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.h"
14 #include "blk-mq.h"
15 #include "blk-mq-tag.h"
16
blk_mq_sysfs_release(struct kobject * kobj)17 static void blk_mq_sysfs_release(struct kobject *kobj)
18 {
19 }
20
blk_mq_hw_sysfs_release(struct kobject * kobj)21 static void blk_mq_hw_sysfs_release(struct kobject *kobj)
22 {
23 struct blk_mq_hw_ctx *hctx = container_of(kobj, struct blk_mq_hw_ctx,
24 kobj);
25
26 if (hctx->flags & BLK_MQ_F_BLOCKING)
27 cleanup_srcu_struct(hctx->srcu);
28 blk_free_flush_queue(hctx->fq);
29 sbitmap_free(&hctx->ctx_map);
30 free_cpumask_var(hctx->cpumask);
31 kfree(hctx->ctxs);
32 kfree(hctx);
33 }
34
35 struct blk_mq_ctx_sysfs_entry {
36 struct attribute attr;
37 ssize_t (*show)(struct blk_mq_ctx *, char *);
38 ssize_t (*store)(struct blk_mq_ctx *, const char *, size_t);
39 };
40
41 struct blk_mq_hw_ctx_sysfs_entry {
42 struct attribute attr;
43 ssize_t (*show)(struct blk_mq_hw_ctx *, char *);
44 ssize_t (*store)(struct blk_mq_hw_ctx *, const char *, size_t);
45 };
46
blk_mq_sysfs_show(struct kobject * kobj,struct attribute * attr,char * page)47 static ssize_t blk_mq_sysfs_show(struct kobject *kobj, struct attribute *attr,
48 char *page)
49 {
50 struct blk_mq_ctx_sysfs_entry *entry;
51 struct blk_mq_ctx *ctx;
52 struct request_queue *q;
53 ssize_t res;
54
55 entry = container_of(attr, struct blk_mq_ctx_sysfs_entry, attr);
56 ctx = container_of(kobj, struct blk_mq_ctx, kobj);
57 q = ctx->queue;
58
59 if (!entry->show)
60 return -EIO;
61
62 res = -ENOENT;
63 mutex_lock(&q->sysfs_lock);
64 if (!blk_queue_dying(q))
65 res = entry->show(ctx, page);
66 mutex_unlock(&q->sysfs_lock);
67 return res;
68 }
69
blk_mq_sysfs_store(struct kobject * kobj,struct attribute * attr,const char * page,size_t length)70 static ssize_t blk_mq_sysfs_store(struct kobject *kobj, struct attribute *attr,
71 const char *page, size_t length)
72 {
73 struct blk_mq_ctx_sysfs_entry *entry;
74 struct blk_mq_ctx *ctx;
75 struct request_queue *q;
76 ssize_t res;
77
78 entry = container_of(attr, struct blk_mq_ctx_sysfs_entry, attr);
79 ctx = container_of(kobj, struct blk_mq_ctx, kobj);
80 q = ctx->queue;
81
82 if (!entry->store)
83 return -EIO;
84
85 res = -ENOENT;
86 mutex_lock(&q->sysfs_lock);
87 if (!blk_queue_dying(q))
88 res = entry->store(ctx, page, length);
89 mutex_unlock(&q->sysfs_lock);
90 return res;
91 }
92
blk_mq_hw_sysfs_show(struct kobject * kobj,struct attribute * attr,char * page)93 static ssize_t blk_mq_hw_sysfs_show(struct kobject *kobj,
94 struct attribute *attr, char *page)
95 {
96 struct blk_mq_hw_ctx_sysfs_entry *entry;
97 struct blk_mq_hw_ctx *hctx;
98 struct request_queue *q;
99 ssize_t res;
100
101 entry = container_of(attr, struct blk_mq_hw_ctx_sysfs_entry, attr);
102 hctx = container_of(kobj, struct blk_mq_hw_ctx, kobj);
103 q = hctx->queue;
104
105 if (!entry->show)
106 return -EIO;
107
108 res = -ENOENT;
109 mutex_lock(&q->sysfs_lock);
110 if (!blk_queue_dying(q))
111 res = entry->show(hctx, page);
112 mutex_unlock(&q->sysfs_lock);
113 return res;
114 }
115
blk_mq_hw_sysfs_store(struct kobject * kobj,struct attribute * attr,const char * page,size_t length)116 static ssize_t blk_mq_hw_sysfs_store(struct kobject *kobj,
117 struct attribute *attr, const char *page,
118 size_t length)
119 {
120 struct blk_mq_hw_ctx_sysfs_entry *entry;
121 struct blk_mq_hw_ctx *hctx;
122 struct request_queue *q;
123 ssize_t res;
124
125 entry = container_of(attr, struct blk_mq_hw_ctx_sysfs_entry, attr);
126 hctx = container_of(kobj, struct blk_mq_hw_ctx, kobj);
127 q = hctx->queue;
128
129 if (!entry->store)
