019 | WQ_CPU_INTENSIVE, 1, name); | |
1020 | if (!pinst->serial_wq) | |
cc491d8e | 1021 | goto err_put_cpus; |
45d153c0 DJ |
1022 | |
1023 | if (!alloc_cpumask_var(&pinst->cpumask.pcpu, GFP_KERNEL)) | |
1024 | goto err_free_serial_wq; | |
e15bacbe DK |
1025 | if (!alloc_cpumask_var(&pinst->cpumask.cbcpu, GFP_KERNEL)) { |
1026 | free_cpumask_var(pinst->cpumask.pcpu); | |
45d153c0 | 1027 | goto err_free_serial_wq; |
33e54450 | 1028 | } |
16295bec | 1029 | |
bbefa1dd | 1030 | INIT_LIST_HEAD(&pinst->pslist); |
16295bec | 1031 | |
3f257191 DJ |
1032 | cpumask_copy(pinst->cpumask.pcpu, cpu_possible_mask); |
1033 | cpumask_copy(pinst->cpumask.cbcpu, cpu_possible_mask); | |
bbefa1dd HX |
1034 | |
1035 | if (padata_setup_cpumasks(pinst)) | |
d69e037b | 1036 | goto err_free_masks; |
16295bec | 1037 | |
bd25b488 | 1038 | __padata_start(pinst); |
16295bec | 1039 | |
5e017dc3 | 1040 | kobject_init(&pinst->kobj, &padata_attr_type); |
16295bec SK |
1041 | mutex_init(&pinst->lock); |
1042 | ||
b8b4a416 | 1043 | #ifdef CONFIG_HOTPLUG_CPU |
3c2214b6 DJ |
1044 | cpuhp_state_add_instance_nocalls_cpuslocked(hp_online, |
1045 | &pinst->cpu_online_node); | |
894c9ef9 | 1046 | cpuhp_state_add_instance_nocalls_cpuslocked(CPUHP_PADATA_DEAD, |
3c2214b6 | 1047 | &pinst->cpu_dead_node); |
b8b4a416 | 1048 | #endif |
cc491d8e | 1049 | |
80771c82 | 1050 | cpus_read_unlock(); |
cc491d8e | 1051 | |
16295bec SK |
1052 | return pinst; |
1053 | ||
e15bacbe DK |
1054 | err_free_masks: |
1055 | free_cpumask_var(pinst->cpumask.pcpu); | |
1056 | free_cpumask_var(pinst->cpumask.cbcpu); | |
45d153c0 DJ |
1057 | err_free_serial_wq: |
1058 | destroy_workqueue(pinst->serial_wq); | |
cc491d8e | 1059 | err_put_cpus: |
80771c82 | 1060 | cpus_read_unlock(); |
45d153c0 | 1061 | destroy_workqueue(pinst->parallel_wq); |
16295bec SK |
1062 | err_free_inst: |
1063 | kfree(pinst); | |
1064 | err: | |
1065 | return NULL; | |
1066 | } | |
3f257191 | 1067 | EXPORT_SYMBOL(padata_alloc); |
9596695e | 1068 | |
0198ffd1 | 1069 | /** |
16295bec SK |
1070 | * padata_free - free a padata instance |
1071 | * | |
bfcdcef8 | 1072 | * @pinst: padata instance to free |
16295bec SK |
1073 | */ |
1074 | void padata_free(struct padata_instance *pinst) | |
1075 | { | |
5e017dc3 | 1076 | kobject_put(&pinst->kobj); |
16295bec SK |
1077 | } |
1078 | EXPORT_SYMBOL(padata_free); | |
30e92153 | 1079 | |
bbefa1dd HX |
1080 | /** |
1081 | * padata_alloc_shell - Allocate and initialize padata shell. | |
1082 | * | |
1083 | * @pinst: Parent padata_instance object. | |
bfcdcef8 DJ |
1084 | * |
1085 | * Return: new shell on success, NULL on error | |
bbefa1dd HX |
1086 | */ |
1087 | struct padata_shell *padata_alloc_shell(struct padata_instance *pinst) | |
1088 | { | |
1089 | struct parallel_data *pd; | |
1090 | struct padata_shell *ps; | |
1091 | ||
1092 | ps = kzalloc(sizeof(*ps), GFP_KERNEL); | |
