Merge back PCI power management material for v5.3.

5 files changed, 194 insertions, 41 deletions

diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index 1897847ceb0c..45049f558860 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -685,12 +685,21 @@ static pci_power_t acpi_pci_get_power_state(struct pci_dev *dev)
 	if (!adev || !acpi_device_power_manageable(adev))
 		return PCI_UNKNOWN;
 
-	if (acpi_device_get_power(adev, &state) || state == ACPI_STATE_UNKNOWN)
+	state = adev->power.state;
+	if (state == ACPI_STATE_UNKNOWN)
 		return PCI_UNKNOWN;
 
 	return state_conv[state];
 }
 
+static void acpi_pci_refresh_power_state(struct pci_dev *dev)
+{
+	struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
+
+	if (adev && acpi_device_power_manageable(adev))
+		acpi_device_update_power(adev, NULL);
+}
+
 static int acpi_pci_propagate_wakeup(struct pci_bus *bus, bool enable)
 {
 	while (bus->parent) {
@@ -748,6 +757,7 @@ static const struct pci_platform_pm_ops acpi_pci_platform_pm = {
 	.is_manageable = acpi_pci_power_manageable,
 	.set_state = acpi_pci_set_power_state,
 	.get_state = acpi_pci_get_power_state,
+	.refresh_state = acpi_pci_refresh_power_state,
 	.choose_state = acpi_pci_choose_state,
 	.set_wakeup = acpi_pci_wakeup,
 	.need_resume = acpi_pci_need_resume,
@@ -901,6 +911,7 @@ static void pci_acpi_setup(struct device *dev)
 		device_wakeup_enable(dev);
 
 	acpi_pci_wakeup(pci_dev, false);
+	acpi_device_power_add_dependent(adev, dev);
 }
 
 static void pci_acpi_cleanup(struct device *dev)
@@ -913,6 +924,7 @@ static void pci_acpi_cleanup(struct device *dev)
 
 	pci_acpi_remove_pm_notifier(adev);
 	if (adev->wakeup.flags.valid) {
+		acpi_device_power_remove_dependent(adev, dev);
 		if (pci_dev->bridge_d3)
 			device_wakeup_disable(dev);
 
diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index ca3793002e2f..a00820d8aa74 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -678,6 +678,7 @@ static bool pci_has_legacy_pm_support(struct pci_dev *pci_dev)
 static int pci_pm_prepare(struct device *dev)
 {
 	struct device_driver *drv = dev->driver;
+	struct pci_dev *pci_dev = to_pci_dev(dev);
 
 	if (drv && drv->pm && drv->pm->prepare) {
 		int error = drv->pm->prepare(dev);
@@ -687,7 +688,15 @@ static int pci_pm_prepare(struct device *dev)
 		if (!error && dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_PREPARE))
 			return 0;
 	}
-	return pci_dev_keep_suspended(to_pci_dev(dev));
+	if (pci_dev_need_resume(pci_dev))
+		return 0;
+
+	/*
+	 * The PME setting needs to be adjusted here in case the direct-complete
+	 * optimization is used with respect to this device.
+	 */
+	pci_dev_adjust_pme(pci_dev);
+	return 1;
 }
 
 static void pci_pm_complete(struct device *dev)
@@ -701,7 +710,14 @@ static void pci_pm_complete(struct device *dev)
 	if (pm_runtime_suspended(dev) && pm_resume_via_firmware()) {
 		pci_power_t pre_sleep_state = pci_dev->current_state;
 
