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> | |
57c8a661 | 9 | #include <linux/memblock.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" | |
87760e5e | 16 | #include "blk-wbt.h" |
86db1e29 | 17 | |
6728cb0e | 18 | unsigned long blk_max_low_pfn; |
86db1e29 | 19 | EXPORT_SYMBOL(blk_max_low_pfn); |
6728cb0e JA |
20 | |
21 | unsigned long blk_max_pfn; | |
86db1e29 | 22 | |
242f9dcb JA |
23 | void blk_queue_rq_timeout(struct request_queue *q, unsigned int timeout) |
24 | { | |
25 | q->rq_timeout = timeout; | |
26 | } | |
27 | EXPORT_SYMBOL_GPL(blk_queue_rq_timeout); | |
28 | ||
e475bba2 MP |
29 | /** |
30 | * blk_set_default_limits - reset limits to default values | |
f740f5ca | 31 | * @lim: the queue_limits structure to reset |
e475bba2 MP |
32 | * |
33 | * Description: | |
b1bd055d | 34 | * Returns a queue_limit struct to its default state. |
e475bba2 MP |
35 | */ |
36 | void blk_set_default_limits(struct queue_limits *lim) | |
37 | { | |
8a78362c | 38 | lim->max_segments = BLK_MAX_SEGMENTS; |
1e739730 | 39 | lim->max_discard_segments = 1; |
13f05c8d | 40 | lim->max_integrity_segments = 0; |
e475bba2 | 41 | lim->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK; |
03100aad | 42 | lim->virt_boundary_mask = 0; |
eb28d31b | 43 | lim->max_segment_size = BLK_MAX_SEGMENT_SIZE; |
5f009d3f KB |
44 | lim->max_sectors = lim->max_hw_sectors = BLK_SAFE_MAX_SECTORS; |
45 | lim->max_dev_sectors = 0; | |
762380ad | 46 | lim->chunk_sectors = 0; |
4363ac7c | 47 | lim->max_write_same_sectors = 0; |
a6f0788e | 48 | lim->max_write_zeroes_sectors = 0; |
86b37281 | 49 | lim->max_discard_sectors = 0; |
0034af03 | 50 | lim->max_hw_discard_sectors = 0; |
86b37281 MP |
51 | lim->discard_granularity = 0; |
52 | lim->discard_alignment = 0; | |
53 | lim->discard_misaligned = 0; | |
e475bba2 | 54 | lim->logical_block_size = lim->physical_block_size = lim->io_min = 512; |
3a02c8e8 | 55 | lim->bounce_pfn = (unsigned long)(BLK_BOUNCE_ANY >> PAGE_SHIFT); |
e475bba2 MP |
56 | lim->alignment_offset = 0; |
57 | lim->io_opt = 0; | |
58 | lim->misaligned = 0; | |
797476b8 | 59 | lim->zoned = BLK_ZONED_NONE; |
e475bba2 MP |
60 | } |
61 | EXPORT_SYMBOL(blk_set_default_limits); | |
62 | ||
b1bd055d MP |
63 | /** |
64 | * blk_set_stacking_limits - set default limits for stacking devices | |
65 | * @lim: the queue_limits structure to reset | |
66 | * | |
67 | * Description: | |
68 | * Returns a queue_limit struct to its default state. Should be used | |
69 | * by stacking drivers like DM that have no internal limits. | |
70 | */ | |
71 | void blk_set_stacking_limits(struct queue_limits *lim) | |
72 | { | |
73 | blk_set_default_limits(lim); | |
74 | ||
75 | /* Inherit limits from component devices */ | |
b1bd055d | 76 | lim->max_segments = USHRT_MAX; |
42c9cdfe | 77 | lim->max_discard_segments = USHRT_MAX; |
b1bd055d | 78 | lim->max_hw_sectors = UINT_MAX; |
d82ae52e | 79 | lim->max_segment_size = UINT_MAX; |
fe86cdce | 80 | lim->max_sectors = UINT_MAX; |
ca369d51 | 81 | lim->max_dev_sectors = UINT_MAX; |
4363ac7c | 82 | lim->max_write_same_sectors = UINT_MAX; |
a6f0788e | 83 | lim->max_write_zeroes_sectors = UINT_MAX; |
b1bd055d MP |
84 | } |
85 | EXPORT_SYMBOL(blk_set_stacking_limits); | |
86 | ||
86db1e29 JA |
87 | /** |
88 | * blk_queue_make_request - define an alternate make_request function for a device | |
89 | * @q: the request queue for the device to be affected | |
90 | * @mfn: the alternate make_request function | |
91 | * | |
92 | * Description: | |
93 | * The normal way for &struct bios to be passed to a device | |
94 | * driver is for them to be collected into requests on a request | |
95 | * queue, and then to allow the device driver to select requests | |
96 | * off that queue when it is ready. This works well for many block | |
97 | * devices. However some block devices (typically virtual devices | |
98 | * such as md or lvm) do not benefit from the processing on the | |
99 | * request queue, and are served best by having the requests passed | |
100 | * directly to them. This can be achieved by providing a function | |
101 | * to blk_queue_make_request(). | |
102 | * | |
103 | * Caveat: | |
104 | * The driver that does this *must* be able to deal appropriately | |
105 | * with buffers in "highmemory". This can be accomplished by either calling | |
d004a5e7 | 106 | * kmap_atomic() to get a temporary kernel mapping, or by calling |
86db1e29 JA |
107 | * blk_queue_bounce() to create a buffer in normal memory. |
108 | **/ | |
6728cb0e | 109 | void blk_queue_make_request(struct request_queue *q, make_request_fn *mfn) |
86db1e29 JA |
110 | { |
111 | /* | |
112 | * set defaults | |
