hwmon: (asus-ec-sensors) implement locking via the ACPI global lock (de8fbac5) · Commits · EulixOS / Software / Kernel

Documentation/hwmon/asus_ec_sensors.rst

+2 −0

Original line number	Diff line number	Diff line
		@@ -53,3 +53,5 @@ Module Parameters
		the path is mostly identical for them). If ASUS changes this path
		in a future BIOS update, this parameter can be used to override
		the stored in the driver value until it gets updated.
		A special string ":GLOBAL_LOCK" can be passed to use the ACPI
		global lock instead of a dedicated mutex.

drivers/hwmon/asus-ec-sensors.c

+99 −26

Original line number	Diff line number	Diff line
		@@ -56,6 +56,9 @@ static char *mutex_path_override;

		#define MAX_IDENTICAL_BOARD_VARIATIONS 2

		/* Moniker for the ACPI global lock (':' is not allowed in ASL identifiers) */
		#define ACPI_GLOBAL_LOCK_PSEUDO_PATH ":GLOBAL_LOCK"

		typedef union {
		u32 value;
		struct {
		@@ -166,6 +169,14 @@ static const struct ec_sensor_info known_ec_sensors[] = {
		struct ec_board_info {
		const char *board_names[MAX_IDENTICAL_BOARD_VARIATIONS];
		unsigned long sensors;
		/*
		* Defines which mutex to use for guarding access to the state and the
		* hardware. Can be either a full path to an AML mutex or the
		* pseudo-path ACPI_GLOBAL_LOCK_PSEUDO_PATH to use the global ACPI lock,
		* or left empty to use a regular mutex object, in which case access to
		* the hardware is not guarded.
		*/
		const char *mutex_path;
		};

