linux.git/drivers/pci/probe.c, branch v4.9

PCI: Set Read Completion Boundary to 128 iff Root Port supports it (_HPX)

2016-11-23T22:23:55+00:00

Per PCIe spec r3.0, sec 2.3.1.1, the Read Completion Boundary (RCB)
determines the naturally aligned address boundaries on which a Read Request
may be serviced with multiple Completions:

  - For a Root Complex, RCB is 64 bytes or 128 bytes
    This value is reported in the Link Control Register

    Note: Bridges and Endpoints may implement a corresponding command bit
    which may be set by system software to indicate the RCB value for the
    Root Complex, allowing the Bridge/Endpoint to optimize its behavior
    when the Root Complex’s RCB is 128 bytes.

  - For all other system elements, RCB is 128 bytes

Per sec 7.8.7, if a Root Port only supports a 64-byte RCB, the RCB of all
downstream devices must be clear, indicating an RCB of 64 bytes.  If the
Root Port supports a 128-byte RCB, we may optionally set the RCB of
downstream devices so they know they can generate larger Completions.

Some BIOSes supply an _HPX that tells us to set RCB, even though the Root
Port doesn't have RCB set, which may lead to Malformed TLP errors if the
Endpoint generates completions larger than the Root Port can handle.

The IBM x3850 X6 with BIOS version -[A8E120CUS-1.30]- 08/22/2016 supplies
such an _HPX and a Mellanox MT27500 ConnectX-3 device fails to initialize:

  mlx4_core 0000:41:00.0: command 0xfff timed out (go bit not cleared)
  mlx4_core 0000:41:00.0: device is going to be reset
  mlx4_core 0000:41:00.0: Failed to obtain HW semaphore, aborting
  mlx4_core 0000:41:00.0: Fail to reset HCA
  ------------[ cut here ]------------
  kernel BUG at drivers/net/ethernet/mellanox/mlx4/catas.c:193!

After 6cd33649fa83 ("PCI: Add pci_configure_device() during enumeration")
and 7a1562d4f2d0 ("PCI: Apply _HPX Link Control settings to all devices
with a link"), we apply _HPX settings to *all* devices, not just those
hot-added after boot.

Before 7a1562d4f2d0, we didn't touch the Mellanox RCB, and the device
worked.  After 7a1562d4f2d0, we set its RCB to 128, and it failed.

Set the RCB to 128 iff the Root Port supports a 128-byte RCB.  Otherwise,
set RCB to 64 bytes.  This effectively ignores what _HPX tells us about
RCB.

Note that this change only affects _HPX handling.  If we have no _HPX, this
does nothing with RCB.

[bhelgaas: changelog, clear RCB if not set for Root Port]
Fixes: 6cd33649fa83 ("PCI: Add pci_configure_device() during enumeration")
Fixes: 7a1562d4f2d0 ("PCI: Apply _HPX Link Control settings to all devices with a link")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=187781
Tested-by: Frank Danapfel 
Signed-off-by: Johannes Thumshirn 
Signed-off-by: Bjorn Helgaas 
Acked-by: Myron Stowe 
CC: stable@vger.kernel.org	# v3.18+

Merge branch 'pci/aer' into next

2016-10-03T14:42:57+00:00

* pci/aer:
  PCI/AER: Fix aer_probe() kernel-doc comment
  PCI/AER: Cache capability position
  PCI/AER: Avoid memory allocation in interrupt handling path
  ACPI / APEI: Send correct severity to calculate AER severity
  PCI/AER: Remove duplicate AER severity translation
  PCI/AER: Remove aerdriver.forceload kernel parameter
  PCI/AER: Remove aerdriver.nosourceid kernel parameter
  x86/PCI: VMD: Add quirk for AER to ignore source ID
  PCI/AER: Add bus flag to skip source ID matching

Conflicts:
	drivers/pci/probe.c

PCI/AER: Cache capability position

2016-09-27T21:01:49+00:00

Save the position of the error reporting capability so it doesn't need to
be rediscovered during error handling.

Signed-off-by: Keith Busch 
Signed-off-by: Bjorn Helgaas 
CC: Lukas Wunner

PCI: Add Precision Time Measurement (PTM) support

2016-08-15T18:44:08+00:00

Add Precision Time Measurement (PTM) support (see PCIe r3.1, sec 6.22).

Enable PTM on PTM Root devices and switch ports.  This does not enable PTM
on endpoints.

There currently are no PTM-capable devices on the market, but it is
expected to be supported by the Intel Apollo Lake platform.

