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Commit 9f7e45d83ef09a481cbc4172849bd1fcf88a39ed

Authored by Santosh Shilimkar
Committed by Russell King
1 parent 4dcfa60071
Exists in smarc-imx_3.14.28_1.0.0_ga and in 1 other branch imx_3.14.28_1.0.0_ga

ARM: 7794/1: block: Rename parameter dma_mask to max_addr for blk_queue_bounce_limit() 

The blk_queue_bounce_limit() API parameter 'dma_mask' is actually the
maximum address the device can handle rather than a dma_mask. Rename
it accordingly to avoid it being interpreted as dma_mask.

No functional change.

The idea is to fix the bad assumptions about dma_mask wherever it could
be miss-interpreted.

Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Showing 1 changed file with 4 additions and 4 deletions Inline Diff

block/blk-settings.c
Diff comments   View file @ 9f7e45d
1 /* 1 /*
2 * Functions related to setting various queue properties from drivers 2 * Functions related to setting various queue properties from drivers
3 */ 3 */
4 #include <linux/kernel.h> 4 #include <linux/kernel.h>
5 #include <linux/module.h> 5 #include <linux/module.h>
6 #include <linux/init.h> 6 #include <linux/init.h>
7 #include <linux/bio.h> 7 #include <linux/bio.h>
8 #include <linux/blkdev.h> 8 #include <linux/blkdev.h>
9 #include <linux/bootmem.h> /* for max_pfn/max_low_pfn */ 9 #include <linux/bootmem.h> /* for max_pfn/max_low_pfn */
10 #include <linux/gcd.h> 10 #include <linux/gcd.h>
11 #include <linux/lcm.h> 11 #include <linux/lcm.h>
12 #include <linux/jiffies.h> 12 #include <linux/jiffies.h>
13 #include <linux/gfp.h> 13 #include <linux/gfp.h>
14 14
15 #include "blk.h" 15 #include "blk.h"
16 16
17 unsigned long blk_max_low_pfn; 17 unsigned long blk_max_low_pfn;
18 EXPORT_SYMBOL(blk_max_low_pfn); 18 EXPORT_SYMBOL(blk_max_low_pfn);
19 19
20 unsigned long blk_max_pfn; 20 unsigned long blk_max_pfn;
21 21
22 /** 22 /**
23 * blk_queue_prep_rq - set a prepare_request function for queue 23 * blk_queue_prep_rq - set a prepare_request function for queue
24 * @q: queue 24 * @q: queue
25 * @pfn: prepare_request function 25 * @pfn: prepare_request function
26 * 26 *
27 * It's possible for a queue to register a prepare_request callback which 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 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 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. 30 * cdb from the request data for instance.
31 * 31 *
32 */ 32 */
33 void blk_queue_prep_rq(struct request_queue *q, prep_rq_fn *pfn) 33 void blk_queue_prep_rq(struct request_queue *q, prep_rq_fn *pfn)
34 { 34 {
35 q->prep_rq_fn = pfn; 35 q->prep_rq_fn = pfn;
36 } 36 }
37 EXPORT_SYMBOL(blk_queue_prep_rq); 37 EXPORT_SYMBOL(blk_queue_prep_rq);
38 38
39 /** 39 /**
40 * blk_queue_unprep_rq - set an unprepare_request function for queue 40 * blk_queue_unprep_rq - set an unprepare_request function for queue
41 * @q: queue 41 * @q: queue
42 * @ufn: unprepare_request function 42 * @ufn: unprepare_request function
43 * 43 *
44 * It's possible for a queue to register an unprepare_request callback 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 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 46 * of the function is to deallocate any data that was allocated in the
47 * prepare_request callback. 47 * prepare_request callback.
48 * 48 *
49 */ 49 */
50 void blk_queue_unprep_rq(struct request_queue *q, unprep_rq_fn *ufn) 50 void blk_queue_unprep_rq(struct request_queue *q, unprep_rq_fn *ufn)
51 { 51 {
52 q->unprep_rq_fn = ufn; 52 q->unprep_rq_fn = ufn;
53 } 53 }
54 EXPORT_SYMBOL(blk_queue_unprep_rq); 54 EXPORT_SYMBOL(blk_queue_unprep_rq);
55 55
56 /** 56 /**
57 * blk_queue_merge_bvec - set a merge_bvec function for queue 57 * blk_queue_merge_bvec - set a merge_bvec function for queue
58 * @q: queue 58 * @q: queue
59 * @mbfn: merge_bvec_fn 59 * @mbfn: merge_bvec_fn
60 * 60 *
61 * Usually queues have static limitations on the max sectors or segments that 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 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 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 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 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 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 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 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 69 * no merge_bvec_fn is defined for a queue, and only the fixed limits are
70 * honored. 70 * honored.
71 */ 71 */
72 void blk_queue_merge_bvec(struct request_queue *q, merge_bvec_fn *mbfn) 72 void blk_queue_merge_bvec(struct request_queue *q, merge_bvec_fn *mbfn)
73 { 73 {
74 q->merge_bvec_fn = mbfn; 74 q->merge_bvec_fn = mbfn;
75 } 75 }
76 EXPORT_SYMBOL(blk_queue_merge_bvec); 76 EXPORT_SYMBOL(blk_queue_merge_bvec);
77 77
78 void blk_queue_softirq_done(struct request_queue *q, softirq_done_fn *fn) 78 void blk_queue_softirq_done(struct request_queue *q, softirq_done_fn *fn)
79 { 79 {
80 q->softirq_done_fn = fn; 80 q->softirq_done_fn = fn;
81 } 81 }
82 EXPORT_SYMBOL(blk_queue_softirq_done); 82 EXPORT_SYMBOL(blk_queue_softirq_done);
83 83
84 void blk_queue_rq_timeout(struct request_queue *q, unsigned int timeout) 84 void blk_queue_rq_timeout(struct request_queue *q, unsigned int timeout)
85 { 85 {
86 q->rq_timeout = timeout; 86 q->rq_timeout = timeout;
87 } 87 }
88 EXPORT_SYMBOL_GPL(blk_queue_rq_timeout); 88 EXPORT_SYMBOL_GPL(blk_queue_rq_timeout);
89 89
90 void blk_queue_rq_timed_out(struct request_queue *q, rq_timed_out_fn *fn) 90 void blk_queue_rq_timed_out(struct request_queue *q, rq_timed_out_fn *fn)
91 { 91 {
92 q->rq_timed_out_fn = fn; 92 q->rq_timed_out_fn = fn;
93 } 93 }
94 EXPORT_SYMBOL_GPL(blk_queue_rq_timed_out); 94 EXPORT_SYMBOL_GPL(blk_queue_rq_timed_out);
95 95
96 void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn) 96 void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn)
97 { 97 {
98 q->lld_busy_fn = fn; 98 q->lld_busy_fn = fn;
99 } 99 }
100 EXPORT_SYMBOL_GPL(blk_queue_lld_busy); 100 EXPORT_SYMBOL_GPL(blk_queue_lld_busy);
101 101
102 /** 102 /**
103 * blk_set_default_limits - reset limits to default values 103 * blk_set_default_limits - reset limits to default values
104 * @lim: the queue_limits structure to reset 104 * @lim: the queue_limits structure to reset
105 * 105 *
106 * Description: 106 * Description:
107 * Returns a queue_limit struct to its default state. 107 * Returns a queue_limit struct to its default state.
