2 * linux/drivers/mmc/card/queue.c
4 * Copyright (C) 2003 Russell King, All Rights Reserved.
5 * Copyright 2006-2007 Pierre Ossman
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.
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>
19 #include <linux/mmc/card.h>
20 #include <linux/mmc/host.h>
23 #define MMC_QUEUE_BOUNCESZ 65536
25 #define MMC_QUEUE_SUSPENDED (1 << 0)
28 * Prepare a MMC request. This just filters out odd stuff.
30 static int mmc_prep_request(struct request_queue *q, struct request *req)
33 * We only like normal block requests and discards.
35 if (req->cmd_type != REQ_TYPE_FS && !(req->cmd_flags & REQ_DISCARD)) {
36 blk_dump_rq_flags(req, "MMC bad request");
40 req->cmd_flags |= REQ_DONTPREP;
45 static int mmc_queue_thread(void *d)
47 struct mmc_queue *mq = d;
48 struct request_queue *q = mq->queue;
50 current->flags |= PF_MEMALLOC;
52 down(&mq->thread_sem);
54 struct request *req = NULL;
56 spin_lock_irq(q->queue_lock);
57 set_current_state(TASK_INTERRUPTIBLE);
58 if (!blk_queue_plugged(q))
59 req = blk_fetch_request(q);
61 spin_unlock_irq(q->queue_lock);
64 if (kthread_should_stop()) {
65 set_current_state(TASK_RUNNING);
70 down(&mq->thread_sem);
73 set_current_state(TASK_RUNNING);
75 mq->issue_fn(mq, req);
83 * Generic MMC request handler. This is called for any queue on a
84 * particular host. When the host is not busy, we look for a request
85 * on any queue on this host, and attempt to issue it. This may
86 * not be the queue we were asked to process.
88 static void mmc_request(struct request_queue *q)
90 struct mmc_queue *mq = q->queuedata;
94 while ((req = blk_fetch_request(q)) != NULL) {
95 req->cmd_flags |= REQ_QUIET;
96 __blk_end_request_all(req, -EIO);
102 wake_up_process(mq->thread);
106 * mmc_init_queue - initialise a queue structure.
108 * @card: mmc card to attach this queue
111 * Initialise a MMC card request queue.
113 int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card, spinlock_t *lock)
115 struct mmc_host *host = card->host;
116 u64 limit = BLK_BOUNCE_HIGH;
119 if (mmc_dev(host)->dma_mask && *mmc_dev(host)->dma_mask)
120 limit = *mmc_dev(host)->dma_mask;
123 mq->queue = blk_init_queue(mmc_request, lock);
127 mq->queue->queuedata = mq;
130 blk_queue_prep_rq(mq->queue, mmc_prep_request);
131 queue_flag_set_unlocked(QUEUE_FLAG_NONROT, mq->queue);
132 if (mmc_can_erase(card)) {
133 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mq->queue);
134 mq->queue->limits.max_discard_sectors = UINT_MAX;
135 if (card->erased_byte == 0)
136 mq->queue->limits.discard_zeroes_data = 1;
137 if (!mmc_can_trim(card) && is_power_of_2(card->erase_size)) {
138 mq->queue->limits.discard_granularity =
139 card->erase_size << 9;
140 mq->queue->limits.discard_alignment =
141 card->erase_size << 9;
143 if (mmc_can_secure_erase_trim(card))
144 queue_flag_set_unlocked(QUEUE_FLAG_SECDISCARD,
148 #ifdef CONFIG_MMC_BLOCK_BOUNCE
149 if (host->max_hw_segs == 1) {
150 unsigned int bouncesz;
152 bouncesz = MMC_QUEUE_BOUNCESZ;
154 if (bouncesz > host->max_req_size)
155 bouncesz = host->max_req_size;
156 if (bouncesz > host->max_seg_size)
157 bouncesz = host->max_seg_size;
158 if (bouncesz > (host->max_blk_count * 512))
159 bouncesz = host->max_blk_count * 512;
161 if (bouncesz > 512) {
162 mq->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
163 if (!mq->bounce_buf) {
164 printk(KERN_WARNING "%s: unable to "
165 "allocate bounce buffer\n",
166 mmc_card_name(card));
170 if (mq->bounce_buf) {
171 blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_ANY);
172 blk_queue_max_hw_sectors(mq->queue, bouncesz / 512);
173 blk_queue_max_segments(mq->queue, bouncesz / 512);
