On Mon, Jul 14, 2014 at 07:15:48PM +0100, Arnd Bergmann wrote: > On Monday 14 July 2014 17:54:43 Catalin Marinas wrote: > > On Tue, Jul 01, 2014 at 07:43:34PM +0100, Liviu Dudau wrote: > > > Introduce a default implementation for remapping PCI bus I/O resources > > > onto the CPU address space. Architectures with special needs may > > > provide their own version, but most should be able to use this one. > > [...] > > > +/** > > > + * pci_remap_iospace - Remap the memory mapped I/O space > > > + * @res: Resource describing the I/O space > > > + * @phys_addr: physical address where the range will be mapped. > > > + * > > > + * Remap the memory mapped I/O space described by the @res > > > + * into the CPU physical address space. Only architectures > > > + * that have memory mapped IO defined (and hence PCI_IOBASE) > > > + * should call this function. > > > + */ > > > +int __weak pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr) > > > +{ > > > + int err = -ENODEV; > > > + > > > +#ifdef PCI_IOBASE > > > + if (!(res->flags & IORESOURCE_IO)) > > > + return -EINVAL; > > > + > > > + if (res->end > IO_SPACE_LIMIT) > > > + return -EINVAL; > > > + > > > + err = ioremap_page_range(res->start + (unsigned long)PCI_IOBASE, > > > + res->end + 1 + (unsigned long)PCI_IOBASE, > > > + phys_addr, __pgprot(PROT_DEVICE_nGnRE)); > > > > Except that PROT_DEVICE_nGnRE is arm64 only. I think that's a function > > that should remain arch specific. > > > > How about #defining a macro with the correct pgprot value in asm/pci.h > or asm/pgtable.h? > We can provide a default for that in another architecture independent > location. That should work. We already have pgprot_noncached/writecombine in asm-generic/pgtable.h which all architectures seem to include. The default can be pgprot_noncached and we would invoke it as pgprot_device(PAGE_KERNEL). -- Catalin -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html