Re: [RESEND PATCH 1/5] scsi: ufs: Add ufs thermal support

[Daniel Lezcano <daniel.lezcano@linaro.org>]

On 23/02/2020 10:35, Avi Shchislowski wrote:
> From: Avi Shchislowski <avi.shchislowski@sandisk.com>
> 
> Support the new temperature notification attributes introduced in
> UFSv3.0. Add exception event mask, and ufs features attributes.
> 
> Signed-off-by: Avi Shchislowski <avi.shchislowski@sandisk.com>
> ---
>  drivers/scsi/ufs/Kconfig       |  11 ++++
>  drivers/scsi/ufs/Makefile      |   1 +
>  drivers/scsi/ufs/ufs-thermal.c | 123 +++++++++++++++++++++++++++++++++++++++++

Why not put the driver under drivers/thermal/ ?

>  drivers/scsi/ufs/ufs-thermal.h |  19 +++++++
>  drivers/scsi/ufs/ufs.h         |  11 ++++
>  drivers/scsi/ufs/ufshcd.c      |   3 +
>  drivers/scsi/ufs/ufshcd.h      |  10 ++++
>  7 files changed, 178 insertions(+)
>  create mode 100644 drivers/scsi/ufs/ufs-thermal.c
>  create mode 100644 drivers/scsi/ufs/ufs-thermal.h
> 
> diff --git a/drivers/scsi/ufs/Kconfig b/drivers/scsi/ufs/Kconfig
> index d14c224..bed56ee 100644
> --- a/drivers/scsi/ufs/Kconfig
> +++ b/drivers/scsi/ufs/Kconfig
> @@ -160,3 +160,14 @@ config SCSI_UFS_BSG
>  
>  	  Select this if you need a bsg device node for your UFS controller.
>  	  If unsure, say N.
> +
> +config THERMAL_UFS
> +	bool "Thermal UFS"
> +	depends on THERMAL && SCSI_UFSHCD
> +	help
> +	  A UFS3.0 feature that allows using the ufs device as a temperature
> +	  sensor. it provide notification to the host when the UFS device
> +	  case temperature approaches its pre-defined boundaries.
> +
> +	  Select Y to enable this feature, otherwise say N.
> +	  If unsure, say N.
> \ No newline at end of file

  ^^^^

> diff --git a/drivers/scsi/ufs/Makefile b/drivers/scsi/ufs/Makefile
> index 94c6c5d..fd35941 100644
> --- a/drivers/scsi/ufs/Makefile
> +++ b/drivers/scsi/ufs/Makefile
> @@ -12,3 +12,4 @@ obj-$(CONFIG_SCSI_UFSHCD_PLATFORM) += ufshcd-pltfrm.o
>  obj-$(CONFIG_SCSI_UFS_HISI) += ufs-hisi.o
>  obj-$(CONFIG_SCSI_UFS_MEDIATEK) += ufs-mediatek.o
>  obj-$(CONFIG_SCSI_UFS_TI_J721E) += ti-j721e-ufs.o
> +obj-$(CONFIG_THERMAL_UFS) += ufs-thermal.o
> diff --git a/drivers/scsi/ufs/ufs-thermal.c b/drivers/scsi/ufs/ufs-thermal.c
> new file mode 100644
> index 0000000..469c1ed
> --- /dev/null
> +++ b/drivers/scsi/ufs/ufs-thermal.c
> @@ -0,0 +1,123 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * thermal ufs
> + *
> + * Copyright (C) 2020 Western Digital Corporation
> + */
> +#include <linux/thermal.h>
> +#include "ufs-thermal.h"
> +
> +enum {
> +	UFS_THERM_MAX_TEMP,
> +	UFS_THERM_HIGH_TEMP,
> +	UFS_THERM_LOW_TEMP,
> +	UFS_THERM_MIN_TEMP,
> +
> +	/* keep last */
> +	UFS_THERM_MAX_TRIPS
> +};
> +
> +/**
> + *struct ufs_thermal - thermal zone related data
> + * @tzone: thermal zone device data
> + */
> +static struct ufs_thermal {
> +	struct thermal_zone_device *zone;
> +} thermal;
> +
> +static  struct thermal_zone_device_ops ufs_thermal_ops = {
> +	.get_temp = NULL,
> +	.get_trip_temp = NULL,
> +	.get_trip_type = NULL,
> +};

Can you merge all the patches related to this driver into a single one?