113 | */ | |
114 | q->nr_requests = BLKDEV_MAX_RQ; | |
0e435ac2 | 115 | |
86db1e29 | 116 | q->make_request_fn = mfn; |
86db1e29 | 117 | blk_queue_dma_alignment(q, 511); |
86db1e29 | 118 | |
e475bba2 | 119 | blk_set_default_limits(&q->limits); |
86db1e29 | 120 | } |
86db1e29 JA |
121 | EXPORT_SYMBOL(blk_queue_make_request); |
122 | ||
123 | /** | |
124 | * blk_queue_bounce_limit - set bounce buffer limit for queue | |
cd0aca2d | 125 | * @q: the request queue for the device |
9f7e45d8 | 126 | * @max_addr: the maximum address the device can handle |
86db1e29 JA |
127 | * |
128 | * Description: | |
129 | * Different hardware can have different requirements as to what pages | |
130 | * it can do I/O directly to. A low level driver can call | |
131 | * blk_queue_bounce_limit to have lower memory pages allocated as bounce | |
9f7e45d8 | 132 | * buffers for doing I/O to pages residing above @max_addr. |
86db1e29 | 133 | **/ |
9f7e45d8 | 134 | void blk_queue_bounce_limit(struct request_queue *q, u64 max_addr) |
86db1e29 | 135 | { |
9f7e45d8 | 136 | unsigned long b_pfn = max_addr >> PAGE_SHIFT; |
86db1e29 JA |
137 | int dma = 0; |
138 | ||
139 | q->bounce_gfp = GFP_NOIO; | |
140 | #if BITS_PER_LONG == 64 | |
cd0aca2d TH |
141 | /* |
142 | * Assume anything <= 4GB can be handled by IOMMU. Actually | |
143 | * some IOMMUs can handle everything, but I don't know of a | |
144 | * way to test this here. | |
145 | */ | |
146 | if (b_pfn < (min_t(u64, 0xffffffffUL, BLK_BOUNCE_HIGH) >> PAGE_SHIFT)) | |
86db1e29 | 147 | dma = 1; |
efb012b3 | 148 | q->limits.bounce_pfn = max(max_low_pfn, b_pfn); |
86db1e29 | 149 | #else |
6728cb0e | 150 | if (b_pfn < blk_max_low_pfn) |
86db1e29 | 151 | dma = 1; |
c49825fa | 152 | q->limits.bounce_pfn = b_pfn; |
260a67a9 | 153 | #endif |
86db1e29 JA |
154 | if (dma) { |
155 | init_emergency_isa_pool(); | |
156 | q->bounce_gfp = GFP_NOIO | GFP_DMA; | |
260a67a9 | 157 | q->limits.bounce_pfn = b_pfn; |
86db1e29 JA |
158 | } |
159 | } | |
86db1e29 JA |
160 | EXPORT_SYMBOL(blk_queue_bounce_limit); |
161 | ||
162 | /** | |
ca369d51 MP |
163 | * blk_queue_max_hw_sectors - set max sectors for a request for this queue |
164 | * @q: the request queue for the device | |
2800aac1 | 165 | * @max_hw_sectors: max hardware sectors in the usual 512b unit |
86db1e29 JA |
166 | * |
167 | * Description: | |
2800aac1 MP |
168 | * Enables a low level driver to set a hard upper limit, |
169 | * max_hw_sectors, on the size of requests. max_hw_sectors is set by | |
4f258a46 MP |
170 | * the device driver based upon the capabilities of the I/O |
171 | * controller. | |
2800aac1 | 172 | * |
ca369d51 MP |
173 | * max_dev_sectors is a hard limit imposed by the storage device for |
174 | * READ/WRITE requests. It is set by the disk driver. | |
175 | * | |
2800aac1 MP |
176 | * max_sectors is a soft limit imposed by the block layer for |
177 | * filesystem type requests. This value can be overridden on a | |
178 | * per-device basis in /sys/block/<device>/queue/max_sectors_kb. | |
179 | * The soft limit can not exceed max_hw_sectors. | |
86db1e29 | 180 | **/ |
ca369d51 | 181 | void blk_queue_max_hw_sectors(struct request_queue *q, unsigned int max_hw_sectors) |
86db1e29 | 182 | { |
ca369d51 MP |
183 | struct queue_limits *limits = &q->limits; |
184 | unsigned int max_sectors; | |
185 | ||
09cbfeaf KS |
186 | if ((max_hw_sectors << 9) < PAGE_SIZE) { |
187 | max_hw_sectors = 1 << (PAGE_SHIFT - 9); | |
24c03d47 | 188 | printk(KERN_INFO "%s: set to minimum %d\n", |
2800aac1 | 189 | __func__, max_hw_sectors); |
86db1e29 JA |
190 | } |
191 | ||
30e2bc08 | 192 | limits->max_hw_sectors = max_hw_sectors; |
ca369d51 MP |
193 | max_sectors = min_not_zero(max_hw_sectors, limits->max_dev_sectors); |
194 | max_sectors = min_t(unsigned int, max_sectors, BLK_DEF_MAX_SECTORS); | |
195 | limits->max_sectors = max_sectors; | |
dc3b17cc | 196 | q->backing_dev_info->io_pages = max_sectors >> (PAGE_SHIFT - 9); |
86db1e29 | 197 | } |
086fa5ff | 198 | EXPORT_SYMBOL(blk_queue_max_hw_sectors); |
86db1e29 | 199 | |
762380ad JA |
200 | /** |
201 | * blk_queue_chunk_sectors - set size of the chunk for this queue | |
202 | * @q: the request queue for the device | |
203 | * @chunk_sectors: chunk sectors in the usual 512b unit | |
204 | * | |
205 | * Description: | |
206 | * If a driver doesn't want IOs to cross a given chunk size, it can set | |
207 | * this limit and prevent merging across chunks. Note that the chunk size | |
58a4915a JA |
208 | * must currently be a power-of-2 in sectors. Also note that the block |
209 | * layer must accept a page worth of data at any offset. So if the | |
