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 blk_free_flush_queue(hctx->fq); 40 sbitmap_free(&hctx->ctx_map); 41 free_cpumask_var(hctx->cpumask); 42 kfree(hctx->ctxs); 43 kfree(hctx); 44 } 45 46 struct blk_mq_hw_ctx_sysfs_entry { 47 struct attribute attr; 48 ssize_t (*show)(struct blk_mq_hw_ctx *, char *); 49 ssize_t (*store)(struct blk_mq_hw_ctx *, const char *, size_t); 50 }; 51 52 static ssize_t blk_mq_hw_sysfs_show(struct kobject *kobj, 53 struct attribute *attr, char *page) 54 { 55 struct blk_mq_hw_ctx_sysfs_entry *entry; 56 struct blk_mq_hw_ctx *hctx; 57 struct request_queue *q; 58 ssize_t res; 59 60 entry = container_of(attr, struct blk_mq_hw_ctx_sysfs_entry, attr); 61 hctx = container_of(kobj, struct blk_mq_hw_ctx, kobj); 62 q = hctx->queue; 63 64 if (!entry->show) 65 return -EIO; 66 67 mutex_lock(&q->sysfs_lock); 68 res = entry->show(hctx, page); 69 mutex_unlock(&q->sysfs_lock); 70 return res; 71 } 72 73 static ssize_t blk_mq_hw_sysfs_store(struct kobject *kobj, 74 struct attribute *attr, const char *page, 75 size_t length) 76 { 77 struct blk_mq_hw_ctx_sysfs_entry *entry; 78 struct blk_mq_hw_ctx *hctx; 79 struct request_queue *q; 80 ssize_t res; 81 82 entry = container_of(attr, struct blk_mq_hw_ctx_sysfs_entry, attr); 83 hctx = container_of(kobj, struct blk_mq_hw_ctx, kobj); 84 q = hctx->queue; 85 86 if (!entry->store) 87 return -EIO; 88 89 mutex_lock(&q->sysfs_lock); 90 res = entry->store(hctx, page, length); 91 mutex_unlock(&q->sysfs_lock); 92 return res; 93 } 94 95 static ssize_t blk_mq_hw_sysfs_nr_tags_show(struct blk_mq_hw_ctx *hctx, 96 char *page) 97 { 98 return sprintf(page, "%u\n", hctx->tags->nr_tags); 99 } 100 101 static ssize_t blk_mq_hw_sysfs_nr_reserved_tags_show(struct blk_mq_hw_ctx *hctx, 102 char *page) 103 { 104 return sprintf(page, "%u\n", hctx->tags->nr_reserved_tags); 105 } 106 107 static ssize_t blk_mq_hw_sysfs_cpus_show(struct blk_mq_hw_ctx *hctx, char *page) 108 { 109 const size_t size = PAGE_SIZE - 1; 110 unsigned int i, first = 1; 111 int ret = 0, pos = 0; 112 113 for_each_cpu(i, hctx->cpumask) { 114 if (first) 115 ret = snprintf(pos + page, size - pos, "%u", i); 116 else 117 ret = snprintf(pos + page, size - pos, ", %u", i); 118 119 if (ret >= size - pos) 120 break; 121 122 first = 0; 123 pos += ret; 124 } 125 126 ret = snprintf(pos + page, size + 1 - pos, "\n"); 127 return pos + ret; 128 } 129 130 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_nr_tags = { 131 .attr = {.name = "nr_tags", .mode = 0444 }, 132 .show = blk_mq_hw_sysfs_nr_tags_show, 133 }; 134 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_nr_reserved_tags = { 135 .attr = {.name = "nr_reserved_tags", .mode = 0444 }, 136 .show = blk_mq_hw_sysfs_nr_reserved_tags_show, 137 }; 138 static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_cpus = { 139 .attr = {.name = "cpu_list", .mode = 0444 }, 140 .show = blk_mq_hw_sysfs_cpus_show, 141 }; 142 143 static struct attribute *default_hw_ctx_attrs[] = { 144 &blk_mq_hw_sysfs_nr_tags.attr, 145 &blk_mq_hw_sysfs_nr_reserved_tags.attr, 146 &blk_mq_hw_sysfs_cpus.attr, 147 NULL, 148 }; 149 ATTRIBUTE_GROUPS(default_hw_ctx); 150 151 static const struct sysfs_ops blk_mq_hw_sysfs_ops = { 152 .show = blk_mq_hw_sysfs_show, 153 .store = blk_mq_hw_sysfs_store, 154 }; 155 156 static struct kobj_type blk_mq_ktype = { 157 .release = blk_mq_sysfs_release, 158 }; 159 160 static struct kobj_type blk_mq_ctx_ktype = { 161 .release = blk_mq_ctx_sysfs_release, 162 }; 163 164 static struct kobj_type