1 /*
2 * linux/drivers/mmc/card/queue.c
3 *
4 * Copyright (C) 2003 Russell King, All Rights Reserved.
5 * Copyright 2006-2007 Pierre Ossman
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/slab.h>
13 #include <linux/module.h>
14 #include <linux/blkdev.h>
15 #include <linux/freezer.h>
16 #include <linux/kthread.h>
17 #include <linux/scatterlist.h>
18
19 #include <linux/mmc/card.h>
20 #include <linux/mmc/host.h>
21 #include "queue.h"
22
23 #define MMC_QUEUE_BOUNCESZ 65536
24
25 #define MMC_QUEUE_SUSPENDED (1 << 0)
26
27 /*
28 * Prepare a MMC request. This just filters out odd stuff.
29 */
mmc_prep_request(struct request_queue * q,struct request * req)30 static int mmc_prep_request(struct request_queue *q, struct request *req)
31 {
32 struct mmc_queue *mq = q->queuedata;
33
34 /*
35 * We only like normal block requests and discards.
36 */
37 if (req->cmd_type != REQ_TYPE_FS && !(req->cmd_flags & REQ_DISCARD)) {
38 blk_dump_rq_flags(req, "MMC bad request");
39 return BLKPREP_KILL;
40 }
41
42 if (mq && mmc_card_removed(mq->card))
43 return BLKPREP_KILL;
44
45 req->cmd_flags |= REQ_DONTPREP;
46
47 return BLKPREP_OK;
48 }
49
mmc_queue_thread(void * d)50 static int mmc_queue_thread(void *d)
51 {
52 struct mmc_queue *mq = d;
53 struct request_queue *q = mq->queue;
54
55 current->flags |= PF_MEMALLOC;
56
57 down(&mq->thread_sem);
58 do {
59 struct request *req = NULL;
60 struct mmc_queue_req *tmp;
61
62 spin_lock_irq(q->queue_lock);
63 set_current_state(TASK_INTERRUPTIBLE);
64 req = blk_fetch_request(q);
65 mq->mqrq_cur->req = req;
66 spin_unlock_irq(q->queue_lock);
67
68 if (req || mq->mqrq_prev->req) {
69 set_current_state(TASK_RUNNING);
70 mq->issue_fn(mq, req);
71 } else {
72 if (kthread_should_stop()) {
73 set_current_state(TASK_RUNNING);
74 break;
75 }
76 up(&mq->thread_sem);
77 schedule();
78 down(&mq->thread_sem);
79 }
80
81 /* Current request becomes previous request and vice versa. */
82 mq->mqrq_prev->brq.mrq.data = NULL;
83 mq->mqrq_prev->req = NULL;
84 tmp = mq->mqrq_prev;
85 mq->mqrq_prev = mq->mqrq_cur;
86 mq->mqrq_cur = tmp;
87 } while (1);
88 up(&mq->thread_sem);
89
90 return 0;
91 }
92
93 /*
94 * Generic MMC request handler. This is called for any queue on a
95 * particular host. When the host is not busy, we look for a request
96 * on any queue on this host, and attempt to issue it. This may
97 * not be the queue we were asked to process.