210 | * crossing of chunks is a hard limitation in the driver, it must still be | |
211 | * prepared to split single page bios. | |
762380ad JA |
212 | **/ |
213 | void blk_queue_chunk_sectors(struct request_queue *q, unsigned int chunk_sectors) | |
214 | { | |
215 | BUG_ON(!is_power_of_2(chunk_sectors)); | |
216 | q->limits.chunk_sectors = chunk_sectors; | |
217 | } | |
218 | EXPORT_SYMBOL(blk_queue_chunk_sectors); | |
219 | ||
67efc925 CH |
220 | /** |
221 | * blk_queue_max_discard_sectors - set max sectors for a single discard | |
222 | * @q: the request queue for the device | |
c7ebf065 | 223 | * @max_discard_sectors: maximum number of sectors to discard |
67efc925 CH |
224 | **/ |
225 | void blk_queue_max_discard_sectors(struct request_queue *q, | |
226 | unsigned int max_discard_sectors) | |
227 | { | |
0034af03 | 228 | q->limits.max_hw_discard_sectors = max_discard_sectors; |
67efc925 CH |
229 | q->limits.max_discard_sectors = max_discard_sectors; |
230 | } | |
231 | EXPORT_SYMBOL(blk_queue_max_discard_sectors); | |
232 | ||
4363ac7c MP |
233 | /** |
234 | * blk_queue_max_write_same_sectors - set max sectors for a single write same | |
235 | * @q: the request queue for the device | |
236 | * @max_write_same_sectors: maximum number of sectors to write per command | |
237 | **/ | |
238 | void blk_queue_max_write_same_sectors(struct request_queue *q, | |
239 | unsigned int max_write_same_sectors) | |
240 | { | |
241 | q->limits.max_write_same_sectors = max_write_same_sectors; | |
242 | } | |
243 | EXPORT_SYMBOL(blk_queue_max_write_same_sectors); | |
244 | ||
a6f0788e CK |
245 | /** |
246 | * blk_queue_max_write_zeroes_sectors - set max sectors for a single | |
247 | * write zeroes | |
248 | * @q: the request queue for the device | |
249 | * @max_write_zeroes_sectors: maximum number of sectors to write per command | |
250 | **/ | |
251 | void blk_queue_max_write_zeroes_sectors(struct request_queue *q, | |
252 | unsigned int max_write_zeroes_sectors) | |
253 | { | |
254 | q->limits.max_write_zeroes_sectors = max_write_zeroes_sectors; | |
255 | } | |
256 | EXPORT_SYMBOL(blk_queue_max_write_zeroes_sectors); | |
257 | ||
86db1e29 | 258 | /** |
8a78362c | 259 | * blk_queue_max_segments - set max hw segments for a request for this queue |
86db1e29 JA |
260 | * @q: the request queue for the device |
261 | * @max_segments: max number of segments | |
262 | * | |
263 | * Description: | |
264 | * Enables a low level driver to set an upper limit on the number of | |
8a78362c | 265 | * hw data segments in a request. |
86db1e29 | 266 | **/ |
8a78362c | 267 | void blk_queue_max_segments(struct request_queue *q, unsigned short max_segments) |
86db1e29 JA |
268 | { |
269 | if (!max_segments) { | |
270 | max_segments = 1; | |
24c03d47 HH |
271 | printk(KERN_INFO "%s: set to minimum %d\n", |
272 | __func__, max_segments); | |
86db1e29 JA |
273 | } |
274 | ||
8a78362c | 275 | q->limits.max_segments = max_segments; |
86db1e29 | 276 | } |
8a78362c | 277 | EXPORT_SYMBOL(blk_queue_max_segments); |
86db1e29 | 278 | |
1e739730 CH |
279 | /** |
280 | * blk_queue_max_discard_segments - set max segments for discard requests | |
281 | * @q: the request queue for the device | |
282 | * @max_segments: max number of segments | |
283 | * | |
284 | * Description: | |
285 | * Enables a low level driver to set an upper limit on the number of | |
286 | * segments in a discard request. | |
287 | **/ | |
288 | void blk_queue_max_discard_segments(struct request_queue *q, | |
289 | unsigned short max_segments) | |
290 | { | |
291 | q->limits.max_discard_segments = max_segments; | |
292 | } | |
293 | EXPORT_SYMBOL_GPL(blk_queue_max_discard_segments); | |
294 | ||
86db1e29 JA |
295 | /** |
296 | * blk_queue_max_segment_size - set max segment size for blk_rq_map_sg | |
297 | * @q: the request queue for the device | |
298 | * @max_size: max size of segment in bytes | |
299 | * | |
300 | * Description: | |
301 | * Enables a low level driver to set an upper limit on the size of a | |
302 | * coalesced segment | |
303 | **/ | |
304 | void blk_queue_max_segment_size(struct request_queue *q, unsigned int max_size) | |
305 | { | |
09cbfeaf KS |
306 | if (max_size < PAGE_SIZE) { |
307 | max_size = PAGE_SIZE; | |
24c03d47 HH |
308 | printk(KERN_INFO "%s: set to minimum %d\n", |
309 | __func__, max_size); | |
86db1e29 JA |
310 | } |
311 | ||
025146e1 | 312 | q->limits.max_segment_size = max_size; |
86db1e29 | 313 | } |
86db1e29 JA |
314 | EXPORT_SYMBOL(blk_queue_max_segment_size); |
315 | ||
316 | /** | |
e1defc4f | 317 | * blk_queue_logical_block_size - set logical block size for the queue |
