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 <tgih.jun@samsung.com>
Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 5513785..32492b7 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -51,6 +51,7 @@
 	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 @@
 	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 e918120..67bac37 100644
--- a/include/linux/mmc/core.h
+++ b/include/linux/mmc/core.h
@@ -177,6 +177,8 @@
 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 cd10208..16e9338 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -239,6 +239,7 @@
 	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 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 8a05a21..160e4c5 100644
--- a/include/linux/mmc/mmc.h
+++ b/include/linux/mmc/mmc.h
@@ -270,6 +270,8 @@
  * 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 @@
 #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