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authorJames Morse <james.morse@arm.com>2019-01-29 18:48:50 +0000
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2019-02-07 23:10:45 +0100
commitd44f1b8dd7e66d80cc4205809e5ace866bd851da (patch)
tree102c993327b0f620c9d1aefcc95ad3d7819fd68c /arch/arm64/include/asm/acpi.h
parent0db5e0223035b2c84e6186831fc27511270af812 (diff)
downloadlinux-d44f1b8dd7e66d80cc4205809e5ace866bd851da.tar.gz
arm64: KVM/mm: Move SEA handling behind a single 'claim' interface
To split up APEIs in_nmi() path, the caller needs to always be
in_nmi(). Add a helper to do the work and claim the notification.

When KVM or the arch code takes an exception that might be a RAS
notification, it asks the APEI firmware-first code whether it wants
to claim the exception. A future kernel-first mechanism may be queried
afterwards, and claim the notification, otherwise we fall through
to the existing default behaviour.

The NOTIFY_SEA code was merged before considering multiple, possibly
interacting, NMI-like notifications and the need to consider kernel
first in the future. Make the 'claiming' behaviour explicit.

Restructuring the APEI code to allow multiple NMI-like notifications
means any notification that might interrupt interrupts-masked
code must always be wrapped in nmi_enter()/nmi_exit(). This will
allow APEI to use in_nmi() to use the right fixmap entries.

Mask SError over this window to prevent an asynchronous RAS error
arriving and tripping 'nmi_enter()'s BUG_ON(in_nmi()).

Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Tested-by: Tyler Baicar <tbaicar@codeaurora.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'arch/arm64/include/asm/acpi.h')
-rw-r--r--arch/arm64/include/asm/acpi.h4
1 files changed, 3 insertions, 1 deletions
diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
index 2def77ec14be..7628efbe6c12 100644
--- a/arch/arm64/include/asm/acpi.h
+++ b/arch/arm64/include/asm/acpi.h
@@ -18,6 +18,7 @@
 
 #include <asm/cputype.h>
 #include <asm/io.h>
+#include <asm/ptrace.h>
 #include <asm/smp_plat.h>
 #include <asm/tlbflush.h>
 
@@ -110,9 +111,10 @@ static inline u32 get_acpi_id_for_cpu(unsigned int cpu)
 
 static inline void arch_fix_phys_package_id(int num, u32 slot) { }
 void __init acpi_init_cpus(void);
-
+int apei_claim_sea(struct pt_regs *regs);
 #else
 static inline void acpi_init_cpus(void) { }
+static inline int apei_claim_sea(struct pt_regs *regs) { return -ENOENT; }
 #endif /* CONFIG_ACPI */
 
 #ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL