Messages in this thread Patch in this message | | | From | Vineet Gupta <> | Subject | [PATCH 17/20] ARC: entry: replace 8 byte OR with 4 byte BSET | Date | Mon, 14 Aug 2023 17:48:10 -0700 |
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FAKE_RET_FROM_EXCEPTION drops down to pure kernel mode. It currently has an 8 byte instruction which can be replaced with 4 byte BSET
This is applicable to both ARCv2 and ARCv3 entr code.
ARCv2 current ------------ 00000804 <EV_Trap>: ... 874: 216a 1280 lr r9,[status32] 878: 2146 1809 bic r9,r9,0x20 87c: 2105 1f89 8000 0000 or r9,r9,0x80000000 ^^^^^^^^^ 884: 2029 8240 kflag r9
ARCv2 after ---------- 000007e0 <EV_Trap>: ... 850: 216a 1280 lr r9,[status32] 854: 2150 1149 bclr r9,r9,0x5 858: 214f 17c9 bset r9,r9,0x1f 85c: 2029 8240 kflag r9
Signed-off-by: Vineet Gupta <vgupta@kernel.org> --- arch/arc/include/asm/entry-arcv2.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/arc/include/asm/entry-arcv2.h b/arch/arc/include/asm/entry-arcv2.h index 11b48ab39154..f7c9b3915d10 100644 --- a/arch/arc/include/asm/entry-arcv2.h +++ b/arch/arc/include/asm/entry-arcv2.h @@ -274,8 +274,8 @@ .macro FAKE_RET_FROM_EXCPN lr r9, [status32] - bic r9, r9, STATUS_AE_MASK - or r9, r9, STATUS_IE_MASK + bclr r9, r9, STATUS_AE_BIT + bset r9, r9, STATUS_IE_BIT kflag r9 .endm -- 2.34.1
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