[PATCH v3 3/3] PCI: ARM: add support for generic PCI host controller
Will Deacon
will.deacon at arm.com
Tue Feb 18 14:10:23 EST 2014
On Tue, Feb 18, 2014 at 01:46:44PM +0000, Arnd Bergmann wrote:
> On Tuesday 18 February 2014 12:20:43 Will Deacon wrote:
>
> > +static int gen_pci_alloc_io_offset(u32 sz, resource_size_t *offset)
> > +{
> > + static DECLARE_BITMAP(io_map, (IO_SPACE_LIMIT + 1) / SZ_64K);
> > + int idx, num_wins;
> > +
> > + if (sz > SZ_64K)
> > + return -ENOSPC;
> > +
> > + num_wins = (IO_SPACE_LIMIT + 1) / SZ_64K;
> > + idx = 0;
> > + do {
> > + idx = find_next_zero_bit(io_map, num_wins, idx);
> > + if (idx == num_wins)
> > + return -ENOSPC;
> > + } while (test_and_set_bit(idx, io_map));
> > +
> > + *offset = idx * SZ_64K;
> > + return 0;
> > +}
>
> Sicne you're always starting the search at 0 and you never free
> the map, this is essentially the same as remembering the last number
> that was used and using the next one, right?
Yes, I can implement that easily enough. I was wondering if there was a case
for allowing windows to be freed, but it doesn't feel especially compelling.
> You should also pass the rang->pci_addr here to calculate the
> offset in case the pci_addr is not zero.
>
> > + /* Register our I/O and Memory resources */
> > + res_valid = 0;
> > + list_for_each_entry(win, &pci->host.windows, list) {
> > + struct resource *parent;
> > +
> > + if (resource_type(win->res) == IORESOURCE_IO) {
> > + parent = &ioport_resource;
> > + err = pci_ioremap_io(win->offset, win->res->start);
>
> and consequently pass the pci_addr rather than the offset here. How about
> moving the pci_ioremap_io() call into gen_pci_alloc_io_offset()?
Can do.
Thanks for the feedback.
Will
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