On Sat, Jan 05, 2019 at 04:29:13PM +0100, Philipp K wrote:
> It is unusual to reference __cmpxchg() from other files than cmpxchg.h and
> similar.
> Instead, cmpxchg() is used, which expands to __cmpxchg() and derives the
> 'size' parameter automatically with sizeof(*(ptr)).
>
> So clean up the lock_cmos() function by using cmpxchg(), without changing
> the generated code.
>
> Signed-off-by: Philipp Klocke <[email protected]>
> ---
>
> This patch was acked by Ingo, so I would expect it to be added to pit.
You mean tip. :)
> arch/x86/include/asm/mc146818rtc.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/include/asm/mc146818rtc.h
> b/arch/x86/include/asm/mc146818rtc.h
> index 97198001e567..b72e3bbba0a2 100644
> --- a/arch/x86/include/asm/mc146818rtc.h
> +++ b/arch/x86/include/asm/mc146818rtc.h
> @@ -47,7 +47,7 @@ static inline void lock_cmos(unsigned char reg)
> cpu_relax();
> continue;
> }
> - if (__cmpxchg(&cmos_lock, 0, new, sizeof(cmos_lock)) == 0)
> + if (cmpxchg(&cmos_lock, 0, new) == 0)
> return;
> }
> }
> --
I don't know how you created this diff but yours breaks the indentation.
It should look like this:
--
diff --git a/arch/x86/include/asm/mc146818rtc.h
b/arch/x86/include/asm/mc146818rtc.h
index 97198001e567..b72e3bbba0a2 100644
--- a/arch/x86/include/asm/mc146818rtc.h
+++ b/arch/x86/include/asm/mc146818rtc.h
@@ -47,7 +47,7 @@ static inline void lock_cmos(unsigned char reg)
cpu_relax();
continue;
}
- if (__cmpxchg(&cmos_lock, 0, new, sizeof(cmos_lock)) == 0)
+ if (cmpxchg(&cmos_lock, 0, new) == 0)
return;
}
}
--
Also, you can simplify it even more by changing it to:
if (!cmpxchg(&cmos_lock, 0, new))
return;
Thx.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
