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e056a1b5b6
kernel_optimize_test/drivers/mmc/card/queue.c
Adrian Hunter e056a1b5b6 mmc: queue: let host controllers specify maximum discard timeout 
Some host controllers will not operate without a hardware
timeout that is limited in value.  However large discards
require large timeouts, so there needs to be a way to
specify the maximum discard size.

A host controller driver may now specify the maximum discard
timeout possible so that max_discard_sectors can be calculated.

However, for eMMC when the High Capacity Erase Group Size
is not in use, the timeout calculation depends on clock
rate which may change.  For that case Preferred Erase Size
is used instead.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2011-07-20 17:21:03 -04:00

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/*
* 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);
}
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