Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261741AbUCVFLz (ORCPT ); Mon, 22 Mar 2004 00:11:55 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261731AbUCVFLz (ORCPT ); Mon, 22 Mar 2004 00:11:55 -0500 Received: from gate.crashing.org ([63.228.1.57]:39657 "EHLO gate.crashing.org") by vger.kernel.org with ESMTP id S261744AbUCVFLu (ORCPT ); Mon, 22 Mar 2004 00:11:50 -0500 Subject: Re: can device drivers return non-ram via vm_ops->nopage? From: Benjamin Herrenschmidt To: Russell King Cc: Jeff Garzik , Linus Torvalds , David Woodhouse , Christoph Hellwig , William Lee Irwin III , Andrew Morton , Andrea Arcangeli , Linux Kernel list In-Reply-To: <20040322002041.I26708@flint.arm.linux.org.uk> References: <20040321204931.A11519@infradead.org> <1079902670.17681.324.camel@imladris.demon.co.uk> <20040321222327.D26708@flint.arm.linux.org.uk> <405E1859.5030906@pobox.com> <20040321225117.F26708@flint.arm.linux.org.uk> <405E23A5.7080903@pobox.com> <405E2F0D.3050001@pobox.com> <20040322002041.I26708@flint.arm.linux.org.uk> Content-Type: text/plain Message-Id: <1079931449.912.183.camel@gaston> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.5 Date: Mon, 22 Mar 2004 15:57:29 +1100 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 743 Lines: 19 > exists because architectures haven't defined their private > pgprot_writecombine() implementations, preferring instead to add > to the preprocessor junk instead. And it's not even about writecombine... Like writecombine is an attribute of the PCI host bridge on pmacs, not a pgprot, while cacheability issues cannot be always abstracted the same way on different archs. Actually, GUARDED could be used for !writecombine on ppc, but !GUARDED would allow prefetch and out of order IOs.... Ben. - 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/