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Commit 881d1c25 authored by Seungwon Jeon's avatar Seungwon Jeon Committed by Chris Ball
Browse files

mmc: core: Add cache control for eMMC4.5 device 



This patch adds cache feature of eMMC4.5 Spec.
If device supports cache capability, host can utilize some specific
operations.

Signed-off-by: default avatarSeungwon Jeon <tgih.jun@samsung.com>
Signed-off-by: default avatarJaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: default avatarChris Ball <cjb@laptop.org>
parent 71fe3eb0

drivers/mmc/card/block.c

+8 −6
Original line number Diff line number Diff line
@@ -851,16 +851,18 @@ static int mmc_blk_issue_secdiscard_rq(struct mmc_queue *mq, 
static int mmc_blk_issue_flush(struct mmc_queue *mq, struct request *req)

{

	struct mmc_blk_data *md = mq->data;

	struct mmc_card *card = md->queue.card;

	int ret = 0;



	ret = mmc_flush_cache(card);

	if (ret)

		ret = -EIO;



	/*

	 * No-op, only service this because we need REQ_FUA for reliable

	 * writes.

	 */

	spin_lock_irq(&md->lock);

	__blk_end_request_all(req, 0);

	__blk_end_request_all(req, ret);

	spin_unlock_irq(&md->lock);



	return 1;

	return ret ? 0 : 1;

}



/*

drivers/mmc/core/core.c

+63 −0
Original line number Diff line number Diff line
@@ -2158,6 +2158,65 @@ int mmc_card_can_sleep(struct mmc_host *host) 
}

EXPORT_SYMBOL(mmc_card_can_sleep);



/*

 * Flush the cache to the non-volatile storage.

 */

int mmc_flush_cache(struct mmc_card *card)

{

	struct mmc_host *host = card->host;

	int err = 0;



	if (!(host->caps2 & MMC_CAP2_CACHE_CTRL))

		return err;



	if (mmc_card_mmc(card) &&

			(card->ext_csd.cache_size > 0) &&

			(card->ext_csd.cache_ctrl & 1)) {

		err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,

				EXT_CSD_FLUSH_CACHE, 1, 0);

		if (err)

			pr_err("%s: cache flush error %d\n",

					mmc_hostname(card->host), err);

	}



	return err;

}

EXPORT_SYMBOL(mmc_flush_cache);



/*

 * Turn the cache ON/OFF.

 * Turning the cache OFF shall trigger flushing of the data

 * to the non-volatile storage.

 */

int mmc_cache_ctrl(struct mmc_host *host, u8 enable)

{

	struct mmc_card *card = host->card;

	int err = 0;



	if (!(host->caps2 & MMC_CAP2_CACHE_CTRL) ||

			mmc_card_is_removable(host))

		return err;



	if (card && mmc_card_mmc(card) &&

			(card->ext_csd.cache_size > 0)) {

		enable = !!enable;



		if (card->ext_csd.cache_ctrl ^ enable)

			err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,

					EXT_CSD_CACHE_CTRL, enable, 0);

		if (err)

			pr_err("%s: cache %s error %d\n",

					mmc_hostname(card->host),

					enable ? "on" : "off",

					err);

		else

			card->ext_csd.cache_ctrl = enable;

	}



	return err;

}

EXPORT_SYMBOL(mmc_cache_ctrl);



#ifdef CONFIG_PM



/**
@@ -2172,6 +2231,9 @@ int mmc_suspend_host(struct mmc_host *host) 
		cancel_delayed_work(&host->disable);

	cancel_delayed_work(&host->detect);

	mmc_flush_scheduled_work();

	err = mmc_cache_ctrl(host, 0);

	if (err)

		goto out;



	mmc_bus_get(host);

	if (host->bus_ops && !host->bus_dead) {
@@ -2197,6 +2259,7 @@ int mmc_suspend_host(struct mmc_host *host) 
	if (!err && !mmc_card_keep_power(host))

		mmc_power_off(host);



out:

	return err;

}

drivers/mmc/core/mmc.c

+23 −0
Original line number Diff line number Diff line
@@ -470,6 +470,12 @@ static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd) 
	} else

		card->ext_csd.generic_cmd6_time = 0;



	card->ext_csd.cache_size =

		ext_csd[EXT_CSD_CACHE_SIZE + 0] << 0 |

		ext_csd[EXT_CSD_CACHE_SIZE + 1] << 8 |

		ext_csd[EXT_CSD_CACHE_SIZE + 2] << 16 |

		ext_csd[EXT_CSD_CACHE_SIZE + 3] << 24;



out:

	return err;

}
@@ -1020,6 +1026,23 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr, 
		}

	}



	/*

	 * If cache size is higher than 0, this indicates

	 * the existence of cache and it can be turned on.

	 */

	if ((host->caps2 & MMC_CAP2_CACHE_CTRL) &&

			card->ext_csd.cache_size > 0) {

		err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,

				EXT_CSD_CACHE_CTRL, 1, 0);

		if (err && err != -EBADMSG)

			goto free_card;



		/*

		 * Only if no error, cache is turned on successfully.

		 */

		card->ext_csd.cache_ctrl = err ? 0 : 1;

	}



	if (!oldcard)

		host->card = card;

include/linux/mmc/card.h

+2 −0
Original line number Diff line number Diff line
@@ -51,6 +51,7 @@ struct mmc_ext_csd { 
	u8			rel_sectors;

	u8			rel_param;

	u8			part_config;

	u8			cache_ctrl;

	u8			rst_n_function;

	unsigned int		part_time;		/* Units: ms */

	unsigned int		sa_timeout;		/* Units: 100ns */
@@ -67,6 +68,7 @@ struct mmc_ext_csd { 
	bool			enhanced_area_en;	/* enable bit */

	unsigned long long	enhanced_area_offset;	/* Units: Byte */

	unsigned int		enhanced_area_size;	/* Units: KB */

	unsigned int		cache_size;		/* Units: KB */

	u8			raw_partition_support;	/* 160 */

	u8			raw_erased_mem_count;	/* 181 */

	u8			raw_ext_csd_structure;	/* 194 */

include/linux/mmc/core.h

+2 −0
Original line number Diff line number Diff line
@@ -177,6 +177,8 @@ extern void mmc_release_host(struct mmc_host *host); 
extern void mmc_do_release_host(struct mmc_host *host);

extern int mmc_try_claim_host(struct mmc_host *host);



extern int mmc_flush_cache(struct mmc_card *);



/**

 *	mmc_claim_host - exclusively claim a host

 *	@host: mmc host to claim