Commit | Line | Data |
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86db1e29 JA |
1 | /* |
2 | * Functions related to setting various queue properties from drivers | |
3 | */ | |
4 | #include <linux/kernel.h> | |
5 | #include <linux/module.h> | |
6 | #include <linux/init.h> | |
7 | #include <linux/bio.h> | |
8 | #include <linux/blkdev.h> | |
9 | #include <linux/bootmem.h> /* for max_pfn/max_low_pfn */ | |
70dd5bf3 | 10 | #include <linux/gcd.h> |
2cda2728 | 11 | #include <linux/lcm.h> |
ad5ebd2f | 12 | #include <linux/jiffies.h> |
5a0e3ad6 | 13 | #include <linux/gfp.h> |
86db1e29 JA |
14 | |
15 | #include "blk.h" | |
16 | ||
6728cb0e | 17 | unsigned long blk_max_low_pfn; |
86db1e29 | 18 | EXPORT_SYMBOL(blk_max_low_pfn); |
6728cb0e JA |
19 | |
20 | unsigned long blk_max_pfn; | |
86db1e29 JA |
21 | |
22 | /** | |
23 | * blk_queue_prep_rq - set a prepare_request function for queue | |
24 | * @q: queue | |
25 | * @pfn: prepare_request function | |
26 | * | |
27 | * It's possible for a queue to register a prepare_request callback which | |
28 | * is invoked before the request is handed to the request_fn. The goal of | |
29 | * the function is to prepare a request for I/O, it can be used to build a | |
30 | * cdb from the request data for instance. | |
31 | * | |
32 | */ | |
33 | void blk_queue_prep_rq(struct request_queue *q, prep_rq_fn *pfn) | |
34 | { | |
35 | q->prep_rq_fn = pfn; | |
36 | } | |
86db1e29 JA |
37 | EXPORT_SYMBOL(blk_queue_prep_rq); |
38 | ||
28018c24 JB |
39 | /** |
40 | * blk_queue_unprep_rq - set an unprepare_request function for queue | |
41 | * @q: queue | |
42 | * @ufn: unprepare_request function | |
43 | * | |
44 | * It's possible for a queue to register an unprepare_request callback | |
45 | * which is invoked before the request is finally completed. The goal | |
46 | * of the function is to deallocate any data that was allocated in the | |
47 | * prepare_request callback. | |
48 | * | |
49 | */ | |
50 | void blk_queue_unprep_rq(struct request_queue *q, unprep_rq_fn *ufn) | |
51 | { | |
52 | q->unprep_rq_fn = ufn; | |
53 | } | |
54 | EXPORT_SYMBOL(blk_queue_unprep_rq); | |
55 | ||
86db1e29 JA |
56 | void blk_queue_softirq_done(struct request_queue *q, softirq_done_fn *fn) |
57 | { | |
58 | q->softirq_done_fn = fn; | |
59 | } | |
86db1e29 JA |
60 | EXPORT_SYMBOL(blk_queue_softirq_done); |
61 | ||
242f9dcb JA |
62 | void blk_queue_rq_timeout(struct request_queue *q, unsigned int timeout) |
63 | { | |
64 | q->rq_timeout = timeout; | |
65 | } | |
66 | EXPORT_SYMBOL_GPL(blk_queue_rq_timeout); | |
67 | ||
68 | void blk_queue_rq_timed_out(struct request_queue *q, rq_timed_out_fn *fn) | |
69 | { | |
70 | q->rq_timed_out_fn = fn; | |
71 | } | |
72 | EXPORT_SYMBOL_GPL(blk_queue_rq_timed_out); | |
73 | ||
ef9e3fac KU |
74 | void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn) |
75 | { | |
76 | q->lld_busy_fn = fn; | |
77 | } | |
78 | EXPORT_SYMBOL_GPL(blk_queue_lld_busy); | |
79 | ||
e475bba2 MP |
80 | /** |
81 | * blk_set_default_limits - reset limits to default values | |
f740f5ca | 82 | * @lim: the queue_limits structure to reset |
e475bba2 MP |
83 | * |
84 | * Description: | |
b1bd055d | 85 | * Returns a queue_limit struct to its default state. |
e475bba2 MP |
86 | */ |
87 | void blk_set_default_limits(struct queue_limits *lim) | |
88 | { | |
8a78362c | 89 | lim->max_segments = BLK_MAX_SEGMENTS; |
13f05c8d | 90 | lim->max_integrity_segments = 0; |
e475bba2 | 91 | lim->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK; |
03100aad | 92 | lim->virt_boundary_mask = 0; |
eb28d31b | 93 | lim->max_segment_size = BLK_MAX_SEGMENT_SIZE; |
b1bd055d | 94 | lim->max_sectors = lim->max_hw_sectors = BLK_SAFE_MAX_SECTORS; |
762380ad | 95 | lim->chunk_sectors = 0; |
4363ac7c | 96 | lim->max_write_same_sectors = 0; |
86b37281 | 97 | lim->max_discard_sectors = 0; |
0034af03 | 98 | lim->max_hw_discard_sectors = 0; |
86b37281 MP |
99 | lim->discard_granularity = 0; |
100 | lim->discard_alignment = 0; | |
101 | lim->discard_misaligned = 0; | |
b1bd055d | 102 | lim->discard_zeroes_data = 0; |
e475bba2 | 103 | lim->logical_block_size = lim->physical_block_size = lim->io_min = 512; |
3a02c8e8 | 104 | lim->bounce_pfn = (unsigned long)(BLK_BOUNCE_ANY >> PAGE_SHIFT); |
e475bba2 MP |
105 | lim->alignment_offset = 0; |
106 | lim->io_opt = 0; | |
107 | lim->misaligned = 0; | |
e692cb66 | 108 | lim->cluster = 1; |
e475bba2 MP |
109 | } |
110 | EXPORT_SYMBOL(blk_set_default_limits); | |
111 | ||
b1bd055d MP |
112 | /** |
113 | * blk_set_stacking_limits - set default limits for stacking devices | |
114 | * @lim: the queue_limits structure to reset | |
115 | * | |
116 | * Description: | |
117 | * Returns a queue_limit struct to its default state. Should be used | |
