Commit 744f7be3 authored by Armin Wolf's avatar Armin Wolf Committed by Guenter Roeck
Browse files

hwmon: (dell-smm) Prepare for multiple SMM calling backends 



Modern Dell machines support multiple ways to issue an SMM call.
Prepare support for those by introducing dell_smm_ops, which is
used by dell_smm_call() to perform a SMM call. Each SMM backend
needs to provide a dell_smm_ops structure.

Tested-by: default avatar <serverror@serverror.com>
Reviewed-by: default avatarHans de Goede <hdegoede@redhat.com>
Reviewed-by: default avatarPali Rohár <pali@kernel.org>
Signed-off-by: default avatarArmin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20231123004820.50635-2-W_Armin@gmx.de


Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent c9ba5925

drivers/hwmon/dell-smm-hwmon.c

+79 −52
Original line number Diff line number Diff line
@@ -69,6 +69,20 @@ 
#define DELL_SMM_NO_TEMP	10

#define DELL_SMM_NO_FANS	3



struct smm_regs {

	unsigned int eax;

	unsigned int ebx;

	unsigned int ecx;

	unsigned int edx;

	unsigned int esi;

	unsigned int edi;

};



struct dell_smm_ops {

	struct device *smm_dev;

	int (*smm_call)(struct device *smm_dev, struct smm_regs *regs);

};



struct dell_smm_data {

	struct mutex i8k_mutex; /* lock for sensors writes */

	char bios_version[4];
@@ -84,6 +98,7 @@ struct dell_smm_data { 
	bool fan[DELL_SMM_NO_FANS];

	int fan_type[DELL_SMM_NO_FANS];

	int *fan_nominal_speed[DELL_SMM_NO_FANS];

	const struct dell_smm_ops *ops;

};



struct dell_smm_cooling_data {
@@ -123,15 +138,6 @@ static uint fan_max; 
module_param(fan_max, uint, 0);

MODULE_PARM_DESC(fan_max, "Maximum configurable fan speed (default: autodetect)");



struct smm_regs {

	unsigned int eax;

	unsigned int ebx;

	unsigned int ecx;

	unsigned int edx;

	unsigned int esi;

	unsigned int edi;

};



static const char * const temp_labels[] = {

	"CPU",

	"GPU",
@@ -171,12 +177,8 @@ static inline const char __init *i8k_get_dmi_data(int field) 
 */

static int i8k_smm_func(void *par)

{

	ktime_t calltime = ktime_get();

	struct smm_regs *regs = par;

	int eax = regs->eax;

	int ebx = regs->ebx;

	unsigned char carry;

	long long duration;



	/* SMM requires CPU 0 */

	if (smp_processor_id() != 0)
@@ -193,14 +195,7 @@ static int i8k_smm_func(void *par) 
		       "+S" (regs->esi),

		       "+D" (regs->edi));



	duration = ktime_us_delta(ktime_get(), calltime);

	pr_debug("smm(0x%.4x 0x%.4x) = 0x%.4x carry: %d (took %7lld usecs)\n",

		 eax, ebx, regs->eax & 0xffff, carry, duration);



	if (duration > DELL_SMM_MAX_DURATION)

		pr_warn_once("SMM call took %lld usecs!\n", duration);



	if (carry || (regs->eax & 0xffff) == 0xffff || regs->eax == eax)

	if (carry)

		return -EINVAL;



	return 0;
@@ -209,7 +204,7 @@ static int i8k_smm_func(void *par) 
/*

 * Call the System Management Mode BIOS.

 */

static int i8k_smm(struct smm_regs *regs)

static int i8k_smm_call(struct device *dummy, struct smm_regs *regs)

{

	int ret;
@@ -220,6 +215,37 @@ static int i8k_smm(struct smm_regs *regs) 
	return ret;

}



static const struct dell_smm_ops i8k_smm_ops = {

	.smm_call = i8k_smm_call,

};



static int dell_smm_call(const struct dell_smm_ops *ops, struct smm_regs *regs)

{

	unsigned int eax = regs->eax;

	unsigned int ebx = regs->ebx;

	long long duration;

	ktime_t calltime;

	int ret;



	calltime = ktime_get();

	ret = ops->smm_call(ops->smm_dev, regs);

	duration = ktime_us_delta(ktime_get(), calltime);



	pr_debug("SMM(0x%.4x 0x%.4x) = 0x%.4x status: %d (took %7lld usecs)\n",

		 eax, ebx, regs->eax & 0xffff, ret, duration);



	if (duration > DELL_SMM_MAX_DURATION)

		pr_warn_once("SMM call took %lld usecs!\n", duration);



	if (ret < 0)

		return ret;



	if ((regs->eax & 0xffff) == 0xffff || regs->eax == eax)

		return -EINVAL;



	return 0;

}



/*

 * Read the fan status.

