Re: [PATCH V6 05/13] acpi, pci: Support IO resources when parsing PCI host bridge resources.

From	Bjorn Helgaas <helgaas@kernel.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH V6 05/13] acpi, pci: Support IO resources when parsing PCI host bridge resources.
Date	2016-04-28 17:50 +0200
Message-ID	<rsWmv-5UH-29@gated-at.bofh.it> (permalink)
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On Wed, Apr 27, 2016 at 03:26:59PM +0100, Lorenzo Pieralisi wrote:
> On Tue, Apr 26, 2016 at 09:39:16PM -0500, Bjorn Helgaas wrote:
> > On Fri, Apr 15, 2016 at 07:06:40PM +0200, Tomasz Nowicki wrote:
> > > Platforms that have memory mapped IO port (such as ARM64) need special
> > > handling for PCI I/O resources. For host bridge's resource probing case
> > > these resources need to be fixed up with pci_register_io_range/pci_remap_iospace etc.
> > 
> > ia64 also has memory-mapped I/O port space.  It would be ideal to find
> > some way to handle ia64 and ARM64 similarly.  At the very least, we
> > have to make sure that this doesn't break ia64.  The ia64 dense/sparse
> > I/O spaces complicate things; I don't know if ARM64 has something
> > similar or not.
> 
> No it does not, and that's exactly the same problem we faced with
> the DT generic version of of_pci_range_to_resource() which basically
> relies on PCI_IOBASE to be defined to add code that creates IO port
> resources out of the MMIO resource describing how IO port space is
> mapped to MMIO (physical) address space.

Mapping IO port space into MMIO space is pretty common since most
arches don't have inb/outb instructions like x86 does.  Several arches
(at least ia64 and parisc) have some sort of sparse mapping, but my
point is that the "dense" mapping (one byte MMIO space per IO port) is
pretty similar across arches.

There are differences in how we compute the MMIO address from the IO
port number, of course, e.g., on arm64 the CPU virtual MMIO address is
a simple offset from the IO port number, i.e., "vaddr = PCI_IOBASE +
res->start" in pci_remap_iospace(), while on ia64, that CPU address is
less constrained, i.e., "vaddr = space->mmio_base | port" in
__ia64_mk_io_addr().

> IIRC everything hinges on PCI_IOBASE definition to make sure that
> of_pci_range_to_resource() *works*, which means that if PCI_IOBASE is
> not defined (ie IA64) that code - acpi_pci_root_remap_iospace() in this
> case - does nothing.

OK.  That's confusing to read, but I see that it probably works.

> So acpi_pci_root_remap_iospace() is of_pci_range_to_resource() ACPI
> equivalent + the pci_remap_iospace() call (I have to dig into the
> logs to check why Liviu did not add a call to pci_remap_iospace()
> in of_pci_get_host_bridge_resources() - I want to do that actually).
> 
> The point here is: IO space (in DT and ACPI) handling is arch specific.
> 
> For DT, by relying on PCI_IOBASE, we left that code in drivers/of and
> it works (well, with some niggles - see the thread with Murali on IO
> space on TI keystone) for ARM/ARM64.
> 
> http://www.spinics.net/lists/linux-pci/msg49725.html
> 
> What are we going to do with the ACPI version ?
> 
> Do we want to add an arch specific call that takes the raw resource
> describing IO space and creates an IO port resource (and the MMIO
> equivalent - that's what add_io_space() does in IA64) and use that
> in generic ACPI parsing code ?

There's a lot of non-arch-specific stuff here, which is what's
bothering me.  The arch-specific parts are:

  - discovering IO port region (bus address start and size)
  - discovering MMIO mapping address and size (CPU "mem" resource)
  - discovering or assigning IO port base (CPU "io" resource)
  - setting up whatever structures arch uses to implement inb()

Once you have the CPU "mem" and "io" resources, the code to insert
them into iomem_resource and ioport_resource and ioremap() the MMIO
space should be pretty generic.  Right now that code is scattered
through the arches and most of them don't do it correctly, e.g.,
typically they don't request the "mem" resource.