118 | * by stacking drivers like DM that have no internal limits. | |
119 | */ | |
120 | void blk_set_stacking_limits(struct queue_limits *lim) | |
121 | { | |
122 | blk_set_default_limits(lim); | |
123 | ||
124 | /* Inherit limits from component devices */ | |
125 | lim->discard_zeroes_data = 1; | |
126 | lim->max_segments = USHRT_MAX; | |
127 | lim->max_hw_sectors = UINT_MAX; | |
d82ae52e | 128 | lim->max_segment_size = UINT_MAX; |
fe86cdce | 129 | lim->max_sectors = UINT_MAX; |
4363ac7c | 130 | lim->max_write_same_sectors = UINT_MAX; |
b1bd055d MP |
131 | } |
132 | EXPORT_SYMBOL(blk_set_stacking_limits); | |
133 | ||
86db1e29 JA |
134 | /** |
135 | * blk_queue_make_request - define an alternate make_request function for a device | |
136 | * @q: the request queue for the device to be affected | |
137 | * @mfn: the alternate make_request function | |
138 | * | |
139 | * Description: | |
140 | * The normal way for &struct bios to be passed to a device | |
141 | * driver is for them to be collected into requests on a request | |
142 | * queue, and then to allow the device driver to select requests | |
143 | * off that queue when it is ready. This works well for many block | |
144 | * devices. However some block devices (typically virtual devices | |
145 | * such as md or lvm) do not benefit from the processing on the | |
146 | * request queue, and are served best by having the requests passed | |
147 | * directly to them. This can be achieved by providing a function | |
148 | * to blk_queue_make_request(). | |
149 | * | |
150 | * Caveat: | |
151 | * The driver that does this *must* be able to deal appropriately | |
152 | * with buffers in "highmemory". This can be accomplished by either calling | |
153 | * __bio_kmap_atomic() to get a temporary kernel mapping, or by calling | |
154 | * blk_queue_bounce() to create a buffer in normal memory. | |
155 | **/ | |
6728cb0e | 156 | void blk_queue_make_request(struct request_queue *q, make_request_fn *mfn) |
86db1e29 JA |
157 | { |
158 | /* | |
159 | * set defaults | |
160 | */ | |
161 | q->nr_requests = BLKDEV_MAX_RQ; | |
0e435ac2 | 162 | |
86db1e29 | 163 | q->make_request_fn = mfn; |
86db1e29 JA |
164 | blk_queue_dma_alignment(q, 511); |
165 | blk_queue_congestion_threshold(q); | |
166 | q->nr_batching = BLK_BATCH_REQ; | |
167 | ||
e475bba2 MP |
168 | blk_set_default_limits(&q->limits); |
169 | ||
86db1e29 JA |
170 | /* |
171 | * by default assume old behaviour and bounce for any highmem page | |
172 | */ | |
173 | blk_queue_bounce_limit(q, BLK_BOUNCE_HIGH); | |
174 | } | |
86db1e29 JA |
175 | EXPORT_SYMBOL(blk_queue_make_request); |
176 | ||
177 | /** | |
178 | * blk_queue_bounce_limit - set bounce buffer limit for queue | |
cd0aca2d | 179 | * @q: the request queue for the device |
9f7e45d8 | 180 | * @max_addr: the maximum address the device can handle |
86db1e29 JA |
181 | * |
182 | * Description: | |
183 | * Different hardware can have different requirements as to what pages | |
184 | * it can do I/O directly to. A low level driver can call | |
185 | * blk_queue_bounce_limit to have lower memory pages allocated as bounce | |
9f7e45d8 | 186 | * buffers for doing I/O to pages residing above @max_addr. |
86db1e29 | 187 | **/ |
9f7e45d8 | 188 | void blk_queue_bounce_limit(struct request_queue *q, u64 max_addr) |
86db1e29 | 189 | { |
9f7e45d8 | 190 | unsigned long b_pfn = max_addr >> PAGE_SHIFT; |
86db1e29 JA |
191 | int dma = 0; |
192 | ||
193 | q->bounce_gfp = GFP_NOIO; | |
194 | #if BITS_PER_LONG == 64 | |
cd0aca2d TH |
195 | /* |
196 | * Assume anything <= 4GB can be handled by IOMMU. Actually | |
197 | * some IOMMUs can handle everything, but I don't know of a | |
198 | * way to test this here. | |
199 | */ | |
200 | if (b_pfn < (min_t(u64, 0xffffffffUL, BLK_BOUNCE_HIGH) >> PAGE_SHIFT)) | |
86db1e29 | 201 | dma = 1; |
efb012b3 | 202 | q->limits.bounce_pfn = max(max_low_pfn, b_pfn); |
86db1e29 | 203 | #else |
6728cb0e | 204 | if (b_pfn < blk_max_low_pfn) |
86db1e29 | 205 | dma = 1; |
c49825fa | 206 | q->limits.bounce_pfn = b_pfn; |
260a67a9 | 207 | #endif |
86db1e29 JA |
208 | if (dma) { |
209 | init_emergency_isa_pool(); | |
210 | q->bounce_gfp = GFP_NOIO | GFP_DMA; | |
260a67a9 | 211 | q->limits.bounce_pfn = b_pfn; |
86db1e29 JA |
212 | } |
213 | } | |
86db1e29 JA |
214 | EXPORT_SYMBOL(blk_queue_bounce_limit); |
215 | ||
216 | /** | |
72d4cd9f MS |
217 | * blk_limits_max_hw_sectors - set hard and soft limit of max sectors for request |
218 | * @limits: the queue limits | |
2800aac1 | 219 | * @max_hw_sectors: max hardware sectors in the usual 512b unit |
86db1e29 JA |
220 | * |
221 | * Description: | |
2800aac1 MP |
222 | * Enables a low level driver to set a hard upper limit, |
