From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756071Ab0IGJNM (ORCPT ); Tue, 7 Sep 2010 05:13:12 -0400 Received: from mail-ey0-f174.google.com ([209.85.215.174]:55761 "EHLO mail-ey0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755885Ab0IGJNH (ORCPT ); Tue, 7 Sep 2010 05:13:07 -0400 Message-ID: <4C8601C0.40001@mvista.com> Date: Tue, 07 Sep 2010 13:11:28 +0400 From: Sergei Shtylyov User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-GB; rv:1.9.2.8) Gecko/20100802 Thunderbird/3.1.2 MIME-Version: 1.0 To: Kevin Cernekee CC: Ralf Baechle , dediao@cisco.com, dvomlehn@cisco.com, linux-mips@linux-mips.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/5] MIPS: HIGHMEM DMA on noncoherent MIPS32 processors References: <7d28a475591d9522bd1841a95fe21260@localhost> In-Reply-To: <7d28a475591d9522bd1841a95fe21260@localhost> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello. On 07-09-2010 8:03, Kevin Cernekee wrote: > The MIPS DMA coherency functions do not work properly (i.e. kernel oops) > when HIGHMEM pages are passed in as arguments. This patch uses the PPC > approach of calling kmap_atomic() with IRQs disabled to temporarily map > high pages, in order to flush them out to memory. > Signed-off-by: Dezhong Diao > Signed-off-by: Kevin Cernekee > --- > arch/mips/mm/dma-default.c | 159 ++++++++++++++++++++++---------------------- > 1 files changed, 80 insertions(+), 79 deletions(-) > diff --git a/arch/mips/mm/dma-default.c b/arch/mips/mm/dma-default.c > index 469d401..3f23952 100644 > --- a/arch/mips/mm/dma-default.c > +++ b/arch/mips/mm/dma-default.c [...] > @@ -191,8 +231,8 @@ void dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size, > enum dma_data_direction direction) > { > if (cpu_is_noncoherent_r10000(dev)) > - __dma_sync(dma_addr_to_virt(dev, dma_addr), size, > - direction); > + __dma_sync(dma_addr_to_page(dev, dma_addr), > + (dma_addr & ~PAGE_MASK), size, direction); Parens are not needed here. > @@ -277,15 +297,10 @@ EXPORT_SYMBOL(dma_sync_single_for_cpu); > void dma_sync_single_for_device(struct device *dev, dma_addr_t dma_handle, > size_t size, enum dma_data_direction direction) > { > - BUG_ON(direction == DMA_NONE); > - > plat_extra_sync_for_device(dev); > - if (!plat_device_is_coherent(dev)) { > - unsigned long addr; > - > - addr = dma_addr_to_virt(dev, dma_handle); > - __dma_sync(addr, size, direction); > - } > + if (!plat_device_is_coherent(dev)) > + __dma_sync(dma_addr_to_page(dev, dma_handle), > + (dma_handle & ~PAGE_MASK), size, direction); Here as well... WBR, Sergei