linux.git/arch/xtensa/kernel/pci.c, branch v4.4.288

PCI: Revert "PCI: Call pci_read_bridge_bases() from core instead of arch code"

2015-09-15T18:18:04+00:00

Revert dff22d2054b5 ("PCI: Call pci_read_bridge_bases() from core instead
of arch code").

Reading PCI bridge windows is not arch-specific in itself, but there is PCI
core code that doesn't work correctly if we read them too early. For
example, Hannes found this case on an ARM Freescale i.mx6 board:

pci_bus 0000:00: root bus resource [mem 0x01000000-0x01efffff]
pci 0000:00:00.0: PCI bridge to [bus 01-ff]
pci 0000:00:00.0: BAR 8: no space for [mem size 0x01000000] (mem window)
pci 0000:01:00.0: BAR 2: failed to assign [mem size 0x00200000]
pci 0000:01:00.0: BAR 1: failed to assign [mem size 0x00004000]
pci 0000:01:00.0: BAR 0: failed to assign [mem size 0x00000100]

The 00:00.0 mem window needs to be at least 3MB: the 01:00.0 device needs
0x204100 of space, and mem windows are megabyte-aligned.

Bus sizing can increase a bridge window size, but never *decrease* it (see
d65245c3297a ("PCI: don't shrink bridge resources")). Prior to
dff22d2054b5, ARM didn't read bridge windows at all, so the "original size"
was zero, and we assigned a 3MB window.

After dff22d2054b5, we read the bridge windows before sizing the bus. The
firmware programmed a 16MB window (size 0x01000000) in 00:00.0, and since
we never decrease the size, we kept 16MB even though we only needed 3MB.
But 16MB doesn't fit in the host bridge aperture, so we failed to assign
space for the window and the downstream devices.

I think this is a defect in the PCI core: we shouldn't rely on the firmware
to assign sensible windows.

Ray reported a similar problem, also on ARM, with Broadcom iProc.

Issues like this are too hard to fix right now, so revert dff22d2054b5.

Reported-by: Hannes
Reported-by: Ray Jui
Link: http://lkml.kernel.org/r/CAAa04yFQEUJm7Jj1qMT57-LG7ZGtnhNDBe=PpSRa70Mj+XhW-A@mail.gmail.com
Link: http://lkml.kernel.org/r/55F75BB8.4070405@broadcom.com
Signed-off-by: Bjorn Helgaas
Acked-by: Yinghai Lu
Acked-by: Lorenzo Pieralisi

PCI: Call pci_read_bridge_bases() from core instead of arch code

2015-07-23T15:13:29+00:00

When we scan a PCI bus, we read PCI-PCI bridge window registers with
pci_read_bridge_bases() so we can validate the resource hierarchy.  Most
architectures call pci_read_bridge_bases() from pcibios_fixup_bus(), but
PCI-PCI bridges are not arch-specific, so this doesn't need to be in
arch-specific code.

Call pci_read_bridge_bases() directly from the PCI core instead of from
arch code.

For alpha and mips, we now call pci_read_bridge_bases() always; previously
we only called it if PCI_PROBE_ONLY was set.

[bhelgaas: changelog]
Signed-off-by: Lorenzo Pieralisi 
Signed-off-by: Bjorn Helgaas 
CC: Ralf Baechle 
CC: James E.J. Bottomley 
CC: Michael Ellerman 
CC: Bjorn Helgaas 
CC: Richard Henderson 
CC: Benjamin Herrenschmidt 
CC: David Howells 
CC: Russell King 
CC: Tony Luck 
CC: David S. Miller 
CC: Ingo Molnar 
CC: Guenter Roeck 
CC: Michal Simek 
CC: Chris Zankel

PCI: Assign resources before drivers claim devices (pci_scan_root_bus())

2015-03-19T15:17:13+00:00

Previously, pci_scan_root_bus() created a root PCI bus, enumerated the
devices on it, and called pci_bus_add_devices(), which made the devices
available for drivers to claim them.

Most callers assigned resources to devices after pci_scan_root_bus()
returns, which may be after drivers have claimed the devices.  This is
incorrect; the PCI core should not change device resources while a driver
is managing the device.

Remove pci_bus_add_devices() from pci_scan_root_bus() and do it after any
resource assignment in the callers.

Note that ARM's pci_common_init_dev() already called pci_bus_add_devices()
after pci_scan_root_bus(), so we only need to remove the first call:

  pci_common_init_dev
    pcibios_init_hw
      pci_scan_root_bus
        pci_bus_add_devices        # first call
    pci_bus_assign_resources
    pci_bus_add_devices            # second call

[bhelgaas: changelog, drop "root_bus" var in alpha common_init_pci(),
return failure earlier in mn10300, add "return" in x86 pcibios_scan_root(),
return early if xtensa platform_pcibios_fixup() fails]
Signed-off-by: Yijing Wang 
Signed-off-by: Bjorn Helgaas 
CC: Richard Henderson 
CC: Ivan Kokshaysky 
CC: Matt Turner 
CC: David Howells 
CC: Tony Luck 
CC: Michal Simek 
CC: Ralf Baechle 
CC: Koichi Yasutake 
CC: Sebastian Ott 
CC: "David S. Miller" 
CC: Chris Metcalf 
CC: Chris Zankel 
CC: Max Filippov 
CC: Thomas Gleixner

xtensa: fix section mismatch in pcibios_fixup_bus

2013-06-05T17:14:22+00:00

Remove __init annotation from pcibios_fixup_bus as is called from
pci_scan_child_bus which is not __init.

