Adding upstream version 4.19.249.upstream/4.19.249

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

1 files changed, 872 insertions, 0 deletions

diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
new file mode 100644
index 000000000..2c46f7dcd
--- /dev/null
+++ b/drivers/pci/pci-acpi.c
@@ -0,0 +1,872 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCI support in ACPI
+ *
+ * Copyright (C) 2005 David Shaohua Li <shaohua.li@intel.com>
+ * Copyright (C) 2004 Tom Long Nguyen <tom.l.nguyen@intel.com>
+ * Copyright (C) 2004 Intel Corp.
+ */
+
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/irqdomain.h>
+#include <linux/pci.h>
+#include <linux/msi.h>
+#include <linux/pci_hotplug.h>
+#include <linux/module.h>
+#include <linux/pci-aspm.h>
+#include <linux/pci-acpi.h>
+#include <linux/pm_runtime.h>
+#include <linux/pm_qos.h>
+#include "pci.h"
+
+/*
+ * The GUID is defined in the PCI Firmware Specification available here:
+ * https://www.pcisig.com/members/downloads/pcifw_r3_1_13Dec10.pdf
+ */
+const guid_t pci_acpi_dsm_guid =
+	GUID_INIT(0xe5c937d0, 0x3553, 0x4d7a,
+		  0x91, 0x17, 0xea, 0x4d, 0x19, 0xc3, 0x43, 0x4d);
+
+#if defined(CONFIG_PCI_QUIRKS) && defined(CONFIG_ARM64)
+static int acpi_get_rc_addr(struct acpi_device *adev, struct resource *res)
+{
+	struct device *dev = &adev->dev;
+	struct resource_entry *entry;
+	struct list_head list;
+	unsigned long flags;
+	int ret;
+
+	INIT_LIST_HEAD(&list);
+	flags = IORESOURCE_MEM;
+	ret = acpi_dev_get_resources(adev, &list,
+				     acpi_dev_filter_resource_type_cb,
+				     (void *) flags);
+	if (ret < 0) {
+		dev_err(dev, "failed to parse _CRS method, error code %d\n",
+			ret);
+		return ret;
+	}
+
+	if (ret == 0) {
+		dev_err(dev, "no IO and memory resources present in _CRS\n");
+		return -EINVAL;
+	}
+
+	entry = list_first_entry(&list, struct resource_entry, node);
+	*res = *entry->res;
+	acpi_dev_free_resource_list(&list);
+	return 0;
+}
+
+static acpi_status acpi_match_rc(acpi_handle handle, u32 lvl, void *context,
+				 void **retval)
+{
+	u16 *segment = context;
+	unsigned long long uid;
+	acpi_status status;
+
+	status = acpi_evaluate_integer(handle, "_UID", NULL, &uid);
+	if (ACPI_FAILURE(status) || uid != *segment)
+		return AE_CTRL_DEPTH;
+
+	*(acpi_handle *)retval = handle;
+	return AE_CTRL_TERMINATE;
+}
+
+int acpi_get_rc_resources(struct device *dev, const char *hid, u16 segment,
+			  struct resource *res)
+{
+	struct acpi_device *adev;
+	acpi_status status;
+	acpi_handle handle;
+	int ret;
+
+	status = acpi_get_devices(hid, acpi_match_rc, &segment, &handle);
+	if (ACPI_FAILURE(status)) {
+		dev_err(dev, "can't find _HID %s device to locate resources\n",
+			hid);
+		return -ENODEV;
+	}
+
+	ret = acpi_bus_get_device(handle, &adev);
+	if (ret)
+		return ret;
+
+	ret = acpi_get_rc_addr(adev, res);
+	if (ret) {
+		dev_err(dev, "can't get resource from %s\n",
+			dev_name(&adev->dev));
+		return ret;
+	}
+
+	return 0;
+}
+#endif
+
+phys_addr_t acpi_pci_root_get_mcfg_addr(acpi_handle handle)
+{
+	acpi_status status = AE_NOT_EXIST;
+	unsigned long long mcfg_addr;
+
+	if (handle)
+		status = acpi_evaluate_integer(handle, METHOD_NAME__CBA,
+					       NULL, &mcfg_addr);
+	if (ACPI_FAILURE(status))
+		return 0;
+
+	return (phys_addr_t)mcfg_addr;
+}
+
+static acpi_status decode_type0_hpx_record(union acpi_object *record,
+					   struct hotplug_params *hpx)
+{
+	int i;
+	union acpi_object *fields = record->package.elements;
+	u32 revision = fields[1].integer.value;
