[v2,1/2] scsi: ufs: Probe for temperature notification support

Commit Message

Avri Altman Sept. 9, 2021, 6:34 a.m. UTC

Probe the dExtendedUFSFeaturesSupport register for the device's
temperature notification support, and if supported, add a hw monitor
device.

Signed-off-by: Avri Altman <[e-mail]>
---
 drivers/scsi/ufs/Kconfig     |  10 ++
 drivers/scsi/ufs/Makefile    |   1 +
 drivers/scsi/ufs/ufs-hwmon.c | 180 +++++++++++++++++++++++++++++++++++
 drivers/scsi/ufs/ufs.h       |   6 ++
 drivers/scsi/ufs/ufshcd.c    |  27 ++++++
 drivers/scsi/ufs/ufshcd.h    |  18 ++++
 6 files changed, 242 insertions(+)
 create mode 100644 drivers/scsi/ufs/ufs-hwmon.c

Comments

Bart Van Assche Sept. 9, 2021, 4:26 p.m. UTC | #1

On 9/8/21 11:34 PM, Avri Altman wrote:
> +static bool ufs_temp_enabled(struct ufs_hba *hba, struct ufs_hwmon_data *data)
> +{
> +	u32 ee_mask;
> +
> +	if (ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_READ_ATTR,
> +			      QUERY_ATTR_IDN_EE_CONTROL, 0, 0, &ee_mask))
> +		return false;
> +
> +	return (data->mask & ee_mask & MASK_EE_TOO_HIGH_TEMP) ||
> +		(data->mask & ee_mask & MASK_EE_TOO_LOW_TEMP);
> +}

The above function uses data->mask but not data so it's probably better to pass
data->mask directly as the second argument.

> +static bool ufs_temp_valid(struct ufs_hba *hba, struct ufs_hwmon_data *data,
> +			   enum attr_idn idn, u32 value)
> +{
> +	return (idn == QUERY_ATTR_IDN_CASE_ROUGH_TEMP && value >= 1 &&
> +		value <= 250 && ufs_temp_enabled(hba, data)) ||
> +	      (idn == QUERY_ATTR_IDN_HIGH_TEMP_BOUND && value >= 100 &&
> +	       value <= 250) ||
> +	      (idn == QUERY_ATTR_IDN_LOW_TEMP_BOUND && value >= 1 &&
> +	       value <= 80);
> +}

Same comment for this function - if the above comment is addressed 'mask' can be
passed as an argument instead of 'data'.

> +static int ufs_get_temp(struct ufs_hba *hba, struct ufs_hwmon_data *data,
> +			enum attr_idn idn)
> +{
> +	u32 value;
> +
> +	if (ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_READ_ATTR, idn, 0, 0,
> +	    &value))
> +		return 0;
> +
> +	if (ufs_temp_valid(hba, data, idn, value))
> +		return value - 80;
> +
> +	return 0;
> +}

Same comment here.

> +void ufs_hwmon_remove(struct ufs_hba *hba)
> +{
> +	if (hba->hwmon_device) {
> +		struct ufs_hwmon_data *data =
> +			dev_get_drvdata(hba->hwmon_device);
> +
> +		hwmon_device_unregister(hba->hwmon_device);
> +		hba->hwmon_device = NULL;
> +		kfree(data);
> +	}
> +}

Please use the "early return" style since that is the most widely used style
in the Linux kernel (if (!hba->hwmon_device) return).

Thanks,

Bart.