130 return -EIO;
131
132 res = -ENOENT;
133 mutex_lock(&q->sysfs_lock);
134 if (!blk_queue_dying(q))
135 res = entry->store(hctx, page, length);
136 mutex_unlock(&q->sysfs_lock);
137 return res;
138 }
139
blk_mq_hw_sysfs_nr_tags_show(struct blk_mq_hw_ctx * hctx,char * page)140 static ssize_t blk_mq_hw_sysfs_nr_tags_show(struct blk_mq_hw_ctx *hctx,
141 char *page)
142 {
143 return sprintf(page, "%u\n", hctx->tags->nr_tags);
144 }
145
blk_mq_hw_sysfs_nr_reserved_tags_show(struct blk_mq_hw_ctx * hctx,char * page)146 static ssize_t blk_mq_hw_sysfs_nr_reserved_tags_show(struct blk_mq_hw_ctx *hctx,
147 char *page)
148 {
149 return sprintf(page, "%u\n", hctx->tags->nr_reserved_tags);
150 }
151
blk_mq_hw_sysfs_cpus_show(struct blk_mq_hw_ctx * hctx,char * page)152 static ssize_t blk_mq_hw_sysfs_cpus_show(struct blk_mq_hw_ctx *hctx, char *page)
153 {
154 const size_t size = PAGE_SIZE - 1;
155 unsigned int i, first = 1;
156 int ret = 0, pos = 0;
157
158 for_each_cpu(i, hctx->cpumask) {
159 if (first)
160 ret = snprintf(pos + page, size - pos, "%u", i);
161 else
162 ret = snprintf(pos + page, size - pos, ", %u", i);
163
164 if (ret >= size - pos)
165 break;
166
167 first = 0;
168 pos += ret;
169 }
170
171 ret = snprintf(pos + page, size + 1 - pos, "\n");
172 return pos + ret;
173 }
174
175 static struct attribute *default_ctx_attrs[] = {
176 NULL,
177 };
178
179 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_nr_tags = {
180 .attr = {.name = "nr_tags", .mode = 0444 },
181 .show = blk_mq_hw_sysfs_nr_tags_show,
182 };
183 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_nr_reserved_tags = {
184 .attr = {.name = "nr_reserved_tags", .mode = 0444 },
185 .show = blk_mq_hw_sysfs_nr_reserved_tags_show,
186 };
187 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_cpus = {
188 .attr = {.name = "cpu_list", .mode = 0444 },
189 .show = blk_mq_hw_sysfs_cpus_show,
190 };
191
192 static struct attribute *default_hw_ctx_attrs[] = {
193 &blk_mq_hw_sysfs_nr_tags.attr,
194 &blk_mq_hw_sysfs_nr_reserved_tags.attr,
195 &blk_mq_hw_sysfs_cpus.attr,
196 NULL,
197 };
198
199 static const struct sysfs_ops blk_mq_sysfs_ops = {
200 .show = blk_mq_sysfs_show,
201 .store = blk_mq_sysfs_store,
202 };
203
204 static const struct sysfs_ops blk_mq_hw_sysfs_ops = {
205 .show = blk_mq_hw_sysfs_show,
206 .store = blk_mq_hw_sysfs_store,
207 };
208
209 static struct kobj_type blk_mq_ktype = {
210 .sysfs_ops = &blk_mq_sysfs_ops,
211 .release = blk_mq_sysfs_release,
212 };
213
214 static struct kobj_type blk_mq_ctx_ktype = {
215 .sysfs_ops = &blk_mq_sysfs_ops,
216 .default_attrs = default_ctx_attrs,
217 .release = blk_mq_sysfs_release,
218 };
219
220 static struct kobj_type blk_mq_hw_ktype = {
221 .sysfs_ops = &blk_mq_hw_sysfs_ops,
222 .default_attrs = default_hw_ctx_attrs,
223 .release = blk_mq_hw_sysfs_release,
224 };
225
blk_mq_unregister_hctx(struct blk_mq_hw_ctx * hctx)226 static void blk_mq_unregister_hctx(struct blk_mq_hw_ctx *hctx)
227 {
228 struct blk_mq_ctx *ctx;
229 int i;
230
231 if (!hctx->nr_ctx)
232 return;
233
234 hctx_for_each_ctx(hctx, ctx, i)
235 kobject_del(&ctx->kobj);
236
237 kobject_del(&hctx->kobj);
238 }
239
blk_mq_register_hctx(struct blk_mq_hw_ctx * hctx)240 static int blk_mq_register_hctx(struct blk_mq_hw_ctx *hctx)
241 {
242 struct request_queue *q = hctx->queue;
243 struct blk_mq_ctx *ctx;
244 int i, j, ret;
245
246 if (!hctx->nr_ctx)
247 return 0;
248
249 ret = kobject_add(&hctx->kobj, &q->mq_kobj, "%u", hctx->queue_num);
250 if (ret)
251 return ret;
252
253 hctx_for_each_ctx(hctx, ctx, i) {
