Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
This commit is contained in:
Linus Torvalds
238
drivers/mmc/mmc_queue.c
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238
drivers/mmc/mmc_queue.c
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/*
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* linux/drivers/mmc/mmc_queue.c
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*
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* Copyright (C) 2003 Russell King, All Rights Reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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*/
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#include <linux/module.h>
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#include <linux/blkdev.h>
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#include <linux/mmc/card.h>
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#include <linux/mmc/host.h>
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#include "mmc_queue.h"
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#define MMC_QUEUE_EXIT (1 << 0)
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#define MMC_QUEUE_SUSPENDED (1 << 1)
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/*
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* Prepare a MMC request. Essentially, this means passing the
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* preparation off to the media driver. The media driver will
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* create a mmc_io_request in req->special.
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*/
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static int mmc_prep_request(struct request_queue *q, struct request *req)
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{
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struct mmc_queue *mq = q->queuedata;
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int ret = BLKPREP_KILL;
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if (req->flags & REQ_SPECIAL) {
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/*
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* Special commands already have the command
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* blocks already setup in req->special.
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*/
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BUG_ON(!req->special);
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ret = BLKPREP_OK;
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} else if (req->flags & (REQ_CMD | REQ_BLOCK_PC)) {
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/*
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* Block I/O requests need translating according
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* to the protocol.
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*/
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ret = mq->prep_fn(mq, req);
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} else {
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/*
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* Everything else is invalid.
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*/
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blk_dump_rq_flags(req, "MMC bad request");
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}
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if (ret == BLKPREP_OK)
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req->flags |= REQ_DONTPREP;
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return ret;
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}
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static int mmc_queue_thread(void *d)
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{
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struct mmc_queue *mq = d;
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struct request_queue *q = mq->queue;
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DECLARE_WAITQUEUE(wait, current);
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/*
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* Set iothread to ensure that we aren't put to sleep by
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* the process freezing. We handle suspension ourselves.
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*/
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current->flags |= PF_MEMALLOC|PF_NOFREEZE;
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daemonize("mmcqd");
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complete(&mq->thread_complete);
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down(&mq->thread_sem);
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add_wait_queue(&mq->thread_wq, &wait);
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do {
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struct request *req = NULL;
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spin_lock_irq(q->queue_lock);
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set_current_state(TASK_INTERRUPTIBLE);
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if (!blk_queue_plugged(q))
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mq->req = req = elv_next_request(q);
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spin_unlock_irq(q->queue_lock);
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if (!req) {
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if (mq->flags & MMC_QUEUE_EXIT)
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break;
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up(&mq->thread_sem);
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schedule();
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down(&mq->thread_sem);
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continue;
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}
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set_current_state(TASK_RUNNING);
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mq->issue_fn(mq, req);
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} while (1);
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remove_wait_queue(&mq->thread_wq, &wait);
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up(&mq->thread_sem);
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complete_and_exit(&mq->thread_complete, 0);
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return 0;
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}
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/*
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* Generic MMC request handler. This is called for any queue on a
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* particular host. When the host is not busy, we look for a request
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* on any queue on this host, and attempt to issue it. This may
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* not be the queue we were asked to process.
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*/
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static void mmc_request(request_queue_t *q)
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{
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struct mmc_queue *mq = q->queuedata;
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if (!mq->req)
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wake_up(&mq->thread_wq);
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}
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/**
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* mmc_init_queue - initialise a queue structure.
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* @mq: mmc queue
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* @card: mmc card to attach this queue
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* @lock: queue lock
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*
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* Initialise a MMC card request queue.
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*/
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int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card, spinlock_t *lock)
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{
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struct mmc_host *host = card->host;
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u64 limit = BLK_BOUNCE_HIGH;
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int ret;
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if (host->dev->dma_mask && *host->dev->dma_mask)
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limit = *host->dev->dma_mask;
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mq->card = card;
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mq->queue = blk_init_queue(mmc_request, lock);
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if (!mq->queue)
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return -ENOMEM;
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blk_queue_prep_rq(mq->queue, mmc_prep_request);
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blk_queue_bounce_limit(mq->queue, limit);
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blk_queue_max_sectors(mq->queue, host->max_sectors);
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blk_queue_max_phys_segments(mq->queue, host->max_phys_segs);
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blk_queue_max_hw_segments(mq->queue, host->max_hw_segs);
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blk_queue_max_segment_size(mq->queue, host->max_seg_size);
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mq->queue->queuedata = mq;
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mq->req = NULL;
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mq->sg = kmalloc(sizeof(struct scatterlist) * host->max_phys_segs,
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GFP_KERNEL);
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if (!mq->sg) {
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ret = -ENOMEM;
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goto cleanup;
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}
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init_completion(&mq->thread_complete);
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init_waitqueue_head(&mq->thread_wq);
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init_MUTEX(&mq->thread_sem);
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ret = kernel_thread(mmc_queue_thread, mq, CLONE_KERNEL);
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if (ret >= 0) {
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wait_for_completion(&mq->thread_complete);
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init_completion(&mq->thread_complete);
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ret = 0;
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goto out;
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}
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cleanup:
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kfree(mq->sg);
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mq->sg = NULL;
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blk_cleanup_queue(mq->queue);
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out:
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return ret;
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}
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EXPORT_SYMBOL(mmc_init_queue);
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void mmc_cleanup_queue(struct mmc_queue *mq)
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{
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mq->flags |= MMC_QUEUE_EXIT;
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wake_up(&mq->thread_wq);
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wait_for_completion(&mq->thread_complete);
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kfree(mq->sg);
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mq->sg = NULL;
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blk_cleanup_queue(mq->queue);
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mq->card = NULL;
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}
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EXPORT_SYMBOL(mmc_cleanup_queue);
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/**
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* mmc_queue_suspend - suspend a MMC request queue
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* @mq: MMC queue to suspend
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*
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* Stop the block request queue, and wait for our thread to
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* complete any outstanding requests. This ensures that we
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* won't suspend while a request is being processed.
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*/
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void mmc_queue_suspend(struct mmc_queue *mq)
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{
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request_queue_t *q = mq->queue;
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unsigned long flags;
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if (!(mq->flags & MMC_QUEUE_SUSPENDED)) {
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mq->flags |= MMC_QUEUE_SUSPENDED;
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spin_lock_irqsave(q->queue_lock, flags);
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blk_stop_queue(q);
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spin_unlock_irqrestore(q->queue_lock, flags);
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down(&mq->thread_sem);
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}
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}
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EXPORT_SYMBOL(mmc_queue_suspend);
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/**
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* mmc_queue_resume - resume a previously suspended MMC request queue
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* @mq: MMC queue to resume
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*/
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void mmc_queue_resume(struct mmc_queue *mq)
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{
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request_queue_t *q = mq->queue;
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unsigned long flags;
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if (mq->flags & MMC_QUEUE_SUSPENDED) {
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mq->flags &= ~MMC_QUEUE_SUSPENDED;
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up(&mq->thread_sem);
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spin_lock_irqsave(q->queue_lock, flags);
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blk_start_queue(q);
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spin_unlock_irqrestore(q->queue_lock, flags);
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}
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}
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EXPORT_SYMBOL(mmc_queue_resume);
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