Hi Tyler,
On 06/03/17 20:44, 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().
> diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
> index d178dc0..b2d57fc 100644
> --- a/arch/arm64/mm/fault.c
> +++ b/arch/arm64/mm/fault.c
> @@ -41,6 +41,8 @@
> #include <asm/pgtable.h>
> #include <asm/tlbflush.h>
>
> +#include <acpi/ghes.h>
> +
> static const char *fault_name(unsigned int esr);
>
> #ifdef CONFIG_KPROBES
> @@ -498,6 +500,17 @@ 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",
> fault_name(esr), 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(ACPI_APEI_SEA)) {
IS_ENABLED() needs the CONFIG_ version of the symbols, otherwise this doesn't
get built.
(I guess the testing from the previous always-enabled version is still valid)
> + nmi_enter();
> + ghes_notify_sea();
> + nmi_exit();
> + }
> +
> info.si_signo = SIGBUS;
> info.si_errno = 0;
> info.si_code = 0;
> diff --git a/drivers/acpi/apei/Kconfig b/drivers/acpi/apei/Kconfig
> index b0140c8..c545dd1 100644
> --- a/drivers/acpi/apei/Kconfig
> +++ b/drivers/acpi/apei/Kconfig
> @@ -39,6 +39,21 @@ config ACPI_APEI_PCIEAER
> PCIe AER errors may be reported via APEI firmware first mode.
> Turn on this option to enable the corresponding support.
>
> +config ACPI_APEI_SEA
> + bool "APEI Synchronous External Abort logging/recovering support"
> + depends on ARM64 && ACPI_APEI && ACPI_APEI_GHES
Nit: ACPI_APEI_GHES already depends on ACPI_APEI
> + default y
> + help
> + This option should be enabled if the system supports
> + firmware first handling of SEA (Synchronous External Abort).
> + SEA happens with certain faults of data abort or instruction
> + abort synchronous exceptions on ARMv8 systems. If a system
> + supports firmware first handling of SEA, the platform analyzes
> + and handles hardware error notifications from SEA, and it may then
> + form a HW error record for the OS to parse and handle. This
> + option allows the OS to look for such hardware error record, and
> + take appropriate action.
> +
> config ACPI_APEI_MEMORY_FAILURE
> bool "APEI memory error recovering support"
> depends on ACPI_APEI && MEMORY_FAILURE
Reviewed-by: James Morse <james.morse@xxxxxxx>
Thanks,
James