1093 | if (!ps) | |
1094 | goto out; | |
1095 | ||
1096 | ps->pinst = pinst; | |
1097 | ||
80771c82 | 1098 | cpus_read_lock(); |
bbefa1dd | 1099 | pd = padata_alloc_pd(ps); |
80771c82 | 1100 | cpus_read_unlock(); |
bbefa1dd HX |
1101 | |
1102 | if (!pd) | |
1103 | goto out_free_ps; | |
1104 | ||
1105 | mutex_lock(&pinst->lock); | |
1106 | RCU_INIT_POINTER(ps->pd, pd); | |
1107 | list_add(&ps->list, &pinst->pslist); | |
1108 | mutex_unlock(&pinst->lock); | |
1109 | ||
1110 | return ps; | |
1111 | ||
1112 | out_free_ps: | |
1113 | kfree(ps); | |
1114 | out: | |
1115 | return NULL; | |
1116 | } | |
1117 | EXPORT_SYMBOL(padata_alloc_shell); | |
1118 | ||
1119 | /** | |
1120 | * padata_free_shell - free a padata shell | |
1121 | * | |
1122 | * @ps: padata shell to free | |
1123 | */ | |
1124 | void padata_free_shell(struct padata_shell *ps) | |
1125 | { | |
7ddc21e3 W |
1126 | struct parallel_data *pd; |
1127 | ||
07b24c7c EB |
1128 | if (!ps) |
1129 | return; | |
bbefa1dd | 1130 | |
07b24c7c | 1131 | mutex_lock(&ps->pinst->lock); |
bbefa1dd | 1132 | list_del(&ps->list); |
7ddc21e3 W |
1133 | pd = rcu_dereference_protected(ps->pd, 1); |
1134 | if (refcount_dec_and_test(&pd->refcnt)) | |
1135 | padata_free_pd(pd); | |
07b24c7c | 1136 | mutex_unlock(&ps->pinst->lock); |
bbefa1dd HX |
1137 | |
1138 | kfree(ps); | |
1139 | } | |
1140 | EXPORT_SYMBOL(padata_free_shell); | |
1141 | ||
f1b192b1 | 1142 | void __init padata_init(void) |
30e92153 | 1143 | { |
4611ce22 | 1144 | unsigned int i, possible_cpus; |
f1b192b1 | 1145 | #ifdef CONFIG_HOTPLUG_CPU |
30e92153 SAS |
1146 | int ret; |
1147 | ||
1148 | ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "padata:online", | |
894c9ef9 | 1149 | padata_cpu_online, NULL); |
30e92153 | 1150 | if (ret < 0) |
f1b192b1 | 1151 | goto err; |
30e92153 | 1152 | hp_online = ret; |
894c9ef9 DJ |
1153 | |
1154 | ret = cpuhp_setup_state_multi(CPUHP_PADATA_DEAD, "padata:dead", | |
1155 | NULL, padata_cpu_dead); | |
4611ce22 DJ |
1156 | if (ret < 0) |
1157 | goto remove_online_state; | |
1158 | #endif | |
1159 | ||
1160 | possible_cpus = num_possible_cpus(); | |
1161 | padata_works = kmalloc_array(possible_cpus, sizeof(struct padata_work), | |
1162 | GFP_KERNEL); | |
1163 | if (!padata_works) | |
1164 | goto remove_dead_state; | |
1165 | ||
1166 | for (i = 0; i < possible_cpus; ++i) | |
1167 | list_add(&padata_works[i].pw_list, &padata_free_works); | |
30e92153 | 1168 | |
f1b192b1 | 1169 | return; |
4611ce22 DJ |
1170 | |
1171 | remove_dead_state: | |
1172 | #ifdef CONFIG_HOTPLUG_CPU | |
1173 | cpuhp_remove_multi_state(CPUHP_PADATA_DEAD); | |
1174 | remove_online_state: | |
1175 | cpuhp_remove_multi_state(hp_online); | |
f1b192b1 | 1176 | err: |
30e92153 | 1177 | #endif |
4611ce22 | 1178 | pr_warn("padata: initialization failed\n"); |
f1b192b1 | 1179 | } |