Merge tag 'mmc-v6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc

Pull MMC updates from Ulf Hansson:
 "MMC core:
   - Improve RPMB frame handling code
   - Add support for a new max-sd-hs-hz DT property to limit frequency
   - Add support to manage regulator-under-voltage events
   - Support regulator-under-voltage for eMMC to mitigate data
     corruptions
   - Add mmc_read_tuning() to allow a host to validate its tuning
     sequence
   - Add some helpers to align checks for CMD23 support
   - Read the CCCR register for SDIO over SPI rather than the
     unsupported CMD7

  MMC host:
   - Add COMPILE_TEST option for a couple of drivers
   - Convert drivers to use the modern PM macros
   - dw_mmc-exynos: Enable support for the Exynos8890 variant
   - mmc_spi: Don't use crc ack during multiple block read
   - renesas_sdhi: Enable 64-bit polling mode for R-Car gen3 and
     RZ/G2L SoCs
   - rtsx_usb: Add support for over-current-protection
   - sdhci-cadence: Add support for multi-block read gap tuning
   - sdhci-msm:
       - Add support for tuning for SDR50 mode for SD cards
       - Enable support for the Lemans variant
   - sdhci-pci: Disable SD card clock before update for a few
     Intel platforms
   - sdhci-pxav3: Add support for UHS pinctrl settings
   - tmio: Add 64-bit read/write support in polling mode

  MEMSTICK:
   - Convert to use timeouts to prevent indefinite waiting
   - rtsx_usb: Add support for over-current-protection"

* tag 'mmc-v6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc: (77 commits)
  dt-bindings: mmc: samsung,exynos-dw-mshc: add specific compatible for exynos8890
  mmc: select REGMAP_MMIO with MMC_LOONGSON2
  mmc: add COMPILE_TEST to multiple drivers
  mmc: core: Improve RPMB frame handling code
  mmc: core: Fix variable shadowing in mmc_route_rpmb_frames()
  mmc: core: Parse and use the new max-sd-hs-hz DT property
  dt-bindings: mmc: controller: Add max-sd-hs-hz property
  mmc: sdhci-msm: Enable tuning for SDR50 mode for SD card
  dt-bindings: mmc: sdhci-msm: Document the Lemans compatible
  mmc: sh_mmcif: Remove dummy PM resume callback
  dt-bindings: mmc: sdhci-pxa: Add minItems to pinctrl-names
  mmc: sdio: Drop dev_pm_domain_detach() call
  mmc: dw_mmc-rockchip: use modern PM macros
  mmc: dw_mmc-pci: use modern PM macros
  mmc: dw_mmc-k3: use modern PM macros
  mmc: dw_mmc: exynos: use modern PM macros
  mmc: via-sdmmc: use modern PM macros
  mmc: sdhci-msm: use modern PM macros
  mmc: mtk-sd: use modern PM macros
  mmc: wmt-sdmmc: use modern PM macros
  ...

Documentation/devicetree/bindings/mmc/fsl,esdhc.yaml

@@ -90,6 +90,7 @@ required:
 
 allOf:
   - $ref: sdhci-common.yaml#
+  - $ref: mmc-controller-common.yaml#
 
 unevaluatedProperties: false
 

Documentation/devicetree/bindings/mmc/mmc-controller-common.yaml

@@ -93,6 +93,14 @@ properties:
     minimum: 400000
     maximum: 384000000
 
+  max-sd-hs-hz:
+    description: |
+      Maximum frequency (in Hz) to be used for SD cards operating in
+      High-Speed (HS) mode.
+    minimum: 400000
+    maximum: 50000000
+    default: 50000000
+
   disable-wp:
     $ref: /schemas/types.yaml#/definitions/flag
     description:

Documentation/devicetree/bindings/mmc/samsung,exynos-dw-mshc.yaml

@@ -31,6 +31,7 @@ properties:
               - samsung,exynos5433-dw-mshc-smu
               - samsung,exynos7885-dw-mshc-smu
               - samsung,exynos850-dw-mshc-smu
+              - samsung,exynos8890-dw-mshc-smu
               - samsung,exynos8895-dw-mshc-smu
           - const: samsung,exynos7-dw-mshc-smu
 

