Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 1 | /* |
| 2 | * padata.c - generic interface to process data streams in parallel |
| 3 | * |
| 4 | * Copyright (C) 2008, 2009 secunet Security Networks AG |
| 5 | * Copyright (C) 2008, 2009 Steffen Klassert <steffen.klassert@secunet.com> |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify it |
| 8 | * under the terms and conditions of the GNU General Public License, |
| 9 | * version 2, as published by the Free Software Foundation. |
| 10 | * |
| 11 | * This program is distributed in the hope it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |
| 14 | * more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU General Public License along with |
| 17 | * this program; if not, write to the Free Software Foundation, Inc., |
| 18 | * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. |
| 19 | */ |
| 20 | |
| 21 | #include <linux/module.h> |
| 22 | #include <linux/cpumask.h> |
| 23 | #include <linux/err.h> |
| 24 | #include <linux/cpu.h> |
| 25 | #include <linux/padata.h> |
| 26 | #include <linux/mutex.h> |
| 27 | #include <linux/sched.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 28 | #include <linux/slab.h> |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 29 | #include <linux/rcupdate.h> |
| 30 | |
| 31 | #define MAX_SEQ_NR INT_MAX - NR_CPUS |
Steffen Klassert | 97e3d94 | 2010-04-29 14:37:32 +0200 | [diff] [blame] | 32 | #define MAX_OBJ_NUM 1000 |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 33 | |
| 34 | static int padata_index_to_cpu(struct parallel_data *pd, int cpu_index) |
| 35 | { |
| 36 | int cpu, target_cpu; |
| 37 | |
| 38 | target_cpu = cpumask_first(pd->cpumask); |
| 39 | for (cpu = 0; cpu < cpu_index; cpu++) |
| 40 | target_cpu = cpumask_next(target_cpu, pd->cpumask); |
| 41 | |
| 42 | return target_cpu; |
| 43 | } |
| 44 | |
| 45 | static int padata_cpu_hash(struct padata_priv *padata) |
| 46 | { |
| 47 | int cpu_index; |
| 48 | struct parallel_data *pd; |
| 49 | |
| 50 | pd = padata->pd; |
| 51 | |
| 52 | /* |
| 53 | * Hash the sequence numbers to the cpus by taking |
| 54 | * seq_nr mod. number of cpus in use. |
| 55 | */ |
| 56 | cpu_index = padata->seq_nr % cpumask_weight(pd->cpumask); |
| 57 | |
| 58 | return padata_index_to_cpu(pd, cpu_index); |
| 59 | } |
| 60 | |
| 61 | static void padata_parallel_worker(struct work_struct *work) |
| 62 | { |
| 63 | struct padata_queue *queue; |
| 64 | struct parallel_data *pd; |
| 65 | struct padata_instance *pinst; |
| 66 | LIST_HEAD(local_list); |
| 67 | |
| 68 | local_bh_disable(); |
| 69 | queue = container_of(work, struct padata_queue, pwork); |
| 70 | pd = queue->pd; |
| 71 | pinst = pd->pinst; |
| 72 | |
| 73 | spin_lock(&queue->parallel.lock); |
| 74 | list_replace_init(&queue->parallel.list, &local_list); |
| 75 | spin_unlock(&queue->parallel.lock); |
| 76 | |
| 77 | while (!list_empty(&local_list)) { |
| 78 | struct padata_priv *padata; |
| 79 | |
| 80 | padata = list_entry(local_list.next, |
| 81 | struct padata_priv, list); |
| 82 | |
| 83 | list_del_init(&padata->list); |
| 84 | |
| 85 | padata->parallel(padata); |
| 86 | } |
| 87 | |
| 88 | local_bh_enable(); |
| 89 | } |
| 90 | |
Steffen Klassert | 0198ffd | 2010-05-19 13:44:27 +1000 | [diff] [blame] | 91 | /** |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 92 | * padata_do_parallel - padata parallelization function |
| 93 | * |
| 94 | * @pinst: padata instance |
| 95 | * @padata: object to be parallelized |
| 96 | * @cb_cpu: cpu the serialization callback function will run on, |
| 97 | * must be in the cpumask of padata. |
| 98 | * |
| 99 | * The parallelization callback function will run with BHs off. |
| 100 | * Note: Every object which is parallelized by padata_do_parallel |
| 101 | * must be seen by padata_do_serial. |
| 102 | */ |
| 103 | int padata_do_parallel(struct padata_instance *pinst, |