Thread

[PATCH V6 00/13] Support for generic ACPI based PCI host controller Tomasz Nowicki <tn@semihalf.com> - 2016-04-15 19:10 +0200
  [PATCH V6 11/13] pci, acpi: Match PCI config space accessors against platfrom specific quirks. Tomasz Nowicki <tn@semihalf.com> - 2016-04-15 19:10 +0200
    Re: [PATCH V6 11/13] pci, acpi: Match PCI config space accessors  against platfrom specific quirks. "liudongdong (C)" <liudongdong3@huawei.com> - 2016-04-18 14:00 +0200
      Re: [PATCH V6 11/13] pci, acpi: Match PCI config space accessors  against platfrom specific quirks. Tomasz Nowicki <tn@semihalf.com> - 2016-04-18 14:30 +0200
  [PATCH V6 13/13] pci, pci-thunder-pem: Add ACPI support for ThunderX PEM. Tomasz Nowicki <tn@semihalf.com> - 2016-04-15 19:10 +0200
  [PATCH V6 02/13] pci, acpi: Provide generic way to assign bus domain number. Tomasz Nowicki <tn@semihalf.com> - 2016-04-15 19:10 +0200
    Re: [PATCH V6 02/13] pci, acpi: Provide generic way to assign bus  domain number. Bjorn Helgaas <helgaas@kernel.org> - 2016-04-27 04:30 +0200
      Re: [PATCH V6 02/13] pci, acpi: Provide generic way to assign bus  domain number. Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> - 2016-04-27 13:20 +0200
        Re: [PATCH V6 02/13] pci, acpi: Provide generic way to assign bus  domain number. Bjorn Helgaas <helgaas@kernel.org> - 2016-04-27 18:50 +0200
          Re: [PATCH V6 02/13] pci, acpi: Provide generic way to assign bus  domain number. Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> - 2016-04-27 19:40 +0200
            Re: [PATCH V6 02/13] pci, acpi: Provide generic way to assign bus  domain number. Liviu.Dudau@arm.com - 2016-04-28 10:20 +0200
            Re: [PATCH V6 02/13] pci, acpi: Provide generic way to assign bus  domain number. Bjorn Helgaas <helgaas@kernel.org> - 2016-04-28 17:20 +0200
              Re: [PATCH V6 02/13] pci, acpi: Provide generic way to assign bus domain number. Arnd Bergmann <arnd@arndb.de> - 2016-04-28 17:40 +0200
                Re: [PATCH V6 02/13] pci, acpi: Provide generic way to assign bus domain number. Arnd Bergmann <arnd@arndb.de> - 2016-04-30 01:00 +0200
        Re: [PATCH V6 02/13] pci, acpi: Provide generic way to assign bus  domain number. Tomasz Nowicki <tn@semihalf.com> - 2016-05-02 14:50 +0200
          Re: [PATCH V6 02/13] pci, acpi: Provide generic way to assign bus  domain number. Jayachandran C <jchandra@broadcom.com> - 2016-05-02 15:30 +0200
            Re: [PATCH V6 02/13] pci, acpi: Provide generic way to assign bus  domain number. Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> - 2016-05-03 13:10 +0200
              Re: [PATCH V6 02/13] pci, acpi: Provide generic way to assign bus  domain number. Jayachandran C <jchandra@broadcom.com> - 2016-05-03 16:30 +0200
                Re: [PATCH V6 02/13] pci, acpi: Provide generic way to assign bus  domain number. Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> - 2016-05-03 17:00 +0200
      Re: [PATCH V6 02/13] pci, acpi: Provide generic way to assign bus  domain number. Tomasz Nowicki <tn@semihalf.com> - 2016-04-27 14:10 +0200
