Re: [PATCH 2/4] powerpc: mpc83xx: Allow including initreg.h into multiple files

["J. Neuschäfer" <j.ne@posteo.net>]

On Wed, Dec 18, 2024 at 02:18:48PM -0500, Sinan Akman wrote:
> Hi
> 
> On 2024-12-15 10:18, J. Neuschäfer via B4 Relay wrote:
> > From: "J. Neuschäfer"<j.ne@posteo.net>
> > 
> > Globals defined in headers can result in multiple-definition errors
> > while linking, if they are visible beyond the current translation unit.
> 
> Is this happening anywhere ? It seems you introduced this in your other
> patch :
> [PATCH 3/4] powerpc: mpc83xx: Use defined constant for SPCR[TBEN]

Right, I should have mentioned it: The problem appears only due to the
next patch.

> If this is the only place you are seeing the problem, can we not protect
> that the file is not included multiple times ?

The problem here is the inclusion of initreg.h into multiple .c files,
rather than multiple times into the same .c file. I don't think there's
an easy guard pattern against that (the proprocessor won't help here).

I think the benefit of being able to use these constants is big enough
to justify this change.


Thanks for your review,
 -- jn



> 
> > 
> > Signed-off-by: J. Neuschäfer<j.ne@posteo.net>
> > ---
> >   arch/powerpc/cpu/mpc83xx/initreg/initreg.h | 8 ++++----
> >   1 file changed, 4 insertions(+), 4 deletions(-)
> > 
> > diff --git a/arch/powerpc/cpu/mpc83xx/initreg/initreg.h b/arch/powerpc/cpu/mpc83xx/initreg/initreg.h
> > index 63aa5c946696ee0368bb3453b40ff0110f0fbcfd..ea1176e7fe10dbb549125ab6b2706fee05a92734 100644
> > --- a/arch/powerpc/cpu/mpc83xx/initreg/initreg.h
> > +++ b/arch/powerpc/cpu/mpc83xx/initreg/initreg.h
> > @@ -13,7 +13,7 @@
> >   #define SPCR_TSECBDP_MASK	0x00000C00
> >   #define SPCR_TSECEP_MASK	0x00000300
> > 
> > -	const __be32 spcr_mask =
> > +	static const __be32 spcr_mask =
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