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Commit 6c0cedd1 authored by Adrian Hunter's avatar Adrian Hunter Committed by Ulf Hansson
Browse files

mmc: core: Introduce host claiming by context 



Currently the host can be claimed by a task.  Change this so that the host
can be claimed by a context that may or may not be a task.  This provides
for the host to be claimed by a block driver queue to support blk-mq, while
maintaining compatibility with the existing use of mmc_claim_host().

Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
parent 9ca28c5c

drivers/mmc/core/block.c

+2 −2
Original line number Diff line number Diff line
@@ -1989,7 +1989,7 @@ void mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req) 


	if (req && !mq->qcnt)

		/* claim host only for the first request */

		mmc_get_card(card);

		mmc_get_card(card, NULL);



	ret = mmc_blk_part_switch(card, md->part_type);

	if (ret) {
@@ -2052,7 +2052,7 @@ void mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req) 


out:

	if (!mq->qcnt)

		mmc_put_card(card);

		mmc_put_card(card, NULL);

}



static inline int mmc_blk_readonly(struct mmc_card *card)

drivers/mmc/core/core.c

+41 −7
Original line number Diff line number Diff line
@@ -832,9 +832,36 @@ unsigned int mmc_align_data_size(struct mmc_card *card, unsigned int sz) 
}

EXPORT_SYMBOL(mmc_align_data_size);



/*

 * Allow claiming an already claimed host if the context is the same or there is

 * no context but the task is the same.

 */

static inline bool mmc_ctx_matches(struct mmc_host *host, struct mmc_ctx *ctx,

				   struct task_struct *task)

{

	return host->claimer == ctx ||

	       (!ctx && task && host->claimer->task == task);

}



static inline void mmc_ctx_set_claimer(struct mmc_host *host,

				       struct mmc_ctx *ctx,

				       struct task_struct *task)

{

	if (!host->claimer) {

		if (ctx)

			host->claimer = ctx;

		else

			host->claimer = &host->default_ctx;

	}

	if (task)

		host->claimer->task = task;

}



/**

 *	__mmc_claim_host - exclusively claim a host

 *	@host: mmc host to claim

 *	@ctx: context that claims the host or NULL in which case the default

 *	context will be used

 *	@abort: whether or not the operation should be aborted

 *

 *	Claim a host for a set of operations.  If @abort is non null and
@@ -842,8 +869,10 @@ EXPORT_SYMBOL(mmc_align_data_size); 
 *	that non-zero value without acquiring the lock.  Returns zero

 *	with the lock held otherwise.

 */

int __mmc_claim_host(struct mmc_host *host, atomic_t *abort)

int __mmc_claim_host(struct mmc_host *host, struct mmc_ctx *ctx,

		     atomic_t *abort)

{

	struct task_struct *task = ctx ? NULL : current;

	DECLARE_WAITQUEUE(wait, current);

	unsigned long flags;

	int stop;
@@ -856,7 +885,7 @@ int __mmc_claim_host(struct mmc_host *host, atomic_t *abort) 
	while (1) {

		set_current_state(TASK_UNINTERRUPTIBLE);

		stop = abort ? atomic_read(abort) : 0;

		if (stop || !host->claimed || host->claimer == current)

		if (stop || !host->claimed || mmc_ctx_matches(host, ctx, task))

			break;

		spin_unlock_irqrestore(&host->lock, flags);

		schedule();
@@ -865,7 +894,7 @@ int __mmc_claim_host(struct mmc_host *host, atomic_t *abort) 
	set_current_state(TASK_RUNNING);

	if (!stop) {

		host->claimed = 1;

		host->claimer = current;

		mmc_ctx_set_claimer(host, ctx, task);

		host->claim_cnt += 1;

		if (host->claim_cnt == 1)

			pm = true;
@@ -900,6 +929,7 @@ void mmc_release_host(struct mmc_host *host) 
		spin_unlock_irqrestore(&host->lock, flags);

	} else {

		host->claimed = 0;

		host->claimer->task = NULL;

		host->claimer = NULL;

		spin_unlock_irqrestore(&host->lock, flags);

		wake_up(&host->wq);
@@ -913,10 +943,10 @@ EXPORT_SYMBOL(mmc_release_host); 
 * This is a helper function, which fetches a runtime pm reference for the

 * card device and also claims the host.

 */

void mmc_get_card(struct mmc_card *card)

void mmc_get_card(struct mmc_card *card, struct mmc_ctx *ctx)

{

	pm_runtime_get_sync(&card->dev);

	mmc_claim_host(card->host);

	__mmc_claim_host(card->host, ctx, NULL);

}

EXPORT_SYMBOL(mmc_get_card);
@@ -924,9 +954,13 @@ EXPORT_SYMBOL(mmc_get_card); 
 * This is a helper function, which releases the host and drops the runtime

 * pm reference for the card device.

 */

void mmc_put_card(struct mmc_card *card)

void mmc_put_card(struct mmc_card *card, struct mmc_ctx *ctx)

{

	mmc_release_host(card->host);

	struct mmc_host *host = card->host;



	WARN_ON(ctx && host->claimer != ctx);



	mmc_release_host(host);

	pm_runtime_mark_last_busy(&card->dev);

	pm_runtime_put_autosuspend(&card->dev);

}

drivers/mmc/core/core.h

+5 −4
Original line number Diff line number Diff line
@@ -128,10 +128,11 @@ int mmc_set_blocklen(struct mmc_card *card, unsigned int blocklen); 
int mmc_set_blockcount(struct mmc_card *card, unsigned int blockcount,

			bool is_rel_write);



int __mmc_claim_host(struct mmc_host *host, atomic_t *abort);

int __mmc_claim_host(struct mmc_host *host, struct mmc_ctx *ctx,

		     atomic_t *abort);

void mmc_release_host(struct mmc_host *host);

void mmc_get_card(struct mmc_card *card);

void mmc_put_card(struct mmc_card *card);

void mmc_get_card(struct mmc_card *card, struct mmc_ctx *ctx);

void mmc_put_card(struct mmc_card *card, struct mmc_ctx *ctx);



/**

 *	mmc_claim_host - exclusively claim a host
@@ -141,7 +142,7 @@ void mmc_put_card(struct mmc_card *card); 
 */

static inline void mmc_claim_host(struct mmc_host *host)

{

	__mmc_claim_host(host, NULL);

	__mmc_claim_host(host, NULL, NULL);

}



#endif

drivers/mmc/core/mmc.c

+2 −2
Original line number Diff line number Diff line
@@ -1911,14 +1911,14 @@ static void mmc_detect(struct mmc_host *host) 
{

	int err;



	mmc_get_card(host->card);

	mmc_get_card(host->card, NULL);



	/*

	 * Just check if our card has been removed.

	 */

	err = _mmc_detect_card_removed(host);



	mmc_put_card(host->card);

	mmc_put_card(host->card, NULL);



	if (err) {

		mmc_remove(host);

drivers/mmc/core/sd.c

+2 −2
Original line number Diff line number Diff line
@@ -1056,14 +1056,14 @@ static void mmc_sd_detect(struct mmc_host *host) 
{

	int err;



	mmc_get_card(host->card);

	mmc_get_card(host->card, NULL);



	/*

	 * Just check if our card has been removed.

	 */

	err = _mmc_detect_card_removed(host);



	mmc_put_card(host->card);

	mmc_put_card(host->card, NULL);



	if (err) {

		mmc_sd_remove(host);