]>
Commit | Line | Data |
---|---|---|
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, | |
63 | ||
64 | NULL_Q_BIO = 0, | |
65 | NULL_Q_RQ = 1, | |
66 | NULL_Q_MQ = 2, | |
67 | }; | |
68 | ||
2d263a78 | 69 | static int submit_queues; |
f2298c04 JA |
70 | module_param(submit_queues, int, S_IRUGO); |
71 | MODULE_PARM_DESC(submit_queues, "Number of submission queues"); | |
72 | ||
73 | static int home_node = NUMA_NO_NODE; | |
74 | module_param(home_node, int, S_IRUGO); | |
75 | MODULE_PARM_DESC(home_node, "Home node for the device"); | |
76 | ||
77 | static int queue_mode = NULL_Q_MQ; | |
78 | module_param(queue_mode, int, S_IRUGO); | |
79 | MODULE_PARM_DESC(use_mq, "Use blk-mq interface (0=bio,1=rq,2=multiqueue)"); | |
80 | ||
81 | static int gb = 250; | |
82 | module_param(gb, int, S_IRUGO); | |
83 | MODULE_PARM_DESC(gb, "Size in GB"); | |
84 | ||
85 | static int bs = 512; | |
86 | module_param(bs, int, S_IRUGO); | |
87 | MODULE_PARM_DESC(bs, "Block size (in bytes)"); | |
88 | ||
89 | static int nr_devices = 2; | |
90 | module_param(nr_devices, int, S_IRUGO); | |
91 | MODULE_PARM_DESC(nr_devices, "Number of devices to register"); | |
92 | ||
93 | static int irqmode = NULL_IRQ_SOFTIRQ; | |
94 | module_param(irqmode, int, S_IRUGO); | |
95 | MODULE_PARM_DESC(irqmode, "IRQ completion handler. 0-none, 1-softirq, 2-timer"); | |
96 | ||
97 | static int completion_nsec = 10000; | |
98 | module_param(completion_nsec, int, S_IRUGO); | |
99 | MODULE_PARM_DESC(completion_nsec, "Time in ns to complete a request in hardware. Default: 10,000ns"); | |
100 | ||
101 | static int hw_queue_depth = 64; | |
102 | module_param(hw_queue_depth, int, S_IRUGO); | |
103 | MODULE_PARM_DESC(hw_queue_depth, "Queue depth for each hardware queue. Default: 64"); | |
104 | ||
20005244 | 105 | static bool use_per_node_hctx = false; |
f2298c04 | 106 | module_param(use_per_node_hctx, bool, S_IRUGO); |
20005244 | 107 | MODULE_PARM_DESC(use_per_node_hctx, "Use per-node allocation for hardware context queues. Default: false"); |
f2298c04 JA |
108 | |
109 | static void put_tag(struct nullb_queue *nq, unsigned int tag) | |
110 | { | |
111 | clear_bit_unlock(tag, nq->tag_map); | |
112 | ||
113 | if (waitqueue_active(&nq->wait)) | |
114 | wake_up(&nq->wait); | |
115 | } | |
116 | ||
117 | static unsigned int get_tag(struct nullb_queue *nq) | |
118 | { | |
119 | unsigned int tag; | |
120 | ||
121 | do { | |
122 | tag = find_first_zero_bit(nq->tag_map, nq->queue_depth); | |
123 | if (tag >= nq->queue_depth) | |
124 | return -1U; | |
125 | } while (test_and_set_bit_lock(tag, nq->tag_map)); | |
126 | ||
127 | return tag; | |
128 | } | |
129 | ||
130 | static void free_cmd(struct nullb_cmd *cmd) | |
131 | { | |
132 | put_tag(cmd->nq, cmd->tag); | |
133 | } | |
134 | ||
135 | static struct nullb_cmd *__alloc_cmd(struct nullb_queue *nq) | |