98 */
mmc_request(struct request_queue * q)99 static void mmc_request(struct request_queue *q)
100 {
101 struct mmc_queue *mq = q->queuedata;
102 struct request *req;
103
104 if (!mq) {
105 while ((req = blk_fetch_request(q)) != NULL) {
106 req->cmd_flags |= REQ_QUIET;
107 __blk_end_request_all(req, -EIO);
108 }
109 return;
110 }
111
112 if (!mq->mqrq_cur->req && !mq->mqrq_prev->req)
113 wake_up_process(mq->thread);
114 }
115
mmc_alloc_sg(int sg_len,int * err)116 static struct scatterlist *mmc_alloc_sg(int sg_len, int *err)
117 {
118 struct scatterlist *sg;
119
120 sg = kmalloc(sizeof(struct scatterlist)*sg_len, GFP_KERNEL);
121 if (!sg)
122 *err = -ENOMEM;
123 else {
124 *err = 0;
125 sg_init_table(sg, sg_len);
126 }
127
128 return sg;
129 }
130
mmc_queue_setup_discard(struct request_queue * q,struct mmc_card * card)131 static void mmc_queue_setup_discard(struct request_queue *q,
132 struct mmc_card *card)
133 {
134 unsigned max_discard;
135
136 max_discard = mmc_calc_max_discard(card);
137 if (!max_discard)
138 return;
139
140 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
141 q->limits.max_discard_sectors = max_discard;
142 if (card->erased_byte == 0)
143 q->limits.discard_zeroes_data = 1;
144 q->limits.discard_granularity = card->pref_erase << 9;
145 /* granularity must not be greater than max. discard */
146 if (card->pref_erase > max_discard)
147 q->limits.discard_granularity = 0;
148 if (mmc_can_secure_erase_trim(card) || mmc_can_sanitize(card))
149 queue_flag_set_unlocked(QUEUE_FLAG_SECDISCARD, q);
150 }
151
152 /**
153 * mmc_init_queue - initialise a queue structure.
154 * @mq: mmc queue
155 * @card: mmc card to attach this queue
156 * @lock: queue lock
157 * @subname: partition subname
158 *
159 * Initialise a MMC card request queue.
160 */
mmc_init_queue(struct mmc_queue * mq,struct mmc_card * card,spinlock_t * lock,const char * subname)161 int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
162 spinlock_t *lock, const char *subname)
163 {
164 struct mmc_host *host = card->host;
165 u64 limit = BLK_BOUNCE_HIGH;
166 int ret;
167 struct mmc_queue_req *mqrq_cur = &mq->mqrq[0];
168 struct mmc_queue_req *mqrq_prev = &mq->mqrq[1];
169
170 if (mmc_dev(host)->dma_mask && *mmc_dev(host)->dma_mask)
171 limit = *mmc_dev(host)->dma_mask;
172
173 mq->card = card;
174 mq->queue = blk_init_queue(mmc_request, lock);
175 if (!mq->queue)
176 return -ENOMEM;
177
178 memset(&mq->mqrq_cur, 0, sizeof(mq->mqrq_cur));
179 memset(&mq->mqrq_prev, 0, sizeof(mq->mqrq_prev));
180 mq->mqrq_cur = mqrq_cur;
181 mq->mqrq_prev = mqrq_prev;
182 mq->queue->queuedata = mq;
183
184 blk_queue_prep_rq(mq->queue, mmc_prep_request);
185 queue_flag_set_unlocked(QUEUE_FLAG_NONROT, mq->queue);
186 if (mmc_can_erase(card))
187 mmc_queue_setup_discard(mq->queue, card);
188
189 #ifdef CONFIG_MMC_BLOCK_BOUNCE
190 if (host->max_segs == 1) {
191 unsigned int bouncesz;
192
193 bouncesz = MMC_QUEUE_BOUNCESZ;
194
195 if (bouncesz > host->max_req_size)
196 bouncesz = host->max_req_size;
197 if (bouncesz > host->max_seg_size)
198 bouncesz = host->max_seg_size;
199 if (bouncesz > (host->max_blk_count * 512))
200 bouncesz = host->max_blk_count * 512;
201
202 if (bouncesz > 512) {
203 mqrq_cur->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
204 if (!mqrq_cur->bounce_buf) {
205 pr_warning("%s: unable to "
206 "allocate bounce cur buffer\n",
207 mmc_card_name(card));
208 }
209 mqrq_prev->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
210 if (!mqrq_prev->bounce_buf) {