223 | * max_hw_sectors, on the size of requests. max_hw_sectors is set by | |
4f258a46 MP |
224 | * the device driver based upon the capabilities of the I/O |
225 | * controller. | |
2800aac1 MP |
226 | * |
227 | * max_sectors is a soft limit imposed by the block layer for | |
228 | * filesystem type requests. This value can be overridden on a | |
229 | * per-device basis in /sys/block/<device>/queue/max_sectors_kb. | |
230 | * The soft limit can not exceed max_hw_sectors. | |
86db1e29 | 231 | **/ |
72d4cd9f | 232 | void blk_limits_max_hw_sectors(struct queue_limits *limits, unsigned int max_hw_sectors) |
86db1e29 | 233 | { |
2800aac1 MP |
234 | if ((max_hw_sectors << 9) < PAGE_CACHE_SIZE) { |
235 | max_hw_sectors = 1 << (PAGE_CACHE_SHIFT - 9); | |
24c03d47 | 236 | printk(KERN_INFO "%s: set to minimum %d\n", |
2800aac1 | 237 | __func__, max_hw_sectors); |
86db1e29 JA |
238 | } |
239 | ||
30e2bc08 JM |
240 | limits->max_hw_sectors = max_hw_sectors; |
241 | limits->max_sectors = min_t(unsigned int, max_hw_sectors, | |
242 | BLK_DEF_MAX_SECTORS); | |
72d4cd9f MS |
243 | } |
244 | EXPORT_SYMBOL(blk_limits_max_hw_sectors); | |
245 | ||
246 | /** | |
247 | * blk_queue_max_hw_sectors - set max sectors for a request for this queue | |
248 | * @q: the request queue for the device | |
249 | * @max_hw_sectors: max hardware sectors in the usual 512b unit | |
250 | * | |
251 | * Description: | |
252 | * See description for blk_limits_max_hw_sectors(). | |
253 | **/ | |
254 | void blk_queue_max_hw_sectors(struct request_queue *q, unsigned int max_hw_sectors) | |
255 | { | |
256 | blk_limits_max_hw_sectors(&q->limits, max_hw_sectors); | |
86db1e29 | 257 | } |
086fa5ff | 258 | EXPORT_SYMBOL(blk_queue_max_hw_sectors); |
86db1e29 | 259 | |
762380ad JA |
260 | /** |
261 | * blk_queue_chunk_sectors - set size of the chunk for this queue | |
262 | * @q: the request queue for the device | |
263 | * @chunk_sectors: chunk sectors in the usual 512b unit | |
264 | * | |
265 | * Description: | |
266 | * If a driver doesn't want IOs to cross a given chunk size, it can set | |
267 | * this limit and prevent merging across chunks. Note that the chunk size | |
58a4915a JA |
268 | * must currently be a power-of-2 in sectors. Also note that the block |
269 | * layer must accept a page worth of data at any offset. So if the | |
270 | * crossing of chunks is a hard limitation in the driver, it must still be | |
271 | * prepared to split single page bios. | |
762380ad JA |
272 | **/ |
273 | void blk_queue_chunk_sectors(struct request_queue *q, unsigned int chunk_sectors) | |
274 | { | |
275 | BUG_ON(!is_power_of_2(chunk_sectors)); | |
276 | q->limits.chunk_sectors = chunk_sectors; | |
277 | } | |
278 | EXPORT_SYMBOL(blk_queue_chunk_sectors); | |
279 | ||
67efc925 CH |
280 | /** |
281 | * blk_queue_max_discard_sectors - set max sectors for a single discard | |
282 | * @q: the request queue for the device | |
c7ebf065 | 283 | * @max_discard_sectors: maximum number of sectors to discard |
67efc925 CH |
284 | **/ |
285 | void blk_queue_max_discard_sectors(struct request_queue *q, | |
286 | unsigned int max_discard_sectors) | |
287 | { | |
0034af03 | 288 | q->limits.max_hw_discard_sectors = max_discard_sectors; |
67efc925 CH |
289 | q->limits.max_discard_sectors = max_discard_sectors; |
290 | } | |
291 | EXPORT_SYMBOL(blk_queue_max_discard_sectors); | |
292 | ||
4363ac7c MP |
293 | /** |
294 | * blk_queue_max_write_same_sectors - set max sectors for a single write same | |
295 | * @q: the request queue for the device | |
296 | * @max_write_same_sectors: maximum number of sectors to write per command | |
297 | **/ | |
298 | void blk_queue_max_write_same_sectors(struct request_queue *q, | |
299 | unsigned int max_write_same_sectors) | |
300 | { | |
301 | q->limits.max_write_same_sectors = max_write_same_sectors; | |
302 | } | |
303 | EXPORT_SYMBOL(blk_queue_max_write_same_sectors); | |
304 | ||
86db1e29 | 305 | /** |
8a78362c | 306 | * blk_queue_max_segments - set max hw segments for a request for this queue |
86db1e29 JA |
307 | * @q: the request queue for the device |
308 | * @max_segments: max number of segments | |
309 | * | |
310 | * Description: | |
311 | * Enables a low level driver to set an upper limit on the number of | |
8a78362c | 312 | * hw data segments in a request. |
86db1e29 | 313 | **/ |
8a78362c | 314 | void blk_queue_max_segments(struct request_queue *q, unsigned short max_segments) |
86db1e29 JA |
315 | { |
316 | if (!max_segments) { | |
317 | max_segments = 1; | |
24c03d47 HH |
318 | printk(KERN_INFO "%s: set to minimum %d\n", |
319 | __func__, max_segments); | |
86db1e29 JA |
320 | } |
321 | ||
