Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1059 insertions, 0 deletions

diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c
new file mode 100644
index 000000000..f031302ad
--- /dev/null
+++ b/drivers/pci/hotplug/acpiphp_glue.c
@@ -0,0 +1,1059 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * ACPI PCI HotPlug glue functions to ACPI CA subsystem
+ *
+ * Copyright (C) 2002,2003 Takayoshi Kochi (t-kochi@bq.jp.nec.com)
+ * Copyright (C) 2002 Hiroshi Aono (h-aono@ap.jp.nec.com)
+ * Copyright (C) 2002,2003 NEC Corporation
+ * Copyright (C) 2003-2005 Matthew Wilcox (willy@infradead.org)
+ * Copyright (C) 2003-2005 Hewlett Packard
+ * Copyright (C) 2005 Rajesh Shah (rajesh.shah@intel.com)
+ * Copyright (C) 2005 Intel Corporation
+ *
+ * All rights reserved.
+ *
+ * Send feedback to <kristen.c.accardi@intel.com>
+ *
+ */
+
+/*
+ * Lifetime rules for pci_dev:
+ *  - The one in acpiphp_bridge has its refcount elevated by pci_get_slot()
+ *    when the bridge is scanned and it loses a refcount when the bridge
+ *    is removed.
+ *  - When a P2P bridge is present, we elevate the refcount on the subordinate
+ *    bus. It loses the refcount when the the driver unloads.
+ */
+
+#define pr_fmt(fmt) "acpiphp_glue: " fmt
+
+#include <linux/module.h>
+
+#include <linux/kernel.h>
+#include <linux/pci.h>
+#include <linux/pci_hotplug.h>
+#include <linux/pci-acpi.h>
+#include <linux/pm_runtime.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/acpi.h>
+
+#include "../pci.h"
+#include "acpiphp.h"
+
+static LIST_HEAD(bridge_list);
+static DEFINE_MUTEX(bridge_mutex);
+
+static int acpiphp_hotplug_notify(struct acpi_device *adev, u32 type);
+static void acpiphp_post_dock_fixup(struct acpi_device *adev);
+static void acpiphp_sanitize_bus(struct pci_bus *bus);
+static void hotplug_event(u32 type, struct acpiphp_context *context);
+static void free_bridge(struct kref *kref);
+
+/**
+ * acpiphp_init_context - Create hotplug context and grab a reference to it.
+ * @adev: ACPI device object to create the context for.
+ *
+ * Call under acpi_hp_context_lock.
+ */
+static struct acpiphp_context *acpiphp_init_context(struct acpi_device *adev)
+{
+	struct acpiphp_context *context;
+
+	context = kzalloc(sizeof(*context), GFP_KERNEL);
+	if (!context)
+		return NULL;
+
+	context->refcount = 1;
+	context->hp.notify = acpiphp_hotplug_notify;
+	context->hp.fixup = acpiphp_post_dock_fixup;
+	acpi_set_hp_context(adev, &context->hp);
+	return context;
+}
+
+/**
+ * acpiphp_get_context - Get hotplug context and grab a reference to it.
+ * @adev: ACPI device object to get the context for.
+ *
+ * Call under acpi_hp_context_lock.
+ */
+static struct acpiphp_context *acpiphp_get_context(struct acpi_device *adev)
+{
+	struct acpiphp_context *context;
+
+	if (!adev->hp)
+		return NULL;
+
+	context = to_acpiphp_context(adev->hp);
+	context->refcount++;
+	return context;
+}
+
+/**
+ * acpiphp_put_context - Drop a reference to ACPI hotplug context.
+ * @context: ACPI hotplug context to drop a reference to.
+ *
+ * The context object is removed if there are no more references to it.
+ *
+ * Call under acpi_hp_context_lock.
