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/module.h>
13 #include <linux/blkdev.h>
14 #include <linux/freezer.h>
15 #include <linux/kthread.h>
16 #include <linux/scatterlist.h>
18 #include <linux/mmc/card.h>
19 #include <linux/mmc/host.h>
22 #define MMC_QUEUE_BOUNCESZ 65536
24 #define MMC_QUEUE_SUSPENDED (1 << 0)
27 * Prepare a MMC request. This just filters out odd stuff.
29 static int mmc_prep_request(struct request_queue *q, struct request *req)
32 * We only like normal block requests.
34 if (!blk_fs_request(req) && !blk_pc_request(req)) {
35 blk_dump_rq_flags(req, "MMC bad request");
39 req->cmd_flags |= REQ_DONTPREP;
44 static int mmc_queue_thread(void *d)
46 struct mmc_queue *mq = d;
47 struct request_queue *q = mq->queue;
49 current->flags |= PF_MEMALLOC;
51 down(&mq->thread_sem);
53 struct request *req = NULL;
55 spin_lock_irq(q->queue_lock);
56 set_current_state(TASK_INTERRUPTIBLE);
57 if (!blk_queue_plugged(q))
58 req = elv_next_request(q);
60 spin_unlock_irq(q->queue_lock);
63 if (kthread_should_stop()) {
64 set_current_state(TASK_RUNNING);
69 down(&mq->thread_sem);
72 set_current_state(TASK_RUNNING);
74 mq->issue_fn(mq, req);
82 * Generic MMC request handler. This is called for any queue on a
83 * particular host. When the host is not busy, we look for a request
84 * on any queue on this host, and attempt to issue it. This may
85 * not be the queue we were asked to process.
87 static void mmc_request(struct request_queue *q)
89 struct mmc_queue *mq = q->queuedata;
94 printk(KERN_ERR "MMC: killing requests for dead queue\n");
95 while ((req = elv_next_request(q)) != NULL) {
97 ret = __blk_end_request(req, -EIO,
98 blk_rq_cur_bytes(req));
105 wake_up_process(mq->thread);
109 * mmc_init_queue - initialise a queue structure.
111 * @card: mmc card to attach this queue
114 * Initialise a MMC card request queue.
116 int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card, spinlock_t *lock)
118 struct mmc_host *host = card->host;
119 u64 limit = BLK_BOUNCE_HIGH;
122 if (mmc_dev(host)->dma_mask && *mmc_dev(host)->dma_mask)
123 limit = *mmc_dev(host)->dma_mask;
126 mq->queue = blk_init_queue(mmc_request, lock);
130 mq->queue->queuedata = mq;
133 blk_queue_prep_rq(mq->queue, mmc_prep_request);
135 #ifdef CONFIG_MMC_BLOCK_BOUNCE
136 if (host->max_hw_segs == 1) {
137 unsigned int bouncesz;
139 bouncesz = MMC_QUEUE_BOUNCESZ;
141 if (bouncesz > host->max_req_size)
142 bouncesz = host->max_req_size;
143 if (bouncesz > host->max_seg_size)
144 bouncesz = host->max_seg_size;
145 if (bouncesz > (host->max_blk_count * 512))
146 bouncesz = host->max_blk_count * 512;
148 if (bouncesz > 512) {
149 mq->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
150 if (!mq->bounce_buf) {
151 printk(KERN_WARNING "%s: unable to "
152 "allocate bounce buffer\n",
153 mmc_card_name(card));
157 if (mq->bounce_buf) {
158 blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_ANY);
159 blk_queue_max_sectors(mq->queue, bouncesz / 512);
160 blk_queue_max_phys_segments(mq->queue, bouncesz / 512);
161 blk_queue_max_hw_segments(mq->queue, bouncesz / 512);
162 blk_queue_max_segment_size(mq->queue, bouncesz);
164 mq->sg = kmalloc(sizeof(struct scatterlist),
170 sg_init_table(mq->sg, 1);
172 mq->bounce_sg = kmalloc(sizeof(struct scatterlist) *
173 bouncesz / 512, GFP_KERNEL);
174 if (!mq->bounce_sg) {
178 sg_init_table(mq->bounce_sg, bouncesz / 512);
183 if (!mq->bounce_buf) {
