From 55a2ae775ab4fe7aefa736e0fae6b8d4bd8aaab5 Mon Sep 17 00:00:00 2001 From: Vineet Gupta Date: Sat, 5 Sep 2015 23:08:31 +0530 Subject: [PATCH] ARC: [arcompact] entry.S: Improve early return from exception The requirement is to - Reenable Exceptions (AE cleared) - Reenable Interrupts (E1/E2 set) We need to do wiggle these bits into ERSTATUS and call RTIE. Prev version used the pre-exception STATUS32 as starting point for what goes into ERSTATUS. This required explicit fixups of U/DE/L bits. Instead, use the current (in-exception) STATUS32 as starting point. Being in exception handler U/DE/L can be safely assumed to be correct. Only AE/E1/E2 need to be fixed. So the new implementation is slightly better -Avoids read form memory -Is 4 bytes smaller for the typical 1 level of intr configuration -Depicts the semantics more clearly Signed-off-by: Vineet Gupta --- arch/arc/include/asm/entry-compact.h | 13 ++++++------- arch/arc/include/asm/irqflags-compact.h | 2 ++ 2 files changed, 8 insertions(+), 7 deletions(-) diff --git a/arch/arc/include/asm/entry-compact.h b/arch/arc/include/asm/entry-compact.h index 415443c2a8c4..1aff3be91075 100644 --- a/arch/arc/include/asm/entry-compact.h +++ b/arch/arc/include/asm/entry-compact.h @@ -110,13 +110,12 @@ .macro FAKE_RET_FROM_EXCPN - ld r9, [sp, PT_status32] - bic r9, r9, (STATUS_U_MASK|STATUS_DE_MASK) - bset r9, r9, STATUS_L_BIT - sr r9, [erstatus] - mov r9, 55f - sr r9, [eret] - + lr r9, [status32] + bclr r9, r9, STATUS_AE_BIT + or r9, r9, (STATUS_E1_MASK|STATUS_E2_MASK) + sr r9, [erstatus] + mov r9, 55f + sr r9, [eret] rtie 55: .endm diff --git a/arch/arc/include/asm/irqflags-compact.h b/arch/arc/include/asm/irqflags-compact.h index a9490841c801..d8c608174617 100644 --- a/arch/arc/include/asm/irqflags-compact.h +++ b/arch/arc/include/asm/irqflags-compact.h @@ -23,11 +23,13 @@ #define STATUS_E2_BIT 2 /* Int 2 enable */ #define STATUS_A1_BIT 3 /* Int 1 active */ #define STATUS_A2_BIT 4 /* Int 2 active */ +#define STATUS_AE_BIT 5 /* Exception active */ #define STATUS_E1_MASK (1<