From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3s9PNp2jPTzDr8c for ; Fri, 12 Aug 2016 09:29:14 +1000 (AEST) Received: from pps.filterd (m0098416.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.11/8.16.0.11) with SMTP id u7BNSZq7081048 for ; Thu, 11 Aug 2016 19:29:12 -0400 Received: from e23smtp02.au.ibm.com (e23smtp02.au.ibm.com [202.81.31.144]) by mx0b-001b2d01.pphosted.com with ESMTP id 24rqx1x78x-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Thu, 11 Aug 2016 19:29:07 -0400 Received: from localhost by e23smtp02.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 12 Aug 2016 09:29:04 +1000 Received: from d23relay10.au.ibm.com (d23relay10.au.ibm.com [9.190.26.77]) by d23dlp03.au.ibm.com (Postfix) with ESMTP id B000D3578056 for ; Fri, 12 Aug 2016 09:29:01 +1000 (EST) Received: from d23av02.au.ibm.com (d23av02.au.ibm.com [9.190.235.138]) by d23relay10.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u7BNT1tV32964692 for ; Fri, 12 Aug 2016 09:29:01 +1000 Received: from d23av02.au.ibm.com (localhost [127.0.0.1]) by d23av02.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u7BNT1hb003473 for ; Fri, 12 Aug 2016 09:29:01 +1000 From: Cyril Bur To: linuxppc-dev@lists.ozlabs.org, wei.guo.simon@gmail.com Cc: anton@samba.org, mikey@neuling.org Subject: [PATCH v2 04/20] powerpc: Return the new MSR from msr_check_and_set() Date: Fri, 12 Aug 2016 09:28:03 +1000 In-Reply-To: <20160811232819.11453-1-cyrilbur@gmail.com> References: <20160811232819.11453-1-cyrilbur@gmail.com> Message-Id: <20160811232819.11453-5-cyrilbur@gmail.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , mfmsr() is a fairly expensive call and callers of msr_check_and_set() may want to make decisions bits in the MSR that it did not change but may not know the value of. This patch would avoid a two calls to mfmsr(). Signed-off-by: Cyril Bur --- arch/powerpc/include/asm/reg.h | 2 +- arch/powerpc/kernel/process.c | 4 +++- 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h index f69f40f..0a3dde9 100644 --- a/arch/powerpc/include/asm/reg.h +++ b/arch/powerpc/include/asm/reg.h @@ -1247,7 +1247,7 @@ static inline void mtmsr_isync(unsigned long val) : "memory") #endif -extern void msr_check_and_set(unsigned long bits); +extern unsigned long msr_check_and_set(unsigned long bits); extern bool strict_msr_control; extern void __msr_check_and_clear(unsigned long bits); static inline void msr_check_and_clear(unsigned long bits) diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index 79f0615..216cf05 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -104,7 +104,7 @@ static int __init enable_strict_msr_control(char *str) } early_param("ppc_strict_facility_enable", enable_strict_msr_control); -void msr_check_and_set(unsigned long bits) +unsigned long msr_check_and_set(unsigned long bits) { unsigned long oldmsr = mfmsr(); unsigned long newmsr; @@ -118,6 +118,8 @@ void msr_check_and_set(unsigned long bits) if (oldmsr != newmsr) mtmsr_isync(newmsr); + + return newmsr; } void __msr_check_and_clear(unsigned long bits) -- 2.9.2