86db1e29 | 318 | * @q: the request queue for the device |
e1defc4f | 319 | * @size: the logical block size, in bytes |
86db1e29 JA |
320 | * |
321 | * Description: | |
e1defc4f MP |
322 | * This should be set to the lowest possible block size that the |
323 | * storage device can address. The default of 512 covers most | |
324 | * hardware. | |
86db1e29 | 325 | **/ |
e1defc4f | 326 | void blk_queue_logical_block_size(struct request_queue *q, unsigned short size) |
86db1e29 | 327 | { |
025146e1 | 328 | q->limits.logical_block_size = size; |
c72758f3 MP |
329 | |
330 | if (q->limits.physical_block_size < size) | |
331 | q->limits.physical_block_size = size; | |
332 | ||
333 | if (q->limits.io_min < q->limits.physical_block_size) | |
334 | q->limits.io_min = q->limits.physical_block_size; | |
86db1e29 | 335 | } |
e1defc4f | 336 | EXPORT_SYMBOL(blk_queue_logical_block_size); |
86db1e29 | 337 | |
c72758f3 MP |
338 | /** |
339 | * blk_queue_physical_block_size - set physical block size for the queue | |
340 | * @q: the request queue for the device | |
341 | * @size: the physical block size, in bytes | |
342 | * | |
343 | * Description: | |
344 | * This should be set to the lowest possible sector size that the | |
345 | * hardware can operate on without reverting to read-modify-write | |
346 | * operations. | |
347 | */ | |
892b6f90 | 348 | void blk_queue_physical_block_size(struct request_queue *q, unsigned int size) |
c72758f3 MP |
349 | { |
350 | q->limits.physical_block_size = size; | |
351 | ||
352 | if (q->limits.physical_block_size < q->limits.logical_block_size) | |
353 | q->limits.physical_block_size = q->limits.logical_block_size; | |
354 | ||
355 | if (q->limits.io_min < q->limits.physical_block_size) | |
356 | q->limits.io_min = q->limits.physical_block_size; | |
357 | } | |
358 | EXPORT_SYMBOL(blk_queue_physical_block_size); | |
359 | ||
360 | /** | |
361 | * blk_queue_alignment_offset - set physical block alignment offset | |
362 | * @q: the request queue for the device | |
8ebf9756 | 363 | * @offset: alignment offset in bytes |
c72758f3 MP |
364 | * |
365 | * Description: | |
366 | * Some devices are naturally misaligned to compensate for things like | |
367 | * the legacy DOS partition table 63-sector offset. Low-level drivers | |
368 | * should call this function for devices whose first sector is not | |
369 | * naturally aligned. | |
370 | */ | |
371 | void blk_queue_alignment_offset(struct request_queue *q, unsigned int offset) | |
372 | { | |
373 | q->limits.alignment_offset = | |
374 | offset & (q->limits.physical_block_size - 1); | |
375 | q->limits.misaligned = 0; | |
376 | } | |
377 | EXPORT_SYMBOL(blk_queue_alignment_offset); | |
378 | ||
7c958e32 MP |
379 | /** |
380 | * blk_limits_io_min - set minimum request size for a device | |
381 | * @limits: the queue limits | |
382 | * @min: smallest I/O size in bytes | |
383 | * | |
384 | * Description: | |
385 | * Some devices have an internal block size bigger than the reported | |
386 | * hardware sector size. This function can be used to signal the | |
387 | * smallest I/O the device can perform without incurring a performance | |
388 | * penalty. | |
389 | */ | |
390 | void blk_limits_io_min(struct queue_limits *limits, unsigned int min) | |
391 | { | |
392 | limits->io_min = min; | |
393 | ||
394 | if (limits->io_min < limits->logical_block_size) | |
395 | limits->io_min = limits->logical_block_size; | |
396 | ||
397 | if (limits->io_min < limits->physical_block_size) | |
398 | limits->io_min = limits->physical_block_size; | |
399 | } | |
400 | EXPORT_SYMBOL(blk_limits_io_min); | |
401 | ||
c72758f3 MP |
402 | /** |
403 | * blk_queue_io_min - set minimum request size for the queue | |
404 | * @q: the request queue for the device | |
8ebf9756 | 405 | * @min: smallest I/O size in bytes |
c72758f3 MP |
406 | * |
407 | * Description: | |
7e5f5fb0 MP |
408 | * Storage devices may report a granularity or preferred minimum I/O |
409 | * size which is the smallest request the device can perform without | |
410 | * incurring a performance penalty. For disk drives this is often the | |
411 | * physical block size. For RAID arrays it is often the stripe chunk | |
412 | * size. A properly aligned multiple of minimum_io_size is the | |
413 | * preferred request size for workloads where a high number of I/O | |
414 | * operations is desired. | |
c72758f3 MP |
415 | */ |
416 | void blk_queue_io_min(struct request_queue *q, unsigned int min) | |
417 | { | |
7c958e32 | 418 | blk_limits_io_min(&q->limits, min); |
c72758f3 MP |
419 | } |
420 | EXPORT_SYMBOL(blk_queue_io_min); | |
421 | ||
3c5820c7 MP |
422 | /** |
