xref: /openbmc/linux/block/blk-mq-sysfs.c (revision 3805e6a1) 
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, "invoked=%lu, success=%lu\n", hctx->poll_invoked, hctx->poll_success);
180 }
181 
182 static ssize_t blk_mq_hw_sysfs_queued_show(struct blk_mq_hw_ctx *hctx,
183 					   char *page)
184 {
185 	return sprintf(page, "%lu\n", hctx->queued);
186 }
187 
188 static ssize_t blk_mq_hw_sysfs_run_show(struct blk_mq_hw_ctx *hctx, char *page)
189 {
190 	return sprintf(page, "%lu\n", hctx->run);
191 }
192 
193 static ssize_t blk_mq_hw_sysfs_dispatched_show(struct blk_mq_hw_ctx *hctx,
194 					       char *page)
195 {
196 	char *start_page = page;
197 	int i;
198 
199 	page += sprintf(page, "%8u\t%lu\n", 0U, hctx->dispatched[0]);
200 
201 	for (i = 1; i < BLK_MQ_MAX_DISPATCH_ORDER; i++) {
202 		unsigned long d = 1U << (i - 1);
203 
204 		page += sprintf(page, "%8lu\t%lu\n", d, hctx->dispatched[i]);
205 	}
206 
207 	return page - start_page;
208 }
209 
210 static ssize_t blk_mq_hw_sysfs_rq_list_show(struct blk_mq_hw_ctx *hctx,
211 					    char *page)
212 {
213 	ssize_t ret;
214 
215 	spin_lock(&hctx->lock);
216 	ret = sysfs_list_show(page, &hctx->dispatch, "HCTX pending");
217 	spin_unlock(&hctx->lock);
218 
219 	return ret;
220 }
221 
222 static ssize_t blk_mq_hw_sysfs_tags_show(struct blk_mq_hw_ctx *hctx, char *page)
223 {
224 	return blk_mq_tag_sysfs_show(hctx->tags, page);
225 }
226 
227 static ssize_t blk_mq_hw_sysfs_active_show(struct blk_mq_hw_ctx *hctx, char *page)
228 {
229 	return sprintf(page, "%u\n", atomic_read(&hctx->nr_active));
230 }
231 
232 static ssize_t blk_mq_hw_sysfs_cpus_show(struct blk_mq_hw_ctx *hctx, char *page)
233 {
234 	unsigned int i, first = 1;
235 	ssize_t ret = 0;
236 
237 	for_each_cpu(i, hctx->cpumask) {
238 		if (first)
239 			ret += sprintf(ret + page, "%u", i);
240 		else
241 			ret += sprintf(ret + page, ", %u", i);
242 
243 		first = 0;
244 	}
245 
246 	ret += sprintf(ret + page, "\n");
247 	return ret;
248 }
249 
250 static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_dispatched = {
251 	.attr = {.name = "dispatched", .mode = S_IRUGO },
252 	.show = blk_mq_sysfs_dispatched_show,
253 };
254 static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_merged = {
255 	.attr = {.name = "merged", .mode = S_IRUGO },
256 	.show = blk_mq_sysfs_merged_show,
257 };
258 static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_completed = {
259 	.attr = {.name = "completed", .mode = S_IRUGO },
260 	.show = blk_mq_sysfs_completed_show,
261 };
262 static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_rq_list = {
263 	.attr = {.name = "rq_list", .mode = S_IRUGO },
264 	.show = blk_mq_sysfs_rq_list_show,
265 };
266 
267 static struct attribute *default_ctx_attrs[] = {
268 	&blk_mq_sysfs_dispatched.attr,
269 	&blk_mq_sysfs_merged.attr,
270 	&blk_mq_sysfs_completed.attr,
