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#include <linux/dma-mapping.h>
19
20#include <linux/mmc/card.h>
21#include <linux/mmc/host.h>
22#include "queue.h"
23
24#define MMC_QUEUE_BOUNCESZ	65536
25
26/*
27 * Prepare a MMC request. This just filters out odd stuff.
28 */
29static int mmc_prep_request(struct request_queue *q, struct request *req)
30{
31	struct mmc_queue *mq = q->queuedata;
32
33	/*
34	 * We only like normal block requests and discards.
35	 */
36	if (req->cmd_type != REQ_TYPE_FS && !(req->cmd_flags & REQ_DISCARD)) {
37		blk_dump_rq_flags(req, "MMC bad request");
38		return BLKPREP_KILL;
39	}
40
41	if (mq && (mmc_card_removed(mq->card) || mmc_access_rpmb(mq)))
42		return BLKPREP_KILL;
43
44	req->cmd_flags |= REQ_DONTPREP;
45
46	return BLKPREP_OK;
47}
48
49static int mmc_queue_thread(void *d)
50{
51	struct mmc_queue *mq = d;
52	struct request_queue *q = mq->queue;
53
54	current->flags |= PF_MEMALLOC;
55
56	down(&mq->thread_sem);
57	do {
58		struct request *req = NULL;
59		struct mmc_queue_req *tmp;
60		unsigned int cmd_flags = 0;
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			cmd_flags = req ? req->cmd_flags : 0;
71			mq->issue_fn(mq, req);
72			if (mq->flags & MMC_QUEUE_NEW_REQUEST) {
73				mq->flags &= ~MMC_QUEUE_NEW_REQUEST;
74				continue; /* fetch again */
75			}
76
77			/*
78			 * Current request becomes previous request
79			 * and vice versa.
80			 * In case of special requests, current request
81			 * has been finished. Do not assign it to previous
82			 * request.
83			 */
84			if (cmd_flags & MMC_REQ_SPECIAL_MASK)
85				mq->mqrq_cur->req = NULL;
86
87			mq->mqrq_prev->brq.mrq.data = NULL;
88			mq->mqrq_prev->req = NULL;
89			tmp = mq->mqrq_prev;
90			mq->mqrq_prev = mq->mqrq_cur;
91			mq->mqrq_cur = tmp;
92		} else {
93			if (kthread_should_stop()) {
94				set_current_state(TASK_RUNNING);
95				break;
96			}
97			up(&mq->thread_sem);
98			schedule();
99			down(&mq->thread_sem);
100		}
101	} while (1);
102	up(&mq->thread_sem);
103
104	return 0;
105}
106
107/*
108 * Generic MMC request handler.  This is called for any queue on a
109 * particular host.  When the host is not busy, we look for a request
110 * on any queue on this host, and attempt to issue it.  This may
111 * not be the queue we were asked to process.