+
+	switch (revision) {
+	case 1:
+		if (record->package.count != 6)
+			return AE_ERROR;
+		for (i = 2; i < 6; i++)
+			if (fields[i].type != ACPI_TYPE_INTEGER)
+				return AE_ERROR;
+		hpx->t0 = &hpx->type0_data;
+		hpx->t0->revision        = revision;
+		hpx->t0->cache_line_size = fields[2].integer.value;
+		hpx->t0->latency_timer   = fields[3].integer.value;
+		hpx->t0->enable_serr     = fields[4].integer.value;
+		hpx->t0->enable_perr     = fields[5].integer.value;
+		break;
+	default:
+		printk(KERN_WARNING
+		       "%s: Type 0 Revision %d record not supported\n",
+		       __func__, revision);
+		return AE_ERROR;
+	}
+	return AE_OK;
+}
+
+static acpi_status decode_type1_hpx_record(union acpi_object *record,
+					   struct hotplug_params *hpx)
+{
+	int i;
+	union acpi_object *fields = record->package.elements;
+	u32 revision = fields[1].integer.value;
+
+	switch (revision) {
+	case 1:
+		if (record->package.count != 5)
+			return AE_ERROR;
+		for (i = 2; i < 5; i++)
+			if (fields[i].type != ACPI_TYPE_INTEGER)
+				return AE_ERROR;
+		hpx->t1 = &hpx->type1_data;
+		hpx->t1->revision      = revision;
+		hpx->t1->max_mem_read  = fields[2].integer.value;
+		hpx->t1->avg_max_split = fields[3].integer.value;
+		hpx->t1->tot_max_split = fields[4].integer.value;
+		break;
+	default:
+		printk(KERN_WARNING
+		       "%s: Type 1 Revision %d record not supported\n",
+		       __func__, revision);
+		return AE_ERROR;
+	}
+	return AE_OK;
+}
+
+static acpi_status decode_type2_hpx_record(union acpi_object *record,
+					   struct hotplug_params *hpx)
+{
+	int i;
+	union acpi_object *fields = record->package.elements;
+	u32 revision = fields[1].integer.value;
+
+	switch (revision) {
+	case 1:
+		if (record->package.count != 18)
+			return AE_ERROR;
+		for (i = 2; i < 18; i++)
+			if (fields[i].type != ACPI_TYPE_INTEGER)
+				return AE_ERROR;
+		hpx->t2 = &hpx->type2_data;
+		hpx->t2->revision      = revision;
+		hpx->t2->unc_err_mask_and      = fields[2].integer.value;
+		hpx->t2->unc_err_mask_or       = fields[3].integer.value;
+		hpx->t2->unc_err_sever_and     = fields[4].integer.value;
+		hpx->t2->unc_err_sever_or      = fields[5].integer.value;
+		hpx->t2->cor_err_mask_and      = fields[6].integer.value;
+		hpx->t2->cor_err_mask_or       = fields[7].integer.value;
+		hpx->t2->adv_err_cap_and       = fields[8].integer.value;
+		hpx->t2->adv_err_cap_or        = fields[9].integer.value;
+		hpx->t2->pci_exp_devctl_and    = fields[10].integer.value;
+		hpx->t2->pci_exp_devctl_or     = fields[11].integer.value;
+		hpx->t2->pci_exp_lnkctl_and    = fields[12].integer.value;
+		hpx->t2->pci_exp_lnkctl_or     = fields[13].integer.value;
+		hpx->t2->sec_unc_err_sever_and = fields[14].integer.value;
+		hpx->t2->sec_unc_err_sever_or  = fields[15].integer.value;
+		hpx->t2->sec_unc_err_mask_and  = fields[16].integer.value;
+		hpx->t2->sec_unc_err_mask_or   = fields[17].integer.value;
+		break;
+	default:
+		printk(KERN_WARNING
+		       "%s: Type 2 Revision %d record not supported\n",
+		       __func__, revision);
+		return AE_ERROR;
+	}
+	return AE_OK;
+}
+
+static acpi_status acpi_run_hpx(acpi_handle handle, struct hotplug_params *hpx)
+{
+	acpi_status status;
+	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
+	union acpi_object *package, *record, *fields;
+	u32 type;
+	int i;
+
+	/* Clear the return buffer with zeros */
+	memset(hpx, 0, sizeof(struct hotplug_params));
+
+	status = acpi_evaluate_object(handle, "_HPX", NULL, &buffer);
