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-rw-r--r--drivers/pci/probe.c18
-rw-r--r--include/linux/pci.h1
2 files changed, 19 insertions, 0 deletions
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 6675a7a1b9fc..96dcd7b8303b 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -973,6 +973,8 @@ void set_pcie_port_type(struct pci_dev *pdev)
{
int pos;
u16 reg16;
+ int type;
+ struct pci_dev *parent;
pos = pci_find_capability(pdev, PCI_CAP_ID_EXP);
if (!pos)
@@ -982,6 +984,22 @@ void set_pcie_port_type(struct pci_dev *pdev)
pdev->pcie_flags_reg = reg16;
pci_read_config_word(pdev, pos + PCI_EXP_DEVCAP, &reg16);
pdev->pcie_mpss = reg16 & PCI_EXP_DEVCAP_PAYLOAD;
+
+ /*
+ * A Root Port is always the upstream end of a Link. No PCIe
+ * component has two Links. Two Links are connected by a Switch
+ * that has a Port on each Link and internal logic to connect the
+ * two Ports.
+ */
+ type = pci_pcie_type(pdev);
+ if (type == PCI_EXP_TYPE_ROOT_PORT)
+ pdev->has_secondary_link = 1;
+ else if (type == PCI_EXP_TYPE_UPSTREAM ||
+ type == PCI_EXP_TYPE_DOWNSTREAM) {
+ parent = pci_upstream_bridge(pdev);
+ if (!parent->has_secondary_link)
+ pdev->has_secondary_link = 1;
+ }
}
void set_pcie_hotplug_bridge(struct pci_dev *pdev)
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 353db8dc4c6e..1989f6dc9618 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -355,6 +355,7 @@ struct pci_dev {
unsigned int broken_intx_masking:1;
unsigned int io_window_1k:1; /* Intel P2P bridge 1K I/O windows */
unsigned int irq_managed:1;
+ unsigned int has_secondary_link:1;
pci_dev_flags_t dev_flags;
atomic_t enable_cnt; /* pci_enable_device has been called */