linux-kernel - [PATCH 2/5] PCI: Extract link speed & width retrieval from pcie_get_minimum

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Date:   Wed, 26 Oct 2016 12:01:22 -0600
From:   Alex Williamson <alex.williamson@...hat.com>
To:     linux-pci@...r.kernel.org
Cc:     bhelgaas@...gle.com, iommu@...ts.linux-foundation.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH 2/5] PCI: Extract link speed & width retrieval from
 pcie_get_minimum_link()

Signed-off-by: Alex Williamson <alex.williamson@...hat.com>
---
 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);