xref: /openbmc/linux/block/blk-mq-sysfs.c (revision 8730046c) 
1 #include <linux/kernel.h>
2 #include <linux/module.h>
3 #include <linux/backing-dev.h>
4 #include <linux/bio.h>
5 #include <linux/blkdev.h>
6 #include <linux/mm.h>
7 #include <linux/init.h>
8 #include <linux/slab.h>
9 #include <linux/workqueue.h>
10 #include <linux/smp.h>
11 
12 #include <linux/blk-mq.h>
13 #include "blk-mq.h"
14 #include "blk-mq-tag.h"
15 
16 static void blk_mq_sysfs_release(struct kobject *kobj)
17 {
18 }
19 
20 struct blk_mq_ctx_sysfs_entry {
21 	struct attribute attr;
22 	ssize_t (*show)(struct blk_mq_ctx *, char *);
23 	ssize_t (*store)(struct blk_mq_ctx *, const char *, size_t);
24 };
25 
26 struct blk_mq_hw_ctx_sysfs_entry {
27 	struct attribute attr;
28 	ssize_t (*show)(struct blk_mq_hw_ctx *, char *);
29 	ssize_t (*store)(struct blk_mq_hw_ctx *, const char *, size_t);
30 };
31 
32 static ssize_t blk_mq_sysfs_show(struct kobject *kobj, struct attribute *attr,
33 				 char *page)
34 {
35 	struct blk_mq_ctx_sysfs_entry *entry;
36 	struct blk_mq_ctx *ctx;
37 	struct request_queue *q;
38 	ssize_t res;
39 
40 	entry = container_of(attr, struct blk_mq_ctx_sysfs_entry, attr);
41 	ctx = container_of(kobj, struct blk_mq_ctx, kobj);
42 	q = ctx->queue;
43 
44 	if (!entry->show)
45 		return -EIO;
46 
47 	res = -ENOENT;
48 	mutex_lock(&q->sysfs_lock);
49 	if (!blk_queue_dying(q))
50 		res = entry->show(ctx, page);
51 	mutex_unlock(&q->sysfs_lock);
52 	return res;
53 }
54 
55 static ssize_t blk_mq_sysfs_store(struct kobject *kobj, struct attribute *attr,
56 				  const char *page, size_t length)
57 {
58 	struct blk_mq_ctx_sysfs_entry *entry;
59 	struct blk_mq_ctx *ctx;
60 	struct request_queue *q;
61 	ssize_t res;
62 
63 	entry = container_of(attr, struct blk_mq_ctx_sysfs_entry, attr);
64 	ctx = container_of(kobj, struct blk_mq_ctx, kobj);
65 	q = ctx->queue;
66 
67 	if (!entry->store)
68 		return -EIO;
69 
70 	res = -ENOENT;
71 	mutex_lock(&q->sysfs_lock);
72 	if (!blk_queue_dying(q))
73 		res = entry->store(ctx, page, length);
74 	mutex_unlock(&q->sysfs_lock);
75 	return res;
76 }
77 
78 static ssize_t blk_mq_hw_sysfs_show(struct kobject *kobj,
79 				    struct attribute *attr, char *page)
80 {
81 	struct blk_mq_hw_ctx_sysfs_entry *entry;
82 	struct blk_mq_hw_ctx *hctx;
83 	struct request_queue *q;
84 	ssize_t res;
85 
86 	entry = container_of(attr, struct blk_mq_hw_ctx_sysfs_entry, attr);
87 	hctx = container_of(kobj, struct blk_mq_hw_ctx, kobj);
88 	q = hctx->queue;
89 
90 	if (!entry->show)
91 		return -EIO;
92 
93 	res = -ENOENT;
94 	mutex_lock(&q->sysfs_lock);
95 	if (!blk_queue_dying(q))
96 		res = entry->show(hctx, page);
97 	mutex_unlock(&q->sysfs_lock);
98 	return res;
99 }
100 
101 static ssize_t blk_mq_hw_sysfs_store(struct kobject *kobj,
102 				     struct attribute *attr, const char *page,
103 				     size_t length)
104 {
105 	struct blk_mq_hw_ctx_sysfs_entry *entry;
106 	struct blk_mq_hw_ctx *hctx;
107 	struct request_queue *q;
108 	ssize_t res;
109 
110 	entry = container_of(attr, struct blk_mq_hw_ctx_sysfs_entry, attr);
