PCI: Add Downstream Port Containment driver
Add driver for the PCI Express Downstream Port Containment extended
capability. DPC is an optional capability to contain uncorrectable errors
below a port.
For more information on DPC, please see PCI Express Base Specification
Revision 4, section 7.31, or view the PCI-SIG DPC ECN here:
https://pcisig.com/sites/default/files/specification_documents/ECN_DPC_2012-02-09_finalized.pdf
When a DPC event is triggered, the hardware disables downstream links, so
the DPC driver schedules removal for all devices below this port. This may
happen concurrently with a PCIe hotplug driver if enabled. When all
downstream devices are removed and the link state transitions to disabled,
the DPC driver clears the DPC status and interrupt bits so the link may
retrain for a newly connected device.
[bhelgaas: clear (not set) DPC_CTL bits on remove, whitespace cleanup]
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Lukas Wunner <lukas@wunner.de>
diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h
index 61e95c1..4040951 100644
--- a/include/uapi/linux/pci_regs.h
+++ b/include/uapi/linux/pci_regs.h
@@ -947,4 +947,21 @@
#define PCI_TPH_CAP_ST_SHIFT 16 /* st table shift */
#define PCI_TPH_BASE_SIZEOF 12 /* size with no st table */
+/* Downstream Port Containment */
+#define PCI_EXP_DPC_CAP 4 /* DPC Capability */
+#define PCI_EXP_DPC_CAP_RP_EXT 0x20 /* Root Port Extensions for DPC */
+#define PCI_EXP_DPC_CAP_POISONED_TLP 0x40 /* Poisoned TLP Egress Blocking Supported */
+#define PCI_EXP_DPC_CAP_SW_TRIGGER 0x80 /* Software Triggering Supported */
+#define PCI_EXP_DPC_CAP_DL_ACTIVE 0x1000 /* ERR_COR signal on DL_Active supported */
+
+#define PCI_EXP_DPC_CTL 6 /* DPC control */
+#define PCI_EXP_DPC_CTL_EN_NONFATAL 0x02 /* Enable trigger on ERR_NONFATAL message */
+#define PCI_EXP_DPC_CTL_INT_EN 0x08 /* DPC Interrupt Enable */
+
+#define PCI_EXP_DPC_STATUS 8 /* DPC Status */
+#define PCI_EXP_DPC_STATUS_TRIGGER 0x01 /* Trigger Status */
+#define PCI_EXP_DPC_STATUS_INTERRUPT 0x08 /* Interrupt Status */
+
+#define PCI_EXP_DPC_SOURCE_ID 10 /* DPC Source Identifier */
+
#endif /* LINUX_PCI_REGS_H */