Blame view
block/blk-tag.c
10 KB
b24413180 License cleanup: ... |
1 |
// SPDX-License-Identifier: GPL-2.0 |
8324aa91d block: split tag ... |
2 3 4 5 6 7 8 |
/* * Functions related to tagged command queuing */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/bio.h> #include <linux/blkdev.h> |
5a0e3ad6a include cleanup: ... |
9 |
#include <linux/slab.h> |
8324aa91d block: split tag ... |
10 |
|
278caf012 block/blk-tag.c s... |
11 |
#include "blk.h" |
8324aa91d block: split tag ... |
12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 |
/** * blk_queue_find_tag - find a request by its tag and queue * @q: The request queue for the device * @tag: The tag of the request * * Notes: * Should be used when a device returns a tag and you want to match * it with a request. * * no locks need be held. **/ struct request *blk_queue_find_tag(struct request_queue *q, int tag) { return blk_map_queue_find_tag(q->queue_tags, tag); } |
8324aa91d block: split tag ... |
27 28 29 |
EXPORT_SYMBOL(blk_queue_find_tag); /** |
d45b3279a block: don't assu... |
30 |
* blk_free_tags - release a given set of tag maintenance info |
8324aa91d block: split tag ... |
31 32 |
* @bqt: the tag map to free * |
d45b3279a block: don't assu... |
33 34 |
* Drop the reference count on @bqt and frees it when the last reference * is dropped. |
8324aa91d block: split tag ... |
35 |
*/ |
d45b3279a block: don't assu... |
36 |
void blk_free_tags(struct blk_queue_tag *bqt) |
8324aa91d block: split tag ... |
37 |
{ |
d45b3279a block: don't assu... |
38 |
if (atomic_dec_and_test(&bqt->refcnt)) { |
0e3eb45e4 block: remove unu... |
39 40 |
BUG_ON(find_first_bit(bqt->tag_map, bqt->max_depth) < bqt->max_depth); |
8324aa91d block: split tag ... |
41 42 43 44 45 46 47 48 49 |
kfree(bqt->tag_index); bqt->tag_index = NULL; kfree(bqt->tag_map); bqt->tag_map = NULL; kfree(bqt); } |
8324aa91d block: split tag ... |
50 |
} |
d45b3279a block: don't assu... |
51 |
EXPORT_SYMBOL(blk_free_tags); |
8324aa91d block: split tag ... |
52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 |
/** * __blk_queue_free_tags - release tag maintenance info * @q: the request queue for the device * * Notes: * blk_cleanup_queue() will take care of calling this function, if tagging * has been used. So there's no need to call this directly. **/ void __blk_queue_free_tags(struct request_queue *q) { struct blk_queue_tag *bqt = q->queue_tags; if (!bqt) return; |
d45b3279a block: don't assu... |
67 |
blk_free_tags(bqt); |
8324aa91d block: split tag ... |
68 69 |
q->queue_tags = NULL; |
aa94b5371 block: adjust tag... |
70 |
queue_flag_clear_unlocked(QUEUE_FLAG_QUEUED, q); |
8324aa91d block: split tag ... |
71 72 73 |
} /** |
8324aa91d block: split tag ... |
74 75 76 77 |
* blk_queue_free_tags - release tag maintenance info * @q: the request queue for the device * * Notes: |
710027a48 Add some block/ s... |
78 |
* This is used to disable tagged queuing to a device, yet leave |
8324aa91d block: split tag ... |
79 80 81 82 |
* queue in function. **/ void blk_queue_free_tags(struct request_queue *q) { |
aa94b5371 block: adjust tag... |
83 |
queue_flag_clear_unlocked(QUEUE_FLAG_QUEUED, q); |
8324aa91d block: split tag ... |
84 |
} |
8324aa91d block: split tag ... |
85 86 87 88 89 90 91 92 93 94 95 96 97 |
EXPORT_SYMBOL(blk_queue_free_tags); static int init_tag_map(struct request_queue *q, struct blk_queue_tag *tags, int depth) { struct request **tag_index; unsigned long *tag_map; int nr_ulongs; if (q && depth > q->nr_requests * 2) { depth = q->nr_requests * 2; printk(KERN_ERR "%s: adjusted depth to %d ", |
24c03d47d block: remove rem... |
98 |
__func__, depth); |
8324aa91d block: split tag ... |
99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 |
