linux-stable.git/arch/powerpc/kernel/eeh_driver.c, branch linux-4.5.y

powerpc/eeh: Restore initial state in eeh_pe_reset_and_recover()

2016-06-08T01:18:51+00:00

commit 5a0cdbfd17b90a89c64a71d8aec9773ecdb20d0d upstream.

The function eeh_pe_reset_and_recover() is used to recover EEH
error when the passthrou device are transferred to guest and
backwards. The content in the device's config space will be lost
on PE reset issued in the middle of the recovery. The function
saves/restores it before/after the reset. However, config access
to some adapters like Broadcom BCM5719 at this point will causes
fenced PHB. The config space is always blocked and we save 0xFF's
that are restored at late point. The memory BARs are totally
corrupted, causing another EEH error upon access to one of the
memory BARs.

This restores the config space on those adapters like BCM5719
from the content saved to the EEH device when it's populated,
to resolve above issue.

Fixes: 5cfb20b9 ("powerpc/eeh: Emulate EEH recovery for VFIO devices")
Signed-off-by: Gavin Shan 
Reviewed-by: Russell Currey 
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

powerpc/eeh: Don't report error in eeh_pe_reset_and_recover()

2016-06-08T01:18:51+00:00

commit affeb0f2d3a9af419ad7ef4ac782e1540b2f7b28 upstream.

The function eeh_pe_reset_and_recover() is used to recover EEH
error when the passthrough device are transferred to guest and
backwards, meaning the device's driver is vfio-pci or none.
When the driver is vfio-pci that provides error_detected() error
handler only, the handler simply stops the guest and it's not
expected behaviour. On the other hand, no error handlers will
be called if we don't have a bound driver.

This ignores the error handler in eeh_pe_reset_and_recover()
that reports the error to device driver to avoid the exceptional
behaviour.

Fixes: 5cfb20b9 ("powerpc/eeh: Emulate EEH recovery for VFIO devices")
Signed-off-by: Gavin Shan 
Reviewed-by: Russell Currey 
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

Merge tag 'powerpc-4.5-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2016-02-26T03:41:53+00:00

Pull powerpc fixes from Michael Ellerman:
 - eeh: Fix partial hotplug criterion from Gavin Shan
 - mm: Clear the invalid slot information correctly from Aneesh Kumar K.V

* tag 'powerpc-4.5-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/mm/hash: Clear the invalid slot information correctly
  powerpc/eeh: Fix partial hotplug criterion

powerpc/eeh: Fix partial hotplug criterion

2016-02-22T08:25:55+00:00

During error recovery, the device could be removed as part of the
partial hotplug. The criterion used to come with partial hotplug
is: if the device driver provides error_detected(), slot_reset()
and resume() callbacks, it's immune from hotplug. Otherwise,
it's going to experience partial hotplug during EEH recovery. But
the criterion isn't correct enough: mlx4_core driver for Mellanox
adapters provides error_detected(), slot_reset() callbacks, but
resume() isn't there. Those Mellanox adapters won't be to involved
in the partial hotplug.

This fixes the criterion to a practical one: adpater with driver
that provides error_detected(), slot_reset() will be immune from
partial hotplug. resume() isn't mandatory.

Fixes: f2da4ccf ("powerpc/eeh: More relaxed hotplug criterion")
Cc: stable@vger.kernel.org #v4.4+
Signed-off-by: Gavin Shan 
Signed-off-by: Michael Ellerman

Merge tag 'powerpc-4.5-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2016-02-20T17:22:11+00:00

Pull powerpc fixes from Michael Ellerman:
 - Fix build error on 32-bit with checkpoint restart from Aneesh Kumar
 - Fix dedotify for binutils >= 2.26 from Andreas Schwab
 - Don't trace hcalls on offline CPUs from Denis Kirjanov
 - eeh: Fix stale cached primary bus from Gavin Shan
 - eeh: Fix stale PE primary bus from Gavin Shan
 - mm: Fix Multi hit ERAT cause by recent THP update from Aneesh Kumar K.V
 - ioda: Set "read" permission when "write" is set from Alexey Kardashevskiy