+ */
+static void acpiphp_put_context(struct acpiphp_context *context)
+{
+	if (--context->refcount)
+		return;
+
+	WARN_ON(context->bridge);
+	context->hp.self->hp = NULL;
+	kfree(context);
+}
+
+static inline void get_bridge(struct acpiphp_bridge *bridge)
+{
+	kref_get(&bridge->ref);
+}
+
+static inline void put_bridge(struct acpiphp_bridge *bridge)
+{
+	kref_put(&bridge->ref, free_bridge);
+}
+
+static struct acpiphp_context *acpiphp_grab_context(struct acpi_device *adev)
+{
+	struct acpiphp_context *context;
+
+	acpi_lock_hp_context();
+
+	context = acpiphp_get_context(adev);
+	if (!context)
+		goto unlock;
+
+	if (context->func.parent->is_going_away) {
+		acpiphp_put_context(context);
+		context = NULL;
+		goto unlock;
+	}
+
+	get_bridge(context->func.parent);
+	acpiphp_put_context(context);
+
+unlock:
+	acpi_unlock_hp_context();
+	return context;
+}
+
+static void acpiphp_let_context_go(struct acpiphp_context *context)
+{
+	put_bridge(context->func.parent);
+}
+
+static void free_bridge(struct kref *kref)
+{
+	struct acpiphp_context *context;
+	struct acpiphp_bridge *bridge;
+	struct acpiphp_slot *slot, *next;
+	struct acpiphp_func *func, *tmp;
+
+	acpi_lock_hp_context();
+
+	bridge = container_of(kref, struct acpiphp_bridge, ref);
+
+	list_for_each_entry_safe(slot, next, &bridge->slots, node) {
+		list_for_each_entry_safe(func, tmp, &slot->funcs, sibling)
+			acpiphp_put_context(func_to_context(func));
+
+		kfree(slot);
+	}
+
+	context = bridge->context;
+	/* Root bridges will not have hotplug context. */
+	if (context) {
+		/* Release the reference taken by acpiphp_enumerate_slots(). */
+		put_bridge(context->func.parent);
+		context->bridge = NULL;
+		acpiphp_put_context(context);
+	}
+
+	put_device(&bridge->pci_bus->dev);
+	pci_dev_put(bridge->pci_dev);
+	kfree(bridge);
+
+	acpi_unlock_hp_context();
+}
+
+/**
+ * acpiphp_post_dock_fixup - Post-dock fixups for PCI devices.
+ * @adev: ACPI device object corresponding to a PCI device.
+ *
+ * TBD - figure out a way to only call fixups for systems that require them.
+ */
+static void acpiphp_post_dock_fixup(struct acpi_device *adev)
+{
+	struct acpiphp_context *context = acpiphp_grab_context(adev);
+	struct pci_bus *bus;
+	u32 buses;
+
+	if (!context)
+		return;
+
+	bus = context->func.slot->bus;
+	if (!bus->self)
+		goto out;
+
+	/* fixup bad _DCK function that rewrites
+	 * secondary bridge on slot
+	 */
+	pci_read_config_dword(bus->self, PCI_PRIMARY_BUS, &buses);
+
+	if (((buses >> 8) & 0xff) != bus->busn_res.start) {
+		buses = (buses & 0xff000000)
+			| ((unsigned int)(bus->primary)     <<  0)
+			| ((unsigned int)(bus->busn_res.start)   <<  8)
+			| ((unsigned int)(bus->busn_res.end) << 16);
+		pci_write_config_dword(bus->self, PCI_PRIMARY_BUS, buses);
+	}
+
+ out:
+	acpiphp_let_context_go(context);
+}
+
+/**
+ * acpiphp_add_context - Add ACPIPHP context to an ACPI device object.
+ * @handle: ACPI handle of the object to add a context to.
+ * @lvl: Not used.
+ * @data: The object's parent ACPIPHP bridge.
+ * @rv: Not used.
+ */
+static acpi_status acpiphp_add_context(acpi_handle handle, u32 lvl, void *data,
+				       void **rv)
+{
+	struct acpiphp_bridge *bridge = data;
+	struct acpiphp_context *context;
+	struct acpi_device *adev;
+	struct acpiphp_slot *slot;
+	struct acpiphp_func *newfunc;
+	acpi_status status = AE_OK;
+	unsigned long long adr;
+	int device, function;
+	struct pci_bus *pbus = bridge->pci_bus;
+	struct pci_dev *pdev = bridge->pci_dev;
+	u32 val;
+
+	status = acpi_evaluate_integer(handle, "_ADR", NULL, &adr);
+	if (ACPI_FAILURE(status)) {
+		if (status != AE_NOT_FOUND)
+			acpi_handle_warn(handle,
+				"can't evaluate _ADR (%#x)\n", status);
+		return AE_OK;
+	}
+	if (acpi_bus_get_device(handle, &adev))
+		return AE_OK;
+
+	device = (adr >> 16) & 0xffff;
+	function = adr & 0xffff;
+
+	acpi_lock_hp_context();
+	context = acpiphp_init_context(adev);
+	if (!context) {
+		acpi_unlock_hp_context();
+		acpi_handle_err(handle, "No hotplug context\n");
+		return AE_NOT_EXIST;
+	}
+	newfunc = &context->func;
+	newfunc->function = function;
+	newfunc->parent = bridge;
+	acpi_unlock_hp_context();
+
+	/*
+	 * If this is a dock device, its _EJ0 should be executed by the dock
+	 * notify handler after calling _DCK.
