From: Cyril Bur <cyrilbur@gmail.com>
To: linuxppc-dev@lists.ozlabs.org, wei.guo.simon@gmail.com
Cc: mikey@neuling.org, anton@samba.org
Subject: [PATCH v3 04/21] powerpc: Return the new MSR from msr_check_and_set()
Date: Wed, 17 Aug 2016 13:43:06 +1000 [thread overview]
Message-ID: <20160817034323.23053-5-cyrilbur@gmail.com> (raw)
In-Reply-To: <20160817034323.23053-1-cyrilbur@gmail.com>
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 <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
next prev parent reply other threads:[~2016-08-17 3:44 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-17 3:43 [PATCH v3 00/21] Consistent TM structures Cyril Bur
2016-08-17 3:43 ` [PATCH v3 01/21] selftests/powerpc: Compile selftests against headers without AT_HWCAP2 Cyril Bur
2016-08-17 3:43 ` [PATCH v3 02/21] powerpc: Always restore FPU/VEC/VSX if hardware transactional memory in use Cyril Bur
2016-08-19 6:33 ` Michael Neuling
2016-08-23 0:57 ` Cyril Bur
2016-08-17 3:43 ` [PATCH v3 03/21] powerpc: Add check_if_tm_restore_required() to giveup_all() Cyril Bur
2016-08-19 6:40 ` Michael Neuling
2016-08-17 3:43 ` Cyril Bur [this message]
2016-08-17 3:53 ` [PATCH v3 04/21] powerpc: Return the new MSR from msr_check_and_set() Cyril Bur
2016-08-19 6:47 ` Michael Neuling
2016-08-17 3:43 ` [PATCH v3 05/21] powerpc: Never giveup a reclaimed thread when enabling kernel {fp, altivec, vsx} Cyril Bur
2016-08-17 3:43 ` [PATCH v3 06/21] powerpc: signals: Stop using current in signal code Cyril Bur
2016-08-17 4:31 ` kbuild test robot
2016-08-17 3:43 ` [PATCH v3 07/21] selftests/powerpc: Check for VSX preservation across userspace preemption Cyril Bur
2016-08-17 3:43 ` [PATCH v3 08/21] selftests/powerpc: Rework FPU stack placement macros and move to header file Cyril Bur
2016-08-17 3:43 ` [PATCH v3 09/21] selftests/powerpc: Move VMX stack frame macros " Cyril Bur
2016-08-17 3:43 ` [PATCH v3 10/21] selftests/powerpc: Introduce GPR asm helper " Cyril Bur
2016-08-17 3:43 ` [PATCH v3 11/21] selftests/powerpc: Add transactional memory defines Cyril Bur
2016-08-17 3:43 ` [PATCH v3 12/21] selftests/powerpc: Allow tests to extend their kill timeout Cyril Bur
2016-08-17 3:43 ` [PATCH v3 13/21] selftests/powerpc: Add TM tcheck helpers in C Cyril Bur
2016-08-17 3:43 ` [PATCH v3 14/21] selftests/powerpc: Check that signals always get delivered Cyril Bur
2016-08-17 3:43 ` [PATCH v3 15/21] selftests/powerpc: Add checks for transactional GPRs in signal contexts Cyril Bur
2016-08-17 3:43 ` [PATCH v3 16/21] selftests/powerpc: Add checks for transactional FPUs " Cyril Bur
2016-08-17 3:43 ` [PATCH v3 17/21] selftests/powerpc: Add checks for transactional VMXs " Cyril Bur
2016-08-17 3:43 ` [PATCH v3 18/21] selftests/powerpc: Add checks for transactional VSXs " Cyril Bur
2016-08-17 3:43 ` [PATCH v3 19/21] powerpc: tm: Always use fp_state and vr_state to store live registers Cyril Bur
2016-08-19 4:04 ` Simon Guo
2016-08-17 3:43 ` [PATCH v3 20/21] powerpc: tm: Rename transct_(*) to ck(\1)_state Cyril Bur
2016-08-17 3:43 ` [PATCH v3 21/21] powerpc: Remove do_load_up_transact_{fpu,altivec} Cyril Bur
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