-		pci_update_current_state(pci_dev, pci_dev->current_state);
+		pci_refresh_power_state(pci_dev);
+		/*
+		 * On platforms with ACPI this check may also trigger for
+		 * devices sharing power resources if one of those power
+		 * resources has been activated as a result of a change of the
+		 * power state of another device sharing it.  However, in that
+		 * case it is also better to resume the device, in general.
+		 */
 		if (pci_dev->current_state < pre_sleep_state)
 			pm_request_resume(dev);
 	}
@@ -757,9 +773,11 @@ static int pci_pm_suspend(struct device *dev)
 	 * better to resume the device from runtime suspend here.
 	 */
 	if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) ||
-	    !pci_dev_keep_suspended(pci_dev)) {
+	    pci_dev_need_resume(pci_dev)) {
 		pm_runtime_resume(dev);
 		pci_dev->state_saved = false;
+	} else {
+		pci_dev_adjust_pme(pci_dev);
 	}
 
 	if (pm->suspend) {
@@ -1130,10 +1148,13 @@ static int pci_pm_poweroff(struct device *dev)
 
 	/* The reason to do that is the same as in pci_pm_suspend(). */
 	if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) ||
-	    !pci_dev_keep_suspended(pci_dev))
+	    pci_dev_need_resume(pci_dev)) {
 		pm_runtime_resume(dev);
+		pci_dev->state_saved = false;
+	} else {
+		pci_dev_adjust_pme(pci_dev);
+	}
 
-	pci_dev->state_saved = false;
 	if (pm->poweroff) {
 		int error;
 
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 8abc843b1615..b1f563916036 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -777,6 +777,12 @@ static inline pci_power_t platform_pci_get_power_state(struct pci_dev *dev)
 	return pci_platform_pm ? pci_platform_pm->get_state(dev) : PCI_UNKNOWN;
 }
 
+static inline void platform_pci_refresh_power_state(struct pci_dev *dev)
+{
+	if (pci_platform_pm && pci_platform_pm->refresh_state)
+		pci_platform_pm->refresh_state(dev);
+}
+
 static inline pci_power_t platform_pci_choose_state(struct pci_dev *dev)
 {
 	return pci_platform_pm ?
@@ -938,6 +944,21 @@ void pci_update_current_state(struct pci_dev *dev, pci_power_t state)
 }
 
 /**
+ * pci_refresh_power_state - Refresh the given device's power state data
+ * @dev: Target PCI device.
+ *
+ * Ask the platform to refresh the devices power state information and invoke
+ * pci_update_current_state() to update its current PCI power state.
+ */
+void pci_refresh_power_state(struct pci_dev *dev)
+{
+	if (platform_pci_power_manageable(dev))
+		platform_pci_refresh_power_state(dev);
+
+	pci_update_current_state(dev, dev->current_state);
+}
+
+/**
  * pci_power_up - Put the given device into D0 forcibly
  * @dev: PCI device to power up
  */
@@ -1004,15 +1025,10 @@ static void __pci_start_power_transition(struct pci_dev *dev, pci_power_t state)
 	if (state == PCI_D0) {
 		pci_platform_power_transition(dev, PCI_D0);
 		/*
-		 * Mandatory power management transition delays, see
-		 * PCI Express Base Specification Revision 2.0 Section
-		 * 6.6.1: Conventional Reset.  Do not delay for
-		 * devices powered on/off by corresponding bridge,
-		 * because have already delayed for the bridge.
+		 * Mandatory power management transition delays are
+		 * handled in the PCIe portdrv resume hooks.
 		 */
 		if (dev->runtime_d3cold) {
-			if (dev->d3cold_delay && !dev->imm_ready)
-				msleep(dev->d3cold_delay);
 			/*
 			 * When powering on a bridge from D3cold, the
 			 * whole hierarchy may be powered on into
@@ -2065,6 +2081,13 @@ static void pci_pme_list_scan(struct work_struct *work)
 			 */
 			if (bridge && bridge->current_state != PCI_D0)
 				continue;
+			/*
+			 * If the device is in D3cold it should not be
+			 * polled either.
+			 */
+			if (pme_dev->dev->current_state == PCI_D3cold)
+				continue;
+
 			pci_pme_wakeup(pme_dev->dev, NULL);
 		} else {
 			list_del(&pme_dev->list);
@@ -2459,45 +2482,56 @@ bool pci_dev_run_wake(struct pci_dev *dev)
 EXPORT_SYMBOL_GPL(pci_dev_run_wake);
 
