hwmon: (fam15h_power) Refactor attributes for dynamically added

Attributes depend on the CPU model the driver gets loaded on.
Therefore, add those attributes dynamically at init time. This is more
flexible to control the different attributes on different platforms.
Suggested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Huang Rui <ray.huang@amd.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

drivers/hwmon/fam15h_power.c

@@ -41,12 +41,17 @@ MODULE_LICENSE("GPL");
 #define REG_TDP_RUNNING_AVERAGE		0xe0
 #define REG_TDP_LIMIT3			0xe8
 
+#define FAM15H_MIN_NUM_ATTRS		2
+#define FAM15H_NUM_GROUPS		2
+
 struct fam15h_power_data {
 	struct pci_dev *pdev;
 	unsigned int tdp_to_watts;
 	unsigned int base_tdp;
 	unsigned int processor_pwr_watts;
 	unsigned int cpu_pwr_sample_ratio;
+	const struct attribute_group *groups[FAM15H_NUM_GROUPS];
+	struct attribute_group group;
 };
 
 static ssize_t show_power(struct device *dev,
@@ -105,29 +110,31 @@ static ssize_t show_power_crit(struct device *dev,
 }
 static DEVICE_ATTR(power1_crit, S_IRUGO, show_power_crit, NULL);
 
-static umode_t fam15h_power_is_visible(struct kobject *kobj,
-				       struct attribute *attr,
-				       int index)
+static int fam15h_power_init_attrs(struct pci_dev *pdev,
+				   struct fam15h_power_data *data)
 {
-	/* power1_input is only reported for Fam15h, Models 00h-0fh */
-	if (attr == &dev_attr_power1_input.attr &&
-	   (boot_cpu_data.x86 != 0x15 || boot_cpu_data.x86_model > 0xf))
-		return 0;
+	int n = FAM15H_MIN_NUM_ATTRS;
+	struct attribute **fam15h_power_attrs;
 
-	return attr->mode;
-}
+	if (boot_cpu_data.x86 == 0x15 && boot_cpu_data.x86_model <= 0xf)
+		n += 1;
 
-static struct attribute *fam15h_power_attrs[] = {
-	&dev_attr_power1_input.attr,
-	&dev_attr_power1_crit.attr,
-	NULL
-};
+	fam15h_power_attrs = devm_kcalloc(&pdev->dev, n,
+					  sizeof(*fam15h_power_attrs),
+					  GFP_KERNEL);
 
-static const struct attribute_group fam15h_power_group = {
-	.attrs = fam15h_power_attrs,
-	.is_visible = fam15h_power_is_visible,
-};
-__ATTRIBUTE_GROUPS(fam15h_power);
+	if (!fam15h_power_attrs)
+		return -ENOMEM;
+
+	n = 0;
+	fam15h_power_attrs[n++] = &dev_attr_power1_crit.attr;
+	if (boot_cpu_data.x86 == 0x15 && boot_cpu_data.x86_model <= 0xf)
+		fam15h_power_attrs[n++] = &dev_attr_power1_input.attr;
+
+	data->group.attrs = fam15h_power_attrs;
+
+	return 0;
+}
 
 static bool should_load_on_this_node(struct pci_dev *f4)
 {
@@ -186,11 +193,12 @@ static int fam15h_power_resume(struct pci_dev *pdev)
 #define fam15h_power_resume NULL
 #endif
 
-static void fam15h_power_init_data(struct pci_dev *f4,
-					     struct fam15h_power_data *data)
+static int fam15h_power_init_data(struct pci_dev *f4,
+				  struct fam15h_power_data *data)
 {
 	u32 val, eax, ebx, ecx, edx;
 	u64 tmp;
+	int ret;
 
 	pci_read_config_dword(f4, REG_PROCESSOR_TDP, &val);
 	data->base_tdp = val >> 16;
@@ -211,11 +219,15 @@ static void fam15h_power_init_data(struct pci_dev *f4,
 	/* convert to microWatt */
 	data->processor_pwr_watts = (tmp * 15625) >> 10;
 
+	ret = fam15h_power_init_attrs(f4, data);
+	if (ret)
+		return ret;
+
 	cpuid(0x80000007, &eax, &ebx, &ecx, &edx);
 
 	/* CPUID Fn8000_0007:EDX[12] indicates to support accumulated power */
 	if (!(edx & BIT(12)))
-		return;
+		return 0;
 
 	/*
 	 * determine the ratio of the compute unit power accumulator
@@ -223,14 +235,17 @@ static void fam15h_power_init_data(struct pci_dev *f4,
 	 * Fn8000_0007:ECX
 	 */
 	data->cpu_pwr_sample_ratio = ecx;
+
+	return 0;
 }
 
 static int fam15h_power_probe(struct pci_dev *pdev,
-					const struct pci_device_id *id)
+			      const struct pci_device_id *id)
 {
 	struct fam15h_power_data *data;
 	struct device *dev = &pdev->dev;
 	struct device *hwmon_dev;
+	int ret;
 
 	/*
 	 * though we ignore every other northbridge, we still have to
@@ -246,12 +261,17 @@ static int fam15h_power_probe(struct pci_dev *pdev,
 	if (!data)
 		return -ENOMEM;
 
-	fam15h_power_init_data(pdev, data);
+	ret = fam15h_power_init_data(pdev, data);
+	if (ret)
+		return ret;
+
 	data->pdev = pdev;
 
+	data->groups[0] = &data->group;
+
 	hwmon_dev = devm_hwmon_device_register_with_groups(dev, "fam15h_power",
 							   data,
-							   fam15h_power_groups);
+							   &data->groups[0]);
 	return PTR_ERR_OR_ZERO(hwmon_dev);
 }