111 	hctx = container_of(kobj, struct blk_mq_hw_ctx, kobj);
112 	q = hctx->queue;
113 
114 	if (!entry->store)
115 		return -EIO;
116 
117 	res = -ENOENT;
118 	mutex_lock(&q->sysfs_lock);
119 	if (!blk_queue_dying(q))
120 		res = entry->store(hctx, page, length);
121 	mutex_unlock(&q->sysfs_lock);
122 	return res;
123 }
124 
125 static ssize_t blk_mq_sysfs_dispatched_show(struct blk_mq_ctx *ctx, char *page)
126 {
127 	return sprintf(page, "%lu %lu\n", ctx->rq_dispatched[1],
128 				ctx->rq_dispatched[0]);
129 }
130 
131 static ssize_t blk_mq_sysfs_merged_show(struct blk_mq_ctx *ctx, char *page)
132 {
133 	return sprintf(page, "%lu\n", ctx->rq_merged);
134 }
135 
136 static ssize_t blk_mq_sysfs_completed_show(struct blk_mq_ctx *ctx, char *page)
137 {
138 	return sprintf(page, "%lu %lu\n", ctx->rq_completed[1],
139 				ctx->rq_completed[0]);
140 }
141 
142 static ssize_t sysfs_list_show(char *page, struct list_head *list, char *msg)
143 {
144 	struct request *rq;
145 	int len = snprintf(page, PAGE_SIZE - 1, "%s:\n", msg);
146 
147 	list_for_each_entry(rq, list, queuelist) {
148 		const int rq_len = 2 * sizeof(rq) + 2;
149 
150 		/* if the output will be truncated */
151 		if (PAGE_SIZE - 1 < len + rq_len) {
152 			/* backspacing if it can't hold '\t...\n' */
153 			if (PAGE_SIZE - 1 < len + 5)
154 				len -= rq_len;
155 			len += snprintf(page + len, PAGE_SIZE - 1 - len,
156 					"\t...\n");
157 			break;
158 		}
159 		len += snprintf(page + len, PAGE_SIZE - 1 - len,
160 				"\t%p\n", rq);
161 	}
162 
163 	return len;
164 }
165 
166 static ssize_t blk_mq_sysfs_rq_list_show(struct blk_mq_ctx *ctx, char *page)
167 {
168 	ssize_t ret;
169 
170 	spin_lock(&ctx->lock);
171 	ret = sysfs_list_show(page, &ctx->rq_list, "CTX pending");
172 	spin_unlock(&ctx->lock);
173 
174 	return ret;
175 }
176 
177 static ssize_t blk_mq_hw_sysfs_poll_show(struct blk_mq_hw_ctx *hctx, char *page)
178 {
179 	return sprintf(page, "considered=%lu, invoked=%lu, success=%lu\n",
180 		       hctx->poll_considered, hctx->poll_invoked,
181 		       hctx->poll_success);
182 }
183 
184 static ssize_t blk_mq_hw_sysfs_poll_store(struct blk_mq_hw_ctx *hctx,
185 					  const char *page, size_t size)
186 {
187 	hctx->poll_considered = hctx->poll_invoked = hctx->poll_success = 0;
188 
189 	return size;
190 }
191 
192 static ssize_t blk_mq_hw_sysfs_queued_show(struct blk_mq_hw_ctx *hctx,
193 					   char *page)
194 {
195 	return sprintf(page, "%lu\n", hctx->queued);
196 }
197 
198 static ssize_t blk_mq_hw_sysfs_run_show(struct blk_mq_hw_ctx *hctx, char *page)
199 {
200 	return sprintf(page, "%lu\n", hctx->run);
201 }
202 
203 static ssize_t blk_mq_hw_sysfs_dispatched_show(struct blk_mq_hw_ctx *hctx,
204 					       char *page)
205 {
206 	char *start_page = page;
207 	int i;
208 
209 	page += sprintf(page, "%8u\t%lu\n", 0U, hctx->dispatched[0]);
210 
211 	for (i = 1; i < BLK_MQ_MAX_DISPATCH_ORDER - 1; i++) {
212 		unsigned int d = 1U << (i - 1);
213 
214 		page += sprintf(page, "%8u\t%lu\n", d, hctx->dispatched[i]);
215 	}
216 
217 	page += sprintf(page, "%8u+\t%lu\n", 1U << (i - 1),
