#include <linux/kernel.h>
#include <linux/delay.h>
+#include <linux/dmi.h>
#include <linux/init.h>
#include <linux/of.h>
#include <linux/of_pci.h>
/* If set, the PCIe ARI capability will not be used. */
static bool pcie_ari_disabled;
+/* Disable bridge_d3 for all PCIe ports */
+static bool pci_bridge_d3_disable;
+/* Force bridge_d3 for all PCIe ports */
+static bool pci_bridge_d3_force;
+
+static int __init pcie_port_pm_setup(char *str)
+{
+ if (!strcmp(str, "off"))
+ pci_bridge_d3_disable = true;
+ else if (!strcmp(str, "force"))
+ pci_bridge_d3_force = true;
+ return 1;
+}
+__setup("pcie_port_pm=", pcie_port_pm_setup);
+
/**
* pci_bus_max_busnr - returns maximum PCI bus number of given bus' children
* @bus: pointer to PCI bus structure to search
pm_runtime_put_sync(parent);
}
+/**
+ * pci_bridge_d3_possible - Is it possible to put the bridge into D3
+ * @bridge: Bridge to check
+ *
+ * This function checks if it is possible to move the bridge to D3.
+ * Currently we only allow D3 for recent enough PCIe ports.
+ */
+static bool pci_bridge_d3_possible(struct pci_dev *bridge)
+{
+ unsigned int year;
+
+ if (!pci_is_pcie(bridge))
+ return false;
+
+ switch (pci_pcie_type(bridge)) {
+ case PCI_EXP_TYPE_ROOT_PORT:
+ case PCI_EXP_TYPE_UPSTREAM:
+ case PCI_EXP_TYPE_DOWNSTREAM:
+ if (pci_bridge_d3_disable)
+ return false;
+ if (pci_bridge_d3_force)
+ return true;
+
+ /*
+ * It should be safe to put PCIe ports from 2015 or newer
+ * to D3.
+ */
+ if (dmi_get_date(DMI_BIOS_DATE, &year, NULL, NULL) &&
+ year >= 2015) {
+ return true;
+ }
+ break;
+ }
+
+ return false;
+}
+
+static int pci_dev_check_d3cold(struct pci_dev *dev, void *data)
+{
+ bool *d3cold_ok = data;
+ bool no_d3cold;
+
+ /*
+ * The device needs to be allowed to go D3cold and if it is wake
+ * capable to do so from D3cold.
+ */
+ no_d3cold = dev->no_d3cold || !dev->d3cold_allowed ||
+ (device_may_wakeup(&dev->dev) && !pci_pme_capable(dev, PCI_D3cold)) ||
+ !pci_power_manageable(dev);
+
+ *d3cold_ok = !no_d3cold;
+
+ return no_d3cold;
+}
+
+/*
+ * pci_bridge_d3_update - Update bridge D3 capabilities
+ * @dev: PCI device which is changed
+ * @remove: Is the device being removed
+ *
+ * Update upstream bridge PM capabilities accordingly depending on if the
+ * device PM configuration was changed or the device is being removed. The
+ * change is also propagated upstream.
+ */
+static void pci_bridge_d3_update(struct pci_dev *dev, bool remove)
+{
+ struct pci_dev *bridge;
+ bool d3cold_ok = true;
+
+ bridge = pci_upstream_bridge(dev);
+ if (!bridge || !pci_bridge_d3_possible(bridge))
+ return;
+
+ pci_dev_get(bridge);
+ /*
+ * If the device is removed we do not care about its D3cold
+ * capabilities.
+ */
+ if (!remove)
+ pci_dev_check_d3cold(dev, &d3cold_ok);
+
+ if (d3cold_ok) {
+ /*
+ * We need to go through all children to find out if all of
+ * them can still go to D3cold.
+ */
+ pci_walk_bus(bridge->subordinate, pci_dev_check_d3cold,
+ &d3cold_ok);
+ }
+
+ if (bridge->bridge_d3 != d3cold_ok) {
+ bridge->bridge_d3 = d3cold_ok;
+ /* Propagate change to upstream bridges */
+ pci_bridge_d3_update(bridge, false);
+ }
+
+ pci_dev_put(bridge);
+}
+
+/**
+ * pci_bridge_d3_device_changed - Update bridge D3 capabilities on change
+ * @dev: PCI device that was changed
+ *
+ * If a device is added or its PM configuration, such as is it allowed to
+ * enter D3cold, is changed this function updates upstream bridge PM
+ * capabilities accordingly.
+ */
+void pci_bridge_d3_device_changed(struct pci_dev *dev)
+{
+ pci_bridge_d3_update(dev, false);
+}
+
+/**
+ * pci_bridge_d3_device_removed - Update bridge D3 capabilities on remove
+ * @dev: PCI device being removed
+ *
+ * Function updates upstream bridge PM capabilities based on other devices
+ * still left on the bus.
+ */
+void pci_bridge_d3_device_removed(struct pci_dev *dev)
+{
+ pci_bridge_d3_update(dev, true);
+}
+
+/**
+ * pci_d3cold_enable - Enable D3cold for device
+ * @dev: PCI device to handle
+ *
+ * This function can be used in drivers to enable D3cold from the device
+ * they handle. It also updates upstream PCI bridge PM capabilities
+ * accordingly.
+ */
+void pci_d3cold_enable(struct pci_dev *dev)
+{
+ if (dev->no_d3cold) {
+ dev->no_d3cold = false;
+ pci_bridge_d3_device_changed(dev);
+ }
+}
+EXPORT_SYMBOL_GPL(pci_d3cold_enable);
+
+/**
+ * pci_d3cold_disable - Disable D3cold for device
+ * @dev: PCI device to handle
+ *
+ * This function can be used in drivers to disable D3cold from the device
+ * they handle. It also updates upstream PCI bridge PM capabilities
+ * accordingly.
+ */
+void pci_d3cold_disable(struct pci_dev *dev)
+{
+ if (!dev->no_d3cold) {
+ dev->no_d3cold = true;
+ pci_bridge_d3_device_changed(dev);
+ }
+}
+EXPORT_SYMBOL_GPL(pci_d3cold_disable);
+
/**
* pci_pm_init - Initialize PM functions of given PCI device
* @dev: PCI device to handle.
dev->pm_cap = pm;
dev->d3_delay = PCI_PM_D3_WAIT;
dev->d3cold_delay = PCI_PM_D3COLD_WAIT;
+ dev->bridge_d3 = pci_bridge_d3_possible(dev);
dev->d3cold_allowed = true;
dev->d1_support = false;
projects / deliverable / linux.git / commitdiff