  [PATCH V6 12/13] pci, pci-thunder-ecam: Add ACPI support for ThunderX ECAM. Tomasz Nowicki <tn@semihalf.com> - 2016-04-15 19:10 +0200
    Re: [PATCH V6 12/13] pci, pci-thunder-ecam: Add ACPI support for  ThunderX ECAM. Tomasz Nowicki <tn@semihalf.com> - 2016-04-19 12:30 +0200
      Re: [Linaro-acpi] [PATCH V6 12/13] pci, pci-thunder-ecam: Add ACPI  support for ThunderX ECAM. G Gregory <graeme.gregory@linaro.org> - 2016-04-19 12:50 +0200
        Re: [Linaro-acpi] [PATCH V6 12/13] pci, pci-thunder-ecam: Add ACPI  support for ThunderX ECAM. Graeme Gregory <gg@slimlogic.co.uk> - 2016-04-19 13:20 +0200
          Re: [Linaro-acpi] [PATCH V6 12/13] pci, pci-thunder-ecam: Add ACPI  support for ThunderX ECAM. Tomasz Nowicki <tn@semihalf.com> - 2016-04-19 13:30 +0200
            Re: [Linaro-acpi] [PATCH V6 12/13] pci, pci-thunder-ecam: Add ACPI  support for ThunderX ECAM. G Gregory <graeme.gregory@linaro.org> - 2016-04-19 14:30 +0200
  [PATCH V6 08/13] PCI: generic, thunder: update to use generic ECAM API Tomasz Nowicki <tn@semihalf.com> - 2016-04-15 19:10 +0200
    Re: [PATCH V6 08/13] PCI: generic, thunder: update to use generic ECAM API Arnd Bergmann <arnd@arndb.de> - 2016-04-15 20:50 +0200
      Re: [PATCH V6 08/13] PCI: generic, thunder: update to use generic  ECAM API Jayachandran C <jchandra@broadcom.com> - 2016-04-16 09:30 +0200
        Re: [PATCH V6 08/13] PCI: generic, thunder: update to use generic ECAM API Arnd Bergmann <arnd@arndb.de> - 2016-04-16 09:40 +0200
          Re: [PATCH V6 08/13] PCI: generic, thunder: update to use generic  ECAM API Jayachandran C <jchandra@broadcom.com> - 2016-04-16 16:40 +0200
            Re: [PATCH V6 08/13] PCI: generic, thunder: update to use generic  ECAM API Tomasz Nowicki <tn@semihalf.com> - 2016-04-18 15:10 +0200
              Re: [PATCH V6 08/13] PCI: generic, thunder: update to use generic ECAM API Arnd Bergmann <arnd@arndb.de> - 2016-04-18 16:50 +0200
                Re: [PATCH V6 08/13] PCI: generic, thunder: update to use generic  ECAM API Tomasz Nowicki <tn@semihalf.com> - 2016-04-18 21:40 +0200
                Re: [PATCH V6 08/13] PCI: generic, thunder: update to use generic ECAM API Arnd Bergmann <arnd@arndb.de> - 2016-04-19 15:10 +0200
                Re: [PATCH V6 08/13] PCI: generic, thunder: update to use generic  ECAM API Tomasz Nowicki <tn@semihalf.com> - 2016-04-21 11:30 +0200
                Re: [PATCH V6 08/13] PCI: generic, thunder: update to use generic ECAM API Arnd Bergmann <arnd@arndb.de> - 2016-04-21 11:40 +0200
                Re: [PATCH V6 08/13] PCI: generic, thunder: update to use generic  ECAM API Tomasz Nowicki <tn@semihalf.com> - 2016-04-21 12:10 +0200
                Re: [PATCH V6 08/13] PCI: generic, thunder: update to use generic  ECAM API Jon Masters <jcm@redhat.com> - 2016-04-22 16:40 +0200
                Re: [PATCH V6 08/13] PCI: generic, thunder: update to use generic  ECAM API David Daney <ddaney.cavm@gmail.com> - 2016-04-22 18:10 +0200
                Re: [PATCH V6 08/13] PCI: generic, thunder: update to use generic  ECAM API Bjorn Helgaas <helgaas@kernel.org> - 2016-04-28 22:20 +0200
                Re: [PATCH V6 08/13] PCI: generic, thunder: update to use generic ECAM API Arnd Bergmann <arnd@arndb.de> - 2016-04-28 22:50 +0200