Documentation/devicetree/bindings/mmc/sdhci-msm.yaml

@@ -48,6 +48,7 @@ properties:
               - qcom,qcs615-sdhci
               - qcom,qcs8300-sdhci
               - qcom,qdu1000-sdhci
+              - qcom,sa8775p-sdhci
               - qcom,sar2130p-sdhci
               - qcom,sc7180-sdhci
               - qcom,sc7280-sdhci

Documentation/devicetree/bindings/mmc/sdhci-pxa.yaml

@@ -44,12 +44,29 @@ allOf:
           items:
             - const: default
             - const: state_cmd_gpio
-        pinctrl-0:
-          description:
-            Should contain default pinctrl.
+          minItems: 1
+
         pinctrl-1:
           description:
             Should switch CMD pin to GPIO mode as a high output.
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: mrvl,pxav3-mmc
+    then:
+      properties:
+        pinctrl-names:
+          description:
+            Optional for increasing stability of the controller at fast bus clocks.
+          items:
+            - const: default
+            - const: state_uhs
+          minItems: 1
+
+        pinctrl-1:
+          description:
+            Should switch the drive strength of the data pins to high.
 
 properties:
   compatible:
@@ -82,6 +99,14 @@ properties:
       - const: io
       - const: core
 
+  pinctrl-names: true
+
+  pinctrl-0:
+    description:
+      Should contain default pinctrl.
+
+  pinctrl-1: true
+
   mrvl,clk-delay-cycles:
     description: Specify a number of cycles to delay for tuning.
     $ref: /schemas/types.yaml#/definitions/uint32

drivers/memstick/core/memstick.c

@@ -370,7 +370,9 @@ int memstick_set_rw_addr(struct memstick_dev *card)
 {
 	card->next_request = h_memstick_set_rw_addr;
 	memstick_new_req(card->host);
-	wait_for_completion(&card->mrq_complete);
+	if (!wait_for_completion_timeout(&card->mrq_complete,
+			msecs_to_jiffies(500)))
+		card->current_mrq.error = -ETIMEDOUT;
 
 	return card->current_mrq.error;
 }
@@ -404,7 +406,9 @@ static struct memstick_dev *memstick_alloc_card(struct memstick_host *host)
 
 		card->next_request = h_memstick_read_dev_id;
 		memstick_new_req(host);
-		wait_for_completion(&card->mrq_complete);
+		if (!wait_for_completion_timeout(&card->mrq_complete,
+				msecs_to_jiffies(500)))
+			card->current_mrq.error = -ETIMEDOUT;
 
 		if (card->current_mrq.error)
 			goto err_out;

drivers/memstick/host/rtsx_usb_ms.c

@@ -216,7 +216,10 @@ static int ms_power_off(struct rtsx_usb_ms *host)
 
 	rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_CLK_EN, MS_CLK_EN, 0);
 	rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_OE, MS_OUTPUT_EN, 0);
-
+	rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_PWR_CTL,
+			POWER_MASK, POWER_OFF);
+	rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_PWR_CTL,
+			POWER_MASK | LDO3318_PWR_MASK, POWER_OFF | LDO_SUSPEND);
 	err = rtsx_usb_send_cmd(ucr, MODE_C, 100);
 	if (err < 0)
 		return err;

drivers/misc/cardreader/rtsx_usb.c

@@ -552,6 +552,10 @@ static int rtsx_usb_reset_chip(struct rtsx_ucr *ucr)
 	ret = rtsx_usb_send_cmd(ucr, MODE_C, 100);
 	if (ret)
 		return ret;
+	/* config OCP */
+	rtsx_usb_write_register(ucr, OCPCTL, MS_OCP_DETECT_EN, MS_OCP_DETECT_EN);
+	rtsx_usb_write_register(ucr, OCPPARA1, 0xF0, 0x50);
+	rtsx_usb_write_register(ucr, OCPPARA2, 0x7, 0x3);
 
