From mboxrd@z Thu Jan 1 00:00:00 1970 From: Russell King Subject: Re: DMA from user space buffer/VIPT cache flushing wows (was: Minutes: 21 Sept,09 RMK meeting) Date: Wed, 11 Nov 2009 19:29:45 +0000 Message-ID: <20091111192945.GA31608@flint.arm.linux.org.uk> References: <20091027163551.GA1446@flint.arm.linux.org.uk> <20091028.143432.241464826.Hiroshi.DOYU@nokia.com> <20091028174920.GA20945@flint.arm.linux.org.uk> <20091029.151251.45877478.Hiroshi.DOYU@nokia.com> <20091029133703.GA3860@flint.arm.linux.org.uk> <20091106151558.GA7986@localhost> <20091108184753.GA31433@flint.arm.linux.org.uk> <20091109001509.GB28928@localhost> <20091109101056.GA29621@flint.arm.linux.org.uk> <20091110160334.GE734@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from caramon.arm.linux.org.uk ([78.32.30.218]:57441 "EHLO caramon.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758514AbZKKT3w (ORCPT ); Wed, 11 Nov 2009 14:29:52 -0500 Content-Disposition: inline In-Reply-To: <20091110160334.GE734@localhost> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Imre Deak Cc: Paul Mundt , linux-arch@vger.kernel.org, "Doyu Hiroshi (Nokia-D/Helsinki)" , "vikram.pandita@ti.com" , "tony@atomide.com" , "rak@arm.linux.org.uk" , "rhishi@ti.com" , "r-woodruff2@ti.com" , "laurent.pinchart@ideasonboard.com" , "Syrjala Ville (Nokia-D/Helsinki)" On Tue, Nov 10, 2009 at 06:03:34PM +0200, Imre Deak wrote: > Additionally as I said we would need a kernel interface for flushing > user space buffers and mlock is not exposed to drivers. For that we > would also need to add reference counting for mlock. Oh, and let me re-iterate: the purpose of the patch I supplied to Texas was to solve _their_ specific problem, which is to get the DSP bridge driver working. It is *not* a generic interface for kernel drivers to use. That's why I ignored your comment about kernel interfaces for flusing userspace buffers. It's just not relevant to the problem at hand. -- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: