arm: tegra: enterprise: Controls for 3d barrier
[linux-2.6.git] / block / blk-sysfs.c
1 /*
2  * Functions related to sysfs handling
3  */
4 #include <linux/kernel.h>
5 #include <linux/slab.h>
6 #include <linux/module.h>
7 #include <linux/bio.h>
8 #include <linux/blkdev.h>
9 #include <linux/blktrace_api.h>
10
11 #include "blk.h"
12
13 struct queue_sysfs_entry {
14         struct attribute attr;
15         ssize_t (*show)(struct request_queue *, char *);
16         ssize_t (*store)(struct request_queue *, const char *, size_t);
17 };
18
19 static ssize_t
20 queue_var_show(unsigned long var, char *page)
21 {
22         return sprintf(page, "%lu\n", var);
23 }
24
25 static ssize_t
26 queue_var_store(unsigned long *var, const char *page, size_t count)
27 {
28         char *p = (char *) page;
29
30         *var = simple_strtoul(p, &p, 10);
31         return count;
32 }
33
34 static ssize_t queue_requests_show(struct request_queue *q, char *page)
35 {
36         return queue_var_show(q->nr_requests, (page));
37 }
38
39 static ssize_t
40 queue_requests_store(struct request_queue *q, const char *page, size_t count)
41 {
42         struct request_list *rl = &q->rq;
43         unsigned long nr;
44         int ret;
45
46         if (!q->request_fn)
47                 return -EINVAL;
48
49         ret = queue_var_store(&nr, page, count);
50         if (nr < BLKDEV_MIN_RQ)
51                 nr = BLKDEV_MIN_RQ;
52
53         spin_lock_irq(q->queue_lock);
54         q->nr_requests = nr;
55         blk_queue_congestion_threshold(q);
56
57         if (rl->count[BLK_RW_SYNC] >= queue_congestion_on_threshold(q))
58                 blk_set_queue_congested(q, BLK_RW_SYNC);
59         else if (rl->count[BLK_RW_SYNC] < queue_congestion_off_threshold(q))
60                 blk_clear_queue_congested(q, BLK_RW_SYNC);
61
62         if (rl->count[BLK_RW_ASYNC] >= queue_congestion_on_threshold(q))
63                 blk_set_queue_congested(q, BLK_RW_ASYNC);
64         else if (rl->count[BLK_RW_ASYNC] < queue_congestion_off_threshold(q))
65                 blk_clear_queue_congested(q, BLK_RW_ASYNC);
66
67         if (rl->count[BLK_RW_SYNC] >= q->nr_requests) {
68                 blk_set_queue_full(q, BLK_RW_SYNC);
69         } else {
70                 blk_clear_queue_full(q, BLK_RW_SYNC);
71                 wake_up(&rl->wait[BLK_RW_SYNC]);
72         }
73
74         if (rl->count[BLK_RW_ASYNC] >= q->nr_requests) {
75                 blk_set_queue_full(q, BLK_RW_ASYNC);
76         } else {
77                 blk_clear_queue_full(q, BLK_RW_ASYNC);
78                 wake_up(&rl->wait[BLK_RW_ASYNC]);
79         }
80         spin_unlock_irq(q->queue_lock);
81         return ret;
82 }
83
84 static ssize_t queue_ra_show(struct request_queue *q, char *page)
85 {
86         unsigned long ra_kb = q->backing_dev_info.ra_pages <<
87                                         (PAGE_CACHE_SHIFT - 10);
88
89         return queue_var_show(ra_kb, (page));
90 }
91
92 static ssize_t
93 queue_ra_store(struct request_queue *q, const char *page, size_t count)
94 {
95         unsigned long ra_kb;
96         ssize_t ret = queue_var_store(&ra_kb, page, count);
97
98         q->backing_dev_info.ra_pages = ra_kb >> (PAGE_CACHE_SHIFT - 10);
99
100         return ret;
101 }
102
103 static ssize_t queue_max_sectors_show(struct request_queue *q, char *page)
104 {
105         int max_sectors_kb = queue_max_sectors(q) >> 1;
106
107         return queue_var_show(max_sectors_kb, (page));
108 }
109
110 static ssize_t queue_max_segments_show(struct request_queue *q, char *page)
111 {
112         return queue_var_show(queue_max_segments(q), (page));
113 }
114
115 static ssize_t queue_max_integrity_segments_show(struct request_queue *q, char *page)
116 {
117         return queue_var_show(q->limits.max_integrity_segments, (page));
118 }
119
120 static ssize_t queue_max_segment_size_show(struct request_queue *q, char *page)
121 {
122         if (blk_queue_cluster(q))
123                 return queue_var_show(queue_max_segment_size(q), (page));
124
125         return queue_var_show(PAGE_CACHE_SIZE, (page));
126 }
127
128 static ssize_t queue_logical_block_size_show(struct request_queue *q, char *page)
129 {
130         return queue_var_show(queue_logical_block_size(q), page);
131 }
132
133 static ssize_t queue_physical_block_size_show(struct request_queue *q, char *page)
134 {
135         return queue_var_show(queue_physical_block_size(q), page);
136 }
137
138 static ssize_t queue_io_min_show(struct request_queue *q, char *page)
139 {
140         return queue_var_show(queue_io_min(q), page);
141 }
142
143 static ssize_t queue_io_opt_show(struct request_queue *q, char *page)
144 {
145         return queue_var_show(queue_io_opt(q), page);
146 }
147
148 static ssize_t queue_discard_granularity_show(struct request_queue *q, char *page)
149 {
150         return queue_var_show(q->limits.discard_granularity, page);
151 }
152
153 static ssize_t queue_discard_max_show(struct request_queue *q, char *page)
154 {
155         return sprintf(page, "%llu\n",
156                        (unsigned long long)q->limits.max_discard_sectors << 9);
157 }
158
159 static ssize_t queue_discard_zeroes_data_show(struct request_queue *q, char *page)
160 {
161         return queue_var_show(queue_discard_zeroes_data(q), page);
162 }
163
164 static ssize_t
165 queue_max_sectors_store(struct request_queue *q, const char *page, size_t count)
166 {
167         unsigned long max_sectors_kb,
168                 max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1,
169                         page_kb = 1 << (PAGE_CACHE_SHIFT - 10);
170         ssize_t ret = queue_var_store(&max_sectors_kb, page, count);
171
172         if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb)
173                 return -EINVAL;
174
175         spin_lock_irq(q->queue_lock);
176         q->limits.max_sectors = max_sectors_kb << 1;
177         spin_unlock_irq(q->queue_lock);
178
179         return ret;
180 }
181
182 static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page)
183 {
184         int max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1;
185
186         return queue_var_show(max_hw_sectors_kb, (page));
187 }
188
189 #define QUEUE_SYSFS_BIT_FNS(name, flag, neg)                            \
190 static ssize_t                                                          \
191 queue_show_##name(struct request_queue *q, char *page)                  \
192 {                                                                       \
193         int bit;                                                        \
194         bit = test_bit(QUEUE_FLAG_##flag, &q->queue_flags);             \
195         return queue_var_show(neg ? !bit : bit, page);                  \
196 }                                                                       \
197 static ssize_t                                                          \
198 queue_store_##name(struct request_queue *q, const char *page, size_t count) \
199 {                                                                       \
200         unsigned long val;                                              \
201         ssize_t ret;                                                    \
202         ret = queue_var_store(&val, page, count);                       \
203         if (neg)                                                        \
204                 val = !val;                                             \
205                                                                         \
206         spin_lock_irq(q->queue_lock);                                   \
207         if (val)                                                        \
208                 queue_flag_set(QUEUE_FLAG_##flag, q);                   \
209         else                                                            \
210                 queue_flag_clear(QUEUE_FLAG_##flag, q);                 \
211         spin_unlock_irq(q->queue_lock);                                 \
212         return ret;                                                     \
213 }
214
215 QUEUE_SYSFS_BIT_FNS(nonrot, NONROT, 1);
216 QUEUE_SYSFS_BIT_FNS(random, ADD_RANDOM, 0);
217 QUEUE_SYSFS_BIT_FNS(iostats, IO_STAT, 0);
218 #undef QUEUE_SYSFS_BIT_FNS
219
220 static ssize_t queue_nomerges_show(struct request_queue *q, char *page)
221 {
222         return queue_var_show((blk_queue_nomerges(q) << 1) |
223                                blk_queue_noxmerges(q), page);
224 }
225
226 static ssize_t queue_nomerges_store(struct request_queue *q, const char *page,
227                                     size_t count)
228 {
229         unsigned long nm;
230         ssize_t ret = queue_var_store(&nm, page, count);
231
232         spin_lock_irq(q->queue_lock);
233         queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
