+/**
+ * pci_pme_capable - check the capability of PCI device to generate PME#
+ * @dev: PCI device to handle.
+ * @pm: PCI PM capability offset of the device.
+ * @state: PCI state from which device will issue PME#.
+ */
+static bool pci_pme_capable(struct pci_dev *dev, int pm, pci_power_t state)
+{
+ u16 pmc;
+
+ if (!pm)
+ return false;
+
+ /* Check device's ability to generate PME# from given state */
+ pci_read_config_word(dev, pm + PCI_PM_PMC, &pmc);
+
+ pmc &= PCI_PM_CAP_PME_MASK;
+ pmc >>= ffs(PCI_PM_CAP_PME_MASK) - 1; /* First bit of mask */
+
+ return !!(pmc & (1 << state));
+}
+
+/**
+ * pci_pme_active - enable or disable PCI device's PME# function
+ * @dev: PCI device to handle.
+ * @pm: PCI PM capability offset of the device.
+ * @enable: 'true' to enable PME# generation; 'false' to disable it.
+ *
+ * The caller must verify that the device is capable of generating PME# before
+ * calling this function with @enable equal to 'true'.
+ */
+static void pci_pme_active(struct pci_dev *dev, int pm, bool enable)
+{
+ u16 pmcsr;
+
+ if (!pm)
+ return;
+
+ pci_read_config_word(dev, pm + PCI_PM_CTRL, &pmcsr);
+ /* Clear PME_Status by writing 1 to it and enable PME# */
+ pmcsr |= PCI_PM_CTRL_PME_STATUS | PCI_PM_CTRL_PME_ENABLE;
+ if (!enable)
+ pmcsr &= ~PCI_PM_CTRL_PME_ENABLE;
+
+ pci_write_config_word(dev, pm + PCI_PM_CTRL, pmcsr);
+
+ dev_printk(KERN_INFO, &dev->dev, "PME# %s\n",
+ enable ? "enabled" : "disabled");
+}
+