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

From: Will Deacon
Date: Thu Nov 02 2017 - 06:19:35 EST


On Tue, Oct 31, 2017 at 03:38:26PM +0000, 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.
>
> Thanks,
>
> James Morse (6):
> arm64: fixmap: Add GHES fixmap entries
> x86/mm/fixmap: Add GHES fixmap entries
> ACPI / APEI: Replace ioremap_page_range() with fixmap
> ACPI / APEI: Remove ghes_ioremap_area
> arm64: mm: Remove arch_apei_flush_tlb_one()
> ACPI / APEI: Remove arch_apei_flush_tlb_one()
>
> arch/arm64/include/asm/acpi.h | 12 ------
> arch/arm64/include/asm/fixmap.h | 5 +++
> arch/arm64/mm/mmu.c | 4 ++

If you need it:

Acked-by: Will Deacon <will.deacon@xxxxxxx>

for the arm64 bits.

Will