+	 */
+	if (!is_dock_device(adev) && acpi_has_method(handle, "_EJ0"))
+		newfunc->flags = FUNC_HAS_EJ0;
+
+	if (acpi_has_method(handle, "_STA"))
+		newfunc->flags |= FUNC_HAS_STA;
+
+	/* search for objects that share the same slot */
+	list_for_each_entry(slot, &bridge->slots, node)
+		if (slot->device == device)
+			goto slot_found;
+
+	slot = kzalloc(sizeof(struct acpiphp_slot), GFP_KERNEL);
+	if (!slot) {
+		acpi_lock_hp_context();
+		acpiphp_put_context(context);
+		acpi_unlock_hp_context();
+		return AE_NO_MEMORY;
+	}
+
+	slot->bus = bridge->pci_bus;
+	slot->device = device;
+	INIT_LIST_HEAD(&slot->funcs);
+
+	list_add_tail(&slot->node, &bridge->slots);
+
+	/*
+	 * Expose slots to user space for functions that have _EJ0 or _RMV or
+	 * are located in dock stations.  Do not expose them for devices handled
+	 * by the native PCIe hotplug (PCIeHP) or standard PCI hotplug
+	 * (SHPCHP), because that code is supposed to expose slots to user
+	 * space in those cases.
+	 */
+	if ((acpi_pci_check_ejectable(pbus, handle) || is_dock_device(adev))
+	    && !(pdev && hotplug_is_native(pdev))) {
+		unsigned long long sun;
+		int retval;
+
+		bridge->nr_slots++;
+		status = acpi_evaluate_integer(handle, "_SUN", NULL, &sun);
+		if (ACPI_FAILURE(status))
+			sun = bridge->nr_slots;
+
+		pr_debug("found ACPI PCI Hotplug slot %llu at PCI %04x:%02x:%02x\n",
+		    sun, pci_domain_nr(pbus), pbus->number, device);
+
+		retval = acpiphp_register_hotplug_slot(slot, sun);
+		if (retval) {
+			slot->slot = NULL;
+			bridge->nr_slots--;
+			if (retval == -EBUSY)
+				pr_warn("Slot %llu already registered by another hotplug driver\n", sun);
+			else
+				pr_warn("acpiphp_register_hotplug_slot failed (err code = 0x%x)\n", retval);
+		}
+		/* Even if the slot registration fails, we can still use it. */
+	}
+
+ slot_found:
+	newfunc->slot = slot;
+	list_add_tail(&newfunc->sibling, &slot->funcs);
+
+	if (pci_bus_read_dev_vendor_id(pbus, PCI_DEVFN(device, function),
+				       &val, 60*1000))
+		slot->flags |= SLOT_ENABLED;
+
+	return AE_OK;
+}
+
+static void cleanup_bridge(struct acpiphp_bridge *bridge)
+{
+	struct acpiphp_slot *slot;
+	struct acpiphp_func *func;
+
+	list_for_each_entry(slot, &bridge->slots, node) {
+		list_for_each_entry(func, &slot->funcs, sibling) {
+			struct acpi_device *adev = func_to_acpi_device(func);
+
+			acpi_lock_hp_context();
+			adev->hp->notify = NULL;
+			adev->hp->fixup = NULL;
+			acpi_unlock_hp_context();
+		}
+		slot->flags |= SLOT_IS_GOING_AWAY;
+		if (slot->slot)
+			acpiphp_unregister_hotplug_slot(slot);
+	}
+
+	mutex_lock(&bridge_mutex);
+	list_del(&bridge->list);
+	mutex_unlock(&bridge_mutex);
+
+	acpi_lock_hp_context();
+	bridge->is_going_away = true;
+	acpi_unlock_hp_context();
+}
+
+/**
+ * acpiphp_max_busnr - return the highest reserved bus number under the given bus.
+ * @bus: bus to start search with
+ */
+static unsigned char acpiphp_max_busnr(struct pci_bus *bus)
+{
+	struct pci_bus *tmp;
+	unsigned char max, n;
+
+	/*
+	 * pci_bus_max_busnr will return the highest
+	 * reserved busnr for all these children.
+	 * that is equivalent to the bus->subordinate
+	 * value.  We don't want to use the parent's
+	 * bus->subordinate value because it could have
+	 * padding in it.