Guenter Roeck Sept. 9, 2021, 4:51 p.m. UTC | #2

On Thu, Sep 09, 2021 at 09:34:43AM +0300, Avri Altman wrote:
> Probe the dExtendedUFSFeaturesSupport register for the device's
> temperature notification support, and if supported, add a hw monitor
> device.
> 
> Signed-off-by: Avri Altman <[e-mail]>
> ---
>  drivers/scsi/ufs/Kconfig     |  10 ++
>  drivers/scsi/ufs/Makefile    |   1 +
>  drivers/scsi/ufs/ufs-hwmon.c | 180 +++++++++++++++++++++++++++++++++++
>  drivers/scsi/ufs/ufs.h       |   6 ++
>  drivers/scsi/ufs/ufshcd.c    |  27 ++++++
>  drivers/scsi/ufs/ufshcd.h    |  18 ++++
>  6 files changed, 242 insertions(+)
>  create mode 100644 drivers/scsi/ufs/ufs-hwmon.c
> 
> diff --git a/drivers/scsi/ufs/Kconfig b/drivers/scsi/ufs/Kconfig
> index 432df76e6318..b930f29fc375 100644
> --- a/drivers/scsi/ufs/Kconfig
> +++ b/drivers/scsi/ufs/Kconfig
> @@ -199,3 +199,13 @@ config SCSI_UFS_FAULT_INJECTION
>  	help
>  	  Enable fault injection support in the UFS driver. This makes it easier
>  	  to test the UFS error handler and abort handler.
> +
> +config SCSI_UFS_HWMON
> +	bool "UFS  Temperature Notification"
> +	depends on SCSI_UFSHCD && HWMON
> +	help
> +	  This provides support for UFS hardware monitoring. If enabled,
> +	  a hardware monitoring device will be created for the UFS device.
> +
> +	  If unsure, say N.
> +
> diff --git a/drivers/scsi/ufs/Makefile b/drivers/scsi/ufs/Makefile
> index c407da9b5171..966048875b50 100644
> --- a/drivers/scsi/ufs/Makefile
> +++ b/drivers/scsi/ufs/Makefile
> @@ -10,6 +10,7 @@ ufshcd-core-$(CONFIG_SCSI_UFS_BSG)	+= ufs_bsg.o
>  ufshcd-core-$(CONFIG_SCSI_UFS_CRYPTO)	+= ufshcd-crypto.o
>  ufshcd-core-$(CONFIG_SCSI_UFS_HPB)	+= ufshpb.o
>  ufshcd-core-$(CONFIG_SCSI_UFS_FAULT_INJECTION) += ufs-fault-injection.o
> +ufshcd-core-$(CONFIG_SCSI_UFS_HWMON) += ufs-hwmon.o
>  
>  obj-$(CONFIG_SCSI_UFS_DWC_TC_PCI) += tc-dwc-g210-pci.o ufshcd-dwc.o tc-dwc-g210.o
>  obj-$(CONFIG_SCSI_UFS_DWC_TC_PLATFORM) += tc-dwc-g210-pltfrm.o ufshcd-dwc.o tc-dwc-g210.o
> diff --git a/drivers/scsi/ufs/ufs-hwmon.c b/drivers/scsi/ufs/ufs-hwmon.c
> new file mode 100644
> index 000000000000..159678ce89ce
> --- /dev/null
> +++ b/drivers/scsi/ufs/ufs-hwmon.c
> @@ -0,0 +1,180 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * UFS hardware monitoring support
> + * Copyright (c) 2021, Western Digital Corporation
> + */
> +
> +#include <linux/hwmon.h>
> +
> +#include "ufshcd.h"
> +
> +struct ufs_hwmon_data {
> +	struct ufs_hba *hba;
> +	u8 mask;
> +};
> +
> +static bool ufs_temp_enabled(struct ufs_hba *hba, struct ufs_hwmon_data *data)
> +{
> +	u32 ee_mask;
> +
> +	if (ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_READ_ATTR,
> +			      QUERY_ATTR_IDN_EE_CONTROL, 0, 0, &ee_mask))
> +		return false;
> +
> +	return (data->mask & ee_mask & MASK_EE_TOO_HIGH_TEMP) ||
> +		(data->mask & ee_mask & MASK_EE_TOO_LOW_TEMP);
> +}
> +
> +static bool ufs_temp_valid(struct ufs_hba *hba, struct ufs_hwmon_data *data,
> +			   enum attr_idn idn, u32 value)
> +{
> +	return (idn == QUERY_ATTR_IDN_CASE_ROUGH_TEMP && value >= 1 &&
> +		value <= 250 && ufs_temp_enabled(hba, data)) ||
