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         struct blk_mq_ctxs *ctxs = container_of(kobj, struct blk_mq_ctxs, kobj);
  19
  20         free_percpu(ctxs->queue_ctx);
  21         kfree(ctxs);
  22 }
  23
  24 static void blk_mq_ctx_sysfs_release(struct kobject *kobj)
  25 {
  26         struct blk_mq_ctx *ctx = container_of(kobj, struct blk_mq_ctx, kobj);
  27
  28         /* ctx->ctxs won't be released until all ctx are freed */
  29         kobject_put(&ctx->ctxs->kobj);
  30 }
  31
  32 static void blk_mq_hw_sysfs_release(struct kobject *kobj)
  33 {
  34         struct blk_mq_hw_ctx *hctx = container_of(kobj, struct blk_mq_hw_ctx,
  35                                                   kobj);
  36         free_cpumask_var(hctx->cpumask);
  37         kfree(hctx->ctxs);
  38         kfree(hctx);
  39 }
  40
  41 struct blk_mq_ctx_sysfs_entry {
  42         struct attribute attr;
  43         ssize_t (*show)(struct blk_mq_ctx *, char *);
  44         ssize_t (*store)(struct blk_mq_ctx *, const char *, size_t);
  45 };
  46
  47 struct blk_mq_hw_ctx_sysfs_entry {
  48         struct attribute attr;
  49         ssize_t (*show)(struct blk_mq_hw_ctx *, char *);
  50         ssize_t (*store)(struct blk_mq_hw_ctx *, const char *, size_t);
  51 };
  52
  53 static ssize_t blk_mq_sysfs_show(struct kobject *kobj, struct attribute *attr,
  54                                  char *page)
  55 {
  56         struct blk_mq_ctx_sysfs_entry *entry;
  57         struct blk_mq_ctx *ctx;
  58         struct request_queue *q;
  59         ssize_t res;
  60
  61         entry = container_of(attr, struct blk_mq_ctx_sysfs_entry, attr);
  62         ctx = container_of(kobj, struct blk_mq_ctx, kobj);
  63         q = ctx->queue;
  64
  65         if (!entry->show)
  66                 return -EIO;
  67
  68         res = -ENOENT;
  69         mutex_lock(&q->sysfs_lock);
  70         if (!blk_queue_dying(q))
  71                 res = entry->show(ctx, page);
  72         mutex_unlock(&q->sysfs_lock);
  73         return res;
  74 }
  75
  76 static ssize_t blk_mq_sysfs_store(struct kobject *kobj, struct attribute *attr,
  77                                   const char *page, size_t length)
  78 {
  79         struct blk_mq_ctx_sysfs_entry *entry;
  80         struct blk_mq_ctx *ctx;
  81         struct request_queue *q;
  82         ssize_t res;
  83
  84         entry = container_of(attr, struct blk_mq_ctx_sysfs_entry, attr);
  85         ctx = container_of(kobj, struct blk_mq_ctx, kobj);
  86         q = ctx->queue;
  87
  88         if (!entry->store)
  89                 return -EIO;
  90
  91         res = -ENOENT;
  92         mutex_lock(&q->sysfs_lock);
  93         if (!blk_queue_dying(q))
  94                 res = entry->store(ctx, page, length);
  95         mutex_unlock(&q->sysfs_lock);
  96         return res;
  97 }
  98
  99 static ssize_t blk_mq_hw_sysfs_show(struct kobject *kobj,
 100                                     struct attribute *attr, char *page)
 101 {
 102         struct blk_mq_hw_ctx_sysfs_entry *entry;
 103         struct blk_mq_hw_ctx *hctx;
 104         struct request_queue *q;
 105         ssize_t res;
 106
 107         entry = container_of(attr, struct blk_mq_hw_ctx_sysfs_entry, attr);
 108         hctx = container_of(kobj, struct blk_mq_hw_ctx, kobj);
 109         q = hctx->queue;
 110
 111         if (!entry->show)
 112                 return -EIO;
 113
 114         res = -ENOENT;
 115         mutex_lock(&q->sysfs_lock);
 116         if (!blk_queue_dying(q))
 117                 res = entry->show(hctx, page);
 118         mutex_unlock(&q->sysfs_lock);
 119         return res;
 120 }
 121
 122 static ssize_t blk_mq_hw_sysfs_store(struct kobject *kobj,
 123                                      struct attribute *attr, const char *page,
 124                                      size_t length)
 125 {
 126         struct blk_mq_hw_ctx_sysfs_entry *entry;
 127         struct blk_mq_hw_ctx *hctx;
 128         struct request_queue *q;
 129         ssize_t res;
 130
 131         entry = container_of(attr, struct blk_mq_hw_ctx_sysfs_entry, attr);
