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Commit fbbcc3bb authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

powerpc/8xx: Remove SoftwareEmulation() 



Since commit aa42c69c ("[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: default avatarChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent f70b1e8d

arch/powerpc/kernel/head_8xx.S

+1 −1
Original line number Diff line number Diff line
@@ -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

/*

arch/powerpc/kernel/traps.c

+0 −18
Original line number Diff line number Diff line
@@ -1522,24 +1522,6 @@ 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)

{