 	/* config non-crystal mode */
 	rtsx_usb_read_register(ucr, CFG_MODE, &val);
@@ -722,6 +726,9 @@ static int rtsx_usb_suspend(struct usb_interface *intf, pm_message_t message)
 			if (val & (SD_CD | MS_CD)) {
 				device_for_each_child(&intf->dev, NULL, rtsx_usb_resume_child);
 				return -EAGAIN;
+			} else {
+				/* if the card does not exists, clear OCP status */
+				rtsx_usb_write_register(ucr, OCPCTL, MS_OCP_CLEAR, MS_OCP_CLEAR);
 			}
 		} else {
 			/* There is an ongoing operation*/

drivers/mmc/core/block.c

@@ -121,6 +121,10 @@ struct rpmb_frame {
 #define RPMB_READ_DATA         0x4    /* Read data from RPMB partition */
 #define RPMB_RESULT_READ       0x5    /* Read result request  (Internal) */
 
+#define RPMB_FRAME_SIZE        sizeof(struct rpmb_frame)
+#define CHECK_SIZE_NEQ(val) ((val) != sizeof(struct rpmb_frame))
+#define CHECK_SIZE_ALIGNED(val) IS_ALIGNED((val), sizeof(struct rpmb_frame))
+
 static DEFINE_MUTEX(block_mutex);
 
 /*
@@ -1768,8 +1772,7 @@ static void mmc_blk_rw_rq_prep(struct mmc_queue_req *mqrq,
 	 * these, while retaining features like reliable writes.
 	 */
 	if ((md->flags & MMC_BLK_CMD23) && mmc_op_multi(brq->cmd.opcode) &&
-	    (do_rel_wr || !(card->quirks & MMC_QUIRK_BLK_NO_CMD23) ||
-	     do_data_tag)) {
+	    (do_rel_wr || !mmc_card_blk_no_cmd23(card) || do_data_tag)) {
 		brq->sbc.opcode = MMC_SET_BLOCK_COUNT;
 		brq->sbc.arg = brq->data.blocks |
 			(do_rel_wr ? (1 << 31) : 0) |
@@ -2618,13 +2621,8 @@ static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card,
 	 */
 	md->read_only = mmc_blk_readonly(card);
 
-	if (mmc_host_can_cmd23(card->host)) {
-		if ((mmc_card_mmc(card) &&
-		     card->csd.mmca_vsn >= CSD_SPEC_VER_3) ||
-		    (mmc_card_sd(card) && !mmc_card_ult_capacity(card) &&
-		     card->scr.cmds & SD_SCR_CMD23_SUPPORT))
-			md->flags |= MMC_BLK_CMD23;
-	}
+	if (mmc_host_can_cmd23(card->host) && mmc_card_can_cmd23(card))
+		md->flags |= MMC_BLK_CMD23;
 
 	if (md->flags & MMC_BLK_CMD23 &&
 	    ((card->ext_csd.rel_param & EXT_CSD_WR_REL_PARAM_EN) ||
@@ -2864,12 +2862,12 @@ static void set_idata(struct mmc_blk_ioc_data *idata, u32 opcode,
 	 * The size of an RPMB frame must match what's expected by the
 	 * hardware.
 	 */
-	BUILD_BUG_ON(sizeof(struct rpmb_frame) != 512);
+	static_assert(!CHECK_SIZE_NEQ(512), "RPMB frame size must be 512 bytes");
 
 	idata->ic.opcode = opcode;
 	idata->ic.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
 	idata->ic.write_flag = write_flag;
-	idata->ic.blksz = sizeof(struct rpmb_frame);
+	idata->ic.blksz = RPMB_FRAME_SIZE;
 	idata->ic.blocks = buf_bytes /  idata->ic.blksz;
 	idata->buf = buf;
 	idata->buf_bytes = buf_bytes;
@@ -2893,32 +2891,28 @@ static int mmc_route_rpmb_frames(struct device *dev, u8 *req,
 	if (IS_ERR(md->queue.card))
 		return PTR_ERR(md->queue.card);
 
-	if (req_len < sizeof(*frm))
+	if (req_len < RPMB_FRAME_SIZE)
 		return -EINVAL;
 