136 | { | |
137 | struct nullb_cmd *cmd; | |
138 | unsigned int tag; | |
139 | ||
140 | tag = get_tag(nq); | |
141 | if (tag != -1U) { | |
142 | cmd = &nq->cmds[tag]; | |
143 | cmd->tag = tag; | |
144 | cmd->nq = nq; | |
145 | return cmd; | |
146 | } | |
147 | ||
148 | return NULL; | |
149 | } | |
150 | ||
151 | static struct nullb_cmd *alloc_cmd(struct nullb_queue *nq, int can_wait) | |
152 | { | |
153 | struct nullb_cmd *cmd; | |
154 | DEFINE_WAIT(wait); | |
155 | ||
156 | cmd = __alloc_cmd(nq); | |
157 | if (cmd || !can_wait) | |
158 | return cmd; | |
159 | ||
160 | do { | |
161 | prepare_to_wait(&nq->wait, &wait, TASK_UNINTERRUPTIBLE); | |
162 | cmd = __alloc_cmd(nq); | |
163 | if (cmd) | |
164 | break; | |
165 | ||
166 | io_schedule(); | |
167 | } while (1); | |
168 | ||
169 | finish_wait(&nq->wait, &wait); | |
170 | return cmd; | |
171 | } | |
172 | ||
173 | static void end_cmd(struct nullb_cmd *cmd) | |
174 | { | |
175 | if (cmd->rq) { | |
176 | if (queue_mode == NULL_Q_MQ) | |
177 | blk_mq_end_io(cmd->rq, 0); | |
178 | else { | |
179 | INIT_LIST_HEAD(&cmd->rq->queuelist); | |
180 | blk_end_request_all(cmd->rq, 0); | |
181 | } | |
182 | } else if (cmd->bio) | |
183 | bio_endio(cmd->bio, 0); | |
184 | ||
185 | if (queue_mode != NULL_Q_MQ) | |
186 | free_cmd(cmd); | |
187 | } | |
188 | ||
189 | static enum hrtimer_restart null_cmd_timer_expired(struct hrtimer *timer) | |
190 | { | |
191 | struct completion_queue *cq; | |
192 | struct llist_node *entry; | |
193 | struct nullb_cmd *cmd; | |
194 | ||
195 | cq = &per_cpu(completion_queues, smp_processor_id()); | |
196 | ||
197 | while ((entry = llist_del_all(&cq->list)) != NULL) { | |
d7790b92 | 198 | entry = llist_reverse_order(entry); |
f2298c04 JA |
199 | do { |
200 | cmd = container_of(entry, struct nullb_cmd, ll_list); | |
201 | end_cmd(cmd); | |
202 | entry = entry->next; | |
203 | } while (entry); | |
204 | } | |
205 | ||
206 | return HRTIMER_NORESTART; | |
207 | } | |
208 | ||
209 | static void null_cmd_end_timer(struct nullb_cmd *cmd) | |
210 | { | |
211 | struct completion_queue *cq = &per_cpu(completion_queues, get_cpu()); | |
212 | ||
213 | cmd->ll_list.next = NULL; | |
214 | if (llist_add(&cmd->ll_list, &cq->list)) { | |
215 | ktime_t kt = ktime_set(0, completion_nsec); | |
216 | ||
217 | hrtimer_start(&cq->timer, kt, HRTIMER_MODE_REL); | |
218 | } | |
219 | ||
220 | put_cpu(); | |
221 | } | |
222 | ||
223 | static void null_softirq_done_fn(struct request *rq) | |
224 | { | |
225 | blk_end_request_all(rq, 0); | |
226 | } | |
227 | ||
044c8d4b | 228 | #ifdef CONFIG_SMP |
f2298c04 JA |
229 | |
230 | static void null_ipi_cmd_end_io(void *data) | |
231 | { | |
232 | struct completion_queue *cq; | |
233 | struct llist_node *entry, *next; | |
234 | struct nullb_cmd *cmd; | |
235 | ||