423 | * blk_limits_io_opt - set optimal request size for a device | |
424 | * @limits: the queue limits | |
425 | * @opt: smallest I/O size in bytes | |
426 | * | |
427 | * Description: | |
428 | * Storage devices may report an optimal I/O size, which is the | |
429 | * device's preferred unit for sustained I/O. This is rarely reported | |
430 | * for disk drives. For RAID arrays it is usually the stripe width or | |
431 | * the internal track size. A properly aligned multiple of | |
432 | * optimal_io_size is the preferred request size for workloads where | |
433 | * sustained throughput is desired. | |
434 | */ | |
435 | void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt) | |
436 | { | |
437 | limits->io_opt = opt; | |
438 | } | |
439 | EXPORT_SYMBOL(blk_limits_io_opt); | |
440 | ||
c72758f3 MP |
441 | /** |
442 | * blk_queue_io_opt - set optimal request size for the queue | |
443 | * @q: the request queue for the device | |
8ebf9756 | 444 | * @opt: optimal request size in bytes |
c72758f3 MP |
445 | * |
446 | * Description: | |
7e5f5fb0 MP |
447 | * Storage devices may report an optimal I/O size, which is the |
448 | * device's preferred unit for sustained I/O. This is rarely reported | |
449 | * for disk drives. For RAID arrays it is usually the stripe width or | |
450 | * the internal track size. A properly aligned multiple of | |
451 | * optimal_io_size is the preferred request size for workloads where | |
452 | * sustained throughput is desired. | |
c72758f3 MP |
453 | */ |
454 | void blk_queue_io_opt(struct request_queue *q, unsigned int opt) | |
455 | { | |
3c5820c7 | 456 | blk_limits_io_opt(&q->limits, opt); |
c72758f3 MP |
457 | } |
458 | EXPORT_SYMBOL(blk_queue_io_opt); | |
459 | ||
86db1e29 JA |
460 | /** |
461 | * blk_queue_stack_limits - inherit underlying queue limits for stacked drivers | |
462 | * @t: the stacking driver (top) | |
463 | * @b: the underlying device (bottom) | |
464 | **/ | |
465 | void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b) | |
466 | { | |
fef24667 | 467 | blk_stack_limits(&t->limits, &b->limits, 0); |
86db1e29 | 468 | } |
86db1e29 JA |
469 | EXPORT_SYMBOL(blk_queue_stack_limits); |
470 | ||
c72758f3 MP |
471 | /** |
472 | * blk_stack_limits - adjust queue_limits for stacked devices | |
81744ee4 MP |
473 | * @t: the stacking driver limits (top device) |
474 | * @b: the underlying queue limits (bottom, component device) | |
e03a72e1 | 475 | * @start: first data sector within component device |
c72758f3 MP |
476 | * |
477 | * Description: | |
81744ee4 MP |
478 | * This function is used by stacking drivers like MD and DM to ensure |
479 | * that all component devices have compatible block sizes and | |
480 | * alignments. The stacking driver must provide a queue_limits | |
481 | * struct (top) and then iteratively call the stacking function for | |
482 | * all component (bottom) devices. The stacking function will | |
483 | * attempt to combine the values and ensure proper alignment. | |
484 | * | |
485 | * Returns 0 if the top and bottom queue_limits are compatible. The | |
486 | * top device's block sizes and alignment offsets may be adjusted to | |
487 | * ensure alignment with the bottom device. If no compatible sizes | |
488 | * and alignments exist, -1 is returned and the resulting top | |
489 | * queue_limits will have the misaligned flag set to indicate that | |
490 | * the alignment_offset is undefined. | |
c72758f3 MP |
491 | */ |
492 | int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, | |
e03a72e1 | 493 | sector_t start) |
c72758f3 | 494 | { |
e03a72e1 | 495 | unsigned int top, bottom, alignment, ret = 0; |
86b37281 | 496 | |
c72758f3 MP |
497 | t->max_sectors = min_not_zero(t->max_sectors, b->max_sectors); |
498 | t->max_hw_sectors = min_not_zero(t->max_hw_sectors, b->max_hw_sectors); | |
ca369d51 | 499 | t->max_dev_sectors = min_not_zero(t->max_dev_sectors, b->max_dev_sectors); |
4363ac7c MP |
500 | t->max_write_same_sectors = min(t->max_write_same_sectors, |
501 | b->max_write_same_sectors); | |
a6f0788e CK |
502 | t->max_write_zeroes_sectors = min(t->max_write_zeroes_sectors, |
503 | b->max_write_zeroes_sectors); | |
77634f33 | 504 | t->bounce_pfn = min_not_zero(t->bounce_pfn, b->bounce_pfn); |
c72758f3 MP |
505 | |
506 | t->seg_boundary_mask = min_not_zero(t->seg_boundary_mask, | |
507 | b->seg_boundary_mask); | |
03100aad KB |
508 | t->virt_boundary_mask = min_not_zero(t->virt_boundary_mask, |
509 | b->virt_boundary_mask); | |
c72758f3 | 510 | |
8a78362c | 511 | t->max_segments = min_not_zero(t->max_segments, b->max_segments); |
1e739730 CH |
512 | t->max_discard_segments = min_not_zero(t->max_discard_segments, |