108 */ 108 */
109 void blk_set_default_limits(struct queue_limits *lim) 109 void blk_set_default_limits(struct queue_limits *lim)
110 { 110 {
111 lim->max_segments = BLK_MAX_SEGMENTS; 111 lim->max_segments = BLK_MAX_SEGMENTS;
112 lim->max_integrity_segments = 0; 112 lim->max_integrity_segments = 0;
113 lim->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK; 113 lim->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK;
114 lim->max_segment_size = BLK_MAX_SEGMENT_SIZE; 114 lim->max_segment_size = BLK_MAX_SEGMENT_SIZE;
115 lim->max_sectors = lim->max_hw_sectors = BLK_SAFE_MAX_SECTORS; 115 lim->max_sectors = lim->max_hw_sectors = BLK_SAFE_MAX_SECTORS;
116 lim->max_write_same_sectors = 0; 116 lim->max_write_same_sectors = 0;
117 lim->max_discard_sectors = 0; 117 lim->max_discard_sectors = 0;
118 lim->discard_granularity = 0; 118 lim->discard_granularity = 0;
119 lim->discard_alignment = 0; 119 lim->discard_alignment = 0;
120 lim->discard_misaligned = 0; 120 lim->discard_misaligned = 0;
121 lim->discard_zeroes_data = 0; 121 lim->discard_zeroes_data = 0;
122 lim->logical_block_size = lim->physical_block_size = lim->io_min = 512; 122 lim->logical_block_size = lim->physical_block_size = lim->io_min = 512;
123 lim->bounce_pfn = (unsigned long)(BLK_BOUNCE_ANY >> PAGE_SHIFT); 123 lim->bounce_pfn = (unsigned long)(BLK_BOUNCE_ANY >> PAGE_SHIFT);
124 lim->alignment_offset = 0; 124 lim->alignment_offset = 0;
125 lim->io_opt = 0; 125 lim->io_opt = 0;
126 lim->misaligned = 0; 126 lim->misaligned = 0;
127 lim->cluster = 1; 127 lim->cluster = 1;
128 } 128 }
129 EXPORT_SYMBOL(blk_set_default_limits); 129 EXPORT_SYMBOL(blk_set_default_limits);
130 130
131 /** 131 /**
132 * blk_set_stacking_limits - set default limits for stacking devices 132 * blk_set_stacking_limits - set default limits for stacking devices
133 * @lim: the queue_limits structure to reset 133 * @lim: the queue_limits structure to reset
134 * 134 *
135 * Description: 135 * Description:
136 * Returns a queue_limit struct to its default state. Should be used 136 * Returns a queue_limit struct to its default state. Should be used
137 * by stacking drivers like DM that have no internal limits. 137 * by stacking drivers like DM that have no internal limits.
138 */ 138 */
139 void blk_set_stacking_limits(struct queue_limits *lim) 139 void blk_set_stacking_limits(struct queue_limits *lim)
140 { 140 {
141 blk_set_default_limits(lim); 141 blk_set_default_limits(lim);
142 142
143 /* Inherit limits from component devices */ 143 /* Inherit limits from component devices */
144 lim->discard_zeroes_data = 1; 144 lim->discard_zeroes_data = 1;
145 lim->max_segments = USHRT_MAX; 145 lim->max_segments = USHRT_MAX;
146 lim->max_hw_sectors = UINT_MAX; 146 lim->max_hw_sectors = UINT_MAX;
147 lim->max_sectors = UINT_MAX; 147 lim->max_sectors = UINT_MAX;
148 lim->max_write_same_sectors = UINT_MAX; 148 lim->max_write_same_sectors = UINT_MAX;
149 } 149 }
150 EXPORT_SYMBOL(blk_set_stacking_limits); 150 EXPORT_SYMBOL(blk_set_stacking_limits);
151 151
152 /** 152 /**
153 * blk_queue_make_request - define an alternate make_request function for a device 153 * blk_queue_make_request - define an alternate make_request function for a device
154 * @q: the request queue for the device to be affected 154 * @q: the request queue for the device to be affected
155 * @mfn: the alternate make_request function 155 * @mfn: the alternate make_request function
156 * 156 *
157 * Description: 157 * Description:
158 * The normal way for &struct bios to be passed to a device 158 * The normal way for &struct bios to be passed to a device
159 * driver is for them to be collected into requests on a request 159 * driver is for them to be collected into requests on a request
160 * queue, and then to allow the device driver to select requests 160 * queue, and then to allow the device driver to select requests
161 * off that queue when it is ready. This works well for many block 161 * off that queue when it is ready. This works well for many block
162 * devices. However some block devices (typically virtual devices 162 * devices. However some block devices (typically virtual devices
163 * such as md or lvm) do not benefit from the processing on the 163 * such as md or lvm) do not benefit from the processing on the
164 * request queue, and are served best by having the requests passed 164 * request queue, and are served best by having the requests passed
165 * directly to them. This can be achieved by providing a function 165 * directly to them. This can be achieved by providing a function
166 * to blk_queue_make_request(). 166 * to blk_queue_make_request().
167 * 167 *
168 * Caveat: 168 * Caveat:
169 * The driver that does this *must* be able to deal appropriately 169 * The driver that does this *must* be able to deal appropriately
170 * with buffers in "highmemory". This can be accomplished by either calling 170 * with buffers in "highmemory". This can be accomplished by either calling
171 * __bio_kmap_atomic() to get a temporary kernel mapping, or by calling 171 * __bio_kmap_atomic() to get a temporary kernel mapping, or by calling
172 * blk_queue_bounce() to create a buffer in normal memory. 172 * blk_queue_bounce() to create a buffer in normal memory.
173 **/ 173 **/
174 void blk_queue_make_request(struct request_queue *q, make_request_fn *mfn) 174 void blk_queue_make_request(struct request_queue *q, make_request_fn *mfn)
175 { 175 {
176 /* 176 /*
177 * set defaults 177 * set defaults
178 */ 178 */
179 q->nr_requests = BLKDEV_MAX_RQ; 179 q->nr_requests = BLKDEV_MAX_RQ;
180 180
181 q->make_request_fn = mfn; 181 q->make_request_fn = mfn;
182 blk_queue_dma_alignment(q, 511); 182 blk_queue_dma_alignment(q, 511);
183 blk_queue_congestion_threshold(q); 183 blk_queue_congestion_threshold(q);
184 q->nr_batching = BLK_BATCH_REQ; 184 q->nr_batching = BLK_BATCH_REQ;
185 185
186 blk_set_default_limits(&q->limits); 186 blk_set_default_limits(&q->limits);
187 187
188 /* 188 /*
189 * by default assume old behaviour and bounce for any highmem page 189 * by default assume old behaviour and bounce for any highmem page
190 */ 190 */
191 blk_queue_bounce_limit(q, BLK_BOUNCE_HIGH); 191 blk_queue_bounce_limit(q, BLK_BOUNCE_HIGH);
192 } 192 }
193 EXPORT_SYMBOL(blk_queue_make_request); 193 EXPORT_SYMBOL(blk_queue_make_request);
194 194
195 /** 195 /**
196 * blk_queue_bounce_limit - set bounce buffer limit for queue 196 * blk_queue_bounce_limit - set bounce buffer limit for queue
197 * @q: the request queue for the device 197 * @q: the request queue for the device
198 * @dma_mask: the maximum address the device can handle 198 * @max_addr: the maximum address the device can handle
199 * 199 *
200 * Description: 200 * Description:
201 * Different hardware can have different requirements as to what pages 201 * Different hardware can have different requirements as to what pages
202 * it can do I/O directly to. A low level driver can call 202 * it can do I/O directly to. A low level driver can call
203 * blk_queue_bounce_limit to have lower memory pages allocated as bounce 203 * blk_queue_bounce_limit to have lower memory pages allocated as bounce
204 * buffers for doing I/O to pages residing above @dma_mask. 204 * buffers for doing I/O to pages residing above @max_addr.