| 104 | struct padata_priv *padata, int cb_cpu) |
| 105 | { |
| 106 | int target_cpu, err; |
| 107 | struct padata_queue *queue; |
| 108 | struct parallel_data *pd; |
| 109 | |
| 110 | rcu_read_lock_bh(); |
| 111 | |
| 112 | pd = rcu_dereference(pinst->pd); |
| 113 | |
| 114 | err = 0; |
| 115 | if (!(pinst->flags & PADATA_INIT)) |
| 116 | goto out; |
| 117 | |
| 118 | err = -EBUSY; |
| 119 | if ((pinst->flags & PADATA_RESET)) |
| 120 | goto out; |
| 121 | |
| 122 | if (atomic_read(&pd->refcnt) >= MAX_OBJ_NUM) |
| 123 | goto out; |
| 124 | |
| 125 | err = -EINVAL; |
| 126 | if (!cpumask_test_cpu(cb_cpu, pd->cpumask)) |
| 127 | goto out; |
| 128 | |
| 129 | err = -EINPROGRESS; |
| 130 | atomic_inc(&pd->refcnt); |
| 131 | padata->pd = pd; |
| 132 | padata->cb_cpu = cb_cpu; |
| 133 | |
| 134 | if (unlikely(atomic_read(&pd->seq_nr) == pd->max_seq_nr)) |
| 135 | atomic_set(&pd->seq_nr, -1); |
| 136 | |
| 137 | padata->seq_nr = atomic_inc_return(&pd->seq_nr); |
| 138 | |
| 139 | target_cpu = padata_cpu_hash(padata); |
| 140 | queue = per_cpu_ptr(pd->queue, target_cpu); |
| 141 | |
| 142 | spin_lock(&queue->parallel.lock); |
| 143 | list_add_tail(&padata->list, &queue->parallel.list); |
| 144 | spin_unlock(&queue->parallel.lock); |
| 145 | |
| 146 | queue_work_on(target_cpu, pinst->wq, &queue->pwork); |
| 147 | |
| 148 | out: |
| 149 | rcu_read_unlock_bh(); |
| 150 | |
| 151 | return err; |
| 152 | } |
| 153 | EXPORT_SYMBOL(padata_do_parallel); |
| 154 | |
Steffen Klassert | 0198ffd | 2010-05-19 13:44:27 +1000 | [diff] [blame] | 155 | /* |
| 156 | * padata_get_next - Get the next object that needs serialization. |
| 157 | * |
| 158 | * Return values are: |
| 159 | * |
| 160 | * A pointer to the control struct of the next object that needs |
| 161 | * serialization, if present in one of the percpu reorder queues. |
| 162 | * |
| 163 | * NULL, if all percpu reorder queues are empty. |
| 164 | * |
| 165 | * -EINPROGRESS, if the next object that needs serialization will |
| 166 | * be parallel processed by another cpu and is not yet present in |
| 167 | * the cpu's reorder queue. |
| 168 | * |
| 169 | * -ENODATA, if this cpu has to do the parallel processing for |
| 170 | * the next object. |
| 171 | */ |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 172 | static struct padata_priv *padata_get_next(struct parallel_data *pd) |
| 173 | { |
| 174 | int cpu, num_cpus, empty, calc_seq_nr; |
| 175 | int seq_nr, next_nr, overrun, next_overrun; |
| 176 | struct padata_queue *queue, *next_queue; |
| 177 | struct padata_priv *padata; |
| 178 | struct padata_list *reorder; |
| 179 | |
| 180 | empty = 0; |
| 181 | next_nr = -1; |
| 182 | next_overrun = 0; |
| 183 | next_queue = NULL; |
| 184 | |
| 185 | num_cpus = cpumask_weight(pd->cpumask); |
| 186 | |
| 187 | for_each_cpu(cpu, pd->cpumask) { |
| 188 | queue = per_cpu_ptr(pd->queue, cpu); |
| 189 | reorder = &queue->reorder; |
| 190 | |
| 191 | /* |
| 192 | * Calculate the seq_nr of the object that should be |
Steffen Klassert | 0198ffd | 2010-05-19 13:44:27 +1000 | [diff] [blame] | 193 | * next in this reorder queue. |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 194 | */ |
| 195 | overrun = 0; |
| 196 | calc_seq_nr = (atomic_read(&queue->num_obj) * num_cpus) |
| 197 | + queue->cpu_index; |
| 198 | |
| 199 | if (unlikely(calc_seq_nr > pd->max_seq_nr)) { |
| 200 | calc_seq_nr = calc_seq_nr - pd->max_seq_nr - 1; |
| 201 | overrun = 1; |
| 202 | } |
| 203 | |
| 204 | if (!list_empty(&reorder->list)) { |
| 205 | padata = list_entry(reorder->list.next, |
| 206 | struct padata_priv, list); |
| 207 | |
| 208 | seq_nr = padata->seq_nr; |
| 209 | BUG_ON(calc_seq_nr != seq_nr); |
| 210 | } else { |
| 211 | seq_nr = calc_seq_nr; |
| 212 | empty++; |
| 213 | } |
| 214 | |
| 215 | if (next_nr < 0 || seq_nr < next_nr |