513 | b->max_discard_segments); | |
13f05c8d MP |
514 | t->max_integrity_segments = min_not_zero(t->max_integrity_segments, |
515 | b->max_integrity_segments); | |
c72758f3 MP |
516 | |
517 | t->max_segment_size = min_not_zero(t->max_segment_size, | |
518 | b->max_segment_size); | |
519 | ||
fe0b393f MP |
520 | t->misaligned |= b->misaligned; |
521 | ||
e03a72e1 | 522 | alignment = queue_limit_alignment_offset(b, start); |
9504e086 | 523 | |
81744ee4 MP |
524 | /* Bottom device has different alignment. Check that it is |
525 | * compatible with the current top alignment. | |
526 | */ | |
9504e086 MP |
527 | if (t->alignment_offset != alignment) { |
528 | ||
529 | top = max(t->physical_block_size, t->io_min) | |
530 | + t->alignment_offset; | |
81744ee4 | 531 | bottom = max(b->physical_block_size, b->io_min) + alignment; |
9504e086 | 532 | |
81744ee4 | 533 | /* Verify that top and bottom intervals line up */ |
b8839b8c | 534 | if (max(top, bottom) % min(top, bottom)) { |
9504e086 | 535 | t->misaligned = 1; |
fe0b393f MP |
536 | ret = -1; |
537 | } | |
9504e086 MP |
538 | } |
539 | ||
c72758f3 MP |
540 | t->logical_block_size = max(t->logical_block_size, |
541 | b->logical_block_size); | |
542 | ||
543 | t->physical_block_size = max(t->physical_block_size, | |
544 | b->physical_block_size); | |
545 | ||
546 | t->io_min = max(t->io_min, b->io_min); | |
e9637415 | 547 | t->io_opt = lcm_not_zero(t->io_opt, b->io_opt); |
9504e086 | 548 | |
81744ee4 | 549 | /* Physical block size a multiple of the logical block size? */ |
9504e086 MP |
550 | if (t->physical_block_size & (t->logical_block_size - 1)) { |
551 | t->physical_block_size = t->logical_block_size; | |
c72758f3 | 552 | t->misaligned = 1; |
fe0b393f | 553 | ret = -1; |
86b37281 MP |
554 | } |
555 | ||
81744ee4 | 556 | /* Minimum I/O a multiple of the physical block size? */ |
9504e086 MP |
557 | if (t->io_min & (t->physical_block_size - 1)) { |
558 | t->io_min = t->physical_block_size; | |
559 | t->misaligned = 1; | |
fe0b393f | 560 | ret = -1; |
c72758f3 MP |
561 | } |
562 | ||
81744ee4 | 563 | /* Optimal I/O a multiple of the physical block size? */ |
9504e086 MP |
564 | if (t->io_opt & (t->physical_block_size - 1)) { |
565 | t->io_opt = 0; | |
566 | t->misaligned = 1; | |
fe0b393f | 567 | ret = -1; |
9504e086 | 568 | } |
c72758f3 | 569 | |
c78afc62 KO |
570 | t->raid_partial_stripes_expensive = |
571 | max(t->raid_partial_stripes_expensive, | |
572 | b->raid_partial_stripes_expensive); | |
573 | ||
81744ee4 | 574 | /* Find lowest common alignment_offset */ |
e9637415 | 575 | t->alignment_offset = lcm_not_zero(t->alignment_offset, alignment) |
b8839b8c | 576 | % max(t->physical_block_size, t->io_min); |
86b37281 | 577 | |
81744ee4 | 578 | /* Verify that new alignment_offset is on a logical block boundary */ |
fe0b393f | 579 | if (t->alignment_offset & (t->logical_block_size - 1)) { |
c72758f3 | 580 | t->misaligned = 1; |
fe0b393f MP |
581 | ret = -1; |
582 | } | |
c72758f3 | 583 | |
9504e086 MP |
584 | /* Discard alignment and granularity */ |
585 | if (b->discard_granularity) { | |
e03a72e1 | 586 | alignment = queue_limit_discard_alignment(b, start); |
9504e086 MP |
587 | |
588 | if (t->discard_granularity != 0 && | |
589 | t->discard_alignment != alignment) { | |
590 | top = t->discard_granularity + t->discard_alignment; | |
591 | bottom = b->discard_granularity + alignment; | |
70dd5bf3 | 592 | |
9504e086 | 593 | /* Verify that top and bottom intervals line up */ |
8dd2cb7e | 594 | if ((max(top, bottom) % min(top, bottom)) != 0) |
9504e086 MP |
595 | t->discard_misaligned = 1; |
596 | } | |
597 | ||
81744ee4 MP |
598 | t->max_discard_sectors = min_not_zero(t->max_discard_sectors, |
599 | b->max_discard_sectors); | |
0034af03 JA |
600 | t->max_hw_discard_sectors = min_not_zero(t->max_hw_discard_sectors, |
601 | b->max_hw_discard_sectors); | |
9504e086 MP |
602 | t->discard_granularity = max(t->discard_granularity, |
603 | b->discard_granularity); | |
e9637415 | 604 | t->discard_alignment = lcm_not_zero(t->discard_alignment, alignment) % |
8dd2cb7e | 605 | t->discard_granularity; |
9504e086 | 606 | } |
70dd5bf3 | 607 | |
987b3b26 HR |
608 | if (b->chunk_sectors) |
609 | t->chunk_sectors = min_not_zero(t->chunk_sectors, | |
610 | b->chunk_sectors); | |
611 | ||
fe0b393f | 612 | return ret; |
c72758f3 | 613 | } |
5d85d324 | 614 | EXPORT_SYMBOL(blk_stack_limits); |
c72758f3 | 615 | |
17be8c24 MP |
616 | /** |
617 | * bdev_stack_limits - adjust queue limits for stacked drivers | |
618 | * @t: the stacking driver limits (top device) | |
619 | * @bdev: the component block_device (bottom) | |
