[PATCH V15 06/11] acpi: apei: handle SEA notification type for ARMv8

Borislav Petkov
2017-04-25T17:21:54Z

On Tue, Apr 18, 2017 at 05:05:18PM -0600, Tyler Baicar wrote:
> ARM APEI extension proposal added SEA (Synchronous External Abort)
> notification type for ARMv8.
> Add a new GHES error source handling function for SEA. If an error
> source's notification type is SEA, then this function can be registered
> into the SEA exception handler. That way GHES will parse and report
> SEA exceptions when they occur.
> An SEA can interrupt code that had interrupts masked and is treated as
> an NMI. To aid this the page of address space for mapping APEI buffers
> while in_nmi() is always reserved, and ghes_ioremap_pfn_nmi() is
> changed to use the helper methods to find the prot_t to map with in
> the same way as ghes_ioremap_pfn_irq().

...

> @@ -518,6 +520,17 @@ static int do_sea(unsigned long addr, unsigned int esr, struct pt_regs *regs)
> pr_err("Synchronous External Abort: %s (0x%08x) at 0x%016lx\n",
> inf->name, esr, addr);
>
> + /*
> + * Synchronous aborts may interrupt code which had interrupts masked.
> + * Before calling out into the wider kernel tell the interested
> + * subsystems.
> + */
> + if (IS_ENABLED(CONFIG_ACPI_APEI_SEA)) {
> + nmi_enter();
> + ghes_notify_sea();
> + nmi_exit();
> + }

Well, the other GHES notification methods use a notifier:
ghes_notify_sci, ghes_notify_nmi. You probably should do that too
instead of calling straight into a driver from arch code.

--
Regards/Gruss,
Boris.

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