236 | cq = &per_cpu(completion_queues, smp_processor_id()); | |
237 | ||
238 | entry = llist_del_all(&cq->list); | |
d7790b92 | 239 | entry = llist_reverse_order(entry); |
f2298c04 JA |
240 | |
241 | while (entry) { | |
242 | next = entry->next; | |
243 | cmd = llist_entry(entry, struct nullb_cmd, ll_list); | |
244 | end_cmd(cmd); | |
245 | entry = next; | |
246 | } | |
247 | } | |
248 | ||
249 | static void null_cmd_end_ipi(struct nullb_cmd *cmd) | |
250 | { | |
251 | struct call_single_data *data = &cmd->csd; | |
252 | int cpu = get_cpu(); | |
253 | struct completion_queue *cq = &per_cpu(completion_queues, cpu); | |
254 | ||
255 | cmd->ll_list.next = NULL; | |
256 | ||
257 | if (llist_add(&cmd->ll_list, &cq->list)) { | |
258 | data->func = null_ipi_cmd_end_io; | |
259 | data->flags = 0; | |
260 | __smp_call_function_single(cpu, data, 0); | |
261 | } | |
262 | ||
263 | put_cpu(); | |
264 | } | |
265 | ||
044c8d4b | 266 | #endif /* CONFIG_SMP */ |
f2298c04 JA |
267 | |
268 | static inline void null_handle_cmd(struct nullb_cmd *cmd) | |
269 | { | |
270 | /* Complete IO by inline, softirq or timer */ | |
271 | switch (irqmode) { | |
272 | case NULL_IRQ_NONE: | |
273 | end_cmd(cmd); | |
274 | break; | |
275 | case NULL_IRQ_SOFTIRQ: | |
044c8d4b | 276 | #ifdef CONFIG_SMP |
f2298c04 JA |
277 | null_cmd_end_ipi(cmd); |
278 | #else | |
279 | end_cmd(cmd); | |
280 | #endif | |
281 | break; | |
282 | case NULL_IRQ_TIMER: | |
283 | null_cmd_end_timer(cmd); | |
284 | break; | |
285 | } | |
286 | } | |
287 | ||
288 | static struct nullb_queue *nullb_to_queue(struct nullb *nullb) | |
289 | { | |
290 | int index = 0; | |
291 | ||
292 | if (nullb->nr_queues != 1) | |
293 | index = raw_smp_processor_id() / ((nr_cpu_ids + nullb->nr_queues - 1) / nullb->nr_queues); | |
294 | ||
295 | return &nullb->queues[index]; | |
296 | } | |
297 | ||
298 | static void null_queue_bio(struct request_queue *q, struct bio *bio) | |
299 | { | |
300 | struct nullb *nullb = q->queuedata; | |
301 | struct nullb_queue *nq = nullb_to_queue(nullb); | |
302 | struct nullb_cmd *cmd; | |
303 | ||
304 | cmd = alloc_cmd(nq, 1); | |
305 | cmd->bio = bio; | |
306 | ||
307 | null_handle_cmd(cmd); | |
308 | } | |
309 | ||
310 | static int null_rq_prep_fn(struct request_queue *q, struct request *req) | |
311 | { | |
312 | struct nullb *nullb = q->queuedata; | |
313 | struct nullb_queue *nq = nullb_to_queue(nullb); | |
314 | struct nullb_cmd *cmd; | |
315 | ||
316 | cmd = alloc_cmd(nq, 0); | |
317 | if (cmd) { | |
318 | cmd->rq = req; | |
319 | req->special = cmd; | |
320 | return BLKPREP_OK; | |
321 | } | |
322 | ||
323 | return BLKPREP_DEFER; | |
324 | } | |
325 | ||
326 | static void null_request_fn(struct request_queue *q) | |
327 | { | |
328 | struct request *rq; | |
329 | ||
330 | while ((rq = blk_fetch_request(q)) != NULL) { | |