 	req_type = be16_to_cpu(frm->req_resp);
 	switch (req_type) {
 	case RPMB_PROGRAM_KEY:
-		if (req_len != sizeof(struct rpmb_frame) ||
-		    resp_len != sizeof(struct rpmb_frame))
+		if (CHECK_SIZE_NEQ(req_len) || CHECK_SIZE_NEQ(resp_len))
 			return -EINVAL;
 		write = true;
 		break;
 	case RPMB_GET_WRITE_COUNTER:
-		if (req_len != sizeof(struct rpmb_frame) ||
-		    resp_len != sizeof(struct rpmb_frame))
+		if (CHECK_SIZE_NEQ(req_len) || CHECK_SIZE_NEQ(resp_len))
 			return -EINVAL;
 		write = false;
 		break;
 	case RPMB_WRITE_DATA:
-		if (req_len % sizeof(struct rpmb_frame) ||
-		    resp_len != sizeof(struct rpmb_frame))
+		if (!CHECK_SIZE_ALIGNED(req_len) || CHECK_SIZE_NEQ(resp_len))
 			return -EINVAL;
 		write = true;
 		break;
 	case RPMB_READ_DATA:
-		if (req_len != sizeof(struct rpmb_frame) ||
-		    resp_len % sizeof(struct rpmb_frame))
+		if (CHECK_SIZE_NEQ(req_len) || !CHECK_SIZE_ALIGNED(resp_len))
 			return -EINVAL;
 		write = false;
 		break;
@@ -2926,25 +2920,23 @@ static int mmc_route_rpmb_frames(struct device *dev, u8 *req,
 		return -EINVAL;
 	}
 
-	if (write)
-		cmd_count = 3;
-	else
-		cmd_count = 2;
+	/* Write operations require 3 commands, read operations require 2 */
+	cmd_count = write ? 3 : 2;
 
 	idata = alloc_idata(rpmb, cmd_count);
 	if (!idata)
 		return -ENOMEM;
 
 	if (write) {
-		struct rpmb_frame *frm = (struct rpmb_frame *)resp;
+		struct rpmb_frame *resp_frm = (struct rpmb_frame *)resp;
 
 		/* Send write request frame(s) */
 		set_idata(idata[0], MMC_WRITE_MULTIPLE_BLOCK,
 			  1 | MMC_CMD23_ARG_REL_WR, req, req_len);
 
 		/* Send result request frame */
-		memset(frm, 0, sizeof(*frm));
-		frm->req_resp = cpu_to_be16(RPMB_RESULT_READ);
+		memset(resp_frm, 0, RPMB_FRAME_SIZE);
+		resp_frm->req_resp = cpu_to_be16(RPMB_RESULT_READ);
 		set_idata(idata[1], MMC_WRITE_MULTIPLE_BLOCK, 1, resp,
 			  resp_len);
 

drivers/mmc/core/bus.c

@@ -19,6 +19,7 @@
 
 #include <linux/mmc/card.h>
 #include <linux/mmc/host.h>
+#include <linux/mmc/mmc.h>
 
 #include "core.h"
 #include "card.h"
@@ -383,6 +384,14 @@ int mmc_add_card(struct mmc_card *card)
 
 	mmc_card_set_present(card);
 
+	/*
+	 * Register for undervoltage notification if the card supports
+	 * power-off notification, enabling emergency shutdowns.
+	 */
+	if (mmc_card_mmc(card) &&
+	    card->ext_csd.power_off_notification == EXT_CSD_POWER_ON)
+		mmc_regulator_register_undervoltage_notifier(card->host);
+
 	return 0;
 }
 
@@ -394,6 +403,9 @@ void mmc_remove_card(struct mmc_card *card)
 {
 	struct mmc_host *host = card->host;
 
+	if (mmc_card_present(card))
+		mmc_regulator_unregister_undervoltage_notifier(host);
+
 	mmc_remove_card_debugfs(card);
 
 	if (mmc_card_present(card)) {

drivers/mmc/core/card.h

@@ -245,14 +245,19 @@ static inline int mmc_blksz_for_byte_mode(const struct mmc_card *c)
 	return c->quirks & MMC_QUIRK_BLKSZ_FOR_BYTE_MODE;
 }
 
+static inline int mmc_card_nonstd_func_interface(const struct mmc_card *c)
+{
+	return c->quirks & MMC_QUIRK_NONSTD_FUNC_IF;
+}
+
 static inline int mmc_card_disable_cd(const struct mmc_card *c)
 {
 	return c->quirks & MMC_QUIRK_DISABLE_CD;
 }
 
