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
16static void blk_mq_sysfs_release(struct kobject *kobj)
17{
18 struct blk_mq_ctxs *ctxs = container_of(kobj, struct blk_mq_ctxs, kobj);
19
20 free_percpu(ctxs->queue_ctx);
21 kfree(ctxs);
22}
23
24static void blk_mq_ctx_sysfs_release(struct kobject *kobj)
25{
26 struct blk_mq_ctx *ctx = container_of(kobj, struct blk_mq_ctx, kobj);
27
28 /* ctx->ctxs won't be released until all ctx are freed */
29 kobject_put(&ctx->ctxs->kobj);
30}
31
32static void blk_mq_hw_sysfs_release(struct kobject *kobj)
33{
34 struct blk_mq_hw_ctx *hctx = container_of(kobj, struct blk_mq_hw_ctx,
35 kobj);
36 free_cpumask_var(hctx->cpumask);
37 kfree(hctx->ctxs);
38 kfree(hctx);
39}
40
41struct blk_mq_ctx_sysfs_entry {
42 struct attribute attr;
43 ssize_t (*show)(struct blk_mq_ctx *, char *);
44 ssize_t (*store)(struct blk_mq_ctx *, const char *, size_t);
45};
46
47struct blk_mq_hw_ctx_sysfs_entry {
48 struct attribute attr;
49 ssize_t (*show)(struct blk_mq_hw_ctx *, char *);
50 ssize_t (*store)(struct blk_mq_hw_ctx *, const char *, size_t);
51};
52
53static ssize_t blk_mq_sysfs_show(struct kobject *kobj, struct attribute *attr,
54 char *page)
55{
56 struct blk_mq_ctx_sysfs_entry *entry;
57 struct blk_mq_ctx *ctx;
58 struct request_queue *q;
59 ssize_t res;
60
61 entry = container_of(attr, struct blk_mq_ctx_sysfs_entry, attr);
62 ctx = container_of(kobj, struct blk_mq_ctx, kobj);
63 q = ctx->queue;
64
65 if (!entry->show)
66 return -EIO;
67
68 res = -ENOENT;
69 mutex_lock(&q->sysfs_lock);
70 if (!blk_queue_dying(q))
71 res = entry->show(ctx, page);
72 mutex_unlock(&q->sysfs_lock);
73 return res;
74}
75
76static ssize_t blk_mq_sysfs_store(struct kobject *kobj, struct attribute *attr,
77 const char *page, size_t length)
78{
79 struct blk_mq_ctx_sysfs_entry *entry;
80 struct blk_mq_ctx *ctx;
81 struct request_queue *q;
82 ssize_t res;
83
84 entry = container_of(attr, struct blk_mq_ctx_sysfs_entry, attr);
85 ctx = container_of(kobj, struct blk_mq_ctx, kobj);
86 q = ctx->queue;
87
88 if (!entry->store)
89 return -EIO;
90
91 res = -ENOENT;
92 mutex_lock(&q->sysfs_lock);
93 if (!blk_queue_dying(q))
94 res = entry->store(ctx, page, length);
95 mutex_unlock(&q->sysfs_lock);
96 return res;
97}
98
99static ssize_t blk_mq_hw_sysfs_show(struct kobject *kobj,
100 struct attribute *attr, char *page)
101{
102 struct blk_mq_hw_ctx_sysfs_entry *entry;
103 struct blk_mq_hw_ctx *hctx;
104 struct request_queue *q;
105 ssize_t res;
106
107 entry = container_of(attr, struct blk_mq_hw_ctx_sysfs_entry, attr);
108 hctx = container_of(kobj, struct blk_mq_hw_ctx, kobj);
109 q = hctx->queue;
110
111 if (!entry->show)
112 return -EIO;
113
114 res = -ENOENT;
115 mutex_lock(&q->sysfs_lock);
116 if (!blk_queue_dying(q))
117 res = entry->show(hctx, page);
118 mutex_unlock(&q->sysfs_lock);
119 return res;
120}
121
122static ssize_t blk_mq_hw_sysfs_store(struct kobject *kobj,
123 struct attribute *attr, const char *page,
124 size_t length)
125{
126 struct blk_mq_hw_ctx_sysfs_entry *entry;
127 struct blk_mq_hw_ctx *hctx;
128 struct request_queue *q;
