| /* |
| * linux/drivers/mmc/card/queue.c |
| * |
| * Copyright (C) 2003 Russell King, All Rights Reserved. |
| * Copyright 2006-2007 Pierre Ossman |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| * |
| */ |
| #include <linux/slab.h> |
| #include <linux/module.h> |
| #include <linux/blkdev.h> |
| #include <linux/freezer.h> |
| #include <linux/kthread.h> |
| #include <linux/scatterlist.h> |
| |
| #include <linux/mmc/card.h> |
| #include <linux/mmc/host.h> |
| #include "queue.h" |
| |
| #define MMC_QUEUE_BOUNCESZ 65536 |
| |
| #define MMC_QUEUE_SUSPENDED (1 << 0) |
| |
| /* |
| * Prepare a MMC request. This just filters out odd stuff. |
| */ |
| static int mmc_prep_request(struct request_queue *q, struct request *req) |
| { |
| /* |
| * We only like normal block requests and discards. |
| */ |
| if (req->cmd_type != REQ_TYPE_FS && !(req->cmd_flags & REQ_DISCARD)) { |
| blk_dump_rq_flags(req, "MMC bad request"); |
| return BLKPREP_KILL; |
| } |
| |
| req->cmd_flags |= REQ_DONTPREP; |
| |
| return BLKPREP_OK; |
| } |
| |
| static int mmc_queue_thread(void *d) |
| { |
| struct mmc_queue *mq = d; |
| struct request_queue *q = mq->queue; |
| |
| current->flags |= PF_MEMALLOC; |
| |
| down(&mq->thread_sem); |
| do { |
| struct request *req = NULL; |
| |
| spin_lock_irq(q->queue_lock); |
| set_current_state(TASK_INTERRUPTIBLE); |
| req = blk_fetch_request(q); |
| mq->req = req; |
| spin_unlock_irq(q->queue_lock); |
| |
| if (!req) { |
| if (kthread_should_stop()) { |
| set_current_state(TASK_RUNNING); |
| break; |
| } |
| up(&mq->thread_sem); |
| schedule(); |
| down(&mq->thread_sem); |
| continue; |
| } |
| set_current_state(TASK_RUNNING); |
| |
| mq->issue_fn(mq, req); |
| } while (1); |
| up(&mq->thread_sem); |
| |
| return 0; |
| } |
| |
| /* |
| * Generic MMC request handler. This is called for any queue on a |
| * particular host. When the host is not busy, we look for a request |
| * on any queue on this host, and attempt to issue it. This may |
| * not be the queue we were asked to process. |
| */ |
| static void mmc_request(struct request_queue *q) |
| { |
| struct mmc_queue *mq = q->queuedata; |
| struct request *req; |
| |
| if (!mq) { |
| while ((req = blk_fetch_request(q)) != NULL) { |
| req->cmd_flags |= REQ_QUIET; |
| __blk_end_request_all(req, -EIO); |
| } |
| return; |
| } |
| |
| if (!mq->req) |
| wake_up_process(mq->thread); |
| } |
| |
| static void mmc_queue_setup_discard(struct request_queue *q, |
| struct mmc_card *card) |
| { |
| unsigned max_discard; |
| |
| max_discard = mmc_calc_max_discard(card); |
| if (!max_discard) |
| return; |
| |
| queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q); |
| q->limits.max_discard_sectors = max_discard; |
| if (card->erased_byte == 0) |
| q->limits.discard_zeroes_data = 1; |
| q->limits.discard_granularity = card->pref_erase << 9; |
| /* granularity must not be greater than max. discard */ |
| if (card->pref_erase > max_discard) |
| q->limits.discard_granularity = 0; |
| if (mmc_can_secure_erase_trim(card)) |
| queue_flag_set_unlocked(QUEUE_FLAG_SECDISCARD, q); |
| } |
| |
| /** |
| * mmc_init_queue - initialise a queue structure. |
| * @mq: mmc queue |
| * @card: mmc card to attach this queue |