+	if (ACPI_FAILURE(status))
+		return status;
+
+	package = (union acpi_object *)buffer.pointer;
+	if (package->type != ACPI_TYPE_PACKAGE) {
+		status = AE_ERROR;
+		goto exit;
+	}
+
+	for (i = 0; i < package->package.count; i++) {
+		record = &package->package.elements[i];
+		if (record->type != ACPI_TYPE_PACKAGE) {
+			status = AE_ERROR;
+			goto exit;
+		}
+
+		fields = record->package.elements;
+		if (fields[0].type != ACPI_TYPE_INTEGER ||
+		    fields[1].type != ACPI_TYPE_INTEGER) {
+			status = AE_ERROR;
+			goto exit;
+		}
+
+		type = fields[0].integer.value;
+		switch (type) {
+		case 0:
+			status = decode_type0_hpx_record(record, hpx);
+			if (ACPI_FAILURE(status))
+				goto exit;
+			break;
+		case 1:
+			status = decode_type1_hpx_record(record, hpx);
+			if (ACPI_FAILURE(status))
+				goto exit;
+			break;
+		case 2:
+			status = decode_type2_hpx_record(record, hpx);
+			if (ACPI_FAILURE(status))
+				goto exit;
+			break;
+		default:
+			printk(KERN_ERR "%s: Type %d record not supported\n",
+			       __func__, type);
+			status = AE_ERROR;
+			goto exit;
+		}
+	}
+ exit:
+	kfree(buffer.pointer);
+	return status;
+}
+
+static acpi_status acpi_run_hpp(acpi_handle handle, struct hotplug_params *hpp)
+{
+	acpi_status status;
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	union acpi_object *package, *fields;
+	int i;
+
+	memset(hpp, 0, sizeof(struct hotplug_params));
+
+	status = acpi_evaluate_object(handle, "_HPP", NULL, &buffer);
+	if (ACPI_FAILURE(status))
+		return status;
+
+	package = (union acpi_object *) buffer.pointer;
+	if (package->type != ACPI_TYPE_PACKAGE ||
+	    package->package.count != 4) {
+		status = AE_ERROR;
+		goto exit;
+	}
+
+	fields = package->package.elements;
+	for (i = 0; i < 4; i++) {
+		if (fields[i].type != ACPI_TYPE_INTEGER) {
+			status = AE_ERROR;
+			goto exit;
+		}
+	}
+
+	hpp->t0 = &hpp->type0_data;
+	hpp->t0->revision        = 1;
+	hpp->t0->cache_line_size = fields[0].integer.value;
+	hpp->t0->latency_timer   = fields[1].integer.value;
+	hpp->t0->enable_serr     = fields[2].integer.value;
+	hpp->t0->enable_perr     = fields[3].integer.value;
+
+exit:
+	kfree(buffer.pointer);
+	return status;
+}
+
+/* pci_get_hp_params
+ *
+ * @dev - the pci_dev for which we want parameters
+ * @hpp - allocated by the caller
+ */
+int pci_get_hp_params(struct pci_dev *dev, struct hotplug_params *hpp)
+{
+	acpi_status status;
+	acpi_handle handle, phandle;
+	struct pci_bus *pbus;
+
+	if (acpi_pci_disabled)
+		return -ENODEV;
+
+	handle = NULL;
+	for (pbus = dev->bus; pbus; pbus = pbus->parent) {
+		handle = acpi_pci_get_bridge_handle(pbus);
+		if (handle)
+			break;
+	}
+
+	/*
+	 * _HPP settings apply to all child buses, until another _HPP is
+	 * encountered. If we don't find an _HPP for the input pci dev,
+	 * look for it in the parent device scope since that would apply to
+	 * this pci dev.
+	 */
+	while (handle) {
+		status = acpi_run_hpx(handle, hpp);
+		if (ACPI_SUCCESS(status))
+			return 0;
+		status = acpi_run_hpp(handle, hpp);
+		if (ACPI_SUCCESS(status))
+			return 0;
+		if (acpi_is_root_bridge(handle))
+			break;
+		status = acpi_get_parent(handle, &phandle);
+		if (ACPI_FAILURE(status))
+			break;
+		handle = phandle;
+	}
+	return -ENODEV;
+}
+EXPORT_SYMBOL_GPL(pci_get_hp_params);
+
+/**
+ * pciehp_is_native - Check whether a hotplug port is handled by the OS
+ * @bridge: Hotplug port to check
+ *
+ * Returns true if the given @bridge is handled by the native PCIe hotplug
+ * driver.
