Commit | Line | Data |
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f2298c04 | 1 | #include <linux/module.h> |
fc1bc354 | 2 | |
f2298c04 JA |
3 | #include <linux/moduleparam.h> |
4 | #include <linux/sched.h> | |
5 | #include <linux/fs.h> | |
6 | #include <linux/blkdev.h> | |
7 | #include <linux/init.h> | |
8 | #include <linux/slab.h> | |
9 | #include <linux/blk-mq.h> | |
10 | #include <linux/hrtimer.h> | |
11 | ||
12 | struct nullb_cmd { | |
13 | struct list_head list; | |
14 | struct llist_node ll_list; | |
15 | struct call_single_data csd; | |
16 | struct request *rq; | |
17 | struct bio *bio; | |
18 | unsigned int tag; | |
19 | struct nullb_queue *nq; | |
20 | }; | |
21 | ||
22 | struct nullb_queue { | |
23 | unsigned long *tag_map; | |
24 | wait_queue_head_t wait; | |
25 | unsigned int queue_depth; | |
26 | ||
27 | struct nullb_cmd *cmds; | |
28 | }; | |
29 | ||
30 | struct nullb { | |
31 | struct list_head list; | |
32 | unsigned int index; | |
33 | struct request_queue *q; | |
34 | struct gendisk *disk; | |
35 | struct hrtimer timer; | |
36 | unsigned int queue_depth; | |
37 | spinlock_t lock; | |
38 | ||
39 | struct nullb_queue *queues; | |
40 | unsigned int nr_queues; | |
41 | }; | |
42 | ||
43 | static LIST_HEAD(nullb_list); | |
44 | static struct mutex lock; | |
45 | static int null_major; | |
46 | static int nullb_indexes; | |
47 | ||
48 | struct completion_queue { | |
49 | struct llist_head list; | |
50 | struct hrtimer timer; | |
51 | }; | |
52 | ||
53 | /* | |
54 | * These are per-cpu for now, they will need to be configured by the | |
55 | * complete_queues parameter and appropriately mapped. | |
56 | */ | |
57 | static DEFINE_PER_CPU(struct completion_queue, completion_queues); | |
58 | ||
59 | enum { | |
60 | NULL_IRQ_NONE = 0, | |
61 | NULL_IRQ_SOFTIRQ = 1, | |
62 | NULL_IRQ_TIMER = 2, | |
ce2c350b | 63 | }; |
f2298c04 | 64 | |
ce2c350b | 65 | enum { |
f2298c04 JA |
66 | NULL_Q_BIO = 0, |
67 | NULL_Q_RQ = 1, | |
68 | NULL_Q_MQ = 2, | |
69 | }; | |
70 | ||
2d263a78 | 71 | static int submit_queues; |
f2298c04 JA |
72 | module_param(submit_queues, int, S_IRUGO); |
73 | MODULE_PARM_DESC(submit_queues, "Number of submission queues"); | |
74 | ||
75 | static int home_node = NUMA_NO_NODE; | |
76 | module_param(home_node, int, S_IRUGO); | |
77 | MODULE_PARM_DESC(home_node, "Home node for the device"); | |
78 | ||
79 | static int queue_mode = NULL_Q_MQ; | |
80 | module_param(queue_mode, int, S_IRUGO); | |
81 | MODULE_PARM_DESC(use_mq, "Use blk-mq interface (0=bio,1=rq,2=multiqueue)"); | |
82 | ||
83 | static int gb = 250; | |
84 | module_param(gb, int, S_IRUGO); | |
85 | MODULE_PARM_DESC(gb, "Size in GB"); | |
86 | ||
87 | static int bs = 512; | |
88 | module_param(bs, int, S_IRUGO); | |
89 | MODULE_PARM_DESC(bs, "Block size (in bytes)"); | |
90 | ||
91 | static int nr_devices = 2; | |
92 | module_param(nr_devices, int, S_IRUGO); | |
93 | MODULE_PARM_DESC(nr_devices, "Number of devices to register"); | |