+	 */
+	max = bus->busn_res.start;
+
+	list_for_each_entry(tmp, &bus->children, node) {
+		n = pci_bus_max_busnr(tmp);
+		if (n > max)
+			max = n;
+	}
+	return max;
+}
+
+static void acpiphp_set_acpi_region(struct acpiphp_slot *slot)
+{
+	struct acpiphp_func *func;
+
+	list_for_each_entry(func, &slot->funcs, sibling) {
+		/* _REG is optional, we don't care about if there is failure */
+		acpi_evaluate_reg(func_to_handle(func),
+				  ACPI_ADR_SPACE_PCI_CONFIG,
+				  ACPI_REG_CONNECT);
+	}
+}
+
+static void check_hotplug_bridge(struct acpiphp_slot *slot, struct pci_dev *dev)
+{
+	struct acpiphp_func *func;
+
+	/* quirk, or pcie could set it already */
+	if (dev->is_hotplug_bridge)
+		return;
+
+	list_for_each_entry(func, &slot->funcs, sibling) {
+		if (PCI_FUNC(dev->devfn) == func->function) {
+			dev->is_hotplug_bridge = 1;
+			break;
+		}
+	}
+}
+
+static int acpiphp_rescan_slot(struct acpiphp_slot *slot)
+{
+	struct acpiphp_func *func;
+
+	list_for_each_entry(func, &slot->funcs, sibling) {
+		struct acpi_device *adev = func_to_acpi_device(func);
+
+		acpi_bus_scan(adev->handle);
+		if (acpi_device_enumerated(adev))
+			acpi_device_set_power(adev, ACPI_STATE_D0);
+	}
+	return pci_scan_slot(slot->bus, PCI_DEVFN(slot->device, 0));
+}
+
+static void acpiphp_native_scan_bridge(struct pci_dev *bridge)
+{
+	struct pci_bus *bus = bridge->subordinate;
+	struct pci_dev *dev;
+	int max;
+
+	if (!bus)
+		return;
+
+	max = bus->busn_res.start;
+	/* Scan already configured non-hotplug bridges */
+	for_each_pci_bridge(dev, bus) {
+		if (!hotplug_is_native(dev))
+			max = pci_scan_bridge(bus, dev, max, 0);
+	}
+
+	/* Scan non-hotplug bridges that need to be reconfigured */
+	for_each_pci_bridge(dev, bus) {
+		if (hotplug_is_native(dev))
+			continue;
+
+		max = pci_scan_bridge(bus, dev, max, 1);
+		if (dev->subordinate) {
+			pcibios_resource_survey_bus(dev->subordinate);
+			pci_bus_size_bridges(dev->subordinate);
+			pci_bus_assign_resources(dev->subordinate);
+		}
+	}
+}
+
+/**
+ * enable_slot - enable, configure a slot
+ * @slot: slot to be enabled
+ * @bridge: true if enable is for the whole bridge (not a single slot)
+ *
+ * This function should be called per *physical slot*,
+ * not per each slot object in ACPI namespace.
+ */
+static void enable_slot(struct acpiphp_slot *slot, bool bridge)
+{
+	struct pci_dev *dev;
+	struct pci_bus *bus = slot->bus;
+	struct acpiphp_func *func;
+
+	if (bridge && bus->self && hotplug_is_native(bus->self)) {
+		/*
+		 * If native hotplug is used, it will take care of hotplug
+		 * slot management and resource allocation for hotplug
+		 * bridges. However, ACPI hotplug may still be used for
+		 * non-hotplug bridges to bring in additional devices such
+		 * as a Thunderbolt host controller.
