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Subject[PATCH 03/12] powerpc/8xx: Remove SoftwareEmulation()
Date
Since commit aa42c69c67f82 ("[POWERPC] Add support for FP emulation
for the e300c2 core"), program_check_exception() can be called for
math emulation. In that case, 'reason' is 0.

On the 8xx, there is a Software Emulation interrupt which is
called for all unimplemented and illegal instructions. This
interrupt calls SoftwareEmulation() which does almost the
same as program_check_exception() called with reason = 0.

The Software Emulation interrupt sets all reason bits to 0,
it is therefore possible to call program_check_exception()
directly from the interrupt handler.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
arch/powerpc/kernel/head_8xx.S | 2 +-
arch/powerpc/kernel/traps.c | 18 ------------------
2 files changed, 1 insertion(+), 19 deletions(-)

diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 07ddced6bab3..778a0e11d0e6 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -300,7 +300,7 @@ SystemCall:
/* On the MPC8xx, this is a software emulation interrupt. It occurs
* for all unimplemented and illegal instructions.
*/
- EXCEPTION(0x1000, SoftEmu, SoftwareEmulation, EXC_XFER_STD)
+ EXCEPTION(0x1000, SoftEmu, program_check_exception, EXC_XFER_STD)

. = 0x1100
/*
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index b328ca2aef9c..9d1f600bda08 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -1518,24 +1518,6 @@ void performance_monitor_exception(struct pt_regs *regs)
perf_irq(regs);
}

-#ifdef CONFIG_8xx
-void SoftwareEmulation(struct pt_regs *regs)
-{
- CHECK_FULL_REGS(regs);
-
- if (!user_mode(regs)) {
- debugger(regs);
- die("Kernel Mode Unimplemented Instruction or SW FPU Emulation",
- regs, SIGFPE);
- }
-
- if (!emulate_math(regs))
- return;
-
- _exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
-}
-#endif /* CONFIG_8xx */
-
#ifdef CONFIG_PPC_ADV_DEBUG_REGS
static void handle_debug(struct pt_regs *regs, unsigned long debug_status)
{
--
2.13.3
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