Adding upstream version 4.19.249.upstream/4.19.249

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

1 files changed, 943 insertions, 0 deletions

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
new file mode 100644
index 000000000..e465e720e
--- /dev/null
+++ b/drivers/acpi/pci_root.c
@@ -0,0 +1,943 @@
+/*
+ *  pci_root.c - ACPI PCI Root Bridge Driver ($Revision: 40 $)
+ *
+ *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
+ *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or (at
+ *  your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful, but
+ *  WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  General Public License for more details.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/mutex.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
+#include <linux/pci.h>
+#include <linux/pci-acpi.h>
+#include <linux/pci-aspm.h>
+#include <linux/dmar.h>
+#include <linux/acpi.h>
+#include <linux/slab.h>
+#include <linux/dmi.h>
+#include <linux/platform_data/x86/apple.h>
+#include <acpi/apei.h>	/* for acpi_hest_init() */
+
+#include "internal.h"
+
+#define _COMPONENT		ACPI_PCI_COMPONENT
+ACPI_MODULE_NAME("pci_root");
+#define ACPI_PCI_ROOT_CLASS		"pci_bridge"
+#define ACPI_PCI_ROOT_DEVICE_NAME	"PCI Root Bridge"
+static int acpi_pci_root_add(struct acpi_device *device,
+			     const struct acpi_device_id *not_used);
+static void acpi_pci_root_remove(struct acpi_device *device);
+
+static int acpi_pci_root_scan_dependent(struct acpi_device *adev)
+{
+	acpiphp_check_host_bridge(adev);
+	return 0;
+}
+
+#define ACPI_PCIE_REQ_SUPPORT (OSC_PCI_EXT_CONFIG_SUPPORT \
+				| OSC_PCI_ASPM_SUPPORT \
+				| OSC_PCI_CLOCK_PM_SUPPORT \
+				| OSC_PCI_MSI_SUPPORT)
+
+static const struct acpi_device_id root_device_ids[] = {
+	{"PNP0A03", 0},
+	{"", 0},
+};
+
+static struct acpi_scan_handler pci_root_handler = {
+	.ids = root_device_ids,
+	.attach = acpi_pci_root_add,
+	.detach = acpi_pci_root_remove,
+	.hotplug = {
+		.enabled = true,
+		.scan_dependent = acpi_pci_root_scan_dependent,
+	},
+};
+
+static DEFINE_MUTEX(osc_lock);
+
+/**
+ * acpi_is_root_bridge - determine whether an ACPI CA node is a PCI root bridge
+ * @handle - the ACPI CA node in question.
+ *
+ * Note: we could make this API take a struct acpi_device * instead, but
+ * for now, it's more convenient to operate on an acpi_handle.
+ */
+int acpi_is_root_bridge(acpi_handle handle)
+{
+	int ret;
+	struct acpi_device *device;
+
+	ret = acpi_bus_get_device(handle, &device);
+	if (ret)
+		return 0;
+
+	ret = acpi_match_device_ids(device, root_device_ids);
+	if (ret)
+		return 0;
+	else
+		return 1;
+}
+EXPORT_SYMBOL_GPL(acpi_is_root_bridge);
+
+static acpi_status
+get_root_bridge_busnr_callback(struct acpi_resource *resource, void *data)
+{
+	struct resource *res = data;
+	struct acpi_resource_address64 address;
+	acpi_status status;
+
+	status = acpi_resource_to_address64(resource, &address);
+	if (ACPI_FAILURE(status))
+		return AE_OK;
+
+	if ((address.address.address_length > 0) &&
+	    (address.resource_type == ACPI_BUS_NUMBER_RANGE)) {
