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1/*
2 * Copyright (C) 2003 Russell King, All Rights Reserved.
3 * Copyright 2006-2007 Pierre Ossman
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 *
9 */
10#include <linux/slab.h>
11#include <linux/module.h>
12#include <linux/blkdev.h>
13#include <linux/freezer.h>
14#include <linux/kthread.h>
15#include <linux/scatterlist.h>
16#include <linux/dma-mapping.h>
17
18#include <linux/mmc/card.h>
19#include <linux/mmc/host.h>
20
21#include "queue.h"
22#include "block.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_op(req) != REQ_OP_DISCARD &&
37 req_op(req) != REQ_OP_SECURE_ERASE) {
38 blk_dump_rq_flags(req, "MMC bad request");
39 return BLKPREP_KILL;
40 }
41
42 if (mq && (mmc_card_removed(mq->card) || mmc_access_rpmb(mq)))
43 return BLKPREP_KILL;
44
45 req->rq_flags |= RQF_DONTPREP;
46
47 return BLKPREP_OK;
48}
49
50static int mmc_queue_thread(void *d)
51{
52 struct mmc_queue *mq = d;
53 struct request_queue *q = mq->queue;
54 struct mmc_context_info *cntx = &mq->card->host->context_info;
55
56 current->flags |= PF_MEMALLOC;
57
58 down(&mq->thread_sem);
59 do {
60 struct request *req = NULL;
61
62 spin_lock_irq(q->queue_lock);
63 set_current_state(TASK_INTERRUPTIBLE);
64 req = blk_fetch_request(q);
65 mq->asleep = false;
66 cntx->is_waiting_last_req = false;
67 cntx->is_new_req = false;
68 if (!req) {
69 /*
70 * Dispatch queue is empty so set flags for
71 * mmc_request_fn() to wake us up.
72 */
73 if (mq->mqrq_prev->req)
74 cntx->is_waiting_last_req = true;
75 else
76 mq->asleep = true;
77 }
78 mq->mqrq_cur->req = req;
79 spin_unlock_irq(q->queue_lock);
80
81 if (req || mq->mqrq_prev->req) {
82 bool req_is_special = mmc_req_is_special(req);
83
84 set_current_state(TASK_RUNNING);
85 mmc_blk_issue_rq(mq, req);
86 cond_resched();
87 if (mq->flags & MMC_QUEUE_NEW_REQUEST) {
88 mq->flags &= ~MMC_QUEUE_NEW_REQUEST;
89 continue; /* fetch again */
90 }
91
92 /*
93 * Current request becomes previous request
94 * and vice versa.
95 * In case of special requests, current request
96 * has been finished. Do not assign it to previous
97 * request.
98 */
99 if (req_is_special)
100 mq->mqrq_cur->req = NULL;
101
102 mq->mqrq_prev->brq.mrq.data = NULL;
103 mq->mqrq_prev->req = NULL;
104 swap(mq->mqrq_prev, mq->mqrq_cur);
105 } else {
106 if (kthread_should_stop()) {
107 set_current_state(TASK_RUNNING);
108 break;
109 }
110 up(&mq->thread_sem);
111 schedule();
112 down(&mq->thread_sem);
113 }
114 } while (1);
115 up(&mq->thread_sem);
116
117 return 0;
118}
119
120/*
121 * Generic MMC request handler. This is called for any queue on a
122 * particular host. When the host is not busy, we look for a request
123 * on any queue on this host, and attempt to issue it. This may
124 * not be the queue we were asked to process.