331 | struct nullb_cmd *cmd = rq->special; | |
332 | ||
333 | spin_unlock_irq(q->queue_lock); | |
334 | null_handle_cmd(cmd); | |
335 | spin_lock_irq(q->queue_lock); | |
336 | } | |
337 | } | |
338 | ||
339 | static int null_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *rq) | |
340 | { | |
341 | struct nullb_cmd *cmd = rq->special; | |
342 | ||
343 | cmd->rq = rq; | |
344 | cmd->nq = hctx->driver_data; | |
345 | ||
346 | null_handle_cmd(cmd); | |
347 | return BLK_MQ_RQ_QUEUE_OK; | |
348 | } | |
349 | ||
350 | static struct blk_mq_hw_ctx *null_alloc_hctx(struct blk_mq_reg *reg, unsigned int hctx_index) | |
351 | { | |
fc1bc354 MB |
352 | int b_size = DIV_ROUND_UP(reg->nr_hw_queues, nr_online_nodes); |
353 | int tip = (reg->nr_hw_queues % nr_online_nodes); | |
354 | int node = 0, i, n; | |
355 | ||
356 | /* | |
357 | * Split submit queues evenly wrt to the number of nodes. If uneven, | |
358 | * fill the first buckets with one extra, until the rest is filled with | |
359 | * no extra. | |
360 | */ | |
361 | for (i = 0, n = 1; i < hctx_index; i++, n++) { | |
362 | if (n % b_size == 0) { | |
363 | n = 0; | |
364 | node++; | |
365 | ||
366 | tip--; | |
367 | if (!tip) | |
368 | b_size = reg->nr_hw_queues / nr_online_nodes; | |
369 | } | |
370 | } | |
371 | ||
372 | /* | |
373 | * A node might not be online, therefore map the relative node id to the | |
374 | * real node id. | |
375 | */ | |
376 | for_each_online_node(n) { | |
377 | if (!node) | |
378 | break; | |
379 | node--; | |
380 | } | |
381 | ||
382 | return kzalloc_node(sizeof(struct blk_mq_hw_ctx), GFP_KERNEL, n); | |
f2298c04 JA |
383 | } |
384 | ||
385 | static void null_free_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_index) | |
386 | { | |
387 | kfree(hctx); | |
388 | } | |
389 | ||
2d263a78 MB |
390 | static void null_init_queue(struct nullb *nullb, struct nullb_queue *nq) |
391 | { | |
392 | BUG_ON(!nullb); | |
393 | BUG_ON(!nq); | |
394 | ||
395 | init_waitqueue_head(&nq->wait); | |
396 | nq->queue_depth = nullb->queue_depth; | |
397 | } | |
398 | ||
f2298c04 JA |
399 | static int null_init_hctx(struct blk_mq_hw_ctx *hctx, void *data, |
400 | unsigned int index) | |
401 | { | |
402 | struct nullb *nullb = data; | |
403 | struct nullb_queue *nq = &nullb->queues[index]; | |
404 | ||
f2298c04 | 405 | hctx->driver_data = nq; |
2d263a78 MB |
406 | null_init_queue(nullb, nq); |
407 | nullb->nr_queues++; | |
f2298c04 JA |
408 | |
409 | return 0; | |
410 | } | |
411 | ||
412 | static struct blk_mq_ops null_mq_ops = { | |
413 | .queue_rq = null_queue_rq, | |
414 | .map_queue = blk_mq_map_queue, | |
415 | .init_hctx = null_init_hctx, | |
416 | }; | |
417 | ||
418 | static struct blk_mq_reg null_mq_reg = { | |
419 | .ops = &null_mq_ops, | |
420 | .queue_depth = 64, | |
421 | .cmd_size = sizeof(struct nullb_cmd), | |
