Messages in this thread | | | Date | Thu, 27 May 2010 15:41:44 +0200 | Subject | Re: [PATCH] arch/tile: new multi-core architecture for Linux | From | Geert Uytterhoeven <> |
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On Thu, May 27, 2010 at 15:30, Chris Metcalf <cmetcalf@tilera.com> wrote: > On 5/27/2010 4:41 AM, Arnd Bergmann wrote: >> On Thursday 27 May 2010, Chris Metcalf wrote: >>>> +EXPORT_SYMBOL(inb); >>>> >>>> If you just remove these definitions, you get a link error for any >>>> driver that tries to use these, which is probably more helpful than >>>> the panic. >>>> >>>> OTOH, are you sure that you can't just map the PIO calls to mmio functions >>>> like readb plus some fixed offset? On most non-x86 architectures, the PIO >>>> area of the PCI bus is just mapped to a memory range somewhere. >>>> >>>> >>> I'll try to remove them and see if anything falls over. We don't have >>> any memory-mapped addresses in the 32-bit architecture, though that >>> changes with the 64-bit architecture, which introduces IO mappings. For >>> PCI we actually have to do a hypervisor transaction for reads or writes. >>> >> Ok, then I assume that PIO would also be a hypervisor call, right? >> If you don't have MMIO on 32 bit, you might want to not define either >> PIO (inb, ...) no MMIO (readb, ...) calls there and disable >> CONFIG_HAVE_MMIO in Kconfig. >> > > We don't define CONFIG_HAVE_MMIO, but drivers certainly seem to use > ioread/iowrite methods as well as inb/outb without guarding them with > any particular tests, so we have to provide definitions of some kind for > all of them. I'll confer with our PCI developer to see if we can clean > up the set of definitions in io.h.
It's CONFIG_NO_IOMEM (cfr. s390 and um), which is inverted and turned into CONFIG_HAS_IOMEM, to be checked by drivers.
Gr{oetje,eeting}s,
Geert
-- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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