ACPI and power management fixes and new device IDs for 3.13-rc7

- VGA switcheroo was broken for some users as a result of the ACPI-based
   PCI hotplug (ACPIPHP) changes in 3.12, because some previously ignored
   hotplug events started to be handled.  The fix causes them to be
   ignored again.
 
 - There are two more issues related to cpufreq's suspend/resume handling
   changes from the 3.12 cycle addressed by Viresh Kumar's fixes.
 
 - intel_pstate triggers a divide error in a timer function if the P-state
   information it needs is missing during initialization.  This leads to
   kernel panics on nested KVM clients and is fixed by failing the
   initialization cleanly in those cases.
 
 - PCI initalization code changes during the 3.9 cycle uncovered BIOS
   issues related to ACPI wakeup notifications (some BIOSes send them
   for devices that aren't supposed to support ACPI wakeup).  Work around
   them by installing an ACPI wakeup notify handler for all PCI devices
   with ACPI support.
 
 - The Calxeda cpuilde driver's probe function is tagged as __init, which
   is incorrect and causes a section mismatch to occur during build.  Fix
   from Andre Przywara removes the __init tag from there.
 
 - During the 3.12 cycle ACPIPHP started to print warnings about missing
   _ADR for devices that legitimately don't have it.  Fix from Toshi Kani
   makes it only print the warnings where they make sense.
 
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Merge tag 'pm+acpi-3.13-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull ACPI and PM fixes and new device IDs from Rafael Wysocki:
 "These commits, except for one, are regression fixes and the remaining
  one fixes a divide error leading to a kernel panic.  The majority of
  the regressions fixed here were introduced during the 3.12 cycle, one
  of them is from this cycle and one is older.

  Specifics:

   - VGA switcheroo was broken for some users as a result of the
     ACPI-based PCI hotplug (ACPIPHP) changes in 3.12, because some
     previously ignored hotplug events started to be handled.  The fix
     causes them to be ignored again.

   - There are two more issues related to cpufreq's suspend/resume
     handling changes from the 3.12 cycle addressed by Viresh Kumar's
     fixes.

   - intel_pstate triggers a divide error in a timer function if the
     P-state information it needs is missing during initialization.
     This leads to kernel panics on nested KVM clients and is fixed by
     failing the initialization cleanly in those cases.

   - PCI initalization code changes during the 3.9 cycle uncovered BIOS
     issues related to ACPI wakeup notifications (some BIOSes send them
     for devices that aren't supposed to support ACPI wakeup).  Work
     around them by installing an ACPI wakeup notify handler for all PCI
     devices with ACPI support.

   - The Calxeda cpuilde driver's probe function is tagged as __init,
     which is incorrect and causes a section mismatch to occur during
     build.  Fix from Andre Przywara removes the __init tag from there.

   - During the 3.12 cycle ACPIPHP started to print warnings about
     missing _ADR for devices that legitimately don't have it.  Fix from
     Toshi Kani makes it only print the warnings where they make sense"

* tag 'pm+acpi-3.13-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPIPHP / radeon / nouveau: Fix VGA switcheroo problem related to hotplug
  intel_pstate: Fail initialization if P-state information is missing
  ARM/cpuidle: remove __init tag from Calxeda cpuidle probe function
  PCI / ACPI: Install wakeup notify handlers for all PCI devs with ACPI
  cpufreq: preserve user_policy across suspend/resume
  cpufreq: Clean up after a failing light-weight initialization
  ACPI / PCI / hotplug: Avoid warning when _ADR not present

drivers/acpi/bus.c

@@ -156,6 +156,16 @@ int acpi_bus_get_private_data(acpi_handle handle, void **data)
 }
 EXPORT_SYMBOL(acpi_bus_get_private_data);
 
+void acpi_bus_no_hotplug(acpi_handle handle)
+{
+	struct acpi_device *adev = NULL;
+
+	acpi_bus_get_device(handle, &adev);
+	if (adev)
+		adev->flags.no_hotplug = true;
+}
+EXPORT_SYMBOL_GPL(acpi_bus_no_hotplug);
+
 static void acpi_print_osc_error(acpi_handle handle,
 	struct acpi_osc_context *context, char *error)
 {

drivers/cpufreq/cpufreq.c

@@ -839,9 +839,6 @@ static void cpufreq_init_policy(struct cpufreq_policy *policy)
 
