int ret;
if (!pci_is_pcie(dev))
- return;
+ return 0;
- ret = pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &dev_cap);
+ ret = pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &cap);
if (ret)
- return;
+ return 0;
+
+ if (!(cap & PCI_EXP_DEVCAP_EXT_TAG))
+ return 0;
+
+ ret = pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &ctl);
+ if (ret)
+ return 0;
+
+ host = pci_find_host_bridge(dev->bus);
+ if (!host)
+ return 0;
- if (dev_cap & PCI_EXP_DEVCAP_EXT_TAG)
+ /*
+ * If some device in the hierarchy doesn't handle Extended Tags
+ * correctly, make sure they're disabled.
+ */
+ if (host->no_ext_tags) {
+ if (ctl & PCI_EXP_DEVCTL_EXT_TAG) {
+ dev_info(&dev->dev, "disabling Extended Tags\n");
+ pcie_capability_clear_word(dev, PCI_EXP_DEVCTL,
+ PCI_EXP_DEVCTL_EXT_TAG);
+ }
+ return 0;
+ }
+
+ if (!(ctl & PCI_EXP_DEVCTL_EXT_TAG)) {
+ dev_info(&dev->dev, "enabling Extended Tags\n");
pcie_capability_set_word(dev, PCI_EXP_DEVCTL,
PCI_EXP_DEVCTL_EXT_TAG);
+ }
+ return 0;
}
+/**
+ * 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;
int ret;
pci_configure_mps(dev);
- pci_configure_extended_tags(dev);
+ pci_configure_extended_tags(dev, NULL);
+ pci_configure_relaxed_ordering(dev);
memset(&hpp, 0, sizeof(hpp));
ret = pci_get_hp_params(dev, &hpp);