620 | * @start: first data sector within component device | |
621 | * | |
622 | * Description: | |
623 | * Merges queue limits for a top device and a block_device. Returns | |
624 | * 0 if alignment didn't change. Returns -1 if adding the bottom | |
625 | * device caused misalignment. | |
626 | */ | |
627 | int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev, | |
628 | sector_t start) | |
629 | { | |
630 | struct request_queue *bq = bdev_get_queue(bdev); | |
631 | ||
632 | start += get_start_sect(bdev); | |
633 | ||
e03a72e1 | 634 | return blk_stack_limits(t, &bq->limits, start); |
17be8c24 MP |
635 | } |
636 | EXPORT_SYMBOL(bdev_stack_limits); | |
637 | ||
c72758f3 MP |
638 | /** |
639 | * disk_stack_limits - adjust queue limits for stacked drivers | |
77634f33 | 640 | * @disk: MD/DM gendisk (top) |
c72758f3 MP |
641 | * @bdev: the underlying block device (bottom) |
642 | * @offset: offset to beginning of data within component device | |
643 | * | |
644 | * Description: | |
e03a72e1 MP |
645 | * Merges the limits for a top level gendisk and a bottom level |
646 | * block_device. | |
c72758f3 MP |
647 | */ |
648 | void disk_stack_limits(struct gendisk *disk, struct block_device *bdev, | |
649 | sector_t offset) | |
650 | { | |
651 | struct request_queue *t = disk->queue; | |
c72758f3 | 652 | |
e03a72e1 | 653 | if (bdev_stack_limits(&t->limits, bdev, offset >> 9) < 0) { |
c72758f3 MP |
654 | char top[BDEVNAME_SIZE], bottom[BDEVNAME_SIZE]; |
655 | ||
656 | disk_name(disk, 0, top); | |
657 | bdevname(bdev, bottom); | |
658 | ||
659 | printk(KERN_NOTICE "%s: Warning: Device %s is misaligned\n", | |
660 | top, bottom); | |
661 | } | |
c72758f3 MP |
662 | } |
663 | EXPORT_SYMBOL(disk_stack_limits); | |
664 | ||
e3790c7d TH |
665 | /** |
666 | * blk_queue_dma_pad - set pad mask | |
667 | * @q: the request queue for the device | |
668 | * @mask: pad mask | |
669 | * | |
27f8221a | 670 | * Set dma pad mask. |
e3790c7d | 671 | * |
27f8221a FT |
672 | * Appending pad buffer to a request modifies the last entry of a |
673 | * scatter list such that it includes the pad buffer. | |
e3790c7d TH |
674 | **/ |
675 | void blk_queue_dma_pad(struct request_queue *q, unsigned int mask) | |
676 | { | |
677 | q->dma_pad_mask = mask; | |
678 | } | |
679 | EXPORT_SYMBOL(blk_queue_dma_pad); | |
680 | ||
27f8221a FT |
681 | /** |
682 | * blk_queue_update_dma_pad - update pad mask | |
683 | * @q: the request queue for the device | |
684 | * @mask: pad mask | |
685 | * | |
686 | * Update dma pad mask. | |
687 | * | |
688 | * Appending pad buffer to a request modifies the last entry of a | |
689 | * scatter list such that it includes the pad buffer. | |
690 | **/ | |
691 | void blk_queue_update_dma_pad(struct request_queue *q, unsigned int mask) | |
692 | { | |
693 | if (mask > q->dma_pad_mask) | |
694 | q->dma_pad_mask = mask; | |
695 | } | |
696 | EXPORT_SYMBOL(blk_queue_update_dma_pad); | |
697 | ||
86db1e29 JA |
698 | /** |
699 | * blk_queue_dma_drain - Set up a drain buffer for excess dma. | |
86db1e29 | 700 | * @q: the request queue for the device |
2fb98e84 | 701 | * @dma_drain_needed: fn which returns non-zero if drain is necessary |
86db1e29 JA |
702 | * @buf: physically contiguous buffer |
703 | * @size: size of the buffer in bytes | |
704 | * | |
705 | * Some devices have excess DMA problems and can't simply discard (or | |
706 | * zero fill) the unwanted piece of the transfer. They have to have a | |
707 | * real area of memory to transfer it into. The use case for this is | |
708 | * ATAPI devices in DMA mode. If the packet command causes a transfer | |
709 | * bigger than the transfer size some HBAs will lock up if there | |
710 | * aren't DMA elements to contain the excess transfer. What this API | |
711 | * does is adjust the queue so that the buf is always appended | |
712 | * silently to the scatterlist. | |
713 | * | |
8a78362c MP |
714 | * Note: This routine adjusts max_hw_segments to make room for appending |
715 | * the drain buffer. If you call blk_queue_max_segments() after calling | |
716 | * this routine, you must set the limit to one fewer than your device | |
717 | * can support otherwise there won't be room for the drain buffer. | |
86db1e29 | 718 | */ |
448da4d2 | 719 | int blk_queue_dma_drain(struct request_queue *q, |
2fb98e84 TH |
720 | dma_drain_needed_fn *dma_drain_needed, |
721 | void *buf, unsigned int size) | |
86db1e29 | 722 | { |
8a78362c | 723 | if (queue_max_segments(q) < 2) |
86db1e29 JA |
724 | return -EINVAL; |
725 | /* make room for appending the drain */ | |
8a78362c | 726 | blk_queue_max_segments(q, queue_max_segments(q) - 1); |