234         queue_flag_clear(QUEUE_FLAG_NOXMERGES, q);
235         if (nm == 2)
236                 queue_flag_set(QUEUE_FLAG_NOMERGES, q);
237         else if (nm)
238                 queue_flag_set(QUEUE_FLAG_NOXMERGES, q);
239         spin_unlock_irq(q->queue_lock);
240
241         return ret;
242 }
243
244 static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page)
245 {
246         bool set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags);
247         bool force = test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags);
248
249         return queue_var_show(set << force, page);
250 }
251
252 static ssize_t
253 queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count)
254 {
255         ssize_t ret = -EINVAL;
256 #if defined(CONFIG_USE_GENERIC_SMP_HELPERS)
257         unsigned long val;
258
259         ret = queue_var_store(&val, page, count);
260         spin_lock_irq(q->queue_lock);
261         if (val == 2) {
262                 queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
263                 queue_flag_set(QUEUE_FLAG_SAME_FORCE, q);
264         } else if (val == 1) {
265                 queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
266                 queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
267         } else if (val == 0) {
268                 queue_flag_clear(QUEUE_FLAG_SAME_COMP, q);
269                 queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
270         }
271         spin_unlock_irq(q->queue_lock);
272 #endif
273         return ret;
274 }
275
276 static struct queue_sysfs_entry queue_requests_entry = {
277         .attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR },
278         .show = queue_requests_show,
279         .store = queue_requests_store,
280 };
281
282 static struct queue_sysfs_entry queue_ra_entry = {
283         .attr = {.name = "read_ahead_kb", .mode = S_IRUGO | S_IWUSR },
284         .show = queue_ra_show,
285         .store = queue_ra_store,
286 };
287
288 static struct queue_sysfs_entry queue_max_sectors_entry = {
289         .attr = {.name = "max_sectors_kb", .mode = S_IRUGO | S_IWUSR },
290         .show = queue_max_sectors_show,
291         .store = queue_max_sectors_store,
292 };
293
294 static struct queue_sysfs_entry queue_max_hw_sectors_entry = {
295         .attr = {.name = "max_hw_sectors_kb", .mode = S_IRUGO },
296         .show = queue_max_hw_sectors_show,
297 };
298
299 static struct queue_sysfs_entry queue_max_segments_entry = {
300         .attr = {.name = "max_segments", .mode = S_IRUGO },
301         .show = queue_max_segments_show,
302 };
303
304 static struct queue_sysfs_entry queue_max_integrity_segments_entry = {
305         .attr = {.name = "max_integrity_segments", .mode = S_IRUGO },
306         .show = queue_max_integrity_segments_show,
307 };
308
309 static struct queue_sysfs_entry queue_max_segment_size_entry = {
310         .attr = {.name = "max_segment_size", .mode = S_IRUGO },
311         .show = queue_max_segment_size_show,
312 };
313
314 static struct queue_sysfs_entry queue_iosched_entry = {
315         .attr = {.name = "scheduler", .mode = S_IRUGO | S_IWUSR },
316         .show = elv_iosched_show,
317         .store = elv_iosched_store,
318 };
319
320 static struct queue_sysfs_entry queue_hw_sector_size_entry = {
321         .attr = {.name = "hw_sector_size", .mode = S_IRUGO },
322         .show = queue_logical_block_size_show,
323 };
324
325 static struct queue_sysfs_entry queue_logical_block_size_entry = {
326         .attr = {.name = "logical_block_size", .mode = S_IRUGO },
327         .show = queue_logical_block_size_show,
328 };
329
330 static struct queue_sysfs_entry queue_physical_block_size_entry = {
331         .attr = {.name = "physical_block_size", .mode = S_IRUGO },
332         .show = queue_physical_block_size_show,
333 };
334
335 static struct queue_sysfs_entry queue_io_min_entry = {
336         .attr = {.name = "minimum_io_size", .mode = S_IRUGO },
337         .show = queue_io_min_show,
338 };
339
340 static struct queue_sysfs_entry queue_io_opt_entry = {
341         .attr = {.name = "optimal_io_size", .mode = S_IRUGO },
342         .show = queue_io_opt_show,
343 };
344
345 static struct queue_sysfs_entry queue_discard_granularity_entry = {
346         .attr = {.name = "discard_granularity", .mode = S_IRUGO },
347         .show = queue_discard_granularity_show,
348 };
349