		static const struct ec_board_info board_info[] = {
		@@ -173,6 +184,7 @@ static const struct ec_board_info board_info[] = {
		.board_names = {"PRIME X570-PRO"},
		.sensors = SENSOR_SET_TEMP_CHIPSET_CPU_MB \| SENSOR_TEMP_VRM \|
		SENSOR_TEMP_T_SENSOR \| SENSOR_FAN_CHIPSET,
		.mutex_path = ASUS_HW_ACCESS_MUTEX_ASMX,
		},
		{
		.board_names = {"ProArt X570-CREATOR WIFI"},
		@@ -185,6 +197,7 @@ static const struct ec_board_info board_info[] = {
		.sensors = SENSOR_SET_TEMP_CHIPSET_CPU_MB \| SENSOR_TEMP_VRM \|
		SENSOR_TEMP_T_SENSOR \| SENSOR_FAN_CHIPSET \|
		SENSOR_CURR_CPU \| SENSOR_IN_CPU_CORE,
		.mutex_path = ASUS_HW_ACCESS_MUTEX_ASMX,
		},
		{
		.board_names = {"ROG CROSSHAIR VIII DARK HERO"},
		@@ -193,6 +206,7 @@ static const struct ec_board_info board_info[] = {
		SENSOR_TEMP_VRM \| SENSOR_SET_TEMP_WATER \|
		SENSOR_FAN_CPU_OPT \| SENSOR_FAN_WATER_FLOW \|
		SENSOR_CURR_CPU \| SENSOR_IN_CPU_CORE,
		.mutex_path = ASUS_HW_ACCESS_MUTEX_ASMX,
		},
		{
		.board_names = {"ROG CROSSHAIR VIII FORMULA"},
		@@ -200,6 +214,7 @@ static const struct ec_board_info board_info[] = {
		SENSOR_TEMP_T_SENSOR \| SENSOR_TEMP_VRM \|
		SENSOR_FAN_CPU_OPT \| SENSOR_FAN_CHIPSET \|
		SENSOR_CURR_CPU \| SENSOR_IN_CPU_CORE,
		.mutex_path = ASUS_HW_ACCESS_MUTEX_ASMX,
		},
		{
		.board_names = {
		@@ -212,6 +227,7 @@ static const struct ec_board_info board_info[] = {
		SENSOR_FAN_CPU_OPT \| SENSOR_FAN_CHIPSET \|
		SENSOR_FAN_WATER_FLOW \| SENSOR_CURR_CPU \|
		SENSOR_IN_CPU_CORE,
		.mutex_path = ASUS_HW_ACCESS_MUTEX_ASMX,
		},
		{
		.board_names = {"ROG CROSSHAIR VIII IMPACT"},
		@@ -219,12 +235,14 @@ static const struct ec_board_info board_info[] = {
		SENSOR_TEMP_T_SENSOR \| SENSOR_TEMP_VRM \|
		SENSOR_FAN_CHIPSET \| SENSOR_CURR_CPU \|
		SENSOR_IN_CPU_CORE,
		.mutex_path = ASUS_HW_ACCESS_MUTEX_ASMX,
		},
		{
		.board_names = {"ROG STRIX B550-E GAMING"},
		.sensors = SENSOR_SET_TEMP_CHIPSET_CPU_MB \|
		SENSOR_TEMP_T_SENSOR \| SENSOR_TEMP_VRM \|
		SENSOR_FAN_CPU_OPT,
		.mutex_path = ASUS_HW_ACCESS_MUTEX_ASMX,
		},
		{
		.board_names = {"ROG STRIX B550-I GAMING"},
		@@ -232,6 +250,7 @@ static const struct ec_board_info board_info[] = {
		SENSOR_TEMP_T_SENSOR \| SENSOR_TEMP_VRM \|
		SENSOR_FAN_VRM_HS \| SENSOR_CURR_CPU \|
		SENSOR_IN_CPU_CORE,
		.mutex_path = ASUS_HW_ACCESS_MUTEX_ASMX,
		},
		{
		.board_names = {"ROG STRIX X570-E GAMING"},
		@@ -239,17 +258,20 @@ static const struct ec_board_info board_info[] = {
		SENSOR_TEMP_T_SENSOR \| SENSOR_TEMP_VRM \|
		SENSOR_FAN_CHIPSET \| SENSOR_CURR_CPU \|
		SENSOR_IN_CPU_CORE,
		.mutex_path = ASUS_HW_ACCESS_MUTEX_ASMX,
		},
		{
		.board_names = {"ROG STRIX X570-F GAMING"},
		.sensors = SENSOR_SET_TEMP_CHIPSET_CPU_MB \|
		SENSOR_TEMP_T_SENSOR \| SENSOR_FAN_CHIPSET,
		.mutex_path = ASUS_HW_ACCESS_MUTEX_ASMX,
		},
		{
		.board_names = {"ROG STRIX X570-I GAMING"},
		.sensors = SENSOR_TEMP_T_SENSOR \| SENSOR_FAN_VRM_HS \|
		SENSOR_FAN_CHIPSET \| SENSOR_CURR_CPU \|
		SENSOR_IN_CPU_CORE,
		.mutex_path = ASUS_HW_ACCESS_MUTEX_ASMX,
		},
		{}
		};
		@@ -259,6 +281,46 @@ struct ec_sensor {
		s32 cached_value;
		};

		struct lock_data {
		union {
		acpi_handle aml;
		/* global lock handle */
		u32 glk;
		} mutex;
		bool (lock)(struct lock_data data);
		bool (unlock)(struct lock_data data);
		};

		/*
		* The next function pairs implement options for locking access to the
		* state and the EC
		*/
		static bool lock_via_acpi_mutex(struct lock_data *data)
		{
		/*
		* ASUS DSDT does not specify that access to the EC has to be guarded,
		* but firmware does access it via ACPI
		*/
		return ACPI_SUCCESS(acpi_acquire_mutex(data->mutex.aml,
		NULL, ACPI_LOCK_DELAY_MS));
		}

		static bool unlock_acpi_mutex(struct lock_data *data)
		{
		return ACPI_SUCCESS(acpi_release_mutex(data->mutex.aml, NULL));
		}

		static bool lock_via_global_acpi_lock(struct lock_data *data)
		{
		return ACPI_SUCCESS(acpi_acquire_global_lock(ACPI_LOCK_DELAY_MS,
		&data->mutex.glk));
		}

		static bool unlock_global_acpi_lock(struct lock_data *data)
		{
		return ACPI_SUCCESS(acpi_release_global_lock(data->mutex.glk));
		}

		struct ec_sensors_data {
		const struct ec_board_info *board_info;
		struct ec_sensor *sensors;
		@@ -269,7 +331,7 @@ struct ec_sensors_data {
		u8 banks[ASUS_EC_MAX_BANK + 1];
		/* in jiffies */
		unsigned long last_updated;
		acpi_handle aml_mutex;
		struct lock_data lock_data;
		/* number of board EC sensors */
		u8 nr_sensors;
		/*
		@@ -373,23 +435,36 @@ static void __init fill_ec_registers(struct ec_sensors_data *ec)
		}
		}