+ */
+bool pciehp_is_native(struct pci_dev *bridge)
+{
+	const struct pci_host_bridge *host;
+	u32 slot_cap;
+
+	if (!IS_ENABLED(CONFIG_HOTPLUG_PCI_PCIE))
+		return false;
+
+	pcie_capability_read_dword(bridge, PCI_EXP_SLTCAP, &slot_cap);
+	if (!(slot_cap & PCI_EXP_SLTCAP_HPC))
+		return false;
+
+	if (pcie_ports_native)
+		return true;
+
+	host = pci_find_host_bridge(bridge->bus);
+	return host->native_pcie_hotplug;
+}
+
+/**
+ * shpchp_is_native - Check whether a hotplug port is handled by the OS
+ * @bridge: Hotplug port to check
+ *
+ * Returns true if the given @bridge is handled by the native SHPC hotplug
+ * driver.
+ */
+bool shpchp_is_native(struct pci_dev *bridge)
+{
+	return bridge->shpc_managed;
+}
+
+/**
+ * pci_acpi_wake_bus - Root bus wakeup notification fork function.
+ * @context: Device wakeup context.
+ */
+static void pci_acpi_wake_bus(struct acpi_device_wakeup_context *context)
+{
+	struct acpi_device *adev;
+	struct acpi_pci_root *root;
+
+	adev = container_of(context, struct acpi_device, wakeup.context);
+	root = acpi_driver_data(adev);
+	pci_pme_wakeup_bus(root->bus);
+}
+
+/**
+ * pci_acpi_wake_dev - PCI device wakeup notification work function.
+ * @context: Device wakeup context.
+ */
+static void pci_acpi_wake_dev(struct acpi_device_wakeup_context *context)
+{
+	struct pci_dev *pci_dev;
+
+	pci_dev = to_pci_dev(context->dev);
+
+	if (pci_dev->pme_poll)
+		pci_dev->pme_poll = false;
+
+	if (pci_dev->current_state == PCI_D3cold) {
+		pci_wakeup_event(pci_dev);
+		pm_request_resume(&pci_dev->dev);
+		return;
+	}
+
+	/* Clear PME Status if set. */
+	if (pci_dev->pme_support)
+		pci_check_pme_status(pci_dev);
+
+	pci_wakeup_event(pci_dev);
+	pm_request_resume(&pci_dev->dev);
+
+	pci_pme_wakeup_bus(pci_dev->subordinate);
+}
+
+/**
+ * pci_acpi_add_bus_pm_notifier - Register PM notifier for root PCI bus.
+ * @dev: PCI root bridge ACPI device.
+ */
+acpi_status pci_acpi_add_bus_pm_notifier(struct acpi_device *dev)
+{
+	return acpi_add_pm_notifier(dev, NULL, pci_acpi_wake_bus);
+}
+
+/**
+ * pci_acpi_add_pm_notifier - Register PM notifier for given PCI device.
+ * @dev: ACPI device to add the notifier for.
+ * @pci_dev: PCI device to check for the PME status if an event is signaled.
+ */
+acpi_status pci_acpi_add_pm_notifier(struct acpi_device *dev,
+				     struct pci_dev *pci_dev)
+{
+	return acpi_add_pm_notifier(dev, &pci_dev->dev, pci_acpi_wake_dev);
+}
+
+/*
+ * _SxD returns the D-state with the highest power
+ * (lowest D-state number) supported in the S-state "x".
+ *
+ * If the devices does not have a _PRW
+ * (Power Resources for Wake) supporting system wakeup from "x"
+ * then the OS is free to choose a lower power (higher number
+ * D-state) than the return value from _SxD.
+ *
+ * But if _PRW is enabled at S-state "x", the OS
+ * must not choose a power lower than _SxD --
+ * unless the device has an _SxW method specifying
+ * the lowest power (highest D-state number) the device
+ * may enter while still able to wake the system.