205 **/ 205 **/
206 void blk_queue_bounce_limit(struct request_queue *q, u64 dma_mask) 206 void blk_queue_bounce_limit(struct request_queue *q, u64 max_addr)
207 { 207 {
208 unsigned long b_pfn = dma_mask >> PAGE_SHIFT; 208 unsigned long b_pfn = max_addr >> PAGE_SHIFT;
209 int dma = 0; 209 int dma = 0;
210 210
211 q->bounce_gfp = GFP_NOIO; 211 q->bounce_gfp = GFP_NOIO;
212 #if BITS_PER_LONG == 64 212 #if BITS_PER_LONG == 64
213 /* 213 /*
214 * Assume anything <= 4GB can be handled by IOMMU. Actually 214 * Assume anything <= 4GB can be handled by IOMMU. Actually
215 * some IOMMUs can handle everything, but I don't know of a 215 * some IOMMUs can handle everything, but I don't know of a
216 * way to test this here. 216 * way to test this here.
217 */ 217 */
218 if (b_pfn < (min_t(u64, 0xffffffffUL, BLK_BOUNCE_HIGH) >> PAGE_SHIFT)) 218 if (b_pfn < (min_t(u64, 0xffffffffUL, BLK_BOUNCE_HIGH) >> PAGE_SHIFT))
219 dma = 1; 219 dma = 1;
220 q->limits.bounce_pfn = max(max_low_pfn, b_pfn); 220 q->limits.bounce_pfn = max(max_low_pfn, b_pfn);
221 #else 221 #else
222 if (b_pfn < blk_max_low_pfn) 222 if (b_pfn < blk_max_low_pfn)
223 dma = 1; 223 dma = 1;
224 q->limits.bounce_pfn = b_pfn; 224 q->limits.bounce_pfn = b_pfn;
225 #endif 225 #endif
226 if (dma) { 226 if (dma) {
227 init_emergency_isa_pool(); 227 init_emergency_isa_pool();
228 q->bounce_gfp = GFP_NOIO | GFP_DMA; 228 q->bounce_gfp = GFP_NOIO | GFP_DMA;
229 q->limits.bounce_pfn = b_pfn; 229 q->limits.bounce_pfn = b_pfn;
230 } 230 }
231 } 231 }
232 EXPORT_SYMBOL(blk_queue_bounce_limit); 232 EXPORT_SYMBOL(blk_queue_bounce_limit);
233 233
234 /** 234 /**
235 * blk_limits_max_hw_sectors - set hard and soft limit of max sectors for request 235 * blk_limits_max_hw_sectors - set hard and soft limit of max sectors for request
236 * @limits: the queue limits 236 * @limits: the queue limits
237 * @max_hw_sectors: max hardware sectors in the usual 512b unit 237 * @max_hw_sectors: max hardware sectors in the usual 512b unit
238 * 238 *
239 * Description: 239 * Description:
240 * Enables a low level driver to set a hard upper limit, 240 * Enables a low level driver to set a hard upper limit,
241 * max_hw_sectors, on the size of requests. max_hw_sectors is set by 241 * max_hw_sectors, on the size of requests. max_hw_sectors is set by
242 * the device driver based upon the combined capabilities of I/O 242 * the device driver based upon the combined capabilities of I/O
243 * controller and storage device. 243 * controller and storage device.
244 * 244 *
245 * max_sectors is a soft limit imposed by the block layer for 245 * max_sectors is a soft limit imposed by the block layer for
246 * filesystem type requests. This value can be overridden on a 246 * filesystem type requests. This value can be overridden on a
247 * per-device basis in /sys/block/<device>/queue/max_sectors_kb. 247 * per-device basis in /sys/block/<device>/queue/max_sectors_kb.
248 * The soft limit can not exceed max_hw_sectors. 248 * The soft limit can not exceed max_hw_sectors.
249 **/ 249 **/
250 void blk_limits_max_hw_sectors(struct queue_limits *limits, unsigned int max_hw_sectors) 250 void blk_limits_max_hw_sectors(struct queue_limits *limits, unsigned int max_hw_sectors)
251 { 251 {
252 if ((max_hw_sectors << 9) < PAGE_CACHE_SIZE) { 252 if ((max_hw_sectors << 9) < PAGE_CACHE_SIZE) {
253 max_hw_sectors = 1 << (PAGE_CACHE_SHIFT - 9); 253 max_hw_sectors = 1 << (PAGE_CACHE_SHIFT - 9);
254 printk(KERN_INFO "%s: set to minimum %d\n", 254 printk(KERN_INFO "%s: set to minimum %d\n",
255 __func__, max_hw_sectors); 255 __func__, max_hw_sectors);
256 } 256 }
257 257
258 limits->max_hw_sectors = max_hw_sectors; 258 limits->max_hw_sectors = max_hw_sectors;
259 limits->max_sectors = min_t(unsigned int, max_hw_sectors, 259 limits->max_sectors = min_t(unsigned int, max_hw_sectors,
260 BLK_DEF_MAX_SECTORS); 260 BLK_DEF_MAX_SECTORS);
261 } 261 }
262 EXPORT_SYMBOL(blk_limits_max_hw_sectors); 262 EXPORT_SYMBOL(blk_limits_max_hw_sectors);
263 263
264 /** 264 /**
265 * blk_queue_max_hw_sectors - set max sectors for a request for this queue 265 * blk_queue_max_hw_sectors - set max sectors for a request for this queue
266 * @q: the request queue for the device 266 * @q: the request queue for the device
267 * @max_hw_sectors: max hardware sectors in the usual 512b unit 267 * @max_hw_sectors: max hardware sectors in the usual 512b unit
268 * 268 *
269 * Description: 269 * Description:
270 * See description for blk_limits_max_hw_sectors(). 270 * See description for blk_limits_max_hw_sectors().
271 **/ 271 **/
272 void blk_queue_max_hw_sectors(struct request_queue *q, unsigned int max_hw_sectors) 272 void blk_queue_max_hw_sectors(struct request_queue *q, unsigned int max_hw_sectors)
273 { 273 {
274 blk_limits_max_hw_sectors(&q->limits, max_hw_sectors); 274 blk_limits_max_hw_sectors(&q->limits, max_hw_sectors);
275 } 275 }
276 EXPORT_SYMBOL(blk_queue_max_hw_sectors); 276 EXPORT_SYMBOL(blk_queue_max_hw_sectors);
277 277
278 /** 278 /**
279 * blk_queue_max_discard_sectors - set max sectors for a single discard 279 * blk_queue_max_discard_sectors - set max sectors for a single discard
280 * @q: the request queue for the device 280 * @q: the request queue for the device
281 * @max_discard_sectors: maximum number of sectors to discard 281 * @max_discard_sectors: maximum number of sectors to discard
282 **/ 282 **/
283 void blk_queue_max_discard_sectors(struct request_queue *q, 283 void blk_queue_max_discard_sectors(struct request_queue *q,
284 unsigned int max_discard_sectors) 284 unsigned int max_discard_sectors)
285 { 285 {
286 q->limits.max_discard_sectors = max_discard_sectors; 286 q->limits.max_discard_sectors = max_discard_sectors;
287 } 287 }
288 EXPORT_SYMBOL(blk_queue_max_discard_sectors); 288 EXPORT_SYMBOL(blk_queue_max_discard_sectors);
289 289
290 /** 290 /**
291 * blk_queue_max_write_same_sectors - set max sectors for a single write same 291 * blk_queue_max_write_same_sectors - set max sectors for a single write same
292 * @q: the request queue for the device 292 * @q: the request queue for the device
293 * @max_write_same_sectors: maximum number of sectors to write per command 293 * @max_write_same_sectors: maximum number of sectors to write per command
294 **/ 294 **/
295 void blk_queue_max_write_same_sectors(struct request_queue *q, 295 void blk_queue_max_write_same_sectors(struct request_queue *q,
296 unsigned int max_write_same_sectors) 296 unsigned int max_write_same_sectors)
297 { 297 {
298 q->limits.max_write_same_sectors = max_write_same_sectors; 298 q->limits.max_write_same_sectors = max_write_same_sectors;
299 } 299 }
300 EXPORT_SYMBOL(blk_queue_max_write_same_sectors); 300 EXPORT_SYMBOL(blk_queue_max_write_same_sectors);
301 301
302 /** 302 /**
303 * blk_queue_max_segments - set max hw segments for a request for this queue 303 * blk_queue_max_segments - set max hw segments for a request for this queue
304 * @q: the request queue for the device 304 * @q: the request queue for the device
305 * @max_segments: max number of segments 305 * @max_segments: max number of segments
306 * 306 *
307 * Description: 307 * Description:
308 * Enables a low level driver to set an upper limit on the number of 308 * Enables a low level driver to set an upper limit on the number of
309 * hw data segments in a request. 309 * hw data segments in a request.
