From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from VA3EHSOBE003.bigfish.com (va3ehsobe003.messaging.microsoft.com [216.32.180.13]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (Client CN "mail.global.frontbridge.com", Issuer "Cybertrust SureServer Standard Validation CA" (verified OK)) by ozlabs.org (Postfix) with ESMTPS id AE36CB6F7A for ; Tue, 29 Mar 2011 06:59:34 +1100 (EST) Date: Mon, 28 Mar 2011 14:59:23 -0500 From: Scott Wood To: Subject: [PATCH v2 1/4] powerpc/e500v2: Save SPEFCSR in flush_spe_to_thread() Message-ID: <20110328195923.GA25659@schlenkerla.am.freescale.net> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Cc: linuxppc-dev@lists.ozlabs.org, kvm-ppc@vger.kernel.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: yu liu 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 Signed-off-by: Scott Wood --- v2: added kvm-ppc (sorry for the resend) Kumar, could you ack this to go via the KVM tree, since the KVM SPE save/restore patches depend on it? arch/powerpc/kernel/head_fsl_booke.S | 2 -- arch/powerpc/kernel/process.c | 1 + arch/powerpc/kernel/traps.c | 5 +---- 3 files changed, 2 insertions(+), 6 deletions(-) diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S index 3e02710..b84fc5e 100644 --- a/arch/powerpc/kernel/head_fsl_booke.S +++ b/arch/powerpc/kernel/head_fsl_booke.S @@ -792,8 +792,6 @@ _GLOBAL(giveup_spe) evmwumiaa evr6, evr6, evr6 /* evr6 <- ACC = 0 * 0 + ACC */ li r4,THREAD_ACC evstddx evr6, r4, r3 /* save off accumulator */ - mfspr r6,SPRN_SPEFSCR - stw r6,THREAD_SPEFSCR(r3) /* save spefscr register value */ beq 1f lwz r4,_MSR-STACK_FRAME_OVERHEAD(r5) lis r3,MSR_SPE@h diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index f74f355..138e7dd 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -213,6 +213,7 @@ void flush_spe_to_thread(struct task_struct *tsk) #ifdef CONFIG_SMP BUG_ON(tsk != current); #endif + tsk->thread.spefscr = mfspr(SPRN_SPEFSCR); giveup_spe(tsk); } preempt_enable(); diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c index bd74fac..0ed23d1 100644 --- a/arch/powerpc/kernel/traps.c +++ b/arch/powerpc/kernel/traps.c @@ -1356,10 +1356,7 @@ void SPEFloatingPointException(struct pt_regs *regs) int code = 0; int err; - preempt_disable(); - if (regs->msr & MSR_SPE) - giveup_spe(current); - preempt_enable(); + flush_spe_to_thread(current); spefscr = current->thread.spefscr; fpexc_mode = current->thread.fpexc_mode; -- 1.7.1