 	/* set default policy */
 	ret = cpufreq_set_policy(policy, &new_policy);
-	policy->user_policy.policy = policy->policy;
-	policy->user_policy.governor = policy->governor;
-
 	if (ret) {
 		pr_debug("setting policy failed\n");
 		if (cpufreq_driver->exit)
@@ -1016,15 +1013,17 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif,
 	read_unlock_irqrestore(&cpufreq_driver_lock, flags);
 #endif
 
-	if (frozen)
-		/* Restore the saved policy when doing light-weight init */
-		policy = cpufreq_policy_restore(cpu);
-	else
+	/*
+	 * Restore the saved policy when doing light-weight init and fall back
+	 * to the full init if that fails.
+	 */
+	policy = frozen ? cpufreq_policy_restore(cpu) : NULL;
+	if (!policy) {
+		frozen = false;
 		policy = cpufreq_policy_alloc();
-
-	if (!policy)
-		goto nomem_out;
-
+		if (!policy)
+			goto nomem_out;
+	}
 
 	/*
 	 * In the resume path, since we restore a saved policy, the assignment
@@ -1069,8 +1068,10 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif,
 	 */
 	cpumask_and(policy->cpus, policy->cpus, cpu_online_mask);
 
-	policy->user_policy.min = policy->min;
-	policy->user_policy.max = policy->max;
+	if (!frozen) {
+		policy->user_policy.min = policy->min;
+		policy->user_policy.max = policy->max;
+	}
 
 	blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
 				     CPUFREQ_START, policy);
@@ -1101,6 +1102,11 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif,
 
 	cpufreq_init_policy(policy);
 
+	if (!frozen) {
+		policy->user_policy.policy = policy->policy;
+		policy->user_policy.governor = policy->governor;
+	}
+
 	kobject_uevent(&policy->kobj, KOBJ_ADD);
 	up_read(&cpufreq_rwsem);
 
@@ -1118,8 +1124,11 @@ err_get_freq:
 	if (cpufreq_driver->exit)
 		cpufreq_driver->exit(policy);
 err_set_policy_cpu:
-	if (frozen)
+	if (frozen) {
+		/* Do not leave stale fallback data behind. */
+		per_cpu(cpufreq_cpu_data_fallback, cpu) = NULL;
 		cpufreq_policy_put_kobj(policy);
+	}
 	cpufreq_policy_free(policy);
 
 nomem_out:

drivers/cpufreq/intel_pstate.c

@@ -614,6 +614,11 @@ static int intel_pstate_init_cpu(unsigned int cpunum)
 	cpu = all_cpu_data[cpunum];
 
 	intel_pstate_get_cpu_pstates(cpu);
+	if (!cpu->pstate.current_pstate) {
+		all_cpu_data[cpunum] = NULL;
+		kfree(cpu);
+		return -ENODATA;
+	}
 
 	cpu->cpu = cpunum;
 

drivers/cpuidle/cpuidle-calxeda.c

@@ -65,7 +65,7 @@ static struct cpuidle_driver calxeda_idle_driver = {
 	.state_count = 2,
 };
 
-static int __init calxeda_cpuidle_probe(struct platform_device *pdev)
+static int calxeda_cpuidle_probe(struct platform_device *pdev)
 {
 	return cpuidle_register(&calxeda_idle_driver, NULL);
 }

drivers/gpu/drm/nouveau/nouveau_acpi.c

@@ -51,6 +51,7 @@ static struct nouveau_dsm_priv {
 	bool dsm_detected;
 	bool optimus_detected;
 	acpi_handle dhandle;
+	acpi_handle other_handle;
 	acpi_handle rom_handle;
 } nouveau_dsm_priv;
 
