From owner-svn-src-head@FreeBSD.ORG  Fri Feb  6 19:29:24 2015
Return-Path: <owner-svn-src-head@FreeBSD.ORG>
Delivered-To: svn-src-head@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115])
 (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits))
 (No client certificate requested)
 by hub.freebsd.org (Postfix) with ESMTPS id 1631ADEF;
 Fri,  6 Feb 2015 19:29:24 +0000 (UTC)
Received: from bigwig.baldwin.cx (bigwig.baldwin.cx [IPv6:2001:470:1f11:75::1])
 (using TLSv1 with cipher DHE-RSA-CAMELLIA256-SHA (256/256 bits))
 (Client did not present a certificate)
 by mx1.freebsd.org (Postfix) with ESMTPS id E44ABF8A;
 Fri,  6 Feb 2015 19:29:23 +0000 (UTC)
Received: from ralph.baldwin.cx (pool-173-54-116-245.nwrknj.fios.verizon.net
 [173.54.116.245])
 by bigwig.baldwin.cx (Postfix) with ESMTPSA id 066A0B93A;
 Fri,  6 Feb 2015 14:29:23 -0500 (EST)
From: John Baldwin <jhb@freebsd.org>
To: src-committers@freebsd.org
Subject: Re: svn commit: r278325 - in head/sys: amd64/amd64 i386/i386 x86/x86
Date: Fri, 06 Feb 2015 13:23:34 -0500
Message-ID: <3474953.fuLVXbEtbd@ralph.baldwin.cx>
User-Agent: KMail/4.14.2 (FreeBSD/10.1-STABLE; KDE/4.14.2; amd64; ; )
In-Reply-To: <201502061820.t16IK0w7052945@svn.freebsd.org>
References: <201502061820.t16IK0w7052945@svn.freebsd.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 7Bit
Content-Type: text/plain; charset="us-ascii"
X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.2.7
 (bigwig.baldwin.cx); Fri, 06 Feb 2015 14:29:23 -0500 (EST)
Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org
X-BeenThere: svn-src-head@freebsd.org
X-Mailman-Version: 2.1.18-1
Precedence: list
List-Id: SVN commit messages for the src tree for head/-current
 <svn-src-head.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/svn-src-head>,
 <mailto:svn-src-head-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/svn-src-head/>
List-Post: <mailto:svn-src-head@freebsd.org>
List-Help: <mailto:svn-src-head-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/svn-src-head>,
 <mailto:svn-src-head-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Fri, 06 Feb 2015 19:29:24 -0000

On Friday, February 06, 2015 06:20:00 PM John Baldwin wrote:
> Author: jhb
> Date: Fri Feb  6 18:19:59 2015
> New Revision: 278325
> URL: https://svnweb.freebsd.org/changeset/base/278325
> 
> Log:
>   Revert the IPI startup sequence to match what is described in the
>   Intel Multiprocessor Specification v1.4.  The Intel SDM claims that
>   the INIT IPIs here are invalid, but other systems follow the MP
>   spec instead.

All of the breakage here is my fault.  The original IPIs present in FreeBSD 3 
and 4 followed the MP spec.  However, the Intel SDM claims that some of the 
IPIs involved are invalid on modern hardware and doesn't use level trigger or 
a de-assert INIT in the reference code in the SDM.  The SDM is what led me to 
change the initial INIT to edge trigger.

One SDMism I did adopt here was to always set the interrupt asserted bit 
except in the special case of the INIT de-assert.

-- 
John Baldwin