diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 8ccae6452b9c..6673c0f33cc7 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -2137,8 +2137,12 @@ static int mmc_rescan_try_freq(struct mmc_host *host, unsigned freq)
 
 	mmc_go_idle(host);
 
-	if (!(host->caps2 & MMC_CAP2_NO_SD))
-		mmc_send_if_cond(host, host->ocr_avail);
+	if (!(host->caps2 & MMC_CAP2_NO_SD)) {
+		if (mmc_send_if_cond_pcie(host, host->ocr_avail))
+			goto out;
+		if (mmc_card_sd_express(host))
+			return 0;
+	}
 
 	/* Order's important: probe SDIO, then SD, then MMC */
 	if (!(host->caps2 & MMC_CAP2_NO_SDIO))
@@ -2153,6 +2157,7 @@ static int mmc_rescan_try_freq(struct mmc_host *host, unsigned freq)
 		if (!mmc_attach_mmc(host))
 			return 0;
 
+out:
 	mmc_power_off(host);
 	return -EIO;
 }
@@ -2280,6 +2285,12 @@ void mmc_rescan(struct work_struct *work)
 		goto out;
 	}
 
+	/* If an SD express card is present, then leave it as is. */
+	if (mmc_card_sd_express(host)) {
+		mmc_release_host(host);
+		goto out;
+	}
+
 	for (i = 0; i < ARRAY_SIZE(freqs); i++) {
 		unsigned int freq = freqs[i];
 		if (freq > host->f_max) {
diff --git a/drivers/mmc/core/host.h b/drivers/mmc/core/host.h
index 5e3b9534ffb2..ba407617ed23 100644
--- a/drivers/mmc/core/host.h
+++ b/drivers/mmc/core/host.h
@@ -77,5 +77,11 @@ static inline bool mmc_card_hs400es(struct mmc_card *card)
 	return card->host->ios.enhanced_strobe;
 }
 
+static inline bool mmc_card_sd_express(struct mmc_host *host)
+{
+	return host->ios.timing == MMC_TIMING_SD_EXP ||
+		host->ios.timing == MMC_TIMING_SD_EXP_1_2V;
+}
+
 #endif
 
diff --git a/drivers/mmc/core/sd_ops.c b/drivers/mmc/core/sd_ops.c
index 22bf528294b9..d61ff811218c 100644
--- a/drivers/mmc/core/sd_ops.c
+++ b/drivers/mmc/core/sd_ops.c
@@ -158,7 +158,8 @@ int mmc_send_app_op_cond(struct mmc_host *host, u32 ocr, u32 *rocr)
 	return err;
 }
 
-int mmc_send_if_cond(struct mmc_host *host, u32 ocr)
+static int __mmc_send_if_cond(struct mmc_host *host, u32 ocr, u8 pcie_bits,
+			      u32 *resp)
 {
 	struct mmc_command cmd = {};
 	int err;
@@ -171,7 +172,7 @@ int mmc_send_if_cond(struct mmc_host *host, u32 ocr)
 	 * SD 1.0 cards.
 	 */
 	cmd.opcode = SD_SEND_IF_COND;
-	cmd.arg = ((ocr & 0xFF8000) != 0) << 8 | test_pattern;
+	cmd.arg = ((ocr & 0xFF8000) != 0) << 8 | pcie_bits << 8 | test_pattern;
 	cmd.flags = MMC_RSP_SPI_R7 | MMC_RSP_R7 | MMC_CMD_BCR;
 
 	err = mmc_wait_for_cmd(host, &cmd, 0);
@@ -186,6 +187,50 @@ int mmc_send_if_cond(struct mmc_host *host, u32 ocr)
 	if (result_pattern != test_pattern)
 		return -EIO;
 
