diff --git a/drivers/mmc/core/bus.c b/drivers/mmc/core/bus.c
index 0ddaee0eae54..30763b342bd3 100644
--- a/drivers/mmc/core/bus.c
+++ b/drivers/mmc/core/bus.c
@@ -321,7 +321,9 @@ int mmc_add_card(struct mmc_card *card)
 	case MMC_TYPE_SD:
 		type = "SD";
 		if (mmc_card_blockaddr(card)) {
-			if (mmc_card_ext_capacity(card))
+			if (mmc_card_ult_capacity(card))
+				type = "SDUC";
+			else if (mmc_card_ext_capacity(card))
 				type = "SDXC";
 			else
 				type = "SDHC";
diff --git a/drivers/mmc/core/card.h b/drivers/mmc/core/card.h
index b7754a1b8d97..64dcb463a4f4 100644
--- a/drivers/mmc/core/card.h
+++ b/drivers/mmc/core/card.h
@@ -23,6 +23,7 @@
 #define MMC_CARD_SDXC		(1<<3)		/* card is SDXC */
 #define MMC_CARD_REMOVED	(1<<4)		/* card has been removed */
 #define MMC_STATE_SUSPENDED	(1<<5)		/* card is suspended */
+#define MMC_CARD_SDUC		(1<<6)		/* card is SDUC */
 
 #define mmc_card_present(c)	((c)->state & MMC_STATE_PRESENT)
 #define mmc_card_readonly(c)	((c)->state & MMC_STATE_READONLY)
@@ -30,11 +31,13 @@
 #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_suspended(c)	((c)->state & MMC_STATE_SUSPENDED)
+#define mmc_card_ult_capacity(c) ((c)->state & MMC_CARD_SDUC)
 
 #define mmc_card_set_present(c)	((c)->state |= MMC_STATE_PRESENT)
 #define mmc_card_set_readonly(c) ((c)->state |= MMC_STATE_READONLY)
 #define mmc_card_set_blockaddr(c) ((c)->state |= MMC_STATE_BLOCKADDR)
 #define mmc_card_set_ext_capacity(c) ((c)->state |= MMC_CARD_SDXC)
+#define mmc_card_set_ult_capacity(c) ((c)->state |= MMC_CARD_SDUC)
 #define mmc_card_set_removed(c) ((c)->state |= MMC_CARD_REMOVED)
 #define mmc_card_set_suspended(c) ((c)->state |= MMC_STATE_SUSPENDED)
 #define mmc_card_clr_suspended(c) ((c)->state &= ~MMC_STATE_SUSPENDED)
diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index ee37ad14e79e..eb9990d9db56 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -114,7 +114,7 @@ void mmc_decode_cid(struct mmc_card *card)
 /*
  * Given a 128-bit response, decode to our card CSD structure.
  */
-static int mmc_decode_csd(struct mmc_card *card)
+static int mmc_decode_csd(struct mmc_card *card, bool is_sduc)
 {
 	struct mmc_csd *csd = &card->csd;
 	unsigned int e, m, csd_struct;
@@ -158,9 +158,10 @@ static int mmc_decode_csd(struct mmc_card *card)
 			mmc_card_set_readonly(card);
 		break;
 	case 1:
+	case 2:
 		/*
-		 * This is a block-addressed SDHC or SDXC card. Most
-		 * interesting fields are unused and have fixed
+		 * This is a block-addressed SDHC, SDXC or SDUC card.
+		 * Most interesting fields are unused and have fixed
 		 * values. To avoid getting tripped by buggy cards,
 		 * we assume those fixed values ourselves.
 		 */
@@ -173,14 +174,19 @@ static int mmc_decode_csd(struct mmc_card *card)
 		e = UNSTUFF_BITS(resp, 96, 3);
 		csd->max_dtr	  = tran_exp[e] * tran_mant[m];
 		csd->cmdclass	  = UNSTUFF_BITS(resp, 84, 12);
-		csd->c_size	  = UNSTUFF_BITS(resp, 48, 22);
 
-		/* SDXC cards have a minimum C_SIZE of 0x00FFFF */
-		if (csd->c_size >= 0xFFFF)
+		if (csd_struct == 1)
+			m = UNSTUFF_BITS(resp, 48, 22);
+		else
+			m = UNSTUFF_BITS(resp, 48, 28);
+		csd->c_size = m;
+
+		if (csd->c_size >= 0x400000 && is_sduc)
+			mmc_card_set_ult_capacity(card);
+		else if (csd->c_size >= 0xFFFF)
 			mmc_card_set_ext_capacity(card);
 