| 216 | || (next_overrun && !overrun)) { |
| 217 | next_nr = seq_nr; |
| 218 | next_overrun = overrun; |
| 219 | next_queue = queue; |
| 220 | } |
| 221 | } |
| 222 | |
| 223 | padata = NULL; |
| 224 | |
| 225 | if (empty == num_cpus) |
| 226 | goto out; |
| 227 | |
| 228 | reorder = &next_queue->reorder; |
| 229 | |
| 230 | if (!list_empty(&reorder->list)) { |
| 231 | padata = list_entry(reorder->list.next, |
| 232 | struct padata_priv, list); |
| 233 | |
| 234 | if (unlikely(next_overrun)) { |
| 235 | for_each_cpu(cpu, pd->cpumask) { |
| 236 | queue = per_cpu_ptr(pd->queue, cpu); |
| 237 | atomic_set(&queue->num_obj, 0); |
| 238 | } |
| 239 | } |
| 240 | |
| 241 | spin_lock(&reorder->lock); |
| 242 | list_del_init(&padata->list); |
| 243 | atomic_dec(&pd->reorder_objects); |
| 244 | spin_unlock(&reorder->lock); |
| 245 | |
| 246 | atomic_inc(&next_queue->num_obj); |
| 247 | |
| 248 | goto out; |
| 249 | } |
| 250 | |
Steffen Klassert | d46a5ac | 2010-05-19 13:43:14 +1000 | [diff] [blame] | 251 | queue = per_cpu_ptr(pd->queue, smp_processor_id()); |
| 252 | if (queue->cpu_index == next_queue->cpu_index) { |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 253 | padata = ERR_PTR(-ENODATA); |
| 254 | goto out; |
| 255 | } |
| 256 | |
| 257 | padata = ERR_PTR(-EINPROGRESS); |
| 258 | out: |
| 259 | return padata; |
| 260 | } |
| 261 | |
| 262 | static void padata_reorder(struct parallel_data *pd) |
| 263 | { |
| 264 | struct padata_priv *padata; |
| 265 | struct padata_queue *queue; |
| 266 | struct padata_instance *pinst = pd->pinst; |
| 267 | |
Steffen Klassert | 0198ffd | 2010-05-19 13:44:27 +1000 | [diff] [blame] | 268 | /* |
| 269 | * We need to ensure that only one cpu can work on dequeueing of |
| 270 | * the reorder queue the time. Calculating in which percpu reorder |
| 271 | * queue the next object will arrive takes some time. A spinlock |
| 272 | * would be highly contended. Also it is not clear in which order |
| 273 | * the objects arrive to the reorder queues. So a cpu could wait to |
| 274 | * get the lock just to notice that there is nothing to do at the |
| 275 | * moment. Therefore we use a trylock and let the holder of the lock |
| 276 | * care for all the objects enqueued during the holdtime of the lock. |
| 277 | */ |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 278 | if (!spin_trylock_bh(&pd->lock)) |
Steffen Klassert | d46a5ac | 2010-05-19 13:43:14 +1000 | [diff] [blame] | 279 | return; |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 280 | |
| 281 | while (1) { |
| 282 | padata = padata_get_next(pd); |
| 283 | |
Steffen Klassert | 0198ffd | 2010-05-19 13:44:27 +1000 | [diff] [blame] | 284 | /* |
| 285 | * All reorder queues are empty, or the next object that needs |
| 286 | * serialization is parallel processed by another cpu and is |
| 287 | * still on it's way to the cpu's reorder queue, nothing to |
| 288 | * do for now. |
| 289 | */ |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 290 | if (!padata || PTR_ERR(padata) == -EINPROGRESS) |
| 291 | break; |
| 292 | |
Steffen Klassert | 0198ffd | 2010-05-19 13:44:27 +1000 | [diff] [blame] | 293 | /* |
| 294 | * This cpu has to do the parallel processing of the next |
| 295 | * object. It's waiting in the cpu's parallelization queue, |
| 296 | * so exit imediately. |
| 297 | */ |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 298 | if (PTR_ERR(padata) == -ENODATA) { |
Steffen Klassert | d46a5ac | 2010-05-19 13:43:14 +1000 | [diff] [blame] | 299 | del_timer(&pd->timer); |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 300 | spin_unlock_bh(&pd->lock); |
Steffen Klassert | d46a5ac | 2010-05-19 13:43:14 +1000 | [diff] [blame] | 301 | return; |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 302 | } |
| 303 | |
| 304 | queue = per_cpu_ptr(pd->queue, padata->cb_cpu); |
| 305 | |