125 */
126static void mmc_request_fn(struct request_queue *q)
127{
128 struct mmc_queue *mq = q->queuedata;
129 struct request *req;
130 struct mmc_context_info *cntx;
131
132 if (!mq) {
133 while ((req = blk_fetch_request(q)) != NULL) {
134 req->rq_flags |= RQF_QUIET;
135 __blk_end_request_all(req, -EIO);
136 }
137 return;
138 }
139
140 cntx = &mq->card->host->context_info;
141
142 if (cntx->is_waiting_last_req) {
143 cntx->is_new_req = true;
144 wake_up_interruptible(&cntx->wait);
145 }
146
147 if (mq->asleep)
148 wake_up_process(mq->thread);
149}
150
151static struct scatterlist *mmc_alloc_sg(int sg_len, int *err)
152{
153 struct scatterlist *sg;
154
155 sg = kmalloc(sizeof(struct scatterlist)*sg_len, GFP_KERNEL);
156 if (!sg)
157 *err = -ENOMEM;
158 else {
159 *err = 0;
160 sg_init_table(sg, sg_len);
161 }
162
163 return sg;
164}
165
166static void mmc_queue_setup_discard(struct request_queue *q,
167 struct mmc_card *card)
168{
169 unsigned max_discard;
170
171 max_discard = mmc_calc_max_discard(card);
172 if (!max_discard)
173 return;
174
175 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
176 blk_queue_max_discard_sectors(q, max_discard);
177 if (card->erased_byte == 0 && !mmc_can_discard(card))
178 q->limits.discard_zeroes_data = 1;
179 q->limits.discard_granularity = card->pref_erase << 9;
180 /* granularity must not be greater than max. discard */
181 if (card->pref_erase > max_discard)
182 q->limits.discard_granularity = 0;
183 if (mmc_can_secure_erase_trim(card))
184 queue_flag_set_unlocked(QUEUE_FLAG_SECERASE, q);
185}
186
187#ifdef CONFIG_MMC_BLOCK_BOUNCE
188static bool mmc_queue_alloc_bounce_bufs(struct mmc_queue *mq,
189 unsigned int bouncesz)
190{
191 int i;
192
193 for (i = 0; i < mq->qdepth; i++) {
194 mq->mqrq[i].bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
195 if (!mq->mqrq[i].bounce_buf)
196 goto out_err;
197 }
198
199 return true;
200
201out_err:
202 while (--i >= 0) {
203 kfree(mq->mqrq[i].bounce_buf);
204 mq->mqrq[i].bounce_buf = NULL;
205 }
206 pr_warn("%s: unable to allocate bounce buffers\n",
207 mmc_card_name(mq->card));
208 return false;
209}
210
211static int mmc_queue_alloc_bounce_sgs(struct mmc_queue *mq,
212 unsigned int bouncesz)
213{
214 int i, ret;
215
216 for (i = 0; i < mq->qdepth; i++) {
217 mq->mqrq[i].sg = mmc_alloc_sg(1, &ret);
218 if (ret)
219 return ret;
220
221 mq->mqrq[i].bounce_sg = mmc_alloc_sg(bouncesz / 512, &ret);
222 if (ret)
223 return ret;
224 }
225
226 return 0;
227}
228#endif
229
230static int mmc_queue_alloc_sgs(struct mmc_queue *mq, int max_segs)
231{
232 int i, ret;
233
234 for (i = 0; i < mq->qdepth; i++) {
235 mq->mqrq[i].sg = mmc_alloc_sg(max_segs, &ret);
236 if (ret)
237 return ret;
238 }
239
240 return 0;
241}
242
243static void mmc_queue_req_free_bufs(struct mmc_queue_req *mqrq)
244{
245 kfree(mqrq->bounce_sg);
246 mqrq->bounce_sg = NULL;
247
248 kfree(mqrq->sg);
249 mqrq->sg = NULL;
250
251 kfree(mqrq->bounce_buf);
252 mqrq->bounce_buf = NULL;
253}
254
255static void mmc_queue_reqs_free_bufs(struct mmc_queue *mq)
256{
257 int i;
258
259 for (i = 0; i < mq->qdepth; i++)
260 mmc_queue_req_free_bufs(&mq->mqrq[i]);
261}
262
263/**
264 * mmc_init_queue - initialise a queue structure.
265 * @mq: mmc queue
266 * @card: mmc card to attach this queue
267 * @lock: queue lock
268 * @subname: partition subname
269 *
270 * Initialise a MMC card request queue.