310 **/ 310 **/
311 void blk_queue_max_segments(struct request_queue *q, unsigned short max_segments) 311 void blk_queue_max_segments(struct request_queue *q, unsigned short max_segments)
312 { 312 {
313 if (!max_segments) { 313 if (!max_segments) {
314 max_segments = 1; 314 max_segments = 1;
315 printk(KERN_INFO "%s: set to minimum %d\n", 315 printk(KERN_INFO "%s: set to minimum %d\n",
316 __func__, max_segments); 316 __func__, max_segments);
317 } 317 }
318 318
319 q->limits.max_segments = max_segments; 319 q->limits.max_segments = max_segments;
320 } 320 }
321 EXPORT_SYMBOL(blk_queue_max_segments); 321 EXPORT_SYMBOL(blk_queue_max_segments);
322 322
323 /** 323 /**
324 * blk_queue_max_segment_size - set max segment size for blk_rq_map_sg 324 * blk_queue_max_segment_size - set max segment size for blk_rq_map_sg
325 * @q: the request queue for the device 325 * @q: the request queue for the device
326 * @max_size: max size of segment in bytes 326 * @max_size: max size of segment in bytes
327 * 327 *
328 * Description: 328 * Description:
329 * Enables a low level driver to set an upper limit on the size of a 329 * Enables a low level driver to set an upper limit on the size of a
330 * coalesced segment 330 * coalesced segment
331 **/ 331 **/
332 void blk_queue_max_segment_size(struct request_queue *q, unsigned int max_size) 332 void blk_queue_max_segment_size(struct request_queue *q, unsigned int max_size)
333 { 333 {
334 if (max_size < PAGE_CACHE_SIZE) { 334 if (max_size < PAGE_CACHE_SIZE) {
335 max_size = PAGE_CACHE_SIZE; 335 max_size = PAGE_CACHE_SIZE;
336 printk(KERN_INFO "%s: set to minimum %d\n", 336 printk(KERN_INFO "%s: set to minimum %d\n",
337 __func__, max_size); 337 __func__, max_size);
338 } 338 }
339 339
340 q->limits.max_segment_size = max_size; 340 q->limits.max_segment_size = max_size;
341 } 341 }
342 EXPORT_SYMBOL(blk_queue_max_segment_size); 342 EXPORT_SYMBOL(blk_queue_max_segment_size);
343 343
344 /** 344 /**
345 * blk_queue_logical_block_size - set logical block size for the queue 345 * blk_queue_logical_block_size - set logical block size for the queue
346 * @q: the request queue for the device 346 * @q: the request queue for the device
347 * @size: the logical block size, in bytes 347 * @size: the logical block size, in bytes
348 * 348 *
349 * Description: 349 * Description:
350 * This should be set to the lowest possible block size that the 350 * This should be set to the lowest possible block size that the
351 * storage device can address. The default of 512 covers most 351 * storage device can address. The default of 512 covers most
352 * hardware. 352 * hardware.
353 **/ 353 **/
354 void blk_queue_logical_block_size(struct request_queue *q, unsigned short size) 354 void blk_queue_logical_block_size(struct request_queue *q, unsigned short size)
355 { 355 {
356 q->limits.logical_block_size = size; 356 q->limits.logical_block_size = size;
357 357
358 if (q->limits.physical_block_size < size) 358 if (q->limits.physical_block_size < size)
359 q->limits.physical_block_size = size; 359 q->limits.physical_block_size = size;
360 360
361 if (q->limits.io_min < q->limits.physical_block_size) 361 if (q->limits.io_min < q->limits.physical_block_size)
362 q->limits.io_min = q->limits.physical_block_size; 362 q->limits.io_min = q->limits.physical_block_size;
363 } 363 }
364 EXPORT_SYMBOL(blk_queue_logical_block_size); 364 EXPORT_SYMBOL(blk_queue_logical_block_size);
365 365
366 /** 366 /**
367 * blk_queue_physical_block_size - set physical block size for the queue 367 * blk_queue_physical_block_size - set physical block size for the queue
368 * @q: the request queue for the device 368 * @q: the request queue for the device
369 * @size: the physical block size, in bytes 369 * @size: the physical block size, in bytes
370 * 370 *
371 * Description: 371 * Description:
372 * This should be set to the lowest possible sector size that the 372 * This should be set to the lowest possible sector size that the
373 * hardware can operate on without reverting to read-modify-write 373 * hardware can operate on without reverting to read-modify-write
374 * operations. 374 * operations.
375 */ 375 */
376 void blk_queue_physical_block_size(struct request_queue *q, unsigned int size) 376 void blk_queue_physical_block_size(struct request_queue *q, unsigned int size)
377 { 377 {
378 q->limits.physical_block_size = size; 378 q->limits.physical_block_size = size;
379 379
380 if (q->limits.physical_block_size < q->limits.logical_block_size) 380 if (q->limits.physical_block_size < q->limits.logical_block_size)
381 q->limits.physical_block_size = q->limits.logical_block_size; 381 q->limits.physical_block_size = q->limits.logical_block_size;
382 382
383 if (q->limits.io_min < q->limits.physical_block_size) 383 if (q->limits.io_min < q->limits.physical_block_size)
384 q->limits.io_min = q->limits.physical_block_size; 384 q->limits.io_min = q->limits.physical_block_size;
385 } 385 }
386 EXPORT_SYMBOL(blk_queue_physical_block_size); 386 EXPORT_SYMBOL(blk_queue_physical_block_size);
387 387
388 /** 388 /**
389 * blk_queue_alignment_offset - set physical block alignment offset 389 * blk_queue_alignment_offset - set physical block alignment offset
390 * @q: the request queue for the device 390 * @q: the request queue for the device
391 * @offset: alignment offset in bytes 391 * @offset: alignment offset in bytes
392 * 392 *
393 * Description: 393 * Description:
394 * Some devices are naturally misaligned to compensate for things like 394 * Some devices are naturally misaligned to compensate for things like
395 * the legacy DOS partition table 63-sector offset. Low-level drivers 395 * the legacy DOS partition table 63-sector offset. Low-level drivers
396 * should call this function for devices whose first sector is not 396 * should call this function for devices whose first sector is not
397 * naturally aligned. 397 * naturally aligned.
398 */ 398 */
399 void blk_queue_alignment_offset(struct request_queue *q, unsigned int offset) 399 void blk_queue_alignment_offset(struct request_queue *q, unsigned int offset)
400 { 400 {
401 q->limits.alignment_offset = 401 q->limits.alignment_offset =
402 offset & (q->limits.physical_block_size - 1); 402 offset & (q->limits.physical_block_size - 1);
403 q->limits.misaligned = 0; 403 q->limits.misaligned = 0;
404 } 404 }
405 EXPORT_SYMBOL(blk_queue_alignment_offset); 405 EXPORT_SYMBOL(blk_queue_alignment_offset);
406 406
407 /** 407 /**
408 * blk_limits_io_min - set minimum request size for a device 408 * blk_limits_io_min - set minimum request size for a device
409 * @limits: the queue limits 409 * @limits: the queue limits
410 * @min: smallest I/O size in bytes 410 * @min: smallest I/O size in bytes
411 * 411 *
412 * Description: 412 * Description:
413 * Some devices have an internal block size bigger than the reported 413 * Some devices have an internal block size bigger than the reported
414 * hardware sector size. This function can be used to signal the 414 * hardware sector size. This function can be used to signal the
415 * smallest I/O the device can perform without incurring a performance 415 * smallest I/O the device can perform without incurring a performance
416 * penalty. 416 * penalty.
