RE: [PATCH v2 2/4] x86/mce/AMD; EDAC,amd64: Move find_umc_channel() to AMD mcheck

[Ghannam, Yazen]

> -----Original Message-----
> From: Borislav Petkov [mailto:bp@xxxxxxxxx]
> Sent: Wednesday, March 22, 2017 5:17 PM
> To: Ghannam, Yazen <Yazen.Ghannam@xxxxxxx>
> Cc: linux-edac@xxxxxxxxxxxxxxx; Tony Luck <tony.luck@xxxxxxxxx>;
> x86@xxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH v2 2/4] x86/mce/AMD; EDAC,amd64: Move
> find_umc_channel() to AMD mcheck
> 
> On Mon, Mar 20, 2017 at 03:26:52PM -0500, Yazen Ghannam wrote:
> > We need to find a UMC's channel number from mcheck code when
> > translating UMC normalized addresses to system physical addresses. So
> > move the function there from EDAC.
> >
> > Also, drop the struct pvt from the function parameters since we don't
> > use it. And add a sanity check to make sure we're only looking at UMCs
> > in case the UMC instance IDs ever match up with other bank types.
> >
> > Signed-off-by: Yazen Ghannam <Yazen.Ghannam@xxxxxxx>
> > ---
> 
> ...
> 
> > diff --git a/arch/x86/kernel/cpu/mcheck/mce_amd.c
> > b/arch/x86/kernel/cpu/mcheck/mce_amd.c
> > index 524cc57..10fddcc 100644
> > --- a/arch/x86/kernel/cpu/mcheck/mce_amd.c
> > +++ b/arch/x86/kernel/cpu/mcheck/mce_amd.c
> > @@ -755,6 +755,27 @@ int umc_normaddr_to_sysaddr(u64 norm_addr,
> u16
> > nid, u8 umc, u64 *sys_addr)  }
> > EXPORT_SYMBOL_GPL(umc_normaddr_to_sysaddr);
> >
> > +/*
> > + * To find the UMC channel represented by this bank we need to match
> > +on its
> > + * instance_id. The instance_id of a bank is held in the lower 32
> > +bits of its
> > + * IPID.
> > + */
> > +int find_umc_channel(struct mce *m)
> > +{
> > +	u32 umc_instance_id[] = {0x50f00, 0x150f00};
> > +	u32 instance_id = m->ipid & GENMASK(31, 0);
> > +	int i, channel = -EINVAL;
> > +
> > +	if (smca_banks[m->bank].hwid &&
> > +	    smca_banks[m->bank].hwid->bank_type == SMCA_UMC)
> > +		for (i = 0; i < ARRAY_SIZE(umc_instance_id); i++)
> > +			if (umc_instance_id[i] == instance_id)
> > +				channel = i;
> > +
> > +	return channel;
> > +}
> > +EXPORT_SYMBOL_GPL(find_umc_channel);
> 
> This is an exported function now so it should have a prefix. Maybe
> "amd_find_umc_channel" or so.
> 

Okay, will do.

Thanks,
Yazen