LXR linux/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
  16static void blk_mq_sysfs_release(struct kobject *kobj)
  17{
  18}
  19
  20static 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
  29struct 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
  35struct 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
  41static 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
  64static 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
  87static 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
 110static 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
 134static 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
 140static 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
 146static 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
 164static struct attribute *default_ctx_attrs[] = {
 165        NULL,
 166};
 167
 168static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_nr_tags = {
 169        .attr = {.name = "nr_tags", .mode = S_IRUGO },
 170        .show = blk_mq_hw_sysfs_nr_tags_show,
 171};
 172static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_nr_reserved_tags = {
 173        .attr = {.name = "nr_reserved_tags", .mode = S_IRUGO },
 174        .show = blk_mq_hw_sysfs_nr_reserved_tags_show,
 175};
 176static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_cpus = {
 177        .attr = {.name = "cpu_list", .mode = S_IRUGO },
 178        .show = blk_mq_hw_sysfs_cpus_show,
 179};
 180
 181static 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
 188static const struct sysfs_ops blk_mq_sysfs_ops = {
 189        .show   = blk_mq_sysfs_show,
 190        .store  = blk_mq_sysfs_store,
 191};
 192
 193static 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
 198static struct kobj_type blk_mq_ktype = {
 199        .sysfs_ops      = &blk_mq_sysfs_ops,
 200        .release        = blk_mq_sysfs_release,
 201};
 202
 203static 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
 209static 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
 215static 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
 229static 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
 251void 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
 268void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx)
 269{
 270        kobject_init(&hctx->kobj, &blk_mq_hw_ktype);
 271}
 272
 273void 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
 285void 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
 298int __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
 320out:
 321        return ret;
 322
 323unreg:
 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
 333int 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}
 343EXPORT_SYMBOL_GPL(blk_mq_register_dev);
 344
 345void 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
 357unlock:
 358        mutex_unlock(&q->sysfs_lock);
 359}
 360
 361int 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
 376unlock:
 377        mutex_unlock(&q->sysfs_lock);
 378
 379        return ret;
 380}
 381