> +	      (idn == QUERY_ATTR_IDN_HIGH_TEMP_BOUND && value >= 100 &&
> +	       value <= 250) ||
> +	      (idn == QUERY_ATTR_IDN_LOW_TEMP_BOUND && value >= 1 &&
> +	       value <= 80);
> +}
> +
> +static int ufs_get_temp(struct ufs_hba *hba, struct ufs_hwmon_data *data,
> +			enum attr_idn idn)
> +{
> +	u32 value;
> +
> +	if (ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_READ_ATTR, idn, 0, 0,
> +	    &value))
> +		return 0;
> +
> +	if (ufs_temp_valid(hba, data, idn, value))
> +		return value - 80;
> +
> +	return 0;
> +}
> +
> +static int ufs_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
> +			   u32 attr, int channel, long *val)
> +{
> +	struct ufs_hwmon_data *data = dev_get_drvdata(dev);
> +	struct ufs_hba *hba = data->hba;
> +	int err = 0;
> +	bool get_temp = true;
> +
> +	if (type != hwmon_temp)
> +		return 0;
> +
> +	down(&hba->host_sem);
> +
> +	if (!ufshcd_is_user_access_allowed(hba)) {
> +		up(&hba->host_sem);
> +		return -EBUSY;
> +	}
> +
> +	ufshcd_rpm_get_sync(hba);
> +
> +	switch (attr) {
> +	case hwmon_temp_enable:
> +		*val = ufs_temp_enabled(hba, data);
> +		get_temp = false;
> +
> +		break;
> +	case hwmon_temp_max_alarm:
> +		*val = ufs_get_temp(hba, data, QUERY_ATTR_IDN_HIGH_TEMP_BOUND);
> +
> +		break;
> +	case hwmon_temp_min_alarm:
> +		*val = ufs_get_temp(hba, data, QUERY_ATTR_IDN_LOW_TEMP_BOUND);
> +
> +		break;
> +	case hwmon_temp_input:
> +		*val = ufs_get_temp(hba, data, QUERY_ATTR_IDN_CASE_ROUGH_TEMP);
> +
> +		break;
> +	default:
> +		err = -EOPNOTSUPP;
> +
> +		break;
> +	}
> +
> +	ufshcd_rpm_put_sync(hba);
> +
> +	up(&hba->host_sem);
> +
> +	if (get_temp && !err && *val == 0)
> +		err = -EINVAL;
> +
> +	return err;
> +}
> +
> +static umode_t ufs_hwmon_is_visible(const void *_data,
> +				     enum hwmon_sensor_types type,
> +				     u32 attr, int channel)
> +{
> +	if (type != hwmon_temp)
> +		return 0;
> +
> +	switch (attr) {
> +	case hwmon_temp_enable:
> +	case hwmon_temp_max_alarm:
> +	case hwmon_temp_min_alarm:
> +	case hwmon_temp_input:
> +		return 0444;
> +	default:
> +		break;
> +	}
> +	return 0;
> +}
> +
> +static const struct hwmon_channel_info *ufs_hwmon_info[] = {
> +	HWMON_CHANNEL_INFO(temp, HWMON_T_ENABLE | HWMON_T_INPUT |
> +			    HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM),
> +	NULL
> +};
> +
> +static const struct hwmon_ops ufs_hwmon_ops = {
> +	.is_visible	= ufs_hwmon_is_visible,
> +	.read		= ufs_hwmon_read,
> +};
> +
> +static const struct hwmon_chip_info ufs_hwmon_hba_info = {
> +	.ops	= &ufs_hwmon_ops,
> +	.info	= ufs_hwmon_info,
> +};
> +
> +int ufs_hwmon_probe(struct ufs_hba *hba, u8 mask)
> +{
> +	struct device *dev = hba->dev;
> +	struct ufs_hwmon_data *data;
> +	struct device *hwmon;
> +
> +	data = kzalloc(sizeof(*data), GFP_KERNEL);
> +	if (!data)
> +		return 0;
> +
> +	data->hba = hba;
> +	data->mask = mask;
> +
> +	hwmon = hwmon_device_register_with_info(dev, "ufs",
> +						data, &ufs_hwmon_hba_info,
> +						NULL);
> +	if (IS_ERR(hwmon)) {
> +		dev_warn(dev, "Failed to instantiate hwmon device\n");
> +		kfree(data);
> +		return PTR_ERR(hwmon);

