Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit c70b65fb authored by Tal Gilboa's avatar Tal Gilboa Committed by Bjorn Helgaas
Browse files

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: default avatarTal Gilboa <talgi@mellanox.com>
[bhelgaas: return width directly instead of error and *width, don't export
outside drivers/pci]
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: default avatarTariq Toukan <tariqt@mellanox.com>
parent 6cf57be0

drivers/pci/pci-sysfs.c

+2 −8
Original line number Diff line number Diff line
@@ -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);

drivers/pci/pci.c

+18 −0
Original line number Diff line number Diff line
@@ -5190,6 +5190,24 @@ enum pci_bus_speed pcie_get_speed_cap(struct pci_dev *dev) 
	return PCI_SPEED_UNKNOWN;

}



/**

 * 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

drivers/pci/pci.h

+1 −0
Original line number Diff line number Diff line
@@ -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 {