-		m = UNSTUFF_BITS(resp, 48, 22);
-		csd->capacity     = (1 + m) << 10;
+		csd->capacity     = (1 + (typeof(sector_t))m) << 10;
 
 		csd->read_blkbits = 9;
 		csd->read_partial = 0;
@@ -841,8 +847,11 @@ int mmc_sd_get_cid(struct mmc_host *host, u32 ocr, u32 *cid, u32 *rocr)
 	 * block-addressed SDHC cards.
 	 */
 	err = mmc_send_if_cond(host, ocr);
-	if (!err)
+	if (!err) {
 		ocr |= SD_OCR_CCS;
+		/* Set HO2T as well - SDUC card won't respond otherwise */
+		ocr |= SD_OCR_2T;
+	}
 
 	/*
 	 * If the host supports one of UHS-I modes, request the card
@@ -887,7 +896,7 @@ int mmc_sd_get_cid(struct mmc_host *host, u32 ocr, u32 *cid, u32 *rocr)
 	return err;
 }
 
-int mmc_sd_get_csd(struct mmc_card *card)
+int mmc_sd_get_csd(struct mmc_card *card, bool is_sduc)
 {
 	int err;
 
@@ -898,7 +907,7 @@ int mmc_sd_get_csd(struct mmc_card *card)
 	if (err)
 		return err;
 
-	err = mmc_decode_csd(card);
+	err = mmc_decode_csd(card, is_sduc);
 	if (err)
 		return err;
 
@@ -1453,7 +1462,7 @@ static int mmc_sd_init_card(struct mmc_host *host, u32 ocr,
 	}
 
 	if (!oldcard) {
-		err = mmc_sd_get_csd(card);
+		err = mmc_sd_get_csd(card, false);
 		if (err)
 			goto free_card;
 
diff --git a/drivers/mmc/core/sd.h b/drivers/mmc/core/sd.h
index fe6dd46927a4..7e8beface2ca 100644
--- a/drivers/mmc/core/sd.h
+++ b/drivers/mmc/core/sd.h
@@ -10,7 +10,7 @@ struct mmc_host;
 struct mmc_card;
 
 int mmc_sd_get_cid(struct mmc_host *host, u32 ocr, u32 *cid, u32 *rocr);
-int mmc_sd_get_csd(struct mmc_card *card);
+int mmc_sd_get_csd(struct mmc_card *card, bool is_sduc);
 void mmc_decode_cid(struct mmc_card *card);
 int mmc_sd_setup_card(struct mmc_host *host, struct mmc_card *card,
 	bool reinit);
diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
index 4fb247fde5c0..9566837c9848 100644
--- a/drivers/mmc/core/sdio.c
+++ b/drivers/mmc/core/sdio.c
@@ -769,7 +769,7 @@ static int mmc_sdio_init_card(struct mmc_host *host, u32 ocr,
 	 * Read CSD, before selecting the card
 	 */
 	if (!oldcard && mmc_card_sd_combo(card)) {
-		err = mmc_sd_get_csd(card);
+		err = mmc_sd_get_csd(card, false);
 		if (err)
 			goto remove;
 
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index f34407cc2788..f39bce322365 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -35,7 +35,7 @@ struct mmc_csd {
 	unsigned int		wp_grp_size;
 	unsigned int		read_blkbits;
 	unsigned int		write_blkbits;
-	unsigned int		capacity;
+	sector_t		capacity;
 	unsigned int		read_partial:1,
 				read_misalign:1,
 				write_partial:1,
diff --git a/include/linux/mmc/sd.h b/include/linux/mmc/sd.h
index 6727576a8755..865cc0ca8543 100644
--- a/include/linux/mmc/sd.h
+++ b/include/linux/mmc/sd.h
@@ -36,6 +36,7 @@
 /* OCR bit definitions */
 #define SD_OCR_S18R		(1 << 24)    /* 1.8V switching request */
 #define SD_ROCR_S18A		SD_OCR_S18R  /* 1.8V switching accepted by card */
+#define SD_OCR_2T		(1 << 27)    /* HO2T/CO2T - SDUC support */
 #define SD_OCR_XPC		(1 << 28)    /* SDXC power control */
 #define SD_OCR_CCS		(1 << 30)    /* Card Capacity Status */
 