+		 */
+		for_each_pci_bridge(dev, bus) {
+			if (PCI_SLOT(dev->devfn) == slot->device)
+				acpiphp_native_scan_bridge(dev);
+		}
+	} else {
+		LIST_HEAD(add_list);
+		int max, pass;
+
+		acpiphp_rescan_slot(slot);
+		max = acpiphp_max_busnr(bus);
+		for (pass = 0; pass < 2; pass++) {
+			for_each_pci_bridge(dev, bus) {
+				if (PCI_SLOT(dev->devfn) != slot->device)
+					continue;
+
+				max = pci_scan_bridge(bus, dev, max, pass);
+				if (pass && dev->subordinate) {
+					check_hotplug_bridge(slot, dev);
+					pcibios_resource_survey_bus(dev->subordinate);
+					__pci_bus_size_bridges(dev->subordinate,
+							       &add_list);
+				}
+			}
+		}
+		__pci_bus_assign_resources(bus, &add_list, NULL);
+	}
+
+	acpiphp_sanitize_bus(bus);
+	pcie_bus_configure_settings(bus);
+	acpiphp_set_acpi_region(slot);
+
+	list_for_each_entry(dev, &bus->devices, bus_list) {
+		/* Assume that newly added devices are powered on already. */
+		if (!pci_dev_is_added(dev))
+			dev->current_state = PCI_D0;
+	}
+
+	pci_bus_add_devices(bus);
+
+	slot->flags |= SLOT_ENABLED;
+	list_for_each_entry(func, &slot->funcs, sibling) {
+		dev = pci_get_slot(bus, PCI_DEVFN(slot->device,
+						  func->function));
+		if (!dev) {
+			/* Do not set SLOT_ENABLED flag if some funcs
+			   are not added. */
+			slot->flags &= ~SLOT_ENABLED;
+			continue;
+		}
+		pci_dev_put(dev);
+	}
+}
+
+/**
+ * disable_slot - disable a slot
+ * @slot: ACPI PHP slot
+ */
+static void disable_slot(struct acpiphp_slot *slot)
+{
+	struct pci_bus *bus = slot->bus;
+	struct pci_dev *dev, *prev;
+	struct acpiphp_func *func;
+
+	/*
+	 * enable_slot() enumerates all functions in this device via
+	 * pci_scan_slot(), whether they have associated ACPI hotplug
+	 * methods (_EJ0, etc.) or not.  Therefore, we remove all functions
+	 * here.
+	 */
+	list_for_each_entry_safe_reverse(dev, prev, &bus->devices, bus_list)
+		if (PCI_SLOT(dev->devfn) == slot->device)
+			pci_stop_and_remove_bus_device(dev);
+
+	list_for_each_entry(func, &slot->funcs, sibling)
+		acpi_bus_trim(func_to_acpi_device(func));
+
+	slot->flags &= ~SLOT_ENABLED;
+}
+
+static bool slot_no_hotplug(struct acpiphp_slot *slot)
+{
+	struct pci_bus *bus = slot->bus;
+	struct pci_dev *dev;
+
+	list_for_each_entry(dev, &bus->devices, bus_list) {
+		if (PCI_SLOT(dev->devfn) == slot->device && dev->ignore_hotplug)
+			return true;
+	}
+	return false;
+}
+
+/**
+ * get_slot_status - get ACPI slot status
+ * @slot: ACPI PHP slot
+ *
+ * If a slot has _STA for each function and if any one of them
+ * returned non-zero status, return it.
+ *
+ * If a slot doesn't have _STA and if any one of its functions'
+ * configuration space is configured, return 0x0f as a _STA.
+ *
+ * Otherwise return 0.
+ */
+static unsigned int get_slot_status(struct acpiphp_slot *slot)
+{
+	unsigned long long sta = 0;
+	struct acpiphp_func *func;
+	u32 dvid;
+
+	list_for_each_entry(func, &slot->funcs, sibling) {
+		if (func->flags & FUNC_HAS_STA) {
+			acpi_status status;
+
+			status = acpi_evaluate_integer(func_to_handle(func),
+						       "_STA", NULL, &sta);
+			if (ACPI_SUCCESS(status) && sta)
+				break;
+		} else {
+			if (pci_bus_read_dev_vendor_id(slot->bus,
+					PCI_DEVFN(slot->device, func->function),
+					&dvid, 0)) {
+				sta = ACPI_STA_ALL;
+				break;
+			}
+		}
+	}
+
+	if (!sta) {
+		/*
+		 * Check for the slot itself since it may be that the
+		 * ACPI slot is a device below PCIe upstream port so in
+		 * that case it may not even be reachable yet.
+		 */
+		if (pci_bus_read_dev_vendor_id(slot->bus,
+				PCI_DEVFN(slot->device, 0), &dvid, 0)) {
+			sta = ACPI_STA_ALL;
+		}
+	}
+
+	return (unsigned int)sta;
+}
+
+static inline bool device_status_valid(unsigned int sta)
+{
+	/*
+	 * ACPI spec says that _STA may return bit 0 clear with bit 3 set
+	 * if the device is valid but does not require a device driver to be
+	 * loaded (Section 6.3.7 of ACPI 5.0A).
+	 */
+	unsigned int mask = ACPI_STA_DEVICE_ENABLED | ACPI_STA_DEVICE_FUNCTIONING;
+	return (sta & mask) == mask;
+}
+
+/**
+ * trim_stale_devices - remove PCI devices that are not responding.