422 | .flags = BLK_MQ_F_SHOULD_MERGE, | |
423 | }; | |
424 | ||
425 | static void null_del_dev(struct nullb *nullb) | |
426 | { | |
427 | list_del_init(&nullb->list); | |
428 | ||
429 | del_gendisk(nullb->disk); | |
518d00b7 | 430 | blk_cleanup_queue(nullb->q); |
f2298c04 JA |
431 | put_disk(nullb->disk); |
432 | kfree(nullb); | |
433 | } | |
434 | ||
435 | static int null_open(struct block_device *bdev, fmode_t mode) | |
436 | { | |
437 | return 0; | |
438 | } | |
439 | ||
440 | static void null_release(struct gendisk *disk, fmode_t mode) | |
441 | { | |
442 | } | |
443 | ||
444 | static const struct block_device_operations null_fops = { | |
445 | .owner = THIS_MODULE, | |
446 | .open = null_open, | |
447 | .release = null_release, | |
448 | }; | |
449 | ||
450 | static int setup_commands(struct nullb_queue *nq) | |
451 | { | |
452 | struct nullb_cmd *cmd; | |
453 | int i, tag_size; | |
454 | ||
455 | nq->cmds = kzalloc(nq->queue_depth * sizeof(*cmd), GFP_KERNEL); | |
456 | if (!nq->cmds) | |
2d263a78 | 457 | return -ENOMEM; |
f2298c04 JA |
458 | |
459 | tag_size = ALIGN(nq->queue_depth, BITS_PER_LONG) / BITS_PER_LONG; | |
460 | nq->tag_map = kzalloc(tag_size * sizeof(unsigned long), GFP_KERNEL); | |
461 | if (!nq->tag_map) { | |
462 | kfree(nq->cmds); | |
2d263a78 | 463 | return -ENOMEM; |
f2298c04 JA |
464 | } |
465 | ||
466 | for (i = 0; i < nq->queue_depth; i++) { | |
467 | cmd = &nq->cmds[i]; | |
468 | INIT_LIST_HEAD(&cmd->list); | |
469 | cmd->ll_list.next = NULL; | |
470 | cmd->tag = -1U; | |
471 | } | |
472 | ||
473 | return 0; | |
474 | } | |
475 | ||
476 | static void cleanup_queue(struct nullb_queue *nq) | |
477 | { | |
478 | kfree(nq->tag_map); | |
479 | kfree(nq->cmds); | |
480 | } | |
481 | ||
482 | static void cleanup_queues(struct nullb *nullb) | |
483 | { | |
484 | int i; | |
485 | ||
486 | for (i = 0; i < nullb->nr_queues; i++) | |
487 | cleanup_queue(&nullb->queues[i]); | |
488 | ||
489 | kfree(nullb->queues); | |
490 | } | |
491 | ||
492 | static int setup_queues(struct nullb *nullb) | |
493 | { | |
2d263a78 MB |
494 | nullb->queues = kzalloc(submit_queues * sizeof(struct nullb_queue), |
495 | GFP_KERNEL); | |
f2298c04 | 496 | if (!nullb->queues) |
2d263a78 | 497 | return -ENOMEM; |
f2298c04 JA |
498 | |
499 | nullb->nr_queues = 0; | |
500 | nullb->queue_depth = hw_queue_depth; | |
501 | ||
2d263a78 MB |
502 | return 0; |
503 | } | |
504 | ||
505 | static int init_driver_queues(struct nullb *nullb) | |
506 | { | |
507 | struct nullb_queue *nq; | |
508 | int i, ret = 0; | |
f2298c04 JA |
509 | |
510 | for (i = 0; i < submit_queues; i++) { | |
511 | nq = &nullb->queues[i]; | |
2d263a78 MB |
512 | |
513 | null_init_queue(nullb, nq); | |
514 | ||
515 | ret = setup_commands(nq); | |
516 | if (ret) | |
517 | goto err_queue; | |
f2298c04 JA |
518 | nullb->nr_queues++; |
519 | } | |
