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 if (hctx->flags & BLK_MQ_F_BLOCKING)
40 cleanup_srcu_struct(hctx->srcu);
41 blk_free_flush_queue(hctx->fq);
42 sbitmap_free(&hctx->ctx_map);
43 free_cpumask_var(hctx->cpumask);
44 kfree(hctx->ctxs);
45 kfree(hctx);
46 }
47
48 struct blk_mq_ctx_sysfs_entry {
49 struct attribute attr;
50 ssize_t (*show)(struct blk_mq_ctx *, char *);
51 ssize_t (*store)(struct blk_mq_ctx *, const char *, size_t);
52 };
53
54 struct blk_mq_hw_ctx_sysfs_entry {
55 struct attribute attr;
56 ssize_t (*show)(struct blk_mq_hw_ctx *, char *);
57 ssize_t (*store)(struct blk_mq_hw_ctx *, const char *, size_t);
58 };
59
blk_mq_sysfs_show(struct kobject * kobj,struct attribute * attr,char * page)60 static ssize_t blk_mq_sysfs_show(struct kobject *kobj, struct attribute *attr,
61 char *page)
62 {
63 struct blk_mq_ctx_sysfs_entry *entry;
64 struct blk_mq_ctx *ctx;
65 struct request_queue *q;
66 ssize_t res;
67
68 entry = container_of(attr, struct blk_mq_ctx_sysfs_entry, attr);
69 ctx = container_of(kobj, struct blk_mq_ctx, kobj);
70 q = ctx->queue;
71
72 if (!entry->show)
73 return -EIO;
74
75 mutex_lock(&q->sysfs_lock);
76 res = entry->show(ctx, page);
77 mutex_unlock(&q->sysfs_lock);
78 return res;
79 }
80
blk_mq_sysfs_store(struct kobject * kobj,struct attribute * attr,const char * page,size_t length)81 static ssize_t blk_mq_sysfs_store(struct kobject *kobj, struct attribute *attr,
82 const char *page, size_t length)
83 {
84 struct blk_mq_ctx_sysfs_entry *entry;
85 struct blk_mq_ctx *ctx;
86 struct request_queue *q;
87 ssize_t res;
88
89 entry = container_of(attr, struct blk_mq_ctx_sysfs_entry, attr);
90 ctx = container_of(kobj, struct blk_mq_ctx, kobj);
91 q = ctx->queue;
92
93 if (!entry->store)
94 return -EIO;
95
96 mutex_lock(&q->sysfs_lock);
97 res = entry->store(ctx, page, length);
98 mutex_unlock(&q->sysfs_lock);
99 return res;
100 }
101
blk_mq_hw_sysfs_show(struct kobject * kobj,struct attribute * attr,char * page)102 static ssize_t blk_mq_hw_sysfs_show(struct kobject *kobj,
103 struct attribute *attr, char *page)
104 {
105 struct blk_mq_hw_ctx_sysfs_entry *entry;
106 struct blk_mq_hw_ctx *hctx;
107 struct request_queue *q;
108 ssize_t res;
109
110 entry = container_of(attr, struct blk_mq_hw_ctx_sysfs_entry, attr);
111 hctx = container_of(kobj, struct blk_mq_hw_ctx, kobj);
112 q = hctx->queue;
113
114 if (!entry->show)
115 return -EIO;
116
117 mutex_lock(&q->sysfs_lock);
118 res = entry->show(hctx, page);
119 mutex_unlock(&q->sysfs_lock);
120 return res;
121 }
122
blk_mq_hw_sysfs_store(struct kobject * kobj,struct attribute * attr,const char * page,size_t length)123 static ssize_t blk_mq_hw_sysfs_store(struct kobject *kobj,
124 struct attribute *attr, const char *page,
125 size_t length)
126 {
127 struct blk_mq_hw_ctx_sysfs_entry *entry;
128 struct blk_mq_hw_ctx *hctx;
129 struct request_queue *q;
130 ssize_t res;
131
132 entry = container_of(attr, struct blk_mq_hw_ctx_sysfs_entry, attr);
133 hctx = container_of(kobj, struct blk_mq_hw_ctx, kobj);
134 q = hctx->queue;
135
136 if (!entry->store)
137 return -EIO;
138
139 mutex_lock(&q->sysfs_lock);
140 res = entry->store(hctx, page, length);
141 mutex_unlock(&q->sysfs_lock);
142 return res;
143 }
144
blk_mq_hw_sysfs_nr_tags_show(struct blk_mq_hw_ctx * hctx,char * page)145 static ssize_t blk_mq_hw_sysfs_nr_tags_show(struct blk_mq_hw_ctx *hctx,
146 char *page)
147 {
148 return sprintf(page, "%u\n", hctx->tags->nr_tags);
149 }
150
blk_mq_hw_sysfs_nr_reserved_tags_show(struct blk_mq_hw_ctx * hctx,char * page)151 static ssize_t blk_mq_hw_sysfs_nr_reserved_tags_show(struct blk_mq_hw_ctx *hctx,