94 | ||
95 | static int irqmode = NULL_IRQ_SOFTIRQ; | |
96 | module_param(irqmode, int, S_IRUGO); | |
97 | MODULE_PARM_DESC(irqmode, "IRQ completion handler. 0-none, 1-softirq, 2-timer"); | |
98 | ||
99 | static int completion_nsec = 10000; | |
100 | module_param(completion_nsec, int, S_IRUGO); | |
101 | MODULE_PARM_DESC(completion_nsec, "Time in ns to complete a request in hardware. Default: 10,000ns"); | |
102 | ||
103 | static int hw_queue_depth = 64; | |
104 | module_param(hw_queue_depth, int, S_IRUGO); | |
105 | MODULE_PARM_DESC(hw_queue_depth, "Queue depth for each hardware queue. Default: 64"); | |
106 | ||
20005244 | 107 | static bool use_per_node_hctx = false; |
f2298c04 | 108 | module_param(use_per_node_hctx, bool, S_IRUGO); |
20005244 | 109 | MODULE_PARM_DESC(use_per_node_hctx, "Use per-node allocation for hardware context queues. Default: false"); |
f2298c04 JA |
110 | |
111 | static void put_tag(struct nullb_queue *nq, unsigned int tag) | |
112 | { | |
113 | clear_bit_unlock(tag, nq->tag_map); | |
114 | ||
115 | if (waitqueue_active(&nq->wait)) | |
116 | wake_up(&nq->wait); | |
117 | } | |
118 | ||
119 | static unsigned int get_tag(struct nullb_queue *nq) | |
120 | { | |
121 | unsigned int tag; | |
122 | ||
123 | do { | |
124 | tag = find_first_zero_bit(nq->tag_map, nq->queue_depth); | |
125 | if (tag >= nq->queue_depth) | |
126 | return -1U; | |
127 | } while (test_and_set_bit_lock(tag, nq->tag_map)); | |
128 | ||
129 | return tag; | |
130 | } | |
131 | ||
132 | static void free_cmd(struct nullb_cmd *cmd) | |
133 | { | |
134 | put_tag(cmd->nq, cmd->tag); | |
135 | } | |
136 | ||
137 | static struct nullb_cmd *__alloc_cmd(struct nullb_queue *nq) | |
138 | { | |
139 | struct nullb_cmd *cmd; | |
140 | unsigned int tag; | |
141 | ||
142 | tag = get_tag(nq); | |
143 | if (tag != -1U) { | |
144 | cmd = &nq->cmds[tag]; | |
145 | cmd->tag = tag; | |
146 | cmd->nq = nq; | |
147 | return cmd; | |
148 | } | |
149 | ||
150 | return NULL; | |
151 | } | |
152 | ||
153 | static struct nullb_cmd *alloc_cmd(struct nullb_queue *nq, int can_wait) | |
154 | { | |
155 | struct nullb_cmd *cmd; | |
156 | DEFINE_WAIT(wait); | |
157 | ||
158 | cmd = __alloc_cmd(nq); | |
159 | if (cmd || !can_wait) | |
160 | return cmd; | |
161 | ||
162 | do { | |
163 | prepare_to_wait(&nq->wait, &wait, TASK_UNINTERRUPTIBLE); | |
164 | cmd = __alloc_cmd(nq); | |
165 | if (cmd) | |
166 | break; | |
167 | ||
168 | io_schedule(); | |
169 | } while (1); | |
170 | ||
171 | finish_wait(&nq->wait, &wait); | |
172 | return cmd; | |
173 | } | |
174 | ||
175 | static void end_cmd(struct nullb_cmd *cmd) | |
176 | { | |
ce2c350b CH |
177 | switch (queue_mode) { |
178 | case NULL_Q_MQ: | |
179 | blk_mq_end_io(cmd->rq, 0); | |
180 | return; | |
181 | case NULL_Q_RQ: | |
182 | INIT_LIST_HEAD(&cmd->rq->queuelist); | |
183 | blk_end_request_all(cmd->rq, 0); | |
184 | break; | |
185 | case NULL_Q_BIO: | |
