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;
+ 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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