diff options
| -rw-r--r-- | drivers/pci/pci-sysfs.c | 28 | ||||
| -rw-r--r-- | drivers/pci/pci.c | 44 | ||||
| -rw-r--r-- | drivers/pci/pci.h | 10 |
3 files changed, 56 insertions, 26 deletions
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index 7dc5be545d18..c2ea05fbbf1d 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -158,33 +158,9 @@ static DEVICE_ATTR_RO(resource); static ssize_t max_link_speed_show(struct device *dev, struct device_attribute *attr, char *buf) { - struct pci_dev *pci_dev = to_pci_dev(dev); - u32 linkcap; - int err; - const char *speed; - - err = pcie_capability_read_dword(pci_dev, PCI_EXP_LNKCAP, &linkcap); - if (err) - return -EINVAL; - - switch (linkcap & PCI_EXP_LNKCAP_SLS) { - case PCI_EXP_LNKCAP_SLS_16_0GB: - speed = "16 GT/s"; - break; - case PCI_EXP_LNKCAP_SLS_8_0GB: - speed = "8 GT/s"; - break; - case PCI_EXP_LNKCAP_SLS_5_0GB: - speed = "5 GT/s"; - break; - case PCI_EXP_LNKCAP_SLS_2_5GB: - speed = "2.5 GT/s"; - break; - default: - speed = "Unknown speed"; - } + struct pci_dev *pdev = to_pci_dev(dev); - return sprintf(buf, "%s\n", speed); + return sprintf(buf, "%s\n", PCIE_SPEED2STR(pcie_get_speed_cap(pdev))); } static DEVICE_ATTR_RO(max_link_speed); diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index f6a4dd10d9b0..b29d3436ee9f 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -5147,6 +5147,50 @@ int pcie_get_minimum_link(struct pci_dev *dev, enum pci_bus_speed *speed, EXPORT_SYMBOL(pcie_get_minimum_link); /** + * pcie_get_speed_cap - query for the PCI device's link speed capability + * @dev: PCI device to query + * + * Query the PCI device speed capability. Return the maximum link speed + * supported by the device. + */ +enum pci_bus_speed pcie_get_speed_cap(struct pci_dev *dev) +{ + u32 lnkcap2, lnkcap; + + /* + * PCIe r4.0 sec 7.5.3.18 recommends using the Supported Link + * Speeds Vector in Link Capabilities 2 when supported, falling + * back to Max Link Speed in Link Capabilities otherwise. + */ + pcie_capability_read_dword(dev, PCI_EXP_LNKCAP2, &lnkcap2); + if (lnkcap2) { /* PCIe r3.0-compliant */ + if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_16_0GB) + return PCIE_SPEED_16_0GT; + else if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_8_0GB) + return PCIE_SPEED_8_0GT; + else if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_5_0GB) + return PCIE_SPEED_5_0GT; + else if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_2_5GB) + return PCIE_SPEED_2_5GT; + return PCI_SPEED_UNKNOWN; + } + + pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, &lnkcap); + if (lnkcap) { + if (lnkcap & PCI_EXP_LNKCAP_SLS_16_0GB) + return PCIE_SPEED_16_0GT; + else if (lnkcap & PCI_EXP_LNKCAP_SLS_8_0GB) + return PCIE_SPEED_8_0GT; + else if (lnkcap & PCI_EXP_LNKCAP_SLS_5_0GB) + return PCIE_SPEED_5_0GT; + else if (lnkcap & PCI_EXP_LNKCAP_SLS_2_5GB) + return PCIE_SPEED_2_5GT; + } + + return PCI_SPEED_UNKNOWN; +} + +/** * pci_select_bars - Make BAR mask from the type of resource * @dev: the PCI device for which BAR mask is made * @flags: resource type mask to be selected diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index fcd81911b127..1186d8be6055 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -253,6 +253,16 @@ bool pci_bus_clip_resource(struct pci_dev *dev, int idx); void pci_reassigndev_resource_alignment(struct pci_dev *dev); void pci_disable_bridge_window(struct pci_dev *dev); +/* PCIe link information */ +#define PCIE_SPEED2STR(speed) \ + ((speed) == PCIE_SPEED_16_0GT ? "16 GT/s" : \ + (speed) == PCIE_SPEED_8_0GT ? "8 GT/s" : \ + (speed) == PCIE_SPEED_5_0GT ? "5 GT/s" : \ + (speed) == PCIE_SPEED_2_5GT ? "2.5 GT/s" : \ + "Unknown speed") + +enum pci_bus_speed pcie_get_speed_cap(struct pci_dev *dev); + /* Single Root I/O Virtualization */ struct pci_sriov { int pos; /* Capability position */ |