From: Liviu Dudau <Liviu.Dudau@arm.com>
To: Rob Herring <robherring2@gmail.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>,
Arnd Bergmann <arnd@arndb.de>, Rob Herring <robh+dt@kernel.org>,
Jason Gunthorpe <jgunthorpe@obsidianresearch.com>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Catalin Marinas <Catalin.Marinas@arm.com>,
Will Deacon <Will.Deacon@arm.com>,
Russell King <linux@arm.linux.org.uk>,
linux-pci <linux-pci@vger.kernel.org>,
Linus Walleij <linus.walleij@linaro.org>,
Tanmay Inamdar <tinamdar@apm.com>,
Grant Likely <grant.likely@secretlab.ca>,
Sinan Kaya <okaya@codeaurora.org>,
Jingoo Han <jg1.han@samsung.com>,
Kukjin Kim <kgene.kim@samsung.com>,
Suravee Suthikulanit <suravee.suthikulpanit@amd.com>,
linux-arch <linux-arch@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Device Tree ML <devicetree@vger.kernel.org>,
LAKML <linux-arm-kernel@lists.infradead.org>,
"grant.likely@linaro.org" <grant.likely@linaro.org>
Subject: Re: [PATCH v12 08/12] PCI: OF: Introduce helper function for retrieving PCI domain numbers
Date: Fri, 26 Sep 2014 23:47:52 +0100 [thread overview]
Message-ID: <20140926224752.GB22030@e106497-lin.cambridge.arm.com> (raw)
In-Reply-To: <CAL_JsqKJ6bfPuOofo4grVm3qW_WOpUzcS1juZvHxZdFyyF_19A@mail.gmail.com>
On Fri, Sep 26, 2014 at 10:53:26PM +0100, Rob Herring wrote:
> On Fri, Sep 26, 2014 at 4:20 PM, <liviu@dudau.co.uk> wrote:
> > On Fri, Sep 26, 2014 at 01:20:39PM -0500, Rob Herring wrote:
> >> On Tue, Sep 23, 2014 at 2:01 PM, Liviu Dudau <Liviu.Dudau@arm.com> wrote:
> >> > Add pci_get_new_domain_nr() to allocate a new domain number
> >> > and of_get_pci_domain_nr() to retrieve the PCI domain number
> >> > of a given device from DT. Host bridge drivers or architecture
> >> > specific code can choose to implement their PCI domain number
> >> > policy using these two functions.
> >> >
> >> > Using of_get_pci_domain_nr() guarantees a stable PCI domain
> >> > number on every boot provided that all host bridge controllers
> >> > are assigned a number in the device tree using "linux,pci-domain"
> >> > property. Mix use of pci_get_new_domain_nr() and of_get_pci_domain_nr()
> >> > is not recommended as it can lead to potentially conflicting
> >> > domain numbers being assigned to root busses behind different
> >> > host bridges.
> >> >
> >> > Cc: Bjorn Helgaas <bhelgaas@google.com>
> >> > Cc: Arnd Bergmann <arnd@arndb.de>
> >> > Cc: Grant Likely <grant.likely@linaro.org>
> >> > Cc: Rob Herring <robh+dt@kernel.org>
> >> > Cc: Catalin Marinas <catalin.marinas@arm.com>
> >> > Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
> >>
> >> Looks pretty good, but a couple of comments that can be addressed as
> >> follow-up patches.
> >>
> >> > ---
> >> > drivers/of/of_pci.c | 25 +++++++++++++++++++++++++
> >> > drivers/pci/pci.c | 9 +++++++++
> >> > include/linux/of_pci.h | 7 +++++++
> >> > include/linux/pci.h | 3 +++
> >> > 4 files changed, 44 insertions(+)
> >> >
> >> > diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c
> >> > index 8481996..82d172f 100644
> >> > --- a/drivers/of/of_pci.c
> >> > +++ b/drivers/of/of_pci.c
> >> > @@ -89,6 +89,31 @@ int of_pci_parse_bus_range(struct device_node *node, struct resource *res)
> >> > }
> >> > EXPORT_SYMBOL_GPL(of_pci_parse_bus_range);
> >> >
> >> > +/**
> >> > + * This function will try to obtain the host bridge domain number by
> >> > + * finding a property called "linux,pci-domain" of the given device node.
> >> > + *
> >> > + * @node: device tree node with the domain information
> >> > + *
> >> > + * Returns the associated domain number from DT in the range [0-0xffff], or
> >> > + * a negative value if the required property is not found.
> >> > + */
> >> > +int of_get_pci_domain_nr(struct device_node *node)
> >> > +{
> >> > + const __be32 *value;
> >> > + int len;
> >> > + u16 domain;
> >> > +
> >> > + value = of_get_property(node, "linux,pci-domain", &len);
> >>
> >> This needs to be documented.
> >
> > I would say needs agreed on *and* documented.
