Messages in this thread | | | Date | Thu, 16 Mar 2017 23:05:19 +0100 | From | "Luis R. Rodriguez" <> | Subject | Re: [PATCH v1] x86/mm, asm-generic: Add IOMMU ioremap_uc() variant default |
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On Thu, Mar 16, 2017 at 03:46:51PM -0500, Bjorn Helgaas wrote: > On Thu, Jul 9, 2015 at 7:28 PM, Luis R. Rodriguez > <mcgrof@do-not-panic.com> wrote: > > > +/** > > + * DOC: ioremap() and ioremap_*() variants > > + * > > + * If you have an IOMMU your architecture is expected to have both ioremap() > > + * and iounmap() implemented otherwise the asm-generic helpers will provide a > > + * direct mapping. > > + * > > + * There are ioremap_*() call variants, if you have no IOMMU we naturally will > > + * default to direct mapping for all of them, you can override these defaults. > > + * If you have an IOMMU you are highly encouraged to provide your own > > + * ioremap variant implementation as there currently is no safe architecture > > + * agnostic default. To avoid possible improper behaviour default asm-generic > > + * ioremap_*() variants all return NULL when an IOMMU is available. If you've > > + * defined your own ioremap_*() variant you must then declare your own > > + * ioremap_*() variant as defined to itself to avoid the default NULL return. > > Are the references above to "IOMMU" typos? Should they say "MMU" > instead, so they match the #ifdef below?
Yes. Patch welcomed.
Luis
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