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Commit | Line | Data |
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1da177e4 | 1 | /* |
98ac2162 | 2 | * linux/drivers/mmc/queue.c |
1da177e4 LT |
3 | * |
4 | * Copyright (C) 2003 Russell King, All Rights Reserved. | |
98ac2162 | 5 | * Copyright 2006-2007 Pierre Ossman |
1da177e4 LT |
6 | * |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | * | |
11 | */ | |
12 | #include <linux/module.h> | |
13 | #include <linux/blkdev.h> | |
87598a2b | 14 | #include <linux/kthread.h> |
1da177e4 LT |
15 | |
16 | #include <linux/mmc/card.h> | |
17 | #include <linux/mmc/host.h> | |
98ac2162 | 18 | #include "queue.h" |
1da177e4 | 19 | |
98ccf149 PO |
20 | #define MMC_QUEUE_BOUNCESZ 65536 |
21 | ||
87598a2b | 22 | #define MMC_QUEUE_SUSPENDED (1 << 0) |
1da177e4 LT |
23 | |
24 | /* | |
9c9f2d63 | 25 | * Prepare a MMC request. This just filters out odd stuff. |
1da177e4 LT |
26 | */ |
27 | static int mmc_prep_request(struct request_queue *q, struct request *req) | |
28 | { | |
9c9f2d63 PO |
29 | /* |
30 | * We only like normal block requests. | |
31 | */ | |
32 | if (!blk_fs_request(req) && !blk_pc_request(req)) { | |
1da177e4 | 33 | blk_dump_rq_flags(req, "MMC bad request"); |
9c9f2d63 | 34 | return BLKPREP_KILL; |
1da177e4 LT |
35 | } |
36 | ||
9c9f2d63 | 37 | req->cmd_flags |= REQ_DONTPREP; |
1da177e4 | 38 | |
9c9f2d63 | 39 | return BLKPREP_OK; |
1da177e4 LT |
40 | } |
41 | ||
42 | static int mmc_queue_thread(void *d) | |
43 | { | |
44 | struct mmc_queue *mq = d; | |
45 | struct request_queue *q = mq->queue; | |
1da177e4 LT |
46 | |
47 | /* | |
48 | * Set iothread to ensure that we aren't put to sleep by | |
49 | * the process freezing. We handle suspension ourselves. | |
50 | */ | |
51 | current->flags |= PF_MEMALLOC|PF_NOFREEZE; | |
52 | ||
1da177e4 | 53 | down(&mq->thread_sem); |
1da177e4 LT |
54 | do { |
55 | struct request *req = NULL; | |
56 | ||
57 | spin_lock_irq(q->queue_lock); | |
58 | set_current_state(TASK_INTERRUPTIBLE); | |
59 | if (!blk_queue_plugged(q)) | |
c723e08a JY |
60 | req = elv_next_request(q); |
61 | mq->req = req; | |
1da177e4 LT |
62 | spin_unlock_irq(q->queue_lock); |
63 | ||
64 | if (!req) { | |
7b30d281 VW |
65 | if (kthread_should_stop()) { |
66 | set_current_state(TASK_RUNNING); | |
1da177e4 | 67 | break; |
7b30d281 | 68 | } |
1da177e4 LT |
69 | up(&mq->thread_sem); |
70 | schedule(); | |
71 | down(&mq->thread_sem); | |
72 | continue; | |
73 | } | |
74 | set_current_state(TASK_RUNNING); | |
75 | ||
76 | mq->issue_fn(mq, req); | |
77 | } while (1); | |
1da177e4 LT |
78 | up(&mq->thread_sem); |
79 | ||
1da177e4 LT |
80 | return 0; |
81 | } | |
82 | ||
83 | /* | |
84 | * Generic MMC request handler. This is called for any queue on a | |
85 | * particular host. When the host is not busy, we look for a request | |
86 | * on any queue on this host, and attempt to issue it. This may | |
87 | * not be the queue we were asked to process. | |
88 | */ | |
89 | static void mmc_request(request_queue_t *q) | |
90 | { | |
91 | struct mmc_queue *mq = q->queuedata; | |
89b4e133 PO |
92 | struct request *req; |
93 | int ret; | |
