Except for Endpoints, we enable PTM at enumeration-time. Previously we did
not account for the fact that Switch Downstream Ports are not permitted to
have a PTM capability; their PTM behavior is controlled by the Upstream
Port (PCIe r5.0, sec 7.9.16). Since Downstream Ports don't have a PTM
capability, we did not mark them as "ptm_enabled", which meant that
pci_enable_ptm() on an Endpoint failed because there was no PTM path to it.
Mark Downstream Ports as "ptm_enabled" if their Upstream Port has PTM
enabled.
Fixes: eec097d431 ("PCI: Add pci_enable_ptm() for drivers to enable PTM on endpoints")
Reported-by: Aditya Paluri <Venkata.AdityaPaluri@synopsys.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
The granularity message has an extra "d":
pci 0000:02:00.0: PTM enabled, 4dns granularity
Remove the "d" so the message is simply "PTM enabled, 4ns granularity".
Fixes: 8b2ec318ee ("PCI: Add PTM clock granularity information")
Link: https://lore.kernel.org/r/20191106222420.10216-2-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andrew Murray <andrew.murray@arm.com>
Cc: Jonathan Yong <jonathan.yong@intel.com>
* pci/spdx:
PCI: Add SPDX GPL-2.0+ to replace implicit GPL v2 or later statement
PCI: Add SPDX GPL-2.0+ to replace GPL v2 or later boilerplate
PCI: Add SPDX GPL-2.0 to replace COPYING boilerplate
PCI: Add SPDX GPL-2.0 to replace GPL v2 boilerplate
PCI: Add SPDX GPL-2.0 when no license was specified
Add SPDX GPL-2.0 to all PCI files that specified the GPL version 2 license.
Remove the boilerplate GPL version 2 language, relying on the assertion in
b24413180f ("License cleanup: add SPDX GPL-2.0 license identifier to
files with no license") that the SPDX identifier may be used instead of the
full boilerplate text.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add PCI-specific dev_printk() wrappers and use them to simplify the code
slightly. No functional change intended.
Signed-off-by: Frederick Lawler <fred@fredlawl.com>
[bhelgaas: squash into one patch]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
The PTM Control register (PCIe r3.1, sec 7.32.3) contains an Effective
Granularity field:
This provides information relating to the expected accuracy of the PTM
clock, but does not otherwise affect the PTM mechanism.
Set the Effective Granularity based on the PTM Root and any intervening PTM
Time Sources.
This does not set Effective Granularity for Root Complex Integrated
Endpoints because I don't know how to figure out clock granularity for
them. The spec says:
... system software must set [Effective Granularity] to the value
reported in the Local Clock Granularity field by the associated PTM
Time Source.
but I don't know how to identify the associated PTM Time Source. Normally
it's the upstream bridge, but an integrated endpoint has no upstream
bridge.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Add an pci_enable_ptm() interface so drivers can enable PTM.
The PCI core enables PTM on PTM Roots and switches automatically, but we
don't enable PTM on endpoints unless a driver requests it.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
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 <jonathan.yong@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
