1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/kernel.h>
3 #include <linux/module.h>
4 #include <linux/backing-dev.h>
5 #include <linux/bio.h>
6 #include <linux/blkdev.h>
7 #include <linux/mm.h>
8 #include <linux/init.h>
9 #include <linux/slab.h>
10 #include <linux/workqueue.h>
11 #include <linux/smp.h>
12
13 #include <linux/blk-mq.h>
14 #include "blk.h"
15 #include "blk-mq.h"
16 #include "blk-mq-tag.h"
17
blk_mq_sysfs_release(struct kobject * kobj)18 static void blk_mq_sysfs_release(struct kobject *kobj)
19 {
20 struct blk_mq_ctxs *ctxs = container_of(kobj, struct blk_mq_ctxs, kobj);
21
22 free_percpu(ctxs->queue_ctx);
23 kfree(ctxs);
24 }
25
blk_mq_ctx_sysfs_release(struct kobject * kobj)26 static void blk_mq_ctx_sysfs_release(struct kobject *kobj)
27 {
28 struct blk_mq_ctx *ctx = container_of(kobj, struct blk_mq_ctx, kobj);
29
30 /* ctx->ctxs won't be released until all ctx are freed */
31 kobject_put(&ctx->ctxs->kobj);
32 }
33
blk_mq_hw_sysfs_release(struct kobject * kobj)34 static void blk_mq_hw_sysfs_release(struct kobject *kobj)
35 {
36 struct blk_mq_hw_ctx *hctx = container_of(kobj, struct blk_mq_hw_ctx,
37 kobj);
38
39 cancel_delayed_work_sync(&hctx->run_work);
40
41 if (hctx->flags & BLK_MQ_F_BLOCKING)
42 cleanup_srcu_struct(hctx->srcu);
43 blk_free_flush_queue(hctx->fq);
44 sbitmap_free(&hctx->ctx_map);
45 free_cpumask_var(hctx->cpumask);
46 kfree(hctx->ctxs);
47 kfree(hctx);
48 }
49
50 struct blk_mq_ctx_sysfs_entry {
51 struct attribute attr;
52 ssize_t (*show)(struct blk_mq_ctx *, char *);
53 ssize_t (*store)(struct blk_mq_ctx *, const char *, size_t);
54 };
55
56 struct blk_mq_hw_ctx_sysfs_entry {
57 struct attribute attr;
58 ssize_t (*show)(struct blk_mq_hw_ctx *, char *);
59 ssize_t (*store)(struct blk_mq_hw_ctx *, const char *, size_t);
60 };
61
blk_mq_sysfs_show(struct kobject * kobj,struct attribute * attr,char * page)62 static ssize_t blk_mq_sysfs_show(struct kobject *kobj, struct attribute *attr,
63 char *page)
64 {
65 struct blk_mq_ctx_sysfs_entry *entry;
66 struct blk_mq_ctx *ctx;
67 struct request_queue *q;
68 ssize_t res;
69
70 entry = container_of(attr, struct blk_mq_ctx_sysfs_entry, attr);
71 ctx = container_of(kobj, struct blk_mq_ctx, kobj);
72 q = ctx->queue;
73
74 if (!entry->show)
75 return -EIO;
76
77 res = -ENOENT;
78 mutex_lock(&q->sysfs_lock);
79 if (!blk_queue_dying(q))
80 res = entry->show(ctx, page);
81 mutex_unlock(&q->sysfs_lock);
82 return res;
83 }
84
blk_mq_sysfs_store(struct kobject * kobj,struct attribute * attr,const char * page,size_t length)85 static ssize_t blk_mq_sysfs_store(struct kobject *kobj, struct attribute *attr,
86 const char *page, size_t length)
87 {
88 struct blk_mq_ctx_sysfs_entry *entry;
89 struct blk_mq_ctx *ctx;
90 struct request_queue *q;
91 ssize_t res;
92
93 entry = container_of(attr, struct blk_mq_ctx_sysfs_entry, attr);
94 ctx = container_of(kobj, struct blk_mq_ctx, kobj);
95 q = ctx->queue;
96
97 if (!entry->store)
98 return -EIO;
99
100 res = -ENOENT;
101 mutex_lock(&q->sysfs_lock);
102 if (!blk_queue_dying(q))
103 res = entry->store(ctx, page, length);
104 mutex_unlock(&q->sysfs_lock);
105 return res;
106 }
107
blk_mq_hw_sysfs_show(struct kobject * kobj,struct attribute * attr,char * page)108 static ssize_t blk_mq_hw_sysfs_show(struct kobject *kobj,
109 struct attribute *attr, char *page)
110 {
111 struct blk_mq_hw_ctx_sysfs_entry *entry;
112 struct blk_mq_hw_ctx *hctx;
113 struct request_queue *q;
114 ssize_t res;
115
116 entry = container_of(attr, struct blk_mq_hw_ctx_sysfs_entry, attr);
117 hctx = container_of(kobj, struct blk_mq_hw_ctx, kobj);
118 q = hctx->queue;
119
120 if (!entry->show)
121 return -EIO;