-static inline int mmc_card_nonstd_func_interface(const struct mmc_card *c)
+static inline int mmc_card_blk_no_cmd23(const struct mmc_card *c)
 {
-	return c->quirks & MMC_QUIRK_NONSTD_FUNC_IF;
+	return c->quirks & MMC_QUIRK_BLK_NO_CMD23;
 }
 
 static inline int mmc_card_broken_byte_mode_512(const struct mmc_card *c)

drivers/mmc/core/core.c

@@ -1398,6 +1398,29 @@ void mmc_power_cycle(struct mmc_host *host, u32 ocr)
 	mmc_power_up(host, ocr);
 }
 
+/**
+ * mmc_handle_undervoltage - Handle an undervoltage event on the MMC bus
+ * @host: The MMC host that detected the undervoltage condition
+ *
+ * This function is called when an undervoltage event is detected on one of
+ * the MMC regulators.
+ *
+ * Returns: 0 on success or a negative error code on failure.
+ */
+int mmc_handle_undervoltage(struct mmc_host *host)
+{
+	/* Stop the host to prevent races with card removal */
+	__mmc_stop_host(host);
+
+	if (!host->bus_ops || !host->bus_ops->handle_undervoltage)
+		return 0;
+
+	dev_warn(mmc_dev(host), "%s: Undervoltage detected, initiating emergency stop\n",
+		 mmc_hostname(host));
+
+	return host->bus_ops->handle_undervoltage(host);
+}
+
 /*
  * Assign a mmc bus handler to a host. Only one bus handler may control a
  * host at any given time.
@@ -1875,6 +1898,15 @@ bool mmc_card_can_secure_erase_trim(struct mmc_card *card)
 }
 EXPORT_SYMBOL(mmc_card_can_secure_erase_trim);
 
+bool mmc_card_can_cmd23(struct mmc_card *card)
+{
+	return ((mmc_card_mmc(card) &&
+		 card->csd.mmca_vsn >= CSD_SPEC_VER_3) ||
+		(mmc_card_sd(card) && !mmc_card_ult_capacity(card) &&
+		 card->scr.cmds & SD_SCR_CMD23_SUPPORT));
+}
+EXPORT_SYMBOL(mmc_card_can_cmd23);
+
 int mmc_erase_group_aligned(struct mmc_card *card, sector_t from,
 			    unsigned int nr)
 {

drivers/mmc/core/core.h

@@ -31,6 +31,7 @@ struct mmc_bus_ops {
 	int (*sw_reset)(struct mmc_host *);
 	bool (*cache_enabled)(struct mmc_host *);
 	int (*flush_cache)(struct mmc_host *);
+	int (*handle_undervoltage)(struct mmc_host *host);
 };
 
 void mmc_attach_bus(struct mmc_host *host, const struct mmc_bus_ops *ops);
@@ -59,6 +60,10 @@ void mmc_power_off(struct mmc_host *host);
 void mmc_power_cycle(struct mmc_host *host, u32 ocr);
 void mmc_set_initial_state(struct mmc_host *host);
 u32 mmc_vddrange_to_ocrmask(int vdd_min, int vdd_max);
+int mmc_handle_undervoltage(struct mmc_host *host);
+void mmc_regulator_register_undervoltage_notifier(struct mmc_host *host);
+void mmc_regulator_unregister_undervoltage_notifier(struct mmc_host *host);
+void mmc_undervoltage_workfn(struct work_struct *work);
 
 static inline void mmc_delay(unsigned int ms)
 {
@@ -123,6 +128,7 @@ bool mmc_card_can_trim(struct mmc_card *card);
 bool mmc_card_can_discard(struct mmc_card *card);
 bool mmc_card_can_sanitize(struct mmc_card *card);
 bool mmc_card_can_secure_erase_trim(struct mmc_card *card);
+bool mmc_card_can_cmd23(struct mmc_card *card);
 int mmc_erase_group_aligned(struct mmc_card *card, sector_t from, unsigned int nr);
 unsigned int mmc_calc_max_discard(struct mmc_card *card);
 

drivers/mmc/core/host.c

@@ -302,6 +302,8 @@ int mmc_of_parse(struct mmc_host *host)
 	/* f_max is obtained from the optional "max-frequency" property */
 	device_property_read_u32(dev, "max-frequency", &host->f_max);
 