+ *
+ * ie. depending on global OS policy:
+ *
+ * if (_PRW at S-state x)
+ *	choose from highest power _SxD to lowest power _SxW
+ * else // no _PRW at S-state x
+ *	choose highest power _SxD or any lower power
+ */
+
+static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev)
+{
+	int acpi_state, d_max;
+
+	if (pdev->no_d3cold)
+		d_max = ACPI_STATE_D3_HOT;
+	else
+		d_max = ACPI_STATE_D3_COLD;
+	acpi_state = acpi_pm_device_sleep_state(&pdev->dev, NULL, d_max);
+	if (acpi_state < 0)
+		return PCI_POWER_ERROR;
+
+	switch (acpi_state) {
+	case ACPI_STATE_D0:
+		return PCI_D0;
+	case ACPI_STATE_D1:
+		return PCI_D1;
+	case ACPI_STATE_D2:
+		return PCI_D2;
+	case ACPI_STATE_D3_HOT:
+		return PCI_D3hot;
+	case ACPI_STATE_D3_COLD:
+		return PCI_D3cold;
+	}
+	return PCI_POWER_ERROR;
+}
+
+static bool acpi_pci_power_manageable(struct pci_dev *dev)
+{
+	struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
+	return adev ? acpi_device_power_manageable(adev) : false;
+}
+
+static int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
+{
+	struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
+	static const u8 state_conv[] = {
+		[PCI_D0] = ACPI_STATE_D0,
+		[PCI_D1] = ACPI_STATE_D1,
+		[PCI_D2] = ACPI_STATE_D2,
+		[PCI_D3hot] = ACPI_STATE_D3_HOT,
+		[PCI_D3cold] = ACPI_STATE_D3_COLD,
+	};
+	int error = -EINVAL;
+
+	/* If the ACPI device has _EJ0, ignore the device */
+	if (!adev || acpi_has_method(adev->handle, "_EJ0"))
+		return -ENODEV;
+
+	switch (state) {
+	case PCI_D3cold:
+		if (dev_pm_qos_flags(&dev->dev, PM_QOS_FLAG_NO_POWER_OFF) ==
+				PM_QOS_FLAGS_ALL) {
+			error = -EBUSY;
+			break;
+		}
+	case PCI_D0:
+	case PCI_D1:
+	case PCI_D2:
+	case PCI_D3hot:
+		error = acpi_device_set_power(adev, state_conv[state]);
+	}
+
+	if (!error)
+		pci_dbg(dev, "power state changed by ACPI to %s\n",
+			 acpi_power_state_string(state_conv[state]));
+
+	return error;
+}
+
+static pci_power_t acpi_pci_get_power_state(struct pci_dev *dev)
+{
+	struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
+	static const pci_power_t state_conv[] = {
+		[ACPI_STATE_D0]      = PCI_D0,
+		[ACPI_STATE_D1]      = PCI_D1,
+		[ACPI_STATE_D2]      = PCI_D2,
+		[ACPI_STATE_D3_HOT]  = PCI_D3hot,
+		[ACPI_STATE_D3_COLD] = PCI_D3cold,
+	};
+	int state;
+
+	if (!adev || !acpi_device_power_manageable(adev))
+		return PCI_UNKNOWN;
+
+	if (acpi_device_get_power(adev, &state) || state == ACPI_STATE_UNKNOWN)
+		return PCI_UNKNOWN;
+
+	return state_conv[state];
+}
+
+static int acpi_pci_propagate_wakeup(struct pci_bus *bus, bool enable)
+{
+	while (bus->parent) {
+		if (acpi_pm_device_can_wakeup(&bus->self->dev))
+			return acpi_pm_set_device_wakeup(&bus->self->dev, enable);
+
+		bus = bus->parent;
+	}
+
+	/* We have reached the root bus. */
+	if (bus->bridge) {
+		if (acpi_pm_device_can_wakeup(bus->bridge))
+			return acpi_pm_set_device_wakeup(bus->bridge, enable);
+	}
+	return 0;
+}
+
+static int acpi_pci_wakeup(struct pci_dev *dev, bool enable)
+{
+	if (acpi_pm_device_can_wakeup(&dev->dev))
+		return acpi_pm_set_device_wakeup(&dev->dev, enable);
+
+	return acpi_pci_propagate_wakeup(dev->bus, enable);
+}
+
+static bool acpi_pci_need_resume(struct pci_dev *dev)
+{
+	struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
+
+	/*
+	 * In some cases (eg. Samsung 305V4A) leaving a bridge in suspend over
+	 * system-wide suspend/resume confuses the platform firmware, so avoid
+	 * doing that.  According to Section 16.1.6 of ACPI 6.2, endpoint
+	 * devices are expected to be in D3 before invoking the S3 entry path
+	 * from the firmware, so they should not be affected by this issue.