blk_mq_hw_ktype = { 165 .sysfs_ops = &blk_mq_hw_sysfs_ops, 166 .default_groups = default_hw_ctx_groups, 167 .release = blk_mq_hw_sysfs_release, 168 }; 169 170 static void blk_mq_unregister_hctx(struct blk_mq_hw_ctx *hctx) 171 { 172 struct blk_mq_ctx *ctx; 173 int i; 174 175 if (!hctx->nr_ctx) 176 return; 177 178 hctx_for_each_ctx(hctx, ctx, i) 179 kobject_del(&ctx->kobj); 180 181 kobject_del(&hctx->kobj); 182 } 183 184 static int blk_mq_register_hctx(struct blk_mq_hw_ctx *hctx) 185 { 186 struct request_queue *q = hctx->queue; 187 struct blk_mq_ctx *ctx; 188 int i, ret; 189 190 if (!hctx->nr_ctx) 191 return 0; 192 193 ret = kobject_add(&hctx->kobj, q->mq_kobj, "%u", hctx->queue_num); 194 if (ret) 195 return ret; 196 197 hctx_for_each_ctx(hctx, ctx, i) { 198 ret = kobject_add(&ctx->kobj, &hctx->kobj, "cpu%u", ctx->cpu); 199 if (ret) 200 break; 201 } 202 203 return ret; 204 } 205 206 void blk_mq_unregister_dev(struct device *dev, struct request_queue *q) 207 { 208 struct blk_mq_hw_ctx *hctx; 209 int i; 210 211 lockdep_assert_held(&q->sysfs_dir_lock); 212 213 queue_for_each_hw_ctx(q, hctx, i) 214 blk_mq_unregister_hctx(hctx); 215 216 kobject_uevent(q->mq_kobj, KOBJ_REMOVE); 217 kobject_del(q->mq_kobj); 218 kobject_put(&dev->kobj); 219 220 q->mq_sysfs_init_done = false; 221 } 222 223 void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx) 224 { 225 kobject_init(&hctx->kobj, &blk_mq_hw_ktype); 226 } 227 228 void blk_mq_sysfs_deinit(struct request_queue *q) 229 { 230 struct blk_mq_ctx *ctx; 231 int cpu; 232 233 for_each_possible_cpu(cpu) { 234 ctx = per_cpu_ptr(q->queue_ctx, cpu); 235 kobject_put(&ctx->kobj); 236 } 237 kobject_put(q->mq_kobj); 238 } 239 240 void blk_mq_sysfs_init(struct request_queue *q) 241 { 242 struct blk_mq_ctx *ctx; 243 int cpu; 244 245 kobject_init(q->mq_kobj, &blk_mq_ktype); 246 247 for_each_possible_cpu(cpu) { 248 ctx = per_cpu_ptr(q->queue_ctx, cpu); 249 250 kobject_get(q->mq_kobj); 251 kobject_init(&ctx->kobj, &blk_mq_ctx_ktype); 252 } 253 } 254 255 int __blk_mq_register_dev(struct device *dev, struct request_queue *q) 256 { 257 struct blk_mq_hw_ctx *hctx; 258 int ret, i; 259 260 WARN_ON_ONCE(!q->kobj.parent); 261 lockdep_assert_held(&q->sysfs_dir_lock); 262 263 ret = kobject_add(q->mq_kobj, kobject_get(&dev->kobj), "%s", "mq"); 264 if (ret < 0) 265 goto out; 266 267 kobject_uevent(q->mq_kobj, KOBJ_ADD); 268 269 queue_for_each_hw_ctx(q, hctx, i) { 270 ret = blk_mq_register_hctx(hctx); 271 if (ret) 272 goto unreg; 273 } 274 275 q->mq_sysfs_init_done = true; 276 277 out: 278 return ret; 279 280 unreg: 281 while (--i >= 0) 282 blk_mq_unregister_hctx(q->queue_hw_ctx[i]); 283 284 kobject_uevent(q->mq_kobj, KOBJ_REMOVE); 285 kobject_del(q->mq_kobj); 286 kobject_put(&dev->kobj); 287 return ret; 288 } 289 290 void blk_mq_sysfs_unregister(struct request_queue *q) 291 { 292 struct blk_mq_hw_ctx *hctx; 293 int i; 294 295 mutex_lock(&q->sysfs_dir_lock); 296 if (!q->mq_sysfs_init_done) 297 goto unlock; 298 299 queue_for_each_hw_ctx(q, hctx, i) 300 blk_mq_unregister_hctx(hctx); 301 302 unlock: 303 mutex_unlock(&q->sysfs_dir_lock); 304 } 305 306 int blk_mq_sysfs_register(struct request_queue *q) 307 { 308 struct blk_mq_hw_ctx *hctx; 309 int i, ret = 0; 310 311 mutex_lock(&q->sysfs_dir_lock); 312 if (!q->mq_sysfs_init_done) 313 goto unlock; 314 315 queue_for_each_hw_ctx(q, hctx, i) { 316 ret = blk_mq_register_hctx(hctx); 317 if (ret) 318 break; 319 } 320 321 unlock: 322 mutex_unlock(&q->sysfs_dir_lock); 323 324 return ret; 325 } 326