From owner-svn-src-head@freebsd.org Tue Aug 4 23:50:29 2015 Return-Path: Delivered-To: svn-src-head@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 CDAAA9B310E; Tue, 4 Aug 2015 23:50:29 +0000 (UTC) (envelope-from jason.harmening@gmail.com) Received: from mail-ob0-x22b.google.com (mail-ob0-x22b.google.com [IPv6:2607:f8b0:4003:c01::22b]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 907B8771; Tue, 4 Aug 2015 23:50:29 +0000 (UTC) (envelope-from jason.harmening@gmail.com) Received: by obnw1 with SMTP id w1so19447014obn.3; Tue, 04 Aug 2015 16:50:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=subject:to:references:cc:from:message-id:date:user-agent :mime-version:in-reply-to:content-type:content-transfer-encoding; bh=TjgkAr/GHwliK7jHItvP6+YaZzeAYu9UWZFlqtE5ePA=; b=roV6CuKOh+QsriaIwnLAjwQs/hkXLQS2q6fBBbVPV4dWYbEt3X2cLMEaxsS61rS5La rNXiJzEFIpZlDUaiMl/FfTjQVJWy0Du0B1ujvznDn9wo0yNyRTlW2xWffy4sKDYzUI58 yFhQzGLdBqXlNmXaHp/5ejsbxRei+I/M+fTthUlop+N+doH09J88tQaBnGW2CFVpSI8f dIaPdquzAosVTJuVBejliEFDd5CfIUUiR3mCxl59XND13Mtl6btqX4OASlY5dy5ytMfh vA3dDjxtZVepo788Wn7pctGEW2Sv0Ziqc9dncL8bFVyTmKAXMUUlRJ50bX1TTjPYWdQx V/Ag== X-Received: by 10.182.158.200 with SMTP id ww8mr4810082obb.53.1438732228911; Tue, 04 Aug 2015 16:50:28 -0700 (PDT) Received: from corona.austin.rr.com (cpe-72-177-6-10.austin.res.rr.com. [72.177.6.10]) by smtp.googlemail.com with ESMTPSA id r3sm606809oia.22.2015.08.04.16.50.27 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 04 Aug 2015 16:50:28 -0700 (PDT) Subject: Re: svn commit: r286296 - in head/sys: amd64/amd64 arm/arm arm/include arm64/arm64 i386/i386 i386/include mips/mips powerpc/aim powerpc/booke powerpc/include powerpc/powerpc sparc64/include sparc64/spa... To: "Bjoern A. Zeeb" , "Jason A. Harmening" References: <201508041946.t74JkExD070238@repo.freebsd.org> Cc: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org From: Jason Harmening Message-ID: <55C150A3.4030509@gmail.com> Date: Tue, 4 Aug 2015 18:54:11 -0500 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:38.0) Gecko/20100101 Thunderbird/38.1.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 04 Aug 2015 23:50:29 -0000 On 08/04/15 18:22, Bjoern A. Zeeb wrote: > >> On 04 Aug 2015, at 19:46 , Jason A. Harmening wrote: >> >> Author: jah >> Date: Tue Aug 4 19:46:13 2015 >> New Revision: 286296 >> URL: https://svnweb.freebsd.org/changeset/base/286296 >> >> Log: >> Add two new pmap functions: >> vm_offset_t pmap_quick_enter_page(vm_page_t m) >> void pmap_quick_remove_page(vm_offset_t kva) >> >> These will create and destroy a temporary, CPU-local KVA mapping of a specified page. >> >> Guarantees: >> --Will not sleep and will not fail. >> --Safe to call under a non-sleepable lock or from an ithread >> >> Restrictions: >> --Not guaranteed to be safe to call from an interrupt filter or under a spin mutex on all platforms >> --Current implementation does not guarantee more than one page of mapping space across all platforms. MI code should not make nested calls to pmap_quick_enter_page. >> --MI code should not perform locking while holding onto a mapping created by pmap_quick_enter_page >> >> The idea is to use this in busdma, for bounce buffer copies as well as virtually-indexed cache maintenance on mips and arm. >> >> NOTE: the non-i386, non-amd64 implementations of these functions still need review and testing. > > Most of this description should go into a section 9 man page rather than the commit message ;-) > > /bz > Yep, I'm planning to write one.