[Ksummit-discuss] [TECH TOPIC] Semantics of MMIO mapping attributes accross archs

[Luck, Tony]

>> Another side topic that has come up in this space is the desire to
>> define a "memremap" api to clean up __iomem abuses for cases where
>> "memory-like" mappings are needed.
>>
>> https://lkml.org/lkml/2015/6/22/100
>
> Interesting. I had missed this. There is a similar question about
> semantics (ordering etc...), ie, are they the same as memory for
> example ?

The drivers/acpi/apei/* usages are just mapping bits of normal memory that
happens to be BIOS reserved.  ioremap*() got used because it was available
and did the right thing with the page tables even though it broke the __iomem
annotations.  memremap() sounds like a great idea for these.

-Tony