* tag 'powerpc-4.5-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/ioda: Set "read" permission when "write" is set
  powerpc/mm: Fix Multi hit ERAT cause by recent THP update
  powerpc/powernv: Fix stale PE primary bus
  powerpc/eeh: Fix stale cached primary bus
  powerpc/pseries: Don't trace hcalls on offline CPUs
  powerpc: Fix dedotify for binutils >= 2.26
  powerpc/book3s_32: Fix build error with checkpoint restart

powerpc/eeh: Fix stale cached primary bus

2016-02-15T10:10:04+00:00

When PE is created, its primary bus is cached to pe->bus. At later
point, the cached primary bus is returned from eeh_pe_bus_get().
However, we could get stale cached primary bus and run into kernel
crash in one case: full hotplug as part of fenced PHB error recovery
releases all PCI busses under the PHB at unplugging time and recreate
them at plugging time. pe->bus is still dereferencing the PCI bus
that was released.

This adds another PE flag (EEH_PE_PRI_BUS) to represent the validity
of pe->bus. pe->bus is updated when its first child EEH device is
online and the flag is set. Before unplugging in full hotplug for
error recovery, the flag is cleared.

Fixes: 8cdb2833 ("powerpc/eeh: Trace PCI bus from PE")
Cc: stable@vger.kernel.org #v3.11+
Reported-by: Andrew Donnellan 
Reported-by: Pradipta Ghosh 
Signed-off-by: Gavin Shan 
Tested-by: Andrew Donnellan 
Signed-off-by: Michael Ellerman

Merge tag 'pci-v4.5-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

2016-01-21T19:52:16+00:00

Pull PCI updates from Bjorn Helgaas:
 "PCI changes for the v4.5 merge window:

  Enumeration:
   - Simplify config space size computation (Bjorn Helgaas)
   - Avoid iterating through ROM outside the resource window (Edward O'Callaghan)
   - Support PCIe devices with short cfg_size (Jason S. McMullan)
   - Add Netronome vendor and device IDs (Jason S. McMullan)
   - Limit config space size for Netronome NFP6000 family (Jason S. McMullan)
   - Add Netronome NFP4000 PF device ID (Simon Horman)
   - Limit config space size for Netronome NFP4000 (Simon Horman)
   - Print warnings for all invalid expansion ROM headers (Vladis Dronov)

  Resource management:
   - Fix minimum allocation address overwrite (Christoph Biedl)

  PCI device hotplug:
   - acpiphp_ibm: Fix null dereferences on null ibm_slot (Colin Ian King)
   - pciehp: Always protect pciehp_disable_slot() with hotplug mutex (Guenter Roeck)
   - shpchp: Constify hpc_ops structure (Julia Lawall)
   - ibmphp: Remove unneeded NULL test (Julia Lawall)

  Power management:
   - Make ASPM sysfs link_state_store() consistent with link_state_show() (Andy Lutomirski)

  Virtualization
   - Add function 1 DMA alias quirk for Lite-On/Plextor M6e/Marvell 88SS9183 (Tim Sander)

  MSI:
   - Remove empty pci_msi_init_pci_dev() (Bjorn Helgaas)
   - Mark PCIe/PCI (MSI) IRQ cascade handlers as IRQF_NO_THREAD (Grygorii Strashko)
   - Initialize MSI capability for all architectures (Guilherme G. Piccoli)
   - Relax msi_domain_alloc() to support parentless MSI irqdomains (Liu Jiang)

  ARM Versatile host bridge driver:
   - Remove unused pci_sys_data structures (Lorenzo Pieralisi)