112 */
113static void mmc_request_fn(struct request_queue *q)
114{
115	struct mmc_queue *mq = q->queuedata;
116	struct request *req;
117	unsigned long flags;
118	struct mmc_context_info *cntx;
119
120	if (!mq) {
121		while ((req = blk_fetch_request(q)) != NULL) {
122			req->cmd_flags |= REQ_QUIET;
123			__blk_end_request_all(req, -EIO);
124		}
125		return;
126	}
127
128	cntx = &mq->card->host->context_info;
129	if (!mq->mqrq_cur->req && mq->mqrq_prev->req) {
130		/*
131		 * New MMC request arrived when MMC thread may be
132		 * blocked on the previous request to be complete
133		 * with no current request fetched
134		 */
135		spin_lock_irqsave(&cntx->lock, flags);
136		if (cntx->is_waiting_last_req) {
137			cntx->is_new_req = true;
138			wake_up_interruptible(&cntx->wait);
139		}
140		spin_unlock_irqrestore(&cntx->lock, flags);
141	} else if (!mq->mqrq_cur->req && !mq->mqrq_prev->req)
142		wake_up_process(mq->thread);
143}
144
145static struct scatterlist *mmc_alloc_sg(int sg_len, int *err)
146{
147	struct scatterlist *sg;
148
149	sg = kmalloc(sizeof(struct scatterlist)*sg_len, GFP_KERNEL);
150	if (!sg)
151		*err = -ENOMEM;
152	else {
153		*err = 0;
154		sg_init_table(sg, sg_len);
155	}
156
157	return sg;
158}
159
160static void mmc_queue_setup_discard(struct request_queue *q,
161				    struct mmc_card *card)
162{
163	unsigned max_discard;
164
165	max_discard = mmc_calc_max_discard(card);
166	if (!max_discard)
167		return;
168
169	queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
170	q->limits.max_discard_sectors = max_discard;
171	if (card->erased_byte == 0 && !mmc_can_discard(card))
172		q->limits.discard_zeroes_data = 1;
173	q->limits.discard_granularity = card->pref_erase << 9;
174	/* granularity must not be greater than max. discard */
175	if (card->pref_erase > max_discard)
176		q->limits.discard_granularity = 0;
177	if (mmc_can_secure_erase_trim(card))
178		queue_flag_set_unlocked(QUEUE_FLAG_SECDISCARD, q);
179}
180
181/**
182 * mmc_init_queue - initialise a queue structure.
183 * @mq: mmc queue
184 * @card: mmc card to attach this queue
185 * @lock: queue lock
186 * @subname: partition subname
187 *
188 * Initialise a MMC card request queue.
189 */
190int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
191		   spinlock_t *lock, const char *subname)
192{
193	struct mmc_host *host = card->host;
194	u64 limit = BLK_BOUNCE_HIGH;
195	int ret;
196	struct mmc_queue_req *mqrq_cur = &mq->mqrq[0];
197	struct mmc_queue_req *mqrq_prev = &mq->mqrq[1];
198
199	if (mmc_dev(host)->dma_mask && *mmc_dev(host)->dma_mask)
200		limit = (u64)dma_max_pfn(mmc_dev(host)) << PAGE_SHIFT;
201
202	mq->card = card;
203	mq->queue = blk_init_queue(mmc_request_fn, lock);
204	if (!mq->queue)
205		return -ENOMEM;
206
207	mq->mqrq_cur = mqrq_cur;
208	mq->mqrq_prev = mqrq_prev;
209	mq->queue->queuedata = mq;
210
211	blk_queue_prep_rq(mq->queue, mmc_prep_request);
212	queue_flag_set_unlocked(QUEUE_FLAG_NONROT, mq->queue);
213	queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, mq->queue);
214	if (mmc_can_erase(card))
