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