+	 */
+	if (pci_is_bridge(dev) && acpi_target_system_state() != ACPI_STATE_S0)
+		return true;
+
+	if (!adev || !acpi_device_power_manageable(adev))
+		return false;
+
+	if (adev->wakeup.flags.valid &&
+	    device_may_wakeup(&dev->dev) != !!adev->wakeup.prepare_count)
+		return true;
+
+	if (acpi_target_system_state() == ACPI_STATE_S0)
+		return false;
+
+	return !!adev->power.flags.dsw_present;
+}
+
+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,
+	.choose_state = acpi_pci_choose_state,
+	.set_wakeup = acpi_pci_wakeup,
+	.need_resume = acpi_pci_need_resume,
+};
+
+void acpi_pci_add_bus(struct pci_bus *bus)
+{
+	union acpi_object *obj;
+	struct pci_host_bridge *bridge;
+
+	if (acpi_pci_disabled || !bus->bridge || !ACPI_HANDLE(bus->bridge))
+		return;
+
+	acpi_pci_slot_enumerate(bus);
+	acpiphp_enumerate_slots(bus);
+
+	/*
+	 * For a host bridge, check its _DSM for function 8 and if
+	 * that is available, mark it in pci_host_bridge.
+	 */
+	if (!pci_is_root_bus(bus))
+		return;
+
+	obj = acpi_evaluate_dsm(ACPI_HANDLE(bus->bridge), &pci_acpi_dsm_guid, 3,
+				RESET_DELAY_DSM, NULL);
+	if (!obj)
+		return;
+
+	if (obj->type == ACPI_TYPE_INTEGER && obj->integer.value == 1) {
+		bridge = pci_find_host_bridge(bus);
+		bridge->ignore_reset_delay = 1;
+	}
+	ACPI_FREE(obj);
+}
+
+void acpi_pci_remove_bus(struct pci_bus *bus)
+{
+	if (acpi_pci_disabled || !bus->bridge)
+		return;
+
+	acpiphp_remove_slots(bus);
+	acpi_pci_slot_remove(bus);
+}
+
+/* ACPI bus type */
+static struct acpi_device *acpi_pci_find_companion(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	bool check_children;
+	u64 addr;
+
+	check_children = pci_is_bridge(pci_dev);
+	/* Please ref to ACPI spec for the syntax of _ADR */
+	addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn);
+	return acpi_find_child_device(ACPI_COMPANION(dev->parent), addr,
+				      check_children);
+}
+
+/**
+ * pci_acpi_optimize_delay - optimize PCI D3 and D3cold delay from ACPI
+ * @pdev: the PCI device whose delay is to be updated
+ * @handle: ACPI handle of this device
+ *
+ * Update the d3_delay and d3cold_delay of a PCI device from the ACPI _DSM
+ * control method of either the device itself or the PCI host bridge.
+ *
+ * Function 8, "Reset Delay," applies to the entire hierarchy below a PCI
+ * host bridge.  If it returns one, the OS may assume that all devices in
+ * the hierarchy have already completed power-on reset delays.
+ *
+ * Function 9, "Device Readiness Durations," applies only to the object
+ * where it is located.  It returns delay durations required after various
+ * events if the device requires less time than the spec requires.  Delays
+ * from this function take precedence over the Reset Delay function.
+ *
+ * These _DSM functions are defined by the draft ECN of January 28, 2014,
+ * titled "ACPI additions for FW latency optimizations."