254 ret = kobject_add(&ctx->kobj, &hctx->kobj, "cpu%u", ctx->cpu);
255 if (ret)
256 goto out;
257 }
258
259 return 0;
260 out:
261 hctx_for_each_ctx(hctx, ctx, j) {
262 if (j < i)
263 kobject_del(&ctx->kobj);
264 }
265 kobject_del(&hctx->kobj);
266 return ret;
267 }
268
blk_mq_unregister_dev(struct device * dev,struct request_queue * q)269 void blk_mq_unregister_dev(struct device *dev, struct request_queue *q)
270 {
271 struct blk_mq_hw_ctx *hctx;
272 int i;
273
274 lockdep_assert_held(&q->sysfs_dir_lock);
275
276 queue_for_each_hw_ctx(q, hctx, i)
277 blk_mq_unregister_hctx(hctx);
278
279 kobject_uevent(&q->mq_kobj, KOBJ_REMOVE);
280 kobject_del(&q->mq_kobj);
281 kobject_put(&dev->kobj);
282
283 q->mq_sysfs_init_done = false;
284 }
285
blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx * hctx)286 void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx)
287 {
288 kobject_init(&hctx->kobj, &blk_mq_hw_ktype);
289 }
290
blk_mq_sysfs_deinit(struct request_queue * q)291 void blk_mq_sysfs_deinit(struct request_queue *q)
292 {
293 struct blk_mq_ctx *ctx;
294 int cpu;
295
296 for_each_possible_cpu(cpu) {
297 ctx = per_cpu_ptr(q->queue_ctx, cpu);
298 kobject_put(&ctx->kobj);
299 }
300 kobject_put(&q->mq_kobj);
301 }
302
blk_mq_sysfs_init(struct request_queue * q)303 void blk_mq_sysfs_init(struct request_queue *q)
304 {
305 struct blk_mq_ctx *ctx;
306 int cpu;
307
308 kobject_init(&q->mq_kobj, &blk_mq_ktype);
309
310 for_each_possible_cpu(cpu) {
311 ctx = per_cpu_ptr(q->queue_ctx, cpu);
312 kobject_init(&ctx->kobj, &blk_mq_ctx_ktype);
313 }
314 }
315
__blk_mq_register_dev(struct device * dev,struct request_queue * q)316 int __blk_mq_register_dev(struct device *dev, struct request_queue *q)
317 {
318 struct blk_mq_hw_ctx *hctx;
319 int ret, i;
320
321 WARN_ON_ONCE(!q->kobj.parent);
322 lockdep_assert_held(&q->sysfs_dir_lock);
323
324 ret = kobject_add(&q->mq_kobj, kobject_get(&dev->kobj), "%s", "mq");
325 if (ret < 0)
326 goto out;
327
328 kobject_uevent(&q->mq_kobj, KOBJ_ADD);
329
330 queue_for_each_hw_ctx(q, hctx, i) {
331 ret = blk_mq_register_hctx(hctx);
332 if (ret)
333 goto unreg;
334 }
335
336 q->mq_sysfs_init_done = true;
337
338 out:
339 return ret;
340
341 unreg:
342 while (--i >= 0)
343 blk_mq_unregister_hctx(q->queue_hw_ctx[i]);
344
345 kobject_uevent(&q->mq_kobj, KOBJ_REMOVE);
346 kobject_del(&q->mq_kobj);
347 kobject_put(&dev->kobj);
348 return ret;
349 }
350
blk_mq_register_dev(struct device * dev,struct request_queue * q)351 int blk_mq_register_dev(struct device *dev, struct request_queue *q)
352 {
353 int ret;
354
355 mutex_lock(&q->sysfs_lock);
356 ret = __blk_mq_register_dev(dev, q);
357 mutex_unlock(&q->sysfs_lock);
358
359 return ret;
360 }
361 EXPORT_SYMBOL_GPL(blk_mq_register_dev);
362
blk_mq_sysfs_unregister(struct request_queue * q)363 void blk_mq_sysfs_unregister(struct request_queue *q)
364 {
365 struct blk_mq_hw_ctx *hctx;
366 int i;
367
368 mutex_lock(&q->sysfs_dir_lock);
369 if (!q->mq_sysfs_init_done)
370 goto unlock;
371
372 queue_for_each_hw_ctx(q, hctx, i)
373 blk_mq_unregister_hctx(hctx);
374
375 unlock:
376 mutex_unlock(&q->sysfs_dir_lock);
377 }
378
blk_mq_sysfs_register(struct request_queue * q)379 int blk_mq_sysfs_register(struct request_queue *q)
380 {
381 struct blk_mq_hw_ctx *hctx;
382 int i, ret = 0;
383
384 mutex_lock(&q->sysfs_dir_lock);
385 if (!q->mq_sysfs_init_done)
386 goto unlock;
387
388 queue_for_each_hw_ctx(q, hctx, i) {
389 ret = blk_mq_register_hctx(hctx);
390 if (ret)
391 break;
392 }
393
394 unlock:
395 mutex_unlock(&q->sysfs_dir_lock);
396
397 return ret;
398 }
399