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Commit 685659ee authored Jun 14, 2011 by yu liu Committed by Avi Kivity Jul 12, 2011

powerpc/e500: Save SPEFCSR in flush_spe_to_thread()



giveup_spe() saves the SPE state which is protected by MSR[SPE].
However, modifying SPEFSCR does not trap when MSR[SPE]=0.
And since SPEFSCR is already saved/restored in _switch(),
not all the callers want to save SPEFSCR again.
Thus, saving SPEFSCR should not belong to giveup_spe().

This patch moves SPEFSCR saving to flush_spe_to_thread(),
and cleans up the caller that needs to save SPEFSCR accordingly.

Signed-off-by: Liu Yu <yu.liu@freescale.com>
Acked-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>

parent a22a2dac

arch/powerpc/kernel/head_fsl_booke.S

+0 −2

Original line number	Original line	Diff line number	Diff line
	@@ -792,8 +792,6 @@ _GLOBAL(giveup_spe)
	evmwumiaa evr6, evr6, evr6 /* evr6 <- ACC = 0 * 0 + ACC */		evmwumiaa evr6, evr6, evr6 /* evr6 <- ACC = 0 * 0 + ACC */
	li r4,THREAD_ACC		li r4,THREAD_ACC
	evstddx evr6, r4, r3 /* save off accumulator */		evstddx evr6, r4, r3 /* save off accumulator */
	mfspr r6,SPRN_SPEFSCR
	stw r6,THREAD_SPEFSCR(r3) /* save spefscr register value */
	beq 1f		beq 1f
	lwz r4,_MSR-STACK_FRAME_OVERHEAD(r5)		lwz r4,_MSR-STACK_FRAME_OVERHEAD(r5)
	lis r3,MSR_SPE@h		lis r3,MSR_SPE@h

arch/powerpc/kernel/process.c

+1 −0

Original line number	Original line	Diff line number	Diff line
	@@ -213,6 +213,7 @@ void flush_spe_to_thread(struct task_struct *tsk)
	#ifdef CONFIG_SMP		#ifdef CONFIG_SMP
	BUG_ON(tsk != current);		BUG_ON(tsk != current);
	#endif		#endif
			tsk->thread.spefscr = mfspr(SPRN_SPEFSCR);
	giveup_spe(tsk);		giveup_spe(tsk);
	}		}
	preempt_enable();		preempt_enable();

arch/powerpc/kernel/traps.c

+1 −4

Original line number	Original line	Diff line number	Diff line
	@@ -1387,10 +1387,7 @@ void SPEFloatingPointException(struct pt_regs *regs)
	int code = 0;		int code = 0;
	int err;		int err;

	preempt_disable();		flush_spe_to_thread(current);
	if (regs->msr & MSR_SPE)
	giveup_spe(current);
	preempt_enable();

	spefscr = current->thread.spefscr;		spefscr = current->thread.spefscr;
	fpexc_mode = current->thread.fpexc_mode;		fpexc_mode = current->thread.fpexc_mode;