linux.git/arch/powerpc/kernel/pci-hotplug.c, branch v4.19

powerpc/pci: Unroll two pass loop when scanning bridges

2017-12-19T05:05:52+00:00

The current scanning code is really hard to understand because it calls the
same function in a loop where pass value is changed without any comments
explaining it:

  for (pass = 0; pass < 2; pass++)
    for_each_pci_bridge(dev, bus)
      max = pci_scan_bridge(bus, dev, max, pass);

Unfamiliar reader cannot tell easily what is the purpose of this loop
without looking at internals of pci_scan_bridge().

In order to make this bit easier to understand, open-code the loop in
pci_scan_child_bus() and pci_hp_add_bridge() with added comments.

No functional changes intended.

Signed-off-by: Andy Shevchenko 
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Mika Westerberg

powerpc/pci: Use for_each_pci_bridge() helper

2017-12-19T05:05:52+00:00

Use for_each_pci_bridge() helper to make the code slightly cleaner.  No
functional change intended.

Requires: 24a0c654d7d6 ("PCI: Add for_each_pci_bridge() helper")
Signed-off-by: Andy Shevchenko 
Signed-off-by: Bjorn Helgaas 
Acked-by: Michael Ellerman

powerpc/pci: Don't scan empty slot

2016-05-11T11:54:26+00:00

In hotplug case, function pci_add_pci_devices() is called to rescan
the specified PCI bus, which might not have any child devices. Access
to the PCI bus's child device node will cause kernel crash without
exception.

This adds one more check to skip scanning PCI bus that doesn't have
any subordinate devices from device-tree, in order to avoid kernel
crash.

Signed-off-by: Gavin Shan 
Reviewed-by: Alexey Kardashevskiy 
Signed-off-by: Michael Ellerman

powerpc/pci: Move pci_find_bus_by_node() around

2016-05-11T11:54:24+00:00

This moves pci_find_bus_by_node() from arch/powerpc/platforms/
pseries/pci_dlpar.c to arch/powerpc/kernel/pci-hotplug.c so that
the function can be used by pSeries and PowerNV platform at the
same time. Also, below cleanup applied. No functional changes
introduced.

   * Remove variable "busdn" in find_bus_among_children()
   * Use PCI_DN() to convert device node to pci_dn

Signed-off-by: Gavin Shan 
Acked-by: Benjamin Herrenschmidt 
Reviewed-by: Andrew Donnellan 
Reviewed-by: Alexey Kardashevskiy 
Signed-off-by: Michael Ellerman

powerpc/pci: Rename pcibios_{add, remove}_pci_devices()

2016-05-11T11:54:23+00:00

This renames pcibios_{add,remove}_pci_devices() to avoid conflicts
with names of the weak functions in PCI subsystem, which have the
prefix "pcibios". No logical changes introduced.

Signed-off-by: Gavin Shan 
Reviewed-By: Alistair Popple 
Reviewed-by: Andrew Donnellan 
Reviewed-by: Alexey Kardashevskiy 
Signed-off-by: Michael Ellerman

powerpc/pci: Remove VFs prior to PF

2016-03-08T22:58:15+00:00

As commit ac205b7bb72f ("PCI: make sriov work with hotplug remove")
indicates, VFs which is on the same PCI bus as their PF, should be
removed before the PF. Otherwise, we might run into kernel crash
at PCI unplugging time.

This applies the above pattern to powerpc PCI hotplug path.

Signed-off-by: Wei Yang 
Acked-by: Gavin Shan 
Signed-off-by: Michael Ellerman

powerpc/pci: Add release_device() hook to phb ops

2015-06-03T03:27:15+00:00

Add release_device() hook to phb ops so we can clean up for specific phbs.

Signed-off-by: Michael Neuling 
Signed-off-by: Michael Ellerman

powerpc: Remove shims for pci_controller_ops operations

2015-04-11T10:49:18+00:00

Remove shims, patch callsites to use pci_controller_ops
versions instead.

Also move back the probe mode defines, as explained in the patch
for pci_probe_mode.

Signed-off-by: Daniel Axtens 
Signed-off-by: Michael Ellerman

powerpc: Create pci_controller_ops.probe_mode and shim

2015-04-11T10:49:12+00:00

Add pci_controller_ops.probe_mode, shadowing ppc_md.pci_probe_mode.
Add a shim, and changes the callsites to use the shim.

We also need to move the probe mode defines to pci-bridge.h from pci.h.
They are required by the shim in order to return a sensible default.
Previously, the were defined in pci.h, but pci.h includes pci-bridge.h
before the relevant #defines. This means the definitions are absent
if pci.h is included before pci-bridge.h. This occurs in some drivers.
So, move the definitons now, and move them back when we remove the shim.

Anything that wants the defines would have had to include pci.h, and
since pci.h includes pci-bridge.h, nothing will lose access to the
defines.

Signed-off-by: Daniel Axtens 
Signed-off-by: Michael Ellerman

powerpc/eeh: Do probe on pci_dn

2015-03-24T02:15:52+00:00

Originally, EEH core probes on device_node or pci_dev to populate
EEH devices and PEs, which conflicts with the fact: SRIOV VFs are
usually enabled and created by PF's driver and they don't have the
corresponding device_nodes. Instead, SRIOV VFs have dynamically
created pci_dn, which can be used for EEH probe.

The patch reworks EEH probe for PowerNV and pSeries platforms to
do probing based on pci_dn, instead of pci_dev or device_node any
more.

Signed-off-by: Gavin Shan 
Signed-off-by: Benjamin Herrenschmidt