If the error is ignored by the caller, it doesn't make sense
to return it.

> +	}
> +
> +	hba->hwmon_device = hwmon;
> +
> +	return 0;
> +}
> +
> +void ufs_hwmon_remove(struct ufs_hba *hba)
> +{
> +	if (hba->hwmon_device) {
> +		struct ufs_hwmon_data *data =
> +			dev_get_drvdata(hba->hwmon_device);
> +
> +		hwmon_device_unregister(hba->hwmon_device);
> +		hba->hwmon_device = NULL;
> +		kfree(data);
> +	}
> +}

That function is never called and thus pointless (suggesting that there may be 
some structural problem in the code).

> diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h
> index 8c6b38b1b142..171b27be7b1d 100644
> --- a/drivers/scsi/ufs/ufs.h
> +++ b/drivers/scsi/ufs/ufs.h
> @@ -152,6 +152,9 @@ enum attr_idn {
>  	QUERY_ATTR_IDN_PSA_STATE		= 0x15,
>  	QUERY_ATTR_IDN_PSA_DATA_SIZE		= 0x16,
>  	QUERY_ATTR_IDN_REF_CLK_GATING_WAIT_TIME	= 0x17,
> +	QUERY_ATTR_IDN_CASE_ROUGH_TEMP          = 0x18,
> +	QUERY_ATTR_IDN_HIGH_TEMP_BOUND          = 0x19,
> +	QUERY_ATTR_IDN_LOW_TEMP_BOUND           = 0x1A,
>  	QUERY_ATTR_IDN_WB_FLUSH_STATUS	        = 0x1C,
>  	QUERY_ATTR_IDN_AVAIL_WB_BUFF_SIZE       = 0x1D,
>  	QUERY_ATTR_IDN_WB_BUFF_LIFE_TIME_EST    = 0x1E,
> @@ -338,6 +341,9 @@ enum {
>  
>  /* Possible values for dExtendedUFSFeaturesSupport */
>  enum {
> +	UFS_DEV_LOW_TEMP_NOTIF		= BIT(4),
> +	UFS_DEV_HIGH_TEMP_NOTIF		= BIT(5),
> +	UFS_DEV_EXT_TEMP_NOTIF		= BIT(6),
>  	UFS_DEV_HPB_SUPPORT		= BIT(7),
>  	UFS_DEV_WRITE_BOOSTER_SUP	= BIT(8),
>  };
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 3841ab49f556..fc995bf1f296 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -7469,6 +7469,31 @@ static void ufshcd_wb_probe(struct ufs_hba *hba, u8 *desc_buf)
>  	hba->caps &= ~UFSHCD_CAP_WB_EN;
>  }
>  
> +static void ufshcd_temp_notif_probe(struct ufs_hba *hba, u8 *desc_buf)
> +{
> +	struct ufs_dev_info *dev_info = &hba->dev_info;
> +	u32 ext_ufs_feature;
> +	u8 mask = 0;
> +
> +	if (!(hba->caps & UFSHCD_CAP_TEMP_NOTIF) ||
> +	    dev_info->wspecversion < 0x300)
> +		return;
> +
> +	ext_ufs_feature = get_unaligned_be32(desc_buf +
> +					DEVICE_DESC_PARAM_EXT_UFS_FEATURE_SUP);
> +
> +	if (ext_ufs_feature & UFS_DEV_LOW_TEMP_NOTIF)
> +		mask |= MASK_EE_TOO_LOW_TEMP;
> +
> +	if (ext_ufs_feature & UFS_DEV_HIGH_TEMP_NOTIF)
> +		mask |= MASK_EE_TOO_HIGH_TEMP;
> +
> +	if (mask) {
> +		ufshcd_enable_ee(hba, mask);
> +		ufs_hwmon_probe(hba, mask);
> +	}
> +}
> +
>  void ufshcd_fixup_dev_quirks(struct ufs_hba *hba, struct ufs_dev_fix *fixups)
>  {
>  	struct ufs_dev_fix *f;
> @@ -7564,6 +7589,8 @@ static int ufs_get_device_desc(struct ufs_hba *hba)
>  
>  	ufshcd_wb_probe(hba, desc_buf);
>  
> +	ufshcd_temp_notif_probe(hba, desc_buf);
> +

Is that the appropriate place to make this call ?

>  	/*
>  	 * ufshcd_read_string_desc returns size of the string
>  	 * reset the error value
> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> index 52ea6f350b18..9bc434c4ae71 100644
> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@ -653,6 +653,12 @@ enum ufshcd_caps {
>  	 * in order to exit DeepSleep state.
>  	 */
>  	UFSHCD_CAP_DEEPSLEEP				= 1 << 10,
> +
> +	/*
> +	 * This capability allows the host controller driver to use temperature
> +	 * notification if it is supported by the UFS device.
> +	 */
> +	UFSHCD_CAP_TEMP_NOTIF				= 1 << 11,
>  };
>  
>  struct ufs_hba_variant_params {
> @@ -789,6 +795,10 @@ struct ufs_hba {
>  	struct scsi_device *sdev_ufs_device;
>  	struct scsi_device *sdev_rpmb;
>  
> +#ifdef CONFIG_SCSI_UFS_HWMON
> +	struct device *hwmon_device;
> +#endif
> +
>  	enum ufs_dev_pwr_mode curr_dev_pwr_mode;
>  	enum uic_link_state uic_link_state;
>  	/* Desired UFS power management level during runtime PM */
> @@ -1049,6 +1059,14 @@ static inline u8 ufshcd_wb_get_query_index(struct ufs_hba *hba)
>  	return 0;
>  }
>  
> +#ifdef CONFIG_SCSI_UFS_HWMON
> +int ufs_hwmon_probe(struct ufs_hba *hba, u8 mask);
> +void ufs_hwmon_remove(struct ufs_hba *hba);
> +#else
> +static inline int ufs_hwmon_probe(struct ufs_hba *hba, u8 mask) { return 0; }
> +static inline void nvme_hwmon_remove(struct ufs_hba *hba) {}

ufs_hwmon_remove

> +#endif
> +
>  #ifdef CONFIG_PM
>  extern int ufshcd_runtime_suspend(struct device *dev);
>  extern int ufshcd_runtime_resume(struct device *dev);
> -- 
> 2.17.1
>