8a78362c | 322 | q->limits.max_segments = max_segments; |
86db1e29 | 323 | } |
8a78362c | 324 | EXPORT_SYMBOL(blk_queue_max_segments); |
86db1e29 JA |
325 | |
326 | /** | |
327 | * blk_queue_max_segment_size - set max segment size for blk_rq_map_sg | |
328 | * @q: the request queue for the device | |
329 | * @max_size: max size of segment in bytes | |
330 | * | |
331 | * Description: | |
332 | * Enables a low level driver to set an upper limit on the size of a | |
333 | * coalesced segment | |
334 | **/ | |
335 | void blk_queue_max_segment_size(struct request_queue *q, unsigned int max_size) | |
336 | { | |
337 | if (max_size < PAGE_CACHE_SIZE) { | |
338 | max_size = PAGE_CACHE_SIZE; | |
24c03d47 HH |
339 | printk(KERN_INFO "%s: set to minimum %d\n", |
340 | __func__, max_size); | |
86db1e29 JA |
341 | } |
342 | ||
025146e1 | 343 | q->limits.max_segment_size = max_size; |
86db1e29 | 344 | } |
86db1e29 JA |
345 | EXPORT_SYMBOL(blk_queue_max_segment_size); |
346 | ||
347 | /** | |
e1defc4f | 348 | * blk_queue_logical_block_size - set logical block size for the queue |
86db1e29 | 349 | * @q: the request queue for the device |
e1defc4f | 350 | * @size: the logical block size, in bytes |
86db1e29 JA |
351 | * |
352 | * Description: | |
e1defc4f MP |
353 | * This should be set to the lowest possible block size that the |
354 | * storage device can address. The default of 512 covers most | |
355 | * hardware. | |
86db1e29 | 356 | **/ |
e1defc4f | 357 | void blk_queue_logical_block_size(struct request_queue *q, unsigned short size) |
86db1e29 | 358 | { |
025146e1 | 359 | q->limits.logical_block_size = size; |
c72758f3 MP |
360 | |
361 | if (q->limits.physical_block_size < size) | |
362 | q->limits.physical_block_size = size; | |
363 | ||
364 | if (q->limits.io_min < q->limits.physical_block_size) | |
365 | q->limits.io_min = q->limits.physical_block_size; | |
86db1e29 | 366 | } |
e1defc4f | 367 | EXPORT_SYMBOL(blk_queue_logical_block_size); |
86db1e29 | 368 | |
c72758f3 MP |
369 | /** |
370 | * blk_queue_physical_block_size - set physical block size for the queue | |
371 | * @q: the request queue for the device | |
372 | * @size: the physical block size, in bytes | |
373 | * | |
374 | * Description: | |
375 | * This should be set to the lowest possible sector size that the | |
376 | * hardware can operate on without reverting to read-modify-write | |
377 | * operations. | |
378 | */ | |
892b6f90 | 379 | void blk_queue_physical_block_size(struct request_queue *q, unsigned int size) |
c72758f3 MP |
380 | { |
381 | q->limits.physical_block_size = size; | |
382 | ||
383 | if (q->limits.physical_block_size < q->limits.logical_block_size) | |
384 | q->limits.physical_block_size = q->limits.logical_block_size; | |
385 | ||
386 | if (q->limits.io_min < q->limits.physical_block_size) | |
387 | q->limits.io_min = q->limits.physical_block_size; | |
388 | } | |
389 | EXPORT_SYMBOL(blk_queue_physical_block_size); | |
390 | ||
391 | /** | |
392 | * blk_queue_alignment_offset - set physical block alignment offset | |
393 | * @q: the request queue for the device | |
8ebf9756 | 394 | * @offset: alignment offset in bytes |
c72758f3 MP |
395 | * |
396 | * Description: | |
397 | * Some devices are naturally misaligned to compensate for things like | |
398 | * the legacy DOS partition table 63-sector offset. Low-level drivers | |
399 | * should call this function for devices whose first sector is not | |
400 | * naturally aligned. | |
401 | */ | |
402 | void blk_queue_alignment_offset(struct request_queue *q, unsigned int offset) | |
403 | { | |
404 | q->limits.alignment_offset = | |
405 | offset & (q->limits.physical_block_size - 1); | |
406 | q->limits.misaligned = 0; | |
407 | } | |
408 | EXPORT_SYMBOL(blk_queue_alignment_offset); | |
409 | ||
7c958e32 MP |
410 | /** |
411 | * blk_limits_io_min - set minimum request size for a device | |
412 | * @limits: the queue limits | |
413 | * @min: smallest I/O size in bytes | |
414 | * | |
415 | * Description: | |
416 | * Some devices have an internal block size bigger than the reported | |
417 | * hardware sector size. This function can be used to signal the | |
418 | * smallest I/O the device can perform without incurring a performance | |
419 | * penalty. | |
420 | */ | |
421 | void blk_limits_io_min(struct queue_limits *limits, unsigned int min) | |
422 | { | |
423 | limits->io_min = min; | |
424 | ||
425 | if (limits->io_min < limits->logical_block_size) | |
426 | limits->io_min = limits->logical_block_size; | |
427 | ||
428 | if (limits->io_min < limits->physical_block_size) | |
429 | limits->io_min = limits->physical_block_size; | |
430 | } | |
431 | EXPORT_SYMBOL(blk_limits_io_min); | |
432 | ||
c72758f3 MP |
433 | /** |