+	if (resp)
+		*resp = cmd.resp[0];
+
+	return 0;
+}
+
+int mmc_send_if_cond(struct mmc_host *host, u32 ocr)
+{
+	return __mmc_send_if_cond(host, ocr, 0, NULL);
+}
+
+int mmc_send_if_cond_pcie(struct mmc_host *host, u32 ocr)
+{
+	u32 resp = 0;
+	u8 pcie_bits = 0;
+	int ret;
+
+	if (host->caps2 & MMC_CAP2_SD_EXP) {
+		/* Probe card for SD express support via PCIe. */
+		pcie_bits = 0x10;
+		if (host->caps2 & MMC_CAP2_SD_EXP_1_2V)
+			/* Probe also for 1.2V support. */
+			pcie_bits = 0x30;
+	}
+
+	ret = __mmc_send_if_cond(host, ocr, pcie_bits, &resp);
+	if (ret)
+		return 0;
+
+	/* Continue with the SD express init, if the card supports it. */
+	resp &= 0x3000;
+	if (pcie_bits && resp) {
+		if (resp == 0x3000)
+			host->ios.timing = MMC_TIMING_SD_EXP_1_2V;
+		else
+			host->ios.timing = MMC_TIMING_SD_EXP;
+
+		/*
+		 * According to the spec the clock shall also be gated, but
+		 * let's leave this to the host driver for more flexibility.
+		 */
+		return host->ops->init_sd_express(host, &host->ios);
+	}
+
 	return 0;
 }
 
diff --git a/drivers/mmc/core/sd_ops.h b/drivers/mmc/core/sd_ops.h
index 2194cabfcfc5..3ba7b3cf4652 100644
--- a/drivers/mmc/core/sd_ops.h
+++ b/drivers/mmc/core/sd_ops.h
@@ -16,6 +16,7 @@ struct mmc_host;
 int mmc_app_set_bus_width(struct mmc_card *card, int width);
 int mmc_send_app_op_cond(struct mmc_host *host, u32 ocr, u32 *rocr);
 int mmc_send_if_cond(struct mmc_host *host, u32 ocr);
+int mmc_send_if_cond_pcie(struct mmc_host *host, u32 ocr);
 int mmc_send_relative_addr(struct mmc_host *host, unsigned int *rca);
 int mmc_app_send_scr(struct mmc_card *card);
 int mmc_sd_switch(struct mmc_card *card, int mode, int group,
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index c5b6e97cb21a..905cddc5e6f3 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -60,6 +60,8 @@ struct mmc_ios {
 #define MMC_TIMING_MMC_DDR52	8
 #define MMC_TIMING_MMC_HS200	9
 #define MMC_TIMING_MMC_HS400	10
+#define MMC_TIMING_SD_EXP	11
+#define MMC_TIMING_SD_EXP_1_2V	12
 
 	unsigned char	signal_voltage;		/* signalling voltage (1.8V or 3.3V) */
 
@@ -172,6 +174,9 @@ struct mmc_host_ops {
 	 */
 	int	(*multi_io_quirk)(struct mmc_card *card,
 				  unsigned int direction, int blk_size);
+
+	/* Initialize an SD express card, mandatory for MMC_CAP2_SD_EXP. */
+	int	(*init_sd_express)(struct mmc_host *host, struct mmc_ios *ios);
 };
 
 struct mmc_cqe_ops {
@@ -357,6 +362,8 @@ struct mmc_host {
 #define MMC_CAP2_HS200_1_2V_SDR	(1 << 6)        /* can support */
 #define MMC_CAP2_HS200		(MMC_CAP2_HS200_1_8V_SDR | \
 				 MMC_CAP2_HS200_1_2V_SDR)
+#define MMC_CAP2_SD_EXP		(1 << 7)	/* SD express via PCIe */
+#define MMC_CAP2_SD_EXP_1_2V	(1 << 8)	/* SD express 1.2V */
 #define MMC_CAP2_CD_ACTIVE_HIGH	(1 << 10)	/* Card-detect signal active high */
 #define MMC_CAP2_RO_ACTIVE_HIGH	(1 << 11)	/* Write-protect signal active high */
 #define MMC_CAP2_NO_PRESCAN_POWERUP (1 << 14)	/* Don't power up before scan */
