[PATCH v3] hwmon: (ibmpowernv) pretty print labels

[PATCH v3] hwmon: (ibmpowernv) pretty print labels

[Cédric Le Goater]

The new OPAL device tree adds a few properties which can be used to add
extra information on the sensor label.

In the case of a cpu core sensor, the firmware exposes the physical 
identifier of the core in the "ibm,pir" property. The driver 
translates this identifier in a linux cpu number and prints out a 
range corresponding to the hardware threads of the core (as they
share the same sensor).

The numbering gives a hint on the localization of the core in the 
system (which socket, which chip). 

Signed-off-by: Cédric Le Goater <clg@fr.ibm.com>
---

 Changes since v2:

 - fix bogus logical cpu retrieval 
 - use 'threads_per_core' to print out cpu range

 Changes since v1:

 - check cpu validity before printing out the attribute label. 
   if invalid, use a "phy" prefix to distinguish a linux cpu 
   number from a physical cpu number. 

 drivers/hwmon/ibmpowernv.c |   43 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

Index: linux.git/drivers/hwmon/ibmpowernv.c
===================================================================
--- linux.git.orig/drivers/hwmon/ibmpowernv.c
+++ linux.git/drivers/hwmon/ibmpowernv.c
@@ -30,6 +30,7 @@
 #include <linux/platform_device.h>
 #include <asm/opal.h>
 #include <linux/err.h>
+#include <asm/cputhreads.h>
 
 #define MAX_ATTR_LEN	32
 #define MAX_LABEL_LEN	64
@@ -110,12 +111,54 @@ static ssize_t show_label(struct device
 	return sprintf(buf, "%s\n", sdata->label);
 }
 
+static int __init get_logical_cpu(unsigned int hwcpu)
+{
+	int cpu;
+
+	for_each_possible_cpu(cpu)
+		if (get_hard_smp_processor_id(cpu) == hwcpu)
+			return cpu;
+
+	pr_err("%s: could not find a cpu with physical id 0x%x\n",
+	       __func__, hwcpu);
+	return -ENOENT;
+}
+
 static void __init make_sensor_label(struct device_node *np,
 		    struct sensor_data *sdata, const char *label)
 {
+	u32 id;
 	size_t n;
 
 	n = snprintf(sdata->label, sizeof(sdata->label), "%s", label);
+
+	/*
+	 * Core temp pretty print
+	 */
+	if (!of_property_read_u32(np, "ibm,pir", &id)) {
+		int cpuid = get_logical_cpu(id);
+
+		if (cpuid >= 0)
+			/*
+			 * The digital thermal sensors are associated
+			 * with a core. Let's print out the range of
+			 * cpu ids corresponding to the hardware
+			 * threads of the core.
+			 */
+			n += snprintf(sdata->label + n,
+				      sizeof(sdata->label) - n, " %d-%d",
+				      cpuid, cpuid + threads_per_core - 1);
+		else
+			n += snprintf(sdata->label + n,
+				      sizeof(sdata->label) - n, " phy%d", id);
+	}
+
+	/*
+	 * Membuffer pretty print
+	 */
+	if (!of_property_read_u32(np, "ibm,chip-id", &id))
+		n += snprintf(sdata->label + n, sizeof(sdata->label) - n,
+			      " %d", id & 0xffff);
 }
 
 static int get_sensor_index_attr(const char *name, u32 *index,

Re: [PATCH v3] hwmon: (ibmpowernv) pretty print labels

[Guenter Roeck]

