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