From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: problems in commit 2d4dc890b5c8 (block: add helpers to run flush_dcache_page() against a bio and a request's pages) Date: Thu, 10 Dec 2009 14:03:53 -0800 (PST) Message-ID: <20091210.140353.219266447.davem@davemloft.net> References: <1260478776.2457.141.camel@mulgrave.site> <20091211002700.0600d327.isloginov@gmail.com> <1260482418.2457.208.camel@mulgrave.site> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:37182 "EHLO sunset.davemloft.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761777AbZLJWDr (ORCPT ); Thu, 10 Dec 2009 17:03:47 -0500 In-Reply-To: <1260482418.2457.208.camel@mulgrave.site> Sender: linux-arch-owner@vger.kernel.org List-ID: To: James.Bottomley@HansenPartnership.com Cc: isloginov@gmail.com, jens.axboe@oracle.com, linux-arch@vger.kernel.org From: James Bottomley Date: Thu, 10 Dec 2009 16:00:18 -0600 > On Fri, 2009-12-11 at 00:27 +0300, Ilya Loginov wrote: >> On Thu, 10 Dec 2009 14:59:36 -0600 >> James Bottomley wrote: >> >> > To fix mips, you just need a >> > flush_kernel_dcache_page() in slram_read so that the alias is updated >> > after the memcpy. >> >> I think you right. But! If we choose this way: >> >> First. We need to realize flush_kernel_dcache_page() for many >> architectures. Am I right? > > Actually, I think only sparc and mips need it. It's only needed for an > aliasing architecture. Next, it's only used for pio drivers, so if the > platform never uses a pio driver, it can get away without having this > (that's the sparc case, I think). Sparc has PIO drivers, namely IDE, and we have special flushes inserted into the IDE string PIO routines to handle that case.