From: kishon@ti•com (Kishon Vijay Abraham I)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v6] PCI: Store PCIe bus address in struct of_pci_range
Date: Fri, 31 Jul 2015 20:27:10 +0530 [thread overview]
Message-ID: <55BB8CC6.1080203@ti.com> (raw)
In-Reply-To: <EE11001F9E5DDD47B7634E2F8A612F2E01D70589@lhreml503-mbs>
+Arnd
Hi,
On Friday 31 July 2015 07:55 PM, Gabriele Paoloni wrote:
> [+cc Kishon]
>
>> -----Original Message-----
>> From: linux-pci-owner at vger.kernel.org [mailto:linux-pci-
>> owner at vger.kernel.org] On Behalf Of Rob Herring
>> Sent: Thursday, July 30, 2015 9:42 PM
>> To: Gabriele Paoloni
>> Cc: Bjorn Helgaas; arnd at arndb.de; lorenzo.pieralisi at arm.com; Wangzhou
>> (B); robh+dt at kernel.org; james.morse at arm.com; Liviu.Dudau at arm.com;
>> linux-pci at vger.kernel.org; linux-arm-kernel at lists.infradead.org;
>> devicetree at vger.kernel.org; Yuanzhichang; Zhudacai; zhangjukuo;
>> qiuzhenfa; Liguozhu (Kenneth); Jingoo Han; Pratyush Anand
>> Subject: Re: [PATCH v6] PCI: Store PCIe bus address in struct
>> of_pci_range
>>
>> On Thu, Jul 30, 2015 at 12:34 PM, Gabriele Paoloni
>> <gabriele.paoloni@huawei•com> wrote:
>>>> -----Original Message-----
>>>> From: Bjorn Helgaas [mailto:bhelgaas at google.com]
>>>> Sent: 30 July 2015 18:15
>>>> On Thu, Jul 30, 2015 at 04:50:55PM +0000, Gabriele Paoloni wrote:
>>>>>> -----Original Message-----
>>>>>> From: linux-pci-owner at vger.kernel.org [mailto:linux-pci-
>>>>>> owner at vger.kernel.org] On Behalf Of Bjorn Helgaas
>>>>>> Sent: Thursday, July 30, 2015 5:15 PM
>>>>>> On Thu, Jul 30, 2015 at 01:52:13PM +0000, Gabriele Paoloni wrote:
>>
>> [...]
>>
>>>>>>> I don?t think we should rely on [CPU] addresses...what if the
>>>>>> intermediate
>>>>>>> translation layer changes the lower significant bits of the
>> "bus
>>>>>> address"
>>>>>>> to translate into a cpu address?
>>>>>>
>>>>>> Is it really a possiblity that the lower bits could be changed?
>>>>>
>>>>> I've checked all the current deignware users DTs except "pci-
>>>> layerscape"
>>>>> that I could not find:
>>>>> spear1310.dtsi
>>>>> spear1340.dtsi
>>>>> dra7.dtsi
>>>>> imx6qdl.dtsi
>>>>> imx6sx.dtsi
>>>>> keystone.dtsi
>>>>> exynos5440.dtsi
>>>>>
>>>>> None of them modifies the lower bits. To be more precise the only
>> guy
>>>>> that provides another translation layer is "dra7.dtsi":
>>>>> axi0
>>>>> http://lxr.free-
>> electrons.com/source/arch/arm/boot/dts/dra7.dtsi#L207
>>>>>
>>>>> axi1
>>>>> http://lxr.free-
>> electrons.com/source/arch/arm/boot/dts/dra7.dtsi#L241
>>>>>
>>>>> For this case masking the top 4bits (bits28 to 31) should make the
>> job.
>>
>> IMO, we should just fix this case. After further study, I don't think
>> this is a DW issue, but rather an SOC integration issue.
>>
>> I believe you can just fixup the address in the pp->ops->host_init hook.
>>
>
> Yes I guess that I could just assign pp->(*)_mod_base to the CPU address
> in DW and mask it out in dra7xx_pcie_host_init()...
>
> Kishon, would you be ok with that?
Initially I was using *base-mask* property from dt. Me and Arnd (cc'ed) had
this discussion [1] before we decided the current approach. It'll be good to
check with Arnd too.
[1] -> http://lists.infradead.org/pipermail/linux-arm-kernel/2014-May/253528.html
Thanks
Kishon
next prev parent reply other threads:[~2015-07-31 14:57 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-27 15:17 [PATCH v6] PCI: Store PCIe bus address in struct of_pci_range Gabriele Paoloni
2015-07-29 16:04 ` Gabriele Paoloni
2015-07-29 17:20 ` Bjorn Helgaas
2015-07-29 19:44 ` Gabriele Paoloni
2015-07-29 21:47 ` Bjorn Helgaas
2015-07-30 8:30 ` Gabriele Paoloni
2015-07-30 11:20 ` Liviu Dudau
2015-07-30 7:16 ` Zhou Wang
2015-07-30 13:42 ` Rob Herring
2015-07-30 13:52 ` Gabriele Paoloni
2015-07-30 14:15 ` Gabriele Paoloni
2015-07-30 16:14 ` Bjorn Helgaas
2015-07-30 16:50 ` Gabriele Paoloni
2015-07-30 17:14 ` Bjorn Helgaas
2015-07-30 17:34 ` Gabriele Paoloni
2015-07-30 20:41 ` Rob Herring
2015-07-31 14:25 ` Gabriele Paoloni
2015-07-31 14:57 ` Kishon Vijay Abraham I [this message]
2015-07-31 15:09 ` Gabriele Paoloni
2015-08-03 14:41 ` Jingoo Han
2015-07-31 16:53 ` Rob Herring
2015-08-03 11:18 ` Gabriele Paoloni
2015-08-04 4:19 ` Jingoo Han
2015-08-04 10:12 ` Gabriele Paoloni
2015-08-06 13:52 ` Gabriele Paoloni
2015-08-06 15:06 ` Jingoo Han
2015-08-07 5:46 ` Zhou Wang
2015-07-30 16:06 ` Bjorn Helgaas
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