[PATCH 2/5] PCI: Extract link speed & width retrieval from pcie_get_minimum_link()

From: Alex Williamson
Date: Wed Oct 26 2016 - 14:01:30 EST


Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
---
drivers/pci/pci.c | 26 ++++++++++++++++++++------
include/linux/pci.h | 2 ++
2 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index b901ee7..6d6cf89 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4729,6 +4729,25 @@ int pcie_set_mps(struct pci_dev *dev, int mps)
}
EXPORT_SYMBOL(pcie_set_mps);

+int pcie_get_link(struct pci_dev *dev, enum pci_bus_speed *speed,
+ enum pcie_link_width *width)
+{
+ int ret;
+ u16 lnksta;
+
+ ret = pcie_capability_read_word(dev, PCI_EXP_LNKSTA, &lnksta);
+ if (ret)
+ return ret;
+
+ if (speed)
+ *speed = pcie_link_speed[lnksta & PCI_EXP_LNKSTA_CLS];
+ if (width)
+ *width = (lnksta & PCI_EXP_LNKSTA_NLW) >>
+ PCI_EXP_LNKSTA_NLW_SHIFT;
+
+ return 0;
+}
+
/**
* pcie_get_minimum_link - determine minimum link settings of a PCI device
* @dev: PCI device to query
@@ -4747,18 +4766,13 @@ int pcie_get_minimum_link(struct pci_dev *dev, enum pci_bus_speed *speed,
*width = PCIE_LNK_WIDTH_UNKNOWN;

while (dev) {
- u16 lnksta;
enum pci_bus_speed next_speed;
enum pcie_link_width next_width;

- ret = pcie_capability_read_word(dev, PCI_EXP_LNKSTA, &lnksta);
+ ret = pcie_get_link(dev, &next_speed, &next_width);
if (ret)
return ret;

- next_speed = pcie_link_speed[lnksta & PCI_EXP_LNKSTA_CLS];
- next_width = (lnksta & PCI_EXP_LNKSTA_NLW) >>
- PCI_EXP_LNKSTA_NLW_SHIFT;
-
if (next_speed < *speed)
*speed = next_speed;

diff --git a/include/linux/pci.h b/include/linux/pci.h
index c3248d5..fbfbb40 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1026,6 +1026,8 @@ 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_link(struct pci_dev *dev, enum pci_bus_speed *speed,
+ enum pcie_link_width *width);
int __pci_reset_function(struct pci_dev *dev);
int __pci_reset_function_locked(struct pci_dev *dev);
int pci_reset_function(struct pci_dev *dev);