@@ -260,9 +261,10 @@ static int nouveau_dsm_pci_probe(struct pci_dev *pdev)
 	if (!dhandle)
 		return false;
 
-	if (!acpi_has_method(dhandle, "_DSM"))
+	if (!acpi_has_method(dhandle, "_DSM")) {
+		nouveau_dsm_priv.other_handle = dhandle;
 		return false;
-
+	}
 	if (nouveau_test_dsm(dhandle, nouveau_dsm, NOUVEAU_DSM_POWER))
 		retval |= NOUVEAU_DSM_HAS_MUX;
 
@@ -338,6 +340,16 @@ static bool nouveau_dsm_detect(void)
 		printk(KERN_INFO "VGA switcheroo: detected DSM switching method %s handle\n",
 			acpi_method_name);
 		nouveau_dsm_priv.dsm_detected = true;
+		/*
+		 * On some systems hotplug events are generated for the device
+		 * being switched off when _DSM is executed.  They cause ACPI
+		 * hotplug to trigger and attempt to remove the device from
+		 * the system, which causes it to break down.  Prevent that from
+		 * happening by setting the no_hotplug flag for the involved
+		 * ACPI device objects.
+		 */
+		acpi_bus_no_hotplug(nouveau_dsm_priv.dhandle);
+		acpi_bus_no_hotplug(nouveau_dsm_priv.other_handle);
 		ret = true;
 	}
 

drivers/gpu/drm/radeon/radeon_atpx_handler.c

@@ -33,6 +33,7 @@ static struct radeon_atpx_priv {
 	bool atpx_detected;
 	/* handle for device - and atpx */
 	acpi_handle dhandle;
+	acpi_handle other_handle;
 	struct radeon_atpx atpx;
 } radeon_atpx_priv;
 
@@ -451,9 +452,10 @@ static bool radeon_atpx_pci_probe_handle(struct pci_dev *pdev)
 		return false;
 
 	status = acpi_get_handle(dhandle, "ATPX", &atpx_handle);
-	if (ACPI_FAILURE(status))
+	if (ACPI_FAILURE(status)) {
+		radeon_atpx_priv.other_handle = dhandle;
 		return false;
-
+	}
 	radeon_atpx_priv.dhandle = dhandle;
 	radeon_atpx_priv.atpx.handle = atpx_handle;
 	return true;
@@ -530,6 +532,16 @@ static bool radeon_atpx_detect(void)
 		printk(KERN_INFO "VGA switcheroo: detected switching method %s handle\n",
 		       acpi_method_name);
 		radeon_atpx_priv.atpx_detected = true;
+		/*
+		 * On some systems hotplug events are generated for the device
+		 * being switched off when ATPX is executed.  They cause ACPI
+		 * hotplug to trigger and attempt to remove the device from
+		 * the system, which causes it to break down.  Prevent that from
+		 * happening by setting the no_hotplug flag for the involved
+		 * ACPI device objects.
+		 */
+		acpi_bus_no_hotplug(radeon_atpx_priv.dhandle);
+		acpi_bus_no_hotplug(radeon_atpx_priv.other_handle);
 		return true;
 	}
 	return false;

drivers/pci/hotplug/acpiphp_glue.c

@@ -279,7 +279,9 @@ static acpi_status register_slot(acpi_handle handle, u32 lvl, void *data,
 
 	status = acpi_evaluate_integer(handle, "_ADR", NULL, &adr);
 	if (ACPI_FAILURE(status)) {
-		acpi_handle_warn(handle, "can't evaluate _ADR (%#x)\n", status);
+		if (status != AE_NOT_FOUND)
+			acpi_handle_warn(handle,
+				"can't evaluate _ADR (%#x)\n", status);
 		return AE_OK;
 	}
 
@@ -643,6 +645,24 @@ static void disable_slot(struct acpiphp_slot *slot)
 	slot->flags &= (~SLOT_ENABLED);
 }
 