2fb98e84 | 727 | q->dma_drain_needed = dma_drain_needed; |
86db1e29 JA |
728 | q->dma_drain_buffer = buf; |
729 | q->dma_drain_size = size; | |
730 | ||
731 | return 0; | |
732 | } | |
86db1e29 JA |
733 | EXPORT_SYMBOL_GPL(blk_queue_dma_drain); |
734 | ||
735 | /** | |
736 | * blk_queue_segment_boundary - set boundary rules for segment merging | |
737 | * @q: the request queue for the device | |
738 | * @mask: the memory boundary mask | |
739 | **/ | |
740 | void blk_queue_segment_boundary(struct request_queue *q, unsigned long mask) | |
741 | { | |
09cbfeaf KS |
742 | if (mask < PAGE_SIZE - 1) { |
743 | mask = PAGE_SIZE - 1; | |
24c03d47 HH |
744 | printk(KERN_INFO "%s: set to minimum %lx\n", |
745 | __func__, mask); | |
86db1e29 JA |
746 | } |
747 | ||
025146e1 | 748 | q->limits.seg_boundary_mask = mask; |
86db1e29 | 749 | } |
86db1e29 JA |
750 | EXPORT_SYMBOL(blk_queue_segment_boundary); |
751 | ||
03100aad KB |
752 | /** |
753 | * blk_queue_virt_boundary - set boundary rules for bio merging | |
754 | * @q: the request queue for the device | |
755 | * @mask: the memory boundary mask | |
756 | **/ | |
757 | void blk_queue_virt_boundary(struct request_queue *q, unsigned long mask) | |
758 | { | |
759 | q->limits.virt_boundary_mask = mask; | |
760 | } | |
761 | EXPORT_SYMBOL(blk_queue_virt_boundary); | |
762 | ||
86db1e29 JA |
763 | /** |
764 | * blk_queue_dma_alignment - set dma length and memory alignment | |
765 | * @q: the request queue for the device | |
766 | * @mask: alignment mask | |
767 | * | |
768 | * description: | |
710027a4 | 769 | * set required memory and length alignment for direct dma transactions. |
8feb4d20 | 770 | * this is used when building direct io requests for the queue. |
86db1e29 JA |
771 | * |
772 | **/ | |
773 | void blk_queue_dma_alignment(struct request_queue *q, int mask) | |
774 | { | |
775 | q->dma_alignment = mask; | |
776 | } | |
86db1e29 JA |
777 | EXPORT_SYMBOL(blk_queue_dma_alignment); |
778 | ||
779 | /** | |
780 | * blk_queue_update_dma_alignment - update dma length and memory alignment | |
781 | * @q: the request queue for the device | |
782 | * @mask: alignment mask | |
783 | * | |
784 | * description: | |
710027a4 | 785 | * update required memory and length alignment for direct dma transactions. |
86db1e29 JA |
786 | * If the requested alignment is larger than the current alignment, then |
787 | * the current queue alignment is updated to the new value, otherwise it | |
788 | * is left alone. The design of this is to allow multiple objects | |
789 | * (driver, device, transport etc) to set their respective | |
790 | * alignments without having them interfere. | |
791 | * | |
792 | **/ | |
793 | void blk_queue_update_dma_alignment(struct request_queue *q, int mask) | |
794 | { | |
795 | BUG_ON(mask > PAGE_SIZE); | |
796 | ||
797 | if (mask > q->dma_alignment) | |
798 | q->dma_alignment = mask; | |
799 | } | |
86db1e29 JA |
800 | EXPORT_SYMBOL(blk_queue_update_dma_alignment); |
801 | ||
d278d4a8 JA |
802 | /** |
803 | * blk_set_queue_depth - tell the block layer about the device queue depth | |
804 | * @q: the request queue for the device | |
805 | * @depth: queue depth | |
806 | * | |
807 | */ | |
808 | void blk_set_queue_depth(struct request_queue *q, unsigned int depth) | |
809 | { | |
810 | q->queue_depth = depth; | |
a7905043 | 811 | wbt_set_queue_depth(q, depth); |
d278d4a8 JA |
812 | } |
813 | EXPORT_SYMBOL(blk_set_queue_depth); | |
814 | ||
93e9d8e8 JA |
815 | /** |
816 | * blk_queue_write_cache - configure queue's write cache | |
817 | * @q: the request queue for the device | |
818 | * @wc: write back cache on or off | |
819 | * @fua: device supports FUA writes, if true | |
820 | * | |
821 | * Tell the block layer about the write cache of @q. | |
822 | */ | |
823 | void blk_queue_write_cache(struct request_queue *q, bool wc, bool fua) | |
824 | { | |
c888a8f9 | 825 | if (wc) |
57d74df9 | 826 | blk_queue_flag_set(QUEUE_FLAG_WC, q); |
c888a8f9 | 827 | else |
57d74df9 | 828 | blk_queue_flag_clear(QUEUE_FLAG_WC, q); |
c888a8f9 | 829 | if (fua) |
57d74df9 | 830 | blk_queue_flag_set(QUEUE_FLAG_FUA, q); |
c888a8f9 | 831 | else |
57d74df9 | 832 | blk_queue_flag_clear(QUEUE_FLAG_FUA, q); |
87760e5e | 833 | |
a7905043 | 834 | wbt_set_write_cache(q, test_bit(QUEUE_FLAG_WC, &q->queue_flags)); |
93e9d8e8 JA |
835 | } |
836 | EXPORT_SYMBOL_GPL(blk_queue_write_cache); | |
837 | ||
aeb3d3a8 | 838 | static int __init blk_settings_init(void) |
86db1e29 JA |
839 | { |
840 | blk_max_low_pfn = max_low_pfn - 1; | |
841 | blk_max_pfn = max_pfn - 1; | |
842 | return 0; | |
843 | } | |
844 | subsys_initcall(blk_settings_init); |