271 	&blk_mq_sysfs_rq_list.attr,
272 	NULL,
273 };
274 
275 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_queued = {
276 	.attr = {.name = "queued", .mode = S_IRUGO },
277 	.show = blk_mq_hw_sysfs_queued_show,
278 };
279 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_run = {
280 	.attr = {.name = "run", .mode = S_IRUGO },
281 	.show = blk_mq_hw_sysfs_run_show,
282 };
283 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_dispatched = {
284 	.attr = {.name = "dispatched", .mode = S_IRUGO },
285 	.show = blk_mq_hw_sysfs_dispatched_show,
286 };
287 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_active = {
288 	.attr = {.name = "active", .mode = S_IRUGO },
289 	.show = blk_mq_hw_sysfs_active_show,
290 };
291 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_pending = {
292 	.attr = {.name = "pending", .mode = S_IRUGO },
293 	.show = blk_mq_hw_sysfs_rq_list_show,
294 };
295 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_tags = {
296 	.attr = {.name = "tags", .mode = S_IRUGO },
297 	.show = blk_mq_hw_sysfs_tags_show,
298 };
299 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_cpus = {
300 	.attr = {.name = "cpu_list", .mode = S_IRUGO },
301 	.show = blk_mq_hw_sysfs_cpus_show,
302 };
303 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_poll = {
304 	.attr = {.name = "io_poll", .mode = S_IRUGO },
305 	.show = blk_mq_hw_sysfs_poll_show,
306 };
307 
308 static struct attribute *default_hw_ctx_attrs[] = {
309 	&blk_mq_hw_sysfs_queued.attr,
310 	&blk_mq_hw_sysfs_run.attr,
311 	&blk_mq_hw_sysfs_dispatched.attr,
312 	&blk_mq_hw_sysfs_pending.attr,
313 	&blk_mq_hw_sysfs_tags.attr,
314 	&blk_mq_hw_sysfs_cpus.attr,
315 	&blk_mq_hw_sysfs_active.attr,
316 	&blk_mq_hw_sysfs_poll.attr,
317 	NULL,
318 };
319 
320 static const struct sysfs_ops blk_mq_sysfs_ops = {
321 	.show	= blk_mq_sysfs_show,
322 	.store	= blk_mq_sysfs_store,
323 };
324 
325 static const struct sysfs_ops blk_mq_hw_sysfs_ops = {
326 	.show	= blk_mq_hw_sysfs_show,
327 	.store	= blk_mq_hw_sysfs_store,
328 };
329 
330 static struct kobj_type blk_mq_ktype = {
331 	.sysfs_ops	= &blk_mq_sysfs_ops,
332 	.release	= blk_mq_sysfs_release,
333 };
334 
335 static struct kobj_type blk_mq_ctx_ktype = {
336 	.sysfs_ops	= &blk_mq_sysfs_ops,
337 	.default_attrs	= default_ctx_attrs,
338 	.release	= blk_mq_sysfs_release,
339 };
340 
341 static struct kobj_type blk_mq_hw_ktype = {
342 	.sysfs_ops	= &blk_mq_hw_sysfs_ops,
343 	.default_attrs	= default_hw_ctx_attrs,
344 	.release	= blk_mq_sysfs_release,
345 };
346 
347 static void blk_mq_unregister_hctx(struct blk_mq_hw_ctx *hctx)
348 {
349 	struct blk_mq_ctx *ctx;
350 	int i;
351 
352 	if (!hctx->nr_ctx)
353 		return;
354 
355 	hctx_for_each_ctx(hctx, ctx, i)
356 		kobject_del(&ctx->kobj);
357 
358 	kobject_del(&hctx->kobj);
359 }
360 
361 static int blk_mq_register_hctx(struct blk_mq_hw_ctx *hctx)
362 {