+		res->start = address.address.minimum;
+		res->end = address.address.minimum + address.address.address_length - 1;
+	}
+
+	return AE_OK;
+}
+
+static acpi_status try_get_root_bridge_busnr(acpi_handle handle,
+					     struct resource *res)
+{
+	acpi_status status;
+
+	res->start = -1;
+	status =
+	    acpi_walk_resources(handle, METHOD_NAME__CRS,
+				get_root_bridge_busnr_callback, res);
+	if (ACPI_FAILURE(status))
+		return status;
+	if (res->start == -1)
+		return AE_ERROR;
+	return AE_OK;
+}
+
+struct pci_osc_bit_struct {
+	u32 bit;
+	char *desc;
+};
+
+static struct pci_osc_bit_struct pci_osc_support_bit[] = {
+	{ OSC_PCI_EXT_CONFIG_SUPPORT, "ExtendedConfig" },
+	{ OSC_PCI_ASPM_SUPPORT, "ASPM" },
+	{ OSC_PCI_CLOCK_PM_SUPPORT, "ClockPM" },
+	{ OSC_PCI_SEGMENT_GROUPS_SUPPORT, "Segments" },
+	{ OSC_PCI_MSI_SUPPORT, "MSI" },
+};
+
+static struct pci_osc_bit_struct pci_osc_control_bit[] = {
+	{ OSC_PCI_EXPRESS_NATIVE_HP_CONTROL, "PCIeHotplug" },
+	{ OSC_PCI_SHPC_NATIVE_HP_CONTROL, "SHPCHotplug" },
+	{ OSC_PCI_EXPRESS_PME_CONTROL, "PME" },
+	{ OSC_PCI_EXPRESS_AER_CONTROL, "AER" },
+	{ OSC_PCI_EXPRESS_CAPABILITY_CONTROL, "PCIeCapability" },
+	{ OSC_PCI_EXPRESS_LTR_CONTROL, "LTR" },
+};
+
+static void decode_osc_bits(struct acpi_pci_root *root, char *msg, u32 word,
+			    struct pci_osc_bit_struct *table, int size)
+{
+	char buf[80];
+	int i, len = 0;
+	struct pci_osc_bit_struct *entry;
+
+	buf[0] = '\0';
+	for (i = 0, entry = table; i < size; i++, entry++)
+		if (word & entry->bit)
+			len += snprintf(buf + len, sizeof(buf) - len, "%s%s",
+					len ? " " : "", entry->desc);
+
+	dev_info(&root->device->dev, "_OSC: %s [%s]\n", msg, buf);
+}
+
+static void decode_osc_support(struct acpi_pci_root *root, char *msg, u32 word)
+{
+	decode_osc_bits(root, msg, word, pci_osc_support_bit,
+			ARRAY_SIZE(pci_osc_support_bit));
+}
+
+static void decode_osc_control(struct acpi_pci_root *root, char *msg, u32 word)
+{
+	decode_osc_bits(root, msg, word, pci_osc_control_bit,
+			ARRAY_SIZE(pci_osc_control_bit));
+}
+
+static u8 pci_osc_uuid_str[] = "33DB4D5B-1FF7-401C-9657-7441C03DD766";
+
+static acpi_status acpi_pci_run_osc(acpi_handle handle,
+				    const u32 *capbuf, u32 *retval)
+{
+	struct acpi_osc_context context = {
+		.uuid_str = pci_osc_uuid_str,
+		.rev = 1,
+		.cap.length = 12,
+		.cap.pointer = (void *)capbuf,
+	};
+	acpi_status status;
+
+	status = acpi_run_osc(handle, &context);
+	if (ACPI_SUCCESS(status)) {
+		*retval = *((u32 *)(context.ret.pointer + 8));
+		kfree(context.ret.pointer);
+	}
+	return status;
+}
+
+static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root,
+					u32 support,
+					u32 *control)
+{
+	acpi_status status;
+	u32 result, capbuf[3];
+
+	support &= OSC_PCI_SUPPORT_MASKS;
+	support |= root->osc_support_set;
+
+	capbuf[OSC_QUERY_DWORD] = OSC_QUERY_ENABLE;
+	capbuf[OSC_SUPPORT_DWORD] = support;
+	if (control) {
+		*control &= OSC_PCI_CONTROL_MASKS;
+		capbuf[OSC_CONTROL_DWORD] = *control | root->osc_control_set;
+	} else {
+		/* Run _OSC query only with existing controls. */
+		capbuf[OSC_CONTROL_DWORD] = root->osc_control_set;
