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| author |   Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> | 2020-03-23 17:26:07 -0700 |
|---|---|---|
| committer |   Bjorn Helgaas <bhelgaas@google.com> | 2020-03-28 13:19:04 -0500 |
| commit | ac1c8e35a3262d04cc81b07fac6480a3539e3b0f (patch) | |
| tree | 503f40fea8a536d0ffa31ceb3c93f145ada48a4a /include/linux/pci.h | |
| parent | PCI/DPC: Expose dpc_process_error(), dpc_reset_link() for use by EDR (diff) | |
| download | linux-dev-ac1c8e35a3262d04cc81b07fac6480a3539e3b0f.tar.xz linux-dev-ac1c8e35a3262d04cc81b07fac6480a3539e3b0f.zip | |
PCI/DPC: Add Error Disconnect Recover (EDR) support
Error Disconnect Recover (EDR) is a feature that allows ACPI firmware to
notify OSPM that a device has been disconnected due to an error condition
(ACPI v6.3, sec 5.6.6). OSPM advertises its support for EDR on PCI devices
via _OSC (see [1], sec 4.5.1, table 4-4). The OSPM EDR notify handler
should invalidate software state associated with disconnected devices and
may attempt to recover them. OSPM communicates the status of recovery to
the firmware via _OST (sec 6.3.5.2).
For PCIe, firmware may use Downstream Port Containment (DPC) to support
EDR. Per [1], sec 4.5.1, table 4-6, even if firmware has retained control
of DPC, OSPM may read/write DPC control and status registers during the EDR
notification processing window, i.e., from the time it receives an EDR
notification until it clears the DPC Trigger Status.
Note that per [1], sec 4.5.1 and 4.5.2.4,
1. If the OS supports EDR, it should advertise that to firmware by
setting OSC_PCI_EDR_SUPPORT in _OSC Support.
2. If the OS sets OSC_PCI_EXPRESS_DPC_CONTROL in _OSC Control to request
control of the DPC capability, it must also set OSC_PCI_EDR_SUPPORT in
_OSC Support.
Add an EDR notify handler to attempt recovery.
[1] Downstream Port Containment Related Enhancements ECN, Jan 28, 2019,
affecting PCI Firmware Specification, Rev. 3.2
https://members.pcisig.com/wg/PCI-SIG/document/12888
[bhelgaas: squash add/enable patches into one]
Link: https://lore.kernel.org/r/90f91fe6d25c13f9d2255d2ce97ca15be307e1bb.1585000084.git.sathyanarayanan.kuppuswamy@linux.intel.com
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Len Brown <lenb@kernel.org>
Diffstat (limited to 'include/linux/pci.h')
| -rw-r--r-- | include/linux/pci.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/pci.h b/include/linux/pci.h index a0b7e7a53741..7ed7c088c952 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -515,6 +515,7 @@ struct pci_host_bridge { unsigned int native_shpc_hotplug:1; /* OS may use SHPC hotplug */ unsigned int native_pme:1; /* OS may use PCIe PME */ unsigned int native_ltr:1; /* OS may use PCIe LTR */ + unsigned int native_dpc:1; /* OS may use PCIe DPC */ unsigned int preserve_config:1; /* Preserve FW resource setup */ /* Resource alignment requirements */ |