Subject: [PATCH] arm64: esr: Add ESR exception class encoding for trapped ERET

From: Will Deacon <[email-masked]>
Date: Tue, 30 Jul 2019 15:41:47 +0100

The ESR.EC encoding of 0b011010 (0x1a) describes an exception generated
by an ERET, ERETAA or ERETAB instruction as a result of a nested
virtualisation trap to EL2.

Add an encoding for this EC and a string description so that we identify
it correctly if we take one unexpectedly.

Signed-off-by: Will Deacon <[email-masked]>
---
 arch/arm64/include/asm/esr.h | 3 ++-
 arch/arm64/kernel/traps.c    | 1 +
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/esr.h b/arch/arm64/include/asm/esr.h
index 65ac18400979..cb29253ae86b 100644
--- a/arch/arm64/include/asm/esr.h
+++ b/arch/arm64/include/asm/esr.h
@@ -34,7 +34,8 @@
 #define ESR_ELx_EC_SMC64	(0x17)	/* EL2 and above */
 #define ESR_ELx_EC_SYS64	(0x18)
 #define ESR_ELx_EC_SVE		(0x19)
-/* Unallocated EC: 0x1A - 0x1E */
+#define ESR_ELx_EC_ERET		(0x1a)	/* EL2 only */
+/* Unallocated EC: 0x1b - 0x1E */
 #define ESR_ELx_EC_IMP_DEF	(0x1f)	/* EL3 only */
 #define ESR_ELx_EC_IABT_LOW	(0x20)
 #define ESR_ELx_EC_IABT_CUR	(0x21)
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index d3313797cca9..42c8422cdf4a 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -743,6 +743,7 @@ static const char *esr_class_str[] = {
 	[ESR_ELx_EC_SMC64]		= "SMC (AArch64)",
 	[ESR_ELx_EC_SYS64]		= "MSR/MRS (AArch64)",
 	[ESR_ELx_EC_SVE]		= "SVE",
+	[ESR_ELx_EC_ERET]		= "ERET/ERETAA/ERETAB",
 	[ESR_ELx_EC_IMP_DEF]		= "EL3 IMP DEF",
 	[ESR_ELx_EC_IABT_LOW]		= "IABT (lower EL)",
 	[ESR_ELx_EC_IABT_CUR]		= "IABT (current EL)",
-- 
2.11.0

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