215		mmc_queue_setup_discard(mq->queue, card);
216
217#ifdef CONFIG_MMC_BLOCK_BOUNCE
218	if (host->max_segs == 1) {
219		unsigned int bouncesz;
220
221		bouncesz = MMC_QUEUE_BOUNCESZ;
222
223		if (bouncesz > host->max_req_size)
224			bouncesz = host->max_req_size;
225		if (bouncesz > host->max_seg_size)
226			bouncesz = host->max_seg_size;
227		if (bouncesz > (host->max_blk_count * 512))
228			bouncesz = host->max_blk_count * 512;
229
230		if (bouncesz > 512) {
231			mqrq_cur->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
232			if (!mqrq_cur->bounce_buf) {
233				pr_warn("%s: unable to allocate bounce cur buffer\n",
234					mmc_card_name(card));
235			} else {
236				mqrq_prev->bounce_buf =
237						kmalloc(bouncesz, GFP_KERNEL);
238				if (!mqrq_prev->bounce_buf) {
239					pr_warn("%s: unable to allocate bounce prev buffer\n",
240						mmc_card_name(card));
241					kfree(mqrq_cur->bounce_buf);
242					mqrq_cur->bounce_buf = NULL;
243				}
244			}
245		}
246
247		if (mqrq_cur->bounce_buf && mqrq_prev->bounce_buf) {
248			blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_ANY);
249			blk_queue_max_hw_sectors(mq->queue, bouncesz / 512);
250			blk_queue_max_segments(mq->queue, bouncesz / 512);
251			blk_queue_max_segment_size(mq->queue, bouncesz);
252
253			mqrq_cur->sg = mmc_alloc_sg(1, &ret);
254			if (ret)
255				goto cleanup_queue;
256
257			mqrq_cur->bounce_sg =
258				mmc_alloc_sg(bouncesz / 512, &ret);
259			if (ret)
260				goto cleanup_queue;
261
262			mqrq_prev->sg = mmc_alloc_sg(1, &ret);
263			if (ret)
264				goto cleanup_queue;
265
266			mqrq_prev->bounce_sg =
267				mmc_alloc_sg(bouncesz / 512, &ret);
268			if (ret)
269				goto cleanup_queue;
270		}
271	}
272#endif
273
274	if (!mqrq_cur->bounce_buf && !mqrq_prev->bounce_buf) {
275		blk_queue_bounce_limit(mq->queue, limit);
276		blk_queue_max_hw_sectors(mq->queue,
277			min(host->max_blk_count, host->max_req_size / 512));
278		blk_queue_max_segments(mq->queue, host->max_segs);
279		blk_queue_max_segment_size(mq->queue, host->max_seg_size);
280
281		mqrq_cur->sg = mmc_alloc_sg(host->max_segs, &ret);
282		if (ret)
283			goto cleanup_queue;
284
285
286		mqrq_prev->sg = mmc_alloc_sg(host->max_segs, &ret);
287		if (ret)
288			goto cleanup_queue;
289	}
290
291	sema_init(&mq->thread_sem, 1);
292
293	mq->thread = kthread_run(mmc_queue_thread, mq, "mmcqd/%d%s",
294		host->index, subname ? subname : "");
295
296	if (IS_ERR(mq->thread)) {
297		ret = PTR_ERR(mq->thread);
298		goto free_bounce_sg;
299	}
300
301	return 0;
302 free_bounce_sg:
303	kfree(mqrq_cur->bounce_sg);
304	mqrq_cur->bounce_sg = NULL;
305	kfree(mqrq_prev->bounce_sg);
306	mqrq_prev->bounce_sg = NULL;
307
308 cleanup_queue:
309	kfree(mqrq_cur->sg);
310	mqrq_cur->sg = NULL;
311	kfree(mqrq_cur->bounce_buf);
312	mqrq_cur->bounce_buf = NULL;
313
314	kfree(mqrq_prev->sg);
315	mqrq_prev->sg = NULL;
316	kfree(mqrq_prev->bounce_buf);
317	mqrq_prev->bounce_buf = NULL;
318
319	blk_cleanup_queue(mq->queue);
320	return ret;
321}
322
323void mmc_cleanup_queue(struct mmc_queue *mq)
324{