417 */ 417 */
418 void blk_limits_io_min(struct queue_limits *limits, unsigned int min) 418 void blk_limits_io_min(struct queue_limits *limits, unsigned int min)
419 { 419 {
420 limits->io_min = min; 420 limits->io_min = min;
421 421
422 if (limits->io_min < limits->logical_block_size) 422 if (limits->io_min < limits->logical_block_size)
423 limits->io_min = limits->logical_block_size; 423 limits->io_min = limits->logical_block_size;
424 424
425 if (limits->io_min < limits->physical_block_size) 425 if (limits->io_min < limits->physical_block_size)
426 limits->io_min = limits->physical_block_size; 426 limits->io_min = limits->physical_block_size;
427 } 427 }
428 EXPORT_SYMBOL(blk_limits_io_min); 428 EXPORT_SYMBOL(blk_limits_io_min);
429 429
430 /** 430 /**
431 * blk_queue_io_min - set minimum request size for the queue 431 * blk_queue_io_min - set minimum request size for the queue
432 * @q: the request queue for the device 432 * @q: the request queue for the device
433 * @min: smallest I/O size in bytes 433 * @min: smallest I/O size in bytes
434 * 434 *
435 * Description: 435 * Description:
436 * Storage devices may report a granularity or preferred minimum I/O 436 * Storage devices may report a granularity or preferred minimum I/O
437 * size which is the smallest request the device can perform without 437 * size which is the smallest request the device can perform without
438 * incurring a performance penalty. For disk drives this is often the 438 * incurring a performance penalty. For disk drives this is often the
439 * physical block size. For RAID arrays it is often the stripe chunk 439 * physical block size. For RAID arrays it is often the stripe chunk
440 * size. A properly aligned multiple of minimum_io_size is the 440 * size. A properly aligned multiple of minimum_io_size is the
441 * preferred request size for workloads where a high number of I/O 441 * preferred request size for workloads where a high number of I/O
442 * operations is desired. 442 * operations is desired.
443 */ 443 */
444 void blk_queue_io_min(struct request_queue *q, unsigned int min) 444 void blk_queue_io_min(struct request_queue *q, unsigned int min)
445 { 445 {
446 blk_limits_io_min(&q->limits, min); 446 blk_limits_io_min(&q->limits, min);
447 } 447 }
448 EXPORT_SYMBOL(blk_queue_io_min); 448 EXPORT_SYMBOL(blk_queue_io_min);
449 449
450 /** 450 /**
451 * blk_limits_io_opt - set optimal request size for a device 451 * blk_limits_io_opt - set optimal request size for a device
452 * @limits: the queue limits 452 * @limits: the queue limits
453 * @opt: smallest I/O size in bytes 453 * @opt: smallest I/O size in bytes
454 * 454 *
455 * Description: 455 * Description:
456 * Storage devices may report an optimal I/O size, which is the 456 * Storage devices may report an optimal I/O size, which is the
457 * device's preferred unit for sustained I/O. This is rarely reported 457 * device's preferred unit for sustained I/O. This is rarely reported
458 * for disk drives. For RAID arrays it is usually the stripe width or 458 * for disk drives. For RAID arrays it is usually the stripe width or
459 * the internal track size. A properly aligned multiple of 459 * the internal track size. A properly aligned multiple of
460 * optimal_io_size is the preferred request size for workloads where 460 * optimal_io_size is the preferred request size for workloads where
461 * sustained throughput is desired. 461 * sustained throughput is desired.
462 */ 462 */
463 void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt) 463 void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt)
464 { 464 {
465 limits->io_opt = opt; 465 limits->io_opt = opt;
466 } 466 }
467 EXPORT_SYMBOL(blk_limits_io_opt); 467 EXPORT_SYMBOL(blk_limits_io_opt);
468 468
469 /** 469 /**
470 * blk_queue_io_opt - set optimal request size for the queue 470 * blk_queue_io_opt - set optimal request size for the queue
471 * @q: the request queue for the device 471 * @q: the request queue for the device
472 * @opt: optimal request size in bytes 472 * @opt: optimal request size in bytes
473 * 473 *
474 * Description: 474 * Description:
475 * Storage devices may report an optimal I/O size, which is the 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 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 477 * for disk drives. For RAID arrays it is usually the stripe width or
478 * the internal track size. A properly aligned multiple of 478 * the internal track size. A properly aligned multiple of
479 * optimal_io_size is the preferred request size for workloads where 479 * optimal_io_size is the preferred request size for workloads where
480 * sustained throughput is desired. 480 * sustained throughput is desired.
481 */ 481 */
482 void blk_queue_io_opt(struct request_queue *q, unsigned int opt) 482 void blk_queue_io_opt(struct request_queue *q, unsigned int opt)
483 { 483 {
484 blk_limits_io_opt(&q->limits, opt); 484 blk_limits_io_opt(&q->limits, opt);
485 } 485 }
486 EXPORT_SYMBOL(blk_queue_io_opt); 486 EXPORT_SYMBOL(blk_queue_io_opt);
487 487
488 /** 488 /**
489 * blk_queue_stack_limits - inherit underlying queue limits for stacked drivers 489 * blk_queue_stack_limits - inherit underlying queue limits for stacked drivers
490 * @t: the stacking driver (top) 490 * @t: the stacking driver (top)
491 * @b: the underlying device (bottom) 491 * @b: the underlying device (bottom)
492 **/ 492 **/
493 void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b) 493 void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b)
494 { 494 {
495 blk_stack_limits(&t->limits, &b->limits, 0); 495 blk_stack_limits(&t->limits, &b->limits, 0);
496 } 496 }
497 EXPORT_SYMBOL(blk_queue_stack_limits); 497 EXPORT_SYMBOL(blk_queue_stack_limits);
498 498
499 /** 499 /**
500 * blk_stack_limits - adjust queue_limits for stacked devices 500 * blk_stack_limits - adjust queue_limits for stacked devices
501 * @t: the stacking driver limits (top device) 501 * @t: the stacking driver limits (top device)
502 * @b: the underlying queue limits (bottom, component device) 502 * @b: the underlying queue limits (bottom, component device)
503 * @start: first data sector within component device 503 * @start: first data sector within component device
504 * 504 *
505 * Description: 505 * Description:
506 * This function is used by stacking drivers like MD and DM to ensure 506 * This function is used by stacking drivers like MD and DM to ensure
507 * that all component devices have compatible block sizes and 507 * that all component devices have compatible block sizes and
508 * alignments. The stacking driver must provide a queue_limits 508 * alignments. The stacking driver must provide a queue_limits
509 * struct (top) and then iteratively call the stacking function for 509 * struct (top) and then iteratively call the stacking function for
510 * all component (bottom) devices. The stacking function will 510 * all component (bottom) devices. The stacking function will
511 * attempt to combine the values and ensure proper alignment. 511 * attempt to combine the values and ensure proper alignment.
512 * 512 *
513 * Returns 0 if the top and bottom queue_limits are compatible. The 513 * Returns 0 if the top and bottom queue_limits are compatible. The
514 * top device's block sizes and alignment offsets may be adjusted to 514 * top device's block sizes and alignment offsets may be adjusted to
515 * ensure alignment with the bottom device. If no compatible sizes 515 * ensure alignment with the bottom device. If no compatible sizes
516 * and alignments exist, -1 is returned and the resulting top 516 * and alignments exist, -1 is returned and the resulting top
517 * queue_limits will have the misaligned flag set to indicate that 517 * queue_limits will have the misaligned flag set to indicate that
518 * the alignment_offset is undefined. 518 * the alignment_offset is undefined.