 /**
- * pci_dev_keep_suspended - Check if the device can stay in the suspended state.
+ * pci_dev_need_resume - Check if it is necessary to resume the device.
  * @pci_dev: Device to check.
  *
- * Return 'true' if the device is runtime-suspended, it doesn't have to be
+ * Return 'true' if the device is not runtime-suspended or it has to be
  * reconfigured due to wakeup settings difference between system and runtime
- * suspend and the current power state of it is suitable for the upcoming
- * (system) transition.
- *
- * If the device is not configured for system wakeup, disable PME for it before
- * returning 'true' to prevent it from waking up the system unnecessarily.
+ * suspend, or the current power state of it is not suitable for the upcoming
+ * (system-wide) transition.
  */
-bool pci_dev_keep_suspended(struct pci_dev *pci_dev)
+bool pci_dev_need_resume(struct pci_dev *pci_dev)
 {
 	struct device *dev = &pci_dev->dev;
-	bool wakeup = device_may_wakeup(dev);
+	pci_power_t target_state;
 
-	if (!pm_runtime_suspended(dev)
-	    || pci_target_state(pci_dev, wakeup) != pci_dev->current_state
-	    || platform_pci_need_resume(pci_dev))
-		return false;
+	if (!pm_runtime_suspended(dev) || platform_pci_need_resume(pci_dev))
+		return true;
+
+	target_state = pci_target_state(pci_dev, device_may_wakeup(dev));
 
 	/*
-	 * At this point the device is good to go unless it's been configured
-	 * to generate PME at the runtime suspend time, but it is not supposed
-	 * to wake up the system.  In that case, simply disable PME for it
-	 * (it will have to be re-enabled on exit from system resume).
-	 *
-	 * If the device's power state is D3cold and the platform check above
-	 * hasn't triggered, the device's configuration is suitable and we don't
-	 * need to manipulate it at all.
+	 * If the earlier platform check has not triggered, D3cold is just power
+	 * removal on top of D3hot, so no need to resume the device in that
+	 * case.
 	 */
+	return target_state != pci_dev->current_state &&
+		target_state != PCI_D3cold &&
+		pci_dev->current_state != PCI_D3hot;
+}
+
+/**
+ * pci_dev_adjust_pme - Adjust PME setting for a suspended device.
+ * @pci_dev: Device to check.
+ *
+ * If the device is suspended and it is not configured for system wakeup,
+ * disable PME for it to prevent it from waking up the system unnecessarily.
+ *
+ * Note that if the device's power state is D3cold and the platform check in
+ * pci_dev_need_resume() has not triggered, the device's configuration need not
+ * be changed.
+ */
+void pci_dev_adjust_pme(struct pci_dev *pci_dev)
+{
+	struct device *dev = &pci_dev->dev;
+
 	spin_lock_irq(&dev->power.lock);
 
-	if (pm_runtime_suspended(dev) && pci_dev->current_state < PCI_D3cold &&
-	    !wakeup)
+	if (pm_runtime_suspended(dev) && !device_may_wakeup(dev) &&
+	    pci_dev->current_state < PCI_D3cold)
 		__pci_pme_active(pci_dev, false);
 
 	spin_unlock_irq(&dev->power.lock);
-	return true;
 }
 
 /**
@@ -4568,14 +4602,16 @@ static int pci_pm_reset(struct pci_dev *dev, int probe)
 
