From: tfiga@chromium.org (Tomasz Figa)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 2/5] iommu/mediatek: Add mt8173 IOMMU driver
Date: Tue, 10 Mar 2015 02:00:44 +0900 [thread overview]
Message-ID: <CAAFQd5DpXxyoNiTGC4YYnpXeKo43XXrC+my6KWOV1pGq1jw6Aw@mail.gmail.com> (raw)
In-Reply-To: <1425912389.4871.19.camel@mtksdaap41>
On Mon, Mar 9, 2015 at 11:46 PM, Yingjoe Chen <yingjoe.chen@mediatek.com> wrote:
> On Mon, 2015-03-09 at 20:11 +0900, Tomasz Figa wrote:
> <...>
>> > +/*
>> > + * pimudev is a global var for dma_alloc_coherent.
>> > + * It is not accepatable, we will delete it if "domain_alloc" is enabled
>> > + */
>> > +static struct device *pimudev;
>>
>> This is indeed not acceptable. Could you replace dma_alloc_coherent()
>> with something that doesn't require device pointer, e.g.
>> alloc_pages()? (Although that would require you to handle cache
>> maintenance in the driver, due to cached memory allocated.) I need to
>> think about a better solution for this.
>
> Hi,
>
> For 2nd level page table, we use cached memory now. Currently we are
> using __dma_flush_range to flush the cache, which is also unacceptable.
>
> For proper cache management, we'll need to use dma_map_single or
> dma_sync_*, which still need a deivce*.
Looking at how already mainlined drivers do this, they either use
dmac_flush_range()
(https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/drivers/iommu/msm_iommu.c?id=refs/tags/v4.0-rc3#n80)
or directly __cpuc_flush_dcache_area() and outer_flush_range()
(https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/drivers/iommu/rockchip-iommu.c?id=refs/tags/v4.0-rc3#n93).
Joerg, what's your opinion on this?
Best regards,
Tomasz
next prev parent reply other threads:[~2015-03-09 17:00 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-06 10:48 [RFC PATCH 0/5] MT8173 IOMMU support yong.wu at mediatek.com
2015-03-06 10:48 ` [PATCH 1/5] soc: mediatek: Add SMI driver yong.wu at mediatek.com
2015-03-06 11:30 ` Paul Bolle
2015-03-09 11:57 ` Yong Wu
2015-03-09 17:59 ` Paul Bolle
2015-03-09 21:54 ` Arnd Bergmann
2015-03-10 6:17 ` Yingjoe Chen
2015-03-09 3:26 ` Yingjoe Chen
2015-03-09 21:56 ` Arnd Bergmann
2015-03-10 6:27 ` Yingjoe Chen
2015-03-10 9:05 ` Arnd Bergmann
2015-03-10 9:24 ` Lucas Stach
2015-03-09 11:03 ` Sascha Hauer
2015-03-06 10:48 ` [PATCH 2/5] iommu/mediatek: Add mt8173 IOMMU driver yong.wu at mediatek.com
2015-03-06 10:58 ` Will Deacon
2015-03-09 12:11 ` Yong Wu
2015-03-17 15:14 ` Will Deacon
2015-03-06 17:15 ` Mitchel Humpherys
2015-03-09 12:16 ` Yong Wu
2015-03-09 16:57 ` Mitchel Humpherys
2015-03-08 4:12 ` Tomasz Figa
2015-03-12 14:16 ` Yong Wu
2015-03-09 8:24 ` Daniel Kurtz
2015-03-09 11:11 ` Tomasz Figa
2015-03-09 14:46 ` Yingjoe Chen
2015-03-09 17:00 ` Tomasz Figa [this message]
2015-03-10 3:41 ` Yingjoe Chen
2015-03-10 4:06 ` Tomasz Figa
2015-03-11 10:53 ` Tomasz Figa
2015-03-18 11:22 ` Yong Wu
2015-03-20 19:14 ` Robin Murphy
2015-04-14 6:50 ` Yong Wu
2015-03-27 9:41 ` Tomasz Figa
2015-04-14 6:31 ` Yong Wu
2015-04-15 2:20 ` Tomasz Figa
2015-04-15 7:06 ` Yong Wu
2015-04-15 7:41 ` Tomasz Figa
2015-04-29 6:23 ` Yong Wu
2015-03-06 10:48 ` [PATCH 3/5] dt-bindings: mediatek: Add smi dts binding yong.wu at mediatek.com
2015-03-06 11:13 ` Mark Rutland
2015-03-09 12:55 ` Yong Wu
2015-04-14 9:07 ` Yong Wu
2015-04-14 10:06 ` Mark Rutland
2015-04-14 13:49 ` Yong Wu
2015-04-14 13:55 ` Yong Wu
2015-04-14 13:56 ` Mark Rutland
2015-03-06 14:48 ` Sergei Shtylyov
2015-03-09 12:32 ` Yong Wu
2015-03-06 10:48 ` [PATCH 4/5] dt-bindings: iommu: Add binding for mediatek IOMMU yong.wu at mediatek.com
2015-03-06 11:21 ` Mark Rutland
2015-03-09 11:30 ` Yong Wu
2015-03-06 10:48 ` [PATCH 5/5] dts: mt8173: Add iommu/smi nodes for mt8173 yong.wu at mediatek.com
2015-03-07 15:20 ` Daniel Kurtz
2015-03-09 12:18 ` Yong Wu
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