f2298c04 | 186 | bio_endio(cmd->bio, 0); |
ce2c350b CH |
187 | break; |
188 | } | |
f2298c04 | 189 | |
ce2c350b | 190 | free_cmd(cmd); |
f2298c04 JA |
191 | } |
192 | ||
193 | static enum hrtimer_restart null_cmd_timer_expired(struct hrtimer *timer) | |
194 | { | |
195 | struct completion_queue *cq; | |
196 | struct llist_node *entry; | |
197 | struct nullb_cmd *cmd; | |
198 | ||
199 | cq = &per_cpu(completion_queues, smp_processor_id()); | |
200 | ||
201 | while ((entry = llist_del_all(&cq->list)) != NULL) { | |
d7790b92 | 202 | entry = llist_reverse_order(entry); |
f2298c04 JA |
203 | do { |
204 | cmd = container_of(entry, struct nullb_cmd, ll_list); | |
205 | end_cmd(cmd); | |
206 | entry = entry->next; | |
207 | } while (entry); | |
208 | } | |
209 | ||
210 | return HRTIMER_NORESTART; | |
211 | } | |
212 | ||
213 | static void null_cmd_end_timer(struct nullb_cmd *cmd) | |
214 | { | |
215 | struct completion_queue *cq = &per_cpu(completion_queues, get_cpu()); | |
216 | ||
217 | cmd->ll_list.next = NULL; | |
218 | if (llist_add(&cmd->ll_list, &cq->list)) { | |
219 | ktime_t kt = ktime_set(0, completion_nsec); | |
220 | ||
221 | hrtimer_start(&cq->timer, kt, HRTIMER_MODE_REL); | |
222 | } | |
223 | ||
224 | put_cpu(); | |
225 | } | |
226 | ||
227 | static void null_softirq_done_fn(struct request *rq) | |
228 | { | |
9d74e257 | 229 | end_cmd(blk_mq_rq_to_pdu(rq)); |
f2298c04 JA |
230 | } |
231 | ||
f2298c04 JA |
232 | static inline void null_handle_cmd(struct nullb_cmd *cmd) |
233 | { | |
234 | /* Complete IO by inline, softirq or timer */ | |
235 | switch (irqmode) { | |
f2298c04 | 236 | case NULL_IRQ_SOFTIRQ: |
ce2c350b CH |
237 | switch (queue_mode) { |
238 | case NULL_Q_MQ: | |
239 | blk_mq_complete_request(cmd->rq); | |
240 | break; | |
241 | case NULL_Q_RQ: | |
242 | blk_complete_request(cmd->rq); | |
243 | break; | |
244 | case NULL_Q_BIO: | |
245 | /* | |
246 | * XXX: no proper submitting cpu information available. | |
247 | */ | |
248 | end_cmd(cmd); | |
249 | break; | |
250 | } | |
251 | break; | |
252 | case NULL_IRQ_NONE: | |
f2298c04 | 253 | end_cmd(cmd); |
f2298c04 JA |
254 | break; |
255 | case NULL_IRQ_TIMER: | |
256 | null_cmd_end_timer(cmd); | |
257 | break; | |
258 | } | |
259 | } | |
260 | ||
261 | static struct nullb_queue *nullb_to_queue(struct nullb *nullb) | |
262 | { | |
263 | int index = 0; | |
264 | ||
265 | if (nullb->nr_queues != 1) | |
266 | index = raw_smp_processor_id() / ((nr_cpu_ids + nullb->nr_queues - 1) / nullb->nr_queues); | |
267 | ||
268 | return &nullb->queues[index]; | |
269 | } | |
270 | ||
271 | static void null_queue_bio(struct request_queue *q, struct bio *bio) | |
272 | { | |
273 | struct nullb *nullb = q->queuedata; | |
274 | struct nullb_queue *nq = nullb_to_queue(nullb); | |
275 | struct nullb_cmd *cmd; | |
276 | ||
277 | cmd = alloc_cmd(nq, 1); | |
278 | cmd->bio = bio; | |
279 | ||
280 | null_handle_cmd(cmd); | |
281 | } | |
282 | ||