122
123 res = -ENOENT;
124 mutex_lock(&q->sysfs_lock);
125 if (!blk_queue_dying(q))
126 res = entry->show(hctx, page);
127 mutex_unlock(&q->sysfs_lock);
128 return res;
129 }
130
blk_mq_hw_sysfs_store(struct kobject * kobj,struct attribute * attr,const char * page,size_t length)131 static ssize_t blk_mq_hw_sysfs_store(struct kobject *kobj,
132 struct attribute *attr, const char *page,
133 size_t length)
134 {
135 struct blk_mq_hw_ctx_sysfs_entry *entry;
136 struct blk_mq_hw_ctx *hctx;
137 struct request_queue *q;
138 ssize_t res;
139
140 entry = container_of(attr, struct blk_mq_hw_ctx_sysfs_entry, attr);
141 hctx = container_of(kobj, struct blk_mq_hw_ctx, kobj);
142 q = hctx->queue;
143
144 if (!entry->store)
145 return -EIO;
146
147 res = -ENOENT;
148 mutex_lock(&q->sysfs_lock);
149 if (!blk_queue_dying(q))
150 res = entry->store(hctx, page, length);
151 mutex_unlock(&q->sysfs_lock);
152 return res;
153 }
154
blk_mq_hw_sysfs_nr_tags_show(struct blk_mq_hw_ctx * hctx,char * page)155 static ssize_t blk_mq_hw_sysfs_nr_tags_show(struct blk_mq_hw_ctx *hctx,
156 char *page)
157 {
158 return sprintf(page, "%u\n", hctx->tags->nr_tags);
159 }
160
blk_mq_hw_sysfs_nr_reserved_tags_show(struct blk_mq_hw_ctx * hctx,char * page)161 static ssize_t blk_mq_hw_sysfs_nr_reserved_tags_show(struct blk_mq_hw_ctx *hctx,
162 char *page)
163 {
164 return sprintf(page, "%u\n", hctx->tags->nr_reserved_tags);
165 }
166
blk_mq_hw_sysfs_cpus_show(struct blk_mq_hw_ctx * hctx,char * page)167 static ssize_t blk_mq_hw_sysfs_cpus_show(struct blk_mq_hw_ctx *hctx, char *page)
168 {
169 const size_t size = PAGE_SIZE - 1;
170 unsigned int i, first = 1;
171 int ret = 0, pos = 0;
172
173 for_each_cpu(i, hctx->cpumask) {
174 if (first)
175 ret = snprintf(pos + page, size - pos, "%u", i);
176 else
177 ret = snprintf(pos + page, size - pos, ", %u", i);
178
179 if (ret >= size - pos)
180 break;
181
182 first = 0;
183 pos += ret;
184 }
185
186 ret = snprintf(pos + page, size + 1 - pos, "\n");
187 return pos + ret;
188 }
189
190 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_nr_tags = {
191 .attr = {.name = "nr_tags", .mode = 0444 },
192 .show = blk_mq_hw_sysfs_nr_tags_show,
193 };
194 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_nr_reserved_tags = {
195 .attr = {.name = "nr_reserved_tags", .mode = 0444 },
196 .show = blk_mq_hw_sysfs_nr_reserved_tags_show,
197 };
198 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_cpus = {
199 .attr = {.name = "cpu_list", .mode = 0444 },
200 .show = blk_mq_hw_sysfs_cpus_show,
201 };
202
203 static struct attribute *default_hw_ctx_attrs[] = {
204 &blk_mq_hw_sysfs_nr_tags.attr,
205 &blk_mq_hw_sysfs_nr_reserved_tags.attr,
206 &blk_mq_hw_sysfs_cpus.attr,
207 NULL,
208 };
209 ATTRIBUTE_GROUPS(default_hw_ctx);
210
211 static const struct sysfs_ops blk_mq_sysfs_ops = {
212 .show = blk_mq_sysfs_show,
213 .store = blk_mq_sysfs_store,
214 };
215
216 static const struct sysfs_ops blk_mq_hw_sysfs_ops = {
217 .show = blk_mq_hw_sysfs_show,
218 .store = blk_mq_hw_sysfs_store,
219 };
220
221 static struct kobj_type blk_mq_ktype = {
222 .sysfs_ops = &blk_mq_sysfs_ops,
223 .release = blk_mq_sysfs_release,
224 };
225
226 static struct kobj_type blk_mq_ctx_ktype = {
227 .sysfs_ops = &blk_mq_sysfs_ops,
228 .release = blk_mq_ctx_sysfs_release,
229 };
230
231 static struct kobj_type blk_mq_hw_ktype = {
232 .sysfs_ops = &blk_mq_hw_sysfs_ops,
233 .default_groups = default_hw_ctx_groups,
234 .release = blk_mq_hw_sysfs_release,
235 };
236
blk_mq_unregister_hctx(struct blk_mq_hw_ctx * hctx)237 static void blk_mq_unregister_hctx(struct blk_mq_hw_ctx *hctx)
238 {
239 struct blk_mq_ctx *ctx;
240 int i;
241