+ * @dev: PCI device to start walking the hierarchy from.
+ */
+static void trim_stale_devices(struct pci_dev *dev)
+{
+	struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
+	struct pci_bus *bus = dev->subordinate;
+	bool alive = dev->ignore_hotplug;
+
+	if (adev) {
+		acpi_status status;
+		unsigned long long sta;
+
+		status = acpi_evaluate_integer(adev->handle, "_STA", NULL, &sta);
+		alive = alive || (ACPI_SUCCESS(status) && device_status_valid(sta));
+	}
+	if (!alive)
+		alive = pci_device_is_present(dev);
+
+	if (!alive) {
+		pci_dev_set_disconnected(dev, NULL);
+		if (pci_has_subordinate(dev))
+			pci_walk_bus(dev->subordinate, pci_dev_set_disconnected,
+				     NULL);
+
+		pci_stop_and_remove_bus_device(dev);
+		if (adev)
+			acpi_bus_trim(adev);
+	} else if (bus) {
+		struct pci_dev *child, *tmp;
+
+		/* The device is a bridge. so check the bus below it. */
+		pm_runtime_get_sync(&dev->dev);
+		list_for_each_entry_safe_reverse(child, tmp, &bus->devices, bus_list)
+			trim_stale_devices(child);
+
+		pm_runtime_put(&dev->dev);
+	}
+}
+
+/**
+ * acpiphp_check_bridge - re-enumerate devices
+ * @bridge: where to begin re-enumeration
+ *
+ * Iterate over all slots under this bridge and make sure that if a
+ * card is present they are enabled, and if not they are disabled.
+ */
+static void acpiphp_check_bridge(struct acpiphp_bridge *bridge)
+{
+	struct acpiphp_slot *slot;
+
+	/* Bail out if the bridge is going away. */
+	if (bridge->is_going_away)
+		return;
+
+	if (bridge->pci_dev)
+		pm_runtime_get_sync(&bridge->pci_dev->dev);
+
+	list_for_each_entry(slot, &bridge->slots, node) {
+		struct pci_bus *bus = slot->bus;
+		struct pci_dev *dev, *tmp;
+
+		if (slot_no_hotplug(slot)) {
+			; /* do nothing */
+		} else if (device_status_valid(get_slot_status(slot))) {
+			/* remove stale devices if any */
+			list_for_each_entry_safe_reverse(dev, tmp,
+							 &bus->devices, bus_list)
+				if (PCI_SLOT(dev->devfn) == slot->device)
+					trim_stale_devices(dev);
+
+			/* configure all functions */
+			enable_slot(slot, true);
+		} else {
+			disable_slot(slot);
+		}
+	}
+
+	if (bridge->pci_dev)
+		pm_runtime_put(&bridge->pci_dev->dev);
+}
+
+/*
+ * Remove devices for which we could not assign resources, call
+ * arch specific code to fix-up the bus
+ */
+static void acpiphp_sanitize_bus(struct pci_bus *bus)
+{
+	struct pci_dev *dev, *tmp;
+	int i;
+	unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM;
+
+	list_for_each_entry_safe_reverse(dev, tmp, &bus->devices, bus_list) {
+		for (i = 0; i < PCI_BRIDGE_RESOURCES; i++) {
+			struct resource *res = &dev->resource[i];
+			if ((res->flags & type_mask) && !res->start &&
+					res->end) {
+				/* Could not assign a required resources
+				 * for this device, remove it */
+				pci_stop_and_remove_bus_device(dev);
+				break;
+			}
+		}
+	}
+}
+
+/*
+ * ACPI event handlers
+ */
+
+void acpiphp_check_host_bridge(struct acpi_device *adev)
+{
+	struct acpiphp_bridge *bridge = NULL;
+
+	acpi_lock_hp_context();
+	if (adev->hp) {
+		bridge = to_acpiphp_root_context(adev->hp)->root_bridge;
+		if (bridge)
+			get_bridge(bridge);
+	}
+	acpi_unlock_hp_context();
+	if (bridge) {
+		pci_lock_rescan_remove();
+
+		acpiphp_check_bridge(bridge);
+
+		pci_unlock_rescan_remove();
+		put_bridge(bridge);
+	}
+}
+
+static int acpiphp_disable_and_eject_slot(struct acpiphp_slot *slot);
+
+static void hotplug_event(u32 type, struct acpiphp_context *context)
+{
+	acpi_handle handle = context->hp.self->handle;
+	struct acpiphp_func *func = &context->func;
+	struct acpiphp_slot *slot = func->slot;
+	struct acpiphp_bridge *bridge;
+
+	acpi_lock_hp_context();
+	bridge = context->bridge;
+	if (bridge)
+		get_bridge(bridge);
+
+	acpi_unlock_hp_context();
+
+	pci_lock_rescan_remove();
+
+	switch (type) {
+	case ACPI_NOTIFY_BUS_CHECK:
+		/* bus re-enumerate */
+		acpi_handle_debug(handle, "Bus check in %s()\n", __func__);
+		if (bridge)
+			acpiphp_check_bridge(bridge);
+		else if (!(slot->flags & SLOT_IS_GOING_AWAY))
+			enable_slot(slot, false);
+
+		break;
+
+	case ACPI_NOTIFY_DEVICE_CHECK:
+		/* device check */
+		acpi_handle_debug(handle, "Device check in %s()\n", __func__);
+		if (bridge) {
+			acpiphp_check_bridge(bridge);
+		} else if (!(slot->flags & SLOT_IS_GOING_AWAY)) {
+			/*
+			 * Check if anything has changed in the slot and rescan
+			 * from the parent if that's the case.
