Messages in this thread | | | Date | Fri, 6 May 2022 14:16:56 +0100 (BST) | From | "Maciej W. Rozycki" <> | Subject | Re: [RFC v2 01/39] Kconfig: introduce HAS_IOPORT option and select it as necessary |
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On Fri, 6 May 2022, Arnd Bergmann wrote:
> > So what happens if the instruction is given an I/O rather than memory BAR > > as the relevant argument? Is the address space indicator bit (bit #0) > > simply ignored or what? > > Not sure. My best guess is that it would actually work as you'd expect, > but is deliberately left out of the architecture specification so they don't > have to to validate the correctness. Note that only a small number of > PCIe cards are actually supported by IBM, and I think the firmware > only passes devices to the OS if they are whitelisted.
That makes sense, thanks!
Maciej
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