block/blk-mq-sysfs.c

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