Avri Altman Sept. 10, 2021, 3:58 p.m. UTC | #3

> 
> On 9/8/21 11:34 PM, Avri Altman wrote:
> > +static bool ufs_temp_enabled(struct ufs_hba *hba, struct
> > +ufs_hwmon_data *data) {
> > +     u32 ee_mask;
> > +
> > +     if (ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_READ_ATTR,
> > +                           QUERY_ATTR_IDN_EE_CONTROL, 0, 0, &ee_mask))
> > +             return false;
> > +
> > +     return (data->mask & ee_mask & MASK_EE_TOO_HIGH_TEMP) ||
> > +             (data->mask & ee_mask & MASK_EE_TOO_LOW_TEMP); }
> 
> The above function uses data->mask but not data so it's probably better to
> pass
> data->mask directly as the second argument.
Done.

> 
> > +static bool ufs_temp_valid(struct ufs_hba *hba, struct ufs_hwmon_data
> *data,
> > +                        enum attr_idn idn, u32 value) {
> > +     return (idn == QUERY_ATTR_IDN_CASE_ROUGH_TEMP && value >= 1
> &&
> > +             value <= 250 && ufs_temp_enabled(hba, data)) ||
> > +           (idn == QUERY_ATTR_IDN_HIGH_TEMP_BOUND && value >= 100
> &&
> > +            value <= 250) ||
> > +           (idn == QUERY_ATTR_IDN_LOW_TEMP_BOUND && value >= 1 &&
> > +            value <= 80);
> > +}
> 
> Same comment for this function - if the above comment is addressed 'mask'
> can be passed as an argument instead of 'data'.
Done.
 
> > +static int ufs_get_temp(struct ufs_hba *hba, struct ufs_hwmon_data
> *data,
> > +                     enum attr_idn idn) {
> > +     u32 value;
> > +
> > +     if (ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_READ_ATTR, idn, 0,
> 0,
> > +         &value))
> > +             return 0;
> > +
> > +     if (ufs_temp_valid(hba, data, idn, value))
> > +             return value - 80;
> > +
> > +     return 0;
> > +}
> 
> Same comment here.
Done.
 
> > +void ufs_hwmon_remove(struct ufs_hba *hba) {
> > +     if (hba->hwmon_device) {
> > +             struct ufs_hwmon_data *data =
> > +                     dev_get_drvdata(hba->hwmon_device);
> > +
> > +             hwmon_device_unregister(hba->hwmon_device);
> > +             hba->hwmon_device = NULL;
> > +             kfree(data);
> > +     }
> > +}
> 
> Please use the "early return" style since that is the most widely used style in
> the Linux kernel (if (!hba->hwmon_device) return).
Done.


> 
> Thanks,
> 
> Bart.

Avri Altman Sept. 10, 2021, 4:13 p.m. UTC | #4

> > +     if (IS_ERR(hwmon)) {
> > +             dev_warn(dev, "Failed to instantiate hwmon device\n");
> > +             kfree(data);
> > +             return PTR_ERR(hwmon);
> 
> If the error is ignored by the caller, it doesn't make sense to return it.
Done.

> 
> > +     }
> > +
> > +     hba->hwmon_device = hwmon;
> > +
> > +     return 0;
> > +}
> > +
> > +void ufs_hwmon_remove(struct ufs_hba *hba) {
> > +     if (hba->hwmon_device) {
> > +             struct ufs_hwmon_data *data =
> > +                     dev_get_drvdata(hba->hwmon_device);
> > +
> > +             hwmon_device_unregister(hba->hwmon_device);
> > +             hba->hwmon_device = NULL;
> > +             kfree(data);
> > +     }
> > +}
> 
> That function is never called and thus pointless (suggesting that there may
> be some structural problem in the code).
Yayks... Forgot to call it from ufshcd_remve()
Thanks.

> >
> >       ufshcd_wb_probe(hba, desc_buf);
> >
> > +     ufshcd_temp_notif_probe(hba, desc_buf);
> > +
> 
> Is that the appropriate place to make this call ?
Yes I think so.
This path is on link startup when the host reads the device configuration.