 */
@@ -233,7 +259,7 @@ static int i8k_get_fan_status(const struct dell_smm_data *data, u8 fan) 
	if (data->disallow_fan_support)

		return -EINVAL;



	return i8k_smm(&regs) ? : regs.eax & 0xff;

	return dell_smm_call(data->ops, &regs) ? : regs.eax & 0xff;

}



/*
@@ -249,7 +275,7 @@ static int i8k_get_fan_speed(const struct dell_smm_data *data, u8 fan) 
	if (data->disallow_fan_support)

		return -EINVAL;



	return i8k_smm(&regs) ? : (regs.eax & 0xffff) * data->i8k_fan_mult;

	return dell_smm_call(data->ops, &regs) ? : (regs.eax & 0xffff) * data->i8k_fan_mult;

}



/*
@@ -265,7 +291,7 @@ static int _i8k_get_fan_type(const struct dell_smm_data *data, u8 fan) 
	if (data->disallow_fan_support || data->disallow_fan_type_call)

		return -EINVAL;



	return i8k_smm(&regs) ? : regs.eax & 0xff;

	return dell_smm_call(data->ops, &regs) ? : regs.eax & 0xff;

}



static int i8k_get_fan_type(struct dell_smm_data *data, u8 fan)
@@ -290,7 +316,7 @@ static int __init i8k_get_fan_nominal_speed(const struct dell_smm_data *data, u8 
	if (data->disallow_fan_support)

		return -EINVAL;



	return i8k_smm(&regs) ? : (regs.eax & 0xffff);

	return dell_smm_call(data->ops, &regs) ? : (regs.eax & 0xffff);

}



/*
@@ -304,7 +330,7 @@ static int i8k_enable_fan_auto_mode(const struct dell_smm_data *data, bool enabl 
		return -EINVAL;



	regs.eax = enable ? data->auto_fan : data->manual_fan;

	return i8k_smm(&regs);

	return dell_smm_call(data->ops, &regs);

}



/*
@@ -320,35 +346,35 @@ static int i8k_set_fan(const struct dell_smm_data *data, u8 fan, int speed) 
	speed = (speed < 0) ? 0 : ((speed > data->i8k_fan_max) ? data->i8k_fan_max : speed);

	regs.ebx = fan | (speed << 8);



	return i8k_smm(&regs);

	return dell_smm_call(data->ops, &regs);

}



static int __init i8k_get_temp_type(u8 sensor)

static int __init i8k_get_temp_type(const struct dell_smm_data *data, u8 sensor)

{

	struct smm_regs regs = {

		.eax = I8K_SMM_GET_TEMP_TYPE,

		.ebx = sensor,

	};



	return i8k_smm(&regs) ? : regs.eax & 0xff;

	return dell_smm_call(data->ops, &regs) ? : regs.eax & 0xff;

}



/*

 * Read the cpu temperature.

 */

static int _i8k_get_temp(u8 sensor)

static int _i8k_get_temp(const struct dell_smm_data *data, u8 sensor)

{

	struct smm_regs regs = {

		.eax = I8K_SMM_GET_TEMP,

		.ebx = sensor,

	};



	return i8k_smm(&regs) ? : regs.eax & 0xff;

	return dell_smm_call(data->ops, &regs) ? : regs.eax & 0xff;

}



static int i8k_get_temp(u8 sensor)

static int i8k_get_temp(const struct dell_smm_data *data, u8 sensor)

{

	int temp = _i8k_get_temp(sensor);

	int temp = _i8k_get_temp(data, sensor);



	/*

	 * Sometimes the temperature sensor returns 0x99, which is out of range.
@@ -359,7 +385,7 @@ static int i8k_get_temp(u8 sensor) 
	 */

	if (temp == 0x99) {

		msleep(100);

		temp = _i8k_get_temp(sensor);

		temp = _i8k_get_temp(data, sensor);

	}

	/*

	 * Return -ENODATA for all invalid temperatures.
@@ -375,12 +401,12 @@ static int i8k_get_temp(u8 sensor) 
	return temp;

}



static int __init i8k_get_dell_signature(int req_fn)

static int __init dell_smm_get_signature(const struct dell_smm_ops *ops, int req_fn)

{

	struct smm_regs regs = { .eax = req_fn, };

	int rc;



	rc = i8k_smm(&regs);

	rc = dell_smm_call(ops, &regs);

	if (rc < 0)

		return rc;
@@ -392,12 +418,12 @@ static int __init i8k_get_dell_signature(int req_fn) 
/*

 * Read the Fn key status.