[bhelgaas: complete rework]
Signed-off-by: Jonathan Yong 
Signed-off-by: Bjorn Helgaas

Merge branches 'pci/aspm', 'pci/dpc', 'pci/hotplug', 'pci/misc', 'pci/msi', 'pci/pm' and 'pci/virtualization' into next

2016-08-01T17:23:31+00:00

* pci/aspm:
  PCI/ASPM: Remove redundant check of pcie_set_clkpm

* pci/dpc:
  PCI: Remove DPC tristate module option
  PCI: Bind DPC to Root Ports as well as Downstream Ports
  PCI: Fix whitespace in struct dpc_dev
  PCI: Convert Downstream Port Containment driver to use devm_* functions

* pci/hotplug:
  PCI: Allow additional bus numbers for hotplug bridges

* pci/misc:
  PCI: Include  for isa_dma_bridge_buggy
  PCI: Make bus_attr_resource_alignment static
  MAINTAINERS: Add file patterns for PCI device tree bindings
  PCI: Fix comment typo

* pci/msi:
  PCI/MSI: irqchip: Fix PCI_MSI dependencies

* pci/pm:
  PCI: pciehp: Ignore interrupts during D3cold
  PCI: Document connection between pci_power_t and hardware PM capability
  PCI: Add runtime PM support for PCIe ports
  ACPI / hotplug / PCI: Runtime resume bridge before rescan
  PCI: Power on bridges before scanning new devices
  PCI: Put PCIe ports into D3 during suspend
  PCI: Don't clear d3cold_allowed for PCIe ports
  PCI / PM: Enforce type casting for pci_power_t

* pci/virtualization:
  PCI: Add ACS quirk for Solarflare SFC9220
  PCI: Add DMA alias quirk for Adaptec 3805
  PCI: Mark Atheros AR9485 and QCA9882 to avoid bus reset
  PCI: Add function 1 DMA alias quirk for Marvell 88SE9182

PCI: Allow additional bus numbers for hotplug bridges

2016-07-25T17:52:47+00:00

A user may hot add a switch requiring more than one bus to enumerate.  This
previously required a system reboot if BIOS did not sufficiently pad the
bus resource, which they frequently don't do.

Add a kernel parameter so a user can specify the minimum number of bus
numbers to reserve for a hotplug bridge's subordinate buses so rebooting
won't be necessary.

The default is 1, which is equivalent to previous behavior.

Signed-off-by: Keith Busch 
Signed-off-by: Bjorn Helgaas

PCI: Power on bridges before scanning new devices

2016-06-13T19:57:58+00:00

When a PCI device is removed through sysfs interface, the upstream bridge
(PCIe port) can be runtime suspended if it was the last device on that bus.
Now, if the bridge is in D3 we cannot find devices below the bridge
anymore.  For example following fails to find the removed device again:

  # echo 1 > /sys/bus/pci/devices/0000:00:01.0/0000:01:00.0/remove
  # echo 1 > /sys/bus/pci/devices/0000:00:01.0/rescan

Where 0000:00:01.0 is the bridge device.

In order to be able to rescan devices below the bridge add
pm_runtime_get_sync()/pm_runtime_put() calls to pci_scan_bridge().  This
should keep bridges powered on while their children devices are being
scanned.

Reported-by: Peter Wu 
Signed-off-by: Mika Westerberg 
Signed-off-by: Bjorn Helgaas 
Acked-by: Rafael J. Wysocki

PCI: Refactor pci_bus_assign_domain_nr() for CONFIG_PCI_DOMAINS_GENERIC

2016-06-10T23:28:12+00:00

Instead of assigning bus->domain_nr inside pci_bus_assign_domain_nr(),
return the domain and let the caller do the assignment.  Rename
pci_bus_assign_domain_nr() to pci_bus_find_domain_nr() to reflect this.

No functional change intended.

[bhelgaas: changelog]
Signed-off-by: Tomasz Nowicki 
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Lorenzo Pieralisi

Merge branches 'pci/hotplug' and 'pci/resource' into next

2016-05-17T19:35:38+00:00

* pci/hotplug:
  PCI: Use cached copy of PCI_EXP_SLTCAP_HPC bit

* pci/resource:
  PCI: Disable all BAR sizing for devices with non-compliant BARs
  x86/PCI: Mark Broadwell-EP Home Agent 1 as having non-compliant BARs
  PCI: Identify Enhanced Allocation (EA) BAR Equivalent resources in sysfs

PCI: Disable all BAR sizing for devices with non-compliant BARs

2016-05-16T20:57:56+00:00

b84106b4e229 ("PCI: Disable IO/MEM decoding for devices with non-compliant
BARs") disabled BAR sizing for BARs 0-5 of devices that don't comply with
the PCI spec.  But it didn't do anything for expansion ROM BARs, so we
still try to size them, resulting in warnings like this on Broadwell-EP:

  pci 0000:ff:12.0: BAR 6: failed to assign [mem size 0x00000001 pref]

Move the non-compliant BAR check from __pci_read_base() up to
pci_read_bases() so it applies to the expansion ROM BAR as well as
to BARs 0-5.

Note that direct callers of __pci_read_base(), like sriov_init(), will now
bypass this check.  We haven't had reports of devices with broken SR-IOV
BARs yet.

[bhelgaas: changelog]
Fixes: b84106b4e229 ("PCI: Disable IO/MEM decoding for devices with non-compliant BARs")
Signed-off-by: Prarit Bhargava 
Signed-off-by: Bjorn Helgaas 
CC: stable@vger.kernel.org
CC: Thomas Gleixner 
CC: Ingo Molnar 
CC: "H. Peter Anvin" 
CC: Andi Kleen