| 306 | spin_lock(&queue->serial.lock); |
| 307 | list_add_tail(&padata->list, &queue->serial.list); |
| 308 | spin_unlock(&queue->serial.lock); |
| 309 | |
| 310 | queue_work_on(padata->cb_cpu, pinst->wq, &queue->swork); |
| 311 | } |
| 312 | |
| 313 | spin_unlock_bh(&pd->lock); |
| 314 | |
Steffen Klassert | 0198ffd | 2010-05-19 13:44:27 +1000 | [diff] [blame] | 315 | /* |
| 316 | * The next object that needs serialization might have arrived to |
| 317 | * the reorder queues in the meantime, we will be called again |
| 318 | * from the timer function if noone else cares for it. |
| 319 | */ |
Steffen Klassert | d46a5ac | 2010-05-19 13:43:14 +1000 | [diff] [blame] | 320 | if (atomic_read(&pd->reorder_objects) |
| 321 | && !(pinst->flags & PADATA_RESET)) |
| 322 | mod_timer(&pd->timer, jiffies + HZ); |
| 323 | else |
| 324 | del_timer(&pd->timer); |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 325 | |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 326 | return; |
| 327 | } |
| 328 | |
Steffen Klassert | d46a5ac | 2010-05-19 13:43:14 +1000 | [diff] [blame] | 329 | static void padata_reorder_timer(unsigned long arg) |
| 330 | { |
| 331 | struct parallel_data *pd = (struct parallel_data *)arg; |
| 332 | |
| 333 | padata_reorder(pd); |
| 334 | } |
| 335 | |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 336 | static void padata_serial_worker(struct work_struct *work) |
| 337 | { |
| 338 | struct padata_queue *queue; |
| 339 | struct parallel_data *pd; |
| 340 | LIST_HEAD(local_list); |
| 341 | |
| 342 | local_bh_disable(); |
| 343 | queue = container_of(work, struct padata_queue, swork); |
| 344 | pd = queue->pd; |
| 345 | |
| 346 | spin_lock(&queue->serial.lock); |
| 347 | list_replace_init(&queue->serial.list, &local_list); |
| 348 | spin_unlock(&queue->serial.lock); |
| 349 | |
| 350 | while (!list_empty(&local_list)) { |
| 351 | struct padata_priv *padata; |
| 352 | |
| 353 | padata = list_entry(local_list.next, |
| 354 | struct padata_priv, list); |
| 355 | |
| 356 | list_del_init(&padata->list); |
| 357 | |
| 358 | padata->serial(padata); |
| 359 | atomic_dec(&pd->refcnt); |
| 360 | } |
| 361 | local_bh_enable(); |
| 362 | } |
| 363 | |
Steffen Klassert | 0198ffd | 2010-05-19 13:44:27 +1000 | [diff] [blame] | 364 | /** |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 365 | * padata_do_serial - padata serialization function |
| 366 | * |
| 367 | * @padata: object to be serialized. |
| 368 | * |
| 369 | * padata_do_serial must be called for every parallelized object. |
| 370 | * The serialization callback function will run with BHs off. |
| 371 | */ |
| 372 | void padata_do_serial(struct padata_priv *padata) |
| 373 | { |
| 374 | int cpu; |
| 375 | struct padata_queue *queue; |
| 376 | struct parallel_data *pd; |
| 377 | |
| 378 | pd = padata->pd; |
| 379 | |
| 380 | cpu = get_cpu(); |
| 381 | queue = per_cpu_ptr(pd->queue, cpu); |
| 382 | |
| 383 | spin_lock(&queue->reorder.lock); |
| 384 | atomic_inc(&pd->reorder_objects); |
| 385 | list_add_tail(&padata->list, &queue->reorder.list); |
| 386 | spin_unlock(&queue->reorder.lock); |
| 387 | |
| 388 | put_cpu(); |
| 389 | |
| 390 | padata_reorder(pd); |
| 391 | } |
| 392 | EXPORT_SYMBOL(padata_do_serial); |
| 393 | |
Steffen Klassert | 0198ffd | 2010-05-19 13:44:27 +1000 | [diff] [blame] | 394 | /* Allocate and initialize the internal cpumask dependend resources. */ |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 395 | static struct parallel_data *padata_alloc_pd(struct padata_instance *pinst, |
| 396 | const struct cpumask *cpumask) |
| 397 | { |
| 398 | int cpu, cpu_index, num_cpus; |
| 399 | struct padata_queue *queue; |
| 400 | struct parallel_data *pd; |
| 401 | |
| 402 | cpu_index = 0; |
| 403 | |
| 404 | pd = kzalloc(sizeof(struct parallel_data), GFP_KERNEL); |
| 405 | if (!pd) |
| 406 | goto err; |
| 407 | |