184 blk_queue_bounce_limit(mq->queue, limit);
185 blk_queue_max_sectors(mq->queue,
186 min(host->max_blk_count, host->max_req_size / 512));
187 blk_queue_max_phys_segments(mq->queue, host->max_phys_segs);
188 blk_queue_max_hw_segments(mq->queue, host->max_hw_segs);
189 blk_queue_max_segment_size(mq->queue, host->max_seg_size);
191 mq->sg = kmalloc(sizeof(struct scatterlist) *
192 host->max_phys_segs, GFP_KERNEL);
197 sg_init_table(mq->sg, host->max_phys_segs);
200 init_MUTEX(&mq->thread_sem);
202 mq->thread = kthread_run(mmc_queue_thread, mq, "mmcqd");
203 if (IS_ERR(mq->thread)) {
204 ret = PTR_ERR(mq->thread);
211 kfree(mq->bounce_sg);
212 mq->bounce_sg = NULL;
218 kfree(mq->bounce_buf);
219 mq->bounce_buf = NULL;
220 blk_cleanup_queue(mq->queue);
224 void mmc_cleanup_queue(struct mmc_queue *mq)
226 struct request_queue *q = mq->queue;
229 /* Mark that we should start throwing out stragglers */
230 spin_lock_irqsave(q->queue_lock, flags);
232 spin_unlock_irqrestore(q->queue_lock, flags);
234 /* Make sure the queue isn't suspended, as that will deadlock */
235 mmc_queue_resume(mq);
237 /* Then terminate our worker thread */
238 kthread_stop(mq->thread);
241 kfree(mq->bounce_sg);
242 mq->bounce_sg = NULL;
248 kfree(mq->bounce_buf);
249 mq->bounce_buf = NULL;
251 blk_cleanup_queue(mq->queue);
255 EXPORT_SYMBOL(mmc_cleanup_queue);
258 * mmc_queue_suspend - suspend a MMC request queue
259 * @mq: MMC queue to suspend
261 * Stop the block request queue, and wait for our thread to
262 * complete any outstanding requests. This ensures that we
263 * won't suspend while a request is being processed.
265 void mmc_queue_suspend(struct mmc_queue *mq)
267 struct request_queue *q = mq->queue;
270 if (!(mq->flags & MMC_QUEUE_SUSPENDED)) {
271 mq->flags |= MMC_QUEUE_SUSPENDED;
273 spin_lock_irqsave(q->queue_lock, flags);
275 spin_unlock_irqrestore(q->queue_lock, flags);
277 down(&mq->thread_sem);
282 * mmc_queue_resume - resume a previously suspended MMC request queue
283 * @mq: MMC queue to resume
285 void mmc_queue_resume(struct mmc_queue *mq)
287 struct request_queue *q = mq->queue;
290 if (mq->flags & MMC_QUEUE_SUSPENDED) {
291 mq->flags &= ~MMC_QUEUE_SUSPENDED;
295 spin_lock_irqsave(q->queue_lock, flags);
297 spin_unlock_irqrestore(q->queue_lock, flags);
302 * Prepare the sg list(s) to be handed of to the host driver
304 unsigned int mmc_queue_map_sg(struct mmc_queue *mq)
308 struct scatterlist *sg;
312 return blk_rq_map_sg(mq->queue, mq->req, mq->sg);
314 BUG_ON(!mq->bounce_sg);
316 sg_len = blk_rq_map_sg(mq->queue, mq->req, mq->bounce_sg);
318 mq->bounce_sg_len = sg_len;
321 for_each_sg(mq->bounce_sg, sg, sg_len, i)
322 buflen += sg->length;
324 sg_init_one(mq->sg, mq->bounce_buf, buflen);
330 * If writing, bounce the data to the buffer before the request
331 * is sent to the host driver
333 void mmc_queue_bounce_pre(struct mmc_queue *mq)
340 if (rq_data_dir(mq->req) != WRITE)
343 local_irq_save(flags);
344 sg_copy_to_buffer(mq->bounce_sg, mq->bounce_sg_len,
345 mq->bounce_buf, mq->sg[0].length);
346 local_irq_restore(flags);
350 * If reading, bounce the data from the buffer after the request
351 * has been handled by the host driver
353 void mmc_queue_bounce_post(struct mmc_queue *mq)
360 if (rq_data_dir(mq->req) != READ)
363 local_irq_save(flags);
364 sg_copy_from_buffer(mq->bounce_sg, mq->bounce_sg_len,
365 mq->bounce_buf, mq->sg[0].length);
366 local_irq_restore(flags);