aboutsummaryrefslogtreecommitdiff
path: root/block/blk-mq-sysfs.c
blob: 7b52e7657b2d1b2f3cb207b616da4365600def59 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/backing-dev.h>
#include <linux/bio.h>
#include <linux/blkdev.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <linux/smp.h>

#include <linux/blk-mq.h>
#include "blk.h"
#include "blk-mq.h"
#include "blk-mq-tag.h"

static void blk_mq_sysfs_release(struct kobject *kobj)
{
	struct blk_mq_ctxs *ctxs = container_of(kobj, struct blk_mq_ctxs, kobj);

	free_percpu(ctxs->queue_ctx);
	kfree(ctxs);
}

static void blk_mq_ctx_sysfs_release(struct kobject *kobj)
{
	struct blk_mq_ctx *ctx = container_of(kobj, struct blk_mq_ctx, kobj);

	/* ctx->ctxs won't be released until all ctx are freed */
	kobject_put(&ctx->ctxs->kobj);
}

static void blk_mq_hw_sysfs_release(struct kobject *kobj)
{
	struct blk_mq_hw_ctx *hctx = container_of(kobj, struct blk_mq_hw_ctx,
						  kobj);

	if (hctx->flags & BLK_MQ_F_BLOCKING)
		cleanup_srcu_struct(hctx->srcu);
	blk_free_flush_queue(hctx->fq);
	sbitmap_free(&hctx->ctx_map);
	free_cpumask_var(hctx->cpumask);
	kfree(hctx->ctxs);
	kfree(hctx);
}

struct blk_mq_ctx_sysfs_entry {
	struct attribute attr;
	ssize_t (*show)(struct blk_mq_ctx *, char *);
	ssize_t (*store)(struct blk_mq_ctx *, const char *, size_t);
};

struct blk_mq_hw_ctx_sysfs_entry {
	struct attribute attr;
	ssize_t (*show)(struct blk_mq_hw_ctx *, char *);
	ssize_t (*store)(struct blk_mq_hw_ctx *, const char *, size_t);
};

static ssize_t blk_mq_sysfs_show(struct kobject *kobj, struct attribute *attr,
				 char *page)
{
	struct blk_mq_ctx_sysfs_entry *entry;
	struct blk_mq_ctx *ctx;
	struct request_queue *q;
	ssize_t res;

	entry = container_of(attr, struct blk_mq_ctx_sysfs_entry, attr);
	ctx = container_of(kobj, struct blk_mq_ctx, kobj);
	q = ctx->queue;

	if (!entry->show)
		return -EIO;

	mutex_lock(&q->sysfs_lock);
	res = entry->show(ctx, page);
	mutex_unlock(&q->sysfs_lock);
	return res;
}

static ssize_t blk_mq_sysfs_store(struct kobject *kobj, struct attribute *attr,
				  const char *page, size_t length)
{
	struct blk_mq_ctx_sysfs_entry *entry;
	struct blk_mq_ctx *ctx;
	struct request_queue *q;
	ssize_t res;

	entry = container_of(attr, struct blk_mq_ctx_sysfs_entry, attr);
	ctx = container_of(kobj, struct blk_mq_ctx, kobj);
	q = ctx->queue;

	if (!entry->store)
		return -EIO;

	mutex_lock(&q->sysfs_lock);
	res = entry->store(ctx, page, length);
	mutex_unlock(&q->sysfs_lock);
	return res;
}

static ssize_t blk_mq_hw_sysfs_show(struct kobject *kobj,
				    struct attribute *attr, char *page)
{
	struct blk_mq_hw_ctx_sysfs_entry *entry;
	struct blk_mq_hw_ctx *hctx;
	struct request_queue *q;
	ssize_t res;

	entry = container_of(attr, struct blk_mq_hw_ctx_sysfs_entry, attr);
	hctx = container_of(kobj, struct blk_mq_hw_ctx, kobj);
	q = hctx->queue;

	if (!entry->show)
		return -EIO;

	mutex_lock(&q->sysfs_lock);
	res = entry->show(hctx, page);
	mutex_unlock(&q->sysfs_lock);
	return res;
}

