From owner-freebsd-hackers@FreeBSD.ORG Mon Feb 2 08:46:09 2009 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 74DE610657A2 for ; Mon, 2 Feb 2009 08:46:09 +0000 (UTC) (envelope-from yanefbsd@gmail.com) Received: from fk-out-0910.google.com (fk-out-0910.google.com [209.85.128.185]) by mx1.freebsd.org (Postfix) with ESMTP id F3C0B8FC24 for ; Mon, 2 Feb 2009 08:46:08 +0000 (UTC) (envelope-from yanefbsd@gmail.com) Received: by fk-out-0910.google.com with SMTP id f40so1199314fka.11 for ; Mon, 02 Feb 2009 00:46:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:cc:content-type :content-transfer-encoding; bh=1xRqX5WR2osZ0e9HZ4Pk0Ybzd7RRsMr5sZmJ2Femj0g=; b=TnrGKh9eXlGgaoelwSocUqwi4g7LjW9vuqXZ8J1E+j8gZNyB7lNLmMo3D3zqMYOk1u iE8yR0bWx2ZaJSeIUfiBIw7PeOtZLZjPcNDuQuEmkiX0LegW/G5rLy6jMBZ5/OCRdT+O gqhLZG00u1M2Z7Rtul+D7RVoTXMBYfoGwm2HM= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=WUAhNm4XHf0Ls4068MZYs+EKgmlhxdZjV7Mo++ddWUd0DWrINDJklLN4xMuw1LHkra jjDmo5hAr0iHeg92DTILpB5+oAUem7LgAPJpAayPl+j0UnGjV60XB0EA9Hy59+w5FY0f 24eqkMT6vFfCZKGTtSMtVE1YZsIT1ZcUQ3X/s= MIME-Version: 1.0 Received: by 10.181.145.6 with SMTP id x6mr1600999bkn.25.1233564367501; Mon, 02 Feb 2009 00:46:07 -0800 (PST) In-Reply-To: <7d6fde3d0902020045h55255cane0d6dd9f64d23f5@mail.gmail.com> References: <6699015.16785.1233539817447.JavaMail.root@vms063.mailsrvcs.net> <7d6fde3d0902020045h55255cane0d6dd9f64d23f5@mail.gmail.com> Date: Mon, 2 Feb 2009 00:46:07 -0800 Message-ID: <7d6fde3d0902020046o7640f217ye88336b53920a538@mail.gmail.com> From: Garrett Cooper To: Sergey Babkin Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: bsd.quest@googlemail.com, freebsd-hackers@freebsd.org Subject: Re: bus_dma (9). What exactly means "Loading of memory allocation" ? X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 02 Feb 2009 08:46:12 -0000 On Mon, Feb 2, 2009 at 12:45 AM, Garrett Cooper wrote: > On Sun, Feb 1, 2009 at 5:56 PM, Sergey Babkin wrote: >> >> If I remember correctly, loading means that the pages become mapped >> and visible to the devices. Some buses can access only a limited >> address space , like ISA has only a 24-bit address. When a map gets >> loaded, for any pages outside of this range the temporary in-ramge >> pages are allocated and the d ata gets moved through them. On some >> machines, like I think DEC Alpha, the physicall addresses seen by >> the devices are not the same as seen by the CPU , these need to be >> translated. And so on. >> I think my real old articl e had some of these explanations but now >> the Daemonnews site seems to be re al slow: >> http://ezine.daemonnews.org/200008/isa.html >> -SB >> (sorry a bout top quoting, it's the only kind the web interface of my >> provider suppo rts) >> Feb 1, 2009 03:38:27 PM, [1]bsd.quest@googlemail.com wrote: >> >> Hi, >> at first the cut of text from man (9) bus_dma: >> bus_dmamap_t >> A machine-dependent opaque type describing an individual >> mapp ing. >> One map is used for each memory allocation that will b e loaded. >> Maps can be reused once they have been unloaded.. . >> Question: What exactly means "Loading of memory allocation" in thi s context >> ? >> Could anyone explain it or give me some little example wi th DMA >> functions >> for understanding it. > > Unfortunately it's bad English, so that might be where some of the > confusion is stemming from. I'll send a doc's PR request after this to > fix it. > -Garrett Ugh. Nevermind. The question was written improperly -- the manpage wasn't ><. -Garrett