From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from parcelfarce.linux.theplanet.co.uk ([195.92.249.252]:22748 "EHLO www.linux.org.uk") by vger.kernel.org with ESMTP id S268397AbUIQMoE (ORCPT ); Fri, 17 Sep 2004 08:44:04 -0400 Date: Fri, 17 Sep 2004 13:44:01 +0100 From: Matthew Wilcox Subject: Re: RFC: being more anal about iospace accesses.. Message-ID: <20040917124401.GR642@parcelfarce.linux.theplanet.co.uk> References: <1095287935.1688.4.camel@mulgrave> <20040916023325.GJ642@parcelfarce.linux.theplanet.co.uk> <20040916223042.GO642@parcelfarce.linux.theplanet.co.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: To: Linus Torvalds Cc: Matthew Wilcox , James Bottomley , Geert Uytterhoeven , Linux Arch list , Al Viro , Andrew Morton , Alan Cox , "David S. Miller" , Jeff Garzik List-ID: On Thu, Sep 16, 2004 at 03:42:34PM -0700, Linus Torvalds wrote: > On Thu, 16 Sep 2004, Matthew Wilcox wrote: > > 2004/09/14 torvalds | * They do _not_ update the port address. If you > > 2004/09/14 torvalds | * want MMIO that copies stuff laid out in MMIO > > 2004/09/14 torvalds | * memory across multiple ports, use "memcpy_toio()" > > 2004/09/14 torvalds | * and friends. > > > > That implies you can pass an iomap cookie to memcpy_toio() > > Actually, no it does not. It very much says "if you want __MMIO__ that > copies stuff". > > You can pass cookies the other way: if you create a cookie with the old > "ioremap()" interface (which means MMIO only, of course), I intended for > that to work well with the new interfaces (ioread/iowrite). But a > new-style IO-map cookie will _not_ work with the old interfaces. OK, you're thinking in x86-specific terms and I'm thinking in PA-specific terms ;-) I don't particularly want to be able to memcpy_fooio() on ioport space. But I do want to be able to memcpy_fooio() on big-endian mmio space and I do want to design the iomap cookies such that you can't pass the old ioremap cookies to the new interface. -- "Next the statesmen will invent cheap lies, putting the blame upon the nation that is attacked, and every man will be glad of those conscience-soothing falsities, and will diligently study them, and refuse to examine any refutations of them; and thus he will by and by convince himself that the war is just, and will thank God for the better sleep he enjoys after this process of grotesque self-deception." -- Mark Twain