Messages in this thread | | | Date | Tue, 7 Jun 2016 18:56:14 -0500 | From | Bjorn Helgaas <> | Subject | Re: [PATCH V8 4/9] acpi, pci: Support IO resources when parsing PCI host bridge resources. |
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On Mon, May 30, 2016 at 05:14:17PM +0200, Tomasz Nowicki wrote: > Platforms that have memory mapped IO port (such as ARM64) need special > handling for PCI I/O resources. For host bridge's resource probing case > these resources need to be fixed up with pci_register_io_range/pci_remap_iospace etc. > > The same I/O resources need to be released after hotplug > removal so that it can be re-added back by the pci_remap_iospace > function during insertion. As a consequence we unmap I/O resources > with pci_unmap_iospace when we release host bridge resources. > > Signed-off-by: Jayachandran C <jchandra@broadcom.com> > Signed-off-by: Sinan Kaya <okaya@codeaurora.org> > Signed-off-by: Tomasz Nowicki <tn@semihalf.com> > --- > drivers/acpi/pci_root.c | 39 +++++++++++++++++++++++++++++++++++++++ > 1 file changed, 39 insertions(+) > > diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c > index ae3fe4e..ee3b728 100644 > --- a/drivers/acpi/pci_root.c > +++ b/drivers/acpi/pci_root.c > @@ -720,6 +720,40 @@ next: > } > } > > +#ifdef PCI_IOBASE > +static void acpi_pci_root_remap_iospace(struct resource_entry *entry) > +{ > + struct resource *res = entry->res; > + resource_size_t cpu_addr = res->start; > + resource_size_t pci_addr = cpu_addr - entry->offset; > + resource_size_t length = resource_size(res); > + unsigned long port; > + > + if (pci_register_io_range(cpu_addr, length)) > + goto err; > + > + port = pci_address_to_pio(cpu_addr); > + if (port == (unsigned long)-1) > + goto err; > + > + res->start = port; > + res->end = port + length - 1; > + entry->offset = port - pci_addr; > + > + if (pci_remap_iospace(res, cpu_addr) < 0) > + goto err; > + > + pr_info("Remapped I/O %pa to %pR\n", &cpu_addr, res); > + return; > +err: > + res->flags |= IORESOURCE_DISABLED;
Trivial, but I might write this as:
res->flags |= IORESOURCE_DISABLED; if (pci_register_io_range(cpu_addr, length)) return; ... if (pci_remap_iospace(res, cpu_addr) < 0) return;
res->flags &= ~IORESOURCE_DISABLED; pr_info("Remapped I/O %pa to %pR\n", &cpu_addr, res); }
to get rid of the gotos. But I dunno, it's a little ugly to fiddle with res->flags in the case where everything succeeds.
> +} > +#else > +static void acpi_pci_root_remap_iospace(struct resource_entry *entry) > +{ > +} > +#endif
Rafael's code here, and I know he had an earlier comment about in-function #ifdefs, so I don't know what he thinks here. To me, it would be simpler to move this ifdef inside so we don't have to repeat the function signature.
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