Unverified Commit 92c025db authored by Suma Hegde's avatar Suma Hegde Committed by Ilpo Järvinen
Browse files

platform/x86/amd/hsmp: Report power via hwmon sensors 



Expose power reading and power limits via hwmon power sensors.

Signed-off-by: default avatarSuma Hegde <suma.hegde@amd.com>
Reviewed-by: default avatarNaveen Krishna Chatradhi <naveenkrishna.chatradhi@amd.com>
Link: https://lore.kernel.org/r/20250506101542.200811-2-suma.hegde@amd.com


Reviewed-by: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
parent cf8dea42

Documentation/arch/x86/amd_hsmp.rst

+8 −0
Original line number Diff line number Diff line
@@ -116,6 +116,14 @@ for socket with ID00 is given below:: 
			})

		}



HSMP HWMON interface

====================

HSMP power sensors are registered with the hwmon interface. A separate hwmon

directory is created for each socket and the following files are generated

within the hwmon directory.

- power1_input (read only)

- power1_cap_max (read only)

- power1_cap (read, write)



An example

==========

drivers/platform/x86/amd/hsmp/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -6,6 +6,7 @@ 


obj-$(CONFIG_AMD_HSMP)			+= hsmp_common.o

hsmp_common-y				:= hsmp.o

hsmp_common-$(CONFIG_HWMON)		+= hwmon.o

obj-$(CONFIG_AMD_HSMP_PLAT)		+= amd_hsmp.o

amd_hsmp-y				:= plat.o

obj-$(CONFIG_AMD_HSMP_ACPI)		+= hsmp_acpi.o

drivers/platform/x86/amd/hsmp/acpi.c

+4 −0
Original line number Diff line number Diff line
@@ -281,6 +281,10 @@ static int init_acpi(struct device *dev) 
			dev_err(dev, "Failed to init metric table\n");

	}



	ret = hsmp_create_sensor(dev, sock_ind);

	if (ret)

		dev_err(dev, "Failed to register HSMP sensors with hwmon\n");



	return ret;

}

drivers/platform/x86/amd/hsmp/hsmp.h

+7 −1
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@@ -12,6 +12,7 @@ 


#include <linux/compiler_types.h>

#include <linux/device.h>

#include <linux/hwmon.h>

#include <linux/miscdevice.h>

#include <linux/pci.h>

#include <linux/semaphore.h>
@@ -25,7 +26,7 @@ 
#define HSMP_DEVNODE_NAME	"hsmp"

#define ACPI_HSMP_DEVICE_HID    "AMDI0097"



#define DRIVER_VERSION		"2.4"

#define DRIVER_VERSION		"2.5"



struct hsmp_mbaddr_info {

	u32 base_addr;
@@ -63,4 +64,9 @@ int hsmp_misc_register(struct device *dev); 
int hsmp_get_tbl_dram_base(u16 sock_ind);

ssize_t hsmp_metric_tbl_read(struct hsmp_socket *sock, char *buf, size_t size);

struct hsmp_plat_device *get_hsmp_pdev(void);

#if IS_REACHABLE(CONFIG_HWMON)

int hsmp_create_sensor(struct device *dev, u16 sock_ind);

#else

static inline int hsmp_create_sensor(struct device *dev, u16 sock_ind) { return 0; }

#endif

#endif /* HSMP_H */

drivers/platform/x86/amd/hsmp/hwmon.c

0 → 100644
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// SPDX-License-Identifier: GPL-2.0

/*

 * AMD HSMP hwmon support

 * Copyright (c) 2025, AMD.

 * All Rights Reserved.

 *

 * This file provides hwmon implementation for HSMP interface.

 */



#include <asm/amd_hsmp.h>



#include <linux/device.h>

#include <linux/err.h>

#include <linux/hwmon.h>

#include <linux/types.h>

#include <linux/units.h>



#include "hsmp.h"



#define HSMP_HWMON_NAME		"amd_hsmp_hwmon"



static int hsmp_hwmon_write(struct device *dev, enum hwmon_sensor_types type,

			    u32 attr, int channel, long val)

{

	u16 sock_ind = (uintptr_t)dev_get_drvdata(dev);

	struct hsmp_message msg = {};



	if (type != hwmon_power)

		return -EOPNOTSUPP;



	if (attr != hwmon_power_cap)

		return -EOPNOTSUPP;



	msg.num_args = 1;

	msg.args[0] = val / MICROWATT_PER_MILLIWATT;

	msg.msg_id = HSMP_SET_SOCKET_POWER_LIMIT;

	msg.sock_ind = sock_ind;

	return hsmp_send_message(&msg);

}



static int hsmp_hwmon_read(struct device *dev,

			   enum hwmon_sensor_types type,

			   u32 attr, int channel, long *val)

{

	u16 sock_ind = (uintptr_t)dev_get_drvdata(dev);

	struct hsmp_message msg = {};

	int ret;



	if (type != hwmon_power)

		return -EOPNOTSUPP;



	msg.sock_ind = sock_ind;

	msg.response_sz = 1;



	switch (attr) {

	case hwmon_power_input:

		msg.msg_id = HSMP_GET_SOCKET_POWER;

		break;

	case hwmon_power_cap:

		msg.msg_id = HSMP_GET_SOCKET_POWER_LIMIT;

		break;

	case hwmon_power_cap_max:

		msg.msg_id = HSMP_GET_SOCKET_POWER_LIMIT_MAX;

		break;

	default:

		return -EOPNOTSUPP;

	}



	ret = hsmp_send_message(&msg);

	if (!ret)

		*val = msg.args[0] * MICROWATT_PER_MILLIWATT;



	return ret;

}



static umode_t hsmp_hwmon_is_visble(const void *data,

				    enum hwmon_sensor_types type,

				    u32 attr, int channel)

{

	if (type != hwmon_power)

		return 0;



	switch (attr) {

	case hwmon_power_input:

		return 0444;

	case hwmon_power_cap:

		return 0644;

	case hwmon_power_cap_max:

		return 0444;

	default:

		return 0;

	}

}



static const struct hwmon_ops hsmp_hwmon_ops = {

	.read = hsmp_hwmon_read,

	.is_visible = hsmp_hwmon_is_visble,

	.write	= hsmp_hwmon_write,

};



static const struct hwmon_channel_info * const hsmp_info[] = {

	HWMON_CHANNEL_INFO(power, HWMON_P_INPUT | HWMON_P_CAP | HWMON_P_CAP_MAX),

	NULL

};



static const struct hwmon_chip_info hsmp_chip_info = {

	.ops = &hsmp_hwmon_ops,

	.info = hsmp_info,

};



int hsmp_create_sensor(struct device *dev, u16 sock_ind)

{

	struct device *hwmon_dev;



	hwmon_dev = devm_hwmon_device_register_with_info(dev, HSMP_HWMON_NAME,

							 (void *)(uintptr_t)sock_ind,

							 &hsmp_chip_info,

							 NULL);

	return PTR_ERR_OR_ZERO(hwmon_dev);

}

EXPORT_SYMBOL_NS(hsmp_create_sensor, "AMD_HSMP");