From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Wei Hu (Xavier)" Subject: Re: [PATCH for-next 2/4] RDMA/hns: Add IOMMU enable support in hip08 Date: Thu, 9 Nov 2017 09:26:27 +0800 Message-ID: <5A03AEC3.10109@huawei.com> References: <1506763741-81429-1-git-send-email-xavier.huwei@huawei.com> <1506763741-81429-3-git-send-email-xavier.huwei@huawei.com> <20170930161023.GI2965@mtr-leonro.local> <59DF60A3.7080803@huawei.com> <5fe5f9b9-2c2b-ab3c-dafa-3e2add051bbb@arm.com> <59F97BBE.5070207@huawei.com> <5A011E49.6060407@huawei.com> <20171107154838.GC21466@ziepe.ca> <20171107155805.GA24082@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20171107155805.GA24082-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Christoph Hellwig , Jason Gunthorpe Cc: Robin Murphy , Leon Romanovsky , shaobo.xu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, xavier.huwei-WVlzvzqoTvw@public.gmane.org, lijun_nudt-9Onoh4P/yGk@public.gmane.org, oulijun-hv44wF8Li93QT0dZR+AlfA@public.gmane.org, linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, charles.chenxin-hv44wF8Li93QT0dZR+AlfA@public.gmane.org, linuxarm-hv44wF8Li93QT0dZR+AlfA@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, dledford-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, liuyixian-hv44wF8Li93QT0dZR+AlfA@public.gmane.org, zhangxiping3-hv44wF8Li93QT0dZR+AlfA@public.gmane.org, shaoboxu-WVlzvzqoTvw@public.gmane.org List-Id: iommu@lists.linux-foundation.org On 2017/11/7 23:58, Christoph Hellwig wrote: > On Tue, Nov 07, 2017 at 08:48:38AM -0700, Jason Gunthorpe wrote: >> Can't you just use vmalloc and dma_map that? Other drivers follow that >> approach.. > You can't easily due to the flushing requirements. We used to do that > in XFS and it led to problems. You need the page allocator + vmap + > invalidate_kernel_vmap_range + flush_kernel_vmap_range to get the > cache flushing right. > > . Hi, Christoph Hellwig Thanks for your suggestion. Regards Wei Hu -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-it0-f71.google.com (mail-it0-f71.google.com [209.85.214.71]) by kanga.kvack.org (Postfix) with ESMTP id CB100440460 for ; Wed, 8 Nov 2017 20:27:19 -0500 (EST) Received: by mail-it0-f71.google.com with SMTP id p138so6996093itp.9 for ; Wed, 08 Nov 2017 17:27:19 -0800 (PST) Received: from huawei.com ([45.249.212.32]) by mx.google.com with ESMTP id l101si4582769ioi.243.2017.11.08.17.27.18 for ; Wed, 08 Nov 2017 17:27:19 -0800 (PST) Subject: Re: [PATCH for-next 2/4] RDMA/hns: Add IOMMU enable support in hip08 References: <1506763741-81429-1-git-send-email-xavier.huwei@huawei.com> <1506763741-81429-3-git-send-email-xavier.huwei@huawei.com> <20170930161023.GI2965@mtr-leonro.local> <59DF60A3.7080803@huawei.com> <5fe5f9b9-2c2b-ab3c-dafa-3e2add051bbb@arm.com> <59F97BBE.5070207@huawei.com> <5A011E49.6060407@huawei.com> <20171107154838.GC21466@ziepe.ca> <20171107155805.GA24082@infradead.org> From: "Wei Hu (Xavier)" Message-ID: <5A03AEC3.10109@huawei.com> Date: Thu, 9 Nov 2017 09:26:27 +0800 MIME-Version: 1.0 In-Reply-To: <20171107155805.GA24082@infradead.org> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Christoph Hellwig , Jason Gunthorpe Cc: Robin Murphy , Leon Romanovsky , shaobo.xu@intel.com, xavier.huwei@tom.com, lijun_nudt@163.com, oulijun@huawei.com, linux-rdma@vger.kernel.org, charles.chenxin@huawei.com, linuxarm@huawei.com, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, dledford@redhat.com, liuyixian@huawei.com, zhangxiping3@huawei.com, shaoboxu@tom.com On 2017/11/7 23:58, Christoph Hellwig wrote: > On Tue, Nov 07, 2017 at 08:48:38AM -0700, Jason Gunthorpe wrote: >> Can't you just use vmalloc and dma_map that? Other drivers follow that >> approach.. > You can't easily due to the flushing requirements. We used to do that > in XFS and it led to problems. You need the page allocator + vmap + > invalidate_kernel_vmap_range + flush_kernel_vmap_range to get the > cache flushing right. > > . Hi, Christoph Hellwig Thanks for your suggestion. Regards Wei Hu -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753055AbdKIB0v (ORCPT ); Wed, 8 Nov 2017 20:26:51 -0500 Received: from szxga06-in.huawei.com ([45.249.212.32]:59629 "EHLO huawei.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1752908AbdKIB0u (ORCPT ); Wed, 8 Nov 2017 20:26:50 -0500 Subject: Re: [PATCH for-next 2/4] RDMA/hns: Add IOMMU enable support in hip08 To: Christoph Hellwig , Jason Gunthorpe References: <1506763741-81429-1-git-send-email-xavier.huwei@huawei.com> <1506763741-81429-3-git-send-email-xavier.huwei@huawei.com> <20170930161023.GI2965@mtr-leonro.local> <59DF60A3.7080803@huawei.com> <5fe5f9b9-2c2b-ab3c-dafa-3e2add051bbb@arm.com> <59F97BBE.5070207@huawei.com> <5A011E49.6060407@huawei.com> <20171107154838.GC21466@ziepe.ca> <20171107155805.GA24082@infradead.org> CC: Robin Murphy , Leon Romanovsky , , , , , , , , , , , , , , From: "Wei Hu (Xavier)" Message-ID: <5A03AEC3.10109@huawei.com> Date: Thu, 9 Nov 2017 09:26:27 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 MIME-Version: 1.0 In-Reply-To: <20171107155805.GA24082@infradead.org> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.57.115.182] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2017/11/7 23:58, Christoph Hellwig wrote: > On Tue, Nov 07, 2017 at 08:48:38AM -0700, Jason Gunthorpe wrote: >> Can't you just use vmalloc and dma_map that? Other drivers follow that >> approach.. > You can't easily due to the flushing requirements. We used to do that > in XFS and it led to problems. You need the page allocator + vmap + > invalidate_kernel_vmap_range + flush_kernel_vmap_range to get the > cache flushing right. > > . Hi, Christoph Hellwig Thanks for your suggestion. Regards Wei Hu