} tag_index = kzalloc(depth * sizeof(struct request *), GFP_ATOMIC); if (!tag_index) goto fail; nr_ulongs = ALIGN(depth, BITS_PER_LONG) / BITS_PER_LONG; tag_map = kzalloc(nr_ulongs * sizeof(unsigned long), GFP_ATOMIC); if (!tag_map) goto fail; tags->real_max_depth = depth; tags->max_depth = depth; tags->tag_index = tag_index; tags->tag_map = tag_map; return 0; fail: kfree(tag_index); return -ENOMEM; } static struct blk_queue_tag *__blk_queue_init_tags(struct request_queue *q, |
ee1b6f7af block: support di... |
122 |
int depth, int alloc_policy) |
8324aa91d block: split tag ... |
123 124 125 126 127 128 129 130 131 |
{ struct blk_queue_tag *tags; tags = kmalloc(sizeof(struct blk_queue_tag), GFP_ATOMIC); if (!tags) goto fail; if (init_tag_map(q, tags, depth)) goto fail; |
8324aa91d block: split tag ... |
132 |
atomic_set(&tags->refcnt, 1); |
ee1b6f7af block: support di... |
133 134 |
tags->alloc_policy = alloc_policy; tags->next_tag = 0; |
8324aa91d block: split tag ... |
135 136 137 138 139 140 141 142 143 |
return tags; fail: kfree(tags); return NULL; } /** * blk_init_tags - initialize the tag info for an external tag map * @depth: the maximum queue depth supported |
ee1b6f7af block: support di... |
144 |
* @alloc_policy: tag allocation policy |
8324aa91d block: split tag ... |
145 |
**/ |
ee1b6f7af block: support di... |
146 |
struct blk_queue_tag *blk_init_tags(int depth, int alloc_policy) |
8324aa91d block: split tag ... |
147 |
{ |
ee1b6f7af block: support di... |
148 |
return __blk_queue_init_tags(NULL, depth, alloc_policy); |
8324aa91d block: split tag ... |
149 150 151 152 153 154 155 156 |
} EXPORT_SYMBOL(blk_init_tags); /** * blk_queue_init_tags - initialize the queue tag info * @q: the request queue for the device * @depth: the maximum queue depth supported * @tags: the tag to use |
ee1b6f7af block: support di... |
157 |
* @alloc_policy: tag allocation policy |
aa94b5371 block: adjust tag... |
158 159 160 |
* * Queue lock must be held here if the function is called to resize an * existing map. |
8324aa91d block: split tag ... |
161 162 |
**/ int blk_queue_init_tags(struct request_queue *q, int depth, |
ee1b6f7af block: support di... |
163 |
struct blk_queue_tag *tags, int alloc_policy) |
8324aa91d block: split tag ... |
164 165 166 167 168 169 |
{ int rc; BUG_ON(tags && q->queue_tags && tags != q->queue_tags); if (!tags && !q->queue_tags) { |
ee1b6f7af block: support di... |
170 |
tags = __blk_queue_init_tags(q, depth, alloc_policy); |
8324aa91d block: split tag ... |
171 172 |
if (!tags) |
d41570b74 block/blk-tag.c: ... |
173 |
return -ENOMEM; |
8324aa91d block: split tag ... |
174 |
} else if (q->queue_tags) { |
6728cb0e6 block: make core ... |
175 176 |
rc = blk_queue_resize_tags(q, depth); if (rc) |
8324aa91d block: split tag ... |
177 |
return rc; |
75ad23bc0 block: make queue... |
178 |
queue_flag_set(QUEUE_FLAG_QUEUED, q); |
8324aa91d block: split tag ... |
179 180 181 182 183 184 185 186 |
return 0; } else atomic_inc(&tags->refcnt); /* * assign it, all done */ q->queue_tags = tags; |
aa94b5371 block: adjust tag... |
187 |
queue_flag_set_unlocked(QUEUE_FLAG_QUEUED, q); |
8324aa91d block: split tag ... |
188 189 |
INIT_LIST_HEAD(&q->tag_busy_list); return 0; |
8324aa91d block: split tag ... |
190 |
} |
8324aa91d block: split tag ... |
191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 |
