Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261405AbUCUWeQ (ORCPT ); Sun, 21 Mar 2004 17:34:16 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261410AbUCUWeQ (ORCPT ); Sun, 21 Mar 2004 17:34:16 -0500 Received: from parcelfarce.linux.theplanet.co.uk ([195.92.249.252]:33959 "EHLO www.linux.org.uk") by vger.kernel.org with ESMTP id S261405AbUCUWeP (ORCPT ); Sun, 21 Mar 2004 17:34:15 -0500 Message-ID: <405E1859.5030906@pobox.com> Date: Sun, 21 Mar 2004 17:34:01 -0500 From: Jeff Garzik User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4) Gecko/20030703 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Russell King CC: Linus Torvalds , David Woodhouse , Christoph Hellwig , William Lee Irwin III , Andrew Morton , Andrea Arcangeli , linux-kernel@vger.kernel.org Subject: Re: can device drivers return non-ram via vm_ops->nopage? References: <20040320144022.GC2045@holomorphy.com> <20040320150621.GO9009@dualathlon.random> <20040320121345.2a80e6a0.akpm@osdl.org> <20040320205053.GJ2045@holomorphy.com> <20040320222639.K6726@flint.arm.linux.org.uk> <20040320224500.GP2045@holomorphy.com> <1079901914.17681.317.camel@imladris.demon.co.uk> <20040321204931.A11519@infradead.org> <1079902670.17681.324.camel@imladris.demon.co.uk> <20040321222327.D26708@flint.arm.linux.org.uk> In-Reply-To: <20040321222327.D26708@flint.arm.linux.org.uk> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 871 Lines: 22 Russell King wrote: > What about the case where the buffer is scatter-gather in nature, > just like we're so fond of telling driver writers who want to grab > (eg) 1MB of contiguous kernel memory for video buffers and the like? > Do we really want to tell driver writers to walk over 1MB of pages, > page by page, inserting them into the processes page tables via > remap_area_pages()? Tell driver writers to call a standard platform function with a {dma|mmio|pio|vmalloc} handle+size+len for {dma|mmio|pio|vmalloc} mmap setup, and {fault|nopage} handler. ;-) IMO they shouldn't have to care about the details. Jeff - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/