+	device_property_read_u32(dev, "max-sd-hs-hz", &host->max_sd_hs_hz);
+
 	/*
 	 * Configure CD and WP pins. They are both by default active low to
 	 * match the SDHCI spec. If GPIOs are provided for CD and / or WP, the
@@ -564,6 +566,8 @@ struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
 	INIT_WORK(&host->sdio_irq_work, sdio_irq_work);
 	timer_setup(&host->retune_timer, mmc_retune_timer, 0);
 
+	INIT_WORK(&host->supply.uv_work, mmc_undervoltage_workfn);
+
 	/*
 	 * By default, hosts do not support SGIO or large requests.
 	 * They have to set these according to their abilities.

drivers/mmc/core/mmc.c

@@ -36,6 +36,7 @@
 enum mmc_poweroff_type {
 	MMC_POWEROFF_SUSPEND,
 	MMC_POWEROFF_SHUTDOWN,
+	MMC_POWEROFF_UNDERVOLTAGE,
 	MMC_POWEROFF_UNBIND,
 };
 
@@ -2132,9 +2133,15 @@ static int _mmc_suspend(struct mmc_host *host, enum mmc_poweroff_type pm_type)
 	if (mmc_card_suspended(host->card))
 		goto out;
 
-	err = _mmc_flush_cache(host);
-	if (err)
-		goto out;
+	/*
+	 * For the undervoltage case, we care more about device integrity.
+	 * Avoid cache flush and notify the device to power off quickly.
+	 */
+	if (pm_type != MMC_POWEROFF_UNDERVOLTAGE) {
+		err = _mmc_flush_cache(host);
+		if (err)
+			goto out;
+	}
 
 	if (mmc_card_can_poweroff_notify(host->card) &&
 	    mmc_host_can_poweroff_notify(host, pm_type))
@@ -2212,6 +2219,13 @@ static int mmc_shutdown(struct mmc_host *host)
 {
 	int err = 0;
 
+	/*
+	 * In case of undervoltage, the card will be powered off (removed) by
+	 * _mmc_handle_undervoltage()
+	 */
+	if (mmc_card_removed(host->card))
+		return 0;
+
 	/*
 	 * If the card remains suspended at this point and it was done by using
 	 * the sleep-cmd (CMD5), we may need to re-initialize it first, to allow
@@ -2302,6 +2316,55 @@ static int _mmc_hw_reset(struct mmc_host *host)
 	return mmc_init_card(host, card->ocr, card);
 }
 
+/**
+ * _mmc_handle_undervoltage - Handle an undervoltage event for MMC/eMMC devices
+ * @host: MMC host structure
+ *
+ * This function is triggered when an undervoltage condition is detected.
+ * It attempts to transition the device into a low-power or safe state to
+ * prevent data corruption.
+ *
+ * Steps performed:
+ * - Perform an emergency suspend using EXT_CSD_POWER_OFF_SHORT if possible.
+ *    - If power-off notify is not supported, fallback mechanisms like sleep or
+ *      deselecting the card are attempted.
+ *    - Cache flushing is skipped to reduce execution time.
+ * - Mark the card as removed to prevent further interactions after
+ *    undervoltage.
+ *
+ * Note: This function does not handle host claiming or releasing. The caller
+ *	 must ensure that the host is properly claimed before calling this
+ *	 function and released afterward.
+ *
+ * Returns: 0 on success, or a negative error code if any step fails.
+ */
+static int _mmc_handle_undervoltage(struct mmc_host *host)
+{
+	struct mmc_card *card = host->card;
+	int err;
+
+	/*
+	 * Perform an emergency suspend to power off the eMMC quickly.
+	 * This ensures the device enters a safe state before power is lost.
+	 * We first attempt EXT_CSD_POWER_OFF_SHORT, but if power-off notify
+	 * is not supported, we fall back to sleep mode or deselecting the card.
+	 * Cache flushing is skipped to minimize delay.
+	 */
+	err = _mmc_suspend(host, MMC_POWEROFF_UNDERVOLTAGE);
+	if (err)
+		pr_err("%s: undervoltage suspend failed: %pe\n",
+		       mmc_hostname(host), ERR_PTR(err));
+
+	/*
+	 * Mark the card as removed to prevent further operations.
+	 * This ensures the system does not attempt to access the device
+	 * after an undervoltage event, avoiding potential corruption.
+	 */
+	mmc_card_set_removed(card);
+
+	return err;
+}
+
 static const struct mmc_bus_ops mmc_ops = {
 	.remove = mmc_remove,
 	.detect = mmc_detect,
@@ -2314,6 +2377,7 @@ static const struct mmc_bus_ops mmc_ops = {
 	.hw_reset = _mmc_hw_reset,
 	.cache_enabled = _mmc_cache_enabled,
 	.flush_cache = _mmc_flush_cache,
+	.handle_undervoltage = _mmc_handle_undervoltage,
 };
 
