Re: [RFC/RFT PATCH 0/6] Switch GHES ioremap_page_range() to use fixmap

From: Tyler Baicar
Date: Tue Oct 31 2017 - 14:46:45 EST


On 10/31/2017 11:38 AM, James Morse wrote:
GHES is doing ioremap_page_range() in both NMI and irq context, neither
are safe as it may sleep to allocate intermediate levels of page table.

Replace the NMI/irq GHES_IOREMAP_PAGES to use a fixmap entry each.

After this nothing uses ghes_ioremap_area or arch_apei_flush_tlb_one(),
rip them out.

RFC as I've only build-tested this on x86. For arm64 I've tested it on a
software model. Any more testing would be welcome. These patches are based
on rc7.
For the arm64 and APEI patches:
Tested-by: Tyler Baicar <tbaicar@xxxxxxxxxxxxxx>

Verified on arm64. I no longer see the BUGs in the GHES code. Thanks!

Tyler

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