xref: /openbmc/linux/block/blk-mq-sysfs.c (revision 552b8b36) 
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_queued_show(struct blk_mq_hw_ctx *hctx,
178 					   char *page)
179 {
180 	return sprintf(page, "%lu\n", hctx->queued);
181 }
182 
183 static ssize_t blk_mq_hw_sysfs_run_show(struct blk_mq_hw_ctx *hctx, char *page)
184 {
185 	return sprintf(page, "%lu\n", hctx->run);
186 }
187 
188 static ssize_t blk_mq_hw_sysfs_dispatched_show(struct blk_mq_hw_ctx *hctx,
189 					       char *page)
190 {
191 	char *start_page = page;
192 	int i;
193 
194 	page += sprintf(page, "%8u\t%lu\n", 0U, hctx->dispatched[0]);
195 
196 	for (i = 1; i < BLK_MQ_MAX_DISPATCH_ORDER; i++) {
197 		unsigned long d = 1U << (i - 1);
198 
199 		page += sprintf(page, "%8lu\t%lu\n", d, hctx->dispatched[i]);
200 	}
201 
202 	return page - start_page;
203 }
204 
205 static ssize_t blk_mq_hw_sysfs_rq_list_show(struct blk_mq_hw_ctx *hctx,
206 					    char *page)
207 {
208 	ssize_t ret;
209 
210 	spin_lock(&hctx->lock);
211 	ret = sysfs_list_show(page, &hctx->dispatch, "HCTX pending");
212 	spin_unlock(&hctx->lock);
213 
214 	return ret;
215 }
216 
217 static ssize_t blk_mq_hw_sysfs_tags_show(struct blk_mq_hw_ctx *hctx, char *page)
218 {
219 	return blk_mq_tag_sysfs_show(hctx->tags, page);
220 }
221 
222 static ssize_t blk_mq_hw_sysfs_active_show(struct blk_mq_hw_ctx *hctx, char *page)
223 {
224 	return sprintf(page, "%u\n", atomic_read(&hctx->nr_active));
225 }
226 
227 static ssize_t blk_mq_hw_sysfs_cpus_show(struct blk_mq_hw_ctx *hctx, char *page)
228 {
229 	unsigned int i, first = 1;
230 	ssize_t ret = 0;
231 
232 	for_each_cpu(i, hctx->cpumask) {
233 		if (first)
234 			ret += sprintf(ret + page, "%u", i);
235 		else
236 			ret += sprintf(ret + page, ", %u", i);
237 
238 		first = 0;
239 	}
240 
241 	ret += sprintf(ret + page, "\n");
242 	return ret;
243 }
244 
245 static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_dispatched = {
246 	.attr = {.name = "dispatched", .mode = S_IRUGO },
247 	.show = blk_mq_sysfs_dispatched_show,
248 };
249 static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_merged = {
250 	.attr = {.name = "merged", .mode = S_IRUGO },
251 	.show = blk_mq_sysfs_merged_show,
252 };
253 static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_completed = {
254 	.attr = {.name = "completed", .mode = S_IRUGO },
255 	.show = blk_mq_sysfs_completed_show,
256 };
257 static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_rq_list = {
258 	.attr = {.name = "rq_list", .mode = S_IRUGO },
259 	.show = blk_mq_sysfs_rq_list_show,
260 };
261 
262 static struct attribute *default_ctx_attrs[] = {
263 	&blk_mq_sysfs_dispatched.attr,
264 	&blk_mq_sysfs_merged.attr,
265 	&blk_mq_sysfs_completed.attr,
266 	&blk_mq_sysfs_rq_list.attr,
267 	NULL,
268 };
269 
270 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_queued = {
271 	.attr = {.name = "queued", .mode = S_IRUGO },
272 	.show = blk_mq_hw_sysfs_queued_show,
273 };
274 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_run = {
275 	.attr = {.name = "run", .mode = S_IRUGO },
276 	.show = blk_mq_hw_sysfs_run_show,
277 };
278 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_dispatched = {
279 	.attr = {.name = "dispatched", .mode = S_IRUGO },
280 	.show = blk_mq_hw_sysfs_dispatched_show,
281 };
282 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_active = {
283 	.attr = {.name = "active", .mode = S_IRUGO },
284 	.show = blk_mq_hw_sysfs_active_show,
285 };
286 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_pending = {
287 	.attr = {.name = "pending", .mode = S_IRUGO },
288 	.show = blk_mq_hw_sysfs_rq_list_show,
289 };
290 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_tags = {
291 	.attr = {.name = "tags", .mode = S_IRUGO },
292 	.show = blk_mq_hw_sysfs_tags_show,
293 };
294 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_cpus = {
295 	.attr = {.name = "cpu_list", .mode = S_IRUGO },
296 	.show = blk_mq_hw_sysfs_cpus_show,
297 };
298 
299 static struct attribute *default_hw_ctx_attrs[] = {
300 	&blk_mq_hw_sysfs_queued.attr,
301 	&blk_mq_hw_sysfs_run.attr,
302 	&blk_mq_hw_sysfs_dispatched.attr,
303 	&blk_mq_hw_sysfs_pending.attr,
304 	&blk_mq_hw_sysfs_tags.attr,