 */

static int i8k_get_fn_status(void)

static int i8k_get_fn_status(const struct dell_smm_data *data)

{

	struct smm_regs regs = { .eax = I8K_SMM_FN_STATUS, };

	int rc;



	rc = i8k_smm(&regs);

	rc = dell_smm_call(data->ops, &regs);

	if (rc < 0)

		return rc;
@@ -416,12 +442,12 @@ static int i8k_get_fn_status(void) 
/*

 * Read the power status.

 */

static int i8k_get_power_status(void)

static int i8k_get_power_status(const struct dell_smm_data *data)

{

	struct smm_regs regs = { .eax = I8K_SMM_POWER_STATUS, };

	int rc;



	rc = i8k_smm(&regs);

	rc = dell_smm_call(data->ops, &regs);

	if (rc < 0)

		return rc;
@@ -464,15 +490,15 @@ static long i8k_ioctl(struct file *fp, unsigned int cmd, unsigned long arg) 


		return 0;

	case I8K_FN_STATUS:

		val = i8k_get_fn_status();

		val = i8k_get_fn_status(data);

		break;



	case I8K_POWER_STATUS:

		val = i8k_get_power_status();

		val = i8k_get_power_status(data);

		break;



	case I8K_GET_TEMP:

		val = i8k_get_temp(0);

		val = i8k_get_temp(data, 0);

		break;



	case I8K_GET_SPEED:
@@ -539,14 +565,14 @@ static int i8k_proc_show(struct seq_file *seq, void *offset) 
	int fn_key, cpu_temp, ac_power;

	int left_fan, right_fan, left_speed, right_speed;



	cpu_temp	= i8k_get_temp(0);				/* 11100 µs */

	cpu_temp	= i8k_get_temp(data, 0);			/* 11100 µs */

	left_fan	= i8k_get_fan_status(data, I8K_FAN_LEFT);	/*   580 µs */

	right_fan	= i8k_get_fan_status(data, I8K_FAN_RIGHT);	/*   580 µs */

	left_speed	= i8k_get_fan_speed(data, I8K_FAN_LEFT);	/*   580 µs */

	right_speed	= i8k_get_fan_speed(data, I8K_FAN_RIGHT);	/*   580 µs */

	fn_key		= i8k_get_fn_status();				/*   750 µs */

	fn_key		= i8k_get_fn_status(data);			/*   750 µs */

	if (power_status)

		ac_power = i8k_get_power_status();			/* 14700 µs */

		ac_power = i8k_get_power_status(data);			/* 14700 µs */

	else

		ac_power = -1;
@@ -665,7 +691,7 @@ static umode_t dell_smm_is_visible(const void *drvdata, enum hwmon_sensor_types 
		switch (attr) {

		case hwmon_temp_input:

			/* _i8k_get_temp() is fine since we do not care about the actual value */

			if (data->temp_type[channel] >= 0 || _i8k_get_temp(channel) >= 0)

			if (data->temp_type[channel] >= 0 || _i8k_get_temp(data, channel) >= 0)

				return 0444;



			break;
@@ -747,7 +773,7 @@ static int dell_smm_read(struct device *dev, enum hwmon_sensor_types type, u32 a 
	case hwmon_temp:

		switch (attr) {

		case hwmon_temp_input:

			ret = i8k_get_temp(channel);

			ret = i8k_get_temp(data, channel);

			if (ret < 0)

				return ret;
@@ -994,7 +1020,7 @@ static int __init dell_smm_init_hwmon(struct device *dev) 
	u8 i;



	for (i = 0; i < DELL_SMM_NO_TEMP; i++) {

		data->temp_type[i] = i8k_get_temp_type(i);

		data->temp_type[i] = i8k_get_temp_type(data, i);

		if (data->temp_type[i] < 0)

			continue;
@@ -1353,6 +1379,7 @@ static int __init dell_smm_probe(struct platform_device *pdev) 


	mutex_init(&data->i8k_mutex);

	platform_set_drvdata(pdev, data);

	data->ops = &i8k_smm_ops;



	if (dmi_check_system(i8k_blacklist_fan_support_dmi_table)) {

		if (!force) {
@@ -1445,8 +1472,8 @@ static int __init i8k_init(void) 
	/*

	 * Get SMM Dell signature

	 */

	if (i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG1) &&

	    i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG2)) {

	if (dell_smm_get_signature(&i8k_smm_ops, I8K_SMM_GET_DELL_SIG1) &&

	    dell_smm_get_signature(&i8k_smm_ops, I8K_SMM_GET_DELL_SIG2)) {

		if (!force)

			return -ENODEV;