129 ssize_t res;
130
131 entry = container_of(attr, struct blk_mq_hw_ctx_sysfs_entry, attr);
132 hctx = container_of(kobj, struct blk_mq_hw_ctx, kobj);
133 q = hctx->queue;
134
135 if (!entry->store)
136 return -EIO;
137
138 res = -ENOENT;
139 mutex_lock(&q->sysfs_lock);
140 if (!blk_queue_dying(q))
141 res = entry->store(hctx, page, length);
142 mutex_unlock(&q->sysfs_lock);
143 return res;
144}
145
146static ssize_t blk_mq_hw_sysfs_nr_tags_show(struct blk_mq_hw_ctx *hctx,
147 char *page)
148{
149 return sprintf(page, "%u\n", hctx->tags->nr_tags);
150}
151
152static ssize_t blk_mq_hw_sysfs_nr_reserved_tags_show(struct blk_mq_hw_ctx *hctx,
153 char *page)
154{
155 return sprintf(page, "%u\n", hctx->tags->nr_reserved_tags);
156}
157
158static ssize_t blk_mq_hw_sysfs_cpus_show(struct blk_mq_hw_ctx *hctx, char *page)
159{
160 unsigned int i, first = 1;
161 ssize_t ret = 0;
162
163 for_each_cpu(i, hctx->cpumask) {
164 if (first)
165 ret += sprintf(ret + page, "%u", i);
166 else
167 ret += sprintf(ret + page, ", %u", i);
168
169 first = 0;
170 }
171
172 ret += sprintf(ret + page, "\n");
173 return ret;
174}
175
176static struct attribute *default_ctx_attrs[] = {
177 NULL,
178};
179
180static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_nr_tags = {
181 .attr = {.name = "nr_tags", .mode = 0444 },
182 .show = blk_mq_hw_sysfs_nr_tags_show,
183};
184static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_nr_reserved_tags = {
185 .attr = {.name = "nr_reserved_tags", .mode = 0444 },
186 .show = blk_mq_hw_sysfs_nr_reserved_tags_show,
187};
188static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_cpus = {
189 .attr = {.name = "cpu_list", .mode = 0444 },
190 .show = blk_mq_hw_sysfs_cpus_show,
191};
192
193static struct attribute *default_hw_ctx_attrs[] = {
194 &blk_mq_hw_sysfs_nr_tags.attr,
195 &blk_mq_hw_sysfs_nr_reserved_tags.attr,
196 &blk_mq_hw_sysfs_cpus.attr,
197 NULL,
198};
199
200static const struct sysfs_ops blk_mq_sysfs_ops = {
201 .show = blk_mq_sysfs_show,
202 .store = blk_mq_sysfs_store,
203};
204
205static const struct sysfs_ops blk_mq_hw_sysfs_ops = {
206 .show = blk_mq_hw_sysfs_show,
207 .store = blk_mq_hw_sysfs_store,
208};
209
210static struct kobj_type blk_mq_ktype = {
211 .sysfs_ops = &blk_mq_sysfs_ops,
212 .release = blk_mq_sysfs_release,
213};
214
215static struct kobj_type blk_mq_ctx_ktype = {
216 .sysfs_ops = &blk_mq_sysfs_ops,
217 .default_attrs = default_ctx_attrs,
218 .release = blk_mq_ctx_sysfs_release,
219};
220
221static struct kobj_type blk_mq_hw_ktype = {
222 .sysfs_ops = &blk_mq_hw_sysfs_ops,
223 .default_attrs = default_hw_ctx_attrs,
224 .release = blk_mq_hw_sysfs_release,
225};
226
227static void blk_mq_unregister_hctx(struct blk_mq_hw_ctx *hctx)
228{
229 struct blk_mq_ctx *ctx;
230 int i;
231
232 if (!hctx->nr_ctx)
233 return;
234
235 hctx_for_each_ctx(hctx, ctx, i)
236 kobject_del(&ctx->kobj);
237
238 kobject_del(&hctx->kobj);
239}
240
241static int blk_mq_register_hctx(struct blk_mq_hw_ctx *hctx)
242{
243 struct request_queue *q = hctx->queue;
244 struct blk_mq_ctx *ctx;
245 int i, ret;
246