| * @lock: queue lock |
| * @subname: partition subname |
| * |
| * Initialise a MMC card request queue. |
| */ |
| int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card, |
| spinlock_t *lock, const char *subname) |
| { |
| struct mmc_host *host = card->host; |
| u64 limit = BLK_BOUNCE_HIGH; |
| int ret; |
| |
| if (mmc_dev(host)->dma_mask && *mmc_dev(host)->dma_mask) |
| limit = *mmc_dev(host)->dma_mask; |
| |
| mq->card = card; |
| mq->queue = blk_init_queue(mmc_request, lock); |
| if (!mq->queue) |
| return -ENOMEM; |
| |
| mq->queue->queuedata = mq; |
| mq->req = NULL; |
| |
| blk_queue_prep_rq(mq->queue, mmc_prep_request); |
| queue_flag_set_unlocked(QUEUE_FLAG_NONROT, mq->queue); |
| if (mmc_can_erase(card)) |
| mmc_queue_setup_discard(mq->queue, card); |
| |
| #ifdef CONFIG_MMC_BLOCK_BOUNCE |
| if (host->max_segs == 1) { |
| unsigned int bouncesz; |
| |
| bouncesz = MMC_QUEUE_BOUNCESZ; |
| |
| if (bouncesz > host->max_req_size) |
| bouncesz = host->max_req_size; |
| if (bouncesz > host->max_seg_size) |
| bouncesz = host->max_seg_size; |
| if (bouncesz > (host->max_blk_count * 512)) |
| bouncesz = host->max_blk_count * 512; |
| |
| if (bouncesz > 512) { |
| mq->bounce_buf = kmalloc(bouncesz, GFP_KERNEL); |
| if (!mq->bounce_buf) { |
| printk(KERN_WARNING "%s: unable to " |
| "allocate bounce buffer\n", |
| mmc_card_name(card)); |
| } |
| } |
| |
| if (mq->bounce_buf) { |
| blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_ANY); |
| blk_queue_max_hw_sectors(mq->queue, bouncesz / 512); |
| blk_queue_max_segments(mq->queue, bouncesz / 512); |
| blk_queue_max_segment_size(mq->queue, bouncesz); |
| |
| mq->sg = kmalloc(sizeof(struct scatterlist), |
| GFP_KERNEL); |
| if (!mq->sg) { |
| ret = -ENOMEM; |
| goto cleanup_queue; |
| } |
| sg_init_table(mq->sg, 1); |
| |
| mq->bounce_sg = kmalloc(sizeof(struct scatterlist) * |
| bouncesz / 512, GFP_KERNEL); |
| if (!mq->bounce_sg) { |
| ret = -ENOMEM; |
| goto cleanup_queue; |
| } |
| sg_init_table(mq->bounce_sg, bouncesz / 512); |
| } |
| } |
| #endif |
| |
| if (!mq->bounce_buf) { |
| blk_queue_bounce_limit(mq->queue, limit); |
| blk_queue_max_hw_sectors(mq->queue, |
| min(host->max_blk_count, host->max_req_size / 512)); |
| blk_queue_max_segments(mq->queue, host->max_segs); |
| blk_queue_max_segment_size(mq->queue, host->max_seg_size); |
| |
| mq->sg = kmalloc(sizeof(struct scatterlist) * |
| host->max_segs, GFP_KERNEL); |
| if (!mq->sg) { |
| ret = -ENOMEM; |
| goto cleanup_queue; |
| } |
| sg_init_table(mq->sg, host->max_segs); |
| } |
| |
| sema_init(&mq->thread_sem, 1); |
| |
| mq->thread = kthread_run(mmc_queue_thread, mq, "mmcqd/%d%s", |
| host->index, subname ? subname : ""); |
| |
| if (IS_ERR(mq->thread)) { |
| ret = PTR_ERR(mq->thread); |
| goto free_bounce_sg; |
| } |
| |
| return 0; |
| free_bounce_sg: |
| if (mq->bounce_sg) |
| kfree(mq->bounce_sg); |
| mq->bounce_sg = NULL; |
| cleanup_queue: |
| if (mq->sg) |
| kfree(mq->sg); |
| mq->sg = NULL; |
| if (mq->bounce_buf) |
| kfree(mq->bounce_buf); |
| mq->bounce_buf = NULL; |
| blk_cleanup_queue(mq->queue); |
| return ret; |
| } |
| |
| void mmc_cleanup_queue(struct mmc_queue *mq) |
| { |
