From: arnd@arndb•de (Arnd Bergmann)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v8 4/9] pci: OF: Fix the conversion of IO ranges into IO resources.
Date: Mon, 7 Jul 2014 23:22:00 +0200 [thread overview]
Message-ID: <201407072322.00990.arnd@arndb.de> (raw)
In-Reply-To: <20140707111133.GP6501@e106497-lin.cambridge.arm.com>
On Monday 07 July 2014, Liviu Dudau wrote:
> On Sat, Jul 05, 2014 at 09:46:09PM +0100, Arnd Bergmann wrote:
> > On Saturday 05 July 2014 14:25:52 Rob Herring wrote:
> > > On Tue, Jul 1, 2014 at 1:43 PM, Liviu Dudau <Liviu.Dudau@arm•com> wrote:
> > > > The ranges property for a host bridge controller in DT describes
> > > > the mapping between the PCI bus address and the CPU physical address.
> > > > The resources framework however expects that the IO resources start
> > > > at a pseudo "port" address 0 (zero) and have a maximum size of IO_SPACE_LIMIT.
> > > > The conversion from pci ranges to resources failed to take that into account.
> > >
> > > I don't think this change is right. There are 2 resources: the PCI bus
> > > addresses and cpu addresses. This function deals with the cpu
> > > addresses. Returning pci addresses for i/o and cpu addresses for
> > > memory is going to be error prone. We probably need both cpu and pci
> > > resources exposed to host controllers.
> > >
> > > Making the new function only deal with i/o bus resources and naming it
> > > of_pci_range_to_io_resource would be better.
> >
> > I think you are correct that this change by itself is will break existing
> > drivers that rely on the current behavior of of_pci_range_to_resource,
> > but there is also something wrong with the existing implementation:
>
> Either I'm very confused or I've managed to confuse everyone else. The I/O
> resources described using CPU addresses *are* using "pseudo" port based
> addresses (or at least that is my understanding and my reading of the code).
> Can you point me to a function that is expecting the IO resource to have
> the start address at the physical address of the mapped space?
pci_v3_preinit() in arch/arm/mach-integrator/pci_v3.c for instance takes
the resource returned by of_pci_range_to_resource and programs the
start and size into hardware registers that expect a physical address
as far as I can tell.
> I was trying to fix exactly this issue, that you cannot use the resource
> structure returned by this function in any call that is expecting an IO
> resource.
I looked at the other drivers briefly, and I think you indeed fix the Tegra
driver with this but break the integrator driver as mentioned above.
The other callers of of_pci_range_to_resource() are apparently not
impacted as they recalculate the values they get.
Arnd
next prev parent reply other threads:[~2014-07-07 21:22 UTC|newest]
Thread overview: 92+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-01 18:43 [PATCH v8 0/9] Support for creating generic PCI host bridges from DT Liviu Dudau
2014-07-01 18:43 ` [PATCH v8 1/9] Fix ioport_map() for !CONFIG_GENERIC_IOMAP cases Liviu Dudau
2014-07-01 18:43 ` [PATCH v8 2/9] pci: Export find_pci_host_bridge() function Liviu Dudau
2014-07-02 18:06 ` Tanmay Inamdar
2014-07-02 19:12 ` Arnd Bergmann
2014-07-02 20:43 ` Tanmay Inamdar
2014-07-03 9:53 ` Liviu Dudau
2014-07-03 10:26 ` Arnd Bergmann
2014-07-07 23:27 ` Bjorn Helgaas