Also fix a couple of minor build warnings.

Signed-off-by: Max Filippov 
Signed-off-by: Chris Zankel

Merge tag 'xtensa-next-20121008' of git://github.com/czankel/xtensa-linux

2012-10-09T07:11:46+00:00

Pull Xtensa patchset from Chris Zankel:
 "The Xtensa tree has been broken for some time now, and this patchset
  brings it back to life.  It has been part of the linux-next tree for
  some time.

  Most changes are inside the xtensa subdirectory; the other changes
  mostly add another rule to already existing #ifdefs to exclude Xtensa,
  where required.  The only 'common' change is to add two more sections
  ('.xt.prop' and '.xt.lit') to the white list in modpost."

* tag 'xtensa-next-20121008' of git://github.com/czankel/xtensa-linux: (27 commits)
  xtensa: Setup CROSS_COMPILE at the top
  xtensa: drop CONFIG_EMBEDDED_RAMDISK
  xtensa: fix TIOCGSERIAL and TIOCSSERIAL definitions
  xtensa: provide dummy gcc intrinsics
  xtensa: add missing symbol exports
  parport: disable for xtensa arch
  xtensa: rename MISC SR definition to avoid name clashes
  hisax: disable build for big-endian xtensa
  xtensa: fix CODA build
  xtensa: fix parallel make
  xtensa: ISS: drop unused io.c
  xtensa: ISS: exit simulator in case of halt or poweroff
  xtensa: ISS: change keyboard polling rate
  xtensa: ISS: add platform_pcibios_init
  xtensa: ISS: add dummy serial.h for ISS platform
  xtensa: change default platform clock frequency to 10MHz
  xtensa: add ARCH_WANT_OPTIONAL_GPIOLIB to xtensa config
  xtensa: set NO_IOPORT to 'n' by default
  xtensa: adopt generic io routines
  xtensa: fix ioremap
  ...

xtensa/PCI: fix WT caching attribute

2012-10-03T22:11:13+00:00

Fix caching attributes setup providing correct _PAGE_CA_* names.

Signed-off-by: Max Filippov 
Signed-off-by: Chris Zankel

PCI: Provide a default pcibios_update_irq()

2012-09-18T23:28:21+00:00

Most architectures implement this in exactly the same way. Instead of
having each architecture duplicate this function, provide a single
implementation in the core and make it a weak symbol so that it can be
overridden on architectures where it is required.

Signed-off-by: Thierry Reding 
Signed-off-by: Bjorn Helgaas

PCI: Discard __init annotations for pci_fixup_irqs() and related functions

2012-09-18T23:22:25+00:00

Remove the __init annotations in order to keep pci_fixup_irqs() around
after init (e.g. for hotplug). This requires the same change for the
implementation of pcibios_update_irq() on all architectures. While at
it, all __devinit annotations are removed as well, since they will be
useless now that HOTPLUG is always on.

Signed-off-by: Thierry Reding 
Signed-off-by: Bjorn Helgaas 
Acked-by: Greg Kroah-Hartman

Merge branch 'pci/myron-pcibios_setup' into next

2012-07-05T21:31:05+00:00

* pci/myron-pcibios_setup:
  xtensa/PCI: factor out pcibios_setup()
  x86/PCI: adjust section annotations for pcibios_setup()
  unicore32/PCI: adjust section annotations for pcibios_setup()
  tile/PCI: factor out pcibios_setup()
  sparc/PCI: factor out pcibios_setup()
  sh/PCI: adjust section annotations for pcibios_setup()
  sh/PCI: factor out pcibios_setup()
  powerpc/PCI: factor out pcibios_setup()
  parisc/PCI: factor out pcibios_setup()
  MIPS/PCI: adjust section annotations for pcibios_setup()
  MIPS/PCI: factor out pcibios_setup()
  microblaze/PCI: factor out pcibios_setup()
  ia64/PCI: factor out pcibios_setup()
  cris/PCI: factor out pcibios_setup()
  alpha/PCI: factor out pcibios_setup()
  PCI: pull pcibios_setup() up into core

xtensa/PCI: factor out pcibios_setup()

2012-07-05T21:09:14+00:00

The PCI core provides a generic pcibios_setup() routine.  Drop this
architecture-specific version in favor of that.

Signed-off-by: Myron Stowe 
Signed-off-by: Bjorn Helgaas