 	return pci_dev_wait(dev, "PM D3->D0", PCIE_RESET_READY_POLL_MS);
 }
+
 /**
- * pcie_wait_for_link - Wait until link is active or inactive
+ * pcie_wait_for_link_delay - Wait until link is active or inactive
  * @pdev: Bridge device
  * @active: waiting for active or inactive?
+ * @delay: Delay to wait after link has become active (in ms)
  *
  * Use this to wait till link becomes active or inactive.
  */
-bool pcie_wait_for_link(struct pci_dev *pdev, bool active)
+bool pcie_wait_for_link_delay(struct pci_dev *pdev, bool active, int delay)
 {
 	int timeout = 1000;
 	bool ret;
@@ -4612,13 +4648,25 @@ bool pcie_wait_for_link(struct pci_dev *pdev, bool active)
 		timeout -= 10;
 	}
 	if (active && ret)
-		msleep(100);
+		msleep(delay);
 	else if (ret != active)
 		pci_info(pdev, "Data Link Layer Link Active not %s in 1000 msec\n",
 			active ? "set" : "cleared");
 	return ret == active;
 }
 
+/**
+ * pcie_wait_for_link - Wait until link is active or inactive
+ * @pdev: Bridge device
+ * @active: waiting for active or inactive?
+ *
+ * Use this to wait till link becomes active or inactive.
+ */
+bool pcie_wait_for_link(struct pci_dev *pdev, bool active)
+{
+	return pcie_wait_for_link_delay(pdev, active, 100);
+}
+
 void pci_reset_secondary_bus(struct pci_dev *dev)
 {
 	u16 ctrl;
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 9cb99380c61e..5db6f985f16d 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -51,6 +51,8 @@ int pci_bus_error_reset(struct pci_dev *dev);
  *
  * @get_state: queries the platform firmware for a device's current power state
  *
+ * @refresh_state: asks the platform to refresh the device's power state data
+ *
  * @choose_state: returns PCI power state of given device preferred by the
  *		  platform; to be used during system-wide transitions from a
  *		  sleeping state to the working state and vice versa
@@ -69,6 +71,7 @@ struct pci_platform_pm_ops {
 	bool (*is_manageable)(struct pci_dev *dev);
 	int (*set_state)(struct pci_dev *dev, pci_power_t state);
 	pci_power_t (*get_state)(struct pci_dev *dev);
+	void (*refresh_state)(struct pci_dev *dev);
 	pci_power_t (*choose_state)(struct pci_dev *dev);
 	int (*set_wakeup)(struct pci_dev *dev, bool enable);
 	bool (*need_resume)(struct pci_dev *dev);
@@ -76,13 +79,15 @@ struct pci_platform_pm_ops {
 
 int pci_set_platform_pm(const struct pci_platform_pm_ops *ops);
 void pci_update_current_state(struct pci_dev *dev, pci_power_t state);
+void pci_refresh_power_state(struct pci_dev *dev);
 void pci_power_up(struct pci_dev *dev);
 void pci_disable_enabled_device(struct pci_dev *dev);
 int pci_finish_runtime_suspend(struct pci_dev *dev);
 void pcie_clear_root_pme_status(struct pci_dev *dev);
 int __pci_pme_wakeup(struct pci_dev *dev, void *ign);
 void pci_pme_restore(struct pci_dev *dev);
-bool pci_dev_keep_suspended(struct pci_dev *dev);
+bool pci_dev_need_resume(struct pci_dev *dev);
+void pci_dev_adjust_pme(struct pci_dev *dev);
 void pci_dev_complete_resume(struct pci_dev *pci_dev);
 void pci_config_pm_runtime_get(struct pci_dev *dev);
 void pci_config_pm_runtime_put(struct pci_dev *dev);
@@ -493,6 +498,7 @@ static inline int pci_dev_specific_disable_acs_redir(struct pci_dev *dev)
 void pcie_do_recovery(struct pci_dev *dev, enum pci_channel_state state,
 		      u32 service);
 