350 static struct queue_sysfs_entry queue_discard_max_entry = {
351         .attr = {.name = "discard_max_bytes", .mode = S_IRUGO },
352         .show = queue_discard_max_show,
353 };
354
355 static struct queue_sysfs_entry queue_discard_zeroes_data_entry = {
356         .attr = {.name = "discard_zeroes_data", .mode = S_IRUGO },
357         .show = queue_discard_zeroes_data_show,
358 };
359
360 static struct queue_sysfs_entry queue_nonrot_entry = {
361         .attr = {.name = "rotational", .mode = S_IRUGO | S_IWUSR },
362         .show = queue_show_nonrot,
363         .store = queue_store_nonrot,
364 };
365
366 static struct queue_sysfs_entry queue_nomerges_entry = {
367         .attr = {.name = "nomerges", .mode = S_IRUGO | S_IWUSR },
368         .show = queue_nomerges_show,
369         .store = queue_nomerges_store,
370 };
371
372 static struct queue_sysfs_entry queue_rq_affinity_entry = {
373         .attr = {.name = "rq_affinity", .mode = S_IRUGO | S_IWUSR },
374         .show = queue_rq_affinity_show,
375         .store = queue_rq_affinity_store,
376 };
377
378 static struct queue_sysfs_entry queue_iostats_entry = {
379         .attr = {.name = "iostats", .mode = S_IRUGO | S_IWUSR },
380         .show = queue_show_iostats,
381         .store = queue_store_iostats,
382 };
383
384 static struct queue_sysfs_entry queue_random_entry = {
385         .attr = {.name = "add_random", .mode = S_IRUGO | S_IWUSR },
386         .show = queue_show_random,
387         .store = queue_store_random,
388 };
389
390 static struct attribute *default_attrs[] = {
391         &queue_requests_entry.attr,
392         &queue_ra_entry.attr,
393         &queue_max_hw_sectors_entry.attr,
394         &queue_max_sectors_entry.attr,
395         &queue_max_segments_entry.attr,
396         &queue_max_integrity_segments_entry.attr,
397         &queue_max_segment_size_entry.attr,
398         &queue_iosched_entry.attr,
399         &queue_hw_sector_size_entry.attr,
400         &queue_logical_block_size_entry.attr,
401         &queue_physical_block_size_entry.attr,
402         &queue_io_min_entry.attr,
403         &queue_io_opt_entry.attr,
404         &queue_discard_granularity_entry.attr,
405         &queue_discard_max_entry.attr,
406         &queue_discard_zeroes_data_entry.attr,
407         &queue_nonrot_entry.attr,
408         &queue_nomerges_entry.attr,
409         &queue_rq_affinity_entry.attr,
410         &queue_iostats_entry.attr,
411         &queue_random_entry.attr,
412         NULL,
413 };
414
415 #define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr)
416
417 static ssize_t
418 queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
419 {
420         struct queue_sysfs_entry *entry = to_queue(attr);
421         struct request_queue *q =
422                 container_of(kobj, struct request_queue, kobj);
423         ssize_t res;
424
425         if (!entry->show)
426                 return -EIO;
427         mutex_lock(&q->sysfs_lock);
428         if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)) {
429                 mutex_unlock(&q->sysfs_lock);
430                 return -ENOENT;
431         }
432         res = entry->show(q, page);
433         mutex_unlock(&q->sysfs_lock);
434         return res;
435 }
436
437 static ssize_t
438 queue_attr_store(struct kobject *kobj, struct attribute *attr,
439                     const char *page, size_t length)
440 {
441         struct queue_sysfs_entry *entry = to_queue(attr);
442         struct request_queue *q;
443         ssize_t res;
444
445         if (!entry->store)
446                 return -EIO;
447
448         q = container_of(kobj, struct request_queue, kobj);
449         mutex_lock(&q->sysfs_lock);
450         if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)) {
451                 mutex_unlock(&q->sysfs_lock);
452                 return -ENOENT;
453         }
454         res = entry->store(q, page, length);
455         mutex_unlock(&q->sysfs_lock);
456         return res;
457 }
458
459 /**
460  * blk_cleanup_queue: - release a &struct request_queue when it is no longer needed
461  * @kobj:    the kobj belonging of the request queue to be released
462  *
463  * Description:
464  *     blk_cleanup_queue is the pair to blk_init_queue() or
465  *     blk_queue_make_request().  It should be called when a request queue is
466  *     being released; typically when a block device is being de-registered.