434 | * blk_queue_io_min - set minimum request size for the queue | |
435 | * @q: the request queue for the device | |
8ebf9756 | 436 | * @min: smallest I/O size in bytes |
c72758f3 MP |
437 | * |
438 | * Description: | |
7e5f5fb0 MP |
439 | * Storage devices may report a granularity or preferred minimum I/O |
440 | * size which is the smallest request the device can perform without | |
441 | * incurring a performance penalty. For disk drives this is often the | |
442 | * physical block size. For RAID arrays it is often the stripe chunk | |
443 | * size. A properly aligned multiple of minimum_io_size is the | |
444 | * preferred request size for workloads where a high number of I/O | |
445 | * operations is desired. | |
c72758f3 MP |
446 | */ |
447 | void blk_queue_io_min(struct request_queue *q, unsigned int min) | |
448 | { | |
7c958e32 | 449 | blk_limits_io_min(&q->limits, min); |
c72758f3 MP |
450 | } |
451 | EXPORT_SYMBOL(blk_queue_io_min); | |
452 | ||
3c5820c7 MP |
453 | /** |
454 | * blk_limits_io_opt - set optimal request size for a device | |
455 | * @limits: the queue limits | |
456 | * @opt: smallest I/O size in bytes | |
457 | * | |
458 | * Description: | |
459 | * Storage devices may report an optimal I/O size, which is the | |
460 | * device's preferred unit for sustained I/O. This is rarely reported | |
461 | * for disk drives. For RAID arrays it is usually the stripe width or | |
462 | * the internal track size. A properly aligned multiple of | |
463 | * optimal_io_size is the preferred request size for workloads where | |
464 | * sustained throughput is desired. | |
465 | */ | |
466 | void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt) | |
467 | { | |
468 | limits->io_opt = opt; | |
469 | } | |
470 | EXPORT_SYMBOL(blk_limits_io_opt); | |
471 | ||
c72758f3 MP |
472 | /** |
473 | * blk_queue_io_opt - set optimal request size for the queue | |
474 | * @q: the request queue for the device | |
8ebf9756 | 475 | * @opt: optimal request size in bytes |
c72758f3 MP |
476 | * |
477 | * Description: | |
7e5f5fb0 MP |
478 | * Storage devices may report an optimal I/O size, which is the |
479 | * device's preferred unit for sustained I/O. This is rarely reported | |
480 | * for disk drives. For RAID arrays it is usually the stripe width or | |
481 | * the internal track size. A properly aligned multiple of | |
482 | * optimal_io_size is the preferred request size for workloads where | |
483 | * sustained throughput is desired. | |
c72758f3 MP |
484 | */ |
485 | void blk_queue_io_opt(struct request_queue *q, unsigned int opt) | |
486 | { | |
3c5820c7 | 487 | blk_limits_io_opt(&q->limits, opt); |
c72758f3 MP |
488 | } |
489 | EXPORT_SYMBOL(blk_queue_io_opt); | |
490 | ||
86db1e29 JA |
491 | /** |
492 | * blk_queue_stack_limits - inherit underlying queue limits for stacked drivers | |
493 | * @t: the stacking driver (top) | |
494 | * @b: the underlying device (bottom) | |
495 | **/ | |
496 | void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b) | |
497 | { | |
fef24667 | 498 | blk_stack_limits(&t->limits, &b->limits, 0); |
86db1e29 | 499 | } |
86db1e29 JA |
500 | EXPORT_SYMBOL(blk_queue_stack_limits); |
501 | ||
c72758f3 MP |
502 | /** |
503 | * blk_stack_limits - adjust queue_limits for stacked devices | |
81744ee4 MP |
504 | * @t: the stacking driver limits (top device) |
505 | * @b: the underlying queue limits (bottom, component device) | |
e03a72e1 | 506 | * @start: first data sector within component device |
c72758f3 MP |
507 | * |
508 | * Description: | |
81744ee4 MP |
509 | * This function is used by stacking drivers like MD and DM to ensure |
510 | * that all component devices have compatible block sizes and | |
511 | * alignments. The stacking driver must provide a queue_limits | |
512 | * struct (top) and then iteratively call the stacking function for | |
513 | * all component (bottom) devices. The stacking function will | |
514 | * attempt to combine the values and ensure proper alignment. | |
515 | * | |
516 | * Returns 0 if the top and bottom queue_limits are compatible. The | |
517 | * top device's block sizes and alignment offsets may be adjusted to | |
518 | * ensure alignment with the bottom device. If no compatible sizes | |
519 | * and alignments exist, -1 is returned and the resulting top | |
520 | * queue_limits will have the misaligned flag set to indicate that | |
521 | * the alignment_offset is undefined. | |
c72758f3 MP |
522 | */ |
523 | int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, | |
e03a72e1 | 524 | sector_t start) |
c72758f3 | 525 | { |
e03a72e1 | 526 | unsigned int top, bottom, alignment, ret = 0; |
86b37281 | 527 | |
c72758f3 MP |
528 | t->max_sectors = min_not_zero(t->max_sectors, b->max_sectors); |
