From: "zhichang.yuan" <yuanzhichang@hisilicon.com>
To: Arnd Bergmann <arnd@arndb.de>,
Gabriele Paoloni <gabriele.paoloni@huawei.com>
Cc: "linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"mark.rutland@arm.com" <mark.rutland@arm.com>,
"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
"lorenzo.pieralisi@arm.com" <lorenzo.pieralisi@arm.com>,
"minyard@acm.org" <minyard@acm.org>,
"linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
"benh@kernel.crashing.org" <benh@kernel.crashing.org>,
John Garry <john.garry@huawei.com>,
"will.deacon@arm.com" <will.deacon@arm.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"xuwei (O)" <xuwei5@hisilicon.com>,
Linuxarm <linuxarm@huawei.com>,
"zourongrong@gmail.com" <zourongrong@gmail.com>,
"robh+dt@kernel.org" <robh+dt@kernel.org>,
"kantyzc@163.com" <kantyzc@163.com>,
"linux-serial@vger.kernel.org" <linux-serial@vger.kernel.org>,
"catalin.marinas@arm.com" <catalin.marinas@arm.com>,
"olof@lixom.net" <olof@lixom.net>,
"liviu.dudau@arm.com" <liviu.dudau@arm.com>,
"bhelgaas@googl e.com" <bhelgaas@google.com>,
"zhichang.yuan02@gmail.com" <zhichang.yuan02@gmail.com>
Subject: Re: [PATCH V5 3/3] ARM64 LPC: LPC driver implementation on Hip06
Date: Fri, 11 Nov 2016 18:09:49 +0800 [thread overview]
Message-ID: <582598ED.6080803@hisilicon.com> (raw)
In-Reply-To: <10334260.ztLXZ2Oynd@wuerfel>
Hi, Arnd,
On 2016/11/11 0:07, Arnd Bergmann wrote:
> On Thursday, November 10, 2016 3:36:49 PM CET Gabriele Paoloni wrote:
>>
>> Where should we get the range from? For LPC we know that it is going
>> Work on anything that is not used by PCI I/O space, and this is
>> why we use [0, PCIBIOS_MIN_IO]
>
> It should be allocated the same way we allocate PCI config space
> segments. This is currently done with the io_range list in
> drivers/pci/pci.c, which isn't perfect but could be extended
> if necessary. Based on what others commented here, I'd rather
> make the differences between ISA/LPC and PCI I/O ranges smaller
> than larger.
>
>>> Your current version has
>>>
>>> if (arm64_extio_ops->pfout) \
>>> arm64_extio_ops->pfout(arm64_extio_ops->devpara,\
>>> addr, value, sizeof(type)); \
>>>
>>> Instead, just subtract the start of the range from the logical
>>> port number to transform it back into a bus-local port number:
>>
>> These accessors do not operate on IO tokens:
>>
>> If (arm64_extio_ops->start > addr || arm64_extio_ops->end < addr)
>> addr is not going to be an I/O token; in fact patch 2/3 imposes that
>> the I/O tokens will start at PCIBIOS_MIN_IO. So from 0 to PCIBIOS_MIN_IO
>> we have free physical addresses that the accessors can operate on.
>
> Ah, I missed that part. I'd rather not use PCIBIOS_MIN_IO to refer to
> the logical I/O tokens, the purpose of that macro is really meant
> for allocating PCI I/O port numbers within the address space of
> one bus.
>
> Note that it's equally likely that whichever next platform needs
> non-mapped I/O access like this actually needs them for PCI I/O space,
> and that will use it on addresses registered to a PCI host bridge.
>
> If we separate the two steps:
>
> a) assign a range of logical I/O port numbers to a bus
> b) register a set of helpers for redirecting logical I/O
> port to a helper function
>
It seems that we need to add a new bus and the corresponding resource management
which can also cover current PCI pio mapping, is it right?
Thanks,
Zhichang
> then I think the code will get cleaner and more flexible.
> It should actually then be able to replace the powerpc
> specific implementation.
>
> Arnd
>
> .