> > +#ifdef CONFIG_SCSI_UFS_HWMON
> > +int ufs_hwmon_probe(struct ufs_hba *hba, u8 mask); void
> > +ufs_hwmon_remove(struct ufs_hba *hba); #else static inline int
> > +ufs_hwmon_probe(struct ufs_hba *hba, u8 mask) { return 0; } static
> > +inline void nvme_hwmon_remove(struct ufs_hba *hba) {}
> 
> ufs_hwmon_remove
Done. Thanks.

Patch

diff --git a/drivers/scsi/ufs/Kconfig b/drivers/scsi/ufs/Kconfig
index 432df76e6318..b930f29fc375 100644
--- a/drivers/scsi/ufs/Kconfig
+++ b/drivers/scsi/ufs/Kconfig
@@ -199,3 +199,13 @@  config SCSI_UFS_FAULT_INJECTION
 	help
 	  Enable fault injection support in the UFS driver. This makes it easier
 	  to test the UFS error handler and abort handler.
+
+config SCSI_UFS_HWMON
+	bool "UFS  Temperature Notification"
+	depends on SCSI_UFSHCD && HWMON
+	help
+	  This provides support for UFS hardware monitoring. If enabled,
+	  a hardware monitoring device will be created for the UFS device.
+
+	  If unsure, say N.
+
diff --git a/drivers/scsi/ufs/Makefile b/drivers/scsi/ufs/Makefile
index c407da9b5171..966048875b50 100644
--- a/drivers/scsi/ufs/Makefile
+++ b/drivers/scsi/ufs/Makefile
@@ -10,6 +10,7 @@  ufshcd-core-$(CONFIG_SCSI_UFS_BSG)	+= ufs_bsg.o
 ufshcd-core-$(CONFIG_SCSI_UFS_CRYPTO)	+= ufshcd-crypto.o
 ufshcd-core-$(CONFIG_SCSI_UFS_HPB)	+= ufshpb.o
 ufshcd-core-$(CONFIG_SCSI_UFS_FAULT_INJECTION) += ufs-fault-injection.o
+ufshcd-core-$(CONFIG_SCSI_UFS_HWMON) += ufs-hwmon.o
 
