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authorJames Morse <james.morse@arm.com>2018-01-15 22:38:59 +0300
committerCatalin Marinas <catalin.marinas@arm.com>2018-01-16 18:07:12 +0300
commit68ddbf09ec5a888ec850edd7e7438d2daf069c56 (patch)
tree07f56625a64473270c90dcfc8c74589540b81e96 /arch/arm64/include/asm/exception.h
parentf751daa4f9d3da07e2777ea0c1ba2d58ff2c860f (diff)
downloadlinux-68ddbf09ec5a888ec850edd7e7438d2daf069c56.tar.xz
arm64: kernel: Prepare for a DISR user
KVM would like to consume any pending SError (or RAS error) after guest exit. Today it has to unmask SError and use dsb+isb to synchronise the CPU. With the RAS extensions we can use ESB to synchronise any pending SError. Add the necessary macros to allow DISR to be read and converted to an ESR. We clear the DISR register when we enable the RAS cpufeature, and the kernel has not executed any ESB instructions. Any value we find in DISR must have belonged to firmware. Executing an ESB instruction is the only way to update DISR, so we can expect firmware to have handled any deferred SError. By the same logic we clear DISR in the idle path. Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/include/asm/exception.h')
-rw-r--r--arch/arm64/include/asm/exception.h14
1 files changed, 14 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/exception.h b/arch/arm64/include/asm/exception.h
index 0c2eec490abf..bc30429d8e91 100644
--- a/arch/arm64/include/asm/exception.h
+++ b/arch/arm64/include/asm/exception.h
@@ -18,6 +18,8 @@
#ifndef __ASM_EXCEPTION_H
#define __ASM_EXCEPTION_H
+#include <asm/esr.h>
+
#include <linux/interrupt.h>
#define __exception __attribute__((section(".exception.text")))
@@ -27,4 +29,16 @@
#define __exception_irq_entry __exception
#endif
+static inline u32 disr_to_esr(u64 disr)
+{
+ unsigned int esr = ESR_ELx_EC_SERROR << ESR_ELx_EC_SHIFT;
+
+ if ((disr & DISR_EL1_IDS) == 0)
+ esr |= (disr & DISR_EL1_ESR_MASK);
+ else
+ esr |= (disr & ESR_ELx_ISS_MASK);
+
+ return esr;
+}
+
#endif /* __ASM_EXCEPTION_H */