From: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
To: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Cc: "linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
Liviu Dudau <Liviu.Dudau@arm.com>,
Krzysztof Halasa <khalasa@piap.pl>, Arnd Bergmann <arnd@arndb.de>,
Phil Edworthy <phil.edworthy@renesas.com>,
Jingoo Han <jg1.han@samsung.com>,
Bjorn Helgaas <bhelgaas@google.com>,
Russell King <linux@arm.linux.org.uk>,
Mohit Kumar <mohit.kumar@st.com>
Subject: Re: [RFC PATCH 0/2] arm: pcibios: remove pci_sys_data domain
Date: Thu, 30 Oct 2014 16:52:46 +0000 [thread overview]
Message-ID: <20141030165246.GC2048@red-moon> (raw)
In-Reply-To: <20141030162552.GC26820@obsidianresearch.com>
[Dropped Anton, his email address bounces]
On Thu, Oct 30, 2014 at 04:25:52PM +0000, Jason Gunthorpe wrote:
> On Thu, Oct 30, 2014 at 11:44:46AM +0000, Lorenzo Pieralisi wrote:
>
> > Code in drivers/pci/pci-mvebu.c has been changed to add a domain
> > number to PCI resources by using the nr value coming from the setup
> > pcibios32 callback, which may not be correct and should be considered
> > a temporary solution waiting for review comments.
>
> The intent of the string was to have the domain number so that
> resources in /proc/iomem can be correlated with lspci.
>
> This would be a 'best practice' - all PCI drivers need to request
> resource, and the resource should be relatable back to the PCI
> domain... So it would be best if the domain number was available at
> this point in a driver's flow.
It is not available with the new approach and the generic PCI domains since
the set-up hook is called before creating the pci_bus. That's why
I mentioned that in the cover letter, and that's good it caught your
attention.
On a side note, when the resources are parsed from DT ranges, ie in:
of_pci_get_host_bridge_resources()
the resources won't contain the domain number you are looking for here, for
the records, so we'd better find an agreement sooner rather than later.
> > - snprintf(pcie->mem_name, sizeof(pcie->mem_name), "PCI MEM %04x",
> > - domain);
> > + snprintf(pcie->mem_name, sizeof(pcie->mem_name), "PCI MEM %04x", nr);
>
> I'm not sure what 'nr' is in this context, if it is not the domain
> number then I'd just drop the 0x04x entirely rather than include
> some nonsense number...
nr is the index (0 to nr_controllers) in struct hw_pci of the controller
being set-up. For this driver it is always 0, and BTW, sys->domain was 0 too
and I do not see any code that can change its value to anything other
than 0, at least in the mainline kernel.
So basically I could go as far as sticking 0000 to the string given the
current code. I did not drop the 0x04x entirely since I do not want to break
userspace, I was tempted though, let me know if I am allowed to do that.
Thanks,
Lorenzo
next prev parent reply other threads:[~2014-10-30 16:52 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-30 11:44 [RFC PATCH 0/2] arm: pcibios: remove pci_sys_data domain Lorenzo Pieralisi
2014-10-30 11:44 ` [RFC PATCH 1/2] arm: cns3xxx: pci: remove artificial dependency on " Lorenzo Pieralisi
2014-11-01 12:32 ` Michał Mirosław
2014-11-03 10:09 ` Arnd Bergmann
2014-10-30 11:44 ` [RFC PATCH 2/2] arm: pcibios: move to generic PCI domains Lorenzo Pieralisi
2014-10-30 11:55 ` Arnd Bergmann
2014-10-30 16:20 ` Lorenzo Pieralisi
2014-10-30 12:27 ` Yijing Wang
2014-10-30 16:21 ` Lorenzo Pieralisi
2014-10-31 13:43 ` Phil Edworthy
2014-10-31 16:37 ` Bjorn Helgaas
2014-10-31 17:04 ` Phil Edworthy
2014-11-03 23:26 ` Simon Horman
2014-11-04 11:44 ` Liviu Dudau
2014-11-03 11:06 ` Lorenzo Pieralisi
2014-11-03 1:18 ` Jingoo Han
2014-11-03 2:36 ` Karicheri, Muralidharan
2014-11-03 11:23 ` Lorenzo Pieralisi
2014-11-03 11:33 ` Lucas Stach
2014-11-03 12:13 ` Jingoo Han
2014-11-03 3:48 ` Yijing Wang
2014-11-03 10:49 ` Lorenzo Pieralisi
2014-10-30 16:25 ` [RFC PATCH 0/2] arm: pcibios: remove pci_sys_data domain Jason Gunthorpe
2014-10-30 16:52 ` Lorenzo Pieralisi [this message]
2014-10-30 17:03 ` Jason Gunthorpe
2014-10-30 17:39 ` Liviu Dudau
2014-10-30 17:45 ` Jason Gunthorpe
2014-10-30 18:09 ` Lorenzo Pieralisi
2014-10-30 18:42 ` Jason Gunthorpe
2014-10-30 19:21 ` Arnd Bergmann
2014-10-30 19:35 ` Jason Gunthorpe
2014-10-30 20:03 ` Arnd Bergmann
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=20141030165246.GC2048@red-moon \
--to=lorenzo.pieralisi@arm.com \
--cc=Liviu.Dudau@arm.com \
--cc=arnd@arndb.de \
--cc=bhelgaas@google.com \
--cc=jg1.han@samsung.com \
--cc=jgunthorpe@obsidianresearch.com \
--cc=khalasa@piap.pl \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-pci@vger.kernel.org \
--cc=linux@arm.linux.org.uk \
--cc=mohit.kumar@st.com \
--cc=phil.edworthy@renesas.com \
/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).