| 408 | pd->queue = alloc_percpu(struct padata_queue); |
| 409 | if (!pd->queue) |
| 410 | goto err_free_pd; |
| 411 | |
| 412 | if (!alloc_cpumask_var(&pd->cpumask, GFP_KERNEL)) |
| 413 | goto err_free_queue; |
| 414 | |
Steffen Klassert | 7b389b2 | 2010-04-29 14:41:36 +0200 | [diff] [blame] | 415 | cpumask_and(pd->cpumask, cpumask, cpu_active_mask); |
| 416 | |
| 417 | for_each_cpu(cpu, pd->cpumask) { |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 418 | queue = per_cpu_ptr(pd->queue, cpu); |
| 419 | |
| 420 | queue->pd = pd; |
| 421 | |
Steffen Klassert | 7b389b2 | 2010-04-29 14:41:36 +0200 | [diff] [blame] | 422 | queue->cpu_index = cpu_index; |
| 423 | cpu_index++; |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 424 | |
| 425 | INIT_LIST_HEAD(&queue->reorder.list); |
| 426 | INIT_LIST_HEAD(&queue->parallel.list); |
| 427 | INIT_LIST_HEAD(&queue->serial.list); |
| 428 | spin_lock_init(&queue->reorder.lock); |
| 429 | spin_lock_init(&queue->parallel.lock); |
| 430 | spin_lock_init(&queue->serial.lock); |
| 431 | |
| 432 | INIT_WORK(&queue->pwork, padata_parallel_worker); |
| 433 | INIT_WORK(&queue->swork, padata_serial_worker); |
| 434 | atomic_set(&queue->num_obj, 0); |
| 435 | } |
| 436 | |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 437 | num_cpus = cpumask_weight(pd->cpumask); |
| 438 | pd->max_seq_nr = (MAX_SEQ_NR / num_cpus) * num_cpus - 1; |
| 439 | |
Steffen Klassert | d46a5ac | 2010-05-19 13:43:14 +1000 | [diff] [blame] | 440 | setup_timer(&pd->timer, padata_reorder_timer, (unsigned long)pd); |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 441 | atomic_set(&pd->seq_nr, -1); |
| 442 | atomic_set(&pd->reorder_objects, 0); |
| 443 | atomic_set(&pd->refcnt, 0); |
| 444 | pd->pinst = pinst; |
| 445 | spin_lock_init(&pd->lock); |
| 446 | |
| 447 | return pd; |
| 448 | |
| 449 | err_free_queue: |
| 450 | free_percpu(pd->queue); |
| 451 | err_free_pd: |
| 452 | kfree(pd); |
| 453 | err: |
| 454 | return NULL; |
| 455 | } |
| 456 | |
| 457 | static void padata_free_pd(struct parallel_data *pd) |
| 458 | { |
| 459 | free_cpumask_var(pd->cpumask); |
| 460 | free_percpu(pd->queue); |
| 461 | kfree(pd); |
| 462 | } |
| 463 | |
Steffen Klassert | 0198ffd | 2010-05-19 13:44:27 +1000 | [diff] [blame] | 464 | /* Flush all objects out of the padata queues. */ |
Steffen Klassert | 2b73b07 | 2010-05-19 13:43:46 +1000 | [diff] [blame] | 465 | static void padata_flush_queues(struct parallel_data *pd) |
| 466 | { |
| 467 | int cpu; |
| 468 | struct padata_queue *queue; |
| 469 | |
| 470 | for_each_cpu(cpu, pd->cpumask) { |
| 471 | queue = per_cpu_ptr(pd->queue, cpu); |
| 472 | flush_work(&queue->pwork); |
| 473 | } |
| 474 | |
| 475 | del_timer_sync(&pd->timer); |
| 476 | |
| 477 | if (atomic_read(&pd->reorder_objects)) |
| 478 | padata_reorder(pd); |
| 479 | |
| 480 | for_each_cpu(cpu, pd->cpumask) { |
| 481 | queue = per_cpu_ptr(pd->queue, cpu); |
| 482 | flush_work(&queue->swork); |
| 483 | } |
| 484 | |
| 485 | BUG_ON(atomic_read(&pd->refcnt) != 0); |
| 486 | } |
| 487 | |
Steffen Klassert | 0198ffd | 2010-05-19 13:44:27 +1000 | [diff] [blame] | 488 | /* Replace the internal control stucture with a new one. */ |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 489 | static void padata_replace(struct padata_instance *pinst, |
| 490 | struct parallel_data *pd_new) |
| 491 | { |
| 492 | struct parallel_data *pd_old = pinst->pd; |
| 493 | |
| 494 | pinst->flags |= PADATA_RESET; |
| 495 | |
| 496 | rcu_assign_pointer(pinst->pd, pd_new); |
| 497 | |
| 498 | synchronize_rcu(); |
| 499 | |
Steffen Klassert | 2b73b07 | 2010-05-19 13:43:46 +1000 | [diff] [blame] | 500 | padata_flush_queues(pd_old); |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 501 | padata_free_pd(pd_old); |
| 502 | |
| 503 | pinst->flags &= ~PADATA_RESET; |
| 504 | } |
| 505 | |