305 	&blk_mq_hw_sysfs_cpus.attr,
306 	&blk_mq_hw_sysfs_active.attr,
307 	NULL,
308 };
309 
310 static const struct sysfs_ops blk_mq_sysfs_ops = {
311 	.show	= blk_mq_sysfs_show,
312 	.store	= blk_mq_sysfs_store,
313 };
314 
315 static const struct sysfs_ops blk_mq_hw_sysfs_ops = {
316 	.show	= blk_mq_hw_sysfs_show,
317 	.store	= blk_mq_hw_sysfs_store,
318 };
319 
320 static struct kobj_type blk_mq_ktype = {
321 	.sysfs_ops	= &blk_mq_sysfs_ops,
322 	.release	= blk_mq_sysfs_release,
323 };
324 
325 static struct kobj_type blk_mq_ctx_ktype = {
326 	.sysfs_ops	= &blk_mq_sysfs_ops,
327 	.default_attrs	= default_ctx_attrs,
328 	.release	= blk_mq_sysfs_release,
329 };
330 
331 static struct kobj_type blk_mq_hw_ktype = {
332 	.sysfs_ops	= &blk_mq_hw_sysfs_ops,
333 	.default_attrs	= default_hw_ctx_attrs,
334 	.release	= blk_mq_sysfs_release,
335 };
336 
337 static void blk_mq_unregister_hctx(struct blk_mq_hw_ctx *hctx)
338 {
339 	struct blk_mq_ctx *ctx;
340 	int i;
341 
342 	if (!hctx->nr_ctx)
343 		return;
344 
345 	hctx_for_each_ctx(hctx, ctx, i)
346 		kobject_del(&ctx->kobj);
347 
348 	kobject_del(&hctx->kobj);
349 }
350 
351 static int blk_mq_register_hctx(struct blk_mq_hw_ctx *hctx)
352 {
353 	struct request_queue *q = hctx->queue;
354 	struct blk_mq_ctx *ctx;
355 	int i, ret;
356 
357 	if (!hctx->nr_ctx)
358 		return 0;
359 
360 	ret = kobject_add(&hctx->kobj, &q->mq_kobj, "%u", hctx->queue_num);
361 	if (ret)
362 		return ret;
363 
364 	hctx_for_each_ctx(hctx, ctx, i) {
365 		ret = kobject_add(&ctx->kobj, &hctx->kobj, "cpu%u", ctx->cpu);
366 		if (ret)
367 			break;
368 	}
369 
370 	return ret;
371 }
372 
373 void blk_mq_unregister_disk(struct gendisk *disk)
374 {
375 	struct request_queue *q = disk->queue;
376 	struct blk_mq_hw_ctx *hctx;
377 	struct blk_mq_ctx *ctx;
378 	int i, j;
379 
380 	blk_mq_disable_hotplug();
381 
382 	queue_for_each_hw_ctx(q, hctx, i) {
383 		blk_mq_unregister_hctx(hctx);
384 
385 		hctx_for_each_ctx(hctx, ctx, j)
386 			kobject_put(&ctx->kobj);
387 
388 		kobject_put(&hctx->kobj);
389 	}
390 
391 	kobject_uevent(&q->mq_kobj, KOBJ_REMOVE);
392 	kobject_del(&q->mq_kobj);
393 	kobject_put(&q->mq_kobj);
394 
395 	kobject_put(&disk_to_dev(disk)->kobj);
396 
397 	q->mq_sysfs_init_done = false;
398 	blk_mq_enable_hotplug();
399 }
400 
401 static void blk_mq_sysfs_init(struct request_queue *q)
402 {
403 	struct blk_mq_hw_ctx *hctx;
404 	struct blk_mq_ctx *ctx;
405 	int i;
406 
407 	kobject_init(&q->mq_kobj, &blk_mq_ktype);
408 
409 	queue_for_each_hw_ctx(q, hctx, i)
410 		kobject_init(&hctx->kobj, &blk_mq_hw_ktype);
411 
412 	queue_for_each_ctx(q, ctx, i)
413 		kobject_init(&ctx->kobj, &blk_mq_ctx_ktype);
414 }
415 
416 /* see blk_register_queue() */
417 void blk_mq_finish_init(struct request_queue *q)
418 {
419 	percpu_ref_switch_to_percpu(&q->mq_usage_counter);
420 }
421 
422 int blk_mq_register_disk(struct gendisk *disk)
423 {
424 	struct device *dev = disk_to_dev(disk);
425 	struct request_queue *q = disk->queue;
426 	struct blk_mq_hw_ctx *hctx;
427 	int ret, i;
428 
429 	blk_mq_disable_hotplug();
430 
431 	blk_mq_sysfs_init(q);
432 
433 	ret = kobject_add(&q->mq_kobj, kobject_get(&dev->kobj), "%s", "mq");
434 	if (ret < 0)
435 		goto out;
436 
437 	kobject_uevent(&q->mq_kobj, KOBJ_ADD);
438 
439 	queue_for_each_hw_ctx(q, hctx, i) {
440 		ret = blk_mq_register_hctx(hctx);
441 		if (ret)
442 			break;
443 	}
444 
445 	if (ret)
446 		blk_mq_unregister_disk(disk);
447 	else
448 		q->mq_sysfs_init_done = true;
449 out:
450 	blk_mq_enable_hotplug();
451 
452 	return ret;
453 }
454 EXPORT_SYMBOL_GPL(blk_mq_register_disk);
455 
456 void blk_mq_sysfs_unregister(struct request_queue *q)
457 {
458 	struct blk_mq_hw_ctx *hctx;
459 	int i;
460 
461 	if (!q->mq_sysfs_init_done)
462 		return;
463 
464 	queue_for_each_hw_ctx(q, hctx, i)
465 		blk_mq_unregister_hctx(hctx);
466 }
467 
468 int blk_mq_sysfs_register(struct request_queue *q)
469 {
470 	struct blk_mq_hw_ctx *hctx;
471 	int i, ret = 0;
472 
473 	if (!q->mq_sysfs_init_done)
474 		return ret;
475 
476 	queue_for_each_hw_ctx(q, hctx, i) {
477 		ret = blk_mq_register_hctx(hctx);
478 		if (ret)
479 			break;
480 	}
481 
482 	return ret;
483 }
484