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switch-linux/drivers/mmc/core/queue.c
Christoph Hellwig 2a842acab1 block: introduce new block status code type 
Currently we use nornal Linux errno values in the block layer, and while
we accept any error a few have overloaded magic meanings.  This patch
instead introduces a new  blk_status_t value that holds block layer specific
status codes and explicitly explains their meaning.  Helpers to convert from
and to the previous special meanings are provided for now, but I suspect
we want to get rid of them in the long run - those drivers that have a
errno input (e.g. networking) usually get errnos that don't know about
the special block layer overloads, and similarly returning them to userspace
will usually return somethings that strictly speaking isn't correct
for file system operations, but that's left as an exercise for later.

For now the set of errors is a very limited set that closely corresponds
to the previous overloaded errno values, but there is some low hanging
fruite to improve it.

blk_status_t (ab)uses the sparse __bitwise annotations to allow for sparse
typechecking, so that we can easily catch places passing the wrong values.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-06-09 09:27:32 -06:00

543 lines
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/*
* 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/dma-mapping.h>
#include <linux/mmc/card.h>
#include <linux/mmc/host.h>
#include "queue.h"
#include "block.h"
#include "core.h"
#include "card.h"
#define MMC_QUEUE_BOUNCESZ 65536
/*
* 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;
if (mq && (mmc_card_removed(mq->card) || mmc_access_rpmb(mq)))
return BLKPREP_KILL;
req->rq_flags |= RQF_DONTPREP;
return BLKPREP_OK;
}
struct mmc_queue_req *mmc_queue_req_find(struct mmc_queue *mq,
struct request *req)
{
struct mmc_queue_req *mqrq;
int i = ffz(mq->qslots);
if (i >= mq->qdepth)
return NULL;
mqrq = &mq->mqrq[i];
WARN_ON(mqrq->req || mq->qcnt >= mq->qdepth ||
test_bit(mqrq->task_id, &mq->qslots));
mqrq->req = req;
mq->qcnt += 1;
__set_bit(mqrq->task_id, &mq->qslots);
return mqrq;
}
void mmc_queue_req_free(struct mmc_queue *mq,
struct mmc_queue_req *mqrq)
{
WARN_ON(!mqrq->req || mq->qcnt < 1 ||
!test_bit(mqrq->task_id, &mq->qslots));
mqrq->req = NULL;
mq->qcnt -= 1;
__clear_bit(mqrq->task_id, &mq->qslots);
}
static int mmc_queue_thread(void *d)
{
struct mmc_queue *mq = d;
struct request_queue *q = mq->queue;
struct mmc_context_info *cntx = &mq->card->host->context_info;
current->flags |= PF_MEMALLOC;
down(&mq->thread_sem);
do {
struct request *req;
spin_lock_irq(q->queue_lock);
set_current_state(TASK_INTERRUPTIBLE);
req = blk_fetch_request(q);
mq->asleep = false;
cntx->is_waiting_last_req = false;
cntx->is_new_req = false;
if (!req) {
/*
* Dispatch queue is empty so set flags for
* mmc_request_fn() to wake us up.
*/
if (mq->qcnt)
cntx->is_waiting_last_req = true;
else
mq->asleep = true;
}
spin_unlock_irq(q->queue_lock);
if (req || mq->qcnt) {
set_current_state(TASK_RUNNING);
mmc_blk_issue_rq(mq, req);
cond_resched();
} else {
if (kthread_should_stop()) {
set_current_state(TASK_RUNNING);
break;
}
up(&mq->thread_sem);
schedule();
down(&mq->thread_sem);
}
} 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_fn(struct request_queue *q)
{
struct mmc_queue *mq = q->queuedata;
struct request *req;
struct mmc_context_info *cntx;
if (!mq) {
while ((req = blk_fetch_request(q)) != NULL) {
req->rq_flags |= RQF_QUIET;
__blk_end_request_all(req, BLK_STS_IOERR);
}
return;
}
cntx = &mq->card->host->context_info;
if (cntx->is_waiting_last_req) {
cntx->is_new_req = true;
wake_up_interruptible(&cntx->wait);
}
if (mq->asleep)
wake_up_process(mq->thread);
}
static struct scatterlist *mmc_alloc_sg(int sg_len)
{
struct scatterlist *sg;
sg = kmalloc_array(sg_len, sizeof(*sg), GFP_KERNEL);
if (sg)
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);
blk_queue_max_discard_sectors(q, max_discard);
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_SECERASE, q);
}
static void mmc_queue_req_free_bufs(struct mmc_queue_req *mqrq)
{
kfree(mqrq->bounce_sg);
mqrq->bounce_sg = NULL;
kfree(mqrq->sg);
mqrq->sg = NULL;
kfree(mqrq->bounce_buf);
mqrq->bounce_buf = NULL;
}