Steffen Klassert | 0198ffd | 2010-05-19 13:44:27 +1000 | [diff] [blame] | 506 | /** |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 507 | * padata_set_cpumask - set the cpumask that padata should use |
| 508 | * |
| 509 | * @pinst: padata instance |
| 510 | * @cpumask: the cpumask to use |
| 511 | */ |
| 512 | int padata_set_cpumask(struct padata_instance *pinst, |
| 513 | cpumask_var_t cpumask) |
| 514 | { |
| 515 | struct parallel_data *pd; |
| 516 | int err = 0; |
| 517 | |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 518 | mutex_lock(&pinst->lock); |
| 519 | |
Steffen Klassert | 6751fb3 | 2010-04-29 14:42:30 +0200 | [diff] [blame] | 520 | get_online_cpus(); |
| 521 | |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 522 | pd = padata_alloc_pd(pinst, cpumask); |
| 523 | if (!pd) { |
| 524 | err = -ENOMEM; |
| 525 | goto out; |
| 526 | } |
| 527 | |
| 528 | cpumask_copy(pinst->cpumask, cpumask); |
| 529 | |
| 530 | padata_replace(pinst, pd); |
| 531 | |
| 532 | out: |
Steffen Klassert | 6751fb3 | 2010-04-29 14:42:30 +0200 | [diff] [blame] | 533 | put_online_cpus(); |
| 534 | |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 535 | mutex_unlock(&pinst->lock); |
| 536 | |
| 537 | return err; |
| 538 | } |
| 539 | EXPORT_SYMBOL(padata_set_cpumask); |
| 540 | |
| 541 | static int __padata_add_cpu(struct padata_instance *pinst, int cpu) |
| 542 | { |
| 543 | struct parallel_data *pd; |
| 544 | |
| 545 | if (cpumask_test_cpu(cpu, cpu_active_mask)) { |
| 546 | pd = padata_alloc_pd(pinst, pinst->cpumask); |
| 547 | if (!pd) |
| 548 | return -ENOMEM; |
| 549 | |
| 550 | padata_replace(pinst, pd); |
| 551 | } |
| 552 | |
| 553 | return 0; |
| 554 | } |
| 555 | |
Steffen Klassert | 0198ffd | 2010-05-19 13:44:27 +1000 | [diff] [blame] | 556 | /** |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 557 | * padata_add_cpu - add a cpu to the padata cpumask |
| 558 | * |
| 559 | * @pinst: padata instance |
| 560 | * @cpu: cpu to add |
| 561 | */ |
| 562 | int padata_add_cpu(struct padata_instance *pinst, int cpu) |
| 563 | { |
| 564 | int err; |
| 565 | |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 566 | mutex_lock(&pinst->lock); |
| 567 | |
Steffen Klassert | 6751fb3 | 2010-04-29 14:42:30 +0200 | [diff] [blame] | 568 | get_online_cpus(); |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 569 | cpumask_set_cpu(cpu, pinst->cpumask); |
| 570 | err = __padata_add_cpu(pinst, cpu); |
Steffen Klassert | 6751fb3 | 2010-04-29 14:42:30 +0200 | [diff] [blame] | 571 | put_online_cpus(); |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 572 | |
| 573 | mutex_unlock(&pinst->lock); |
| 574 | |
| 575 | return err; |
| 576 | } |
| 577 | EXPORT_SYMBOL(padata_add_cpu); |
| 578 | |
| 579 | static int __padata_remove_cpu(struct padata_instance *pinst, int cpu) |
| 580 | { |
| 581 | struct parallel_data *pd; |
| 582 | |
| 583 | if (cpumask_test_cpu(cpu, cpu_online_mask)) { |
| 584 | pd = padata_alloc_pd(pinst, pinst->cpumask); |
| 585 | if (!pd) |
| 586 | return -ENOMEM; |
| 587 | |
| 588 | padata_replace(pinst, pd); |
| 589 | } |
| 590 | |
| 591 | return 0; |
| 592 | } |
| 593 | |
Steffen Klassert | 0198ffd | 2010-05-19 13:44:27 +1000 | [diff] [blame] | 594 | /** |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 595 | * padata_remove_cpu - remove a cpu from the padata cpumask |
| 596 | * |
| 597 | * @pinst: padata instance |
| 598 | * @cpu: cpu to remove |
| 599 | */ |
| 600 | int padata_remove_cpu(struct padata_instance *pinst, int cpu) |
| 601 | { |
| 602 | int err; |
| 603 | |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 604 | mutex_lock(&pinst->lock); |
| 605 | |
Steffen Klassert | 6751fb3 | 2010-04-29 14:42:30 +0200 | [diff] [blame] | 606 | get_online_cpus(); |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 607 | cpumask_clear_cpu(cpu, pinst->cpumask); |