+			 */
+			if (acpiphp_rescan_slot(slot))
+				acpiphp_check_bridge(func->parent);
+		}
+		break;
+
+	case ACPI_NOTIFY_EJECT_REQUEST:
+		/* request device eject */
+		acpi_handle_debug(handle, "Eject request in %s()\n", __func__);
+		acpiphp_disable_and_eject_slot(slot);
+		break;
+	}
+
+	pci_unlock_rescan_remove();
+	if (bridge)
+		put_bridge(bridge);
+}
+
+static int acpiphp_hotplug_notify(struct acpi_device *adev, u32 type)
+{
+	struct acpiphp_context *context;
+
+	context = acpiphp_grab_context(adev);
+	if (!context)
+		return -ENODATA;
+
+	hotplug_event(type, context);
+	acpiphp_let_context_go(context);
+	return 0;
+}
+
+/**
+ * acpiphp_enumerate_slots - Enumerate PCI slots for a given bus.
+ * @bus: PCI bus to enumerate the slots for.
+ *
+ * A "slot" is an object associated with a PCI device number.  All functions
+ * (PCI devices) with the same bus and device number belong to the same slot.
+ */
+void acpiphp_enumerate_slots(struct pci_bus *bus)
+{
+	struct acpiphp_bridge *bridge;
+	struct acpi_device *adev;
+	acpi_handle handle;
+	acpi_status status;
+
+	if (acpiphp_disabled)
+		return;
+
+	adev = ACPI_COMPANION(bus->bridge);
+	if (!adev)
+		return;
+
+	handle = adev->handle;
+	bridge = kzalloc(sizeof(struct acpiphp_bridge), GFP_KERNEL);
+	if (!bridge)
+		return;
+
+	INIT_LIST_HEAD(&bridge->slots);
+	kref_init(&bridge->ref);
+	bridge->pci_dev = pci_dev_get(bus->self);
+	bridge->pci_bus = bus;
+
+	/*
+	 * Grab a ref to the subordinate PCI bus in case the bus is
+	 * removed via PCI core logical hotplug. The ref pins the bus
+	 * (which we access during module unload).
+	 */
+	get_device(&bus->dev);
+
+	acpi_lock_hp_context();
+	if (pci_is_root_bus(bridge->pci_bus)) {
+		struct acpiphp_root_context *root_context;
+
+		root_context = kzalloc(sizeof(*root_context), GFP_KERNEL);
+		if (!root_context)
+			goto err;
+
+		root_context->root_bridge = bridge;
+		acpi_set_hp_context(adev, &root_context->hp);
+	} else {
+		struct acpiphp_context *context;
+
+		/*
+		 * This bridge should have been registered as a hotplug function
+		 * under its parent, so the context should be there, unless the
+		 * parent is going to be handled by pciehp, in which case this
+		 * bridge is not interesting to us either.