218 						hctx->dispatched[i]);
219 	return page - start_page;
220 }
221 
222 static ssize_t blk_mq_hw_sysfs_rq_list_show(struct blk_mq_hw_ctx *hctx,
223 					    char *page)
224 {
225 	ssize_t ret;
226 
227 	spin_lock(&hctx->lock);
228 	ret = sysfs_list_show(page, &hctx->dispatch, "HCTX pending");
229 	spin_unlock(&hctx->lock);
230 
231 	return ret;
232 }
233 
234 static ssize_t blk_mq_hw_sysfs_tags_show(struct blk_mq_hw_ctx *hctx, char *page)
235 {
236 	return blk_mq_tag_sysfs_show(hctx->tags, page);
237 }
238 
239 static ssize_t blk_mq_hw_sysfs_active_show(struct blk_mq_hw_ctx *hctx, char *page)
240 {
241 	return sprintf(page, "%u\n", atomic_read(&hctx->nr_active));
242 }
243 
244 static ssize_t blk_mq_hw_sysfs_cpus_show(struct blk_mq_hw_ctx *hctx, char *page)
245 {
246 	unsigned int i, first = 1;
247 	ssize_t ret = 0;
248 
249 	for_each_cpu(i, hctx->cpumask) {
250 		if (first)
251 			ret += sprintf(ret + page, "%u", i);
252 		else
253 			ret += sprintf(ret + page, ", %u", i);
254 
255 		first = 0;
256 	}
257 
258 	ret += sprintf(ret + page, "\n");
259 	return ret;
260 }
261 
262 static void blk_mq_stat_clear(struct blk_mq_hw_ctx *hctx)
263 {
264 	struct blk_mq_ctx *ctx;
265 	unsigned int i;
266 
267 	hctx_for_each_ctx(hctx, ctx, i) {
268 		blk_stat_init(&ctx->stat[BLK_STAT_READ]);
269 		blk_stat_init(&ctx->stat[BLK_STAT_WRITE]);
270 	}
271 }
272 
273 static ssize_t blk_mq_hw_sysfs_stat_store(struct blk_mq_hw_ctx *hctx,
274 					  const char *page, size_t count)
275 {
276 	blk_mq_stat_clear(hctx);
277 	return count;
278 }
279 
280 static ssize_t print_stat(char *page, struct blk_rq_stat *stat, const char *pre)
281 {
282 	return sprintf(page, "%s samples=%llu, mean=%lld, min=%lld, max=%lld\n",
283 			pre, (long long) stat->nr_samples,
284 			(long long) stat->mean, (long long) stat->min,
285 			(long long) stat->max);
286 }
287 
288 static ssize_t blk_mq_hw_sysfs_stat_show(struct blk_mq_hw_ctx *hctx, char *page)
289 {
290 	struct blk_rq_stat stat[2];
291 	ssize_t ret;
292 
293 	blk_stat_init(&stat[BLK_STAT_READ]);
294 	blk_stat_init(&stat[BLK_STAT_WRITE]);
295 
296 	blk_hctx_stat_get(hctx, stat);
297 
298 	ret = print_stat(page, &stat[BLK_STAT_READ], "read :");
299 	ret += print_stat(page + ret, &stat[BLK_STAT_WRITE], "write:");
300 	return ret;
301 }
302 
303 static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_dispatched = {
304 	.attr = {.name = "dispatched", .mode = S_IRUGO },
305 	.show = blk_mq_sysfs_dispatched_show,
306 };
307 static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_merged = {
308 	.attr = {.name = "merged", .mode = S_IRUGO },
309 	.show = blk_mq_sysfs_merged_show,
310 };
311 static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_completed = {
312 	.attr = {.name = "completed", .mode = S_IRUGO },
313 	.show = blk_mq_sysfs_completed_show,
314 };
315 static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_rq_list = {
316 	.attr = {.name = "rq_list", .mode = S_IRUGO },
317 	.show = blk_mq_sysfs_rq_list_show,
318 };
319 
320 static struct attribute *default_ctx_attrs[] = {
321 	&blk_mq_sysfs_dispatched.attr,