529 | t->max_hw_sectors = min_not_zero(t->max_hw_sectors, b->max_hw_sectors); | |
4363ac7c MP |
530 | t->max_write_same_sectors = min(t->max_write_same_sectors, |
531 | b->max_write_same_sectors); | |
77634f33 | 532 | t->bounce_pfn = min_not_zero(t->bounce_pfn, b->bounce_pfn); |
c72758f3 MP |
533 | |
534 | t->seg_boundary_mask = min_not_zero(t->seg_boundary_mask, | |
535 | b->seg_boundary_mask); | |
03100aad KB |
536 | t->virt_boundary_mask = min_not_zero(t->virt_boundary_mask, |
537 | b->virt_boundary_mask); | |
c72758f3 | 538 | |
8a78362c | 539 | t->max_segments = min_not_zero(t->max_segments, b->max_segments); |
13f05c8d MP |
540 | t->max_integrity_segments = min_not_zero(t->max_integrity_segments, |
541 | b->max_integrity_segments); | |
c72758f3 MP |
542 | |
543 | t->max_segment_size = min_not_zero(t->max_segment_size, | |
544 | b->max_segment_size); | |
545 | ||
fe0b393f MP |
546 | t->misaligned |= b->misaligned; |
547 | ||
e03a72e1 | 548 | alignment = queue_limit_alignment_offset(b, start); |
9504e086 | 549 | |
81744ee4 MP |
550 | /* Bottom device has different alignment. Check that it is |
551 | * compatible with the current top alignment. | |
552 | */ | |
9504e086 MP |
553 | if (t->alignment_offset != alignment) { |
554 | ||
555 | top = max(t->physical_block_size, t->io_min) | |
556 | + t->alignment_offset; | |
81744ee4 | 557 | bottom = max(b->physical_block_size, b->io_min) + alignment; |
9504e086 | 558 | |
81744ee4 | 559 | /* Verify that top and bottom intervals line up */ |
b8839b8c | 560 | if (max(top, bottom) % min(top, bottom)) { |
9504e086 | 561 | t->misaligned = 1; |
fe0b393f MP |
562 | ret = -1; |
563 | } | |
9504e086 MP |
564 | } |
565 | ||
c72758f3 MP |
566 | t->logical_block_size = max(t->logical_block_size, |
567 | b->logical_block_size); | |
568 | ||
569 | t->physical_block_size = max(t->physical_block_size, | |
570 | b->physical_block_size); | |
571 | ||
572 | t->io_min = max(t->io_min, b->io_min); | |
e9637415 | 573 | t->io_opt = lcm_not_zero(t->io_opt, b->io_opt); |
9504e086 | 574 | |
e692cb66 | 575 | t->cluster &= b->cluster; |
98262f27 | 576 | t->discard_zeroes_data &= b->discard_zeroes_data; |
c72758f3 | 577 | |
81744ee4 | 578 | /* Physical block size a multiple of the logical block size? */ |
9504e086 MP |
579 | if (t->physical_block_size & (t->logical_block_size - 1)) { |
580 | t->physical_block_size = t->logical_block_size; | |
c72758f3 | 581 | t->misaligned = 1; |
fe0b393f | 582 | ret = -1; |
86b37281 MP |
583 | } |
584 | ||
81744ee4 | 585 | /* Minimum I/O a multiple of the physical block size? */ |
9504e086 MP |
586 | if (t->io_min & (t->physical_block_size - 1)) { |
587 | t->io_min = t->physical_block_size; | |
588 | t->misaligned = 1; | |
fe0b393f | 589 | ret = -1; |
c72758f3 MP |
590 | } |
591 | ||
81744ee4 | 592 | /* Optimal I/O a multiple of the physical block size? */ |
9504e086 MP |
593 | if (t->io_opt & (t->physical_block_size - 1)) { |
594 | t->io_opt = 0; | |
595 | t->misaligned = 1; | |
fe0b393f | 596 | ret = -1; |
9504e086 | 597 | } |
c72758f3 | 598 | |
c78afc62 KO |
599 | t->raid_partial_stripes_expensive = |
600 | max(t->raid_partial_stripes_expensive, | |
601 | b->raid_partial_stripes_expensive); | |
602 | ||
81744ee4 | 603 | /* Find lowest common alignment_offset */ |
e9637415 | 604 | t->alignment_offset = lcm_not_zero(t->alignment_offset, alignment) |
b8839b8c | 605 | % max(t->physical_block_size, t->io_min); |
86b37281 | 606 | |
81744ee4 | 607 | /* Verify that new alignment_offset is on a logical block boundary */ |
fe0b393f | 608 | if (t->alignment_offset & (t->logical_block_size - 1)) { |
c72758f3 | 609 | t->misaligned = 1; |
fe0b393f MP |
610 | ret = -1; |
611 | } | |
c72758f3 | 612 | |
9504e086 MP |
613 | /* Discard alignment and granularity */ |
614 | if (b->discard_granularity) { | |
e03a72e1 | 615 | alignment = queue_limit_discard_alignment(b, start); |
9504e086 MP |
616 | |
617 | if (t->discard_granularity != 0 && | |
618 | t->discard_alignment != alignment) { | |
619 | top = t->discard_granularity + t->discard_alignment; | |
620 | bottom = b->discard_granularity + alignment; | |
70dd5bf3 | 621 | |
9504e086 | 622 | /* Verify that top and bottom intervals line up */ |
8dd2cb7e | 623 | if ((max(top, bottom) % min(top, bottom)) != 0) |
9504e086 MP |
624 | t->discard_misaligned = 1; |
625 | } | |
626 | ||
81744ee4 MP |
627 | t->max_discard_sectors = min_not_zero(t->max_discard_sectors, |
628 | b->max_discard_sectors); | |
0034af03 JA |
629 | t->max_hw_discard_sectors = min_not_zero(t->max_hw_discard_sectors, |
630 | b->max_hw_discard_sectors); | |
9504e086 MP |
631 | t->discard_granularity = max(t->discard_granularity, |
632 | b->discard_granularity); | |