		static acpi_handle __init asus_hw_access_mutex(struct device *dev)
		static int __init setup_lock_data(struct device *dev)
		{
		const char *mutex_path;
		acpi_handle res;
		int status;
		struct ec_sensors_data *state = dev_get_drvdata(dev);

		mutex_path = mutex_path_override ?
		mutex_path_override : ASUS_HW_ACCESS_MUTEX_ASMX;
		mutex_path_override : state->board_info->mutex_path;

		status = acpi_get_handle(NULL, (acpi_string)mutex_path, &res);
		if (!mutex_path \|\| !strlen(mutex_path)) {
		dev_err(dev, "Hardware access guard mutex name is empty");
		return -EINVAL;
		}
		if (!strcmp(mutex_path, ACPI_GLOBAL_LOCK_PSEUDO_PATH)) {
		state->lock_data.mutex.glk = 0;
		state->lock_data.lock = lock_via_global_acpi_lock;
		state->lock_data.unlock = unlock_global_acpi_lock;
		} else {
		status = acpi_get_handle(NULL, (acpi_string)mutex_path,
		&state->lock_data.mutex.aml);
		if (ACPI_FAILURE(status)) {
		dev_err(dev,
		"Could not get hardware access guard mutex '%s': error %d",
		"Failed to get hardware access guard AML mutex '%s': error %d",
		mutex_path, status);
		return NULL;
		return -ENOENT;
		}
		state->lock_data.lock = lock_via_acpi_mutex;
		state->lock_data.unlock = unlock_acpi_mutex;
		}
		return res;
		return 0;
		}

		static int asus_ec_bank_switch(u8 bank, u8 *old)
		@@ -492,15 +567,9 @@ static int update_ec_sensors(const struct device *dev,
		{
		int status;

		/*
		* ASUS DSDT does not specify that access to the EC has to be guarded,
		* but firmware does access it via ACPI
		*/
		if (ACPI_FAILURE(acpi_acquire_mutex(ec->aml_mutex, NULL,
		ACPI_LOCK_DELAY_MS))) {
		dev_err(dev, "Failed to acquire AML mutex");
		status = -EBUSY;
		goto cleanup;
		if (!ec->lock_data.lock(&ec->lock_data)) {
		dev_warn(dev, "Failed to acquire mutex");
		return -EBUSY;
		}

		status = asus_ec_block_read(dev, ec);
		@@ -508,10 +577,10 @@ static int update_ec_sensors(const struct device *dev,
		if (!status) {
		update_sensor_values(ec, ec->read_buffer);
		}
		if (ACPI_FAILURE(acpi_release_mutex(ec->aml_mutex, NULL))) {
		dev_err(dev, "Failed to release AML mutex");
		}
		cleanup:

		if (!ec->lock_data.unlock(&ec->lock_data))
		dev_err(dev, "Failed to release mutex");

		return status;
		}

		@@ -651,6 +720,7 @@ static int __init asus_ec_probe(struct platform_device *pdev)
		enum hwmon_sensor_types type;
		struct device *hwdev;
		unsigned int i;
		int status;

		pboard_info = get_board_info();
		if (!pboard_info)
		@@ -667,6 +737,11 @@ static int __init asus_ec_probe(struct platform_device *pdev)
		ec_data->sensors = devm_kcalloc(dev, ec_data->nr_sensors,
		sizeof(struct ec_sensor), GFP_KERNEL);

		status = setup_lock_data(dev);
		if (status) {
		dev_err(dev, "Failed to setup state/EC locking: %d", status);
		return status;
		}
		setup_sensor_data(ec_data);
		ec_data->registers = devm_kcalloc(dev, ec_data->nr_registers,
		sizeof(u16), GFP_KERNEL);
		@@ -678,8 +753,6 @@ static int __init asus_ec_probe(struct platform_device *pdev)

		fill_ec_registers(ec_data);

		ec_data->aml_mutex = asus_hw_access_mutex(dev);

		for (i = 0; i < ec_data->nr_sensors; ++i) {
		si = get_sensor_info(ec_data, i);
		if (!nr_count[si->type])