Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Tue, 9 Aug 2022 13:15:49 +0200
From:   Borislav Petkov <bp@alien8.de>
To:     Justin He <Justin.He@arm.com>
Cc:     "Kani, Toshi" <toshi.kani@hpe.com>,
        "Rafael J. Wysocki" <rafael@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>,
        Shuai Xue <xueshuai@linux.alibaba.com>,
        Jarkko Sakkinen <jarkko@kernel.org>,
        ACPI Devel Maling List <linux-acpi@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        "open list:EDAC-CORE" <linux-edac@vger.kernel.org>
Subject: Re: =?utf-8?B?5Zue5aSNOiBbUEFUQ0hdIEFDUEk=?= =?utf-8?Q?=3A?= APEI:
 move edac_init ahead of ghes platform drv register
Message-ID: <YvJB5cxSldpigw1g@zn.tnic>
References: <20220805023200.154634-1-justin.he@arm.com>
 <CAJZ5v0gUbKYaxRcZsYO6eq7vLgKdgfdLdoL_Hzmd6r-JczkVPg@mail.gmail.com>
 <YvFX9vTilqMpsF9u@zn.tnic>
 <PH7PR84MB1838379B8C2DF488DE729A9182639@PH7PR84MB1838.NAMPRD84.PROD.OUTLOOK.COM>
 <YvF4p01WJGGUwIJC@zn.tnic>
 <PH7PR84MB1838492812F5ABAA4BB54D9982639@PH7PR84MB1838.NAMPRD84.PROD.OUTLOOK.COM>
 <YvF+J/dfyOEVSbSQ@zn.tnic>
 <PH7PR84MB1838BF4F8B56EF1E24FCF1DC82639@PH7PR84MB1838.NAMPRD84.PROD.OUTLOOK.COM>
 <YvIPf/m3hU46S9Ik@zn.tnic>
 <DBBPR08MB4538A5C080B09A96A77CCDA9F7629@DBBPR08MB4538.eurprd08.prod.outlook.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
In-Reply-To: <DBBPR08MB4538A5C080B09A96A77CCDA9F7629@DBBPR08MB4538.eurprd08.prod.outlook.com>
Precedence: bulk

On Tue, Aug 09, 2022 at 09:24:33AM +0000, Justin He wrote:
> If no, what is the detail logic of ghes_edac_driver_is_preferred()?

That should be moved from ghes_edac.c to ghes.c:

/*
 * Known systems that are safe to enable this module.
 */
static struct acpi_platform_list plat_list[] = {
        {"HPE   ", "Server  ", 0, ACPI_SIG_FADT, all_versions},
        { } /* End */
};

and then

bool ghes_edac_driver_is_preferred()
{
	if (IS_ENABLED(CONFIG_X86)) {
                /* Check if safe to enable on this system */
                idx = acpi_match_platform_list(plat_list);
	} else if (ARM) {
		/* insert ARM logic here */
	}
}

That function should be called by the EDAC modules which compete with
ghes_edac.

In the x86 case, that's sb_edac, skx_edac and amd64_edac, I guess.

It all depends on what platforms Toshi wants to load it - I'm guessing
HPE has both Intel and AMD platforms where they prefer ghes_edac.

On ARM, that's up to ARM folks.

> Because I notice that lots of other edac drivers are probing like:
> ...
>         owner = edac_get_owner();
>         if (owner && strncmp(owner, EDAC_MOD_STR, sizeof(EDAC_MOD_STR)))
>                 return -EBUSY;

No, that's a silly mechanism to allow a single EDAC driver to load on
the system. But your test will go before it, at the very beginning of
the init function.

HTH.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette