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

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

Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
This commit is contained in:
Seungwon Jeon
2011-10-14 14:03:21 +09:00
committed by Chris Ball
parent 71fe3eb0d0
commit 881d1c25f7
7 changed files with 104 additions and 6 deletions
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14
drivers/mmc/card/block.c
View File

@@ -851,16 +851,18 @@ out:
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;
}
/*

63
drivers/mmc/core/core.c
View File

@@ -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;
}

23
drivers/mmc/core/mmc.c
View File

@@ -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;