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>

3 files changed, 31 insertions, 0 deletions

diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 4b27f9f503e..78cc3be8539 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -76,10 +76,13 @@ struct mmc_ext_csd {
 	bool			hpi_en;			/* HPI enablebit */
 	bool			hpi;			/* HPI support bit */
 	unsigned int		hpi_cmd;		/* cmd used as HPI */
+	bool			bkops;		/* background support bit */
+	bool			bkops_en;	/* background enable bit */
 	unsigned int            data_sector_size;       /* 512 bytes or 4KB */
 	unsigned int            data_tag_unit_size;     /* DATA TAG UNIT size */
 	unsigned int		boot_ro_lock;		/* ro lock support */
 	bool			boot_ro_lockable;
+	u8			raw_exception_status;	/* 53 */
 	u8			raw_partition_support;	/* 160 */
 	u8			raw_erased_mem_count;	/* 181 */
 	u8			raw_ext_csd_structure;	/* 194 */
@@ -93,6 +96,7 @@ struct mmc_ext_csd {
 	u8			raw_sec_erase_mult;	/* 230 */
 	u8			raw_sec_feature_support;/* 231 */
 	u8			raw_trim_mult;		/* 232 */
+	u8			raw_bkops_status;	/* 246 */
 	u8			raw_sectors[4];		/* 212 - 4 bytes */
 
 	unsigned int            feature_support;
@@ -226,6 +230,7 @@ struct mmc_card {
 #define MMC_CARD_REMOVED	(1<<7)		/* card has been removed */
 #define MMC_STATE_HIGHSPEED_200	(1<<8)		/* card is in HS200 mode */
 #define MMC_STATE_SLEEP		(1<<9)		/* card is in sleep state */
+#define MMC_STATE_DOING_BKOPS	(1<<10)		/* card is doing BKOPS */
 	unsigned int		quirks; 	/* card quirks */
 #define MMC_QUIRK_LENIENT_FN0	(1<<0)		/* allow SDIO FN0 writes outside of the VS CCCR range */
 #define MMC_QUIRK_BLKSZ_FOR_BYTE_MODE (1<<1)	/* use func->cur_blksize */
@@ -393,6 +398,7 @@ static inline void __maybe_unused remove_quirk(struct mmc_card *card, int data)
 #define mmc_card_ext_capacity(c) ((c)->state & MMC_CARD_SDXC)
 #define mmc_card_removed(c)	((c) && ((c)->state & MMC_CARD_REMOVED))
 #define mmc_card_is_sleep(c)	((c)->state & MMC_STATE_SLEEP)
+#define mmc_card_doing_bkops(c)	((c)->state & MMC_STATE_DOING_BKOPS)
 
 #define mmc_card_set_present(c)	((c)->state |= MMC_STATE_PRESENT)
 #define mmc_card_set_readonly(c) ((c)->state |= MMC_STATE_READONLY)
@@ -405,7 +411,9 @@ static inline void __maybe_unused remove_quirk(struct mmc_card *card, int data)
 #define mmc_card_set_ext_capacity(c) ((c)->state |= MMC_CARD_SDXC)
 #define mmc_card_set_removed(c) ((c)->state |= MMC_CARD_REMOVED)
 #define mmc_card_set_sleep(c)	((c)->state |= MMC_STATE_SLEEP)
+#define mmc_card_set_doing_bkops(c)	((c)->state |= MMC_STATE_DOING_BKOPS)
 
+#define mmc_card_clr_doing_bkops(c)	((c)->state &= ~MMC_STATE_DOING_BKOPS)
 #define mmc_card_clr_sleep(c)	((c)->state &= ~MMC_STATE_SLEEP)
 /*
  * Quirk add/remove for MMC products.
diff --git a/include/linux/mmc/core.h b/include/linux/mmc/core.h
index 1b431c728b9..9b9cdafc773 100644
--- a/include/linux/mmc/core.h
+++ b/include/linux/mmc/core.h
@@ -134,6 +134,8 @@ struct mmc_host;
 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_wait_for_cmd(struct mmc_host *, struct mmc_command *, int);
 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
diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
index d425cab144d..01e4b394029 100644
--- a/include/linux/mmc/mmc.h
+++ b/include/linux/mmc/mmc.h
@@ -139,6 +139,7 @@ static inline bool mmc_op_multi(u32 opcode)
 #define R1_CURRENT_STATE(x)	((x & 0x00001E00) >> 9)	/* sx, b (4 bits) */
 #define R1_READY_FOR_DATA	(1 << 8)	/* sx, a */
 #define R1_SWITCH_ERROR		(1 << 7)	/* sx, c */
+#define R1_EXCEPTION_EVENT	(1 << 6)	/* sx, a */
 #define R1_APP_CMD		(1 << 5)	/* sr, c */
 
 #define R1_STATE_IDLE	0
@@ -274,12 +275,15 @@ struct _mmc_csd {
 #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_EXP_EVENTS_STATUS	54	/* RO */
 #define EXT_CSD_DATA_SECTOR_SIZE	61	/* R */
 #define EXT_CSD_GP_SIZE_MULT		143	/* R/W */
 #define EXT_CSD_PARTITION_ATTRIBUTE	156	/* R/W */
 #define EXT_CSD_PARTITION_SUPPORT	160	/* RO */
 #define EXT_CSD_HPI_MGMT		161	/* R/W */
 #define EXT_CSD_RST_N_FUNCTION		162	/* R/W */
+#define EXT_CSD_BKOPS_EN		163	/* R/W */
+#define EXT_CSD_BKOPS_START		164	/* W */
 #define EXT_CSD_SANITIZE_START		165     /* W */
 #define EXT_CSD_WR_REL_PARAM		166	/* RO */
 #define EXT_CSD_BOOT_WP			173	/* R/W */
@@ -313,11 +317,13 @@ struct _mmc_csd {
 #define EXT_CSD_PWR_CL_200_360		237	/* RO */
 #define EXT_CSD_PWR_CL_DDR_52_195	238	/* RO */
 #define EXT_CSD_PWR_CL_DDR_52_360	239	/* RO */
+#define EXT_CSD_BKOPS_STATUS		246	/* 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 */
 #define EXT_CSD_TAG_UNIT_SIZE		498	/* RO */
 #define EXT_CSD_DATA_TAG_SUPPORT	499	/* RO */
+#define EXT_CSD_BKOPS_SUPPORT		502	/* RO */
 #define EXT_CSD_HPI_FEATURES		503	/* RO */
 
 /*
@@ -378,6 +384,19 @@ struct _mmc_csd {
 #define EXT_CSD_PWR_CL_8BIT_SHIFT	4
 #define EXT_CSD_PWR_CL_4BIT_SHIFT	0
 /*
+ * EXCEPTION_EVENT_STATUS field
+ */
+#define EXT_CSD_URGENT_BKOPS		BIT(0)
+#define EXT_CSD_DYNCAP_NEEDED		BIT(1)
+#define EXT_CSD_SYSPOOL_EXHAUSTED	BIT(2)
+#define EXT_CSD_PACKED_FAILURE		BIT(3)
+
+/*
+ * BKOPS status level
+ */
+#define EXT_CSD_BKOPS_LEVEL_2		0x2
+
+/*
  * MMC_SWITCH access modes
  */