283 | static int null_rq_prep_fn(struct request_queue *q, struct request *req) | |
284 | { | |
285 | struct nullb *nullb = q->queuedata; | |
286 | struct nullb_queue *nq = nullb_to_queue(nullb); | |
287 | struct nullb_cmd *cmd; | |
288 | ||
289 | cmd = alloc_cmd(nq, 0); | |
290 | if (cmd) { | |
291 | cmd->rq = req; | |
292 | req->special = cmd; | |
293 | return BLKPREP_OK; | |
294 | } | |
295 | ||
296 | return BLKPREP_DEFER; | |
297 | } | |
298 | ||
299 | static void null_request_fn(struct request_queue *q) | |
300 | { | |
301 | struct request *rq; | |
302 | ||
303 | while ((rq = blk_fetch_request(q)) != NULL) { | |
304 | struct nullb_cmd *cmd = rq->special; | |
305 | ||
306 | spin_unlock_irq(q->queue_lock); | |
307 | null_handle_cmd(cmd); | |
308 | spin_lock_irq(q->queue_lock); | |
309 | } | |
310 | } | |
311 | ||
312 | static int null_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *rq) | |
313 | { | |
9d74e257 | 314 | struct nullb_cmd *cmd = blk_mq_rq_to_pdu(rq); |
f2298c04 JA |
315 | |
316 | cmd->rq = rq; | |
317 | cmd->nq = hctx->driver_data; | |
318 | ||
319 | null_handle_cmd(cmd); | |
320 | return BLK_MQ_RQ_QUEUE_OK; | |
321 | } | |
322 | ||
323 | static struct blk_mq_hw_ctx *null_alloc_hctx(struct blk_mq_reg *reg, unsigned int hctx_index) | |
324 | { | |
fc1bc354 MB |
325 | int b_size = DIV_ROUND_UP(reg->nr_hw_queues, nr_online_nodes); |
326 | int tip = (reg->nr_hw_queues % nr_online_nodes); | |
327 | int node = 0, i, n; | |
328 | ||
329 | /* | |
330 | * Split submit queues evenly wrt to the number of nodes. If uneven, | |
331 | * fill the first buckets with one extra, until the rest is filled with | |
332 | * no extra. | |
333 | */ | |
334 | for (i = 0, n = 1; i < hctx_index; i++, n++) { | |
335 | if (n % b_size == 0) { | |
336 | n = 0; | |
337 | node++; | |
338 | ||
339 | tip--; | |
340 | if (!tip) | |
341 | b_size = reg->nr_hw_queues / nr_online_nodes; | |
342 | } | |
343 | } | |
344 | ||
345 | /* | |
346 | * A node might not be online, therefore map the relative node id to the | |
347 | * real node id. | |
348 | */ | |
349 | for_each_online_node(n) { | |
350 | if (!node) | |
351 | break; | |
352 | node--; | |
353 | } | |
354 | ||
355 | return kzalloc_node(sizeof(struct blk_mq_hw_ctx), GFP_KERNEL, n); | |
f2298c04 JA |
356 | } |
357 | ||
358 | static void null_free_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_index) | |
359 | { | |
360 | kfree(hctx); | |
361 | } | |
362 | ||
2d263a78 MB |
363 | static void null_init_queue(struct nullb *nullb, struct nullb_queue *nq) |
364 | { | |
365 | BUG_ON(!nullb); | |
366 | BUG_ON(!nq); | |
367 | ||
368 | init_waitqueue_head(&nq->wait); | |
369 | nq->queue_depth = nullb->queue_depth; | |
370 | } | |
371 | ||
f2298c04 JA |
372 | static int null_init_hctx(struct blk_mq_hw_ctx *hctx, void *data, |
373 | unsigned int index) | |
374 | { | |
375 | struct nullb *nullb = data; | |
376 | struct nullb_queue *nq = &nullb->queues[index]; | |