static ssize_t blk_mq_hw_sysfs_store(struct kobject *kobj,
				     struct attribute *attr, const char *page,
				     size_t length)
{
	struct blk_mq_hw_ctx_sysfs_entry *entry;
	struct blk_mq_hw_ctx *hctx;
	struct request_queue *q;
	ssize_t res;

	entry = container_of(attr, struct blk_mq_hw_ctx_sysfs_entry, attr);
	hctx = container_of(kobj, struct blk_mq_hw_ctx, kobj);
	q = hctx->queue;

	if (!entry->store)
		return -EIO;

	mutex_lock(&q->sysfs_lock);
	res = entry->store(hctx, page, length);
	mutex_unlock(&q->sysfs_lock);
	return res;
}

static ssize_t blk_mq_hw_sysfs_nr_tags_show(struct blk_mq_hw_ctx *hctx,
					    char *page)
{
	return sprintf(page, "%u\n", hctx->tags->nr_tags);
}

static ssize_t blk_mq_hw_sysfs_nr_reserved_tags_show(struct blk_mq_hw_ctx *hctx,
						     char *page)
{
	return sprintf(page, "%u\n", hctx->tags->nr_reserved_tags);
}

static ssize_t blk_mq_hw_sysfs_cpus_show(struct blk_mq_hw_ctx *hctx, char *page)
{
	const size_t size = PAGE_SIZE - 1;
	unsigned int i, first = 1;
	int ret = 0, pos = 0;

	for_each_cpu(i, hctx->cpumask) {
		if (first)
			ret = snprintf(pos + page, size - pos, "%u", i);
		else
			ret = snprintf(pos + page, size - pos, ", %u", i);

		if (ret >= size - pos)
			break;

		first = 0;
		pos += ret;
	}

	ret = snprintf(pos + page, size + 1 - pos, "\n");
	return pos + ret;
}

static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_nr_tags = {
	.attr = {.name = "nr_tags", .mode = 0444 },
	.show = blk_mq_hw_sysfs_nr_tags_show,
};
static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_nr_reserved_tags = {
	.attr = {.name = "nr_reserved_tags", .mode = 0444 },
	.show = blk_mq_hw_sysfs_nr_reserved_tags_show,
};
static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_cpus = {
	.attr = {.name = "cpu_list", .mode = 0444 },
	.show = blk_mq_hw_sysfs_cpus_show,
};

static struct attribute *default_hw_ctx_attrs[] = {
	&blk_mq_hw_sysfs_nr_tags.attr,
	&blk_mq_hw_sysfs_nr_reserved_tags.attr,
	&blk_mq_hw_sysfs_cpus.attr,
	NULL,
};
ATTRIBUTE_GROUPS(default_hw_ctx);

static const struct sysfs_ops blk_mq_sysfs_ops = {
	.show	= blk_mq_sysfs_show,
	.store	= blk_mq_sysfs_store,
};

static const struct sysfs_ops blk_mq_hw_sysfs_ops = {
	.show	= blk_mq_hw_sysfs_show,
	.store	= blk_mq_hw_sysfs_store,
};

static struct kobj_type blk_mq_ktype = {
	.sysfs_ops	= &blk_mq_sysfs_ops,
	.release	= blk_mq_sysfs_release,
};

static struct kobj_type blk_mq_ctx_ktype = {
	.sysfs_ops	= &blk_mq_sysfs_ops,
	.release	= blk_mq_ctx_sysfs_release,
};

static struct kobj_type blk_mq_hw_ktype = {
	.sysfs_ops	= &blk_mq_hw_sysfs_ops,
	.default_groups = default_hw_ctx_groups,
	.release	= blk_mq_hw_sysfs_release,
};

static void blk_mq_unregister_hctx(struct blk_mq_hw_ctx *hctx)
{
	struct blk_mq_ctx *ctx;
	int i;

	if (!hctx->nr_ctx)
		return;

	hctx_for_each_ctx(hctx, ctx, i)
		kobject_del(&ctx->kobj);

