From: Alex Williamson <alex.williamson@redhat.com>
To: linux-pci@vger.kernel.org
Cc: bhelgaas@google.com, iommu@lists.linux-foundation.org,
linux-kernel@vger.kernel.org
Subject: [PATCH 2/5] PCI: Extract link speed & width retrieval from pcie_get_minimum_link()
Date: Wed, 26 Oct 2016 12:01:22 -0600 [thread overview]
Message-ID: <20161026180122.23495.26258.stgit@gimli.home> (raw)
In-Reply-To: <20161026175156.23495.12980.stgit@gimli.home>
Signed-off-by: Alex Williamson <alex.williamson@redhat.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);
next prev parent reply other threads:[~2016-10-26 18:01 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-26 18:01 [PATCH 0/5] PCI: ACS enable quirk for link balancing switches Alex Williamson
2016-10-26 18:01 ` [PATCH 1/5] PCI: Make pci_std_enable_acs() non-static Alex Williamson
2016-11-14 20:59 ` Bjorn Helgaas
2016-10-26 18:01 ` Alex Williamson [this message]
2016-11-14 21:02 ` [PATCH 2/5] PCI: Extract link speed & width retrieval from pcie_get_minimum_link() Bjorn Helgaas
2016-10-26 18:01 ` [PATCH 3/5] PCI: Extract link retraining from pcie_aspm_configure_common_clock() Alex Williamson
2016-10-26 20:42 ` Alex Williamson
2016-10-26 18:01 ` [PATCH 4/5] iommu: Move REQ_ACS_FLAGS out to header and rename Alex Williamson
2016-11-10 12:27 ` Joerg Roedel
2016-11-11 22:57 ` Bjorn Helgaas
2016-11-14 12:48 ` Joerg Roedel
2016-10-26 18:01 ` [PATCH 5/5] PCI: Balance ports to avoid ACS errata on Pericom switches Alex Williamson
2016-11-14 21:03 ` Bjorn Helgaas
2016-11-14 21:21 ` Alex Williamson
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