363 	struct request_queue *q = hctx->queue;
364 	struct blk_mq_ctx *ctx;
365 	int i, ret;
366 
367 	if (!hctx->nr_ctx)
368 		return 0;
369 
370 	ret = kobject_add(&hctx->kobj, &q->mq_kobj, "%u", hctx->queue_num);
371 	if (ret)
372 		return ret;
373 
374 	hctx_for_each_ctx(hctx, ctx, i) {
375 		ret = kobject_add(&ctx->kobj, &hctx->kobj, "cpu%u", ctx->cpu);
376 		if (ret)
377 			break;
378 	}
379 
380 	return ret;
381 }
382 
383 void blk_mq_unregister_disk(struct gendisk *disk)
384 {
385 	struct request_queue *q = disk->queue;
386 	struct blk_mq_hw_ctx *hctx;
387 	struct blk_mq_ctx *ctx;
388 	int i, j;
389 
390 	blk_mq_disable_hotplug();
391 
392 	queue_for_each_hw_ctx(q, hctx, i) {
393 		blk_mq_unregister_hctx(hctx);
394 
395 		hctx_for_each_ctx(hctx, ctx, j)
396 			kobject_put(&ctx->kobj);
397 
398 		kobject_put(&hctx->kobj);
399 	}
400 
401 	kobject_uevent(&q->mq_kobj, KOBJ_REMOVE);
402 	kobject_del(&q->mq_kobj);
403 	kobject_put(&q->mq_kobj);
404 
405 	kobject_put(&disk_to_dev(disk)->kobj);
406 
407 	q->mq_sysfs_init_done = false;
408 	blk_mq_enable_hotplug();
409 }
410 
411 void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx)
412 {
413 	kobject_init(&hctx->kobj, &blk_mq_hw_ktype);
414 }
415 
416 static void blk_mq_sysfs_init(struct request_queue *q)
417 {
418 	struct blk_mq_ctx *ctx;
419 	int cpu;
420 
421 	kobject_init(&q->mq_kobj, &blk_mq_ktype);
422 
423 	for_each_possible_cpu(cpu) {
424 		ctx = per_cpu_ptr(q->queue_ctx, cpu);
425 		kobject_init(&ctx->kobj, &blk_mq_ctx_ktype);
426 	}
427 }
428 
429 int blk_mq_register_disk(struct gendisk *disk)
430 {
431 	struct device *dev = disk_to_dev(disk);
432 	struct request_queue *q = disk->queue;
433 	struct blk_mq_hw_ctx *hctx;
434 	int ret, i;
435 
436 	blk_mq_disable_hotplug();
437 
438 	blk_mq_sysfs_init(q);
439 
440 	ret = kobject_add(&q->mq_kobj, kobject_get(&dev->kobj), "%s", "mq");
441 	if (ret < 0)
442 		goto out;
443 
444 	kobject_uevent(&q->mq_kobj, KOBJ_ADD);
445 
446 	queue_for_each_hw_ctx(q, hctx, i) {
447 		ret = blk_mq_register_hctx(hctx);
448 		if (ret)
449 			break;
450 	}
451 
452 	if (ret)
453 		blk_mq_unregister_disk(disk);
454 	else
455 		q->mq_sysfs_init_done = true;
456 out:
457 	blk_mq_enable_hotplug();
458 
459 	return ret;
460 }
461 EXPORT_SYMBOL_GPL(blk_mq_register_disk);
462 
463 void blk_mq_sysfs_unregister(struct request_queue *q)
464 {
465 	struct blk_mq_hw_ctx *hctx;
466 	int i;
467 
468 	if (!q->mq_sysfs_init_done)
469 		return;
470 
471 	queue_for_each_hw_ctx(q, hctx, i)
472 		blk_mq_unregister_hctx(hctx);
473 }
474 
475 int blk_mq_sysfs_register(struct request_queue *q)
476 {
477 	struct blk_mq_hw_ctx *hctx;
478 	int i, ret = 0;
479 
480 	if (!q->mq_sysfs_init_done)
481 		return ret;
482 
483 	queue_for_each_hw_ctx(q, hctx, i) {
484 		ret = blk_mq_register_hctx(hctx);
485 		if (ret)
486 			break;
487 	}
488 
489 	return ret;
490 }
491