  Broadcom iProc host bridge driver:
   - Hide CONFIG_PCIE_IPROC (Arnd Bergmann)
   - Do not use 0x in front of %pap (Dmitry V. Krivenok)
   - Update iProc PCIe device tree binding (Ray Jui)
   - Add PAXC interface support (Ray Jui)
   - Add iProc PCIe MSI device tree binding (Ray Jui)
   - Add iProc PCIe MSI support (Ray Jui)

  Freescale i.MX6 host bridge driver:
   - Use gpio_set_value_cansleep() (Fabio Estevam)
   - Add support for active-low reset GPIO (Petr Štetiar)

  HiSilicon host bridge driver:
   - Add support for HiSilicon Hip06 PCIe host controllers (Gabriele Paoloni)

  Intel VMD host bridge driver:
   - Export irq_domain_set_info() for module use (Keith Busch)
   - x86/PCI: Allow DMA ops specific to a PCI domain (Keith Busch)
   - Use 32 bit PCI domain numbers (Keith Busch)
   - Add driver for Intel Volume Management Device (VMD) (Keith Busch)

  Qualcomm host bridge driver:
   - Document PCIe devicetree bindings (Stanimir Varbanov)
   - Add Qualcomm PCIe controller driver (Stanimir Varbanov)
   - dts: apq8064: add PCIe devicetree node (Stanimir Varbanov)
   - dts: ifc6410: enable PCIe DT node for this board (Stanimir Varbanov)

  Renesas R-Car host bridge driver:
   - Add support for R-Car H3 to pcie-rcar (Harunobu Kurokawa)
   - Allow DT to override default window settings (Phil Edworthy)
   - Convert to DT resource parsing API (Phil Edworthy)
   - Revert "PCI: rcar: Build pcie-rcar.c only on ARM" (Phil Edworthy)
   - Remove unused pci_sys_data struct from pcie-rcar (Phil Edworthy)
   - Add runtime PM support to pcie-rcar (Phil Edworthy)
   - Add Gen2 PHY setup to pcie-rcar (Phil Edworthy)
   - Add gen2 fallback compatibility string for pci-rcar-gen2 (Simon Horman)
   - Add gen2 fallback compatibility string for pcie-rcar (Simon Horman)

  Synopsys DesignWare host bridge driver:
   - Simplify control flow (Bjorn Helgaas)
   - Make config accessor override checking symmetric (Bjorn Helgaas)
   - Ensure ATU is enabled before IO/conf space accesses (Stanimir Varbanov)

  Miscellaneous:
   - Add of_pci_get_host_bridge_resources() stub (Arnd Bergmann)
   - Check for PCI_HEADER_TYPE_BRIDGE equality, not bitmask (Bjorn Helgaas)
   - Fix all whitespace issues (Bogicevic Sasa)
   - x86/PCI: Simplify pci_bios_{read,write} (Geliang Tang)
   - Use to_pci_dev() instead of open-coding it (Geliang Tang)
   - Use kobj_to_dev() instead of open-coding it (Geliang Tang)
   - Use list_for_each_entry() to simplify code (Geliang Tang)
   - Fix typos in  (Thomas Petazzoni)
   - x86/PCI: Clarify AMD Fam10h config access restrictions comment (Tomasz Nowicki)"

* tag 'pci-v4.5-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (58 commits)
  PCI: Add function 1 DMA alias quirk for Lite-On/Plextor M6e/Marvell 88SS9183
  PCI: Limit config space size for Netronome NFP4000
  PCI: Add Netronome NFP4000 PF device ID
  x86/PCI: Add driver for Intel Volume Management Device (VMD)
  PCI/AER: Use 32 bit PCI domain numbers
  x86/PCI: Allow DMA ops specific to a PCI domain
  irqdomain: Export irq_domain_set_info() for module use
  PCI: host: Add of_pci_get_host_bridge_resources() stub
  genirq/MSI: Relax msi_domain_alloc() to support parentless MSI irqdomains
  PCI: rcar: Add Gen2 PHY setup to pcie-rcar
  PCI: rcar: Add runtime PM support to pcie-rcar
  PCI: designware: Make config accessor override checking symmetric
  PCI: ibmphp: Remove unneeded NULL test
  ARM: dts: ifc6410: enable PCIe DT node for this board
  ARM: dts: apq8064: add PCIe devicetree node
  PCI: hotplug: Use list_for_each_entry() to simplify code
  PCI: rcar: Remove unused pci_sys_data struct from pcie-rcar
  PCI: hisi: Add support for HiSilicon Hip06 PCIe host controllers
  PCI: Avoid iterating through memory outside the resource window
  PCI: acpiphp_ibm: Fix null dereferences on null ibm_slot
  ...