                Re: [PATCH V6 08/13] PCI: generic, thunder: update to use generic  ECAM API Bjorn Helgaas <helgaas@kernel.org> - 2016-04-28 23:20 +0200
                Re: [PATCH V6 08/13] PCI: generic, thunder: update to use generic  ECAM API Jon Masters <jcm@redhat.com> - 2016-04-28 23:50 +0200
                Re: [PATCH V6 08/13] PCI: generic, thunder: update to use generic  ECAM API Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> - 2016-04-29 11:50 +0200
    Re: [PATCH V6 08/13] PCI: generic, thunder: update to use generic ECAM API Arnd Bergmann <arnd@arndb.de> - 2016-04-19 23:50 +0200
      Re: [PATCH V6 08/13] PCI: generic, thunder: update to use generic  ECAM API Jayachandran C <jchandra@broadcom.com> - 2016-04-20 02:30 +0200
  [PATCH V6 04/13] pci, of: Move the PCI I/O space management to PCI core code. Tomasz Nowicki <tn@semihalf.com> - 2016-04-15 19:10 +0200
  [PATCH V6 09/13] pci, acpi: Support for ACPI based generic PCI host controller Tomasz Nowicki <tn@semihalf.com> - 2016-04-15 19:10 +0200
    Re: [PATCH V6 09/13] pci, acpi: Support for ACPI based generic PCI  host controller Jayachandran C <jchandra@broadcom.com> - 2016-04-20 21:20 +0200
      Re: [PATCH V6 09/13] pci, acpi: Support for ACPI based generic PCI  host controller Tomasz Nowicki <tn@semihalf.com> - 2016-04-21 11:10 +0200
        Re: [PATCH V6 09/13] pci, acpi: Support for ACPI based generic PCI  host controller Jayachandran C <jchandra@broadcom.com> - 2016-04-22 15:00 +0200
        Re: [PATCH V6 09/13] pci, acpi: Support for ACPI based generic PCI  host controller Jon Masters <jcm@redhat.com> - 2016-04-22 16:50 +0200
          Re: [PATCH V6 09/13] pci, acpi: Support for ACPI based generic PCI  host controller Jon Masters <jcm@redhat.com> - 2016-04-23 17:30 +0200
    Re: [PATCH V6 09/13] pci, acpi: Support for ACPI based generic PCI  host controller Bjorn Helgaas <helgaas@kernel.org> - 2016-04-28 23:50 +0200
      Re: [PATCH V6 09/13] pci, acpi: Support for ACPI based generic PCI  host controller Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> - 2016-04-29 10:40 +0200
        Re: [PATCH V6 09/13] pci, acpi: Support for ACPI based generic PCI  host controller Jayachandran C <jchandra@broadcom.com> - 2016-04-29 19:40 +0200
          Re: [PATCH V6 09/13] pci, acpi: Support for ACPI based generic PCI  host controller Tomasz Nowicki <tn@semihalf.com> - 2016-05-02 13:40 +0200
          Re: [PATCH V6 09/13] pci, acpi: Support for ACPI based generic PCI  host controller Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> - 2016-05-03 10:50 +0200
      Re: [PATCH V6 09/13] pci, acpi: Support for ACPI based generic PCI  host controller Tomasz Nowicki <tn@semihalf.com> - 2016-05-02 13:10 +0200
  [PATCH V6 10/13] arm64, pci, acpi: Start using ACPI based PCI host controller driver for ARM64. Tomasz Nowicki <tn@semihalf.com> - 2016-04-15 19:10 +0200
  [PATCH V6 06/13] arm64, pci, acpi: ACPI support for legacy IRQs parsing and consolidation with DT code. Tomasz Nowicki <tn@semihalf.com> - 2016-04-15 19:20 +0200