>
> I thought Bjorn already applied the series. Who's agreement are you
> waiting for specifically.
Looks like he only applied about 60% of the series.
I'm not waiting on anyones specifig agreement, just general agreement.
Jason Gunthrope have initially suggested using pci-domain alias which
you don't like, now I'm using "linux,pci-domain" property which you've
ACKed, I wonder if I need to give people more time to catch up to the
fact?
>
> >>
> >> > + if (!value || len < sizeof(*value))
> >> > + return -EINVAL;
> >> > +
> >> > + domain = (u16)be32_to_cpup(value);
> >>
> >> of_property_read_u32 would not work here?
> >
> > It should, I guess, but I want to limit the domain number range to 16 bits.
>
> Okay, but it would still be fewer lines to use of_property_read_u32
> and then cast it. You could use the u16 variant and make the property
> be defined to be 16-bit in the documentation.
True. Will do.
Best regards,
Liviu
>
> Rob
>
--
====================
| I would like to |
| fix the world, |
| but they're not |
| giving me the |
\ source code! /
---------------
¯\_(ツ)_/¯
next prev parent reply other threads:[~2014-09-26 22:47 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-23 19:01 [PATCH v12 00/12] Support for creating generic PCI host bridges from DT Liviu Dudau
2014-09-23 19:01 ` [PATCH v12 01/12] Fix ioport_map() for !CONFIG_GENERIC_IOMAP cases Liviu Dudau
2014-09-23 19:01 ` [PATCH v12 02/12] PCI: Introduce helper functions to deal with PCI I/O ranges Liviu Dudau
2014-09-23 19:01 ` [PATCH v12 03/12] ARM: Define PCI_IOBASE as the base of virtual PCI IO space Liviu Dudau
2014-09-23 19:01 ` [PATCH v12 04/12] PCI: OF: Move of_pci_range_to_resources() into address.c Liviu Dudau
2014-09-23 19:01 ` [PATCH v12 05/12] PCI: OF: Fix the conversion of IO ranges into IO resources Liviu Dudau
2014-09-24 0:22 ` Bjorn Helgaas
2014-09-24 1:12 ` Liviu Dudau
2014-09-24 1:16 ` Bjorn Helgaas
2014-09-24 9:20 ` Robert Richter
2014-09-24 10:14 ` Andrew Murray
2014-09-23 19:01 ` [PATCH v12 06/12] PCI: Create pci_host_bridge before its associated bus in pci_create_root_bus Liviu Dudau
2014-09-25 18:15 ` Yinghai Lu
2014-09-25 19:59 ` Bjorn Helgaas
2014-09-26 14:58 ` Liviu Dudau
2014-09-26 16:17 ` Bjorn Helgaas
2014-09-23 19:01 ` [PATCH v12 07/12] PCI: Introduce generic domain handling for PCI busses Liviu Dudau
2014-09-23 19:01 ` [PATCH v12 08/12] PCI: OF: Introduce helper function for retrieving PCI domain numbers Liviu Dudau
2014-09-26 18:20 ` Rob Herring
2014-09-26 21:20 ` liviu
2014-09-26 21:53 ` Rob Herring
2014-09-26 22:47 ` Liviu Dudau [this message]
2014-09-27 20:18 ` Bjorn Helgaas
2014-09-23 19:01 ` [PATCH v12 09/12] OF: PCI: Add support for parsing PCI host bridge resources from DT Liviu Dudau
2014-09-24 16:43 ` Liviu Dudau
2014-09-24 17:31 ` Bjorn Helgaas
2014-09-24 17:53 ` Liviu Dudau
2014-09-24 18:01 ` Will Deacon
2014-09-25 8:54 ` Liviu Dudau
2014-09-25 9:04 ` Will Deacon
2014-09-23 19:01 ` [PATCH v12 10/12] PCI: Assign unassigned bus resources in pci_scan_root_bus() Liviu Dudau
2014-09-24 1:18 ` Liviu Dudau
2014-09-24 1:41 ` Bjorn Helgaas
2014-09-24 1:48 ` Liviu Dudau
2014-09-28 21:16 ` Suravee Suthikulpanit
2014-09-29 18:18 ` Arnd Bergmann
2014-09-23 19:01 ` [PATCH v12 11/12] PCI: Introduce pci_remap_iospace() for remapping PCI I/O bus resources into CPU space Liviu Dudau
2014-09-23 19:01 ` [PATCH v12 12/12] arm64: Add architectural support for PCIe Liviu Dudau
2014-09-23 21:54 ` [PATCH v12 00/12] Support for creating generic PCI host bridges from DT Bjorn Helgaas
2014-09-23 22:48 ` Liviu Dudau
2014-09-23 23:00 ` Bjorn Helgaas
2014-09-24 13:30 ` Rob Herring
2014-09-24 14:23 ` Liviu Dudau
2014-09-24 15:38 ` Bjorn Helgaas
2014-09-23 22:49 ` Liviu Dudau
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