> +static int ufs_thermal_enable_ee(struct ufs_hba *hba)
> +{
> +	/* later */
> +	return -EINVAL;
> +}
> +
> +static void ufs_thermal_zone_unregister(struct ufs_hba *hba)
> +{
> +	if (thermal.zone) {
> +		dev_dbg(hba->dev, "Thermal zone device unregister\n");
> +		thermal_zone_device_unregister(thermal.zone);
> +		thermal.zone = NULL;
> +	}
> +}
> +
> +static int ufs_thermal_register(struct ufs_hba *hba)
> +{
> +	int err = 0;
> +	char name[THERMAL_NAME_LENGTH] = {};
> +
> +	snprintf(name, THERMAL_NAME_LENGTH, "ufs_storage_%d",
> +			hba->host->host_no);
> +
> +	thermal.zone = thermal_zone_device_register(name, UFS_THERM_MAX_TRIPS,
> +			0, hba, &ufs_thermal_ops, NULL, 0, 0);
> +	if (IS_ERR(thermal.zone)) {
> +		err = PTR_ERR(thermal.zone);
> +		dev_err(hba->dev, "Failed to register to thermal zone, err %d\n",
> +				err);
> +		thermal.zone = NULL;
> +		goto out;
> +	}

It is pointless to reassign thermal.zone to NULL.

As there is no rollback involved here, This can be simplified to:

if (IS_ERR(thermal.zone)) {
	dev_err(hba->dev, "...");
	return PTR_ERR(thermal.zone);
}

> +
> +	 /* thermal support is enabled only after successful

nit: comment format

/*
 * thermal support ...
 * ...
 */

> +	  * enablement of thermal exception
> +	  */
> +	if (ufs_thermal_enable_ee(hba)) {
> +		dev_info(hba->dev, "Failed to enable thermal exception\n");
> +		ufs_thermal_zone_unregister(hba);
> +		err = -EINVAL;
> +	}

	err = ufs_thermal_enable_ee(hba);
	if (err) {
		...
		return err;
	}

	return 0;

> +
> +out:
> +	return err;
> +}
> +
> +int ufs_thermal_probe(struct ufs_hba *hba)
> +{
> +	u8 ufs_features;
> +	u8 *desc_buf = NULL;
> +	int err = -EINVAL;
> +
> +	if (!ufshcd_thermal_management_enabled(hba))
> +		goto out;
> +
> +	desc_buf = kzalloc(hba->desc_size.dev_desc, GFP_KERNEL);
> +	if (!desc_buf) {
> +		err = -ENOMEM;
> +		goto out;
> +	}
> +
> +	if (ufshcd_read_desc_param(hba, QUERY_DESC_IDN_DEVICE, 0, 0, desc_buf,
> +			hba->desc_size.dev_desc))
> +		goto out;
> +
> +
> +	ufs_features = desc_buf[DEVICE_DESC_PARAM_UFS_FEAT] &
> +			(UFS_FEATURE_HTEMP | UFS_FEATURE_LTEMP);
> +	if (!ufs_features)
> +		goto out;
> +
> +	err = ufs_thermal_register(hba);
> +	if (err)
> +		goto out;
> +
> +	hba->thermal_features = ufs_features;
> +
> +out:
> +	kfree(desc_buf);
> +	return err;
> +}
> +
> +void ufs_thermal_remove(struct ufs_hba *hba)
> +{
> +	if (!ufshcd_thermal_management_enabled(hba))
> +		return;
> +
> +	 ufs_thermal_zone_unregister(hba);
> +	 hba->thermal_features = 0;

Why is this needed ?

