Messages in this thread | | | Date | Sat, 29 Aug 2015 08:25:05 -0700 | From | Christoph Hellwig <> | Subject | Re: [RFC] asm-generic/pci_iomap.h: make custom PCI BAR requirements explicit |
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On Fri, Aug 28, 2015 at 05:17:27PM -0700, Luis R. Rodriguez wrote: > From: "Luis R. Rodriguez" <mcgrof@suse.com> > > The S390 architecture requires a custom pci_iomap() implementation > as the asm-generic implementation assumes there are disjunctions > between PCI BARs, and on S390 PCI BAR are not disjunctive, S390 requires > the bar parameter in order to find the corresponding device and create > the mapping cookie. > > This clash with the asm-generic pci_iomap() implementation is implicit, > there are no current semantics to make this incompatability explicit. > Make the S390 PCI BAR non-disjunction incompatibility explicit, and > also pave the way for alternative incompatibilities to be defined. > > While at it, as with the ioremap*() variants, since we have no clear > semantics yet well defined provide a solution for them that returns > NULL. This allows architectures to move forward by defining pci_ioremap*() > variants without requiring immediate changes to all architectures. Each > architecture then can implement their own solution as needed and > when they get to it.
Now that you have the config symbol available why not move the S390 implementation to generic code based on that can kill of asm/pci_iomap.h? Seems like we're really not dealing with something inherent to the architecture, but two possible implementations based on architecture constraints.
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