p71924506
/
linux_old1
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

powerpc: Return the new MSR from msr_check_and_set() 

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>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Cyril Bur 2016-09-23 16:18:10 +10:00 committed by Michael Ellerman
parent b0f16b4698
commit 3cee070a13
2 changed files with 4 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/powerpc/include/asm/reg.h
View File

@ -1250,7 +1250,7 @@ static inline void mtmsr_isync(unsigned long val)
: "memory") : "memory")
#endif #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 bool strict_msr_control;
extern void __msr_check_and_clear(unsigned long bits); extern void __msr_check_and_clear(unsigned long bits);
static inline void msr_check_and_clear(unsigned long bits) static inline void msr_check_and_clear(unsigned long bits)

4
arch/powerpc/kernel/process.c
View File

@ -111,7 +111,7 @@ static int __init enable_strict_msr_control(char *str)
} }
early_param("ppc_strict_facility_enable", enable_strict_msr_control); 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 oldmsr = mfmsr();
unsigned long newmsr; unsigned long newmsr;
@ -125,6 +125,8 @@ void msr_check_and_set(unsigned long bits)
if (oldmsr != newmsr) if (oldmsr != newmsr)
mtmsr_isync(newmsr); mtmsr_isync(newmsr);
return newmsr;
} }
void __msr_check_and_clear(unsigned long bits) void __msr_check_and_clear(unsigned long bits)