@@ -159,29 +159,17 @@ 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;
+ enum pci_bus_speed speed;
+ const char *speed_str;
int err;
- const char *speed;
- err = pcie_capability_read_dword(pci_dev, PCI_EXP_LNKCAP, &linkcap);
+ err = pcie_get_speed_cap(pci_dev, &speed);
if (err)
return -EINVAL;
- switch (linkcap & PCI_EXP_LNKCAP_SLS) {
- 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";
- }
+ speed_str = PCIE_SPEED2STR(speed);
- return sprintf(buf, "%s\n", speed);
+ return sprintf(buf, "%s\n", speed_str);
}
static DEVICE_ATTR_RO(max_link_speed);
@@ -5164,6 +5164,48 @@ int pcie_get_minimum_link(struct pci_dev *dev, enum pci_bus_speed *speed,
EXPORT_SYMBOL(pcie_get_minimum_link);
/**
+ * pcie_get_speed_cap - queries for the PCI device's link speed capability
+ * @dev: PCI device to query
+ * @speed: storage for link speed
+ *
+ * This function queries the PCI device speed capability.
+ */
+int pcie_get_speed_cap(struct pci_dev *dev, enum pci_bus_speed *speed)
+{
+ u32 lnkcap;
+ int err1, err2;
+
+ *speed = PCI_SPEED_UNKNOWN;
+
+ err1 = pcie_capability_read_dword(dev, PCI_EXP_LNKCAP,
+ &lnkcap);
+ if (!err1 && lnkcap) {
+ if (lnkcap & PCI_EXP_LNKCAP_SLS_8_0GB)
+ *speed = PCIE_SPEED_8_0GT;
+ else if (lnkcap & PCI_EXP_LNKCAP_SLS_5_0GB)
+ *speed = PCIE_SPEED_5_0GT;
+ else if (lnkcap & PCI_EXP_LNKCAP_SLS_2_5GB)
+ *speed = PCIE_SPEED_2_5GT;
+ return 0;
+ }
+
+ err2 = pcie_capability_read_dword(dev, PCI_EXP_LNKCAP2,
+ &lnkcap);
+ if (!err2 && lnkcap) { /* PCIe r3.0-compliant */
+ if (lnkcap & PCI_EXP_LNKCAP2_SLS_8_0GB)
+ *speed = PCIE_SPEED_8_0GT;
+ else if (lnkcap & PCI_EXP_LNKCAP2_SLS_5_0GB)
+ *speed = PCIE_SPEED_5_0GT;
+ else if (lnkcap & PCI_EXP_LNKCAP2_SLS_2_5GB)
+ *speed = PCIE_SPEED_2_5GT;
+ return 0;
+ }
+
+ return err1 ? err1 : err2;
+}
+EXPORT_SYMBOL(pcie_get_speed_cap);
+
+/**
* 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
@@ -259,6 +259,12 @@ enum pci_bus_speed {
PCI_SPEED_UNKNOWN = 0xff,
};
+#define PCIE_SPEED2STR(speed) \
+ ((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")
+
struct pci_cap_saved_data {
u16 cap_nr;
bool cap_extended;
@@ -1077,6 +1083,7 @@ static inline int pci_is_managed(struct pci_dev *pdev)
int pcie_set_mps(struct pci_dev *dev, int mps);
int pcie_get_minimum_link(struct pci_dev *dev, enum pci_bus_speed *speed,
enum pcie_link_width *width);
+int pcie_get_speed_cap(struct pci_dev *dev, enum pci_bus_speed *speed);
int pcie_flr(struct pci_dev *dev);
int __pci_reset_function_locked(struct pci_dev *dev);
int pci_reset_function(struct pci_dev *dev);
pcie_get_speed_cap() implements the logic for querying a PCI device's maximum speed capability. Change max_link_speed_show() function to use pcie_get_speed_cap(). Signed-off-by: Tal Gilboa <talgi@mellanox.com> --- drivers/pci/pci-sysfs.c | 22 +++++----------------- drivers/pci/pci.c | 42 ++++++++++++++++++++++++++++++++++++++++++ include/linux/pci.h | 7 +++++++ 3 files changed, 54 insertions(+), 17 deletions(-)