From: "Wei Hu (Xavier)" <xavier.huwei@huawei.com>
To: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Robin Murphy <robin.murphy@arm.com>,
Leon Romanovsky <leon@kernel.org>, <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>
Subject: Re: [PATCH for-next 2/4] RDMA/hns: Add IOMMU enable support in hip08
Date: Thu, 9 Nov 2017 09:30:08 +0800 [thread overview]
Message-ID: <5A03AFA0.5090505@huawei.com> (raw)
In-Reply-To: <20171107154838.GC21466@ziepe.ca>
On 2017/11/7 23:48, Jason Gunthorpe wrote:
> On Tue, Nov 07, 2017 at 10:45:29AM +0800, Wei Hu (Xavier) wrote:
>
>> We reconstruct the code as below:
>> It replaces dma_alloc_coherent with __get_free_pages and
>> dma_map_single functions. So, we can vmap serveral ptrs returned by
>> __get_free_pages, right?
> Can't you just use vmalloc and dma_map that? Other drivers follow that
> approach..
>
> However, dma_alloc_coherent and dma_map_single are not the same
> thing. You can't touch the vmap memory once you call dma_map unless
> the driver also includes dma cache flushing calls in all the right
> places.
>
> The difference is that alloc_coherent will return non-cachable memory
> if necessary, while get_free_pages does not.
>
> Jason
Hi, Jason
Thanks for your suggestion.
We will fix it.
Regards
Wei Hu
>
> .
>
next prev parent reply other threads:[~2017-11-09 1:30 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-30 9:28 [PATCH for-next 0/4] Add Features & Code improvements for hip08 Wei Hu (Xavier)
2017-09-30 9:28 ` [PATCH for-next 1/4] RDMA/hns: Support WQE/CQE/PBL page size configurable feature in hip08 Wei Hu (Xavier)
2017-09-30 9:28 ` [PATCH for-next 2/4] RDMA/hns: Add IOMMU enable support " Wei Hu (Xavier)
2017-09-30 16:10 ` Leon Romanovsky
2017-10-12 12:31 ` Wei Hu (Xavier)
2017-10-12 12:59 ` Robin Murphy
2017-11-01 7:46 ` Wei Hu (Xavier)
2017-11-01 12:26 ` Robin Murphy
2017-11-07 2:45 ` Wei Hu (Xavier)
2017-11-07 6:32 ` Leon Romanovsky
2017-11-09 1:17 ` Wei Hu (Xavier)
2017-11-07 15:48 ` Jason Gunthorpe
2017-11-07 15:58 ` Christoph Hellwig
2017-11-07 16:03 ` Jason Gunthorpe
2017-11-09 1:26 ` Wei Hu (Xavier)
2017-11-09 1:30 ` Wei Hu (Xavier) [this message]
2017-11-09 1:36 ` Wei Hu (Xavier)
2017-10-12 14:54 ` Leon Romanovsky
2017-10-18 8:42 ` Wei Hu (Xavier)
2017-10-18 9:12 ` Wei Hu (Xavier)
2017-10-18 14:23 ` Leon Romanovsky
2017-09-30 9:29 ` [PATCH for-next 3/4] RDMA/hns: Update the IRRL table chunk size " Wei Hu (Xavier)
2017-10-01 5:40 ` Leon Romanovsky
2017-10-17 11:40 ` Wei Hu (Xavier)
2017-09-30 9:29 ` [PATCH for-next 4/4] RDMA/hns: Update the PD&CQE&MTT specification " Wei Hu (Xavier)
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