On Mon, Jun 06, 2016 at 04:12:03PM +0200, Andrew Jones wrote:
> > +phys_addr_t pci_bar_size(pcidevaddr_t dev, int bar_num)
> > {
> > uint32_t bar = pci_config_readl(dev, PCI_BASE_ADDRESS_0 + bar_num * 4);
> > + phys_addr_t size = (int32_t)pci_bar_size32(dev, bar_num);
> > + phys_addr_t mask = (int32_t)pci_bar_mask(bar);
> >
> > - if (bar & PCI_BASE_ADDRESS_SPACE_IO)
> > - return bar & PCI_BASE_ADDRESS_IO_MASK;
> > - else
> > - return bar & PCI_BASE_ADDRESS_MEM_MASK;
> > + if (pci_bar_is64(dev, bar_num)) {
> > + uint32_t size_high = pci_bar_size32(dev, bar_num + 1);
> > + size = ((phys_addr_t)size_high << 32) | (uint32_t)size;
> > + }
> > +
> > + return (~(size & mask)) + 1;
>
> All this casting of size and mask is pointless. Please rework it
> similar to what I did above.
This is the most compact and straight variant I was able to come up with:
uint32_t bar = pci_bar_get(dev, bar_num);
phys_addr_t size = (int32_t)pci_bar_size32(dev, bar_num);
phys_addr_t mask = (int32_t)pci_bar_mask(bar);
if (pci_bar_is64(dev, bar_num))
size |= (phys_addr_t)pci_bar_size32(dev, bar_num + 1) << 32;
return (~(size & mask)) + 1;
The casting is needed to avoid putting explicitly all 1s into higher
bits of size and/or mask. Otherwise (~(size & mask)) + 1 expression would
not bring correct results. I really struggle to make something better
readable.
> Thanks,
> drew
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