325	struct request_queue *q = mq->queue;
326	unsigned long flags;
327	struct mmc_queue_req *mqrq_cur = mq->mqrq_cur;
328	struct mmc_queue_req *mqrq_prev = mq->mqrq_prev;
329
330	/* Make sure the queue isn't suspended, as that will deadlock */
331	mmc_queue_resume(mq);
332
333	/* Then terminate our worker thread */
334	kthread_stop(mq->thread);
335
336	/* Empty the queue */
337	spin_lock_irqsave(q->queue_lock, flags);
338	q->queuedata = NULL;
339	blk_start_queue(q);
340	spin_unlock_irqrestore(q->queue_lock, flags);
341
342	kfree(mqrq_cur->bounce_sg);
343	mqrq_cur->bounce_sg = NULL;
344
345	kfree(mqrq_cur->sg);
346	mqrq_cur->sg = NULL;
347
348	kfree(mqrq_cur->bounce_buf);
349	mqrq_cur->bounce_buf = NULL;
350
351	kfree(mqrq_prev->bounce_sg);
352	mqrq_prev->bounce_sg = NULL;
353
354	kfree(mqrq_prev->sg);
355	mqrq_prev->sg = NULL;
356
357	kfree(mqrq_prev->bounce_buf);
358	mqrq_prev->bounce_buf = NULL;
359
360	mq->card = NULL;
361}
362EXPORT_SYMBOL(mmc_cleanup_queue);
363
364int mmc_packed_init(struct mmc_queue *mq, struct mmc_card *card)
365{
366	struct mmc_queue_req *mqrq_cur = &mq->mqrq[0];
367	struct mmc_queue_req *mqrq_prev = &mq->mqrq[1];
368	int ret = 0;
369
370
371	mqrq_cur->packed = kzalloc(sizeof(struct mmc_packed), GFP_KERNEL);
372	if (!mqrq_cur->packed) {
373		pr_warn("%s: unable to allocate packed cmd for mqrq_cur\n",
374			mmc_card_name(card));
375		ret = -ENOMEM;
376		goto out;
377	}
378
379	mqrq_prev->packed = kzalloc(sizeof(struct mmc_packed), GFP_KERNEL);
380	if (!mqrq_prev->packed) {
381		pr_warn("%s: unable to allocate packed cmd for mqrq_prev\n",
382			mmc_card_name(card));
383		kfree(mqrq_cur->packed);
384		mqrq_cur->packed = NULL;
385		ret = -ENOMEM;
386		goto out;
387	}
388
389	INIT_LIST_HEAD(&mqrq_cur->packed->list);
390	INIT_LIST_HEAD(&mqrq_prev->packed->list);
391
392out:
393	return ret;
394}
395
396void mmc_packed_clean(struct mmc_queue *mq)
397{
398	struct mmc_queue_req *mqrq_cur = &mq->mqrq[0];
399	struct mmc_queue_req *mqrq_prev = &mq->mqrq[1];
400
401	kfree(mqrq_cur->packed);
402	mqrq_cur->packed = NULL;
403	kfree(mqrq_prev->packed);
404	mqrq_prev->packed = NULL;
405}
406
407/**
408 * mmc_queue_suspend - suspend a MMC request queue
409 * @mq: MMC queue to suspend
410 *
411 * Stop the block request queue, and wait for our thread to
412 * complete any outstanding requests.  This ensures that we
413 * won't suspend while a request is being processed.
414 */
415void mmc_queue_suspend(struct mmc_queue *mq)
416{
417	struct request_queue *q = mq->queue;
418	unsigned long flags;
419
420	if (!(mq->flags & MMC_QUEUE_SUSPENDED)) {
421		mq->flags |= MMC_QUEUE_SUSPENDED;
422
423		spin_lock_irqsave(q->queue_lock, flags);
424		blk_stop_queue(q);
425		spin_unlock_irqrestore(q->queue_lock, flags);
426
427		down(&mq->thread_sem);
428	}
429}
430
431/**
432 * mmc_queue_resume - resume a previously suspended MMC request queue
433 * @mq: MMC queue to resume
434 */
435void mmc_queue_resume(struct mmc_queue *mq)
436{
437	struct request_queue *q = mq->queue;
438	unsigned long flags;
439