 132         hctx = container_of(kobj, struct blk_mq_hw_ctx, kobj);
 133         q = hctx->queue;
 134
 135         if (!entry->store)
 136                 return -EIO;
 137
 138         res = -ENOENT;
 139         mutex_lock(&q->sysfs_lock);
 140         if (!blk_queue_dying(q))
 141                 res = entry->store(hctx, page, length);
 142         mutex_unlock(&q->sysfs_lock);
 143         return res;
 144 }
 145
 146 static ssize_t blk_mq_hw_sysfs_nr_tags_show(struct blk_mq_hw_ctx *hctx,
 147                                             char *page)
 148 {
 149         return sprintf(page, "%u\n", hctx->tags->nr_tags);
 150 }
 151
 152 static ssize_t blk_mq_hw_sysfs_nr_reserved_tags_show(struct blk_mq_hw_ctx *hctx,
 153                                                      char *page)
 154 {
 155         return sprintf(page, "%u\n", hctx->tags->nr_reserved_tags);
 156 }
 157
 158 static ssize_t blk_mq_hw_sysfs_cpus_show(struct blk_mq_hw_ctx *hctx, char *page)
 159 {
 160         unsigned int i, first = 1;
 161         ssize_t ret = 0;
 162
 163         for_each_cpu(i, hctx->cpumask) {
 164                 if (first)
 165                         ret += sprintf(ret + page, "%u", i);
 166                 else
 167                         ret += sprintf(ret + page, ", %u", i);
 168
 169                 first = 0;
 170         }
 171
 172         ret += sprintf(ret + page, "\n");
 173         return ret;
 174 }
 175
 176 static struct attribute *default_ctx_attrs[] = {
 177         NULL,
 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
 200 static const struct sysfs_ops blk_mq_sysfs_ops = {
 201         .show   = blk_mq_sysfs_show,
 202         .store  = blk_mq_sysfs_store,
 203 };
 204
 205 static const struct sysfs_ops blk_mq_hw_sysfs_ops = {
 206         .show   = blk_mq_hw_sysfs_show,
 207         .store  = blk_mq_hw_sysfs_store,
 208 };
 209
 210 static struct kobj_type blk_mq_ktype = {
 211         .sysfs_ops      = &blk_mq_sysfs_ops,
 212         .release        = blk_mq_sysfs_release,
 213 };
 214
 215 static struct kobj_type blk_mq_ctx_ktype = {
 216         .sysfs_ops      = &blk_mq_sysfs_ops,
 217         .default_attrs  = default_ctx_attrs,
 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_attrs  = default_hw_ctx_attrs,
 224         .release        = blk_mq_hw_sysfs_release,
 225 };
 226
 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
 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
 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_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
 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
 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
 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
 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_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
 347 int blk_mq_register_dev(struct device *dev, struct request_queue *q)
 348 {
 349         int ret;
 350
 351         mutex_lock(&q->sysfs_lock);
 352         ret = __blk_mq_register_dev(dev, q);
 353         mutex_unlock(&q->sysfs_lock);
 354
 355         return ret;
 356 }
 357
 358 void blk_mq_sysfs_unregister(struct request_queue *q)
 359 {
 360         struct blk_mq_hw_ctx *hctx;
 361         int i;
 362
 363         mutex_lock(&q->sysfs_lock);
 364         if (!q->mq_sysfs_init_done)
 365                 goto unlock;
 366
 367         queue_for_each_hw_ctx(q, hctx, i)
 368                 blk_mq_unregister_hctx(hctx);
 369
 370 unlock:
 371         mutex_unlock(&q->sysfs_lock);
 372 }
 373
 374 int blk_mq_sysfs_register(struct request_queue *q)
 375 {
 376         struct blk_mq_hw_ctx *hctx;
 377         int i, ret = 0;
 378
 379         mutex_lock(&q->sysfs_lock);
 380         if (!q->mq_sysfs_init_done)
 381                 goto unlock;
 382
 383         queue_for_each_hw_ctx(q, hctx, i) {
 384                 ret = blk_mq_register_hctx(hctx);
 385                 if (ret)
 386                         break;
 387         }
 388
 389 unlock:
 390         mutex_unlock(&q->sysfs_lock);
 391
 392         return ret;
 393 }