152 char *page)
153 {
154 return sprintf(page, "%u\n", hctx->tags->nr_reserved_tags);
155 }
156
blk_mq_hw_sysfs_cpus_show(struct blk_mq_hw_ctx * hctx,char * page)157 static ssize_t blk_mq_hw_sysfs_cpus_show(struct blk_mq_hw_ctx *hctx, char *page)
158 {
159 const size_t size = PAGE_SIZE - 1;
160 unsigned int i, first = 1;
161 int ret = 0, pos = 0;
162
163 for_each_cpu(i, hctx->cpumask) {
164 if (first)
165 ret = snprintf(pos + page, size - pos, "%u", i);
166 else
167 ret = snprintf(pos + page, size - pos, ", %u", i);
168
169 if (ret >= size - pos)
170 break;
171
172 first = 0;
173 pos += ret;
174 }
175
176 ret = snprintf(pos + page, size + 1 - pos, "\n");
177 return pos + ret;
178 }
179
180 static 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 };
184 static 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 };
188 static 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
193 static 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 ATTRIBUTE_GROUPS(default_hw_ctx);
200
201 static const struct sysfs_ops blk_mq_sysfs_ops = {
202 .show = blk_mq_sysfs_show,
203 .store = blk_mq_sysfs_store,
204 };
205
206 static const struct sysfs_ops blk_mq_hw_sysfs_ops = {
207 .show = blk_mq_hw_sysfs_show,
208 .store = blk_mq_hw_sysfs_store,
209 };
210
211 static struct kobj_type blk_mq_ktype = {
212 .sysfs_ops = &blk_mq_sysfs_ops,
213 .release = blk_mq_sysfs_release,
214 };
215
216 static struct kobj_type blk_mq_ctx_ktype = {
217 .sysfs_ops = &blk_mq_sysfs_ops,
218 .release = blk_mq_ctx_sysfs_release,
219 };
220
221 static struct kobj_type blk_mq_hw_ktype = {
222 .sysfs_ops = &blk_mq_hw_sysfs_ops,
223 .default_groups = default_hw_ctx_groups,
224 .release = blk_mq_hw_sysfs_release,
225 };
226
blk_mq_unregister_hctx(struct blk_mq_hw_ctx * hctx)227 static 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
blk_mq_register_hctx(struct blk_mq_hw_ctx * hctx)241 static 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
blk_mq_unregister_dev(struct device * dev,struct request_queue * q)263 void 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_dir_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
blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx * hctx)280 void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx)
281 {
282 kobject_init(&hctx->kobj, &blk_mq_hw_ktype);
283 }
284
blk_mq_sysfs_deinit(struct request_queue * q)285 void 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
blk_mq_sysfs_init(struct request_queue * q)297 void 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
__blk_mq_register_dev(struct device * dev,struct request_queue * q)312 int __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_dir_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
334 out:
335 return ret;
336
337 unreg:
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
blk_mq_sysfs_unregister(struct request_queue * q)347 void blk_mq_sysfs_unregister(struct request_queue *q)
348 {
349 struct blk_mq_hw_ctx *hctx;
350 int i;
351
352 mutex_lock(&q->sysfs_dir_lock);
353 if (!q->mq_sysfs_init_done)
354 goto unlock;
355
356 queue_for_each_hw_ctx(q, hctx, i)
357 blk_mq_unregister_hctx(hctx);
358
359 unlock:
360 mutex_unlock(&q->sysfs_dir_lock);
361 }
362
blk_mq_sysfs_register(struct request_queue * q)363 int blk_mq_sysfs_register(struct request_queue *q)
364 {
365 struct blk_mq_hw_ctx *hctx;
366 int i, ret = 0;
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 ret = blk_mq_register_hctx(hctx);
374 if (ret)
375 break;
376 }
377
378 unlock:
379 mutex_unlock(&q->sysfs_dir_lock);
380
381 return ret;
382 }
383