    Re: [PATCH V6 06/13] arm64, pci, acpi: ACPI support for legacy IRQs  parsing and consolidation with DT code. Bjorn Helgaas <helgaas@kernel.org> - 2016-04-27 04:50 +0200
      Re: [PATCH V6 06/13] arm64, pci, acpi: ACPI support for legacy IRQs  parsing and consolidation with DT code. Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> - 2016-04-27 13:50 +0200
  [PATCH V6 07/13] PCI: Provide common functions for ECAM mapping Tomasz Nowicki <tn@semihalf.com> - 2016-04-15 19:20 +0200
    Re: [PATCH V6 07/13] PCI: Provide common functions for ECAM mapping Arnd Bergmann <arnd@arndb.de> - 2016-04-15 20:50 +0200
    Re: [PATCH V6 07/13] PCI: Provide common functions for ECAM mapping Bjorn Helgaas <helgaas@kernel.org> - 2016-04-28 23:50 +0200
      Re: [PATCH V6 07/13] PCI: Provide common functions for ECAM mapping Jayachandran C <jchandra@broadcom.com> - 2016-04-29 10:10 +0200
        Re: [PATCH V6 07/13] PCI: Provide common functions for ECAM mapping Jayachandran C <jchandra@broadcom.com> - 2016-05-05 11:30 +0200
          Re: [PATCH V6 07/13] PCI: Provide common functions for ECAM mapping Tomasz Nowicki <tn@semihalf.com> - 2016-05-05 12:40 +0200
  [PATCH V6 01/13] pci, acpi, x86, ia64: Move ACPI host bridge device companion assignment to core code. Tomasz Nowicki <tn@semihalf.com> - 2016-04-15 19:20 +0200
    Re: [PATCH V6 01/13] pci, acpi, x86, ia64: Move ACPI host bridge  device companion assignment to core code. Bjorn Helgaas <helgaas@kernel.org> - 2016-04-27 00:40 +0200
      Re: [PATCH V6 01/13] pci, acpi, x86, ia64: Move ACPI host bridge  device companion assignment to core code. Tomasz Nowicki <tn@semihalf.com> - 2016-04-27 12:20 +0200
    Re: [PATCH V6 01/13] pci, acpi, x86, ia64: Move ACPI host bridge  device companion assignment to core code. Bjorn Helgaas <helgaas@kernel.org> - 2016-04-27 04:50 +0200
      Re: [PATCH V6 01/13] pci, acpi, x86, ia64: Move ACPI host bridge  device companion assignment to core code. Tomasz Nowicki <tn@semihalf.com> - 2016-05-04 10:20 +0200
        Re: [PATCH V6 01/13] pci, acpi, x86, ia64: Move ACPI host bridge device companion assignment to core code. "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-05-10 00:20 +0200
          Re: [PATCH V6 01/13] pci, acpi, x86, ia64: Move ACPI host bridge  device companion assignment to core code. Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> - 2016-05-10 12:30 +0200
    Re: [PATCH V6 01/13] pci, acpi, x86, ia64: Move ACPI host bridge device companion assignment to core code. "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-05-10 01:00 +0200
      Re: [PATCH V6 01/13] pci, acpi, x86, ia64: Move ACPI host bridge  device companion assignment to core code. Bjorn Helgaas <helgaas@kernel.org> - 2016-05-10 04:00 +0200
        Re: [PATCH V6 01/13] pci, acpi, x86, ia64: Move ACPI host bridge  device companion assignment to core code. Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> - 2016-05-10 12:10 +0200
  [PATCH V6 03/13] x86, ia64: Include acpi_pci_{add|remove}_bus to the default pcibios_{add|remove}_bus implementation. Tomasz Nowicki <tn@semihalf.com> - 2016-04-15 19:20 +0200
