pcie_get_width_cap() implements the logic for querying a PCI device's maximum width capability. Change max_link_width_show() function to use pcie_get_width_cap(). Signed-off-by: Tal Gilboa <talgi@xxxxxxxxxxxx> --- drivers/pci/pci-sysfs.c | 6 +++--- drivers/pci/pci.c | 23 +++++++++++++++++++++++ include/linux/pci.h | 1 + 3 files changed, 27 insertions(+), 3 deletions(-) diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index c8b4854..ae30ba2 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -177,14 +177,14 @@ static ssize_t max_link_width_show(struct device *dev, struct device_attribute *attr, char *buf) { struct pci_dev *pci_dev = to_pci_dev(dev); - u32 linkcap; + enum pcie_link_width width; int err; - err = pcie_capability_read_dword(pci_dev, PCI_EXP_LNKCAP, &linkcap); + err = pcie_get_width_cap(pci_dev, &width); if (err) return -EINVAL; - return sprintf(buf, "%u\n", (linkcap & PCI_EXP_LNKCAP_MLW) >> 4); + return sprintf(buf, "%u\n", width); } static DEVICE_ATTR_RO(max_link_width); diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 7620cc9..48b9fd6 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -5206,6 +5206,29 @@ int pcie_get_speed_cap(struct pci_dev *dev, enum pci_bus_speed *speed) EXPORT_SYMBOL(pcie_get_speed_cap); /** + * pcie_get_width_cap - queries for the PCI device's link width capability. + * @dev: PCI device to query + * @width: storage for link width + * + * This function queries the PCI device width capability. + */ +int pcie_get_width_cap(struct pci_dev *dev, enum pcie_link_width *width) +{ + u32 lnkcap; + int err; + + *width = PCIE_LNK_WIDTH_UNKNOWN; + + err = pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, &lnkcap); + if (!err && lnkcap) + /* Shift start of width mask by 4 to get actual speed cap */ + *width = (lnkcap & PCI_EXP_LNKCAP_MLW) >> 4; + + return err; +} +EXPORT_SYMBOL(pcie_get_width_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 diff --git a/include/linux/pci.h b/include/linux/pci.h index 54443e4..8242d3d 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1084,6 +1084,7 @@ static inline int pci_is_managed(struct pci_dev *pdev) 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_get_width_cap(struct pci_dev *dev, enum pcie_link_width *width); int pcie_flr(struct pci_dev *dev); int __pci_reset_function_locked(struct pci_dev *dev); int pci_reset_function(struct pci_dev *dev); -- 1.8.3.1