e9637415 | 633 | t->discard_alignment = lcm_not_zero(t->discard_alignment, alignment) % |
8dd2cb7e | 634 | t->discard_granularity; |
9504e086 | 635 | } |
70dd5bf3 | 636 | |
fe0b393f | 637 | return ret; |
c72758f3 | 638 | } |
5d85d324 | 639 | EXPORT_SYMBOL(blk_stack_limits); |
c72758f3 | 640 | |
17be8c24 MP |
641 | /** |
642 | * bdev_stack_limits - adjust queue limits for stacked drivers | |
643 | * @t: the stacking driver limits (top device) | |
644 | * @bdev: the component block_device (bottom) | |
645 | * @start: first data sector within component device | |
646 | * | |
647 | * Description: | |
648 | * Merges queue limits for a top device and a block_device. Returns | |
649 | * 0 if alignment didn't change. Returns -1 if adding the bottom | |
650 | * device caused misalignment. | |
651 | */ | |
652 | int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev, | |
653 | sector_t start) | |
654 | { | |
655 | struct request_queue *bq = bdev_get_queue(bdev); | |
656 | ||
657 | start += get_start_sect(bdev); | |
658 | ||
e03a72e1 | 659 | return blk_stack_limits(t, &bq->limits, start); |
17be8c24 MP |
660 | } |
661 | EXPORT_SYMBOL(bdev_stack_limits); | |
662 | ||
c72758f3 MP |
663 | /** |
664 | * disk_stack_limits - adjust queue limits for stacked drivers | |
77634f33 | 665 | * @disk: MD/DM gendisk (top) |
c72758f3 MP |
666 | * @bdev: the underlying block device (bottom) |
667 | * @offset: offset to beginning of data within component device | |
668 | * | |
669 | * Description: | |
e03a72e1 MP |
670 | * Merges the limits for a top level gendisk and a bottom level |
671 | * block_device. | |
c72758f3 MP |
672 | */ |
673 | void disk_stack_limits(struct gendisk *disk, struct block_device *bdev, | |
674 | sector_t offset) | |
675 | { | |
676 | struct request_queue *t = disk->queue; | |
c72758f3 | 677 | |
e03a72e1 | 678 | if (bdev_stack_limits(&t->limits, bdev, offset >> 9) < 0) { |
c72758f3 MP |
679 | char top[BDEVNAME_SIZE], bottom[BDEVNAME_SIZE]; |
680 | ||
681 | disk_name(disk, 0, top); | |
682 | bdevname(bdev, bottom); | |
683 | ||
684 | printk(KERN_NOTICE "%s: Warning: Device %s is misaligned\n", | |
685 | top, bottom); | |
686 | } | |
c72758f3 MP |
687 | } |
688 | EXPORT_SYMBOL(disk_stack_limits); | |
689 | ||
e3790c7d TH |
690 | /** |
691 | * blk_queue_dma_pad - set pad mask | |
692 | * @q: the request queue for the device | |
693 | * @mask: pad mask | |
694 | * | |
27f8221a | 695 | * Set dma pad mask. |
e3790c7d | 696 | * |
27f8221a FT |
697 | * Appending pad buffer to a request modifies the last entry of a |
698 | * scatter list such that it includes the pad buffer. | |
e3790c7d TH |
699 | **/ |
700 | void blk_queue_dma_pad(struct request_queue *q, unsigned int mask) | |
701 | { | |
702 | q->dma_pad_mask = mask; | |
703 | } | |
704 | EXPORT_SYMBOL(blk_queue_dma_pad); | |
705 | ||
27f8221a FT |
706 | /** |
707 | * blk_queue_update_dma_pad - update pad mask | |
708 | * @q: the request queue for the device | |
709 | * @mask: pad mask | |
710 | * | |
711 | * Update dma pad mask. | |
712 | * | |
713 | * Appending pad buffer to a request modifies the last entry of a | |
714 | * scatter list such that it includes the pad buffer. | |
715 | **/ | |
716 | void blk_queue_update_dma_pad(struct request_queue *q, unsigned int mask) | |
717 | { | |
718 | if (mask > q->dma_pad_mask) | |
719 | q->dma_pad_mask = mask; | |
720 | } | |
721 | EXPORT_SYMBOL(blk_queue_update_dma_pad); | |
722 | ||
86db1e29 JA |
723 | /** |
724 | * blk_queue_dma_drain - Set up a drain buffer for excess dma. | |
86db1e29 | 725 | * @q: the request queue for the device |
2fb98e84 | 726 | * @dma_drain_needed: fn which returns non-zero if drain is necessary |
86db1e29 JA |
727 | * @buf: physically contiguous buffer |
728 | * @size: size of the buffer in bytes | |
729 | * | |
730 | * Some devices have excess DMA problems and can't simply discard (or | |
731 | * zero fill) the unwanted piece of the transfer. They have to have a | |
732 | * real area of memory to transfer it into. The use case for this is | |
733 | * ATAPI devices in DMA mode. If the packet command causes a transfer | |
734 | * bigger than the transfer size some HBAs will lock up if there | |
735 | * aren't DMA elements to contain the excess transfer. What this API | |
736 | * does is adjust the queue so that the buf is always appended | |
737 | * silently to the scatterlist. | |
738 | * | |
8a78362c MP |
739 | * Note: This routine adjusts max_hw_segments to make room for appending |
740 | * the drain buffer. If you call blk_queue_max_segments() after calling | |
741 | * this routine, you must set the limit to one fewer than your device | |
742 | * can support otherwise there won't be room for the drain buffer. | |