 /*

drivers/mmc/core/mmc_ops.c

@@ -1077,3 +1077,75 @@ int mmc_sanitize(struct mmc_card *card, unsigned int timeout_ms)
 	return err;
 }
 EXPORT_SYMBOL_GPL(mmc_sanitize);
+
+/**
+ * mmc_read_tuning() - read data blocks from the mmc
+ * @host: mmc host doing the read
+ * @blksz: data block size
+ * @blocks: number of blocks to read
+ *
+ * Read one or more blocks of data from the beginning of the mmc. This is a
+ * low-level helper for tuning operation. It is assumed that CMD23 can be used
+ * for multi-block read if the host supports it.
+ *
+ * Note: Allocate and free a temporary buffer to store the data read. The data
+ * is not available outside of the function, only the status of the read
+ * operation.
+ *
+ * Return: 0 in case of success, otherwise -EIO / -ENOMEM / -E2BIG
+ */
+int mmc_read_tuning(struct mmc_host *host, unsigned int blksz, unsigned int blocks)
+{
+	struct mmc_request mrq = {};
+	struct mmc_command sbc = {};
+	struct mmc_command cmd = {};
+	struct mmc_command stop = {};
+	struct mmc_data data = {};
+	struct scatterlist sg;
+	void *buf;
+	unsigned int len;
+
+	if (blocks > 1) {
+		if (mmc_host_can_cmd23(host)) {
+			mrq.sbc = &sbc;
+			sbc.opcode = MMC_SET_BLOCK_COUNT;
+			sbc.arg = blocks;
+			sbc.flags = MMC_RSP_R1 | MMC_CMD_AC;
+		}
+		cmd.opcode = MMC_READ_MULTIPLE_BLOCK;
+		mrq.stop = &stop;
+		stop.opcode = MMC_STOP_TRANSMISSION;
+		stop.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC;
+	} else {
+		cmd.opcode = MMC_READ_SINGLE_BLOCK;
+	}
+
+	mrq.cmd = &cmd;
+	cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;
+
+	mrq.data = &data;
+	data.flags = MMC_DATA_READ;
+	data.blksz = blksz;
+	data.blocks = blocks;
+	data.blk_addr = 0;
+	data.sg = &sg;
+	data.sg_len = 1;
+	data.timeout_ns = 1000000000;
+
+	if (check_mul_overflow(blksz, blocks, &len))
+		return -E2BIG;
+	buf = kmalloc(len, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	sg_init_one(&sg, buf, len);
+
+	mmc_wait_for_req(host, &mrq);
+	kfree(buf);
+
+	if (sbc.error || cmd.error || data.error)
+		return -EIO;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(mmc_read_tuning);

drivers/mmc/core/mmc_test.c

@@ -180,20 +180,14 @@ static int mmc_test_set_blksize(struct mmc_test_card *test, unsigned size)
 	return mmc_set_blocklen(test->card, size);
 }
 
-static bool mmc_test_card_cmd23(struct mmc_card *card)
-{
-	return mmc_card_mmc(card) ||
-	       (mmc_card_sd(card) && card->scr.cmds & SD_SCR_CMD23_SUPPORT);
-}
-
 static void mmc_test_prepare_sbc(struct mmc_test_card *test,
 				 struct mmc_request *mrq, unsigned int blocks)
 {
 	struct mmc_card *card = test->card;
 
 	if (!mrq->sbc || !mmc_host_can_cmd23(card->host) ||
-	    !mmc_test_card_cmd23(card) || !mmc_op_multi(mrq->cmd->opcode) ||
-	    (card->quirks & MMC_QUIRK_BLK_NO_CMD23)) {
+	    !mmc_card_can_cmd23(card) || !mmc_op_multi(mrq->cmd->opcode) ||
+	    mmc_card_blk_no_cmd23(card)) {
 		mrq->sbc = NULL;
 		return;
 	}

drivers/mmc/core/regulator.c

@@ -7,6 +7,7 @@
 #include <linux/err.h>
 #include <linux/log2.h>
 #include <linux/regulator/consumer.h>
+#include <linux/workqueue.h>
 