519 */ 519 */
520 int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, 520 int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
521 sector_t start) 521 sector_t start)
522 { 522 {
523 unsigned int top, bottom, alignment, ret = 0; 523 unsigned int top, bottom, alignment, ret = 0;
524 524
525 t->max_sectors = min_not_zero(t->max_sectors, b->max_sectors); 525 t->max_sectors = min_not_zero(t->max_sectors, b->max_sectors);
526 t->max_hw_sectors = min_not_zero(t->max_hw_sectors, b->max_hw_sectors); 526 t->max_hw_sectors = min_not_zero(t->max_hw_sectors, b->max_hw_sectors);
527 t->max_write_same_sectors = min(t->max_write_same_sectors, 527 t->max_write_same_sectors = min(t->max_write_same_sectors,
528 b->max_write_same_sectors); 528 b->max_write_same_sectors);
529 t->bounce_pfn = min_not_zero(t->bounce_pfn, b->bounce_pfn); 529 t->bounce_pfn = min_not_zero(t->bounce_pfn, b->bounce_pfn);
530 530
531 t->seg_boundary_mask = min_not_zero(t->seg_boundary_mask, 531 t->seg_boundary_mask = min_not_zero(t->seg_boundary_mask,
532 b->seg_boundary_mask); 532 b->seg_boundary_mask);
533 533
534 t->max_segments = min_not_zero(t->max_segments, b->max_segments); 534 t->max_segments = min_not_zero(t->max_segments, b->max_segments);
535 t->max_integrity_segments = min_not_zero(t->max_integrity_segments, 535 t->max_integrity_segments = min_not_zero(t->max_integrity_segments,
536 b->max_integrity_segments); 536 b->max_integrity_segments);
537 537
538 t->max_segment_size = min_not_zero(t->max_segment_size, 538 t->max_segment_size = min_not_zero(t->max_segment_size,
539 b->max_segment_size); 539 b->max_segment_size);
540 540
541 t->misaligned |= b->misaligned; 541 t->misaligned |= b->misaligned;
542 542
543 alignment = queue_limit_alignment_offset(b, start); 543 alignment = queue_limit_alignment_offset(b, start);
544 544
545 /* Bottom device has different alignment. Check that it is 545 /* Bottom device has different alignment. Check that it is
546 * compatible with the current top alignment. 546 * compatible with the current top alignment.
547 */ 547 */
548 if (t->alignment_offset != alignment) { 548 if (t->alignment_offset != alignment) {
549 549
550 top = max(t->physical_block_size, t->io_min) 550 top = max(t->physical_block_size, t->io_min)
551 + t->alignment_offset; 551 + t->alignment_offset;
552 bottom = max(b->physical_block_size, b->io_min) + alignment; 552 bottom = max(b->physical_block_size, b->io_min) + alignment;
553 553
554 /* Verify that top and bottom intervals line up */ 554 /* Verify that top and bottom intervals line up */
555 if (max(top, bottom) & (min(top, bottom) - 1)) { 555 if (max(top, bottom) & (min(top, bottom) - 1)) {
556 t->misaligned = 1; 556 t->misaligned = 1;
557 ret = -1; 557 ret = -1;
558 } 558 }
559 } 559 }
560 560
561 t->logical_block_size = max(t->logical_block_size, 561 t->logical_block_size = max(t->logical_block_size,
562 b->logical_block_size); 562 b->logical_block_size);
563 563
564 t->physical_block_size = max(t->physical_block_size, 564 t->physical_block_size = max(t->physical_block_size,
565 b->physical_block_size); 565 b->physical_block_size);
566 566
567 t->io_min = max(t->io_min, b->io_min); 567 t->io_min = max(t->io_min, b->io_min);
568 t->io_opt = lcm(t->io_opt, b->io_opt); 568 t->io_opt = lcm(t->io_opt, b->io_opt);
569 569
570 t->cluster &= b->cluster; 570 t->cluster &= b->cluster;
571 t->discard_zeroes_data &= b->discard_zeroes_data; 571 t->discard_zeroes_data &= b->discard_zeroes_data;
572 572
573 /* Physical block size a multiple of the logical block size? */ 573 /* Physical block size a multiple of the logical block size? */
574 if (t->physical_block_size & (t->logical_block_size - 1)) { 574 if (t->physical_block_size & (t->logical_block_size - 1)) {
575 t->physical_block_size = t->logical_block_size; 575 t->physical_block_size = t->logical_block_size;
576 t->misaligned = 1; 576 t->misaligned = 1;
577 ret = -1; 577 ret = -1;
578 } 578 }
579 579
580 /* Minimum I/O a multiple of the physical block size? */ 580 /* Minimum I/O a multiple of the physical block size? */
581 if (t->io_min & (t->physical_block_size - 1)) { 581 if (t->io_min & (t->physical_block_size - 1)) {
582 t->io_min = t->physical_block_size; 582 t->io_min = t->physical_block_size;
583 t->misaligned = 1; 583 t->misaligned = 1;
584 ret = -1; 584 ret = -1;
585 } 585 }
586 586
587 /* Optimal I/O a multiple of the physical block size? */ 587 /* Optimal I/O a multiple of the physical block size? */
588 if (t->io_opt & (t->physical_block_size - 1)) { 588 if (t->io_opt & (t->physical_block_size - 1)) {
589 t->io_opt = 0; 589 t->io_opt = 0;
590 t->misaligned = 1; 590 t->misaligned = 1;
591 ret = -1; 591 ret = -1;
592 } 592 }
593 593
594 /* Find lowest common alignment_offset */ 594 /* Find lowest common alignment_offset */
595 t->alignment_offset = lcm(t->alignment_offset, alignment) 595 t->alignment_offset = lcm(t->alignment_offset, alignment)
596 & (max(t->physical_block_size, t->io_min) - 1); 596 & (max(t->physical_block_size, t->io_min) - 1);
597 597
598 /* Verify that new alignment_offset is on a logical block boundary */ 598 /* Verify that new alignment_offset is on a logical block boundary */
599 if (t->alignment_offset & (t->logical_block_size - 1)) { 599 if (t->alignment_offset & (t->logical_block_size - 1)) {
600 t->misaligned = 1; 600 t->misaligned = 1;
601 ret = -1; 601 ret = -1;
602 } 602 }
603 603
604 /* Discard alignment and granularity */ 604 /* Discard alignment and granularity */
605 if (b->discard_granularity) { 605 if (b->discard_granularity) {
606 alignment = queue_limit_discard_alignment(b, start); 606 alignment = queue_limit_discard_alignment(b, start);
607 607
608 if (t->discard_granularity != 0 && 608 if (t->discard_granularity != 0 &&
609 t->discard_alignment != alignment) { 609 t->discard_alignment != alignment) {
610 top = t->discard_granularity + t->discard_alignment; 610 top = t->discard_granularity + t->discard_alignment;
611 bottom = b->discard_granularity + alignment; 611 bottom = b->discard_granularity + alignment;
612 612
613 /* Verify that top and bottom intervals line up */ 613 /* Verify that top and bottom intervals line up */
614 if ((max(top, bottom) % min(top, bottom)) != 0) 614 if ((max(top, bottom) % min(top, bottom)) != 0)
615 t->discard_misaligned = 1; 615 t->discard_misaligned = 1;
616 } 616 }
617 617
618 t->max_discard_sectors = min_not_zero(t->max_discard_sectors, 618 t->max_discard_sectors = min_not_zero(t->max_discard_sectors,
619 b->max_discard_sectors); 619 b->max_discard_sectors);
620 t->discard_granularity = max(t->discard_granularity, 620 t->discard_granularity = max(t->discard_granularity,
621 b->discard_granularity); 621 b->discard_granularity);
622 t->discard_alignment = lcm(t->discard_alignment, alignment) % 622 t->discard_alignment = lcm(t->discard_alignment, alignment) %
623 t->discard_granularity; 623 t->discard_granularity;
624 } 624 }
625 625
626 return ret; 626 return ret;
627 } 627 }
628 EXPORT_SYMBOL(blk_stack_limits); 628 EXPORT_SYMBOL(blk_stack_limits);
629 629
630 /** 630 /**
631 * bdev_stack_limits - adjust queue limits for stacked drivers 631 * bdev_stack_limits - adjust queue limits for stacked drivers
632 * @t: the stacking driver limits (top device) 632 * @t: the stacking driver limits (top device)
633 * @bdev: the component block_device (bottom) 633 * @bdev: the component block_device (bottom)
634 * @start: first data sector within component device 634 * @start: first data sector within component device
635 * 635 *
636 * Description: 636 * Description:
637 * Merges queue limits for a top device and a block_device. Returns 637 * Merges queue limits for a top device and a block_device. Returns
638 * 0 if alignment didn't change. Returns -1 if adding the bottom 638 * 0 if alignment didn't change. Returns -1 if adding the bottom
639 * device caused misalignment. 639 * device caused misalignment.