377 | ||
f2298c04 | 378 | hctx->driver_data = nq; |
2d263a78 MB |
379 | null_init_queue(nullb, nq); |
380 | nullb->nr_queues++; | |
f2298c04 JA |
381 | |
382 | return 0; | |
383 | } | |
384 | ||
385 | static struct blk_mq_ops null_mq_ops = { | |
386 | .queue_rq = null_queue_rq, | |
387 | .map_queue = blk_mq_map_queue, | |
388 | .init_hctx = null_init_hctx, | |
ce2c350b | 389 | .complete = null_softirq_done_fn, |
f2298c04 JA |
390 | }; |
391 | ||
392 | static struct blk_mq_reg null_mq_reg = { | |
393 | .ops = &null_mq_ops, | |
394 | .queue_depth = 64, | |
395 | .cmd_size = sizeof(struct nullb_cmd), | |
396 | .flags = BLK_MQ_F_SHOULD_MERGE, | |
397 | }; | |
398 | ||
399 | static void null_del_dev(struct nullb *nullb) | |
400 | { | |
401 | list_del_init(&nullb->list); | |
402 | ||
403 | del_gendisk(nullb->disk); | |
518d00b7 | 404 | blk_cleanup_queue(nullb->q); |
f2298c04 JA |
405 | put_disk(nullb->disk); |
406 | kfree(nullb); | |
407 | } | |
408 | ||
409 | static int null_open(struct block_device *bdev, fmode_t mode) | |
410 | { | |
411 | return 0; | |
412 | } | |
413 | ||
414 | static void null_release(struct gendisk *disk, fmode_t mode) | |
415 | { | |
416 | } | |
417 | ||
418 | static const struct block_device_operations null_fops = { | |
419 | .owner = THIS_MODULE, | |
420 | .open = null_open, | |
421 | .release = null_release, | |
422 | }; | |
423 | ||
424 | static int setup_commands(struct nullb_queue *nq) | |
425 | { | |
426 | struct nullb_cmd *cmd; | |
427 | int i, tag_size; | |
428 | ||
429 | nq->cmds = kzalloc(nq->queue_depth * sizeof(*cmd), GFP_KERNEL); | |
430 | if (!nq->cmds) | |
2d263a78 | 431 | return -ENOMEM; |
f2298c04 JA |
432 | |
433 | tag_size = ALIGN(nq->queue_depth, BITS_PER_LONG) / BITS_PER_LONG; | |
434 | nq->tag_map = kzalloc(tag_size * sizeof(unsigned long), GFP_KERNEL); | |
435 | if (!nq->tag_map) { | |
436 | kfree(nq->cmds); | |
2d263a78 | 437 | return -ENOMEM; |
f2298c04 JA |
438 | } |
439 | ||
440 | for (i = 0; i < nq->queue_depth; i++) { | |
441 | cmd = &nq->cmds[i]; | |
442 | INIT_LIST_HEAD(&cmd->list); | |
443 | cmd->ll_list.next = NULL; | |
444 | cmd->tag = -1U; | |
445 | } | |
446 | ||
447 | return 0; | |
448 | } | |
449 | ||
450 | static void cleanup_queue(struct nullb_queue *nq) | |
451 | { | |
452 | kfree(nq->tag_map); | |
453 | kfree(nq->cmds); | |
454 | } | |
455 | ||
456 | static void cleanup_queues(struct nullb *nullb) | |
457 | { | |
458 | int i; | |
459 | ||
460 | for (i = 0; i < nullb->nr_queues; i++) | |
461 | cleanup_queue(&nullb->queues[i]); | |
462 | ||
463 | kfree(nullb->queues); | |
464 | } | |
465 | ||
466 | static int setup_queues(struct nullb *nullb) | |
467 | { | |
2d263a78 MB |
468 | nullb->queues = kzalloc(submit_queues * sizeof(struct nullb_queue), |
469 | GFP_KERNEL); | |
f2298c04 | 470 | if (!nullb->queues) |
2d263a78 | 471 | return -ENOMEM; |
f2298c04 JA |
472 | |
473 | nullb->nr_queues = 0; | |
474 | nullb->queue_depth = hw_queue_depth; | |