271 */
272int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
273 spinlock_t *lock, const char *subname)
274{
275 struct mmc_host *host = card->host;
276 u64 limit = BLK_BOUNCE_HIGH;
277 bool bounce = false;
278 int ret = -ENOMEM;
279
280 if (mmc_dev(host)->dma_mask && *mmc_dev(host)->dma_mask)
281 limit = (u64)dma_max_pfn(mmc_dev(host)) << PAGE_SHIFT;
282
283 mq->card = card;
284 mq->queue = blk_init_queue(mmc_request_fn, lock);
285 if (!mq->queue)
286 return -ENOMEM;
287
288 mq->qdepth = 2;
289 mq->mqrq = kcalloc(mq->qdepth, sizeof(struct mmc_queue_req),
290 GFP_KERNEL);
291 if (!mq->mqrq)
292 goto blk_cleanup;
293 mq->mqrq_cur = &mq->mqrq[0];
294 mq->mqrq_prev = &mq->mqrq[1];
295 mq->queue->queuedata = mq;
296
297 blk_queue_prep_rq(mq->queue, mmc_prep_request);
298 queue_flag_set_unlocked(QUEUE_FLAG_NONROT, mq->queue);
299 queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, mq->queue);
300 if (mmc_can_erase(card))
301 mmc_queue_setup_discard(mq->queue, card);
302
303#ifdef CONFIG_MMC_BLOCK_BOUNCE
304 if (host->max_segs == 1) {
305 unsigned int bouncesz;
306
307 bouncesz = MMC_QUEUE_BOUNCESZ;
308
309 if (bouncesz > host->max_req_size)
310 bouncesz = host->max_req_size;
311 if (bouncesz > host->max_seg_size)
312 bouncesz = host->max_seg_size;
313 if (bouncesz > (host->max_blk_count * 512))
314 bouncesz = host->max_blk_count * 512;
315
316 if (bouncesz > 512 &&
317 mmc_queue_alloc_bounce_bufs(mq, bouncesz)) {
318 blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_ANY);
319 blk_queue_max_hw_sectors(mq->queue, bouncesz / 512);
320 blk_queue_max_segments(mq->queue, bouncesz / 512);
321 blk_queue_max_segment_size(mq->queue, bouncesz);
322
323 ret = mmc_queue_alloc_bounce_sgs(mq, bouncesz);
324 if (ret)
325 goto cleanup_queue;
326 bounce = true;
327 }
328 }
329#endif
330
331 if (!bounce) {
332 blk_queue_bounce_limit(mq->queue, limit);
333 blk_queue_max_hw_sectors(mq->queue,
334 min(host->max_blk_count, host->max_req_size / 512));
335 blk_queue_max_segments(mq->queue, host->max_segs);
336 blk_queue_max_segment_size(mq->queue, host->max_seg_size);
337
338 ret = mmc_queue_alloc_sgs(mq, host->max_segs);
339 if (ret)
340 goto cleanup_queue;
341 }
342
343 sema_init(&mq->thread_sem, 1);
344
345 mq->thread = kthread_run(mmc_queue_thread, mq, "mmcqd/%d%s",
346 host->index, subname ? subname : "");
347
348 if (IS_ERR(mq->thread)) {
349 ret = PTR_ERR(mq->thread);
350 goto cleanup_queue;
351 }
352
353 return 0;
354
355 cleanup_queue:
356 mmc_queue_reqs_free_bufs(mq);
357 kfree(mq->mqrq);
358 mq->mqrq = NULL;
359blk_cleanup:
360 blk_cleanup_queue(mq->queue);
361 return ret;
362}
363
364void mmc_cleanup_queue(struct mmc_queue *mq)
365{
366 struct request_queue *q = mq->queue;
367 unsigned long flags;
368
369 /* Make sure the queue isn't suspended, as that will deadlock */
370 mmc_queue_resume(mq);
371
372 /* Then terminate our worker thread */
373 kthread_stop(mq->thread);
374
375 /* Empty the queue */
376 spin_lock_irqsave(q->queue_lock, flags);
377 q->queuedata = NULL;
378 blk_start_queue(q);
379 spin_unlock_irqrestore(q->queue_lock, flags);
380
381 mmc_queue_reqs_free_bufs(mq);
382 kfree(mq->mqrq);
383 mq->mqrq = NULL;
384
385 mq->card = NULL;
386}
387EXPORT_SYMBOL(mmc_cleanup_queue);
388
389/**
390 * mmc_queue_suspend - suspend a MMC request queue
391 * @mq: MMC queue to suspend
392 *
393 * Stop the block request queue, and wait for our thread to
394 * complete any outstanding requests. This ensures that we
395 * won't suspend while a request is being processed.