86db1e29 | 743 | */ |
448da4d2 | 744 | int blk_queue_dma_drain(struct request_queue *q, |
2fb98e84 TH |
745 | dma_drain_needed_fn *dma_drain_needed, |
746 | void *buf, unsigned int size) | |
86db1e29 | 747 | { |
8a78362c | 748 | if (queue_max_segments(q) < 2) |
86db1e29 JA |
749 | return -EINVAL; |
750 | /* make room for appending the drain */ | |
8a78362c | 751 | blk_queue_max_segments(q, queue_max_segments(q) - 1); |
2fb98e84 | 752 | q->dma_drain_needed = dma_drain_needed; |
86db1e29 JA |
753 | q->dma_drain_buffer = buf; |
754 | q->dma_drain_size = size; | |
755 | ||
756 | return 0; | |
757 | } | |
86db1e29 JA |
758 | EXPORT_SYMBOL_GPL(blk_queue_dma_drain); |
759 | ||
760 | /** | |
761 | * blk_queue_segment_boundary - set boundary rules for segment merging | |
762 | * @q: the request queue for the device | |
763 | * @mask: the memory boundary mask | |
764 | **/ | |
765 | void blk_queue_segment_boundary(struct request_queue *q, unsigned long mask) | |
766 | { | |
767 | if (mask < PAGE_CACHE_SIZE - 1) { | |
768 | mask = PAGE_CACHE_SIZE - 1; | |
24c03d47 HH |
769 | printk(KERN_INFO "%s: set to minimum %lx\n", |
770 | __func__, mask); | |
86db1e29 JA |
771 | } |
772 | ||
025146e1 | 773 | q->limits.seg_boundary_mask = mask; |
86db1e29 | 774 | } |
86db1e29 JA |
775 | EXPORT_SYMBOL(blk_queue_segment_boundary); |
776 | ||
03100aad KB |
777 | /** |
778 | * blk_queue_virt_boundary - set boundary rules for bio merging | |
779 | * @q: the request queue for the device | |
780 | * @mask: the memory boundary mask | |
781 | **/ | |
782 | void blk_queue_virt_boundary(struct request_queue *q, unsigned long mask) | |
783 | { | |
784 | q->limits.virt_boundary_mask = mask; | |
785 | } | |
786 | EXPORT_SYMBOL(blk_queue_virt_boundary); | |
787 | ||
86db1e29 JA |
788 | /** |
789 | * blk_queue_dma_alignment - set dma length and memory alignment | |
790 | * @q: the request queue for the device | |
791 | * @mask: alignment mask | |
792 | * | |
793 | * description: | |
710027a4 | 794 | * set required memory and length alignment for direct dma transactions. |
8feb4d20 | 795 | * this is used when building direct io requests for the queue. |
86db1e29 JA |
796 | * |
797 | **/ | |
798 | void blk_queue_dma_alignment(struct request_queue *q, int mask) | |
799 | { | |
800 | q->dma_alignment = mask; | |
801 | } | |
86db1e29 JA |
802 | EXPORT_SYMBOL(blk_queue_dma_alignment); |
803 | ||
804 | /** | |
805 | * blk_queue_update_dma_alignment - update dma length and memory alignment | |
806 | * @q: the request queue for the device | |
807 | * @mask: alignment mask | |
808 | * | |
809 | * description: | |
710027a4 | 810 | * update required memory and length alignment for direct dma transactions. |
86db1e29 JA |
811 | * If the requested alignment is larger than the current alignment, then |
812 | * the current queue alignment is updated to the new value, otherwise it | |
813 | * is left alone. The design of this is to allow multiple objects | |
814 | * (driver, device, transport etc) to set their respective | |
815 | * alignments without having them interfere. | |
816 | * | |
817 | **/ | |
818 | void blk_queue_update_dma_alignment(struct request_queue *q, int mask) | |
819 | { | |
820 | BUG_ON(mask > PAGE_SIZE); | |
821 | ||
822 | if (mask > q->dma_alignment) | |
823 | q->dma_alignment = mask; | |
824 | } | |
86db1e29 JA |
825 | EXPORT_SYMBOL(blk_queue_update_dma_alignment); |
826 | ||
4913efe4 TH |
827 | /** |
828 | * blk_queue_flush - configure queue's cache flush capability | |
829 | * @q: the request queue for the device | |
830 | * @flush: 0, REQ_FLUSH or REQ_FLUSH | REQ_FUA | |
831 | * | |
832 | * Tell block layer cache flush capability of @q. If it supports | |
833 | * flushing, REQ_FLUSH should be set. If it supports bypassing | |
834 | * write cache for individual writes, REQ_FUA should be set. | |
835 | */ | |
836 | void blk_queue_flush(struct request_queue *q, unsigned int flush) | |
837 | { | |
838 | WARN_ON_ONCE(flush & ~(REQ_FLUSH | REQ_FUA)); | |
839 | ||
840 | if (WARN_ON_ONCE(!(flush & REQ_FLUSH) && (flush & REQ_FUA))) | |
841 | flush &= ~REQ_FUA; | |
842 | ||
843 | q->flush_flags = flush & (REQ_FLUSH | REQ_FUA); | |
844 | } | |
845 | EXPORT_SYMBOL_GPL(blk_queue_flush); | |
846 | ||
f3876930 | 847 | void blk_queue_flush_queueable(struct request_queue *q, bool queueable) |
848 | { | |
849 | q->flush_not_queueable = !queueable; | |
850 | } | |
851 | EXPORT_SYMBOL_GPL(blk_queue_flush_queueable); | |
852 | ||
aeb3d3a8 | 853 | static int __init blk_settings_init(void) |
86db1e29 JA |
854 | { |
855 | blk_max_low_pfn = max_low_pfn - 1; | |
856 | blk_max_pfn = max_pfn - 1; | |
857 | return 0; | |
858 | } | |
859 | subsys_initcall(blk_settings_init); |