475 | ||
2d263a78 MB |
476 | return 0; |
477 | } | |
478 | ||
479 | static int init_driver_queues(struct nullb *nullb) | |
480 | { | |
481 | struct nullb_queue *nq; | |
482 | int i, ret = 0; | |
f2298c04 JA |
483 | |
484 | for (i = 0; i < submit_queues; i++) { | |
485 | nq = &nullb->queues[i]; | |
2d263a78 MB |
486 | |
487 | null_init_queue(nullb, nq); | |
488 | ||
489 | ret = setup_commands(nq); | |
490 | if (ret) | |
491 | goto err_queue; | |
f2298c04 JA |
492 | nullb->nr_queues++; |
493 | } | |
494 | ||
2d263a78 MB |
495 | return 0; |
496 | err_queue: | |
f2298c04 | 497 | cleanup_queues(nullb); |
2d263a78 | 498 | return ret; |
f2298c04 JA |
499 | } |
500 | ||
501 | static int null_add_dev(void) | |
502 | { | |
503 | struct gendisk *disk; | |
504 | struct nullb *nullb; | |
505 | sector_t size; | |
506 | ||
507 | nullb = kzalloc_node(sizeof(*nullb), GFP_KERNEL, home_node); | |
508 | if (!nullb) | |
509 | return -ENOMEM; | |
510 | ||
511 | spin_lock_init(&nullb->lock); | |
512 | ||
57053d8c MB |
513 | if (queue_mode == NULL_Q_MQ && use_per_node_hctx) |
514 | submit_queues = nr_online_nodes; | |
515 | ||
f2298c04 JA |
516 | if (setup_queues(nullb)) |
517 | goto err; | |
518 | ||
519 | if (queue_mode == NULL_Q_MQ) { | |
520 | null_mq_reg.numa_node = home_node; | |
521 | null_mq_reg.queue_depth = hw_queue_depth; | |
57053d8c | 522 | null_mq_reg.nr_hw_queues = submit_queues; |
f2298c04 JA |
523 | |
524 | if (use_per_node_hctx) { | |
525 | null_mq_reg.ops->alloc_hctx = null_alloc_hctx; | |
526 | null_mq_reg.ops->free_hctx = null_free_hctx; | |
f2298c04 JA |
527 | } else { |
528 | null_mq_reg.ops->alloc_hctx = blk_mq_alloc_single_hw_queue; | |
529 | null_mq_reg.ops->free_hctx = blk_mq_free_single_hw_queue; | |
f2298c04 JA |
530 | } |
531 | ||
532 | nullb->q = blk_mq_init_queue(&null_mq_reg, nullb); | |
533 | } else if (queue_mode == NULL_Q_BIO) { | |
534 | nullb->q = blk_alloc_queue_node(GFP_KERNEL, home_node); | |
535 | blk_queue_make_request(nullb->q, null_queue_bio); | |
2d263a78 | 536 | init_driver_queues(nullb); |
f2298c04 JA |
537 | } else { |
538 | nullb->q = blk_init_queue_node(null_request_fn, &nullb->lock, home_node); | |
539 | blk_queue_prep_rq(nullb->q, null_rq_prep_fn); | |
540 | if (nullb->q) | |
541 | blk_queue_softirq_done(nullb->q, null_softirq_done_fn); | |
2d263a78 | 542 | init_driver_queues(nullb); |
f2298c04 JA |
543 | } |
544 | ||
545 | if (!nullb->q) | |
546 | goto queue_fail; | |
547 | ||
548 | nullb->q->queuedata = nullb; | |
549 | queue_flag_set_unlocked(QUEUE_FLAG_NONROT, nullb->q); | |
550 | ||
551 | disk = nullb->disk = alloc_disk_node(1, home_node); | |
552 | if (!disk) { | |
553 | queue_fail: | |
518d00b7 | 554 | blk_cleanup_queue(nullb->q); |
f2298c04 JA |
555 | cleanup_queues(nullb); |
556 | err: | |
557 | kfree(nullb); | |
558 | return -ENOMEM; | |
559 | } | |
560 | ||
561 | mutex_lock(&lock); | |
562 | list_add_tail(&nullb->list, &nullb_list); | |
