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| author | Tal Gilboa <talgi@mellanox.com> | 2018-03-30 08:24:36 -0500 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2018-03-30 15:33:38 -0500 |
| commit | c70b65fb7f121da7d01f62588ce6abb4741f513f (patch) | |
| tree | 383cdda6cad94b1ef9b3f116382221c3a379089e | |
| parent | 6cf57be0f78e289aaf236f8bc55c40ea6c422c75 (diff) | |
| download | linux-c70b65fb7f121da7d01f62588ce6abb4741f513f.tar.gz linux-c70b65fb7f121da7d01f62588ce6abb4741f513f.tar.xz | |
PCI: Add pcie_get_width_cap() to find max supported link width
Add pcie_get_width_cap() to find the max link width supported by a device.
Change max_link_width_show() to use pcie_get_width_cap().
Signed-off-by: Tal Gilboa <talgi@mellanox.com>
[bhelgaas: return width directly instead of error and *width, don't export
outside drivers/pci]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
| -rw-r--r-- | drivers/pci/pci-sysfs.c | 10 | ||||
| -rw-r--r-- | drivers/pci/pci.c | 18 | ||||
| -rw-r--r-- | drivers/pci/pci.h | 1 |
3 files changed, 21 insertions, 8 deletions
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index c2ea05fbbf1d..63d0952684fb 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -167,15 +167,9 @@ static DEVICE_ATTR_RO(max_link_speed); 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; - int err; - - err = pcie_capability_read_dword(pci_dev, PCI_EXP_LNKCAP, &linkcap); - if (err) - return -EINVAL; + struct pci_dev *pdev = to_pci_dev(dev); - return sprintf(buf, "%u\n", (linkcap & PCI_EXP_LNKCAP_MLW) >> 4); + return sprintf(buf, "%u\n", pcie_get_width_cap(pdev)); } static DEVICE_ATTR_RO(max_link_width); diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index b29d3436ee9f..43075be79388 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -5191,6 +5191,24 @@ enum pci_bus_speed pcie_get_speed_cap(struct pci_dev *dev) } /** + * pcie_get_width_cap - query for the PCI device's link width capability + * @dev: PCI device to query + * + * Query the PCI device width capability. Return the maximum link width + * supported by the device. + */ +enum pcie_link_width pcie_get_width_cap(struct pci_dev *dev) +{ + u32 lnkcap; + + pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, &lnkcap); + if (lnkcap) + return (lnkcap & PCI_EXP_LNKCAP_MLW) >> 4; + + return PCIE_LNK_WIDTH_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 1186d8be6055..66738f1050c0 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -262,6 +262,7 @@ void pci_disable_bridge_window(struct pci_dev *dev); "Unknown speed") enum pci_bus_speed pcie_get_speed_cap(struct pci_dev *dev); +enum pcie_link_width pcie_get_width_cap(struct pci_dev *dev); /* Single Root I/O Virtualization */ struct pci_sriov { |