diff options
| author | Vineet Gupta <vgupta@synopsys.com> | 2015-09-05 23:08:31 +0530 |
|---|---|---|
| committer | Vineet Gupta <vgupta@synopsys.com> | 2015-10-17 17:48:22 +0530 |
| commit | 55a2ae775ab4fe7aefa736e0fae6b8d4bd8aaab5 (patch) | |
| tree | 19e73c6b565f2ce0676a99f88e254411acf4a48a /arch/arc/include/asm/entry-compact.h | |
| parent | 9dbd3d9bfd56707f9b1ccc301506e2fac0e95795 (diff) | |
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 <vgupta@synopsys.com>
Diffstat (limited to 'arch/arc/include/asm/entry-compact.h')
| -rw-r--r-- | arch/arc/include/asm/entry-compact.h | 13 |
1 files changed, 6 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 |