PCI: Check for PCI_HEADER_TYPE_BRIDGE equality, not bitmask

2015-12-11T01:38:06+00:00

Bit 7 of the "Header Type" register indicates a multi-function device when
set.  Bits 0-6 contain encoded values, where 0x1 indicates a PCI-PCI
bridge.  It is incorrect to test this as though it were a mask.

For example, while the PCI 3.0 spec only defines values 0x0, 0x1, and 0x2,
it's conceivable that a future spec could define 0x3 to mean something
else; then tests for "(hdr_type & 0x7f) & PCI_HEADER_TYPE_BRIDGE" would
incorrectly succeed for this new 0x3 header type.

Test bits 0-6 of the Header Type for equality with PCI_HEADER_TYPE_BRIDGE.

Signed-off-by: Bjorn Helgaas

Revert "powerpc/eeh: Don't unfreeze PHB PE after reset"

2015-12-09T03:05:10+00:00

This reverts commit 527d10ef3a315d3cb9dc098dacd61889a6c26439.

The reverted commit breaks cxlflash devices following an EEH reset (and
possibly other cxl devices, however this has not been tested).

The reverted commit changed the behaviour of eeh_reset_device() so that PHB
PEs are not unfrozen following the completion of the reset. This should not
be problematic, as no device resources should have been associated with the
PHB PE.

However, when attempting to load the cxlflash driver after a reset, the
driver attempts to read Vital Product Data through a call to
pci_read_vpd() (which is called on the physical cxl device, not on the
virtual AFU device). pci_read_vpd() in turn attempts to read from the cxl
device's config space. This fails, as the PE it's trying to read from is
still frozen. In turn, the driver gets an -ENODEV and fails to initialise.

It appears this issue only affects some parts of the VPD area, as "lspci
-vvv", which only reads a subset of the VPD bytes, is not broken by the
original patch.

At this stage, we don't fully understand why we're trying to read a frozen
PE, and we don't know how this affects other cxl devices. It is possible
that there is an underlying bug in the cxl driver or the powerpc CAPI
support code, or alternatively a bug in the PCI resource allocation/mapping
code that is incorrectly mapping resources to PE#0.

As such, this fix is incomplete, however it is necessary to prevent a
serious regression in CAPI support.

In the meantime, revert the commit, especially as it was intended to be a
non-functional change.

Cc: Gavin Shan 
Cc: Ian Munsie 
Cc: Daniel Axtens 
Signed-off-by: Andrew Donnellan 
Signed-off-by: Michael Ellerman

powerpc/eeh: Force reset on fenced PHB

2015-10-21T09:41:43+00:00

On fenced PHB, the error handlers in the drivers of its subordinate
devices could return PCI_ERS_RESULT_CAN_RECOVER, indicating no reset
will be issued during the recovery. It's conflicting with the fact
that fenced PHB won't be recovered without reset.

This limits the return value from the error handlers in the drivers
of the fenced PHB's subordinate devices to PCI_ERS_RESULT_NEED_NONE
or PCI_ERS_RESULT_NEED_RESET, to ensure reset will be issued during
recovery.

Signed-off-by: Gavin Shan 
Reviewed-by: Daniel Axtens 
Signed-off-by: Michael Ellerman