640 */ 640 */
641 int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev, 641 int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev,
642 sector_t start) 642 sector_t start)
643 { 643 {
644 struct request_queue *bq = bdev_get_queue(bdev); 644 struct request_queue *bq = bdev_get_queue(bdev);
645 645
646 start += get_start_sect(bdev); 646 start += get_start_sect(bdev);
647 647
648 return blk_stack_limits(t, &bq->limits, start); 648 return blk_stack_limits(t, &bq->limits, start);
649 } 649 }
650 EXPORT_SYMBOL(bdev_stack_limits); 650 EXPORT_SYMBOL(bdev_stack_limits);
651 651
652 /** 652 /**
653 * disk_stack_limits - adjust queue limits for stacked drivers 653 * disk_stack_limits - adjust queue limits for stacked drivers
654 * @disk: MD/DM gendisk (top) 654 * @disk: MD/DM gendisk (top)
655 * @bdev: the underlying block device (bottom) 655 * @bdev: the underlying block device (bottom)
656 * @offset: offset to beginning of data within component device 656 * @offset: offset to beginning of data within component device
657 * 657 *
658 * Description: 658 * Description:
659 * Merges the limits for a top level gendisk and a bottom level 659 * Merges the limits for a top level gendisk and a bottom level
660 * block_device. 660 * block_device.
661 */ 661 */
662 void disk_stack_limits(struct gendisk *disk, struct block_device *bdev, 662 void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
663 sector_t offset) 663 sector_t offset)
664 { 664 {
665 struct request_queue *t = disk->queue; 665 struct request_queue *t = disk->queue;
666 666
667 if (bdev_stack_limits(&t->limits, bdev, offset >> 9) < 0) { 667 if (bdev_stack_limits(&t->limits, bdev, offset >> 9) < 0) {
668 char top[BDEVNAME_SIZE], bottom[BDEVNAME_SIZE]; 668 char top[BDEVNAME_SIZE], bottom[BDEVNAME_SIZE];
669 669
670 disk_name(disk, 0, top); 670 disk_name(disk, 0, top);
671 bdevname(bdev, bottom); 671 bdevname(bdev, bottom);
672 672
673 printk(KERN_NOTICE "%s: Warning: Device %s is misaligned\n", 673 printk(KERN_NOTICE "%s: Warning: Device %s is misaligned\n",
674 top, bottom); 674 top, bottom);
675 } 675 }
676 } 676 }
677 EXPORT_SYMBOL(disk_stack_limits); 677 EXPORT_SYMBOL(disk_stack_limits);
678 678
679 /** 679 /**
680 * blk_queue_dma_pad - set pad mask 680 * blk_queue_dma_pad - set pad mask
681 * @q: the request queue for the device 681 * @q: the request queue for the device
682 * @mask: pad mask 682 * @mask: pad mask
683 * 683 *
684 * Set dma pad mask. 684 * Set dma pad mask.
685 * 685 *
686 * Appending pad buffer to a request modifies the last entry of a 686 * Appending pad buffer to a request modifies the last entry of a
687 * scatter list such that it includes the pad buffer. 687 * scatter list such that it includes the pad buffer.
688 **/ 688 **/
689 void blk_queue_dma_pad(struct request_queue *q, unsigned int mask) 689 void blk_queue_dma_pad(struct request_queue *q, unsigned int mask)
690 { 690 {
691 q->dma_pad_mask = mask; 691 q->dma_pad_mask = mask;
692 } 692 }
693 EXPORT_SYMBOL(blk_queue_dma_pad); 693 EXPORT_SYMBOL(blk_queue_dma_pad);
694 694
695 /** 695 /**
696 * blk_queue_update_dma_pad - update pad mask 696 * blk_queue_update_dma_pad - update pad mask
697 * @q: the request queue for the device 697 * @q: the request queue for the device
698 * @mask: pad mask 698 * @mask: pad mask
699 * 699 *
700 * Update dma pad mask. 700 * Update dma pad mask.
701 * 701 *
702 * Appending pad buffer to a request modifies the last entry of a 702 * Appending pad buffer to a request modifies the last entry of a
703 * scatter list such that it includes the pad buffer. 703 * scatter list such that it includes the pad buffer.
704 **/ 704 **/
705 void blk_queue_update_dma_pad(struct request_queue *q, unsigned int mask) 705 void blk_queue_update_dma_pad(struct request_queue *q, unsigned int mask)
706 { 706 {
707 if (mask > q->dma_pad_mask) 707 if (mask > q->dma_pad_mask)
708 q->dma_pad_mask = mask; 708 q->dma_pad_mask = mask;
709 } 709 }
710 EXPORT_SYMBOL(blk_queue_update_dma_pad); 710 EXPORT_SYMBOL(blk_queue_update_dma_pad);
711 711
712 /** 712 /**
713 * blk_queue_dma_drain - Set up a drain buffer for excess dma. 713 * blk_queue_dma_drain - Set up a drain buffer for excess dma.
714 * @q: the request queue for the device 714 * @q: the request queue for the device
715 * @dma_drain_needed: fn which returns non-zero if drain is necessary 715 * @dma_drain_needed: fn which returns non-zero if drain is necessary
716 * @buf: physically contiguous buffer 716 * @buf: physically contiguous buffer
717 * @size: size of the buffer in bytes 717 * @size: size of the buffer in bytes
718 * 718 *
719 * Some devices have excess DMA problems and can't simply discard (or 719 * Some devices have excess DMA problems and can't simply discard (or
720 * zero fill) the unwanted piece of the transfer. They have to have a 720 * zero fill) the unwanted piece of the transfer. They have to have a
721 * real area of memory to transfer it into. The use case for this is 721 * real area of memory to transfer it into. The use case for this is
722 * ATAPI devices in DMA mode. If the packet command causes a transfer 722 * ATAPI devices in DMA mode. If the packet command causes a transfer
723 * bigger than the transfer size some HBAs will lock up if there 723 * bigger than the transfer size some HBAs will lock up if there
724 * aren't DMA elements to contain the excess transfer. What this API 724 * aren't DMA elements to contain the excess transfer. What this API
725 * does is adjust the queue so that the buf is always appended 725 * does is adjust the queue so that the buf is always appended
726 * silently to the scatterlist. 726 * silently to the scatterlist.
727 * 727 *
728 * Note: This routine adjusts max_hw_segments to make room for appending 728 * Note: This routine adjusts max_hw_segments to make room for appending
729 * the drain buffer. If you call blk_queue_max_segments() after calling 729 * the drain buffer. If you call blk_queue_max_segments() after calling
730 * this routine, you must set the limit to one fewer than your device 730 * this routine, you must set the limit to one fewer than your device
731 * can support otherwise there won't be room for the drain buffer. 731 * can support otherwise there won't be room for the drain buffer.