+ */
+static void pci_acpi_optimize_delay(struct pci_dev *pdev,
+				    acpi_handle handle)
+{
+	struct pci_host_bridge *bridge = pci_find_host_bridge(pdev->bus);
+	int value;
+	union acpi_object *obj, *elements;
+
+	if (bridge->ignore_reset_delay)
+		pdev->d3cold_delay = 0;
+
+	obj = acpi_evaluate_dsm(handle, &pci_acpi_dsm_guid, 3,
+				FUNCTION_DELAY_DSM, NULL);
+	if (!obj)
+		return;
+
+	if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 5) {
+		elements = obj->package.elements;
+		if (elements[0].type == ACPI_TYPE_INTEGER) {
+			value = (int)elements[0].integer.value / 1000;
+			if (value < PCI_PM_D3COLD_WAIT)
+				pdev->d3cold_delay = value;
+		}
+		if (elements[3].type == ACPI_TYPE_INTEGER) {
+			value = (int)elements[3].integer.value / 1000;
+			if (value < PCI_PM_D3_WAIT)
+				pdev->d3_delay = value;
+		}
+	}
+	ACPI_FREE(obj);
+}
+
+static void pci_acpi_setup(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	struct acpi_device *adev = ACPI_COMPANION(dev);
+
+	if (!adev)
+		return;
+
+	pci_acpi_optimize_delay(pci_dev, adev->handle);
+
+	pci_acpi_add_pm_notifier(adev, pci_dev);
+	if (!adev->wakeup.flags.valid)
+		return;
+
+	device_set_wakeup_capable(dev, true);
+	/*
+	 * For bridges that can do D3 we enable wake automatically (as
+	 * we do for the power management itself in that case). The
+	 * reason is that the bridge may have additional methods such as
+	 * _DSW that need to be called.
+	 */
+	if (pci_dev->bridge_d3)
+		device_wakeup_enable(dev);
+
+	acpi_pci_wakeup(pci_dev, false);
+}
+
+static void pci_acpi_cleanup(struct device *dev)
+{
+	struct acpi_device *adev = ACPI_COMPANION(dev);
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+
+	if (!adev)
+		return;
+
+	pci_acpi_remove_pm_notifier(adev);
+	if (adev->wakeup.flags.valid) {
+		if (pci_dev->bridge_d3)
+			device_wakeup_disable(dev);
+
+		device_set_wakeup_capable(dev, false);
+	}
+}
+
+static bool pci_acpi_bus_match(struct device *dev)
+{
+	return dev_is_pci(dev);
+}
+
+static struct acpi_bus_type acpi_pci_bus = {
+	.name = "PCI",
+	.match = pci_acpi_bus_match,
+	.find_companion = acpi_pci_find_companion,
+	.setup = pci_acpi_setup,
+	.cleanup = pci_acpi_cleanup,
+};
+
+
+static struct fwnode_handle *(*pci_msi_get_fwnode_cb)(struct device *dev);
+
+/**
+ * pci_msi_register_fwnode_provider - Register callback to retrieve fwnode
+ * @fn:       Callback matching a device to a fwnode that identifies a PCI
+ *            MSI domain.
+ *
+ * This should be called by irqchip driver, which is the parent of
+ * the MSI domain to provide callback interface to query fwnode.
+ */
+void
+pci_msi_register_fwnode_provider(struct fwnode_handle *(*fn)(struct device *))
+{
+	pci_msi_get_fwnode_cb = fn;
+}
+
+/**
+ * pci_host_bridge_acpi_msi_domain - Retrieve MSI domain of a PCI host bridge
+ * @bus:      The PCI host bridge bus.
+ *
+ * This function uses the callback function registered by
+ * pci_msi_register_fwnode_provider() to retrieve the irq_domain with
+ * type DOMAIN_BUS_PCI_MSI of the specified host bridge bus.
+ * This returns NULL on error or when the domain is not found.
+ */
+struct irq_domain *pci_host_bridge_acpi_msi_domain(struct pci_bus *bus)
+{
+	struct fwnode_handle *fwnode;
+
+	if (!pci_msi_get_fwnode_cb)
+		return NULL;
+
+	fwnode = pci_msi_get_fwnode_cb(&bus->dev);
+	if (!fwnode)
+		return NULL;
+
+	return irq_find_matching_fwnode(fwnode, DOMAIN_BUS_PCI_MSI);
+}
+
+static int __init acpi_pci_init(void)
+{
+	int ret;
+
+	if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_MSI) {
+		pr_info("ACPI FADT declares the system doesn't support MSI, so disable it\n");
+		pci_no_msi();
+	}
+
+	if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
+		pr_info("ACPI FADT declares the system doesn't support PCIe ASPM, so disable it\n");
+		pcie_no_aspm();
+	}
+
+	ret = register_acpi_bus_type(&acpi_pci_bus);
+	if (ret)
+		return 0;
+
+	pci_set_platform_pm(&acpi_pci_platform_pm);
+	acpi_pci_slot_init();
+	acpiphp_init();
+
+	return 0;
+}
+arch_initcall(acpi_pci_init);