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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2019-08-09 10:23:57 +0200
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2019-08-12 10:47:55 +0200
commitaccd2dd72c8f087441d725dd916688171519e4e6 (patch)
treeaf9a6de3e2673da837977223ea89a56e39d90055 /drivers/pci
parentd45331b00ddb179e291766617259261c112db872 (diff)
PCI/ASPM: Add pcie_aspm_enabled()
Add a function checking whether or not PCIe ASPM has been enabled for a given device. It will be used by the NVMe driver to decide how to handle the device during system suspend. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Keith Busch <keith.busch@intel.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'drivers/pci')
-rw-r--r--drivers/pci/pcie/aspm.c20
1 files changed, 20 insertions, 0 deletions
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index e44af7f4d37f..464f8f92653f 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -1170,6 +1170,26 @@ static int pcie_aspm_get_policy(char *buffer, const struct kernel_param *kp)
module_param_call(policy, pcie_aspm_set_policy, pcie_aspm_get_policy,
NULL, 0644);
+/**
+ * pcie_aspm_enabled - Check if PCIe ASPM has been enabled for a device.
+ * @pdev: Target device.
+ */
+bool pcie_aspm_enabled(struct pci_dev *pdev)
+{
+ struct pci_dev *bridge = pci_upstream_bridge(pdev);
+ bool ret;
+
+ if (!bridge)
+ return false;
+
+ mutex_lock(&aspm_lock);
+ ret = bridge->link_state ? !!bridge->link_state->aspm_enabled : false;
+ mutex_unlock(&aspm_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(pcie_aspm_enabled);
+
#ifdef CONFIG_PCIEASPM_DEBUG
static ssize_t link_state_show(struct device *dev,
struct device_attribute *attr,