396 */
397void mmc_queue_suspend(struct mmc_queue *mq)
398{
399 struct request_queue *q = mq->queue;
400 unsigned long flags;
401
402 if (!(mq->flags & MMC_QUEUE_SUSPENDED)) {
403 mq->flags |= MMC_QUEUE_SUSPENDED;
404
405 spin_lock_irqsave(q->queue_lock, flags);
406 blk_stop_queue(q);
407 spin_unlock_irqrestore(q->queue_lock, flags);
408
409 down(&mq->thread_sem);
410 }
411}
412
413/**
414 * mmc_queue_resume - resume a previously suspended MMC request queue
415 * @mq: MMC queue to resume
416 */
417void mmc_queue_resume(struct mmc_queue *mq)
418{
419 struct request_queue *q = mq->queue;
420 unsigned long flags;
421
422 if (mq->flags & MMC_QUEUE_SUSPENDED) {
423 mq->flags &= ~MMC_QUEUE_SUSPENDED;
424
425 up(&mq->thread_sem);
426
427 spin_lock_irqsave(q->queue_lock, flags);
428 blk_start_queue(q);
429 spin_unlock_irqrestore(q->queue_lock, flags);
430 }
431}
432
433/*
434 * Prepare the sg list(s) to be handed of to the host driver
435 */
436unsigned int mmc_queue_map_sg(struct mmc_queue *mq, struct mmc_queue_req *mqrq)
437{
438 unsigned int sg_len;
439 size_t buflen;
440 struct scatterlist *sg;
441 int i;
442
443 if (!mqrq->bounce_buf)
444 return blk_rq_map_sg(mq->queue, mqrq->req, mqrq->sg);
445
446 sg_len = blk_rq_map_sg(mq->queue, mqrq->req, mqrq->bounce_sg);
447
448 mqrq->bounce_sg_len = sg_len;
449
450 buflen = 0;
451 for_each_sg(mqrq->bounce_sg, sg, sg_len, i)
452 buflen += sg->length;
453
454 sg_init_one(mqrq->sg, mqrq->bounce_buf, buflen);
455
456 return 1;
457}
458
459/*
460 * If writing, bounce the data to the buffer before the request
461 * is sent to the host driver
462 */
463void mmc_queue_bounce_pre(struct mmc_queue_req *mqrq)
464{
465 if (!mqrq->bounce_buf)
466 return;
467
468 if (rq_data_dir(mqrq->req) != WRITE)
469 return;
470
471 sg_copy_to_buffer(mqrq->bounce_sg, mqrq->bounce_sg_len,
472 mqrq->bounce_buf, mqrq->sg[0].length);
473}
474
475/*
476 * If reading, bounce the data from the buffer after the request
477 * has been handled by the host driver
478 */
479void mmc_queue_bounce_post(struct mmc_queue_req *mqrq)
480{
481 if (!mqrq->bounce_buf)
482 return;
483
484 if (rq_data_dir(mqrq->req) != READ)
485 return;
486
487 sg_copy_from_buffer(mqrq->bounce_sg, mqrq->bounce_sg_len,
488 mqrq->bounce_buf, mqrq->sg[0].length);
489}