On 04/08/2015 12:00 AM, Cédric Le Goater wrote:
> The new OPAL device tree adds a few properties which can be used to add
> extra information on the sensor label.
>
> In the case of a cpu core sensor, the firmware exposes the physical
> identifier of the core in the "ibm,pir" property. The driver
> translates this identifier in a linux cpu number and prints out a
> range corresponding to the hardware threads of the core (as they
> share the same sensor).
>
> The numbering gives a hint on the localization of the core in the
> system (which socket, which chip).
>
> Signed-off-by: Cédric Le Goater <clg@fr.ibm.com>
> ---
>
>   Changes since v2:
>
>   - fix bogus logical cpu retrieval
>   - use 'threads_per_core' to print out cpu range
>
>   Changes since v1:
>
>   - check cpu validity before printing out the attribute label.
>     if invalid, use a "phy" prefix to distinguish a linux cpu
>     number from a physical cpu number.
>
>   drivers/hwmon/ibmpowernv.c |   43 +++++++++++++++++++++++++++++++++++++++++++
>   1 file changed, 43 insertions(+)
>
> Index: linux.git/drivers/hwmon/ibmpowernv.c
> ===================================================================
> --- linux.git.orig/drivers/hwmon/ibmpowernv.c
> +++ linux.git/drivers/hwmon/ibmpowernv.c
> @@ -30,6 +30,7 @@
>   #include <linux/platform_device.h>
>   #include <asm/opal.h>
>   #include <linux/err.h>
> +#include <asm/cputhreads.h>
>
>   #define MAX_ATTR_LEN	32
>   #define MAX_LABEL_LEN	64
> @@ -110,12 +111,54 @@ static ssize_t show_label(struct device
>   	return sprintf(buf, "%s\n", sdata->label);
>   }
>
> +static int __init get_logical_cpu(unsigned int hwcpu)
> +{
> +	int cpu;
> +
> +	for_each_possible_cpu(cpu)
> +		if (get_hard_smp_processor_id(cpu) == hwcpu)
> +			return cpu;
> +
> +	pr_err("%s: could not find a cpu with physical id 0x%x\n",
> +	       __func__, hwcpu);

I like moving this into a function, but I really dislike this error
message. If the devicetree data is wrong/bad, the log and the console
will be clogged with that message. And the user will not be able
to do anything about it.

Guenter

> +	return -ENOENT;
> +}
> +
>   static void __init make_sensor_label(struct device_node *np,
>   		    struct sensor_data *sdata, const char *label)
>   {
> +	u32 id;
>   	size_t n;
>
>   	n = snprintf(sdata->label, sizeof(sdata->label), "%s", label);
> +
> +	/*
> +	 * Core temp pretty print
> +	 */
> +	if (!of_property_read_u32(np, "ibm,pir", &id)) {
> +		int cpuid = get_logical_cpu(id);
> +
> +		if (cpuid >= 0)
> +			/*
> +			 * The digital thermal sensors are associated
> +			 * with a core. Let's print out the range of
> +			 * cpu ids corresponding to the hardware
> +			 * threads of the core.
> +			 */
> +			n += snprintf(sdata->label + n,
> +				      sizeof(sdata->label) - n, " %d-%d",
> +				      cpuid, cpuid + threads_per_core - 1);
> +		else
> +			n += snprintf(sdata->label + n,
> +				      sizeof(sdata->label) - n, " phy%d", id);
> +	}
> +
> +	/*
> +	 * Membuffer pretty print
> +	 */
> +	if (!of_property_read_u32(np, "ibm,chip-id", &id))
> +		n += snprintf(sdata->label + n, sizeof(sdata->label) - n,
> +			      " %d", id & 0xffff);
>   }
>
>   static int get_sensor_index_attr(const char *name, u32 *index,
>
>

Re: [PATCH v3] hwmon: (ibmpowernv) pretty print labels

[Cedric Le Goater]

