On Mon, Feb 06, 2023 at 01:51:01PM -0700, Dave Jiang wrote:
> Move the logic in current_link_width_show() to a common function and export
> that functiuon as pcie_get_width() to allow other drivers to to retrieve
> the current negotiated link width.
s/a common function and export that functiuon and export that functiuon as//
I don't see the module caller of this, so not clear on why it needs to
be exported.
> Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
> ---
> drivers/pci/pci-sysfs.c | 9 +--------
> drivers/pci/pci.c | 20 ++++++++++++++++++++
> include/linux/pci.h | 1 +
> 3 files changed, 22 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
> index 0217bb5ca8fa..139096c39380 100644
> --- a/drivers/pci/pci-sysfs.c
> +++ b/drivers/pci/pci-sysfs.c
> @@ -215,15 +215,8 @@ static ssize_t current_link_width_show(struct device *dev,
> struct device_attribute *attr, char *buf)
> {
> struct pci_dev *pci_dev = to_pci_dev(dev);
> - u16 linkstat;
> - int err;
>
> - err = pcie_capability_read_word(pci_dev, PCI_EXP_LNKSTA, &linkstat);
> - if (err)
> - return -EINVAL;
> -
> - return sysfs_emit(buf, "%u\n",
> - (linkstat & PCI_EXP_LNKSTA_NLW) >> PCI_EXP_LNKSTA_NLW_SHIFT);
> + return sysfs_emit(buf, "%u\n", pcie_get_width(pci_dev));
> }
> static DEVICE_ATTR_RO(current_link_width);
>
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index d0131b5623b1..0858fa2f1c2d 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -6235,6 +6235,26 @@ enum pci_bus_speed pcie_get_speed(struct pci_dev *dev)
> }
> EXPORT_SYMBOL(pcie_get_speed);
>
> +/**
> + * pcie_get_width - query for the PCI device's current link width
> + * @dev: PCI device to query
> + *
> + * Query the PCI device current negoiated width.
> + */
> +
> +enum pcie_link_width pcie_get_width(struct pci_dev *dev)
> +{
> + u16 linkstat;
> + int err;
> +
> + err = pcie_capability_read_word(dev, PCI_EXP_LNKSTA, &linkstat);
> + if (err)
> + return PCIE_LNK_WIDTH_UNKNOWN;
> +
> + return FIELD_GET(PCI_EXP_LNKSTA_NLW, linkstat);
> +}
> +EXPORT_SYMBOL(pcie_get_width);
> +
> /**
> * pcie_bandwidth_capable - calculate a PCI device's link bandwidth capability
> * @dev: PCI device
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 6a065986ff8f..21eca09a98e2 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -305,6 +305,7 @@ enum pci_bus_speed {
>
> enum pci_bus_speed pcie_get_speed(struct pci_dev *dev);
> enum pci_bus_speed pcie_get_speed_cap(struct pci_dev *dev);
> +enum pcie_link_width pcie_get_width(struct pci_dev *dev);
> enum pcie_link_width pcie_get_width_cap(struct pci_dev *dev);
>
> struct pci_vpd {
>
>