211 pr_warning("%s: unable to "
212 "allocate bounce prev buffer\n",
213 mmc_card_name(card));
214 kfree(mqrq_cur->bounce_buf);
215 mqrq_cur->bounce_buf = NULL;
216 }
217 }
218
219 if (mqrq_cur->bounce_buf && mqrq_prev->bounce_buf) {
220 blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_ANY);
221 blk_queue_max_hw_sectors(mq->queue, bouncesz / 512);
222 blk_queue_max_segments(mq->queue, bouncesz / 512);
223 blk_queue_max_segment_size(mq->queue, bouncesz);
224
225 mqrq_cur->sg = mmc_alloc_sg(1, &ret);
226 if (ret)
227 goto cleanup_queue;
228
229 mqrq_cur->bounce_sg =
230 mmc_alloc_sg(bouncesz / 512, &ret);
231 if (ret)
232 goto cleanup_queue;
233
234 mqrq_prev->sg = mmc_alloc_sg(1, &ret);
235 if (ret)
236 goto cleanup_queue;
237
238 mqrq_prev->bounce_sg =
239 mmc_alloc_sg(bouncesz / 512, &ret);
240 if (ret)
241 goto cleanup_queue;
242 }
243 }
244 #endif
245
246 if (!mqrq_cur->bounce_buf && !mqrq_prev->bounce_buf) {
247 blk_queue_bounce_limit(mq->queue, limit);
248 blk_queue_max_hw_sectors(mq->queue,
249 min(host->max_blk_count, host->max_req_size / 512));
250 blk_queue_max_segments(mq->queue, host->max_segs);
251 blk_queue_max_segment_size(mq->queue, host->max_seg_size);
252
253 mqrq_cur->sg = mmc_alloc_sg(host->max_segs, &ret);
254 if (ret)
255 goto cleanup_queue;
256
257
258 mqrq_prev->sg = mmc_alloc_sg(host->max_segs, &ret);
259 if (ret)
260 goto cleanup_queue;
261 }
262
263 sema_init(&mq->thread_sem, 1);
264
265 mq->thread = kthread_run(mmc_queue_thread, mq, "mmcqd/%d%s",
266 host->index, subname ? subname : "");
267
268 if (IS_ERR(mq->thread)) {
269 ret = PTR_ERR(mq->thread);
270 goto free_bounce_sg;
271 }
272
273 return 0;
274 free_bounce_sg:
275 kfree(mqrq_cur->bounce_sg);
276 mqrq_cur->bounce_sg = NULL;
277 kfree(mqrq_prev->bounce_sg);
278 mqrq_prev->bounce_sg = NULL;
279
280 cleanup_queue:
281 kfree(mqrq_cur->sg);
282 mqrq_cur->sg = NULL;
283 kfree(mqrq_cur->bounce_buf);
284 mqrq_cur->bounce_buf = NULL;
285
286 kfree(mqrq_prev->sg);
287 mqrq_prev->sg = NULL;
288 kfree(mqrq_prev->bounce_buf);
289 mqrq_prev->bounce_buf = NULL;
290
291 blk_cleanup_queue(mq->queue);
292 return ret;
293 }
294
mmc_cleanup_queue(struct mmc_queue * mq)295 void mmc_cleanup_queue(struct mmc_queue *mq)
296 {
297 struct request_queue *q = mq->queue;
298 unsigned long flags;
299 struct mmc_queue_req *mqrq_cur = mq->mqrq_cur;
300 struct mmc_queue_req *mqrq_prev = mq->mqrq_prev;
301
302 /* Make sure the queue isn't suspended, as that will deadlock */
303 mmc_queue_resume(mq);
304
305 /* Then terminate our worker thread */
306 kthread_stop(mq->thread);
307
308 /* Empty the queue */
309 spin_lock_irqsave(q->queue_lock, flags);
310 q->queuedata = NULL;
311 blk_start_queue(q);
312 spin_unlock_irqrestore(q->queue_lock, flags);
313
314 kfree(mqrq_cur->bounce_sg);
315 mqrq_cur->bounce_sg = NULL;
316
317 kfree(mqrq_cur->sg);
318 mqrq_cur->sg = NULL;
319
320 kfree(mqrq_cur->bounce_buf);
321 mqrq_cur->bounce_buf = NULL;
322
323 kfree(mqrq_prev->bounce_sg);
324 mqrq_prev->bounce_sg = NULL;
325
326 kfree(mqrq_prev->sg);
327 mqrq_prev->sg = NULL;
328
329 kfree(mqrq_prev->bounce_buf);
330 mqrq_prev->bounce_buf = NULL;
331
332 mq->card = NULL;
333 }
334 EXPORT_SYMBOL(mmc_cleanup_queue);
335
336 /**
337 * mmc_queue_suspend - suspend a MMC request queue
338 * @mq: MMC queue to suspend
339 *
340 * Stop the block request queue, and wait for our thread to
341 * complete any outstanding requests. This ensures that we
342 * won't suspend while a request is being processed.
