From 881d1c25f765938a95def5afe39486ce39f9fc96 Mon Sep 17 00:00:00 2001 From: Seungwon Jeon Date: Fri, 14 Oct 2011 14:03:21 +0900 Subject: [PATCH] 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: Seungwon Jeon Signed-off-by: Jaehoon Chung Signed-off-by: Chris Ball --- drivers/mmc/card/block.c | 14 +++++---- drivers/mmc/core/core.c | 63 ++++++++++++++++++++++++++++++++++++++++ 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, 104 insertions(+), 6 deletions(-) diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c index 370472797fff..c0cb225bbb47 100644 --- a/drivers/mmc/card/block.c +++ b/drivers/mmc/card/block.c @@ -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; } /* diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index 772de2cdfd1d..235bb6a1f973 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -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; } diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index 793901519208..de5900aa81cd 100644 --- a/drivers/mmc/core/mmc.c +++ b/drivers/mmc/core/mmc.c @@ -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; diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h index 551378508784..32492b78aed6 100644 --- a/include/linux/mmc/card.h +++ b/include/linux/mmc/card.h @@ -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 */ diff --git a/include/linux/mmc/core.h b/include/linux/mmc/core.h index e918120235bd..67bac374d122 100644 --- a/include/linux/mmc/core.h +++ b/include/linux/mmc/core.h @@ -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 diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h index cd10208d9a06..16e9338944e8 100644 --- a/include/linux/mmc/host.h +++ b/include/linux/mmc/host.h @@ -239,6 +239,7 @@ struct mmc_host { unsigned int caps2; /* More host capabilities */ #define MMC_CAP2_BOOTPART_NOACC (1 << 0) /* Boot partition no access */ +#define MMC_CAP2_CACHE_CTRL (1 << 1) /* Allow cache control */ #define MMC_CAP2_POWEROFF_NOTIFY (1 << 2) /* Notify poweroff supported */ mmc_pm_flag_t pm_caps; /* supported pm features */ @@ -349,6 +350,8 @@ 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 8a05a21fc7c3..160e4c5bdae0 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_POWER_OFF_NOTIFICATION 34 /* R/W */ #define EXT_CSD_GP_SIZE_MULT 143 /* R/W */ #define EXT_CSD_PARTITION_ATTRIBUTE 156 /* R/W */ @@ -308,6 +310,7 @@ struct _mmc_csd { #define EXT_CSD_PWR_CL_DDR_52_360 239 /* RO */ #define EXT_CSD_POWER_OFF_LONG_TIME 247 /* RO */ #define EXT_CSD_GENERIC_CMD6_TIME 248 /* RO */ +#define EXT_CSD_CACHE_SIZE 249 /* RO, 4 bytes */ /* * EXT_CSD field definitions -- GitLab