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[~shefty/rdma-dev.git] / drivers / mmc / card / queue.c
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  */
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
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  */
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
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
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  */
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
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  */
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  */
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  */
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  */
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  */
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 }