322 	&blk_mq_sysfs_merged.attr,
323 	&blk_mq_sysfs_completed.attr,
324 	&blk_mq_sysfs_rq_list.attr,
325 	NULL,
326 };
327 
328 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_queued = {
329 	.attr = {.name = "queued", .mode = S_IRUGO },
330 	.show = blk_mq_hw_sysfs_queued_show,
331 };
332 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_run = {
333 	.attr = {.name = "run", .mode = S_IRUGO },
334 	.show = blk_mq_hw_sysfs_run_show,
335 };
336 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_dispatched = {
337 	.attr = {.name = "dispatched", .mode = S_IRUGO },
338 	.show = blk_mq_hw_sysfs_dispatched_show,
339 };
340 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_active = {
341 	.attr = {.name = "active", .mode = S_IRUGO },
342 	.show = blk_mq_hw_sysfs_active_show,
343 };
344 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_pending = {
345 	.attr = {.name = "pending", .mode = S_IRUGO },
346 	.show = blk_mq_hw_sysfs_rq_list_show,
347 };
348 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_tags = {
349 	.attr = {.name = "tags", .mode = S_IRUGO },
350 	.show = blk_mq_hw_sysfs_tags_show,
351 };
352 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_cpus = {
353 	.attr = {.name = "cpu_list", .mode = S_IRUGO },
354 	.show = blk_mq_hw_sysfs_cpus_show,
355 };
356 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_poll = {
357 	.attr = {.name = "io_poll", .mode = S_IWUSR | S_IRUGO },
358 	.show = blk_mq_hw_sysfs_poll_show,
359 	.store = blk_mq_hw_sysfs_poll_store,
360 };
361 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_stat = {
362 	.attr = {.name = "stats", .mode = S_IRUGO | S_IWUSR },
363 	.show = blk_mq_hw_sysfs_stat_show,
364 	.store = blk_mq_hw_sysfs_stat_store,
365 };
366 
367 static struct attribute *default_hw_ctx_attrs[] = {
368 	&blk_mq_hw_sysfs_queued.attr,
369 	&blk_mq_hw_sysfs_run.attr,
370 	&blk_mq_hw_sysfs_dispatched.attr,
371 	&blk_mq_hw_sysfs_pending.attr,
372 	&blk_mq_hw_sysfs_tags.attr,
373 	&blk_mq_hw_sysfs_cpus.attr,
374 	&blk_mq_hw_sysfs_active.attr,
375 	&blk_mq_hw_sysfs_poll.attr,
376 	&blk_mq_hw_sysfs_stat.attr,
377 	NULL,
378 };
379 
380 static const struct sysfs_ops blk_mq_sysfs_ops = {
381 	.show	= blk_mq_sysfs_show,
382 	.store	= blk_mq_sysfs_store,
383 };
384 
385 static const struct sysfs_ops blk_mq_hw_sysfs_ops = {
386 	.show	= blk_mq_hw_sysfs_show,
387 	.store	= blk_mq_hw_sysfs_store,
388 };
389 
390 static struct kobj_type blk_mq_ktype = {
391 	.sysfs_ops	= &blk_mq_sysfs_ops,
392 	.release	= blk_mq_sysfs_release,
393 };
394 
395 static struct kobj_type blk_mq_ctx_ktype = {
396 	.sysfs_ops	= &blk_mq_sysfs_ops,
397 	.default_attrs	= default_ctx_attrs,
398 	.release	= blk_mq_sysfs_release,
399 };
400 
401 static struct kobj_type blk_mq_hw_ktype = {
402 	.sysfs_ops	= &blk_mq_hw_sysfs_ops,
403 	.default_attrs	= default_hw_ctx_attrs,
404 	.release	= blk_mq_sysfs_release,
405 };
406 
407 static void blk_mq_unregister_hctx(struct blk_mq_hw_ctx *hctx)
408 {
409 	struct blk_mq_ctx *ctx;
410 	int i;
411 
412 	if (!hctx->nr_ctx)
413 		return;
414 