+		 */
+		context = acpiphp_get_context(adev);
+		if (!context)
+			goto err;
+
+		bridge->context = context;
+		context->bridge = bridge;
+		/* Get a reference to the parent bridge. */
+		get_bridge(context->func.parent);
+	}
+	acpi_unlock_hp_context();
+
+	/* Must be added to the list prior to calling acpiphp_add_context(). */
+	mutex_lock(&bridge_mutex);
+	list_add(&bridge->list, &bridge_list);
+	mutex_unlock(&bridge_mutex);
+
+	/* register all slot objects under this bridge */
+	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
+				     acpiphp_add_context, NULL, bridge, NULL);
+	if (ACPI_FAILURE(status)) {
+		acpi_handle_err(handle, "failed to register slots\n");
+		cleanup_bridge(bridge);
+		put_bridge(bridge);
+	}
+	return;
+
+ err:
+	acpi_unlock_hp_context();
+	put_device(&bus->dev);
+	pci_dev_put(bridge->pci_dev);
+	kfree(bridge);
+}
+
+static void acpiphp_drop_bridge(struct acpiphp_bridge *bridge)
+{
+	if (pci_is_root_bus(bridge->pci_bus)) {
+		struct acpiphp_root_context *root_context;
+		struct acpi_device *adev;
+
+		acpi_lock_hp_context();
+		adev = ACPI_COMPANION(bridge->pci_bus->bridge);
+		root_context = to_acpiphp_root_context(adev->hp);
+		adev->hp = NULL;
+		acpi_unlock_hp_context();
+		kfree(root_context);
+	}
+	cleanup_bridge(bridge);
+	put_bridge(bridge);
+}
+
+/**
+ * acpiphp_remove_slots - Remove slot objects associated with a given bus.
+ * @bus: PCI bus to remove the slot objects for.
+ */
+void acpiphp_remove_slots(struct pci_bus *bus)
+{
+	struct acpiphp_bridge *bridge;
+
+	if (acpiphp_disabled)
+		return;
+
+	mutex_lock(&bridge_mutex);
+	list_for_each_entry(bridge, &bridge_list, list)
+		if (bridge->pci_bus == bus) {
+			mutex_unlock(&bridge_mutex);
+			acpiphp_drop_bridge(bridge);
+			return;
+		}
+
+	mutex_unlock(&bridge_mutex);
+}
+
+/**
+ * acpiphp_enable_slot - power on slot
+ * @slot: ACPI PHP slot
+ */
+int acpiphp_enable_slot(struct acpiphp_slot *slot)
+{
+	pci_lock_rescan_remove();
+
+	if (slot->flags & SLOT_IS_GOING_AWAY) {
+		pci_unlock_rescan_remove();
+		return -ENODEV;
+	}
+
+	/* configure all functions */
+	if (!(slot->flags & SLOT_ENABLED))
+		enable_slot(slot, false);
+
+	pci_unlock_rescan_remove();
+	return 0;
+}
+
+/**
+ * acpiphp_disable_and_eject_slot - power off and eject slot
+ * @slot: ACPI PHP slot
+ */
+static int acpiphp_disable_and_eject_slot(struct acpiphp_slot *slot)
+{
+	struct acpiphp_func *func;
+
+	if (slot->flags & SLOT_IS_GOING_AWAY)
+		return -ENODEV;
+
+	/* unconfigure all functions */
+	disable_slot(slot);
+
+	list_for_each_entry(func, &slot->funcs, sibling)
+		if (func->flags & FUNC_HAS_EJ0) {
+			acpi_handle handle = func_to_handle(func);
+
+			if (ACPI_FAILURE(acpi_evaluate_ej0(handle)))
+				acpi_handle_err(handle, "_EJ0 failed\n");
+
+			break;
+		}
+
+	return 0;
+}
+
+int acpiphp_disable_slot(struct acpiphp_slot *slot)
+{
+	int ret;
+
+	/*
+	 * Acquire acpi_scan_lock to ensure that the execution of _EJ0 in
+	 * acpiphp_disable_and_eject_slot() will be synchronized properly.
+	 */
+	acpi_scan_lock_acquire();
+	pci_lock_rescan_remove();
+	ret = acpiphp_disable_and_eject_slot(slot);
+	pci_unlock_rescan_remove();
+	acpi_scan_lock_release();
+	return ret;
+}
+
+/*
+ * slot enabled:  1
+ * slot disabled: 0
+ */
+u8 acpiphp_get_power_status(struct acpiphp_slot *slot)
+{
+	return (slot->flags & SLOT_ENABLED);
+}
+
+/*
+ * latch   open:  1
+ * latch closed:  0
+ */
+u8 acpiphp_get_latch_status(struct acpiphp_slot *slot)
+{
+	return !(get_slot_status(slot) & ACPI_STA_DEVICE_UI);
+}
+
+/*
+ * adapter presence : 1
+ *          absence : 0
+ */
+u8 acpiphp_get_adapter_status(struct acpiphp_slot *slot)
+{
+	return !!get_slot_status(slot);
+}