 obj-$(CONFIG_SCSI_UFS_DWC_TC_PCI) += tc-dwc-g210-pci.o ufshcd-dwc.o tc-dwc-g210.o
 obj-$(CONFIG_SCSI_UFS_DWC_TC_PLATFORM) += tc-dwc-g210-pltfrm.o ufshcd-dwc.o tc-dwc-g210.o
diff --git a/drivers/scsi/ufs/ufs-hwmon.c b/drivers/scsi/ufs/ufs-hwmon.c
new file mode 100644
index 000000000000..159678ce89ce
--- /dev/null
+++ b/drivers/scsi/ufs/ufs-hwmon.c
@@ -0,0 +1,180 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * UFS hardware monitoring support
+ * Copyright (c) 2021, Western Digital Corporation
+ */
+
+#include <linux/hwmon.h>
+
+#include "ufshcd.h"
+
+struct ufs_hwmon_data {
+	struct ufs_hba *hba;
+	u8 mask;
+};
+
+static bool ufs_temp_enabled(struct ufs_hba *hba, struct ufs_hwmon_data *data)
+{
+	u32 ee_mask;
+
+	if (ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_READ_ATTR,
+			      QUERY_ATTR_IDN_EE_CONTROL, 0, 0, &ee_mask))
+		return false;
+
+	return (data->mask & ee_mask & MASK_EE_TOO_HIGH_TEMP) ||
+		(data->mask & ee_mask & MASK_EE_TOO_LOW_TEMP);
+}
+
+static bool ufs_temp_valid(struct ufs_hba *hba, struct ufs_hwmon_data *data,
+			   enum attr_idn idn, u32 value)
+{
+	return (idn == QUERY_ATTR_IDN_CASE_ROUGH_TEMP && value >= 1 &&
+		value <= 250 && ufs_temp_enabled(hba, data)) ||
+	      (idn == QUERY_ATTR_IDN_HIGH_TEMP_BOUND && value >= 100 &&
+	       value <= 250) ||
+	      (idn == QUERY_ATTR_IDN_LOW_TEMP_BOUND && value >= 1 &&
+	       value <= 80);
+}
+
+static int ufs_get_temp(struct ufs_hba *hba, struct ufs_hwmon_data *data,
+			enum attr_idn idn)
+{
+	u32 value;
+
+	if (ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_READ_ATTR, idn, 0, 0,
+	    &value))
+		return 0;
+
+	if (ufs_temp_valid(hba, data, idn, value))
+		return value - 80;
+
+	return 0;
+}
+
+static int ufs_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
+			   u32 attr, int channel, long *val)
+{
+	struct ufs_hwmon_data *data = dev_get_drvdata(dev);
+	struct ufs_hba *hba = data->hba;
+	int err = 0;
+	bool get_temp = true;
+
+	if (type != hwmon_temp)
+		return 0;
+
+	down(&hba->host_sem);
+
+	if (!ufshcd_is_user_access_allowed(hba)) {
+		up(&hba->host_sem);
+		return -EBUSY;
+	}
+
+	ufshcd_rpm_get_sync(hba);
+
+	switch (attr) {
+	case hwmon_temp_enable:
+		*val = ufs_temp_enabled(hba, data);
+		get_temp = false;
+
+		break;
+	case hwmon_temp_max_alarm:
+		*val = ufs_get_temp(hba, data, QUERY_ATTR_IDN_HIGH_TEMP_BOUND);
+
+		break;
+	case hwmon_temp_min_alarm:
+		*val = ufs_get_temp(hba, data, QUERY_ATTR_IDN_LOW_TEMP_BOUND);
+
+		break;
+	case hwmon_temp_input:
+		*val = ufs_get_temp(hba, data, QUERY_ATTR_IDN_CASE_ROUGH_TEMP);
+
+		break;
+	default:
+		err = -EOPNOTSUPP;
+
+		break;
+	}
+
+	ufshcd_rpm_put_sync(hba);
+
+	up(&hba->host_sem);
+
+	if (get_temp && !err && *val == 0)
+		err = -EINVAL;
+
+	return err;
+}
+
+static umode_t ufs_hwmon_is_visible(const void *_data,
+				     enum hwmon_sensor_types type,
+				     u32 attr, int channel)
+{
+	if (type != hwmon_temp)
+		return 0;
+
+	switch (attr) {
+	case hwmon_temp_enable:
+	case hwmon_temp_max_alarm:
+	case hwmon_temp_min_alarm:
+	case hwmon_temp_input:
+		return 0444;
+	default:
+		break;
+	}
+	return 0;
+}
+
+static const struct hwmon_channel_info *ufs_hwmon_info[] = {
+	HWMON_CHANNEL_INFO(temp, HWMON_T_ENABLE | HWMON_T_INPUT |
+			    HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM),
+	NULL
+};
+
+static const struct hwmon_ops ufs_hwmon_ops = {
+	.is_visible	= ufs_hwmon_is_visible,
+	.read		= ufs_hwmon_read,
+};
+
+static const struct hwmon_chip_info ufs_hwmon_hba_info = {
+	.ops	= &ufs_hwmon_ops,
+	.info	= ufs_hwmon_info,
+};
+
+int ufs_hwmon_probe(struct ufs_hba *hba, u8 mask)
+{
+	struct device *dev = hba->dev;
+	struct ufs_hwmon_data *data;
+	struct device *hwmon;
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return 0;
+
+	data->hba = hba;
+	data->mask = mask;
+
+	hwmon = hwmon_device_register_with_info(dev, "ufs",
+						data, &ufs_hwmon_hba_info,
+						NULL);
+	if (IS_ERR(hwmon)) {
+		dev_warn(dev, "Failed to instantiate hwmon device\n");
+		kfree(data);
+		return PTR_ERR(hwmon);
+	}
+
+	hba->hwmon_device = hwmon;
+
+	return 0;
+}
+
+void ufs_hwmon_remove(struct ufs_hba *hba)
+{
+	if (hba->hwmon_device) {
+		struct ufs_hwmon_data *data =
+			dev_get_drvdata(hba->hwmon_device);
+
+		hwmon_device_unregister(hba->hwmon_device);
+		hba->hwmon_device = NULL;
+		kfree(data);
+	}
+}
diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h
index 8c6b38b1b142..171b27be7b1d 100644
--- a/drivers/scsi/ufs/ufs.h
+++ b/drivers/scsi/ufs/ufs.h
@@ -152,6 +152,9 @@  enum attr_idn {
 	QUERY_ATTR_IDN_PSA_STATE		= 0x15,
 	QUERY_ATTR_IDN_PSA_DATA_SIZE		= 0x16,
 	QUERY_ATTR_IDN_REF_CLK_GATING_WAIT_TIME	= 0x17,
+	QUERY_ATTR_IDN_CASE_ROUGH_TEMP          = 0x18,
+	QUERY_ATTR_IDN_HIGH_TEMP_BOUND          = 0x19,
+	QUERY_ATTR_IDN_LOW_TEMP_BOUND           = 0x1A,
 	QUERY_ATTR_IDN_WB_FLUSH_STATUS	        = 0x1C,
 	QUERY_ATTR_IDN_AVAIL_WB_BUFF_SIZE       = 0x1D,
 	QUERY_ATTR_IDN_WB_BUFF_LIFE_TIME_EST    = 0x1E,
@@ -338,6 +341,9 @@  enum {
 