| struct request_queue *q = mq->queue; |
| unsigned long flags; |
| |
| /* Make sure the queue isn't suspended, as that will deadlock */ |
| mmc_queue_resume(mq); |
| |
| /* Then terminate our worker thread */ |
| kthread_stop(mq->thread); |
| |
| /* Empty the queue */ |
| spin_lock_irqsave(q->queue_lock, flags); |
| q->queuedata = NULL; |
| blk_start_queue(q); |
| spin_unlock_irqrestore(q->queue_lock, flags); |
| |
| if (mq->bounce_sg) |
| kfree(mq->bounce_sg); |
| mq->bounce_sg = NULL; |
| |
| kfree(mq->sg); |
| mq->sg = NULL; |
| |
| if (mq->bounce_buf) |
| kfree(mq->bounce_buf); |
| mq->bounce_buf = NULL; |
| |
| mq->card = NULL; |
| } |
| EXPORT_SYMBOL(mmc_cleanup_queue); |
| |
| /** |
| * mmc_queue_suspend - suspend a MMC request queue |
| * @mq: MMC queue to suspend |
| * |
| * Stop the block request queue, and wait for our thread to |
| * complete any outstanding requests. This ensures that we |
| * won't suspend while a request is being processed. |
| */ |
| void mmc_queue_suspend(struct mmc_queue *mq) |
| { |
| struct request_queue *q = mq->queue; |
| unsigned long flags; |
| |
| if (!(mq->flags & MMC_QUEUE_SUSPENDED)) { |
| mq->flags |= MMC_QUEUE_SUSPENDED; |
| |
| spin_lock_irqsave(q->queue_lock, flags); |
| blk_stop_queue(q); |
| spin_unlock_irqrestore(q->queue_lock, flags); |
| |
| down(&mq->thread_sem); |
| } |
| } |
| |
| /** |
| * mmc_queue_resume - resume a previously suspended MMC request queue |
| * @mq: MMC queue to resume |
| */ |
| void mmc_queue_resume(struct mmc_queue *mq) |
| { |
| struct request_queue *q = mq->queue; |
| unsigned long flags; |
| |
| if (mq->flags & MMC_QUEUE_SUSPENDED) { |
| mq->flags &= ~MMC_QUEUE_SUSPENDED; |
| |
| up(&mq->thread_sem); |
| |
| spin_lock_irqsave(q->queue_lock, flags); |
| blk_start_queue(q); |
| spin_unlock_irqrestore(q->queue_lock, flags); |
| } |
| } |
| |
| /* |
| * Prepare the sg list(s) to be handed of to the host driver |
| */ |
| unsigned int mmc_queue_map_sg(struct mmc_queue *mq) |
| { |
| unsigned int sg_len; |
| size_t buflen; |
| struct scatterlist *sg; |
| int i; |
| |
| if (!mq->bounce_buf) |
| return blk_rq_map_sg(mq->queue, mq->req, mq->sg); |
| |
| BUG_ON(!mq->bounce_sg); |
| |
| sg_len = blk_rq_map_sg(mq->queue, mq->req, mq->bounce_sg); |
| |
| mq->bounce_sg_len = sg_len; |
| |
| buflen = 0; |
| for_each_sg(mq->bounce_sg, sg, sg_len, i) |
| buflen += sg->length; |
| |
| sg_init_one(mq->sg, mq->bounce_buf, buflen); |
| |
| return 1; |
| } |
| |
| /* |
| * If writing, bounce the data to the buffer before the request |
| * is sent to the host driver |
| */ |
| void mmc_queue_bounce_pre(struct mmc_queue *mq) |
| { |
| if (!mq->bounce_buf) |
| return; |
| |
| if (rq_data_dir(mq->req) != WRITE) |
| return; |
| |
| sg_copy_to_buffer(mq->bounce_sg, mq->bounce_sg_len, |
| mq->bounce_buf, mq->sg[0].length); |
| } |
| |
| /* |
| * If reading, bounce the data from the buffer after the request |
| * has been handled by the host driver |
| */ |
| void mmc_queue_bounce_post(struct mmc_queue *mq) |
| { |
| if (!mq->bounce_buf) |
| return; |
| |
| if (rq_data_dir(mq->req) != READ) |
| return; |
| |
| sg_copy_from_buffer(mq->bounce_sg, mq->bounce_sg_len, |
| mq->bounce_buf, mq->sg[0].length); |
| } |
| |