394 строки
8.3 KiB
C
394 строки
8.3 KiB
C
/*
|
|
* linux/drivers/mmc/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/module.h>
|
|
#include <linux/blkdev.h>
|
|
#include <linux/freezer.h>
|
|
#include <linux/kthread.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.
|
|
*/
|
|
if (!blk_fs_request(req) && !blk_pc_request(req)) {
|
|
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);
|
|
if (!blk_queue_plugged(q))
|
|
req = elv_next_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(request_queue_t *q)
|
|
{
|
|
struct mmc_queue *mq = q->queuedata;
|
|
struct request *req;
|
|
int ret;
|
|
|
|
if (!mq) {
|
|
printk(KERN_ERR "MMC: killing requests for dead queue\n");
|
|
while ((req = elv_next_request(q)) != NULL) {
|
|
do {
|
|
ret = end_that_request_chunk(req, 0,
|
|
req->current_nr_sectors << 9);
|
|
} while (ret);
|
|
}
|
|
return;
|
|
}
|
|
|
|
if (!mq->req)
|
|
wake_up_process(mq->thread);
|
|
}
|
|
|
|
/**
|
|
* mmc_init_queue - initialise a queue structure.
|
|
* @mq: mmc queue
|
|
* @card: mmc card to attach this queue
|
|
* @lock: queue lock
|
|
*
|
|
* Initialise a MMC card request queue.
|
|
*/
|
|
int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card, spinlock_t *lock)
|
|
{
|
|
struct mmc_host *host = card->host;
|
|
u64 limit = BLK_BOUNCE_HIGH;
|
|
int ret;
|
|
unsigned int bouncesz;
|
|
|
|
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);
|
|
|
|
#ifdef CONFIG_MMC_BLOCK_BOUNCE
|
|
if (host->max_hw_segs == 1) {
|
|
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;
|
|
|
|
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));
|
|
} else {
|
|
blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_HIGH);
|
|
blk_queue_max_sectors(mq->queue, bouncesz / 512);
|
|
blk_queue_max_phys_segments(mq->queue, bouncesz / 512);
|
|
blk_queue_max_hw_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 free_bounce_buf;
|
|
}
|
|
|
|
mq->bounce_sg = kmalloc(sizeof(struct scatterlist) *
|
|
bouncesz / 512, GFP_KERNEL);
|
|
if (!mq->bounce_sg) {
|
|
ret = -ENOMEM;
|
|
goto free_sg;
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
if (!mq->bounce_buf) {
|
|
blk_queue_bounce_limit(mq->queue, limit);
|
|
blk_queue_max_sectors(mq->queue, host->max_req_size / 512);
|
|
blk_queue_max_phys_segments(mq->queue, host->max_phys_segs);
|
|
blk_queue_max_hw_segments(mq->queue, host->max_hw_segs);
|
|
blk_queue_max_segment_size(mq->queue, host->max_seg_size);
|
|
|
|
mq->sg = kmalloc(sizeof(struct scatterlist) *
|
|
host->max_phys_segs, GFP_KERNEL);
|
|
if (!mq->sg) {
|
|
ret = -ENOMEM;
|
|
goto cleanup_queue;
|
|
}
|
|
}
|
|
|
|
init_MUTEX(&mq->thread_sem);
|
|
|
|
mq->thread = kthread_run(mmc_queue_thread, mq, "mmcqd");
|
|
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;
|
|
free_sg:
|
|
kfree(mq->sg);
|
|
mq->sg = NULL;
|
|
free_bounce_buf:
|
|
if (mq->bounce_buf)
|
|
kfree(mq->bounce_buf);
|
|
mq->bounce_buf = NULL;
|
|
cleanup_queue:
|
|
blk_cleanup_queue(mq->queue);
|
|
return ret;
|
|
}
|
|
|
|
void mmc_cleanup_queue(struct mmc_queue *mq)
|
|
{
|
|
request_queue_t *q = mq->queue;
|
|
unsigned long flags;
|
|
|
|
/* Mark that we should start throwing out stragglers */
|
|
spin_lock_irqsave(q->queue_lock, flags);
|
|
q->queuedata = NULL;
|
|
spin_unlock_irqrestore(q->queue_lock, 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);
|
|
|
|
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;
|
|
|
|
blk_cleanup_queue(mq->queue);
|
|
|
|
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)
|
|
{
|
|
request_queue_t *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)
|
|
{
|
|
request_queue_t *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);
|
|
}
|
|
}
|
|
|
|
static void copy_sg(struct scatterlist *dst, unsigned int dst_len,
|
|
struct scatterlist *src, unsigned int src_len)
|
|
{
|
|
unsigned int chunk;
|
|
char *dst_buf, *src_buf;
|
|
unsigned int dst_size, src_size;
|
|
|
|
dst_buf = NULL;
|
|
src_buf = NULL;
|
|
dst_size = 0;
|
|
src_size = 0;
|
|
|
|
while (src_len) {
|
|
BUG_ON(dst_len == 0);
|
|
|
|
if (dst_size == 0) {
|
|
dst_buf = page_address(dst->page) + dst->offset;
|
|
dst_size = dst->length;
|
|
}
|
|
|
|
if (src_size == 0) {
|
|
src_buf = page_address(src->page) + src->offset;
|
|
src_size = src->length;
|
|
}
|
|
|
|
chunk = min(dst_size, src_size);
|
|
|
|
memcpy(dst_buf, src_buf, chunk);
|
|
|
|
dst_buf += chunk;
|
|
src_buf += chunk;
|
|
dst_size -= chunk;
|
|
src_size -= chunk;
|
|
|
|
if (dst_size == 0) {
|
|
dst++;
|
|
dst_len--;
|
|
}
|
|
|
|
if (src_size == 0) {
|
|
src++;
|
|
src_len--;
|
|
}
|
|
}
|
|
}
|
|
|
|
unsigned int mmc_queue_map_sg(struct mmc_queue *mq)
|
|
{
|
|
unsigned int sg_len;
|
|
|
|
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;
|
|
|
|
/*
|
|
* Shortcut in the event we only get a single entry.
|
|
*/
|
|
if (sg_len == 1) {
|
|
memcpy(mq->sg, mq->bounce_sg, sizeof(struct scatterlist));
|
|
return 1;
|
|
}
|
|
|
|
mq->sg[0].page = virt_to_page(mq->bounce_buf);
|
|
mq->sg[0].offset = offset_in_page(mq->bounce_buf);
|
|
mq->sg[0].length = 0;
|
|
|
|
while (sg_len) {
|
|
mq->sg[0].length += mq->bounce_sg[sg_len - 1].length;
|
|
sg_len--;
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
void mmc_queue_bounce_pre(struct mmc_queue *mq)
|
|
{
|
|
if (!mq->bounce_buf)
|
|
return;
|
|
|
|
if (mq->bounce_sg_len == 1)
|
|
return;
|
|
if (rq_data_dir(mq->req) != WRITE)
|
|
return;
|
|
|
|
copy_sg(mq->sg, 1, mq->bounce_sg, mq->bounce_sg_len);
|
|
}
|
|
|
|
void mmc_queue_bounce_post(struct mmc_queue *mq)
|
|
{
|
|
if (!mq->bounce_buf)
|
|
return;
|
|
|
|
if (mq->bounce_sg_len == 1)
|
|
return;
|
|
if (rq_data_dir(mq->req) != READ)
|
|
return;
|
|
|
|
copy_sg(mq->bounce_sg, mq->bounce_sg_len, mq->sg, 1);
|
|
}
|
|
|