732 */ 732 */
733 int blk_queue_dma_drain(struct request_queue *q, 733 int blk_queue_dma_drain(struct request_queue *q,
734 dma_drain_needed_fn *dma_drain_needed, 734 dma_drain_needed_fn *dma_drain_needed,
735 void *buf, unsigned int size) 735 void *buf, unsigned int size)
736 { 736 {
737 if (queue_max_segments(q) < 2) 737 if (queue_max_segments(q) < 2)
738 return -EINVAL; 738 return -EINVAL;
739 /* make room for appending the drain */ 739 /* make room for appending the drain */
740 blk_queue_max_segments(q, queue_max_segments(q) - 1); 740 blk_queue_max_segments(q, queue_max_segments(q) - 1);
741 q->dma_drain_needed = dma_drain_needed; 741 q->dma_drain_needed = dma_drain_needed;
742 q->dma_drain_buffer = buf; 742 q->dma_drain_buffer = buf;
743 q->dma_drain_size = size; 743 q->dma_drain_size = size;
744 744
745 return 0; 745 return 0;
746 } 746 }
747 EXPORT_SYMBOL_GPL(blk_queue_dma_drain); 747 EXPORT_SYMBOL_GPL(blk_queue_dma_drain);
748 748
749 /** 749 /**
750 * blk_queue_segment_boundary - set boundary rules for segment merging 750 * blk_queue_segment_boundary - set boundary rules for segment merging
751 * @q: the request queue for the device 751 * @q: the request queue for the device
752 * @mask: the memory boundary mask 752 * @mask: the memory boundary mask
753 **/ 753 **/
754 void blk_queue_segment_boundary(struct request_queue *q, unsigned long mask) 754 void blk_queue_segment_boundary(struct request_queue *q, unsigned long mask)
755 { 755 {
756 if (mask < PAGE_CACHE_SIZE - 1) { 756 if (mask < PAGE_CACHE_SIZE - 1) {
757 mask = PAGE_CACHE_SIZE - 1; 757 mask = PAGE_CACHE_SIZE - 1;
758 printk(KERN_INFO "%s: set to minimum %lx\n", 758 printk(KERN_INFO "%s: set to minimum %lx\n",
759 __func__, mask); 759 __func__, mask);
760 } 760 }
761 761
762 q->limits.seg_boundary_mask = mask; 762 q->limits.seg_boundary_mask = mask;
763 } 763 }
764 EXPORT_SYMBOL(blk_queue_segment_boundary); 764 EXPORT_SYMBOL(blk_queue_segment_boundary);
765 765
766 /** 766 /**
767 * blk_queue_dma_alignment - set dma length and memory alignment 767 * blk_queue_dma_alignment - set dma length and memory alignment
768 * @q: the request queue for the device 768 * @q: the request queue for the device
769 * @mask: alignment mask 769 * @mask: alignment mask
770 * 770 *
771 * description: 771 * description:
772 * set required memory and length alignment for direct dma transactions. 772 * set required memory and length alignment for direct dma transactions.
773 * this is used when building direct io requests for the queue. 773 * this is used when building direct io requests for the queue.
774 * 774 *
775 **/ 775 **/
776 void blk_queue_dma_alignment(struct request_queue *q, int mask) 776 void blk_queue_dma_alignment(struct request_queue *q, int mask)
777 { 777 {
778 q->dma_alignment = mask; 778 q->dma_alignment = mask;
779 } 779 }
780 EXPORT_SYMBOL(blk_queue_dma_alignment); 780 EXPORT_SYMBOL(blk_queue_dma_alignment);
781 781
782 /** 782 /**
783 * blk_queue_update_dma_alignment - update dma length and memory alignment 783 * blk_queue_update_dma_alignment - update dma length and memory alignment
784 * @q: the request queue for the device 784 * @q: the request queue for the device
785 * @mask: alignment mask 785 * @mask: alignment mask
786 * 786 *
787 * description: 787 * description:
788 * update required memory and length alignment for direct dma transactions. 788 * update required memory and length alignment for direct dma transactions.
789 * If the requested alignment is larger than the current alignment, then 789 * If the requested alignment is larger than the current alignment, then
790 * the current queue alignment is updated to the new value, otherwise it 790 * the current queue alignment is updated to the new value, otherwise it
791 * is left alone. The design of this is to allow multiple objects 791 * is left alone. The design of this is to allow multiple objects
792 * (driver, device, transport etc) to set their respective 792 * (driver, device, transport etc) to set their respective
793 * alignments without having them interfere. 793 * alignments without having them interfere.
794 * 794 *
795 **/ 795 **/
796 void blk_queue_update_dma_alignment(struct request_queue *q, int mask) 796 void blk_queue_update_dma_alignment(struct request_queue *q, int mask)
797 { 797 {
798 BUG_ON(mask > PAGE_SIZE); 798 BUG_ON(mask > PAGE_SIZE);
799 799
800 if (mask > q->dma_alignment) 800 if (mask > q->dma_alignment)
801 q->dma_alignment = mask; 801 q->dma_alignment = mask;
802 } 802 }
803 EXPORT_SYMBOL(blk_queue_update_dma_alignment); 803 EXPORT_SYMBOL(blk_queue_update_dma_alignment);
804 804
805 /** 805 /**
806 * blk_queue_flush - configure queue's cache flush capability 806 * blk_queue_flush - configure queue's cache flush capability
807 * @q: the request queue for the device 807 * @q: the request queue for the device
808 * @flush: 0, REQ_FLUSH or REQ_FLUSH | REQ_FUA 808 * @flush: 0, REQ_FLUSH or REQ_FLUSH | REQ_FUA
809 * 809 *
810 * Tell block layer cache flush capability of @q. If it supports 810 * Tell block layer cache flush capability of @q. If it supports
811 * flushing, REQ_FLUSH should be set. If it supports bypassing 811 * flushing, REQ_FLUSH should be set. If it supports bypassing
812 * write cache for individual writes, REQ_FUA should be set. 812 * write cache for individual writes, REQ_FUA should be set.
813 */ 813 */
814 void blk_queue_flush(struct request_queue *q, unsigned int flush) 814 void blk_queue_flush(struct request_queue *q, unsigned int flush)
815 { 815 {
816 WARN_ON_ONCE(flush & ~(REQ_FLUSH | REQ_FUA)); 816 WARN_ON_ONCE(flush & ~(REQ_FLUSH | REQ_FUA));
817 817
818 if (WARN_ON_ONCE(!(flush & REQ_FLUSH) && (flush & REQ_FUA))) 818 if (WARN_ON_ONCE(!(flush & REQ_FLUSH) && (flush & REQ_FUA)))
819 flush &= ~REQ_FUA; 819 flush &= ~REQ_FUA;
820 820
821 q->flush_flags = flush & (REQ_FLUSH | REQ_FUA); 821 q->flush_flags = flush & (REQ_FLUSH | REQ_FUA);
822 } 822 }
823 EXPORT_SYMBOL_GPL(blk_queue_flush); 823 EXPORT_SYMBOL_GPL(blk_queue_flush);
824 824
825 void blk_queue_flush_queueable(struct request_queue *q, bool queueable) 825 void blk_queue_flush_queueable(struct request_queue *q, bool queueable)
826 { 826 {
827 q->flush_not_queueable = !queueable; 827 q->flush_not_queueable = !queueable;
828 } 828 }
829 EXPORT_SYMBOL_GPL(blk_queue_flush_queueable); 829 EXPORT_SYMBOL_GPL(blk_queue_flush_queueable);
830 830
831 static int __init blk_settings_init(void) 831 static int __init blk_settings_init(void)
832 { 832 {
833 blk_max_low_pfn = max_low_pfn - 1; 833 blk_max_low_pfn = max_low_pfn - 1;
834 blk_max_pfn = max_pfn - 1; 834 blk_max_pfn = max_pfn - 1;
835 return 0; 835 return 0;
836 } 836 }
837 subsys_initcall(blk_settings_init); 837 subsys_initcall(blk_settings_init);
838 838