linux/drivers/mmc/card/queue.c
Sujit Reddy Thumma a8ad82cc1b mmc: card: Kill block requests if card is removed
Kill block requests when the host realizes that the card is
removed from the slot and is sure that subsequent requests
are bound to fail. Do this silently so that the block
layer doesn't output unnecessary error messages.

Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-01-11 23:58:44 -05:00

439 lines
10 KiB
C

/*
* 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)
{
struct mmc_queue *mq = q->queuedata;
/*
* 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;
}
if (mq && mmc_card_removed(mq->card))
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;
struct mmc_queue_req *tmp;
spin_lock_irq(q->queue_lock);
set_current_state(TASK_INTERRUPTIBLE);
req = blk_fetch_request(q);
mq->mqrq_cur->req = req;
spin_unlock_irq(q->queue_lock);
if (req || mq->mqrq_prev->req) {
set_current_state(TASK_RUNNING);
mq->issue_fn(mq, req);
} else {
if (kthread_should_stop()) {
set_current_state(TASK_RUNNING);
break;
}
up(&mq->thread_sem);
schedule();
down(&mq->thread_sem);
}
/* Current request becomes previous request and vice versa. */
mq->mqrq_prev->brq.mrq.data = NULL;
mq->mqrq_prev->req = NULL;
tmp = mq->mqrq_prev;
mq->mqrq_prev = mq->mqrq_cur;
mq->mqrq_cur = tmp;
} 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->mqrq_cur->req && !mq->mqrq_prev->req)
wake_up_process(mq->thread);
}
static struct scatterlist *mmc_alloc_sg(int sg_len, int *err)
{
struct scatterlist *sg;
sg = kmalloc(sizeof(struct scatterlist)*sg_len, GFP_KERNEL);
if (!sg)
*err = -ENOMEM;
else {
*err = 0;
sg_init_table(sg, sg_len);
}
return sg;
}
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) || mmc_can_sanitize(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;
struct mmc_queue_req *mqrq_cur = &mq->mqrq[0];
struct mmc_queue_req *mqrq_prev = &mq->mqrq[1];
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;
memset(&mq->mqrq_cur, 0, sizeof(mq->mqrq_cur));
memset(&mq->mqrq_prev, 0, sizeof(mq->mqrq_prev));
mq->mqrq_cur = mqrq_cur;
mq->mqrq_prev = mqrq_prev;
mq->queue->queuedata = mq;
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) {
mqrq_cur->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
if (!mqrq_cur->bounce_buf) {
pr_warning("%s: unable to "
"allocate bounce cur buffer\n",
mmc_card_name(card));
}
mqrq_prev->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
if (!mqrq_prev->bounce_buf) {
pr_warning("%s: unable to "
"allocate bounce prev buffer\n",
mmc_card_name(card));
kfree(mqrq_cur->bounce_buf);
mqrq_cur->bounce_buf = NULL;
}
}
if (mqrq_cur->bounce_buf && mqrq_prev->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);
mqrq_cur->sg = mmc_alloc_sg(1, &ret);
if (ret)
goto cleanup_queue;
mqrq_cur->bounce_sg =
mmc_alloc_sg(bouncesz / 512, &ret);
if (ret)
goto cleanup_queue;
mqrq_prev->sg = mmc_alloc_sg(1, &ret);
if (ret)
goto cleanup_queue;
mqrq_prev->bounce_sg =
mmc_alloc_sg(bouncesz / 512, &ret);
if (ret)
goto cleanup_queue;
}
}
#endif
if (!mqrq_cur->bounce_buf && !mqrq_prev->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);
mqrq_cur->sg = mmc_alloc_sg(host->max_segs, &ret);
if (ret)
goto cleanup_queue;
mqrq_prev->sg = mmc_alloc_sg(host->max_segs, &ret);
if (ret)
goto cleanup_queue;
}
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:
kfree(mqrq_cur->bounce_sg);
mqrq_cur->bounce_sg = NULL;
kfree(mqrq_prev->bounce_sg);
mqrq_prev->bounce_sg = NULL;
cleanup_queue:
kfree(mqrq_cur->sg);
mqrq_cur->sg = NULL;
kfree(mqrq_cur->bounce_buf);
mqrq_cur->bounce_buf = NULL;
kfree(mqrq_prev->sg);
mqrq_prev->sg = NULL;
kfree(mqrq_prev->bounce_buf);
mqrq_prev->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;
struct mmc_queue_req *mqrq_cur = mq->mqrq_cur;
struct mmc_queue_req *mqrq_prev = mq->mqrq_prev;
/* 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);
kfree(mqrq_cur->bounce_sg);
mqrq_cur->bounce_sg = NULL;
kfree(mqrq_cur->sg);
mqrq_cur->sg = NULL;
kfree(mqrq_cur->bounce_buf);
mqrq_cur->bounce_buf = NULL;
kfree(mqrq_prev->bounce_sg);
mqrq_prev->bounce_sg = NULL;
kfree(mqrq_prev->sg);
mqrq_prev->sg = NULL;
kfree(mqrq_prev->bounce_buf);
mqrq_prev->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, struct mmc_queue_req *mqrq)
{
unsigned int sg_len;
size_t buflen;
struct scatterlist *sg;
int i;
if (!mqrq->bounce_buf)
return blk_rq_map_sg(mq->queue, mqrq->req, mqrq->sg);
BUG_ON(!mqrq->bounce_sg);
sg_len = blk_rq_map_sg(mq->queue, mqrq->req, mqrq->bounce_sg);
mqrq->bounce_sg_len = sg_len;
buflen = 0;
for_each_sg(mqrq->bounce_sg, sg, sg_len, i)
buflen += sg->length;
sg_init_one(mqrq->sg, mqrq->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_req *mqrq)
{
if (!mqrq->bounce_buf)
return;
if (rq_data_dir(mqrq->req) != WRITE)
return;
sg_copy_to_buffer(mqrq->bounce_sg, mqrq->bounce_sg_len,
mqrq->bounce_buf, mqrq->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_req *mqrq)
{
if (!mqrq->bounce_buf)
return;
if (rq_data_dir(mqrq->req) != READ)
return;
sg_copy_from_buffer(mqrq->bounce_sg, mqrq->bounce_sg_len,
mqrq->bounce_buf, mqrq->sg[0].length);
}