From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754236AbcEWKoZ (ORCPT ); Mon, 23 May 2016 06:44:25 -0400 Received: from foss.arm.com ([217.140.101.70]:50000 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754170AbcEWKoV (ORCPT ); Mon, 23 May 2016 06:44:21 -0400 Subject: Re: [PATCH 4/5] iommu/rockchip: add ARM64 cache flush operation for iommu To: Shunqian Zheng , joro@8bytes.org, heiko@sntech.de, Catalin Marinas , Mark Rutland References: <1463967439-13354-1-git-send-email-zhengsq@rock-chips.com> <1463967439-13354-5-git-send-email-zhengsq@rock-chips.com> Cc: linux-rockchip@lists.infradead.org, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Simon From: Robin Murphy Message-ID: <5742DEFE.1040902@arm.com> Date: Mon, 23 May 2016 11:44:14 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.8.0 MIME-Version: 1.0 In-Reply-To: <1463967439-13354-5-git-send-email-zhengsq@rock-chips.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 23/05/16 02:37, Shunqian Zheng wrote: > From: Simon > > Signed-off-by: Simon > --- > drivers/iommu/rockchip-iommu.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/iommu/rockchip-iommu.c b/drivers/iommu/rockchip-iommu.c > index 043d18c..1741b65 100644 > --- a/drivers/iommu/rockchip-iommu.c > +++ b/drivers/iommu/rockchip-iommu.c > @@ -95,12 +95,16 @@ struct rk_iommu { > > static inline void rk_table_flush(u32 *va, unsigned int count) > { > +#if defined(CONFIG_ARM) > phys_addr_t pa_start = virt_to_phys(va); > phys_addr_t pa_end = virt_to_phys(va + count); > size_t size = pa_end - pa_start; > > __cpuc_flush_dcache_area(va, size); > outer_flush_range(pa_start, pa_end); > +#elif defined(CONFIG_ARM64) > + __dma_flush_range(va, va + count); > +#endif Ugh, please don't use arch-private cache maintenance functions directly from a driver. Allocating/mapping page tables to be read by the IOMMU is still DMA, so using the DMA APIs is the correct way to manage them, *especially* if it needs to work across multiple architectures. Robin. > } > > static struct rk_iommu_domain *to_rk_domain(struct iommu_domain *dom) >