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: <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>

diff --git a/drivers/hwmon/dell-smm-hwmon.c b/drivers/hwmon/dell-smm-hwmon.c
index 44aaf9b9191d4147a66ec07d3389987a90516c6a..f66bcfd7c330747a838b02c6fb10328382e4a5cb 100644 (file)
--- a/drivers/hwmon/dell-smm-hwmon.c
+++ b/drivers/hwmon/dell-smm-hwmon.c
@@ -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;