343 */
mmc_queue_suspend(struct mmc_queue * mq)344 void mmc_queue_suspend(struct mmc_queue *mq)
345 {
346 struct request_queue *q = mq->queue;
347 unsigned long flags;
348
349 if (!(mq->flags & MMC_QUEUE_SUSPENDED)) {
350 mq->flags |= MMC_QUEUE_SUSPENDED;
351
352 spin_lock_irqsave(q->queue_lock, flags);
353 blk_stop_queue(q);
354 spin_unlock_irqrestore(q->queue_lock, flags);
355
356 down(&mq->thread_sem);
357 }
358 }
359
360 /**
361 * mmc_queue_resume - resume a previously suspended MMC request queue
362 * @mq: MMC queue to resume
363 */
mmc_queue_resume(struct mmc_queue * mq)364 void mmc_queue_resume(struct mmc_queue *mq)
365 {
366 struct request_queue *q = mq->queue;
367 unsigned long flags;
368
369 if (mq->flags & MMC_QUEUE_SUSPENDED) {
370 mq->flags &= ~MMC_QUEUE_SUSPENDED;
371
372 up(&mq->thread_sem);
373
374 spin_lock_irqsave(q->queue_lock, flags);
375 blk_start_queue(q);
376 spin_unlock_irqrestore(q->queue_lock, flags);
377 }
378 }
379
380 /*
381 * Prepare the sg list(s) to be handed of to the host driver
382 */
mmc_queue_map_sg(struct mmc_queue * mq,struct mmc_queue_req * mqrq)383 unsigned int mmc_queue_map_sg(struct mmc_queue *mq, struct mmc_queue_req *mqrq)
384 {
385 unsigned int sg_len;
386 size_t buflen;
387 struct scatterlist *sg;
388 int i;
389
390 if (!mqrq->bounce_buf)
391 return blk_rq_map_sg(mq->queue, mqrq->req, mqrq->sg);
392
393 BUG_ON(!mqrq->bounce_sg);
394
395 sg_len = blk_rq_map_sg(mq->queue, mqrq->req, mqrq->bounce_sg);
396
397 mqrq->bounce_sg_len = sg_len;
398
399 buflen = 0;
400 for_each_sg(mqrq->bounce_sg, sg, sg_len, i)
401 buflen += sg->length;
402
403 sg_init_one(mqrq->sg, mqrq->bounce_buf, buflen);
404
405 return 1;
406 }
407
408 /*
409 * If writing, bounce the data to the buffer before the request
410 * is sent to the host driver
411 */
mmc_queue_bounce_pre(struct mmc_queue_req * mqrq)412 void mmc_queue_bounce_pre(struct mmc_queue_req *mqrq)
413 {
414 if (!mqrq->bounce_buf)
415 return;
416
417 if (rq_data_dir(mqrq->req) != WRITE)
418 return;
419
420 sg_copy_to_buffer(mqrq->bounce_sg, mqrq->bounce_sg_len,
421 mqrq->bounce_buf, mqrq->sg[0].length);
422 }
423
424 /*
425 * If reading, bounce the data from the buffer after the request
426 * has been handled by the host driver
427 */
mmc_queue_bounce_post(struct mmc_queue_req * mqrq)428 void mmc_queue_bounce_post(struct mmc_queue_req *mqrq)
429 {
430 if (!mqrq->bounce_buf)
431 return;
432
433 if (rq_data_dir(mqrq->req) != READ)
434 return;
435
436 sg_copy_from_buffer(mqrq->bounce_sg, mqrq->bounce_sg_len,
437 mqrq->bounce_buf, mqrq->sg[0].length);
438 }
439