415 	hctx_for_each_ctx(hctx, ctx, i)
416 		kobject_del(&ctx->kobj);
417 
418 	kobject_del(&hctx->kobj);
419 }
420 
421 static int blk_mq_register_hctx(struct blk_mq_hw_ctx *hctx)
422 {
423 	struct request_queue *q = hctx->queue;
424 	struct blk_mq_ctx *ctx;
425 	int i, ret;
426 
427 	if (!hctx->nr_ctx)
428 		return 0;
429 
430 	ret = kobject_add(&hctx->kobj, &q->mq_kobj, "%u", hctx->queue_num);
431 	if (ret)
432 		return ret;
433 
434 	hctx_for_each_ctx(hctx, ctx, i) {
435 		ret = kobject_add(&ctx->kobj, &hctx->kobj, "cpu%u", ctx->cpu);
436 		if (ret)
437 			break;
438 	}
439 
440 	return ret;
441 }
442 
443 static void __blk_mq_unregister_dev(struct device *dev, struct request_queue *q)
444 {
445 	struct blk_mq_hw_ctx *hctx;
446 	struct blk_mq_ctx *ctx;
447 	int i, j;
448 
449 	queue_for_each_hw_ctx(q, hctx, i) {
450 		blk_mq_unregister_hctx(hctx);
451 
452 		hctx_for_each_ctx(hctx, ctx, j)
453 			kobject_put(&ctx->kobj);
454 
455 		kobject_put(&hctx->kobj);
456 	}
457 
458 	kobject_uevent(&q->mq_kobj, KOBJ_REMOVE);
459 	kobject_del(&q->mq_kobj);
460 	kobject_put(&q->mq_kobj);
461 
462 	kobject_put(&dev->kobj);
463 
464 	q->mq_sysfs_init_done = false;
465 }
466 
467 void blk_mq_unregister_dev(struct device *dev, struct request_queue *q)
468 {
469 	blk_mq_disable_hotplug();
470 	__blk_mq_unregister_dev(dev, q);
471 	blk_mq_enable_hotplug();
472 }
473 
474 void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx)
475 {
476 	kobject_init(&hctx->kobj, &blk_mq_hw_ktype);
477 }
478 
479 static void blk_mq_sysfs_init(struct request_queue *q)
480 {
481 	struct blk_mq_ctx *ctx;
482 	int cpu;
483 
484 	kobject_init(&q->mq_kobj, &blk_mq_ktype);
485 
486 	for_each_possible_cpu(cpu) {
487 		ctx = per_cpu_ptr(q->queue_ctx, cpu);
488 		kobject_init(&ctx->kobj, &blk_mq_ctx_ktype);
489 	}
490 }
491 
492 int blk_mq_register_dev(struct device *dev, struct request_queue *q)
493 {
494 	struct blk_mq_hw_ctx *hctx;
495 	int ret, i;
496 
497 	blk_mq_disable_hotplug();
498 
499 	blk_mq_sysfs_init(q);
500 
501 	ret = kobject_add(&q->mq_kobj, kobject_get(&dev->kobj), "%s", "mq");
502 	if (ret < 0)
503 		goto out;
504 
505 	kobject_uevent(&q->mq_kobj, KOBJ_ADD);
506 
507 	queue_for_each_hw_ctx(q, hctx, i) {
508 		ret = blk_mq_register_hctx(hctx);
509 		if (ret)
510 			break;
511 	}
512 
513 	if (ret)
514 		__blk_mq_unregister_dev(dev, q);
515 	else
516 		q->mq_sysfs_init_done = true;
517 out:
518 	blk_mq_enable_hotplug();
519 
520 	return ret;
521 }
522 EXPORT_SYMBOL_GPL(blk_mq_register_dev);
523 
524 void blk_mq_sysfs_unregister(struct request_queue *q)
525 {
526 	struct blk_mq_hw_ctx *hctx;
527 	int i;
528 
529 	if (!q->mq_sysfs_init_done)
530 		return;
531 
532 	queue_for_each_hw_ctx(q, hctx, i)
533 		blk_mq_unregister_hctx(hctx);
534 }
535 
536 int blk_mq_sysfs_register(struct request_queue *q)
537 {
538 	struct blk_mq_hw_ctx *hctx;
539 	int i, ret = 0;
540 
541 	if (!q->mq_sysfs_init_done)
542 		return ret;
543 
544 	queue_for_each_hw_ctx(q, hctx, i) {
545 		ret = blk_mq_register_hctx(hctx);
546 		if (ret)
547 			break;
548 	}
549 
550 	return ret;
551 }
552