247 if (!hctx->nr_ctx)
248 return 0;
249
250 ret = kobject_add(&hctx->kobj, q->mq_kobj, "%u", hctx->queue_num);
251 if (ret)
252 return ret;
253
254 hctx_for_each_ctx(hctx, ctx, i) {
255 ret = kobject_add(&ctx->kobj, &hctx->kobj, "cpu%u", ctx->cpu);
256 if (ret)
257 break;
258 }
259
260 return ret;
261}
262
263void blk_mq_unregister_dev(struct device *dev, struct request_queue *q)
264{
265 struct blk_mq_hw_ctx *hctx;
266 int i;
267
268 lockdep_assert_held(&q->sysfs_lock);
269
270 queue_for_each_hw_ctx(q, hctx, i)
271 blk_mq_unregister_hctx(hctx);
272
273 kobject_uevent(q->mq_kobj, KOBJ_REMOVE);
274 kobject_del(q->mq_kobj);
275 kobject_put(&dev->kobj);
276
277 q->mq_sysfs_init_done = false;
278}
279
280void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx)
281{
282 kobject_init(&hctx->kobj, &blk_mq_hw_ktype);
283}
284
285void blk_mq_sysfs_deinit(struct request_queue *q)
286{
287 struct blk_mq_ctx *ctx;
288 int cpu;
289
290 for_each_possible_cpu(cpu) {
291 ctx = per_cpu_ptr(q->queue_ctx, cpu);
292 kobject_put(&ctx->kobj);
293 }
294 kobject_put(q->mq_kobj);
295}
296
297void blk_mq_sysfs_init(struct request_queue *q)
298{
299 struct blk_mq_ctx *ctx;
300 int cpu;
301
302 kobject_init(q->mq_kobj, &blk_mq_ktype);
303
304 for_each_possible_cpu(cpu) {
305 ctx = per_cpu_ptr(q->queue_ctx, cpu);
306
307 kobject_get(q->mq_kobj);
308 kobject_init(&ctx->kobj, &blk_mq_ctx_ktype);
309 }
310}
311
312int __blk_mq_register_dev(struct device *dev, struct request_queue *q)
313{
314 struct blk_mq_hw_ctx *hctx;
315 int ret, i;
316
317 WARN_ON_ONCE(!q->kobj.parent);
318 lockdep_assert_held(&q->sysfs_lock);
319
320 ret = kobject_add(q->mq_kobj, kobject_get(&dev->kobj), "%s", "mq");
321 if (ret < 0)
322 goto out;
323
324 kobject_uevent(q->mq_kobj, KOBJ_ADD);
325
326 queue_for_each_hw_ctx(q, hctx, i) {
327 ret = blk_mq_register_hctx(hctx);
328 if (ret)
329 goto unreg;
330 }
331
332 q->mq_sysfs_init_done = true;
333
334out:
335 return ret;
336
337unreg:
338 while (--i >= 0)
339 blk_mq_unregister_hctx(q->queue_hw_ctx[i]);
340
341 kobject_uevent(q->mq_kobj, KOBJ_REMOVE);
342 kobject_del(q->mq_kobj);
343 kobject_put(&dev->kobj);
344 return ret;
345}
346
347int blk_mq_register_dev(struct device *dev, struct request_queue *q)
348{
349 int ret;
350
351 mutex_lock(&q->sysfs_lock);
352 ret = __blk_mq_register_dev(dev, q);
353 mutex_unlock(&q->sysfs_lock);
354
355 return ret;
356}
357
358void blk_mq_sysfs_unregister(struct request_queue *q)
359{
360 struct blk_mq_hw_ctx *hctx;
361 int i;
362
363 mutex_lock(&q->sysfs_lock);
364 if (!q->mq_sysfs_init_done)
365 goto unlock;
366
367 queue_for_each_hw_ctx(q, hctx, i)
368 blk_mq_unregister_hctx(hctx);
369
370unlock:
371 mutex_unlock(&q->sysfs_lock);
372}
373
374int blk_mq_sysfs_register(struct request_queue *q)
375{
376 struct blk_mq_hw_ctx *hctx;
377 int i, ret = 0;
378
379 mutex_lock(&q->sysfs_lock);
380 if (!q->mq_sysfs_init_done)
381 goto unlock;
382
383 queue_for_each_hw_ctx(q, hctx, i) {
384 ret = blk_mq_register_hctx(hctx);
385 if (ret)
386 break;
387 }
388
389unlock:
390 mutex_unlock(&q->sysfs_lock);
391
392 return ret;
393}
394