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Diffstat (limited to 'drivers/pci')
-rw-r--r--drivers/pci/probe.c43
-rw-r--r--drivers/pci/quirks.c11
2 files changed, 54 insertions, 0 deletions
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index c31310db0404..e6a917b4acd3 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1762,6 +1762,48 @@ static void pci_configure_extended_tags(struct pci_dev *dev)
PCI_EXP_DEVCTL_EXT_TAG);
}
+/**
+ * pcie_relaxed_ordering_enabled - Probe for PCIe relaxed ordering enable
+ * @dev: PCI device to query
+ *
+ * Returns true if the device has enabled relaxed ordering attribute.
+ */
+bool pcie_relaxed_ordering_enabled(struct pci_dev *dev)
+{
+ u16 v;
+
+ pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &v);
+
+ return !!(v & PCI_EXP_DEVCTL_RELAX_EN);
+}
+EXPORT_SYMBOL(pcie_relaxed_ordering_enabled);
+
+static void pci_configure_relaxed_ordering(struct pci_dev *dev)
+{
+ struct pci_dev *root;
+
+ /* PCI_EXP_DEVICE_RELAX_EN is RsvdP in VFs */
+ if (dev->is_virtfn)
+ return;
+
+ if (!pcie_relaxed_ordering_enabled(dev))
+ return;
+
+ /*
+ * For now, we only deal with Relaxed Ordering issues with Root
+ * Ports. Peer-to-Peer DMA is another can of worms.
+ */
+ root = pci_find_pcie_root_port(dev);
+ if (!root)
+ return;
+
+ if (root->dev_flags & PCI_DEV_FLAGS_NO_RELAXED_ORDERING) {
+ pcie_capability_clear_word(dev, PCI_EXP_DEVCTL,
+ PCI_EXP_DEVCTL_RELAX_EN);
+ dev_info(&dev->dev, "Disable Relaxed Ordering because the Root Port didn't support it\n");
+ }
+}
+
static void pci_configure_device(struct pci_dev *dev)
{
struct hotplug_params hpp;
@@ -1769,6 +1811,7 @@ static void pci_configure_device(struct pci_dev *dev)
pci_configure_mps(dev);
pci_configure_extended_tags(dev);
+ pci_configure_relaxed_ordering(dev);
memset(&hpp, 0, sizeof(hpp));
ret = pci_get_hp_params(dev, &hpp);
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 6967c6b4cf6b..61b59bfa7bfc 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -4016,6 +4016,17 @@ DECLARE_PCI_FIXUP_CLASS_EARLY(0x1797, 0x6869, PCI_CLASS_NOT_DEFINED, 8,
quirk_tw686x_class);
/*
+ * Some devices have problems with Transaction Layer Packets with the Relaxed
+ * Ordering Attribute set. Such devices should mark themselves and other
+ * Device Drivers should check before sending TLPs with RO set.
+ */
+static void quirk_relaxedordering_disable(struct pci_dev *dev)
+{
+ dev->dev_flags |= PCI_DEV_FLAGS_NO_RELAXED_ORDERING;
+ dev_info(&dev->dev, "Disable Relaxed Ordering Attributes to avoid PCIe Completion erratum\n");
+}
+
+/*
* Per PCIe r3.0, sec 2.2.9, "Completion headers must supply the same
* values for the Attribute as were supplied in the header of the
* corresponding Request, except as explicitly allowed when IDO is used."