94 | ||
95 | if (!mq) { | |
96 | printk(KERN_ERR "MMC: killing requests for dead queue\n"); | |
97 | while ((req = elv_next_request(q)) != NULL) { | |
98 | do { | |
99 | ret = end_that_request_chunk(req, 0, | |
100 | req->current_nr_sectors << 9); | |
101 | } while (ret); | |
102 | } | |
103 | return; | |
104 | } | |
1da177e4 LT |
105 | |
106 | if (!mq->req) | |
87598a2b | 107 | wake_up_process(mq->thread); |
1da177e4 LT |
108 | } |
109 | ||
110 | /** | |
111 | * mmc_init_queue - initialise a queue structure. | |
112 | * @mq: mmc queue | |
113 | * @card: mmc card to attach this queue | |
114 | * @lock: queue lock | |
115 | * | |
116 | * Initialise a MMC card request queue. | |
117 | */ | |
118 | int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card, spinlock_t *lock) | |
119 | { | |
120 | struct mmc_host *host = card->host; | |
121 | u64 limit = BLK_BOUNCE_HIGH; | |
122 | int ret; | |
98ccf149 | 123 | unsigned int bouncesz; |
1da177e4 | 124 | |
fcaf71fd GKH |
125 | if (mmc_dev(host)->dma_mask && *mmc_dev(host)->dma_mask) |
126 | limit = *mmc_dev(host)->dma_mask; | |
1da177e4 LT |
127 | |
128 | mq->card = card; | |
129 | mq->queue = blk_init_queue(mmc_request, lock); | |
130 | if (!mq->queue) | |
131 | return -ENOMEM; | |
132 | ||
1da177e4 LT |
133 | mq->queue->queuedata = mq; |
134 | mq->req = NULL; | |
135 | ||
98ccf149 PO |
136 | blk_queue_prep_rq(mq->queue, mmc_prep_request); |
137 | ||
138 | #ifdef CONFIG_MMC_BLOCK_BOUNCE | |
139 | if (host->max_hw_segs == 1) { | |
140 | bouncesz = MMC_QUEUE_BOUNCESZ; | |
141 | ||
142 | if (bouncesz > host->max_req_size) | |
143 | bouncesz = host->max_req_size; | |
144 | if (bouncesz > host->max_seg_size) | |
145 | bouncesz = host->max_seg_size; | |
146 | ||
147 | mq->bounce_buf = kmalloc(bouncesz, GFP_KERNEL); | |
148 | if (!mq->bounce_buf) { | |
149 | printk(KERN_WARNING "%s: unable to allocate " | |
150 | "bounce buffer\n", mmc_card_name(card)); | |
151 | } else { | |
152 | blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_HIGH); | |
153 | blk_queue_max_sectors(mq->queue, bouncesz / 512); | |
154 | blk_queue_max_phys_segments(mq->queue, bouncesz / 512); | |
155 | blk_queue_max_hw_segments(mq->queue, bouncesz / 512); | |
156 | blk_queue_max_segment_size(mq->queue, bouncesz); | |
157 | ||
158 | mq->sg = kmalloc(sizeof(struct scatterlist), | |
159 | GFP_KERNEL); | |
160 | if (!mq->sg) { | |
161 | ret = -ENOMEM; | |
162 | goto free_bounce_buf; | |
163 | } | |
164 | ||
165 | mq->bounce_sg = kmalloc(sizeof(struct scatterlist) * | |
166 | bouncesz / 512, GFP_KERNEL); | |
167 | if (!mq->bounce_sg) { | |
168 | ret = -ENOMEM; | |
169 | goto free_sg; | |
170 | } | |
171 | } | |
172 | } | |
173 | #endif | |
174 | ||
175 | if (!mq->bounce_buf) { | |
176 | blk_queue_bounce_limit(mq->queue, limit); | |
177 | blk_queue_max_sectors(mq->queue, host->max_req_size / 512); | |
178 | blk_queue_max_phys_segments(mq->queue, host->max_phys_segs); | |
179 | blk_queue_max_hw_segments(mq->queue, host->max_hw_segs); | |
180 | blk_queue_max_segment_size(mq->queue, host->max_seg_size); | |
181 | ||
182 | mq->sg = kmalloc(sizeof(struct scatterlist) * | |