2014-07-08 10:42 ` Liviu Dudau
2014-07-01 18:43 ` [PATCH v8 3/9] pci: Introduce pci_register_io_range() helper function Liviu Dudau
2014-07-01 19:36 ` Arnd Bergmann
2014-07-01 20:45 ` Liviu Dudau
2014-07-02 12:30 ` Arnd Bergmann
2014-07-02 14:23 ` Liviu Dudau
2014-07-02 14:58 ` Arnd Bergmann
2014-07-02 11:22 ` Will Deacon
2014-07-02 16:00 ` Liviu Dudau
2014-07-02 12:38 ` Arnd Bergmann
2014-07-02 13:20 ` Liviu Dudau
2014-07-08 0:14 ` Bjorn Helgaas
2014-07-08 7:00 ` Arnd Bergmann
2014-07-08 21:29 ` Bjorn Helgaas
2014-07-08 22:45 ` Liviu Dudau
2014-07-09 6:32 ` Arnd Bergmann
2014-07-09 9:13 ` Liviu Dudau
2014-07-09 6:20 ` Arnd Bergmann
2014-07-09 9:14 ` Liviu Dudau
2014-07-09 15:21 ` Bjorn Helgaas
2014-07-08 10:40 ` Liviu Dudau
2014-07-08 14:14 ` Arnd Bergmann
2014-07-09 8:59 ` Liviu Dudau
2014-07-01 18:43 ` [PATCH v8 4/9] pci: OF: Fix the conversion of IO ranges into IO resources Liviu Dudau
2014-07-05 19:25 ` Rob Herring
2014-07-05 20:46 ` Arnd Bergmann
2014-07-07 11:11 ` Liviu Dudau
2014-07-07 21:22 ` Arnd Bergmann [this message]
2014-07-08 10:03 ` Liviu Dudau
2014-07-09 8:31 ` Arnd Bergmann
2014-07-09 9:27 ` Liviu Dudau
2014-07-16 14:35 ` Rob Herring
2014-07-16 14:47 ` Liviu Dudau
2014-07-16 14:47 ` Arnd Bergmann
2014-07-01 18:43 ` [PATCH v8 5/9] pci: Create pci_host_bridge before its associated bus in pci_create_root_bus Liviu Dudau
2014-07-01 18:43 ` [PATCH v8 6/9] pci: Introduce a domain number for pci_host_bridge Liviu Dudau
2014-07-08 0:59 ` Bjorn Helgaas
2014-07-08 10:46 ` Liviu Dudau
2014-07-08 18:41 ` Bjorn Helgaas
2014-07-08 22:48 ` Liviu Dudau
2014-07-09 15:10 ` Bjorn Helgaas
2014-07-10 9:47 ` Liviu Dudau
2014-07-10 22:36 ` Bjorn Helgaas
2014-07-11 9:30 ` Liviu Dudau
2014-07-11 14:11 ` Catalin Marinas
2014-07-11 15:08 ` Liviu Dudau
2014-07-11 16:09 ` Catalin Marinas
2014-07-11 17:02 ` Bjorn Helgaas
2014-07-11 18:02 ` Catalin Marinas
2014-07-14 16:39 ` Catalin Marinas
2014-07-22 3:15 ` Bjorn Helgaas
2014-07-25 15:42 ` Catalin Marinas
2014-07-01 18:43 ` [PATCH v8 7/9] pci: of: Parse and map the IRQ when adding the PCI device Liviu Dudau
2014-07-02 11:17 ` Will Deacon
2014-07-05 19:04 ` Rob Herring
2014-07-01 18:43 ` [PATCH v8 8/9] pci: Add support for creating a generic host_bridge from device tree Liviu Dudau
2014-07-01 20:50 ` [RESEND] " Liviu Dudau
2014-07-01 21:04 ` Liviu Dudau
2014-07-02 11:22 ` Will Deacon
2014-07-02 17:23 ` Liviu Dudau
2014-07-02 17:31 ` Will Deacon
2014-07-02 19:09 ` Arnd Bergmann
2014-07-08 1:01 ` Bjorn Helgaas
2014-07-08 10:29 ` Liviu Dudau
2014-07-08 21:33 ` Bjorn Helgaas
2014-07-08 22:27 ` Liviu Dudau
2014-07-08 22:37 ` Bjorn Helgaas
2014-07-08 22:57 ` Liviu Dudau
2014-07-09 6:47 ` Arnd Bergmann
2014-07-11 7:43 ` Jingoo Han
2014-07-11 9:08 ` Liviu Dudau
2014-07-01 18:43 ` [PATCH v8 9/9] pci: Remap I/O bus resources into CPU space with pci_remap_iospace() Liviu Dudau
2014-07-14 16:54 ` Catalin Marinas
2014-07-14 16:56 ` Liviu Dudau
2014-07-14 18:15 ` Arnd Bergmann
2014-07-15 0:14 ` Liviu Dudau
2014-07-15 9:09 ` Catalin Marinas
2014-07-06 15:23 ` [PATCH v8 0/9] Support for creating generic PCI host bridges from DT Rob Herring
2014-07-07 11:12 ` Liviu Dudau
2014-07-08 17:18 ` Liviu Dudau
2014-07-11 0:44 ` Tanmay Inamdar
2014-07-11 7:33 ` Jingoo Han
2014-07-11 9:11 ` Liviu Dudau
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