440	if (mq->flags & MMC_QUEUE_SUSPENDED) {
441		mq->flags &= ~MMC_QUEUE_SUSPENDED;
442
443		up(&mq->thread_sem);
444
445		spin_lock_irqsave(q->queue_lock, flags);
446		blk_start_queue(q);
447		spin_unlock_irqrestore(q->queue_lock, flags);
448	}
449}
450
451static unsigned int mmc_queue_packed_map_sg(struct mmc_queue *mq,
452					    struct mmc_packed *packed,
453					    struct scatterlist *sg,
454					    enum mmc_packed_type cmd_type)
455{
456	struct scatterlist *__sg = sg;
457	unsigned int sg_len = 0;
458	struct request *req;
459
460	if (mmc_packed_wr(cmd_type)) {
461		unsigned int hdr_sz = mmc_large_sector(mq->card) ? 4096 : 512;
462		unsigned int max_seg_sz = queue_max_segment_size(mq->queue);
463		unsigned int len, remain, offset = 0;
464		u8 *buf = (u8 *)packed->cmd_hdr;
465
466		remain = hdr_sz;
467		do {
468			len = min(remain, max_seg_sz);
469			sg_set_buf(__sg, buf + offset, len);
470			offset += len;
471			remain -= len;
472			(__sg++)->page_link &= ~0x02;
473			sg_len++;
474		} while (remain);
475	}
476
477	list_for_each_entry(req, &packed->list, queuelist) {
478		sg_len += blk_rq_map_sg(mq->queue, req, __sg);
479		__sg = sg + (sg_len - 1);
480		(__sg++)->page_link &= ~0x02;
481	}
482	sg_mark_end(sg + (sg_len - 1));
483	return sg_len;
484}
485
486/*
487 * Prepare the sg list(s) to be handed of to the host driver
488 */
489unsigned int mmc_queue_map_sg(struct mmc_queue *mq, struct mmc_queue_req *mqrq)
490{
491	unsigned int sg_len;
492	size_t buflen;
493	struct scatterlist *sg;
494	enum mmc_packed_type cmd_type;
495	int i;
496
497	cmd_type = mqrq->cmd_type;
498
499	if (!mqrq->bounce_buf) {
500		if (mmc_packed_cmd(cmd_type))
501			return mmc_queue_packed_map_sg(mq, mqrq->packed,
502						       mqrq->sg, cmd_type);
503		else
504			return blk_rq_map_sg(mq->queue, mqrq->req, mqrq->sg);
505	}
506
507	BUG_ON(!mqrq->bounce_sg);
508
509	if (mmc_packed_cmd(cmd_type))
510		sg_len = mmc_queue_packed_map_sg(mq, mqrq->packed,
511						 mqrq->bounce_sg, cmd_type);
512	else
513		sg_len = blk_rq_map_sg(mq->queue, mqrq->req, mqrq->bounce_sg);
514
515	mqrq->bounce_sg_len = sg_len;
516
517	buflen = 0;
518	for_each_sg(mqrq->bounce_sg, sg, sg_len, i)
519		buflen += sg->length;
520
521	sg_init_one(mqrq->sg, mqrq->bounce_buf, buflen);
522
523	return 1;
524}
525
526/*
527 * If writing, bounce the data to the buffer before the request
528 * is sent to the host driver
529 */
530void mmc_queue_bounce_pre(struct mmc_queue_req *mqrq)
531{
532	if (!mqrq->bounce_buf)
533		return;
534
535	if (rq_data_dir(mqrq->req) != WRITE)
536		return;
537
538	sg_copy_to_buffer(mqrq->bounce_sg, mqrq->bounce_sg_len,
539		mqrq->bounce_buf, mqrq->sg[0].length);
540}
541
542/*
543 * If reading, bounce the data from the buffer after the request
544 * has been handled by the host driver
545 */
546void mmc_queue_bounce_post(struct mmc_queue_req *mqrq)
547{
548	if (!mqrq->bounce_buf)
549		return;
550
551	if (rq_data_dir(mqrq->req) != READ)
552		return;
553
554	sg_copy_from_buffer(mqrq->bounce_sg, mqrq->bounce_sg_len,
555		mqrq->bounce_buf, mqrq->sg[0].length);
556}
557