467  *     Currently, its primary task it to free all the &struct request
468  *     structures that were allocated to the queue and the queue itself.
469  *
470  * Caveat:
471  *     Hopefully the low level driver will have finished any
472  *     outstanding requests first...
473  **/
474 static void blk_release_queue(struct kobject *kobj)
475 {
476         struct request_queue *q =
477                 container_of(kobj, struct request_queue, kobj);
478         struct request_list *rl = &q->rq;
479
480         blk_sync_queue(q);
481
482         if (q->elevator)
483                 elevator_exit(q->elevator);
484
485         blk_throtl_exit(q);
486
487         if (rl->rq_pool)
488                 mempool_destroy(rl->rq_pool);
489
490         if (q->queue_tags)
491                 __blk_queue_free_tags(q);
492
493         blk_trace_shutdown(q);
494
495         bdi_destroy(&q->backing_dev_info);
496         kmem_cache_free(blk_requestq_cachep, q);
497 }
498
499 static const struct sysfs_ops queue_sysfs_ops = {
500         .show   = queue_attr_show,
501         .store  = queue_attr_store,
502 };
503
504 struct kobj_type blk_queue_ktype = {
505         .sysfs_ops      = &queue_sysfs_ops,
506         .default_attrs  = default_attrs,
507         .release        = blk_release_queue,
508 };
509
510 int blk_register_queue(struct gendisk *disk)
511 {
512         int ret;
513         struct device *dev = disk_to_dev(disk);
514         struct request_queue *q = disk->queue;
515
516         if (WARN_ON(!q))
517                 return -ENXIO;
518
519         ret = blk_trace_init_sysfs(dev);
520         if (ret)
521                 return ret;
522
523         ret = kobject_add(&q->kobj, kobject_get(&dev->kobj), "%s", "queue");
524         if (ret < 0) {
525                 blk_trace_remove_sysfs(dev);
526                 return ret;
527         }
528
529         kobject_uevent(&q->kobj, KOBJ_ADD);
530
531         if (!q->request_fn)
532                 return 0;
533
534         ret = elv_register_queue(q);
535         if (ret) {
536                 kobject_uevent(&q->kobj, KOBJ_REMOVE);
537                 kobject_del(&q->kobj);
538                 blk_trace_remove_sysfs(dev);
539                 kobject_put(&dev->kobj);
540                 return ret;
541         }
542
543         return 0;
544 }
545
546 void blk_unregister_queue(struct gendisk *disk)
547 {
548         struct request_queue *q = disk->queue;
549
550         if (WARN_ON(!q))
551                 return;
552
553         if (q->request_fn)
554                 elv_unregister_queue(q);
555
556         kobject_uevent(&q->kobj, KOBJ_REMOVE);
557         kobject_del(&q->kobj);
558         blk_trace_remove_sysfs(disk_to_dev(disk));
559         kobject_put(&disk_to_dev(disk)->kobj);
560 }