RE: [PATCH 2/2] EDAC/ghes: Modularize ghes_edac driver to remove the dependency on ghes

[Justin He <Justin.He@arm.com>]

Hi Boris and Toshi

> -----Original Message-----
> From: Borislav Petkov <bp@alien8.de>
> Sent: Friday, August 12, 2022 10:46 PM
> To: Justin He <Justin.He@arm.com>
> Cc: Ard Biesheuvel <ardb@kernel.org>; Len Brown <lenb@kernel.org>; James
> Morse <James.Morse@arm.com>; Tony Luck <tony.luck@intel.com>; Mauro
> Carvalho Chehab <mchehab@kernel.org>; Robert Richter <rric@kernel.org>;
> Robert Moore <robert.moore@intel.com>; linux-acpi@vger.kernel.org;
> linux-kernel@vger.kernel.org; linux-edac@vger.kernel.org; devel@acpica.org;
> Rafael J . Wysocki <rafael@kernel.org>; Shuai Xue
> <xueshuai@linux.alibaba.com>; Jarkko Sakkinen <jarkko@kernel.org>;
> linux-efi@vger.kernel.org; nd <nd@arm.com>; toshi.kani@hpe.com;
> stable@kernel.org
> Subject: Re: [PATCH 2/2] EDAC/ghes: Modularize ghes_edac driver to remove
> the dependency on ghes
> 
> On Thu, Aug 11, 2022 at 09:17:13AM +0000, Jia He wrote:
> > diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c index
> > d91ad378c00d..ed6519f3d45b 100644
> > --- a/drivers/acpi/apei/ghes.c
> > +++ b/drivers/acpi/apei/ghes.c
> > @@ -94,6 +94,8 @@
> >  #define FIX_APEI_GHES_SDEI_CRITICAL	__end_of_fixed_addresses
> >  #endif
> >
> > +ATOMIC_NOTIFIER_HEAD(ghes_report_chain);
> 
> static. You need function wrappers which call the notifier from the module.
> 
Ok

> Also, why atomic? x86_mce_decoder_chain is a blocking one.
> 
But is ghes_proc_in_irq() in the irq context which can invoke the notifier?
I described it in the commit log:
>To resolve the build dependency of ghes_edac_report_mem_error() for ghes,
>introduce a notifier which is registered by ghes_edac module. atomic
>notifier is used because ghes_proc_in_irq() is in the irq context.

> Also, the whole notifier adding thing needs to be a separate patch.
Ok, I will try to cleanly split it

> 
> > @@ -1497,3 +1504,37 @@ void __init acpi_ghes_init(void)
> >  	else
> >  		pr_info(GHES_PFX "Failed to enable APEI firmware first mode.\n");
> > }
> > +
> > +/*
> > + * Known x86 systems that prefer GHES error reporting:
> > + */
> > +static struct acpi_platform_list plat_list[] = {
> > +	{"HPE   ", "Server  ", 0, ACPI_SIG_FADT, all_versions},
> > +	{ } /* End */
> > +};
> > +
> > +struct list_head *ghes_get_devices(bool force) {
> > +	int idx = -1;
> > +
> > +	if (IS_ENABLED(CONFIG_X86)) {
> > +		idx = acpi_match_platform_list(plat_list);
> > +		if (idx < 0 && !force)
> > +			return NULL;
> > +	}
> > +
> > +	return &ghes_devs;
> > +}
> > +EXPORT_SYMBOL_GPL(ghes_get_devices);
> 
> And yes, as Toshi points out, the other EDAC drivers - sb_edac, skx_edac and
> amd64_edac - should call this function in their init functions so that it can get
> selected which driver to load on HPE server platforms.
> 
> Also in a separate patch pls.
> 
Ok, thanks

--
Cheers,
Justin (Jia He)