block/blk-mq-sysfs.c

   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
  16 static void blk_mq_sysfs_release(struct kobject *kobj)
  17 {
  18 }
  19
  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
  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
  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
  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
 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
 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
 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
 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
 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
 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
 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
 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
 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
 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
 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
 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
 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
 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 }