563 | nullb->index = nullb_indexes++; | |
564 | mutex_unlock(&lock); | |
565 | ||
566 | blk_queue_logical_block_size(nullb->q, bs); | |
567 | blk_queue_physical_block_size(nullb->q, bs); | |
568 | ||
569 | size = gb * 1024 * 1024 * 1024ULL; | |
570 | sector_div(size, bs); | |
571 | set_capacity(disk, size); | |
572 | ||
573 | disk->flags |= GENHD_FL_EXT_DEVT; | |
574 | disk->major = null_major; | |
575 | disk->first_minor = nullb->index; | |
576 | disk->fops = &null_fops; | |
577 | disk->private_data = nullb; | |
578 | disk->queue = nullb->q; | |
579 | sprintf(disk->disk_name, "nullb%d", nullb->index); | |
580 | add_disk(disk); | |
581 | return 0; | |
582 | } | |
583 | ||
584 | static int __init null_init(void) | |
585 | { | |
586 | unsigned int i; | |
587 | ||
9967d8ac R |
588 | if (bs > PAGE_SIZE) { |
589 | pr_warn("null_blk: invalid block size\n"); | |
590 | pr_warn("null_blk: defaults block size to %lu\n", PAGE_SIZE); | |
591 | bs = PAGE_SIZE; | |
592 | } | |
f2298c04 | 593 | |
d15ee6b1 | 594 | if (queue_mode == NULL_Q_MQ && use_per_node_hctx) { |
fc1bc354 | 595 | if (submit_queues < nr_online_nodes) { |
d15ee6b1 MB |
596 | pr_warn("null_blk: submit_queues param is set to %u.", |
597 | nr_online_nodes); | |
fc1bc354 MB |
598 | submit_queues = nr_online_nodes; |
599 | } | |
d15ee6b1 | 600 | } else if (submit_queues > nr_cpu_ids) |
f2298c04 JA |
601 | submit_queues = nr_cpu_ids; |
602 | else if (!submit_queues) | |
603 | submit_queues = 1; | |
604 | ||
605 | mutex_init(&lock); | |
606 | ||
607 | /* Initialize a separate list for each CPU for issuing softirqs */ | |
608 | for_each_possible_cpu(i) { | |
609 | struct completion_queue *cq = &per_cpu(completion_queues, i); | |
610 | ||
611 | init_llist_head(&cq->list); | |
612 | ||
613 | if (irqmode != NULL_IRQ_TIMER) | |
614 | continue; | |
615 | ||
616 | hrtimer_init(&cq->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
617 | cq->timer.function = null_cmd_timer_expired; | |
618 | } | |
619 | ||
620 | null_major = register_blkdev(0, "nullb"); | |
621 | if (null_major < 0) | |
622 | return null_major; | |
623 | ||
624 | for (i = 0; i < nr_devices; i++) { | |
625 | if (null_add_dev()) { | |
626 | unregister_blkdev(null_major, "nullb"); | |
627 | return -EINVAL; | |
628 | } | |
629 | } | |
630 | ||
631 | pr_info("null: module loaded\n"); | |
632 | return 0; | |
633 | } | |
634 | ||
635 | static void __exit null_exit(void) | |
636 | { | |
637 | struct nullb *nullb; | |
638 | ||
639 | unregister_blkdev(null_major, "nullb"); | |
640 | ||
641 | mutex_lock(&lock); | |
642 | while (!list_empty(&nullb_list)) { | |
643 | nullb = list_entry(nullb_list.next, struct nullb, list); | |
644 | null_del_dev(nullb); | |
645 | } | |
646 | mutex_unlock(&lock); | |
647 | } | |
648 | ||
649 | module_init(null_init); | |
650 | module_exit(null_exit); | |
651 | ||
652 | MODULE_AUTHOR("Jens Axboe <jaxboe@fusionio.com>"); | |
653 | MODULE_LICENSE("GPL"); |