| 608 | err = __padata_remove_cpu(pinst, cpu); |
Steffen Klassert | 6751fb3 | 2010-04-29 14:42:30 +0200 | [diff] [blame] | 609 | put_online_cpus(); |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 610 | |
| 611 | mutex_unlock(&pinst->lock); |
| 612 | |
| 613 | return err; |
| 614 | } |
| 615 | EXPORT_SYMBOL(padata_remove_cpu); |
| 616 | |
Steffen Klassert | 0198ffd | 2010-05-19 13:44:27 +1000 | [diff] [blame] | 617 | /** |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 618 | * padata_start - start the parallel processing |
| 619 | * |
| 620 | * @pinst: padata instance to start |
| 621 | */ |
| 622 | void padata_start(struct padata_instance *pinst) |
| 623 | { |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 624 | mutex_lock(&pinst->lock); |
| 625 | pinst->flags |= PADATA_INIT; |
| 626 | mutex_unlock(&pinst->lock); |
| 627 | } |
| 628 | EXPORT_SYMBOL(padata_start); |
| 629 | |
Steffen Klassert | 0198ffd | 2010-05-19 13:44:27 +1000 | [diff] [blame] | 630 | /** |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 631 | * padata_stop - stop the parallel processing |
| 632 | * |
| 633 | * @pinst: padata instance to stop |
| 634 | */ |
| 635 | void padata_stop(struct padata_instance *pinst) |
| 636 | { |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 637 | mutex_lock(&pinst->lock); |
| 638 | pinst->flags &= ~PADATA_INIT; |
| 639 | mutex_unlock(&pinst->lock); |
| 640 | } |
| 641 | EXPORT_SYMBOL(padata_stop); |
| 642 | |
Steffen Klassert | e2cb2f1 | 2010-04-29 14:40:10 +0200 | [diff] [blame] | 643 | #ifdef CONFIG_HOTPLUG_CPU |
Henrik Kretzschmar | 975d260 | 2010-03-29 16:15:31 +0800 | [diff] [blame] | 644 | static int padata_cpu_callback(struct notifier_block *nfb, |
| 645 | unsigned long action, void *hcpu) |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 646 | { |
| 647 | int err; |
| 648 | struct padata_instance *pinst; |
| 649 | int cpu = (unsigned long)hcpu; |
| 650 | |
| 651 | pinst = container_of(nfb, struct padata_instance, cpu_notifier); |
| 652 | |
| 653 | switch (action) { |
| 654 | case CPU_ONLINE: |
| 655 | case CPU_ONLINE_FROZEN: |
| 656 | if (!cpumask_test_cpu(cpu, pinst->cpumask)) |
| 657 | break; |
| 658 | mutex_lock(&pinst->lock); |
| 659 | err = __padata_add_cpu(pinst, cpu); |
| 660 | mutex_unlock(&pinst->lock); |
| 661 | if (err) |
Akinobu Mita | 80b5184 | 2010-05-26 14:43:32 -0700 | [diff] [blame] | 662 | return notifier_from_errno(err); |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 663 | break; |
| 664 | |
| 665 | case CPU_DOWN_PREPARE: |
| 666 | case CPU_DOWN_PREPARE_FROZEN: |
| 667 | if (!cpumask_test_cpu(cpu, pinst->cpumask)) |
| 668 | break; |
| 669 | mutex_lock(&pinst->lock); |
| 670 | err = __padata_remove_cpu(pinst, cpu); |
| 671 | mutex_unlock(&pinst->lock); |
| 672 | if (err) |
Akinobu Mita | 80b5184 | 2010-05-26 14:43:32 -0700 | [diff] [blame] | 673 | return notifier_from_errno(err); |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 674 | break; |
| 675 | |
| 676 | case CPU_UP_CANCELED: |
| 677 | case CPU_UP_CANCELED_FROZEN: |
| 678 | if (!cpumask_test_cpu(cpu, pinst->cpumask)) |
| 679 | break; |
| 680 | mutex_lock(&pinst->lock); |
| 681 | __padata_remove_cpu(pinst, cpu); |
| 682 | mutex_unlock(&pinst->lock); |
| 683 | |
| 684 | case CPU_DOWN_FAILED: |
| 685 | case CPU_DOWN_FAILED_FROZEN: |
| 686 | if (!cpumask_test_cpu(cpu, pinst->cpumask)) |
| 687 | break; |
| 688 | mutex_lock(&pinst->lock); |
| 689 | __padata_add_cpu(pinst, cpu); |
| 690 | mutex_unlock(&pinst->lock); |
| 691 | } |
| 692 | |
| 693 | return NOTIFY_OK; |
| 694 | } |
Steffen Klassert | e2cb2f1 | 2010-04-29 14:40:10 +0200 | [diff] [blame] | 695 | #endif |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 696 | |
Steffen Klassert | 0198ffd | 2010-05-19 13:44:27 +1000 | [diff] [blame] | 697 | /** |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 698 | * padata_alloc - allocate and initialize a padata instance |
