mmc: support BKOPS feature for eMMC
Enable eMMC background operations (BKOPS) feature.
If URGENT_BKOPS is set after a response, note that BKOPS are required.
Immediately run BKOPS if required. Read/write operations should be
requested during BKOPS(LEVEL-1), then issue HPI to interrupt the
ongoing BKOPS and service the foreground operation.
(This patch only controls the LEVEL2/3.)
When repeating the writing 1GB data, at a certain time, performance is
decreased. At that time, card triggers the Level-3 or Level-2. After
running bkops, performance is recovered.
Future considerations:
* Check BKOPS_LEVEL=1 and start BKOPS in a preventive manner.
* Interrupt ongoing BKOPS before powering off the card.
* How do we get BKOPS_STATUS value (periodically send ext_csd command)?
* If using periodic bkops, also consider runtime_pm control.
Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Konstantin Dorfman <kdorfman@codeaurora.org>
Reviewed-by: Maya Erez <merez@codeaurora.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/include/linux/mmc/core.h b/include/linux/mmc/core.h
index 1b431c7..9b9cdaf 100644
--- a/include/linux/mmc/core.h
+++ b/include/linux/mmc/core.h
@@ -134,6 +134,8 @@
struct mmc_card;
struct mmc_async_req;
+extern int mmc_stop_bkops(struct mmc_card *);
+extern int mmc_read_bkops_status(struct mmc_card *);
extern struct mmc_async_req *mmc_start_req(struct mmc_host *,
struct mmc_async_req *, int *);
extern int mmc_interrupt_hpi(struct mmc_card *);
@@ -142,6 +144,8 @@
extern int mmc_app_cmd(struct mmc_host *, struct mmc_card *);
extern int mmc_wait_for_app_cmd(struct mmc_host *, struct mmc_card *,
struct mmc_command *, int);
+extern void mmc_start_bkops(struct mmc_card *card, bool from_exception);
+extern int __mmc_switch(struct mmc_card *, u8, u8, u8, unsigned int, bool);
extern int mmc_switch(struct mmc_card *, u8, u8, u8, unsigned int);
#define MMC_ERASE_ARG 0x00000000