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From:   Thomas Gleixner <tglx@linutronix.de>
To:     hpa@zytor.com, Andrew Cooper <andrew.cooper3@citrix.com>,
        LKML <linux-kernel@vger.kernel.org>
Cc:     Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        x86@kernel.org, Jan Kiszka <jan.kiszka@siemens.com>,
        James Morris <jmorris@namei.org>,
        David Howells <dhowells@redhat.com>,
        Matthew Garrett <mjg59@google.com>,
        Josh Boyer <jwboyer@redhat.com>,
        Zhenzhong Duan <zhenzhong.duan@oracle.com>,
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        Dimitri Sivanich <dimitri.sivanich@hpe.com>,
        Arnd Bergmann <arnd@arndb.de>,
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        Len Brown <len.brown@intel.com>,
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        Martin Molnar <martin.molnar.programming@gmail.com>,
        Pingfan Liu <kernelfans@gmail.com>,
        jailhouse-dev@googlegroups.com
Subject: Re: [PATCH] x86/smpboot: Remove 486-isms from the modern AP boot path
In-Reply-To: <601E644A-B046-4030-B3BD-280ABF15BF53@zytor.com>
References: <20200325101431.12341-1-andrew.cooper3@citrix.com> <601E644A-B046-4030-B3BD-280ABF15BF53@zytor.com>
Date:   Wed, 25 Mar 2020 15:37:53 +0100
Message-ID: <87r1xgxzy6.fsf@nanos.tec.linutronix.de>
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hpa@zytor.com writes:
> On March 25, 2020 3:14:31 AM PDT, Andrew Cooper <andrew.cooper3@citrix.com> wrote:
>>@@ -1118,7 +1121,7 @@ static int do_boot_cpu(int apicid, int cpu,
>>struct task_struct *idle,
>> 		}
>> 	}
>> 
>>-	if (x86_platform.legacy.warm_reset) {
>>+	if (!APIC_INTEGRATED(boot_cpu_apic_version)) {
>> 		/*
>> 		 * Cleanup possible dangling ends...
>> 		 */
>
> We don't support SMP on 486 and haven't for a very long time. Is there
> any reason to retain that code at all?

Not that I'm aware off.

Thanks,

        tglx