From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Tue, 27 May 2003 12:45:57 +0100 (BST) Received: from p508B77C3.dip.t-dialin.net ([IPv6:::ffff:80.139.119.195]:61910 "EHLO dea.linux-mips.net") by linux-mips.org with ESMTP id ; Tue, 27 May 2003 12:45:55 +0100 Received: from dea.linux-mips.net (localhost [127.0.0.1]) by dea.linux-mips.net (8.12.8/8.12.8) with ESMTP id h4RBjpbY025287; Tue, 27 May 2003 04:45:51 -0700 Received: (from ralf@localhost) by dea.linux-mips.net (8.12.8/8.12.8/Submit) id h4RBjpcP025286; Tue, 27 May 2003 13:45:51 +0200 Date: Tue, 27 May 2003 13:45:51 +0200 From: Ralf Baechle To: Christoph Hellwig Cc: Atsushi Nemoto , wgowcher@yahoo.com, linux-mips@linux-mips.org Subject: Re: pci_alloc_consistent usage Message-ID: <20030527114551.GC24905@linux-mips.org> References: <20030523215935.71373.qmail@web11901.mail.yahoo.com> <20030527091740.GA23296@linux-mips.org> <20030527.190749.39150100.nemoto@toshiba-tops.co.jp> <20030527115322.A7124@infradead.org> <20030527112237.GA24905@linux-mips.org> <20030527123329.A7750@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20030527123329.A7750@infradead.org> User-Agent: Mutt/1.4.1i Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 2462 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: ralf@linux-mips.org Precedence: bulk X-list: linux-mips On Tue, May 27, 2003 at 12:33:29PM +0100, Christoph Hellwig wrote: > On Tue, May 27, 2003 at 01:22:37PM +0200, Ralf Baechle wrote: > > [...] > > portably refer to any piece of memory. If you have a cpu pointer > > (which may be validly DMA'd too) you may easily obtain the page > > and offset using something like this: > > > > struct page *page = virt_to_page(ptr); > > unsigned long offset = ((unsigned long)ptr & ~PAGE_MASK); > > [...] > > > > While it's officially documented I still don't like it. > > Hmm, I remembered that some ports used vmalloc-like allocators for > this and virt_to_page doesn't work for those.. There's at least one MIPS system which we don't support anymore but which would have to be supported by something like this. Whatever - virt_to_page should then be considered a a legacy API which we have to try to support as well as possible in the hope it's going to fade away ... Ralf