>
next prev parent reply other threads:[~2016-11-11 10:10 UTC|newest]
Thread overview: 83+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-08 3:47 [PATCH V5 0/3] ARM64 LPC: legacy ISA I/O support zhichang.yuan
2016-11-08 3:47 ` [PATCH V5 1/3] ARM64 LPC: Indirect ISA port IO introduced zhichang.yuan
2016-11-08 12:03 ` Mark Rutland
2016-11-08 16:09 ` Arnd Bergmann
2016-11-08 16:15 ` Arnd Bergmann
2016-11-08 23:16 ` Benjamin Herrenschmidt
2016-11-10 8:33 ` zhichang.yuan
2016-11-10 11:22 ` Mark Rutland
2016-11-10 19:32 ` Benjamin Herrenschmidt
2016-11-11 10:07 ` zhichang.yuan
2016-11-18 9:20 ` Arnd Bergmann
2016-11-18 11:12 ` zhichang.yuan
2016-11-18 11:38 ` Arnd Bergmann
2016-11-21 12:58 ` John Garry
2016-11-08 16:12 ` Will Deacon
2016-11-08 16:33 ` John Garry
2016-11-08 16:49 ` Will Deacon
2016-11-08 17:05 ` John Garry
2016-11-08 22:35 ` Arnd Bergmann
2016-11-09 11:29 ` John Garry
2016-11-09 21:33 ` Arnd Bergmann
2016-12-22 8:15 ` Ming Lei
2016-12-23 1:43 ` zhichang.yuan
2016-12-23 7:24 ` Ming Lei
2017-01-06 11:43 ` Arnd Bergmann
2016-11-08 3:47 ` [PATCH V5 2/3] ARM64 LPC: Add missing range exception for special ISA zhichang.yuan
2016-11-08 5:17 ` kbuild test robot
2016-11-08 5:27 ` kbuild test robot
2016-11-08 11:49 ` Mark Rutland
2016-11-08 16:19 ` Arnd Bergmann
2016-11-08 17:10 ` Mark Rutland
2016-11-09 13:54 ` One Thousand Gnomes
2016-11-09 14:51 ` Gabriele Paoloni
2016-11-09 21:38 ` Arnd Bergmann
2016-11-14 11:11 ` One Thousand Gnomes
2016-11-18 9:22 ` Arnd Bergmann
2016-11-08 23:12 ` Benjamin Herrenschmidt
2016-11-09 11:20 ` Mark Rutland
2016-11-10 7:08 ` Benjamin Herrenschmidt
2016-11-09 11:39 ` liviu.dudau
2016-11-09 16:16 ` Gabriele Paoloni
2016-11-09 16:50 ` liviu.dudau
2016-11-10 6:24 ` zhichang.yuan
2016-11-10 16:06 ` Gabriele Paoloni
2016-11-11 10:37 ` liviu.dudau
2016-11-08 3:47 ` [PATCH V5 3/3] ARM64 LPC: LPC driver implementation on Hip06 zhichang.yuan
2016-11-08 6:11 ` kbuild test robot
2016-11-08 16:24 ` Arnd Bergmann
2016-11-09 12:10 ` Gabriele Paoloni
2016-11-09 21:34 ` Arnd Bergmann
2016-11-10 6:40 ` zhichang.yuan
2016-11-10 9:12 ` Arnd Bergmann
2016-11-10 12:36 ` zhichang.yuan
2016-11-18 11:46 ` Arnd Bergmann
2016-11-10 15:36 ` Gabriele Paoloni
2016-11-10 16:07 ` Arnd Bergmann
2016-11-11 10:09 ` zhichang.yuan [this message]
2016-11-11 10:48 ` liviu.dudau
2016-11-11 13:39 ` Gabriele Paoloni
2016-11-11 14:45 ` liviu.dudau
2016-11-11 15:53 ` Gabriele Paoloni
2016-11-11 18:16 ` liviu.dudau
2016-11-14 8:26 ` Gabriele Paoloni
2016-11-14 11:26 ` liviu.dudau
2016-11-18 10:17 ` Arnd Bergmann
2016-11-18 12:07 ` Gabriele Paoloni
2016-11-18 12:24 ` Arnd Bergmann
2016-11-18 12:53 ` Gabriele Paoloni
2016-11-18 13:42 ` Arnd Bergmann
2016-11-18 16:18 ` Gabriele Paoloni
2016-11-18 16:34 ` Arnd Bergmann
2016-11-18 17:03 ` Gabriele Paoloni
2016-11-23 14:16 ` Arnd Bergmann
2016-11-23 15:22 ` Gabriele Paoloni
2016-11-23 17:07 ` Arnd Bergmann
2016-11-23 23:23 ` Arnd Bergmann
2016-11-24 9:12 ` zhichang.yuan
2016-11-24 10:24 ` Arnd Bergmann
2016-11-25 8:46 ` Gabriele Paoloni
2016-11-25 12:03 ` Arnd Bergmann
2016-11-25 16:27 ` Gabriele Paoloni
2016-11-11 16:54 ` zhichang.yuan
2016-11-14 11:06 ` One Thousand Gnomes
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