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Subject[PATCH] powerpc/8xx: Fix software emulation interrupt
Date
For unimplemented instructions or unimplemented SPRs, the 8xx triggers
a "Software Emulation Exception" (0x1000). That interrupt doesn't set
reason bits in SRR1 as the "Program Check Exception" does.

Go through emulation_assist_interrupt() to set REASON_ILLEGAL.

Fixes: fbbcc3bb139e ("powerpc/8xx: Remove SoftwareEmulation()")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
I'm wondering whether it wouldn't be better to set REASON_ILLEGAL
in the exception prolog and still call program_check_exception.
And do the same in book3s/64 to avoid the nightmare of an
INTERRUPT_HANDLER calling another INTERRUPT_HANDLER.
---
arch/powerpc/kernel/head_8xx.S | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 52702f3db6df..9eb63cf6ac38 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -165,7 +165,7 @@ SystemCall:
/* On the MPC8xx, this is a software emulation interrupt. It occurs
* for all unimplemented and illegal instructions.
*/
- EXCEPTION(0x1000, SoftEmu, program_check_exception, EXC_XFER_STD)
+ EXCEPTION(0x1000, SoftEmu, emulation_assist_interrupt, EXC_XFER_STD)

. = 0x1100
/*
--
2.25.0
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