| 699 | * |
| 700 | * @cpumask: cpumask that padata uses for parallelization |
| 701 | * @wq: workqueue to use for the allocated padata instance |
| 702 | */ |
| 703 | struct padata_instance *padata_alloc(const struct cpumask *cpumask, |
| 704 | struct workqueue_struct *wq) |
| 705 | { |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 706 | struct padata_instance *pinst; |
| 707 | struct parallel_data *pd; |
| 708 | |
| 709 | pinst = kzalloc(sizeof(struct padata_instance), GFP_KERNEL); |
| 710 | if (!pinst) |
| 711 | goto err; |
| 712 | |
Steffen Klassert | 6751fb3 | 2010-04-29 14:42:30 +0200 | [diff] [blame] | 713 | get_online_cpus(); |
| 714 | |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 715 | pd = padata_alloc_pd(pinst, cpumask); |
| 716 | if (!pd) |
| 717 | goto err_free_inst; |
| 718 | |
Steffen Klassert | 7478138 | 2010-03-04 13:30:22 +0800 | [diff] [blame] | 719 | if (!alloc_cpumask_var(&pinst->cpumask, GFP_KERNEL)) |
| 720 | goto err_free_pd; |
| 721 | |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 722 | rcu_assign_pointer(pinst->pd, pd); |
| 723 | |
| 724 | pinst->wq = wq; |
| 725 | |
| 726 | cpumask_copy(pinst->cpumask, cpumask); |
| 727 | |
| 728 | pinst->flags = 0; |
| 729 | |
Steffen Klassert | e2cb2f1 | 2010-04-29 14:40:10 +0200 | [diff] [blame] | 730 | #ifdef CONFIG_HOTPLUG_CPU |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 731 | pinst->cpu_notifier.notifier_call = padata_cpu_callback; |
| 732 | pinst->cpu_notifier.priority = 0; |
Steffen Klassert | e2cb2f1 | 2010-04-29 14:40:10 +0200 | [diff] [blame] | 733 | register_hotcpu_notifier(&pinst->cpu_notifier); |
| 734 | #endif |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 735 | |
Steffen Klassert | 6751fb3 | 2010-04-29 14:42:30 +0200 | [diff] [blame] | 736 | put_online_cpus(); |
| 737 | |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 738 | mutex_init(&pinst->lock); |
| 739 | |
| 740 | return pinst; |
| 741 | |
| 742 | err_free_pd: |
| 743 | padata_free_pd(pd); |
| 744 | err_free_inst: |
| 745 | kfree(pinst); |
Steffen Klassert | 6751fb3 | 2010-04-29 14:42:30 +0200 | [diff] [blame] | 746 | put_online_cpus(); |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 747 | err: |
| 748 | return NULL; |
| 749 | } |
| 750 | EXPORT_SYMBOL(padata_alloc); |
| 751 | |
Steffen Klassert | 0198ffd | 2010-05-19 13:44:27 +1000 | [diff] [blame] | 752 | /** |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 753 | * padata_free - free a padata instance |
| 754 | * |
Steffen Klassert | 0198ffd | 2010-05-19 13:44:27 +1000 | [diff] [blame] | 755 | * @padata_inst: padata instance to free |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 756 | */ |
| 757 | void padata_free(struct padata_instance *pinst) |
| 758 | { |
| 759 | padata_stop(pinst); |
| 760 | |
| 761 | synchronize_rcu(); |
| 762 | |
Steffen Klassert | e2cb2f1 | 2010-04-29 14:40:10 +0200 | [diff] [blame] | 763 | #ifdef CONFIG_HOTPLUG_CPU |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 764 | unregister_hotcpu_notifier(&pinst->cpu_notifier); |
Steffen Klassert | e2cb2f1 | 2010-04-29 14:40:10 +0200 | [diff] [blame] | 765 | #endif |
Steffen Klassert | 3789ae7 | 2010-05-19 13:45:35 +1000 | [diff] [blame] | 766 | get_online_cpus(); |
Steffen Klassert | 2b73b07 | 2010-05-19 13:43:46 +1000 | [diff] [blame] | 767 | padata_flush_queues(pinst->pd); |
Steffen Klassert | 3789ae7 | 2010-05-19 13:45:35 +1000 | [diff] [blame] | 768 | put_online_cpus(); |
| 769 | |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 770 | padata_free_pd(pinst->pd); |
Steffen Klassert | 7478138 | 2010-03-04 13:30:22 +0800 | [diff] [blame] | 771 | free_cpumask_var(pinst->cpumask); |
Steffen Klassert | 16295be | 2010-01-06 19:47:10 +1100 | [diff] [blame] | 772 | kfree(pinst); |
| 773 | } |
| 774 | EXPORT_SYMBOL(padata_free); |