+bool pcie_wait_for_link_delay(struct pci_dev *pdev, bool active, int delay);
 bool pcie_wait_for_link(struct pci_dev *pdev, bool active);
 #ifdef CONFIG_PCIEASPM
 void pcie_aspm_init_link_state(struct pci_dev *pdev);
diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c
index 1b330129089f..308c3e0c4a34 100644
--- a/drivers/pci/pcie/portdrv_core.c
+++ b/drivers/pci/pcie/portdrv_core.c
@@ -9,6 +9,7 @@
 #include <linux/module.h>
 #include <linux/pci.h>
 #include <linux/kernel.h>
+#include <linux/delay.h>
 #include <linux/errno.h>
 #include <linux/pm.h>
 #include <linux/pm_runtime.h>
@@ -378,6 +379,67 @@ static int pm_iter(struct device *dev, void *data)
 	return 0;
 }
 
+static int get_downstream_delay(struct pci_bus *bus)
+{
+	struct pci_dev *pdev;
+	int min_delay = 100;
+	int max_delay = 0;
+
+	list_for_each_entry(pdev, &bus->devices, bus_list) {
+		if (!pdev->imm_ready)
+			min_delay = 0;
+		else if (pdev->d3cold_delay < min_delay)
+			min_delay = pdev->d3cold_delay;
+		if (pdev->d3cold_delay > max_delay)
+			max_delay = pdev->d3cold_delay;
+	}
+
+	return max(min_delay, max_delay);
+}
+
+/*
+ * wait_for_downstream_link - Wait for downstream link to establish
+ * @pdev: PCIe port whose downstream link is waited
+ *
+ * Handle delays according to PCIe 4.0 section 6.6.1 before configuration
+ * access to the downstream component is permitted.
+ *
+ * This blocks PCI core resume of the hierarchy below this port until the
+ * link is trained. Should be called before resuming port services to
+ * prevent pciehp from starting to tear-down the hierarchy too soon.
+ */
+static void wait_for_downstream_link(struct pci_dev *pdev)
+{
+	int delay;
+
+	if (pci_pcie_type(pdev) != PCI_EXP_TYPE_ROOT_PORT &&
+	    pci_pcie_type(pdev) != PCI_EXP_TYPE_DOWNSTREAM)
+		return;
+
+	if (pci_dev_is_disconnected(pdev))
+		return;
+
+	if (!pdev->subordinate || list_empty(&pdev->subordinate->devices) ||
+	    !pdev->bridge_d3)
+		return;
+
+	delay = get_downstream_delay(pdev->subordinate);
+	if (!delay)
+		return;
+
+	dev_dbg(&pdev->dev, "waiting downstream link for %d ms\n", delay);
+
+	/*
+	 * If downstream port does not support speeds greater than 5 GT/s
+	 * need to wait 100ms. For higher speeds (gen3) we need to wait
+	 * first for the data link layer to become active.
+	 */
+	if (pcie_get_speed_cap(pdev) <= PCIE_SPEED_5_0GT)
+		msleep(delay);
+	else
+		pcie_wait_for_link_delay(pdev, true, delay);
+}
+
 /**
  * pcie_port_device_suspend - suspend port services associated with a PCIe port
  * @dev: PCI Express port to handle
@@ -391,6 +453,8 @@ int pcie_port_device_suspend(struct device *dev)
 int pcie_port_device_resume_noirq(struct device *dev)
 {
 	size_t off = offsetof(struct pcie_port_service_driver, resume_noirq);
+
+	wait_for_downstream_link(to_pci_dev(dev));
 	return device_for_each_child(dev, &off, pm_iter);
 }
 
@@ -421,6 +485,8 @@ int pcie_port_device_runtime_suspend(struct device *dev)
 int pcie_port_device_runtime_resume(struct device *dev)
 {
 	size_t off = offsetof(struct pcie_port_service_driver, runtime_resume);
+
+	wait_for_downstream_link(to_pci_dev(dev));
 	return device_for_each_child(dev, &off, pm_iter);
 }
 #endif /* PM */