From owner-svn-src-all@freebsd.org Sun Jan 14 08:30:45 2018 Return-Path: Delivered-To: svn-src-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id A0881EB3BF6; Sun, 14 Jan 2018 08:30:45 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from kib.kiev.ua (kib.kiev.ua [IPv6:2001:470:d5e7:1::1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 19E727251D; Sun, 14 Jan 2018 08:30:44 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from tom.home (kib@localhost [127.0.0.1]) by kib.kiev.ua (8.15.2/8.15.2) with ESMTPS id w0E8UaiA020012 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Sun, 14 Jan 2018 10:30:40 +0200 (EET) (envelope-from kostikbel@gmail.com) DKIM-Filter: OpenDKIM Filter v2.10.3 kib.kiev.ua w0E8UaiA020012 Received: (from kostik@localhost) by tom.home (8.15.2/8.15.2/Submit) id w0E8UaAq020011; Sun, 14 Jan 2018 10:30:36 +0200 (EET) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: tom.home: kostik set sender to kostikbel@gmail.com using -f Date: Sun, 14 Jan 2018 10:30:36 +0200 From: Konstantin Belousov To: Nathan Whitehorn Cc: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r327950 - in head/sys/powerpc: aim include powerpc ps3 Message-ID: <20180114083036.GX1684@kib.kiev.ua> References: <201801132314.w0DNEra5002692@repo.freebsd.org> <20180113232441.GV1684@kib.kiev.ua> <010d0153-8931-a3c2-db21-dfcbaf848fc0@freebsd.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.2 (2017-12-15) X-Spam-Status: No, score=-2.0 required=5.0 tests=ALL_TRUSTED,BAYES_00, DKIM_ADSP_CUSTOM_MED,FREEMAIL_FROM,NML_ADSP_CUSTOM_MED autolearn=no autolearn_force=no version=3.4.1 X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on tom.home X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 14 Jan 2018 08:30:45 -0000 On Sat, Jan 13, 2018 at 08:31:40PM -0800, Nathan Whitehorn wrote: > > > On 01/13/18 15:28, Nathan Whitehorn wrote: > > > > > > On 01/13/18 15:24, Konstantin Belousov wrote: > >> On Sat, Jan 13, 2018 at 11:14:53PM +0000, Nathan Whitehorn wrote: > >>> +/* > >>> + * We (usually) have a direct map of all physical memory. All > >>> + * uses of this macro must be gated by a check on hw_direct_map! > >>> + * The location of the direct map may not be 1:1 in future, so use > >>> + * of the macro is recommended; it may also grow an assert that > >>> hw_direct_map > >>> + * is set. > >>> + */ > >>> +#define PHYS_TO_DMAP(x) x > >>> +#define DMAP_TO_PHYS(x) x > >> Take a look at the sys/vm/vm_page.c:vm_page_free_prep() function. > >> > > > > I think the checks in there should work as designed, unless I'm > > missing something. Am I? > > -Nathan > > > > Actually, wait, this is broken if hw_direct_map is not set. I can do an > #ifdef __powerpc__ hack, but do you have opinions for a better MI flag > for "yes, the macro is defined but, no, the direct map may not be > available"? Exactly. You explicitly noted the need to check for the hw_direct_map in the comment, so I did not see a need to explain further. We intended that PHYS_TO_DMAP/DMAP_TO_PHYS become MI KPI. If the symbols are present, their semantic is the unconditional presence and usability of the direct map. sf bufs were rototiled with things like SFBUF_OPTIONAL_DIRECT_MAP, but I dislike it and hope that PHYS_TO_DMAP would be not damaged this way.