    Re: [PATCH V6 03/13] x86, ia64: Include acpi_pci_{add|remove}_bus to  the default pcibios_{add|remove}_bus implementation. Bjorn Helgaas <helgaas@kernel.org> - 2016-04-27 04:40 +0200
      Re: [PATCH V6 03/13] x86, ia64: Include acpi_pci_{add|remove}_bus to  the default pcibios_{add|remove}_bus implementation. Tomasz Nowicki <tn@semihalf.com> - 2016-04-27 15:30 +0200
  [PATCH V6 05/13] acpi, pci: Support IO resources when parsing PCI host bridge resources. Tomasz Nowicki <tn@semihalf.com> - 2016-04-15 19:20 +0200
    Re: [PATCH V6 05/13] acpi, pci: Support IO resources when parsing  PCI host bridge resources. Bjorn Helgaas <helgaas@kernel.org> - 2016-04-27 04:40 +0200
      Re: [PATCH V6 05/13] acpi, pci: Support IO resources when parsing PCI  host bridge resources. Jon Masters <jcm@redhat.com> - 2016-04-27 07:40 +0200
        Re: [PATCH V6 05/13] acpi, pci: Support IO resources when parsing PCI  host bridge resources. Jon Masters <jcm@redhat.com> - 2016-04-29 00:00 +0200
      Re: [PATCH V6 05/13] acpi, pci: Support IO resources when parsing  PCI host bridge resources. Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> - 2016-04-27 16:30 +0200
        Re: [PATCH V6 05/13] acpi, pci: Support IO resources when parsing  PCI host bridge resources. Liviu.Dudau@arm.com - 2016-04-27 17:20 +0200
          Re: [PATCH V6 05/13] acpi, pci: Support IO resources when parsing  PCI host bridge resources. Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> - 2016-04-27 18:10 +0200
        Re: [PATCH V6 05/13] acpi, pci: Support IO resources when parsing  PCI host bridge resources. Bjorn Helgaas <helgaas@kernel.org> - 2016-04-28 17:50 +0200
  Re: [PATCH V6 00/13] Support for generic ACPI based PCI host  controller Jon Masters <jcm@redhat.com> - 2016-04-15 20:20 +0200
    Re: [PATCH V6 00/13] Support for generic ACPI based PCI host controller Jayachandran C <jchandra@broadcom.com> - 2016-04-16 17:40 +0200
      Re: [PATCH V6 00/13] Support for generic ACPI based PCI host  controller Tomasz Nowicki <tn@semihalf.com> - 2016-04-18 15:40 +0200
        Re: [PATCH V6 00/13] Support for generic ACPI based PCI host controller Arnd Bergmann <arnd@arndb.de> - 2016-04-18 16:40 +0200
          Re: [PATCH V6 00/13] Support for generic ACPI based PCI host  controller Tomasz Nowicki <tn@semihalf.com> - 2016-04-18 17:30 +0200
    Re: [PATCH V6 00/13] Support for generic ACPI based PCI host controller Martinez Kristofer <kristofer.s.martinez@gmail.com> - 2016-04-17 11:30 +0200
  Re: [PATCH V6 00/13] Support for generic ACPI based PCI host controller Duc Dang <dhdang@apm.com> - 2016-04-16 20:40 +0200
  Re: [PATCH V6 00/13] Support for generic ACPI based PCI host  controller Sinan Kaya <okaya@codeaurora.org> - 2016-04-17 06:20 +0200
  Re: [PATCH V6 00/13] Support for generic ACPI based PCI host  controller Jeremy Linton <jeremy.linton@arm.com> - 2016-04-25 19:30 +0200
  [PATCH] acpi: pci: QDF2432 32 bit config space accessors Christopher Covington <cov@codeaurora.org> - 2016-04-28 23:30 +0200
    Re: [PATCH] acpi: pci: QDF2432 32 bit config space accessors "Rafael J. Wysocki" <rafael@kernel.org> - 2016-04-28 23:40 +0200

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