devicetree.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Benjamin Herrenschmidt <benh-XVmvHMARGAS8U2dJNN8I7kB+6BGkLq7r@public.gmane.org>
To: Mark Rutland <mark.rutland-5wv7dgnIgG8@public.gmane.org>,
	"zhichang.yuan"
	<yuanzhichang-C8/M+/jPZTeaMJb+Lgu22Q@public.gmane.org>
Cc: catalin.marinas-5wv7dgnIgG8@public.gmane.org,
	will.deacon-5wv7dgnIgG8@public.gmane.org,
	robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org,
	bhelgaas-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org,
	olof-nZhT3qVonbNeoWH0uzbU5w@public.gmane.org,
	arnd-r2nGTMty4D4@public.gmane.org,
	linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
	lorenzo.pieralisi-5wv7dgnIgG8@public.gmane.org,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linuxarm-hv44wF8Li93QT0dZR+AlfA@public.gmane.org,
	devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linux-pci-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linux-serial-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	minyard-HInyCGIudOg@public.gmane.org,
	liviu.dudau-5wv7dgnIgG8@public.gmane.org,
	zourongrong-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org,
	john.garry-hv44wF8Li93QT0dZR+AlfA@public.gmane.org,
	gabriele.paoloni-hv44wF8Li93QT0dZR+AlfA@public.gmane.org,
	zhichang.yuan02-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org,
	kantyzc-9Onoh4P/yGk@public.gmane.org,
	xuwei5-C8/M+/jPZTeaMJb+Lgu22Q@public.gmane.org,
	marc.zyngier-5wv7dgnIgG8@public.gmane.org
Subject: Re: [PATCH V5 2/3] ARM64 LPC: Add missing range exception for special ISA
Date: Wed, 09 Nov 2016 10:12:59 +1100	[thread overview]
Message-ID: <1478646779.7430.66.camel@kernel.crashing.org> (raw)
In-Reply-To: <20161108114953.GB15297@leverpostej>

On Tue, 2016-11-08 at 11:49 +0000, Mark Rutland wrote:
> 
> My understanding of ISA (which may be flawed) is that it's not part of
> the PCI host bridge, but rather on x86 it happens to share the IO space
> with PCI.

Sort-of. On some systems it actually goes through PCI and there's a
PCI->ISA bridge that uses substractive decoding to the legacy devices.

> So, how about this becomes:
> 
>   Hisilicon Hip06 SoCs implement a Low Pin Count (LPC) controller, which
>   provides access to some legacy ISA devices.
> 
> I believe that we could theoretically have multiple independent LPC/ISA
> busses, as is possible with PCI on !x86 systems. If the current ISA code
> assumes a singleton bus, I think that's something that needs to be fixed
> up more generically.
> 
> I don't see why we should need any architecture-specific code here. Why
> can we not fix up the ISA bus code in drivers/of/address.c such that it
> handles multiple ISA bus instances, and translates all sub-device
> addresses relative to the specific bus instance?

What in that code prevents that today ?

Cheers,
Ben.

--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

  parent reply	other threads:[~2016-11-08 23:12 UTC|newest]

Thread overview: 84+ 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
     [not found] ` <1478576829-112707-1-git-send-email-yuanzhichang-C8/M+/jPZTeaMJb+Lgu22Q@public.gmane.org>
2016-11-08  3:47   ` [PATCH V5 1/3] ARM64 LPC: Indirect ISA port IO introduced zhichang.yuan
     [not found]     ` <1478576829-112707-2-git-send-email-yuanzhichang-C8/M+/jPZTeaMJb+Lgu22Q@public.gmane.org>
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
2017-01-07  1:25         ` 答复: " Yuanzhichang
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
     [not found]   ` <1478576829-112707-3-git-send-email-yuanzhichang-C8/M+/jPZTeaMJb+Lgu22Q@public.gmane.org>
2016-11-08  5:27     ` kbuild test robot
2016-11-09 11:39     ` liviu.dudau-5wv7dgnIgG8
2016-11-09 16:16       ` Gabriele Paoloni
2016-11-09 16:50         ` liviu.dudau-5wv7dgnIgG8
2016-11-10  6:24           ` zhichang.yuan
     [not found]           ` <20161109165044.GE10219-2JSQmVVBSi7ZROr8t4l/smS4ubULX0JqMm0uRHvK7Nw@public.gmane.org>
2016-11-10 16:06             ` Gabriele Paoloni
2016-11-11 10:37               ` liviu.dudau
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
     [not found]         ` <20161109135453.2e5402bd-qBU/x9rampVanCEyBjwyrvXRex20P6io@public.gmane.org>
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 [this message]
2016-11-09 11:20       ` Mark Rutland
2016-11-10  7:08         ` Benjamin Herrenschmidt
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
2016-11-11 10:48                 ` liviu.dudau
2016-11-11 13:39                 ` Gabriele Paoloni
2016-11-11 14:45                   ` liviu.dudau-5wv7dgnIgG8
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
     [not found]                             ` <20161114112625.GO10219-2JSQmVVBSi7ZROr8t4l/smS4ubULX0JqMm0uRHvK7Nw@public.gmane.org>
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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1478646779.7430.66.camel@kernel.crashing.org \
    --to=benh-xvmvhmargas8u2djnn8i7kb+6bgklq7r@public.gmane.org \
    --cc=arnd-r2nGTMty4D4@public.gmane.org \
    --cc=bhelgaas-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org \
    --cc=catalin.marinas-5wv7dgnIgG8@public.gmane.org \
    --cc=devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
    --cc=gabriele.paoloni-hv44wF8Li93QT0dZR+AlfA@public.gmane.org \
    --cc=john.garry-hv44wF8Li93QT0dZR+AlfA@public.gmane.org \
    --cc=kantyzc-9Onoh4P/yGk@public.gmane.org \
    --cc=linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org \
    --cc=linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
    --cc=linux-pci-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
    --cc=linux-serial-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
    --cc=linuxarm-hv44wF8Li93QT0dZR+AlfA@public.gmane.org \
    --cc=liviu.dudau-5wv7dgnIgG8@public.gmane.org \
    --cc=lorenzo.pieralisi-5wv7dgnIgG8@public.gmane.org \
    --cc=marc.zyngier-5wv7dgnIgG8@public.gmane.org \
    --cc=mark.rutland-5wv7dgnIgG8@public.gmane.org \
    --cc=minyard-HInyCGIudOg@public.gmane.org \
    --cc=olof-nZhT3qVonbNeoWH0uzbU5w@public.gmane.org \
    --cc=robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org \
    --cc=will.deacon-5wv7dgnIgG8@public.gmane.org \
    --cc=xuwei5-C8/M+/jPZTeaMJb+Lgu22Q@public.gmane.org \
    --cc=yuanzhichang-C8/M+/jPZTeaMJb+Lgu22Q@public.gmane.org \
    --cc=zhichang.yuan02-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org \
    --cc=zourongrong-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).