Re: [PATCH v2 01/10] hwmon: (fam15h_power) Refactor attributes for dynamically added

From: Huang Rui
Date: Sun Oct 25 2015 - 22:14:24 EST


On Fri, Oct 23, 2015 at 06:42:20AM -0700, Guenter Roeck wrote:
> On 10/19/2015 07:28 PM, Huang Rui wrote:
> >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.
> >
> >Suggestedy-by: Borislav Petkov <bp@xxxxxxxxx>
> >Signed-off-by: Huang Rui <ray.huang@xxxxxxx>
> >Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
> >Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> >Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> >---
> > drivers/hwmon/fam15h_power.c | 70 ++++++++++++++++++++++++++++----------------
> > 1 file changed, 45 insertions(+), 25 deletions(-)
> >
> >diff --git a/drivers/hwmon/fam15h_power.c b/drivers/hwmon/fam15h_power.c
> >index e80ee23..41d022e 100644
> >--- a/drivers/hwmon/fam15h_power.c
> >+++ b/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 *fam15h_power_groups[FAM15H_NUM_GROUPS];
> >+ struct attribute_group fam15h_power_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->fam15h_power_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->fam15h_power_groups[0] = &data->fam15h_power_group;
> >+
> > hwmon_dev = devm_hwmon_device_register_with_groups(dev, "fam15h_power",
> > data,
> >- fam15h_power_groups);
> >+ (const struct attribute_group **)&data->fam15h_power_groups);
>
> Why this typecast ? It should not be needed.
>

That's because there will be a warning without the typecast.

Expected 'const struct attribute_group **', but current type is 'const
struct attribute_group * (*)[2]'.

---
CC [M] /home/ray/tip/drivers/hwmon/fam15h_power.o
/home/ray/tip/drivers/hwmon/fam15h_power.c: In function ‘fam15h_power_probe’:
/home/ray/tip/drivers/hwmon/fam15h_power.c:481:11: warning: passing argument 4 of ‘devm_hwmon_device_register_with_groups’ from incompatible pointer type [enabled by default]
&data->fam15h_power_groups);
^
In file included from /home/ray/tip/drivers/hwmon/fam15h_power.c:22:0:
include/linux/hwmon.h:26:1: note: expected ‘const struct attribute_group **’ but argument is of type ‘const struct attribute_group * (*)[2]’
devm_hwmon_device_register_with_groups(struct device *dev, const char *name,
^
---

Thanks,
Rui
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