EXPORT_SYMBOL(blk_queue_init_tags); /** * blk_queue_resize_tags - change the queueing depth * @q: the request queue for the device * @new_depth: the new max command queueing depth * * Notes: * Must be called with the queue lock held. **/ int blk_queue_resize_tags(struct request_queue *q, int new_depth) { struct blk_queue_tag *bqt = q->queue_tags; struct request **tag_index; unsigned long *tag_map; int max_depth, nr_ulongs; if (!bqt) return -ENXIO; /* * if we already have large enough real_max_depth. just * adjust max_depth. *NOTE* as requests with tag value * between new_depth and real_max_depth can be in-flight, tag * map can not be shrunk blindly here. */ if (new_depth <= bqt->real_max_depth) { bqt->max_depth = new_depth; return 0; } /* * Currently cannot replace a shared tag map with a new * one, so error out if this is the case */ if (atomic_read(&bqt->refcnt) != 1) return -EBUSY; /* * save the old state info, so we can copy it back */ tag_index = bqt->tag_index; tag_map = bqt->tag_map; max_depth = bqt->real_max_depth; if (init_tag_map(q, bqt, new_depth)) return -ENOMEM; memcpy(bqt->tag_index, tag_index, max_depth * sizeof(struct request *)); nr_ulongs = ALIGN(max_depth, BITS_PER_LONG) / BITS_PER_LONG; memcpy(bqt->tag_map, tag_map, nr_ulongs * sizeof(unsigned long)); kfree(tag_index); kfree(tag_map); return 0; } |
8324aa91d block: split tag ... |
247 248 249 250 251 252 253 254 |
EXPORT_SYMBOL(blk_queue_resize_tags); /** * blk_queue_end_tag - end tag operations for a request * @q: the request queue for the device * @rq: the request that has completed * * Description: |
710027a48 Add some block/ s... |
255 |
* Typically called when end_that_request_first() returns %0, meaning |
8324aa91d block: split tag ... |
256 257 258 |
* all transfers have been done for a request. It's important to call * this function before end_that_request_last(), as that will put the * request back on the free list thus corrupting the internal tag list. |
8324aa91d block: split tag ... |
259 260 261 262 |
**/ void blk_queue_end_tag(struct request_queue *q, struct request *rq) { struct blk_queue_tag *bqt = q->queue_tags; |
f2b20d436 block: fix blk_qu... |
263 |
unsigned tag = rq->tag; /* negative tags invalid */ |
8324aa91d block: split tag ... |
264 |
|
2fff8a924 block: Check lock... |
265 |
lockdep_assert_held(q->queue_lock); |
f2b20d436 block: fix blk_qu... |
266 |
BUG_ON(tag >= bqt->real_max_depth); |
8324aa91d block: split tag ... |
267 268 |
list_del_init(&rq->queuelist); |
e80640213 block: split out ... |
269 |
rq->rq_flags &= ~RQF_QUEUED; |
8324aa91d block: split tag ... |
270 |
rq->tag = -1; |
bd166ef18 blk-mq-sched: add... |
271 |
rq->internal_tag = -1; |
8324aa91d block: split tag ... |
272 273 274 275 |
if (unlikely(bqt->tag_index[tag] == NULL)) printk(KERN_ERR "%s: tag %d is missing ", |
24c03d47d block: remove rem... |
276 |
__func__, tag); |
8324aa91d block: split tag ... |
277 278 279 280 281 282 |
bqt->tag_index[tag] = NULL; if (unlikely(!test_bit(tag, bqt->tag_map))) { printk(KERN_ERR "%s: attempt to clear non-busy tag (%d) ", |
24c03d47d block: remove rem... |
283 |
__func__, tag); |
8324aa91d block: split tag ... |
284 285 286 287 288 289 290 |
return; } /* * The tag_map bit acts as a lock for tag_index[bit], so we need * unlock memory barrier semantics. */ clear_bit_unlock(tag, bqt->tag_map); |
8324aa91d block: split tag ... |
291 |
} |
8324aa91d block: split tag ... |
292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 |
/** * blk_queue_start_tag - find a free tag and assign it * @q: the request queue for the device * @rq: the block request that needs tagging * * Description: * This can either be used as a stand-alone helper, or possibly be * assigned as the queue &prep_rq_fn (in which case &struct request * automagically gets a tag assigned). Note that this function * assumes that any type of request can be queued! if this is not * true for your device, you must check the request type before * calling this function. The request will also be removed from * the request queue, so it's the drivers responsibility to readd * it if it should need to be restarted for some reason. |
8324aa91d block: split tag ... |
