hwmon: (dell-smm) Move blacklist handling to module init

Future SMM calling backends will not be able to probe during
module init, meaning the DMI tables used for backlisting broken
features would have to drop their __initconst attribute.
Prevent this by moving the blacklist handling to module init.

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/20231123004820.50635-3-W_Armin@gmx.deSigned-off-by: Guenter Roeck <linux@roeck-us.net>

drivers/hwmon/dell-smm-hwmon.c

@@ -90,8 +90,6 @@ struct dell_smm_data {
 	uint i8k_fan_mult;
 	uint i8k_pwm_mult;
 	uint i8k_fan_max;
-	bool disallow_fan_type_call;
-	bool disallow_fan_support;
 	unsigned int manual_fan;
 	unsigned int auto_fan;
 	int temp_type[DELL_SMM_NO_TEMP];
@@ -138,6 +136,8 @@ static uint fan_max;
 module_param(fan_max, uint, 0);
 MODULE_PARM_DESC(fan_max, "Maximum configurable fan speed (default: autodetect)");
 
+static bool disallow_fan_type_call, disallow_fan_support;
+
 static const char * const temp_labels[] = {
 	"CPU",
 	"GPU",
@@ -256,7 +256,7 @@ static int i8k_get_fan_status(const struct dell_smm_data *data, u8 fan)
 		.ebx = fan,
 	};
 
-	if (data->disallow_fan_support)
+	if (disallow_fan_support)
 		return -EINVAL;
 
 	return dell_smm_call(data->ops, &regs) ? : regs.eax & 0xff;
@@ -272,7 +272,7 @@ static int i8k_get_fan_speed(const struct dell_smm_data *data, u8 fan)
 		.ebx = fan,
 	};
 
-	if (data->disallow_fan_support)
+	if (disallow_fan_support)
 		return -EINVAL;
 
 	return dell_smm_call(data->ops, &regs) ? : (regs.eax & 0xffff) * data->i8k_fan_mult;
@@ -288,7 +288,7 @@ static int _i8k_get_fan_type(const struct dell_smm_data *data, u8 fan)
 		.ebx = fan,
 	};
 
-	if (data->disallow_fan_support || data->disallow_fan_type_call)
+	if (disallow_fan_support || disallow_fan_type_call)
 		return -EINVAL;
 
 	return dell_smm_call(data->ops, &regs) ? : regs.eax & 0xff;
@@ -313,7 +313,7 @@ static int __init i8k_get_fan_nominal_speed(const struct dell_smm_data *data, u8
 		.ebx = fan | (speed << 8),
 	};
 
-	if (data->disallow_fan_support)
+	if (disallow_fan_support)
 		return -EINVAL;
 
 	return dell_smm_call(data->ops, &regs) ? : (regs.eax & 0xffff);
@@ -326,7 +326,7 @@ static int i8k_enable_fan_auto_mode(const struct dell_smm_data *data, bool enabl
 {
 	struct smm_regs regs = { };
 
-	if (data->disallow_fan_support)
+	if (disallow_fan_support)
 		return -EINVAL;
 
 	regs.eax = enable ? data->auto_fan : data->manual_fan;
@@ -340,7 +340,7 @@ static int i8k_set_fan(const struct dell_smm_data *data, u8 fan, int speed)
 {
 	struct smm_regs regs = { .eax = I8K_SMM_SET_FAN, };
 
-	if (data->disallow_fan_support)
+	if (disallow_fan_support)
 		return -EINVAL;
 
 	speed = (speed < 0) ? 0 : ((speed > data->i8k_fan_max) ? data->i8k_fan_max : speed);
@@ -705,7 +705,7 @@ static umode_t dell_smm_is_visible(const void *drvdata, enum hwmon_sensor_types
 		}
 		break;
 	case hwmon_fan:
-		if (data->disallow_fan_support)
+		if (disallow_fan_support)
 			break;
 
 		switch (attr) {
@@ -715,7 +715,7 @@ static umode_t dell_smm_is_visible(const void *drvdata, enum hwmon_sensor_types
 
 			break;
 		case hwmon_fan_label:
-			if (data->fan[channel] && !data->disallow_fan_type_call)
+			if (data->fan[channel] && !disallow_fan_type_call)
 				return 0444;
 
 			break;
@@ -731,7 +731,7 @@ static umode_t dell_smm_is_visible(const void *drvdata, enum hwmon_sensor_types
 		}
 		break;
 	case hwmon_pwm:
-		if (data->disallow_fan_support)
+		if (disallow_fan_support)
 			break;
 
 		switch (attr) {
@@ -1381,24 +1381,6 @@ static int __init dell_smm_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, data);
 	data->ops = &i8k_smm_ops;
 
-	if (dmi_check_system(i8k_blacklist_fan_support_dmi_table)) {
-		if (!force) {
-			dev_notice(&pdev->dev, "Disabling fan support due to BIOS bugs\n");
-			data->disallow_fan_support = true;
-		} else {
-			dev_warn(&pdev->dev, "Enabling fan support despite BIOS bugs\n");
-		}
-	}
-
-	if (dmi_check_system(i8k_blacklist_fan_type_dmi_table)) {
-		if (!force) {
-			dev_notice(&pdev->dev, "Disabling fan type call due to BIOS bugs\n");
-			data->disallow_fan_type_call = true;
-		} else {
-			dev_warn(&pdev->dev, "Enabling fan type call despite BIOS bugs\n");
-		}
-	}
-
 	strscpy(data->bios_version, i8k_get_dmi_data(DMI_BIOS_VERSION),
 		sizeof(data->bios_version));
 	strscpy(data->bios_machineid, i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
@@ -1453,6 +1435,27 @@ static struct platform_device *dell_smm_device;
 /*
  * Probe for the presence of a supported laptop.
  */
+static void __init dell_smm_init_dmi(void)
+{
+	if (dmi_check_system(i8k_blacklist_fan_support_dmi_table)) {
+		if (!force) {
+			pr_notice("Disabling fan support due to BIOS bugs\n");
+			disallow_fan_support = true;
+		} else {
+			pr_warn("Enabling fan support despite BIOS bugs\n");
+		}
+	}
+
+	if (dmi_check_system(i8k_blacklist_fan_type_dmi_table)) {
+		if (!force) {
+			pr_notice("Disabling fan type call due to BIOS bugs\n");
+			disallow_fan_type_call = true;
+		} else {
+			pr_warn("Enabling fan type call despite BIOS bugs\n");
+		}
+	}
+}
+
 static int __init i8k_init(void)
 {
 	/*
@@ -1469,6 +1472,8 @@ static int __init i8k_init(void)
 			i8k_get_dmi_data(DMI_BIOS_VERSION));
 	}
 
+	dell_smm_init_dmi();
+
 	/*
 	 * Get SMM Dell signature
 	 */