+static bool acpiphp_no_hotplug(acpi_handle handle)
+{
+	struct acpi_device *adev = NULL;
+
+	acpi_bus_get_device(handle, &adev);
+	return adev && adev->flags.no_hotplug;
+}
+
+static bool slot_no_hotplug(struct acpiphp_slot *slot)
+{
+	struct acpiphp_func *func;
+
+	list_for_each_entry(func, &slot->funcs, sibling)
+		if (acpiphp_no_hotplug(func_to_handle(func)))
+			return true;
+
+	return false;
+}
 
 /**
  * get_slot_status - get ACPI slot status
@@ -701,7 +721,8 @@ static void trim_stale_devices(struct pci_dev *dev)
 		unsigned long long sta;
 
 		status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
-		alive = ACPI_SUCCESS(status) && sta == ACPI_STA_ALL;
+		alive = (ACPI_SUCCESS(status) && sta == ACPI_STA_ALL)
+			|| acpiphp_no_hotplug(handle);
 	}
 	if (!alive) {
 		u32 v;
@@ -741,8 +762,9 @@ static void acpiphp_check_bridge(struct acpiphp_bridge *bridge)
 		struct pci_dev *dev, *tmp;
 
 		mutex_lock(&slot->crit_sect);
-		/* wake up all functions */
-		if (get_slot_status(slot) == ACPI_STA_ALL) {
+		if (slot_no_hotplug(slot)) {
+			; /* do nothing */
+		} else if (get_slot_status(slot) == ACPI_STA_ALL) {
 			/* remove stale devices if any */
 			list_for_each_entry_safe(dev, tmp, &bus->devices,
 						 bus_list)

drivers/pci/pci-acpi.c

@@ -330,29 +330,32 @@ static int acpi_pci_find_device(struct device *dev, acpi_handle *handle)
 static void pci_acpi_setup(struct device *dev)
 {
 	struct pci_dev *pci_dev = to_pci_dev(dev);
-	acpi_handle handle = ACPI_HANDLE(dev);
-	struct acpi_device *adev;
+	struct acpi_device *adev = ACPI_COMPANION(dev);
 
-	if (acpi_bus_get_device(handle, &adev) || !adev->wakeup.flags.valid)
+	if (!adev)
+		return;
+
+	pci_acpi_add_pm_notifier(adev, pci_dev);
+	if (!adev->wakeup.flags.valid)
 		return;
 
 	device_set_wakeup_capable(dev, true);
 	acpi_pci_sleep_wake(pci_dev, false);
-
-	pci_acpi_add_pm_notifier(adev, pci_dev);
 	if (adev->wakeup.flags.run_wake)
 		device_set_run_wake(dev, true);
 }
 
 static void pci_acpi_cleanup(struct device *dev)
 {
-	acpi_handle handle = ACPI_HANDLE(dev);
-	struct acpi_device *adev;
+	struct acpi_device *adev = ACPI_COMPANION(dev);
 
-	if (!acpi_bus_get_device(handle, &adev) && adev->wakeup.flags.valid) {
+	if (!adev)
+		return;
+
+	pci_acpi_remove_pm_notifier(adev);
+	if (adev->wakeup.flags.valid) {
 		device_set_wakeup_capable(dev, false);
 		device_set_run_wake(dev, false);
-		pci_acpi_remove_pm_notifier(adev);
 	}
 }
 

include/acpi/acpi_bus.h

@@ -169,7 +169,8 @@ struct acpi_device_flags {
 	u32 ejectable:1;
 	u32 power_manageable:1;
 	u32 match_driver:1;
-	u32 reserved:27;
+	u32 no_hotplug:1;
+	u32 reserved:26;
 };
 
 /* File System */
@@ -344,6 +345,7 @@ extern struct kobject *acpi_kobj;
 extern int acpi_bus_generate_netlink_event(const char*, const char*, u8, int);
 void acpi_bus_private_data_handler(acpi_handle, void *);
 int acpi_bus_get_private_data(acpi_handle, void **);
+void acpi_bus_no_hotplug(acpi_handle handle);
 extern int acpi_notifier_call_chain(struct acpi_device *, u32, u32);
 extern int register_acpi_notifier(struct notifier_block *);
 extern int unregister_acpi_notifier(struct notifier_block *);