307 308 309 310 |
**/ int blk_queue_start_tag(struct request_queue *q, struct request *rq) { struct blk_queue_tag *bqt = q->queue_tags; |
0a7ae2ff0 block: change the... |
311 |
unsigned max_depth; |
8324aa91d block: split tag ... |
312 |
int tag; |
2fff8a924 block: Check lock... |
313 |
lockdep_assert_held(q->queue_lock); |
e80640213 block: split out ... |
314 |
if (unlikely((rq->rq_flags & RQF_QUEUED))) { |
6728cb0e6 block: make core ... |
315 |
printk(KERN_ERR |
8324aa91d block: split tag ... |
316 |
"%s: request %p for device [%s] already tagged %d", |
24c03d47d block: remove rem... |
317 |
__func__, rq, |
8324aa91d block: split tag ... |
318 319 320 321 322 323 324 |
rq->rq_disk ? rq->rq_disk->disk_name : "?", rq->tag); BUG(); } /* * Protect against shared tag maps, as we may not have exclusive * access to the tag map. |
e3ba9ae58 block: reserve so... |
325 326 327 |
* * We reserve a few tags just for sync IO, since we don't want * to starve sync IO on behalf of flooding async IO. |
8324aa91d block: split tag ... |
328 |
*/ |
e3ba9ae58 block: reserve so... |
329 |
max_depth = bqt->max_depth; |
0a7ae2ff0 block: change the... |
330 |
if (!rq_is_sync(rq) && max_depth > 1) { |
a6b3f7614 block: Reserve on... |
331 332 |
switch (max_depth) { case 2: |
0a7ae2ff0 block: change the... |
333 |
max_depth = 1; |
a6b3f7614 block: Reserve on... |
334 335 336 337 338 339 340 |
break; case 3: max_depth = 2; break; default: max_depth -= 2; } |
1b59dd511 block: use proper... |
341 |
if (q->in_flight[BLK_RW_ASYNC] > max_depth) |
0a7ae2ff0 block: change the... |
342 343 |
return 1; } |
e3ba9ae58 block: reserve so... |
344 |
|
8324aa91d block: split tag ... |
345 |
do { |
ee1b6f7af block: support di... |
346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 |
if (bqt->alloc_policy == BLK_TAG_ALLOC_FIFO) { tag = find_first_zero_bit(bqt->tag_map, max_depth); if (tag >= max_depth) return 1; } else { int start = bqt->next_tag; int size = min_t(int, bqt->max_depth, max_depth + start); tag = find_next_zero_bit(bqt->tag_map, size, start); if (tag >= size && start + size > bqt->max_depth) { size = start + size - bqt->max_depth; tag = find_first_zero_bit(bqt->tag_map, size); } if (tag >= size) return 1; } |
8324aa91d block: split tag ... |
361 362 363 364 365 366 |
} while (test_and_set_bit_lock(tag, bqt->tag_map)); /* * We need lock ordering semantics given by test_and_set_bit_lock. * See blk_queue_end_tag for details. */ |
ee1b6f7af block: support di... |
367 |
bqt->next_tag = (tag + 1) % bqt->max_depth; |
e80640213 block: split out ... |
368 |
rq->rq_flags |= RQF_QUEUED; |
8324aa91d block: split tag ... |
369 370 |
rq->tag = tag; bqt->tag_index[tag] = rq; |
9934c8c04 block: implement ... |
371 |
blk_start_request(rq); |
8324aa91d block: split tag ... |
372 |
list_add(&rq->queuelist, &q->tag_busy_list); |
8324aa91d block: split tag ... |
373 374 |
return 0; } |
8324aa91d block: split tag ... |
375 376 377 378 379 380 381 382 383 384 |
EXPORT_SYMBOL(blk_queue_start_tag); /** * blk_queue_invalidate_tags - invalidate all pending tags * @q: the request queue for the device * * Description: * Hardware conditions may dictate a need to stop all pending requests. * In this case, we will safely clear the block side of the tag queue and * readd all requests to the request queue in the right order. |
8324aa91d block: split tag ... |
385 386 387 388 |
**/ void blk_queue_invalidate_tags(struct request_queue *q) { struct list_head *tmp, *n; |
2fff8a924 block: Check lock... |
389 |
lockdep_assert_held(q->queue_lock); |
8324aa91d block: split tag ... |
390 391 392 |
list_for_each_safe(tmp, n, &q->tag_busy_list) blk_requeue_request(q, list_entry_rq(tmp)); } |
8324aa91d block: split tag ... |
393 |
EXPORT_SYMBOL(blk_queue_invalidate_tags); |