520 | ||
2d263a78 MB |
521 | return 0; |
522 | err_queue: | |
f2298c04 | 523 | cleanup_queues(nullb); |
2d263a78 | 524 | return ret; |
f2298c04 JA |
525 | } |
526 | ||
527 | static int null_add_dev(void) | |
528 | { | |
529 | struct gendisk *disk; | |
530 | struct nullb *nullb; | |
531 | sector_t size; | |
532 | ||
533 | nullb = kzalloc_node(sizeof(*nullb), GFP_KERNEL, home_node); | |
534 | if (!nullb) | |
535 | return -ENOMEM; | |
536 | ||
537 | spin_lock_init(&nullb->lock); | |
538 | ||
57053d8c MB |
539 | if (queue_mode == NULL_Q_MQ && use_per_node_hctx) |
540 | submit_queues = nr_online_nodes; | |
541 | ||
f2298c04 JA |
542 | if (setup_queues(nullb)) |
543 | goto err; | |
544 | ||
545 | if (queue_mode == NULL_Q_MQ) { | |
546 | null_mq_reg.numa_node = home_node; | |
547 | null_mq_reg.queue_depth = hw_queue_depth; | |
57053d8c | 548 | null_mq_reg.nr_hw_queues = submit_queues; |
f2298c04 JA |
549 | |
550 | if (use_per_node_hctx) { | |
551 | null_mq_reg.ops->alloc_hctx = null_alloc_hctx; | |
552 | null_mq_reg.ops->free_hctx = null_free_hctx; | |
f2298c04 JA |
553 | } else { |
554 | null_mq_reg.ops->alloc_hctx = blk_mq_alloc_single_hw_queue; | |
555 | null_mq_reg.ops->free_hctx = blk_mq_free_single_hw_queue; | |
f2298c04 JA |
556 | } |
557 | ||
558 | nullb->q = blk_mq_init_queue(&null_mq_reg, nullb); | |
559 | } else if (queue_mode == NULL_Q_BIO) { | |
560 | nullb->q = blk_alloc_queue_node(GFP_KERNEL, home_node); | |
561 | blk_queue_make_request(nullb->q, null_queue_bio); | |
2d263a78 | 562 | init_driver_queues(nullb); |
f2298c04 JA |
563 | } else { |
564 | nullb->q = blk_init_queue_node(null_request_fn, &nullb->lock, home_node); | |
565 | blk_queue_prep_rq(nullb->q, null_rq_prep_fn); | |
566 | if (nullb->q) | |
567 | blk_queue_softirq_done(nullb->q, null_softirq_done_fn); | |
2d263a78 | 568 | init_driver_queues(nullb); |
f2298c04 JA |
569 | } |
570 | ||
571 | if (!nullb->q) | |
572 | goto queue_fail; | |
573 | ||
574 | nullb->q->queuedata = nullb; | |
575 | queue_flag_set_unlocked(QUEUE_FLAG_NONROT, nullb->q); | |
576 | ||
577 | disk = nullb->disk = alloc_disk_node(1, home_node); | |
578 | if (!disk) { | |
579 | queue_fail: | |
518d00b7 | 580 | blk_cleanup_queue(nullb->q); |
f2298c04 JA |
581 | cleanup_queues(nullb); |
582 | err: | |
583 | kfree(nullb); | |
584 | return -ENOMEM; | |
585 | } | |
586 | ||
587 | mutex_lock(&lock); | |
588 | list_add_tail(&nullb->list, &nullb_list); | |
589 | nullb->index = nullb_indexes++; | |
590 | mutex_unlock(&lock); | |
591 | ||
592 | blk_queue_logical_block_size(nullb->q, bs); | |
593 | blk_queue_physical_block_size(nullb->q, bs); | |
594 | ||
595 | size = gb * 1024 * 1024 * 1024ULL; | |
596 | sector_div(size, bs); | |
597 | set_capacity(disk, size); | |
598 | ||
599 | disk->flags |= GENHD_FL_EXT_DEVT; | |
600 | disk->major = null_major; | |