> +}
> diff --git a/drivers/scsi/ufs/ufs-thermal.h b/drivers/scsi/ufs/ufs-thermal.h
> new file mode 100644
> index 0000000..7c0fcbe
> --- /dev/null
> +++ b/drivers/scsi/ufs/ufs-thermal.h
> @@ -0,0 +1,19 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2018 Western Digital Corporation
> + */
> +#ifndef UFS_THERMAL_H
> +#define UFS_THERMAL_H
> +
> +#include "ufshcd.h"
> +#include "ufs.h"
> +
> +#ifdef CONFIG_THERMAL_UFS
> +void ufs_thermal_remove(struct ufs_hba *hba);
> +int ufs_thermal_probe(struct ufs_hba *hba);
> +#else
> +static inline void ufs_thermal_remove(struct ufs_hba *hba) {}
> +static inline int ufs_thermal_probe(struct ufs_hba *hba) {return 0; }
> +#endif /* CONFIG_THERMAL_UFS */
> +
> +#endif /* UFS_THERMAL_H */
> diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h
> index dde2eb0..eb729cc 100644
> --- a/drivers/scsi/ufs/ufs.h
> +++ b/drivers/scsi/ufs/ufs.h
> @@ -332,6 +332,17 @@ enum {
>  	UFSHCD_AMP		= 3,
>  };
>  
> +/* UFS Features - to decode bUFSFeaturesSupport */
> +enum {
> +	UFS_FEATURE_FFU		= BIT(0),
> +	UFS_FEATURE_PSA		= BIT(1),
> +	UFS_FEATURE_LIFE		= BIT(2),
> +	UFS_FEATURE_REFRESH		= BIT(3),
> +	UFS_FEATURE_HTEMP		= BIT(4),
> +	UFS_FEATURE_LTEMP		= BIT(5),
> +	UFS_FEATURE_ETEMP		= BIT(6),
> +};
> +
>  #define POWER_DESC_MAX_SIZE			0x62
>  #define POWER_DESC_MAX_ACTV_ICC_LVLS		16
>  
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index abd0e6b..099d2de 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -47,6 +47,7 @@
>  #include "unipro.h"
>  #include "ufs-sysfs.h"
>  #include "ufs_bsg.h"
> +#include "ufs-thermal.h"
>  
>  #define CREATE_TRACE_POINTS
>  #include <trace/events/ufs.h>
> @@ -7111,6 +7112,7 @@ static int ufshcd_probe_hba(struct ufs_hba *hba, bool async)
>  
>  	/* Enable Auto-Hibernate if configured */
>  	ufshcd_auto_hibern8_enable(hba);
> +	ufs_thermal_probe(hba);
>  
>  out:
>  
> @@ -8278,6 +8280,7 @@ int ufshcd_shutdown(struct ufs_hba *hba)
>   */
>  void ufshcd_remove(struct ufs_hba *hba)
>  {
> +	ufs_thermal_remove(hba);
>  	ufs_bsg_remove(hba);
>  	ufs_sysfs_remove_nodes(hba->dev);
>  	blk_cleanup_queue(hba->tmf_queue);
> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> index 2ae6c7c..28c0063 100644
> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@ -730,6 +730,11 @@ struct ufs_hba {
>  
>  	struct device		bsg_dev;
>  	struct request_queue	*bsg_queue;
> +
> +#define UFSHCD_CAP_THERMAL_MANAGEMENT (1 << 7)
> +
> +	u8 thermal_features;
> +
>  };
>  
>  /* Returns true if clocks can be gated. Otherwise false */
> @@ -754,6 +759,11 @@ static inline bool ufshcd_is_rpm_autosuspend_allowed(struct ufs_hba *hba)
>  	return hba->caps & UFSHCD_CAP_RPM_AUTOSUSPEND;
>  }
>  
> +static inline bool ufshcd_thermal_management_enabled(struct ufs_hba *hba)
> +{
> +	return hba->caps & UFSHCD_CAP_THERMAL_MANAGEMENT;
> +}
> +
>  static inline bool ufshcd_is_intr_aggr_allowed(struct ufs_hba *hba)
>  {
>  /* DWC UFS Core has the Interrupt aggregation feature but is not detectable*/
> 


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