Re: [PATCH 2/4] PCI: Add pci_rebar_bytes_to_size()

[Bjorn Helgaas <helgaas@kernel.org>]

On Thu, Jan 07, 2021 at 11:31:36PM +0000, Darren Salt wrote:
> I demand that Bjorn Helgaas may or may not have written...

?

> >> +static inline int pci_rebar_bytes_to_size(u64 bytes)
> >> +{
> >> +	bytes = roundup_pow_of_two(bytes);
> >> +	return max(ilog2(bytes), 20) - 20;
> 
> > This isn't returning a "size", is it?  It looks like it's returning the
> > log2 of the number of MB the BAR will be, i.e., the encoding used by the
> > Resizable BAR Control register "BAR Size" field.  Needs a brief comment to
> > that effect and/or a different function name.
> 
> Given that, it seems to me that pci_rebar_size_to_bytes should be similarly
> commented and/or renamed.

Makes sense.  Something like this is sufficient:

  return 1ULL << (size + 20);  /* Convert PCI_REBAR_CTRL "BAR Size" */