601 | disk->first_minor = nullb->index; | |
602 | disk->fops = &null_fops; | |
603 | disk->private_data = nullb; | |
604 | disk->queue = nullb->q; | |
605 | sprintf(disk->disk_name, "nullb%d", nullb->index); | |
606 | add_disk(disk); | |
607 | return 0; | |
608 | } | |
609 | ||
610 | static int __init null_init(void) | |
611 | { | |
612 | unsigned int i; | |
613 | ||
044c8d4b | 614 | #if !defined(CONFIG_SMP) |
f2298c04 JA |
615 | if (irqmode == NULL_IRQ_SOFTIRQ) { |
616 | pr_warn("null_blk: softirq completions not available.\n"); | |
617 | pr_warn("null_blk: using direct completions.\n"); | |
618 | irqmode = NULL_IRQ_NONE; | |
619 | } | |
620 | #endif | |
9967d8ac R |
621 | if (bs > PAGE_SIZE) { |
622 | pr_warn("null_blk: invalid block size\n"); | |
623 | pr_warn("null_blk: defaults block size to %lu\n", PAGE_SIZE); | |
624 | bs = PAGE_SIZE; | |
625 | } | |
f2298c04 | 626 | |
d15ee6b1 | 627 | if (queue_mode == NULL_Q_MQ && use_per_node_hctx) { |
fc1bc354 | 628 | if (submit_queues < nr_online_nodes) { |
d15ee6b1 MB |
629 | pr_warn("null_blk: submit_queues param is set to %u.", |
630 | nr_online_nodes); | |
fc1bc354 MB |
631 | submit_queues = nr_online_nodes; |
632 | } | |
d15ee6b1 | 633 | } else if (submit_queues > nr_cpu_ids) |
f2298c04 JA |
634 | submit_queues = nr_cpu_ids; |
635 | else if (!submit_queues) | |
636 | submit_queues = 1; | |
637 | ||
638 | mutex_init(&lock); | |
639 | ||
640 | /* Initialize a separate list for each CPU for issuing softirqs */ | |
641 | for_each_possible_cpu(i) { | |
642 | struct completion_queue *cq = &per_cpu(completion_queues, i); | |
643 | ||
644 | init_llist_head(&cq->list); | |
645 | ||
646 | if (irqmode != NULL_IRQ_TIMER) | |
647 | continue; | |
648 | ||
649 | hrtimer_init(&cq->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
650 | cq->timer.function = null_cmd_timer_expired; | |
651 | } | |
652 | ||
653 | null_major = register_blkdev(0, "nullb"); | |
654 | if (null_major < 0) | |
655 | return null_major; | |
656 | ||
657 | for (i = 0; i < nr_devices; i++) { | |
658 | if (null_add_dev()) { | |
659 | unregister_blkdev(null_major, "nullb"); | |
660 | return -EINVAL; | |
661 | } | |
662 | } | |
663 | ||
664 | pr_info("null: module loaded\n"); | |
665 | return 0; | |
666 | } | |
667 | ||
668 | static void __exit null_exit(void) | |
669 | { | |
670 | struct nullb *nullb; | |
671 | ||
672 | unregister_blkdev(null_major, "nullb"); | |
673 | ||
674 | mutex_lock(&lock); | |
675 | while (!list_empty(&nullb_list)) { | |
676 | nullb = list_entry(nullb_list.next, struct nullb, list); | |
677 | null_del_dev(nullb); | |
678 | } | |
679 | mutex_unlock(&lock); | |
680 | } | |
681 | ||
682 | module_init(null_init); | |
683 | module_exit(null_exit); | |
684 | ||
685 | MODULE_AUTHOR("Jens Axboe <jaxboe@fusionio.com>"); | |
686 | MODULE_LICENSE("GPL"); |