static void mmc_queue_reqs_free_bufs(struct mmc_queue_req *mqrq, int qdepth)
{
int i;
for (i = 0; i < qdepth; i++)
mmc_queue_req_free_bufs(&mqrq[i]);
}
static void mmc_queue_free_mqrqs(struct mmc_queue_req *mqrq, int qdepth)
{
mmc_queue_reqs_free_bufs(mqrq, qdepth);
kfree(mqrq);
}
static struct mmc_queue_req *mmc_queue_alloc_mqrqs(int qdepth)
{
struct mmc_queue_req *mqrq;
int i;
mqrq = kcalloc(qdepth, sizeof(*mqrq), GFP_KERNEL);
if (mqrq) {
for (i = 0; i < qdepth; i++)
mqrq[i].task_id = i;
}
return mqrq;
}
#ifdef CONFIG_MMC_BLOCK_BOUNCE
static int mmc_queue_alloc_bounce_bufs(struct mmc_queue_req *mqrq, int qdepth,
unsigned int bouncesz)
{
int i;
for (i = 0; i < qdepth; i++) {
mqrq[i].bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
if (!mqrq[i].bounce_buf)
return -ENOMEM;
mqrq[i].sg = mmc_alloc_sg(1);
if (!mqrq[i].sg)
return -ENOMEM;
mqrq[i].bounce_sg = mmc_alloc_sg(bouncesz / 512);
if (!mqrq[i].bounce_sg)
return -ENOMEM;
}
return 0;
}
static bool mmc_queue_alloc_bounce(struct mmc_queue_req *mqrq, int qdepth,
unsigned int bouncesz)
{
int ret;
ret = mmc_queue_alloc_bounce_bufs(mqrq, qdepth, bouncesz);
if (ret)
mmc_queue_reqs_free_bufs(mqrq, qdepth);
return !ret;
}
static unsigned int mmc_queue_calc_bouncesz(struct mmc_host *host)
{
unsigned int bouncesz = MMC_QUEUE_BOUNCESZ;
if (host->max_segs != 1)
return 0;
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)
return 0;
return bouncesz;
}
#else
static inline bool mmc_queue_alloc_bounce(struct mmc_queue_req *mqrq,
int qdepth, unsigned int bouncesz)
{
return false;
}
static unsigned int mmc_queue_calc_bouncesz(struct mmc_host *host)
{
return 0;
}
#endif
static int mmc_queue_alloc_sgs(struct mmc_queue_req *mqrq, int qdepth,
int max_segs)
{
int i;
for (i = 0; i < qdepth; i++) {
mqrq[i].sg = mmc_alloc_sg(max_segs);
if (!mqrq[i].sg)
return -ENOMEM;
}
return 0;
}
void mmc_queue_free_shared_queue(struct mmc_card *card)
{
if (card->mqrq) {
mmc_queue_free_mqrqs(card->mqrq, card->qdepth);
card->mqrq = NULL;
}
}
static int __mmc_queue_alloc_shared_queue(struct mmc_card *card, int qdepth)
{
struct mmc_host *host = card->host;
struct mmc_queue_req *mqrq;
unsigned int bouncesz;
int ret = 0;
if (card->mqrq)
return -EINVAL;
mqrq = mmc_queue_alloc_mqrqs(qdepth);
if (!mqrq)
return -ENOMEM;
card->mqrq = mqrq;
card->qdepth = qdepth;
bouncesz = mmc_queue_calc_bouncesz(host);
if (bouncesz && !mmc_queue_alloc_bounce(mqrq, qdepth, bouncesz)) {
bouncesz = 0;
pr_warn("%s: unable to allocate bounce buffers\n",
mmc_card_name(card));
}
card->bouncesz = bouncesz;
if (!bouncesz) {
ret = mmc_queue_alloc_sgs(mqrq, qdepth, host->max_segs);
if (ret)
goto out_err;
}
return ret;
out_err:
mmc_queue_free_shared_queue(card);
return ret;
}
int mmc_queue_alloc_shared_queue(struct mmc_card *card)
{
return __mmc_queue_alloc_shared_queue(card, 2);
}
/**
* 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 = -ENOMEM;
if (mmc_dev(host)->dma_mask && *mmc_dev(host)->dma_mask)
limit = (u64)dma_max_pfn(mmc_dev(host)) << PAGE_SHIFT;
mq->card = card;
mq->queue = blk_init_queue(mmc_request_fn, lock);
if (!mq->queue)
return -ENOMEM;
mq->mqrq = card->mqrq;
mq->qdepth = card->qdepth;
mq->queue->queuedata = mq;
blk_queue_prep_rq(mq->queue, mmc_prep_request);
queue_flag_set_unlocked(QUEUE_FLAG_NONROT, mq->queue);
queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, mq->queue);
if (mmc_can_erase(card))
mmc_queue_setup_discard(mq->queue, card);
if (card->bouncesz) {
blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_ANY);
blk_queue_max_hw_sectors(mq->queue, card->bouncesz / 512);
blk_queue_max_segments(mq->queue, card->bouncesz / 512);
blk_queue_max_segment_size(mq->queue, card->bouncesz);
} else {
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);
}
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 cleanup_queue;
}
return 0;
cleanup_queue:
mq->mqrq = 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);
mq->mqrq = 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->suspended) {
mq->suspended |= true;
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->suspended) {
mq->suspended = false;
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);
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);
}
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