174 blk_queue_max_segment_size(mq->queue, bouncesz);
176 mq->sg = kmalloc(sizeof(struct scatterlist),
182 sg_init_table(mq->sg, 1);
184 mq->bounce_sg = kmalloc(sizeof(struct scatterlist) *
185 bouncesz / 512, GFP_KERNEL);
186 if (!mq->bounce_sg) {
190 sg_init_table(mq->bounce_sg, bouncesz / 512);
195 if (!mq->bounce_buf) {
196 blk_queue_bounce_limit(mq->queue, limit);
197 blk_queue_max_hw_sectors(mq->queue,
198 min(host->max_blk_count, host->max_req_size / 512));
199 blk_queue_max_segments(mq->queue, host->max_hw_segs);
200 blk_queue_max_segment_size(mq->queue, host->max_seg_size);
202 mq->sg = kmalloc(sizeof(struct scatterlist) *
203 host->max_phys_segs, GFP_KERNEL);
208 sg_init_table(mq->sg, host->max_phys_segs);
211 init_MUTEX(&mq->thread_sem);
213 mq->thread = kthread_run(mmc_queue_thread, mq, "mmcqd");
214 if (IS_ERR(mq->thread)) {
215 ret = PTR_ERR(mq->thread);
222 kfree(mq->bounce_sg);
223 mq->bounce_sg = NULL;
229 kfree(mq->bounce_buf);
230 mq->bounce_buf = NULL;
231 blk_cleanup_queue(mq->queue);
235 void mmc_cleanup_queue(struct mmc_queue *mq)
237 struct request_queue *q = mq->queue;
240 /* Make sure the queue isn't suspended, as that will deadlock */
241 mmc_queue_resume(mq);
243 /* Then terminate our worker thread */
244 kthread_stop(mq->thread);
246 /* Empty the queue */
247 spin_lock_irqsave(q->queue_lock, flags);
250 spin_unlock_irqrestore(q->queue_lock, flags);
253 kfree(mq->bounce_sg);
254 mq->bounce_sg = NULL;
260 kfree(mq->bounce_buf);
261 mq->bounce_buf = NULL;
265 EXPORT_SYMBOL(mmc_cleanup_queue);
268 * mmc_queue_suspend - suspend a MMC request queue
269 * @mq: MMC queue to suspend
271 * Stop the block request queue, and wait for our thread to
272 * complete any outstanding requests. This ensures that we
273 * won't suspend while a request is being processed.
275 void mmc_queue_suspend(struct mmc_queue *mq)
277 struct request_queue *q = mq->queue;
280 if (!(mq->flags & MMC_QUEUE_SUSPENDED)) {
281 mq->flags |= MMC_QUEUE_SUSPENDED;
283 spin_lock_irqsave(q->queue_lock, flags);
285 spin_unlock_irqrestore(q->queue_lock, flags);
287 down(&mq->thread_sem);
292 * mmc_queue_resume - resume a previously suspended MMC request queue
293 * @mq: MMC queue to resume
295 void mmc_queue_resume(struct mmc_queue *mq)
297 struct request_queue *q = mq->queue;
300 if (mq->flags & MMC_QUEUE_SUSPENDED) {
301 mq->flags &= ~MMC_QUEUE_SUSPENDED;
305 spin_lock_irqsave(q->queue_lock, flags);
307 spin_unlock_irqrestore(q->queue_lock, flags);
312 * Prepare the sg list(s) to be handed of to the host driver
314 unsigned int mmc_queue_map_sg(struct mmc_queue *mq)
318 struct scatterlist *sg;
322 return blk_rq_map_sg(mq->queue, mq->req, mq->sg);
324 BUG_ON(!mq->bounce_sg);
326 sg_len = blk_rq_map_sg(mq->queue, mq->req, mq->bounce_sg);
328 mq->bounce_sg_len = sg_len;
331 for_each_sg(mq->bounce_sg, sg, sg_len, i)
332 buflen += sg->length;
334 sg_init_one(mq->sg, mq->bounce_buf, buflen);
340 * If writing, bounce the data to the buffer before the request
341 * is sent to the host driver
343 void mmc_queue_bounce_pre(struct mmc_queue *mq)
350 if (rq_data_dir(mq->req) != WRITE)
353 local_irq_save(flags);
354 sg_copy_to_buffer(mq->bounce_sg, mq->bounce_sg_len,
355 mq->bounce_buf, mq->sg[0].length);
356 local_irq_restore(flags);
360 * If reading, bounce the data from the buffer after the request
361 * has been handled by the host driver
363 void mmc_queue_bounce_post(struct mmc_queue *mq)
370 if (rq_data_dir(mq->req) != READ)
373 local_irq_save(flags);
374 sg_copy_from_buffer(mq->bounce_sg, mq->bounce_sg_len,
375 mq->bounce_buf, mq->sg[0].length);
376 local_irq_restore(flags);