242 if (!hctx->nr_ctx)
243 return;
244
245 hctx_for_each_ctx(hctx, ctx, i)
246 kobject_del(&ctx->kobj);
247
248 kobject_del(&hctx->kobj);
249 }
250
blk_mq_register_hctx(struct blk_mq_hw_ctx * hctx)251 static int blk_mq_register_hctx(struct blk_mq_hw_ctx *hctx)
252 {
253 struct request_queue *q = hctx->queue;
254 struct blk_mq_ctx *ctx;
255 int i, ret;
256
257 if (!hctx->nr_ctx)
258 return 0;
259
260 ret = kobject_add(&hctx->kobj, q->mq_kobj, "%u", hctx->queue_num);
261 if (ret)
262 return ret;
263
264 hctx_for_each_ctx(hctx, ctx, i) {
265 ret = kobject_add(&ctx->kobj, &hctx->kobj, "cpu%u", ctx->cpu);
266 if (ret)
267 break;
268 }
269
270 return ret;
271 }
272
blk_mq_unregister_dev(struct device * dev,struct request_queue * q)273 void blk_mq_unregister_dev(struct device *dev, struct request_queue *q)
274 {
275 struct blk_mq_hw_ctx *hctx;
276 int i;
277
278 lockdep_assert_held(&q->sysfs_dir_lock);
279
280 queue_for_each_hw_ctx(q, hctx, i)
281 blk_mq_unregister_hctx(hctx);
282
283 kobject_uevent(q->mq_kobj, KOBJ_REMOVE);
284 kobject_del(q->mq_kobj);
285 kobject_put(&dev->kobj);
286
287 q->mq_sysfs_init_done = false;
288 }
289
blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx * hctx)290 void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx)
291 {
292 kobject_init(&hctx->kobj, &blk_mq_hw_ktype);
293 }
294
blk_mq_sysfs_deinit(struct request_queue * q)295 void blk_mq_sysfs_deinit(struct request_queue *q)
296 {
297 struct blk_mq_ctx *ctx;
298 int cpu;
299
300 for_each_possible_cpu(cpu) {
301 ctx = per_cpu_ptr(q->queue_ctx, cpu);
302 kobject_put(&ctx->kobj);
303 }
304 kobject_put(q->mq_kobj);
305 }
306
blk_mq_sysfs_init(struct request_queue * q)307 void blk_mq_sysfs_init(struct request_queue *q)
308 {
309 struct blk_mq_ctx *ctx;
310 int cpu;
311
312 kobject_init(q->mq_kobj, &blk_mq_ktype);
313
314 for_each_possible_cpu(cpu) {
315 ctx = per_cpu_ptr(q->queue_ctx, cpu);
316
317 kobject_get(q->mq_kobj);
318 kobject_init(&ctx->kobj, &blk_mq_ctx_ktype);
319 }
320 }
321
__blk_mq_register_dev(struct device * dev,struct request_queue * q)322 int __blk_mq_register_dev(struct device *dev, struct request_queue *q)
323 {
324 struct blk_mq_hw_ctx *hctx;
325 int ret, i;
326
327 WARN_ON_ONCE(!q->kobj.parent);
328 lockdep_assert_held(&q->sysfs_dir_lock);
329
330 ret = kobject_add(q->mq_kobj, kobject_get(&dev->kobj), "%s", "mq");
331 if (ret < 0)
332 goto out;
333
334 kobject_uevent(q->mq_kobj, KOBJ_ADD);
335
336 queue_for_each_hw_ctx(q, hctx, i) {
337 ret = blk_mq_register_hctx(hctx);
338 if (ret)
339 goto unreg;
340 }
341
342 q->mq_sysfs_init_done = true;
343
344 out:
345 return ret;
346
347 unreg:
348 while (--i >= 0)
349 blk_mq_unregister_hctx(q->queue_hw_ctx[i]);
350
351 kobject_uevent(q->mq_kobj, KOBJ_REMOVE);
352 kobject_del(q->mq_kobj);
353 kobject_put(&dev->kobj);
354 return ret;
355 }
356
blk_mq_sysfs_unregister(struct request_queue * q)357 void blk_mq_sysfs_unregister(struct request_queue *q)
358 {
359 struct blk_mq_hw_ctx *hctx;
360 int i;
361
362 mutex_lock(&q->sysfs_dir_lock);
363 if (!q->mq_sysfs_init_done)
364 goto unlock;
365
366 queue_for_each_hw_ctx(q, hctx, i)
367 blk_mq_unregister_hctx(hctx);
368
369 unlock:
370 mutex_unlock(&q->sysfs_dir_lock);
371 }
372
blk_mq_sysfs_register(struct request_queue * q)373 int blk_mq_sysfs_register(struct request_queue *q)
374 {
375 struct blk_mq_hw_ctx *hctx;
376 int i, ret = 0;
377
378 mutex_lock(&q->sysfs_dir_lock);
379 if (!q->mq_sysfs_init_done)
380 goto unlock;
381
382 queue_for_each_hw_ctx(q, hctx, i) {
383 ret = blk_mq_register_hctx(hctx);
384 if (ret)
385 break;
386 }
387
388 unlock:
389 mutex_unlock(&q->sysfs_dir_lock);
390
391 return ret;
392 }
393