183 | host->max_phys_segs, GFP_KERNEL); | |
184 | if (!mq->sg) { | |
185 | ret = -ENOMEM; | |
186 | goto cleanup_queue; | |
187 | } | |
1da177e4 LT |
188 | } |
189 | ||
1da177e4 LT |
190 | init_MUTEX(&mq->thread_sem); |
191 | ||
87598a2b CH |
192 | mq->thread = kthread_run(mmc_queue_thread, mq, "mmcqd"); |
193 | if (IS_ERR(mq->thread)) { | |
194 | ret = PTR_ERR(mq->thread); | |
98ccf149 | 195 | goto free_bounce_sg; |
1da177e4 LT |
196 | } |
197 | ||
87598a2b | 198 | return 0; |
98ccf149 PO |
199 | free_bounce_sg: |
200 | if (mq->bounce_sg) | |
201 | kfree(mq->bounce_sg); | |
202 | mq->bounce_sg = NULL; | |
87598a2b | 203 | free_sg: |
1da177e4 LT |
204 | kfree(mq->sg); |
205 | mq->sg = NULL; | |
98ccf149 PO |
206 | free_bounce_buf: |
207 | if (mq->bounce_buf) | |
208 | kfree(mq->bounce_buf); | |
209 | mq->bounce_buf = NULL; | |
87598a2b | 210 | cleanup_queue: |
1da177e4 | 211 | blk_cleanup_queue(mq->queue); |
1da177e4 LT |
212 | return ret; |
213 | } | |
1da177e4 LT |
214 | |
215 | void mmc_cleanup_queue(struct mmc_queue *mq) | |
216 | { | |
89b4e133 PO |
217 | request_queue_t *q = mq->queue; |
218 | unsigned long flags; | |
219 | ||
220 | /* Mark that we should start throwing out stragglers */ | |
221 | spin_lock_irqsave(q->queue_lock, flags); | |
222 | q->queuedata = NULL; | |
223 | spin_unlock_irqrestore(q->queue_lock, flags); | |
224 | ||
d2b46f66 PO |
225 | /* Make sure the queue isn't suspended, as that will deadlock */ |
226 | mmc_queue_resume(mq); | |
227 | ||
89b4e133 | 228 | /* Then terminate our worker thread */ |
87598a2b | 229 | kthread_stop(mq->thread); |
1da177e4 | 230 | |
98ccf149 PO |
231 | if (mq->bounce_sg) |
232 | kfree(mq->bounce_sg); | |
233 | mq->bounce_sg = NULL; | |
234 | ||
1da177e4 LT |
235 | kfree(mq->sg); |
236 | mq->sg = NULL; | |
237 | ||
98ccf149 PO |
238 | if (mq->bounce_buf) |
239 | kfree(mq->bounce_buf); | |
240 | mq->bounce_buf = NULL; | |
241 | ||
1da177e4 LT |
242 | blk_cleanup_queue(mq->queue); |
243 | ||
244 | mq->card = NULL; | |
245 | } | |
246 | EXPORT_SYMBOL(mmc_cleanup_queue); | |
247 | ||
248 | /** | |
249 | * mmc_queue_suspend - suspend a MMC request queue | |
250 | * @mq: MMC queue to suspend | |
251 | * | |
252 | * Stop the block request queue, and wait for our thread to | |
253 | * complete any outstanding requests. This ensures that we | |
254 | * won't suspend while a request is being processed. | |
255 | */ | |
256 | void mmc_queue_suspend(struct mmc_queue *mq) | |
257 | { | |
258 | request_queue_t *q = mq->queue; | |
259 | unsigned long flags; | |
260 | ||
261 | if (!(mq->flags & MMC_QUEUE_SUSPENDED)) { | |
262 | mq->flags |= MMC_QUEUE_SUSPENDED; | |
263 | ||
264 | spin_lock_irqsave(q->queue_lock, flags); | |
265 | blk_stop_queue(q); | |
266 | spin_unlock_irqrestore(q->queue_lock, flags); | |
267 | ||
268 | down(&mq->thread_sem); | |
269 | } | |
270 | } | |
1da177e4 LT |
271 | |
272 | /** | |
273 | * mmc_queue_resume - resume a previously suspended MMC request queue | |
274 | * @mq: MMC queue to resume | |
275 | */ | |
276 | void mmc_queue_resume(struct mmc_queue *mq) | |
277 | { | |
278 | request_queue_t *q = mq->queue; | |
