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From: Cyril Bur <cyrilbur@gmail.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: wei.guo.simon@gmail.com, mikey@neuling.org
Subject: [PATCH v4 04/20] powerpc: Return the new MSR from msr_check_and_set()
Date: Tue,  6 Sep 2016 09:44:32 +1000	[thread overview]
Message-ID: <20160905234448.5866-5-cyrilbur@gmail.com> (raw)
In-Reply-To: <20160905234448.5866-1-cyrilbur@gmail.com>

msr_check_and_set() always performs a mfmsr() to determine if it needs
to perform an mtmsr(), as mfmsr() can be a costly operation
msr_check_and_set() could return the MSR now on the CPU to avoid
callers of msr_check_and_set having to make their own mfmsr() call.

Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
---
 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 82308fd..c42581b 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -110,7 +110,7 @@ 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;
@@ -124,6 +124,8 @@ void msr_check_and_set(unsigned long bits)
 
 	if (oldmsr != newmsr)
 		mtmsr_isync(newmsr);
+
+	return newmsr;
 }
 
 void __msr_check_and_clear(unsigned long bits)
-- 
2.9.3

  parent reply	other threads:[~2016-09-05 23:45 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-09-05 23:44 [PATCH v4 00/20] Consistent TM structures Cyril Bur
2016-09-05 23:44 ` [PATCH v4 01/20] selftests/powerpc: Compile selftests against headers without AT_HWCAP2 Cyril Bur
2016-09-05 23:44 ` [PATCH v4 02/20] powerpc: Always restore FPU/VEC/VSX if hardware transactional memory in use Cyril Bur
2016-09-05 23:44 ` [PATCH v4 03/20] powerpc: Add check_if_tm_restore_required() to giveup_all() Cyril Bur
2016-09-05 23:44 ` Cyril Bur [this message]
2016-09-05 23:44 ` [PATCH v4 05/20] powerpc: Never giveup a reclaimed thread when enabling kernel {fp, altivec, vsx} Cyril Bur
2016-09-05 23:44 ` [PATCH v4 06/20] powerpc: signals: Stop using current in signal code Cyril Bur
2016-09-05 23:44 ` [PATCH v4 07/20] selftests/powerpc: Check for VSX preservation across userspace preemption Cyril Bur
2016-09-05 23:44 ` [PATCH v4 08/20] selftests/powerpc: Rework FPU stack placement macros and move to header file Cyril Bur
2016-09-05 23:44 ` [PATCH v4 09/20] selftests/powerpc: Move VMX stack frame macros " Cyril Bur
2016-09-05 23:44 ` [PATCH v4 10/20] selftests/powerpc: Introduce GPR asm helper " Cyril Bur
2016-09-05 23:44 ` [PATCH v4 11/20] selftests/powerpc: Allow tests to extend their kill timeout Cyril Bur
2016-09-05 23:44 ` [PATCH v4 12/20] selftests/powerpc: Add TM tcheck helpers in C Cyril Bur
2016-09-05 23:44 ` [PATCH v4 13/20] selftests/powerpc: Check that signals always get delivered Cyril Bur
2016-09-05 23:44 ` [PATCH v4 14/20] selftests/powerpc: Add checks for transactional GPRs in signal contexts Cyril Bur
2016-09-05 23:44 ` [PATCH v4 15/20] selftests/powerpc: Add checks for transactional FPUs " Cyril Bur
2016-09-05 23:44 ` [PATCH v4 16/20] selftests/powerpc: Add checks for transactional VMXs " Cyril Bur
2016-09-05 23:44 ` [PATCH v4 17/20] selftests/powerpc: Add checks for transactional VSXs " Cyril Bur
2016-09-05 23:44 ` [PATCH v4 18/20] powerpc: tm: Always use fp_state and vr_state to store live registers Cyril Bur
2016-09-05 23:44 ` [PATCH v4 19/20] powerpc: tm: Rename transct_(*) to ck(\1)_state Cyril Bur
2016-09-05 23:44 ` [PATCH v4 20/20] powerpc: Remove do_load_up_transact_{fpu,altivec} Cyril Bur

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