Adrian Hunter wrote:
> On 08/09/11 10:29, Seungwon Jeon wrote:
> > 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....@samsung.com>
> > ---
> > This patch is base on [PATCH v3] mmc: core: Add default timeout value
> for CMD6
> >
> > drivers/mmc/card/block.c | 14 ++++++----
> > drivers/mmc/core/core.c | 62
> ++++++++++++++++++++++++++++++++++++++++++++++
> > drivers/mmc/core/mmc.c | 23 +++++++++++++++++
> > include/linux/mmc/card.h | 2 +
> > include/linux/mmc/core.h | 2 +
> > include/linux/mmc/host.h | 3 ++
> > include/linux/mmc/mmc.h | 3 ++
> > 7 files changed, 103 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
> > index e702c61..84fa4bb 100644
> > --- a/drivers/mmc/card/block.c
> > +++ b/drivers/mmc/card/block.c
> > @@ -779,16 +779,18 @@ 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;
> > }
> >
> > /*
> > diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
> > index 557856b..14c2431 100644
> > --- a/drivers/mmc/core/core.c
> > +++ b/drivers/mmc/core/core.c
> > @@ -1987,6 +1987,64 @@ 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->caps& MMC_CAP_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->caps& MMC_CAP_CACHE_CTRL))
> > + return err;
> > +
>
> This patch does not cover code paths for removable cards.
> For clarity and in case a platform does not set non-removable
> flags for eMMC, a check is needed here e.g.
>
> if (mmc_card_is_removable(host))
> return 0;
>
Is it worry about normal MMC card type and?
Then, "card->ext_csd.cache_size" is a good condition for deciding cache control.
Or even though eMMC should be non-removable type, platform does not set
non-removable for eMMC type mistakenly?
I can't catch the meaning exactly.
Please let me know.
Thanks.
Beset regards,
Seungwon Jeon.
> > + 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
> >
> > /**
> > @@ -2001,6 +2059,9 @@ 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) {
> > @@ -2025,6 +2086,7 @@ int mmc_suspend_host(struct mmc_host *host)
> > if (!err&& !mmc_card_keep_power(host))
> > mmc_power_off(host);
> >
> > +out:
> > return err;
> > }
> >
> > diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
> > index ea58a0c..035112b 100644
> > --- a/drivers/mmc/core/mmc.c
> > +++ b/drivers/mmc/core/mmc.c
> > @@ -419,6 +419,12 @@ static int mmc_read_ext_csd(struct mmc_card *card,
> u8 *ext_csd)
> > */
> > 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;
> > }
> > @@ -851,6 +857,23 @@ static int mmc_init_card(struct mmc_host *host, u32
> ocr,
> > }
> > }
> >
> > + /*
> > + * If cache size is higher than 0, this indicates
> > + * the the existence of cache and it can be turned on.
> > + */
> > + if ((host->caps& MMC_CAP_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;
> >
> > diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
> > index b713abf..519660b 100644
> > --- a/include/linux/mmc/card.h
> > +++ b/include/linux/mmc/card.h
> > @@ -50,6 +50,7 @@ struct mmc_ext_csd {
> > u8 rel_sectors;
> > u8 rel_param;
> > u8 part_config;
> > + u8 cache_ctrl;
> > unsigned int part_time; /* Units: ms */
> > unsigned int sa_timeout; /* Units: 100ns */
> > unsigned int generic_cmd6_time; /* Units: 10ms */
> > @@ -65,6 +66,7 @@ struct mmc_ext_csd {
> > unsigned long long enhanced_area_offset; /* Units: Byte */
> > unsigned int enhanced_area_size; /* Units: KB */
> > unsigned int boot_size; /* in bytes */
> > + unsigned int cache_size; /* Units: KB */
> > u8 raw_partition_support; /* 160 */
> > u8 raw_erased_mem_count; /* 181 */
> > u8 raw_ext_csd_structure; /* 194 */
> > diff --git a/include/linux/mmc/core.h b/include/linux/mmc/core.h
> > index b8b1b7a..45b4acf 100644
> > --- a/include/linux/mmc/core.h
> > +++ b/include/linux/mmc/core.h
> > @@ -171,6 +171,8 @@ 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
> > diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
> > index 4c4bddf..6d0006d 100644
> > --- a/include/linux/mmc/host.h
> > +++ b/include/linux/mmc/host.h
> > @@ -230,6 +230,7 @@ struct mmc_host {
> > #define MMC_CAP_MAX_CURRENT_600 (1<< 28) /* Host max current
> limit is 600mA */
> > #define MMC_CAP_MAX_CURRENT_800 (1<< 29) /* Host max current
> limit is 800mA */
> > #define MMC_CAP_CMD23 (1<< 30) /* CMD23 supported. */
> > +#define MMC_CAP_CACHE_CTRL (1<< 31) /* Allow cache
> control. */
> >
> > mmc_pm_flag_t pm_caps; /* supported pm features */
> >
> > @@ -335,6 +336,8 @@ extern int mmc_power_restore_host(struct mmc_host
> *host);
> > extern void mmc_detect_change(struct mmc_host *, unsigned long delay);
> > extern void mmc_request_done(struct mmc_host *, struct mmc_request *);
> >
> > +extern int mmc_cache_ctrl(struct mmc_host *, u8);
> > +
> > static inline void mmc_signal_sdio_irq(struct mmc_host *host)
> > {
> > host->ops->enable_sdio_irq(host, 0);
> > diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
> > index e869f00..b7fa9f7 100644
> > --- a/include/linux/mmc/mmc.h
> > +++ b/include/linux/mmc/mmc.h
> > @@ -270,6 +270,8 @@ struct _mmc_csd {
> > * EXT_CSD fields
> > */
> >
> > +#define EXT_CSD_FLUSH_CACHE 32 /* W */
> > +#define EXT_CSD_CACHE_CTRL 33 /* R/W */
> > #define EXT_CSD_PARTITION_ATTRIBUTE 156 /* R/W */
> > #define EXT_CSD_PARTITION_SUPPORT 160 /* RO */
> > #define EXT_CSD_WR_REL_PARAM 166 /* RO */
> > @@ -294,6 +296,7 @@ struct _mmc_csd {
> > #define EXT_CSD_SEC_FEATURE_SUPPORT 231 /* RO */
> > #define EXT_CSD_TRIM_MULT 232 /* RO */
> > #define EXT_CSD_GENERIC_CMD6_TIME 248 /* RO */
> > +#define EXT_CSD_CACHE_SIZE 249 /* RO, 4 bytes */
> >
> > /*
> > * EXT_CSD field definitions
> > --
> > 1.7.0.4
> >
> > --
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