Re: [PATCH 2/2] edac: cpc925: Use of_get_cpu_hwid() to read CPU node 'reg'

[Rob Herring <robh@kernel.org>]

On Tue, Apr 18, 2023 at 07:50:00PM +0200, Borislav Petkov wrote:
> On Sun, Mar 19, 2023 at 10:01:41AM -0500, Rob Herring wrote:
> > Replace open coded reading of CPU nodes' "reg" properties with
> > of_get_cpu_hwid() dedicated for this purpose.
> > 
> > Signed-off-by: Rob Herring <robh@kernel.org>
> > ---
> >  drivers/edac/cpc925_edac.c | 6 +++---
> >  1 file changed, 3 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/edac/cpc925_edac.c b/drivers/edac/cpc925_edac.c
> > index ee193aae8e14..0182436c1b5a 100644
> > --- a/drivers/edac/cpc925_edac.c
> > +++ b/drivers/edac/cpc925_edac.c
> > @@ -557,13 +557,13 @@ static u32 cpc925_cpu_mask_disabled(void)
> >  	mask = APIMASK_ADI0 | APIMASK_ADI1;
> >  
> >  	for_each_of_cpu_node(cpunode) {
> > -		const u32 *reg = of_get_property(cpunode, "reg", NULL);
> > -		if (reg == NULL || *reg > 2) {
> > +		int hwid = of_get_cpu_hwid(cpunode, 0);
> > +		if ((hwid < 0) || (hwid > 2)) {
> >  			cpc925_printk(KERN_ERR, "Bad reg value at %pOF\n", cpunode);
> >  			continue;
> >  		}
> >  
> > -		mask &= ~APIMASK_ADI(*reg);
> > +		mask &= ~APIMASK_ADI(hwid);
> >  	}
> >  
> >  	if (mask != (APIMASK_ADI0 | APIMASK_ADI1)) {
> > -- 
> 
> $ grep CPC925 .config
> CONFIG_EDAC_CPC925=m
> 
> $ make ARCH=powerpc CROSS_COMPILE=/home/boris/src/crosstool/gcc-11.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-
> ...
> ERROR: modpost: ".of_get_cpu_hwid" [drivers/edac/cpc925_edac.ko] undefined!
> make[1]: *** [scripts/Makefile.modpost:136: Module.symvers] Error 1
> make: *** [Makefile:1980: modpost] Error 2

I'd rather not export of_get_cpu_hwid() which is otherwise only used in 
arch code. I think I'll rewrite this in terms of for_each_possible_cpu() 
and topology_core_id(). Though that would make a UP build not enable 
core 1, but that seems undesirable anyways. 

Rob