 #include <linux/mmc/host.h>
 
@@ -262,6 +263,82 @@ static inline int mmc_regulator_get_ocrmask(struct regulator *supply)
 
 #endif /* CONFIG_REGULATOR */
 
+/* To be called from a high-priority workqueue */
+void mmc_undervoltage_workfn(struct work_struct *work)
+{
+	struct mmc_supply *supply;
+	struct mmc_host *host;
+
+	supply = container_of(work, struct mmc_supply, uv_work);
+	host = container_of(supply, struct mmc_host, supply);
+
+	mmc_handle_undervoltage(host);
+}
+
+static int mmc_handle_regulator_event(struct notifier_block *nb,
+				      unsigned long event, void *data)
+{
+	struct mmc_supply *supply = container_of(nb, struct mmc_supply,
+						 vmmc_nb);
+	struct mmc_host *host = container_of(supply, struct mmc_host, supply);
+	unsigned long flags;
+
+	switch (event) {
+	case REGULATOR_EVENT_UNDER_VOLTAGE:
+		spin_lock_irqsave(&host->lock, flags);
+		if (host->undervoltage) {
+			spin_unlock_irqrestore(&host->lock, flags);
+			return NOTIFY_OK;
+		}
+
+		host->undervoltage = true;
+		spin_unlock_irqrestore(&host->lock, flags);
+
+		queue_work(system_highpri_wq, &host->supply.uv_work);
+		break;
+	default:
+		return NOTIFY_DONE;
+	}
+
+	return NOTIFY_OK;
+}
+
+/**
+ * mmc_regulator_register_undervoltage_notifier - Register for undervoltage
+ *						  events
+ * @host: MMC host
+ *
+ * To be called by a bus driver when a card supporting graceful shutdown
+ * is attached.
+ */
+void mmc_regulator_register_undervoltage_notifier(struct mmc_host *host)
+{
+	int ret;
+
+	if (IS_ERR_OR_NULL(host->supply.vmmc))
+		return;
+
+	host->supply.vmmc_nb.notifier_call = mmc_handle_regulator_event;
+	ret = regulator_register_notifier(host->supply.vmmc,
+					  &host->supply.vmmc_nb);
+	if (ret)
+		dev_warn(mmc_dev(host), "Failed to register vmmc notifier: %d\n", ret);
+}
+
+/**
+ * mmc_regulator_unregister_undervoltage_notifier - Unregister undervoltage
+ *						    notifier
+ * @host: MMC host
+ */
+void mmc_regulator_unregister_undervoltage_notifier(struct mmc_host *host)
+{
+	if (IS_ERR_OR_NULL(host->supply.vmmc))
+		return;
+
+	regulator_unregister_notifier(host->supply.vmmc, &host->supply.vmmc_nb);
+	cancel_work_sync(&host->supply.uv_work);
+}
+
 /**
  * mmc_regulator_get_supply - try to get VMMC and VQMMC regulators for a host
  * @mmc: the host to regulate

drivers/mmc/core/sd.c

@@ -359,7 +359,7 @@ static int mmc_read_switch(struct mmc_card *card)
 	}
 
 	if (status[13] & SD_MODE_HIGH_SPEED)
-		card->sw_caps.hs_max_dtr = HIGH_SPEED_MAX_DTR;
+		card->sw_caps.hs_max_dtr = card->host->max_sd_hs_hz ?: HIGH_SPEED_MAX_DTR;
 
 	if (card->scr.sda_spec3) {
 		card->sw_caps.sd3_bus_mode = status[13];

drivers/mmc/core/sdio.c

@@ -945,7 +945,11 @@ static void mmc_sdio_remove(struct mmc_host *host)
  */
 static int mmc_sdio_alive(struct mmc_host *host)
 {
-	return mmc_select_card(host->card);
+	if (!mmc_host_is_spi(host))
+		return mmc_select_card(host->card);
+	else
+		return mmc_io_rw_direct(host->card, 0, 0, SDIO_CCCR_CCCR, 0,
+					NULL);
 }
 
 /*