On 04/08/2015 03:26 PM, Guenter Roeck wrote:
> On 04/08/2015 12:00 AM, Cédric Le Goater wrote:
>> The new OPAL device tree adds a few properties which can be used to add
>> extra information on the sensor label.
>>
>> In the case of a cpu core sensor, the firmware exposes the physical
>> identifier of the core in the "ibm,pir" property. The driver
>> translates this identifier in a linux cpu number and prints out a
>> range corresponding to the hardware threads of the core (as they
>> share the same sensor).
>>
>> The numbering gives a hint on the localization of the core in the
>> system (which socket, which chip).
>>
>> Signed-off-by: Cédric Le Goater <clg@fr.ibm.com>
>> ---
>>
>>   Changes since v2:
>>
>>   - fix bogus logical cpu retrieval
>>   - use 'threads_per_core' to print out cpu range
>>
>>   Changes since v1:
>>
>>   - check cpu validity before printing out the attribute label.
>>     if invalid, use a "phy" prefix to distinguish a linux cpu
>>     number from a physical cpu number.
>>
>>   drivers/hwmon/ibmpowernv.c |   43 +++++++++++++++++++++++++++++++++++++++++++
>>   1 file changed, 43 insertions(+)
>>
>> Index: linux.git/drivers/hwmon/ibmpowernv.c
>> ===================================================================
>> --- linux.git.orig/drivers/hwmon/ibmpowernv.c
>> +++ linux.git/drivers/hwmon/ibmpowernv.c
>> @@ -30,6 +30,7 @@
>>   #include <linux/platform_device.h>
>>   #include <asm/opal.h>
>>   #include <linux/err.h>
>> +#include <asm/cputhreads.h>
>>
>>   #define MAX_ATTR_LEN    32
>>   #define MAX_LABEL_LEN    64
>> @@ -110,12 +111,54 @@ static ssize_t show_label(struct device
>>       return sprintf(buf, "%s\n", sdata->label);
>>   }
>>
>> +static int __init get_logical_cpu(unsigned int hwcpu)
>> +{
>> +    int cpu;
>> +
>> +    for_each_possible_cpu(cpu)
>> +        if (get_hard_smp_processor_id(cpu) == hwcpu)
>> +            return cpu;
>> +
>> +    pr_err("%s: could not find a cpu with physical id 0x%x\n",
>> +           __func__, hwcpu);
> 
> I like moving this into a function, but I really dislike this error
> message. If the devicetree data is wrong/bad, the log and the console
> will be clogged with that message. And the user will not be able
> to do anything about it.

yes. It is not super useful anyway and it is redundant with the "phy" 
prefix below. Do you want me to kill it in a v4 ? 

Thanks,

C. 

> 
> Guenter
> 
>> +    return -ENOENT;
>> +}
>> +
>>   static void __init make_sensor_label(struct device_node *np,
>>               struct sensor_data *sdata, const char *label)
>>   {
>> +    u32 id;
>>       size_t n;
>>
>>       n = snprintf(sdata->label, sizeof(sdata->label), "%s", label);
>> +
>> +    /*
>> +     * Core temp pretty print
>> +     */
>> +    if (!of_property_read_u32(np, "ibm,pir", &id)) {
>> +        int cpuid = get_logical_cpu(id);
>> +
>> +        if (cpuid >= 0)
>> +            /*
>> +             * The digital thermal sensors are associated
>> +             * with a core. Let's print out the range of
>> +             * cpu ids corresponding to the hardware
>> +             * threads of the core.
>> +             */
>> +            n += snprintf(sdata->label + n,
>> +                      sizeof(sdata->label) - n, " %d-%d",
>> +                      cpuid, cpuid + threads_per_core - 1);
>> +        else
>> +            n += snprintf(sdata->label + n,
>> +                      sizeof(sdata->label) - n, " phy%d", id);
>> +    }
>> +
>> +    /*
>> +     * Membuffer pretty print
>> +     */
>> +    if (!of_property_read_u32(np, "ibm,chip-id", &id))
>> +        n += snprintf(sdata->label + n, sizeof(sdata->label) - n,
>> +                  " %d", id & 0xffff);
>>   }
>>
>>   static int get_sensor_index_attr(const char *name, u32 *index,
>>
>>
>