Messages in this thread | | | Subject | Re: [RFC PATCH] PCI: remove access to pci_[enable|disable]_msi() for drivers - take 2 | From | Roland Dreier <> | Date | Wed, 08 Jun 2005 08:47:38 -0700 |
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Greg> I've also seen some complaints that it is very arch specific Greg> (x86 based). But as no other arches seem to want to support Greg> MSI, I don't really see any need to split it up. Any Greg> comments about this?
Grant> IA64 supports MSI/MSI-X. Roland, didn't PPC as well?
Grant> I don't think it's *that* x86 specific. The base address Grant> of the Processor interrupt Block (IIRC 0xfee0000) is Grant> implemented the same on several arches AFAIK. Even on some Grant> parisc chipsets. I been constantly chasing other basic Grant> issues on parisc and just haven't had time to implement it Grant> in the past 3 years.
Some PPC does support MSI. For example the PCI-X host bridge inside the IBM (now AMCC) PPC 440GP supports MSI. I don't know if any non-embedded PPC or PPC64 supports MSI though -- for example do any IBM POWER-based systems support MSI??
The current code isn't exactly x86-specific. It's more Intel APIC specific, which means that chipsets that for some reason or another support the same address/message format will work. So ia64 works as well. Following from that, HP parisc boxes that use the same chipset as HP ia64 boxes have a chance at working.
But the PPC 440GP uses a different address and a different message format. So if anyone cared about supporting that, the current code would have to be made more generic.
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