279 | unsigned long flags; | |
280 | ||
281 | if (mq->flags & MMC_QUEUE_SUSPENDED) { | |
282 | mq->flags &= ~MMC_QUEUE_SUSPENDED; | |
283 | ||
284 | up(&mq->thread_sem); | |
285 | ||
286 | spin_lock_irqsave(q->queue_lock, flags); | |
287 | blk_start_queue(q); | |
288 | spin_unlock_irqrestore(q->queue_lock, flags); | |
289 | } | |
290 | } | |
98ac2162 | 291 | |
98ccf149 PO |
292 | static void copy_sg(struct scatterlist *dst, unsigned int dst_len, |
293 | struct scatterlist *src, unsigned int src_len) | |
294 | { | |
295 | unsigned int chunk; | |
296 | char *dst_buf, *src_buf; | |
297 | unsigned int dst_size, src_size; | |
298 | ||
299 | dst_buf = NULL; | |
300 | src_buf = NULL; | |
301 | dst_size = 0; | |
302 | src_size = 0; | |
303 | ||
304 | while (src_len) { | |
305 | BUG_ON(dst_len == 0); | |
306 | ||
307 | if (dst_size == 0) { | |
308 | dst_buf = page_address(dst->page) + dst->offset; | |
309 | dst_size = dst->length; | |
310 | } | |
311 | ||
312 | if (src_size == 0) { | |
313 | src_buf = page_address(src->page) + src->offset; | |
314 | src_size = src->length; | |
315 | } | |
316 | ||
317 | chunk = min(dst_size, src_size); | |
318 | ||
319 | memcpy(dst_buf, src_buf, chunk); | |
320 | ||
321 | dst_buf += chunk; | |
322 | src_buf += chunk; | |
323 | dst_size -= chunk; | |
324 | src_size -= chunk; | |
325 | ||
326 | if (dst_size == 0) { | |
327 | dst++; | |
328 | dst_len--; | |
329 | } | |
330 | ||
331 | if (src_size == 0) { | |
332 | src++; | |
333 | src_len--; | |
334 | } | |
335 | } | |
336 | } | |
337 | ||
338 | unsigned int mmc_queue_map_sg(struct mmc_queue *mq) | |
339 | { | |
340 | unsigned int sg_len; | |
341 | ||
342 | if (!mq->bounce_buf) | |
343 | return blk_rq_map_sg(mq->queue, mq->req, mq->sg); | |
344 | ||
345 | BUG_ON(!mq->bounce_sg); | |
346 | ||
347 | sg_len = blk_rq_map_sg(mq->queue, mq->req, mq->bounce_sg); | |
348 | ||
349 | mq->bounce_sg_len = sg_len; | |
350 | ||
351 | /* | |
352 | * Shortcut in the event we only get a single entry. | |
353 | */ | |
354 | if (sg_len == 1) { | |
355 | memcpy(mq->sg, mq->bounce_sg, sizeof(struct scatterlist)); | |
356 | return 1; | |
357 | } | |
358 | ||
359 | mq->sg[0].page = virt_to_page(mq->bounce_buf); | |
360 | mq->sg[0].offset = offset_in_page(mq->bounce_buf); | |
361 | mq->sg[0].length = 0; | |
362 | ||
363 | while (sg_len) { | |
364 | mq->sg[0].length += mq->bounce_sg[sg_len - 1].length; | |
365 | sg_len--; | |
366 | } | |
367 | ||
368 | return 1; | |
369 | } | |
370 | ||
371 | void mmc_queue_bounce_pre(struct mmc_queue *mq) | |
372 | { | |
373 | if (!mq->bounce_buf) | |
374 | return; | |
375 | ||
376 | if (mq->bounce_sg_len == 1) | |
377 | return; | |
378 | if (rq_data_dir(mq->req) != WRITE) | |
379 | return; | |
380 | ||
381 | copy_sg(mq->sg, 1, mq->bounce_sg, mq->bounce_sg_len); | |
382 | } | |
383 | ||
384 | void mmc_queue_bounce_post(struct mmc_queue *mq) | |
385 | { | |
386 | if (!mq->bounce_buf) | |
387 | return; | |
388 | ||
389 | if (mq->bounce_sg_len == 1) | |
390 | return; | |
391 | if (rq_data_dir(mq->req) != READ) | |
392 | return; | |
393 | ||
394 | copy_sg(mq->bounce_sg, mq->bounce_sg_len, mq->sg, 1); | |
395 | } | |
396 |