Skip to content

Commit

Permalink
hwmon: (dell-smm) Prepare for multiple SMM calling backends
Browse files Browse the repository at this point in the history 
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: <serverror@serverror.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20231123004820.50635-2-W_Armin@gmx.de
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
  • Loading branch information
Armin Wolf authored and Guenter Roeck committed Dec 11, 2023
1 parent c9ba592 commit 744f7be
Showing 1 changed file with 79 additions and 52 deletions.
131 changes: 79 additions & 52 deletions drivers/hwmon/dell-smm-hwmon.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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];
Expand All @@ -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 {
Expand Down Expand Up @@ -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",
Expand Down Expand Up @@ -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)
Expand All @@ -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;
Expand All @@ -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;

Expand All @@ -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.
*/
Expand All @@ -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;
}

/*
Expand All @@ -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;
}

/*
Expand All @@ -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)
Expand All @@ -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);
}

/*
Expand All @@ -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);
}

/*
Expand All @@ -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.
Expand All @@ -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.
Expand All @@ -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;

Expand All @@ -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;

Expand All @@ -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;

Expand Down Expand Up @@ -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:
Expand Down Expand Up @@ -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;

Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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;

Expand Down Expand Up @@ -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;

Expand Down Expand Up @@ -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) {
Expand Down Expand Up @@ -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;

Expand Down

0 comments on commit 744f7be

Please sign in to comment.