	kobject_del(&hctx->kobj);
}

static int blk_mq_register_hctx(struct blk_mq_hw_ctx *hctx)
{
	struct request_queue *q = hctx->queue;
	struct blk_mq_ctx *ctx;
	int i, ret;

	if (!hctx->nr_ctx)
		return 0;

	ret = kobject_add(&hctx->kobj, q->mq_kobj, "%u", hctx->queue_num);
	if (ret)
		return ret;

	hctx_for_each_ctx(hctx, ctx, i) {
		ret = kobject_add(&ctx->kobj, &hctx->kobj, "cpu%u", ctx->cpu);
		if (ret)
			break;
	}

	return ret;
}

void blk_mq_unregister_dev(struct device *dev, struct request_queue *q)
{
	struct blk_mq_hw_ctx *hctx;
	int i;

	lockdep_assert_held(&q->sysfs_dir_lock);

	queue_for_each_hw_ctx(q, hctx, i)
		blk_mq_unregister_hctx(hctx);

	kobject_uevent(q->mq_kobj, KOBJ_REMOVE);
	kobject_del(q->mq_kobj);
	kobject_put(&dev->kobj);

	q->mq_sysfs_init_done = false;
}

void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx)
{
	kobject_init(&hctx->kobj, &blk_mq_hw_ktype);
}

void blk_mq_sysfs_deinit(struct request_queue *q)
{
	struct blk_mq_ctx *ctx;
	int cpu;

	for_each_possible_cpu(cpu) {
		ctx = per_cpu_ptr(q->queue_ctx, cpu);
		kobject_put(&ctx->kobj);
	}
	kobject_put(q->mq_kobj);
}

void blk_mq_sysfs_init(struct request_queue *q)
{
	struct blk_mq_ctx *ctx;
	int cpu;

	kobject_init(q->mq_kobj, &blk_mq_ktype);

	for_each_possible_cpu(cpu) {
		ctx = per_cpu_ptr(q->queue_ctx, cpu);

		kobject_get(q->mq_kobj);
		kobject_init(&ctx->kobj, &blk_mq_ctx_ktype);
	}
}

int __blk_mq_register_dev(struct device *dev, struct request_queue *q)
{
	struct blk_mq_hw_ctx *hctx;
	int ret, i;

	WARN_ON_ONCE(!q->kobj.parent);
	lockdep_assert_held(&q->sysfs_dir_lock);

	ret = kobject_add(q->mq_kobj, kobject_get(&dev->kobj), "%s", "mq");
	if (ret < 0)
		goto out;

	kobject_uevent(q->mq_kobj, KOBJ_ADD);

	queue_for_each_hw_ctx(q, hctx, i) {
		ret = blk_mq_register_hctx(hctx);
		if (ret)
			goto unreg;
	}

	q->mq_sysfs_init_done = true;

out:
	return ret;

unreg:
	while (--i >= 0)
		blk_mq_unregister_hctx(q->queue_hw_ctx[i]);

	kobject_uevent(q->mq_kobj, KOBJ_REMOVE);
	kobject_del(q->mq_kobj);
	kobject_put(&dev->kobj);
	return ret;
}

void blk_mq_sysfs_unregister(struct request_queue *q)
{
	struct blk_mq_hw_ctx *hctx;
	int i;

	mutex_lock(&q->sysfs_dir_lock);
	if (!q->mq_sysfs_init_done)
		goto unlock;

	queue_for_each_hw_ctx(q, hctx, i)
		blk_mq_unregister_hctx(hctx);

unlock:
	mutex_unlock(&q->sysfs_dir_lock);
}

int blk_mq_sysfs_register(struct request_queue *q)
{
	struct blk_mq_hw_ctx *hctx;
	int i, ret = 0;

	mutex_lock(&q->sysfs_dir_lock);
	if (!q->mq_sysfs_init_done)
		goto unlock;

	queue_for_each_hw_ctx(q, hctx, i) {
		ret = blk_mq_register_hctx(hctx);
		if (ret)
			break;
	}

unlock:
	mutex_unlock(&q->sysfs_dir_lock);

	return ret;
}