 /* Possible values for dExtendedUFSFeaturesSupport */
 enum {
+	UFS_DEV_LOW_TEMP_NOTIF		= BIT(4),
+	UFS_DEV_HIGH_TEMP_NOTIF		= BIT(5),
+	UFS_DEV_EXT_TEMP_NOTIF		= BIT(6),
 	UFS_DEV_HPB_SUPPORT		= BIT(7),
 	UFS_DEV_WRITE_BOOSTER_SUP	= BIT(8),
 };
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 3841ab49f556..fc995bf1f296 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -7469,6 +7469,31 @@  static void ufshcd_wb_probe(struct ufs_hba *hba, u8 *desc_buf)
 	hba->caps &= ~UFSHCD_CAP_WB_EN;
 }
 
+static void ufshcd_temp_notif_probe(struct ufs_hba *hba, u8 *desc_buf)
+{
+	struct ufs_dev_info *dev_info = &hba->dev_info;
+	u32 ext_ufs_feature;
+	u8 mask = 0;
+
+	if (!(hba->caps & UFSHCD_CAP_TEMP_NOTIF) ||
+	    dev_info->wspecversion < 0x300)
+		return;
+
+	ext_ufs_feature = get_unaligned_be32(desc_buf +
+					DEVICE_DESC_PARAM_EXT_UFS_FEATURE_SUP);
+
+	if (ext_ufs_feature & UFS_DEV_LOW_TEMP_NOTIF)
+		mask |= MASK_EE_TOO_LOW_TEMP;
+
+	if (ext_ufs_feature & UFS_DEV_HIGH_TEMP_NOTIF)
+		mask |= MASK_EE_TOO_HIGH_TEMP;
+
+	if (mask) {
+		ufshcd_enable_ee(hba, mask);
+		ufs_hwmon_probe(hba, mask);
+	}
+}
+
 void ufshcd_fixup_dev_quirks(struct ufs_hba *hba, struct ufs_dev_fix *fixups)
 {
 	struct ufs_dev_fix *f;
@@ -7564,6 +7589,8 @@  static int ufs_get_device_desc(struct ufs_hba *hba)
 
 	ufshcd_wb_probe(hba, desc_buf);
 
+	ufshcd_temp_notif_probe(hba, desc_buf);
+
 	/*
 	 * ufshcd_read_string_desc returns size of the string
 	 * reset the error value
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 52ea6f350b18..9bc434c4ae71 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -653,6 +653,12 @@  enum ufshcd_caps {
 	 * in order to exit DeepSleep state.
 	 */
 	UFSHCD_CAP_DEEPSLEEP				= 1 << 10,
+
+	/*
+	 * This capability allows the host controller driver to use temperature
+	 * notification if it is supported by the UFS device.
+	 */
+	UFSHCD_CAP_TEMP_NOTIF				= 1 << 11,
 };
 
 struct ufs_hba_variant_params {
@@ -789,6 +795,10 @@  struct ufs_hba {
 	struct scsi_device *sdev_ufs_device;
 	struct scsi_device *sdev_rpmb;
 
+#ifdef CONFIG_SCSI_UFS_HWMON
+	struct device *hwmon_device;
+#endif
+
 	enum ufs_dev_pwr_mode curr_dev_pwr_mode;
 	enum uic_link_state uic_link_state;
 	/* Desired UFS power management level during runtime PM */
@@ -1049,6 +1059,14 @@  static inline u8 ufshcd_wb_get_query_index(struct ufs_hba *hba)
 	return 0;
 }
 
+#ifdef CONFIG_SCSI_UFS_HWMON
+int ufs_hwmon_probe(struct ufs_hba *hba, u8 mask);
+void ufs_hwmon_remove(struct ufs_hba *hba);
+#else
+static inline int ufs_hwmon_probe(struct ufs_hba *hba, u8 mask) { return 0; }
+static inline void nvme_hwmon_remove(struct ufs_hba *hba) {}
+#endif
+
 #ifdef CONFIG_PM
 extern int ufshcd_runtime_suspend(struct device *dev);
 extern int ufshcd_runtime_resume(struct device *dev);