Hello,
> > > The alternative would be separate llseek callbacks for both the legacy
> > > and resource attributes, which we can add if this would be the preference
> > > here.
> >
> > If we were to do this, then it would be as follows:
> >
> > static loff_t pci_llseek_resource(struct file *filep,
> > struct kobject *kobj,
> > const struct bin_attribute *attr,
> > loff_t offset, int whence)
> > {
> > struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
> > int bar = (unsigned long)attr->private;
> >
> > return fixed_size_llseek(filep, offset, whence,
> > pci_resource_len(pdev, bar));
> > }
> >
> > static loff_t pci_llseek_resource_legacy(struct file *filep,
> > struct kobject *kobj
> > __always_unused,
> > const struct bin_attribute *attr,
> > loff_t offset, int whence)
> > {
> > return fixed_size_llseek(filep, offset, whence, attr->size);
> > }
> >
> > Each callback would be placed within the corresponding #ifdef block, so one
> > for HAVE_PCI_MMAP or ARCH_GENERIC_PCI_MMAP_RESOURCE, and the other for the
> > legacy attributes, so behind the HAVE_PCI_LEGACY guard.
> >
> > Note, the names need to be different, as some architectures offer both
> > type of resource files, like PowerPC, which defines both the HAVE_PCI_LEGACY
> > and HAVE_PCI_MMAP.
> >
> > With this split, we can also drop the __maybe_unused annotation.
> >
> > While I wanted to keep the changes to only what was needed for the
> > pci_llseek_resource() to cover both type of resources, it would be
> > also fine to have two distinct callbacks, too.
>
> Yes, I think this is much more readable than the "if (attr->size)"
> check.
OK. I will switch to two llseek callbacks in the next version.
Thank you,
Krzysztof
