On Fri, Jul 23, 2010 at 09:14:50PM -0300, Henrique de Moraes Holschuh wrote:
quoted text
> Well, as it was raised in this thread, ACPI tables are likely to be near RAM
> regions used for IPC with the firmware or SMBIOS, and we have no idea of the
> kind of crap that could happen if we enable caching on those areas.
> 
> OTOH, we *know* of systems that force us to copy the ACPI tables to regular
> RAM, otherwise, the utterly broken BIOS corrupts the ACPI tables after the
> kernel has loaded.
>
> Couldn't we simply always copy all tables to regular RAM and mark THAT as
> cacheable (since there will be no IPC regions in it)?  For the tables that
> are only used once, we can free the RAM later.

I think this is reasonable. There's an argument that we shouldn't cache 
operation regions that may be sitting next to the ACPI tables, but I 
can't see any problems being caused by copying the tables to RAM.

-- 
Matthew Garrett | mjg59@srcf.ucam.org
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