Re: [PATCH -next] powerpc: kernel/time.c - cleanup warnings

[heying (H)]

在 2021/3/17 19:16, Christophe Leroy 写道:
> Le 17/03/2021 à 11:34, He Ying a écrit :
> > We found these warnings in arch/powerpc/kernel/time.c as follows:
> > warning: symbol 'decrementer_max' was not declared. Should it be static?
> > warning: symbol 'rtc_lock' was not declared. Should it be static?
> > warning: symbol 'dtl_consumer' was not declared. Should it be static?
> >
> > Declare 'decrementer_max' in arch/powerpc/include/asm/time.h. And 
> > include
> > proper header in which 'rtc_lock' is declared. Move 'dtl_consumer'
> > definition behind "include <asm/dtl.h>" because 'dtl_consumer' is 
> > declared
> > there.
> >
> > Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
> > Signed-off-by: He Ying <heying24@xxxxxxxxxx>
> > ---
> >   arch/powerpc/include/asm/time.h | 1 +
> >   arch/powerpc/kernel/time.c      | 7 +++----
> >   2 files changed, 4 insertions(+), 4 deletions(-)
> >
> > diff --git a/arch/powerpc/include/asm/time.h 
> > b/arch/powerpc/include/asm/time.h
> > index 8dd3cdb25338..2cd2b50bedda 100644
> > --- a/arch/powerpc/include/asm/time.h
> > +++ b/arch/powerpc/include/asm/time.h
> > @@ -22,6 +22,7 @@ extern unsigned long tb_ticks_per_jiffy;
> >   extern unsigned long tb_ticks_per_usec;
> >   extern unsigned long tb_ticks_per_sec;
> >   extern struct clock_event_device decrementer_clockevent;
> > +extern u64 decrementer_max;
> >       extern void generic_calibrate_decr(void);
> > diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
> > index b67d93a609a2..409967713ca6 100644
> > --- a/arch/powerpc/kernel/time.c
> > +++ b/arch/powerpc/kernel/time.c
> > @@ -55,6 +55,7 @@
> >   #include <linux/sched/cputime.h>
> >   #include <linux/sched/clock.h>
> >   #include <linux/processor.h>
> > +#include <linux/mc146818rtc.h>
>
> I don't think that's the good place. It has no link to powerpc, it is 
> only by chance that it has the same name.
>
> As rtc_lock is defined in powerpc time.c, I think you should declare 
> it in powerpc asm/time.h

My first thought was the same as yours. I tried to add declaration in 
powerpc asm/time.h, but got a compiling error:

drivers/rtc/rtc-vr41xx.c:75:24: error: static declaration of ‘rtc_lock’ 
follows non-static declaration
 static DEFINE_SPINLOCK(rtc_lock);

In file included from ./arch/powerpc/include/asm/delay.h:7:0,
                 from ./arch/powerpc/include/asm/io.h:33,
                 from ./include/linux/io.h:13,
                 from drivers/rtc/rtc-vr41xx.c:11:
./arch/powerpc/include/asm/time.h:25:19: note: previous declaration of 
‘rtc_lock’ was here
 extern spinlock_t rtc_lock;

There's a conflict. Perhaps I can rename it in drivers/rtc/rtc-vr41xx.c.


But I find an existing declaration in linux/mc146818rtc.h and there's 
only one definition for 'rtc_lock' in powerpc.

There's some includes of mc146818rtc.h in powperc. I wonder they point 
to the same thing. But I'm not very sure

because the header's name looks a bit strange.

> >   #include <asm/trace.h>
> >     #include <asm/interrupt.h>
> > @@ -150,10 +151,6 @@ bool tb_invalid;
> >   u64 __cputime_usec_factor;
> >   EXPORT_SYMBOL(__cputime_usec_factor);
> >   -#ifdef CONFIG_PPC_SPLPAR
> > -void (*dtl_consumer)(struct dtl_entry *, u64);
> > -#endif
> > -
> >   static void calc_cputime_factors(void)
> >   {
> >       struct div_result res;
> > @@ -179,6 +176,8 @@ static inline unsigned long read_spurr(unsigned 
> > long tb)
> >     #include <asm/dtl.h>
> >   +void (*dtl_consumer)(struct dtl_entry *, u64);
> > +
> >   /*
> >    * Scan the dispatch trace log and count up the stolen time.
> >    * Should be called with interrupts disabled.
> .