On 1/3/2018 6:08 PM, Bjorn Helgaas wrote:
> Hi Stuart,
>
> Please run "git log --oneline drivers/pci/pci-sysfs.c" and follow the
> convention.
>
Bjorn,
Is the problem just with the subject line (i.e., it should be something like "PCI: Expose ari_enabled...")?
I'm happy to fix, I just want to make sure I understand the problem so I get it right next time.
Thank you,
Stuart
> On Wed, Jan 03, 2018 at 10:36:46AM -0600, Stuart Hayes wrote:
>> Some multifunction PCI devices with more than 8 functions use "alternative
>> routing-ID interpretation" (ARI), which means the 8-bit device/function
>> number field will be interpreted as 8 bits specifying the function number
>> (the device number is 0 implicitly), rather than the upper 5 bits
>> specifying the device number and the lower 3 bits specifying the function
>> number. The kernel can enable and use this.
>>
>> Expose in a sysfs attribute whether the kernel has enabled ARI, so that a
>> program in userspace won't have to parse PCI devices and PCI configuration
>> space to figure out if it is enabled. This will allow better predictable
>> network naming using PCI function numbers without using PCI bus or device
>> numbers, which is desirable because bus and device numbers can change with
>> system configuration but function numbers will not.
>>
>> Signed-off-by: Stuart Hayes <stuart.w.hayes@xxxxxxxxx>
>> ---
>>
>> --- linux-4.15-rc6/drivers/pci/pci-sysfs.c.orig 2017-12-31 17:47:43.000000000 -0500
>> +++ linux-4.15-rc6/drivers/pci/pci-sysfs.c 2018-01-02 13:58:23.372928377 -0500
>> @@ -278,6 +278,16 @@ static ssize_t subordinate_bus_number_sh
>> }
>> static DEVICE_ATTR_RO(subordinate_bus_number);
>>
>> +static ssize_t ari_enabled_show(struct device *dev,
>> + struct device_attribute *attr,
>> + char *buf)
>> +{
>> + struct pci_dev *pci_dev = to_pci_dev(dev);
>> +
>> + return sprintf(buf, "%u\n", pci_ari_enabled(pci_dev->bus));
>> +}
>> +static DEVICE_ATTR_RO(ari_enabled);
>> +
>> static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
>> char *buf)
>> {
>> @@ -786,6 +796,7 @@ static struct attribute *pci_dev_attrs[]
>> &dev_attr_devspec.attr,
>> #endif
>> &dev_attr_driver_override.attr,
>> + &dev_attr_ari_enabled.attr,
>> NULL,
>> };
>>
>>
>>
>> ---
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