+	}
+
+	status = acpi_pci_run_osc(root->device->handle, capbuf, &result);
+	if (ACPI_SUCCESS(status)) {
+		root->osc_support_set = support;
+		if (control)
+			*control = result;
+	}
+	return status;
+}
+
+static acpi_status acpi_pci_osc_support(struct acpi_pci_root *root, u32 flags)
+{
+	acpi_status status;
+
+	mutex_lock(&osc_lock);
+	status = acpi_pci_query_osc(root, flags, NULL);
+	mutex_unlock(&osc_lock);
+	return status;
+}
+
+struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle)
+{
+	struct acpi_pci_root *root;
+	struct acpi_device *device;
+
+	if (acpi_bus_get_device(handle, &device) ||
+	    acpi_match_device_ids(device, root_device_ids))
+		return NULL;
+
+	root = acpi_driver_data(device);
+
+	return root;
+}
+EXPORT_SYMBOL_GPL(acpi_pci_find_root);
+
+struct acpi_handle_node {
+	struct list_head node;
+	acpi_handle handle;
+};
+
+/**
+ * acpi_get_pci_dev - convert ACPI CA handle to struct pci_dev
+ * @handle: the handle in question
+ *
+ * Given an ACPI CA handle, the desired PCI device is located in the
+ * list of PCI devices.
+ *
+ * If the device is found, its reference count is increased and this
+ * function returns a pointer to its data structure.  The caller must
+ * decrement the reference count by calling pci_dev_put().
+ * If no device is found, %NULL is returned.
+ */
+struct pci_dev *acpi_get_pci_dev(acpi_handle handle)
+{
+	int dev, fn;
+	unsigned long long adr;
+	acpi_status status;
+	acpi_handle phandle;
+	struct pci_bus *pbus;
+	struct pci_dev *pdev = NULL;
+	struct acpi_handle_node *node, *tmp;
+	struct acpi_pci_root *root;
+	LIST_HEAD(device_list);
+
+	/*
+	 * Walk up the ACPI CA namespace until we reach a PCI root bridge.
+	 */
+	phandle = handle;
+	while (!acpi_is_root_bridge(phandle)) {
+		node = kzalloc(sizeof(struct acpi_handle_node), GFP_KERNEL);
+		if (!node)
+			goto out;
+
+		INIT_LIST_HEAD(&node->node);
+		node->handle = phandle;
+		list_add(&node->node, &device_list);
+
+		status = acpi_get_parent(phandle, &phandle);
+		if (ACPI_FAILURE(status))
+			goto out;
+	}
+
+	root = acpi_pci_find_root(phandle);
+	if (!root)
+		goto out;
+
+	pbus = root->bus;
+
+	/*
+	 * Now, walk back down the PCI device tree until we return to our
+	 * original handle. Assumes that everything between the PCI root
+	 * bridge and the device we're looking for must be a P2P bridge.
+	 */
+	list_for_each_entry(node, &device_list, node) {
+		acpi_handle hnd = node->handle;
+		status = acpi_evaluate_integer(hnd, "_ADR", NULL, &adr);
+		if (ACPI_FAILURE(status))
+			goto out;
+		dev = (adr >> 16) & 0xffff;
+		fn  = adr & 0xffff;
+
+		pdev = pci_get_slot(pbus, PCI_DEVFN(dev, fn));
+		if (!pdev || hnd == handle)
+			break;
+
+		pbus = pdev->subordinate;
+		pci_dev_put(pdev);
+
+		/*
+		 * This function may be called for a non-PCI device that has a
+		 * PCI parent (eg. a disk under a PCI SATA controller).  In that
+		 * case pdev->subordinate will be NULL for the parent.
+		 */
+		if (!pbus) {
+			dev_dbg(&pdev->dev, "Not a PCI-to-PCI bridge\n");
+			pdev = NULL;
+			break;
+		}
+	}
+out:
+	list_for_each_entry_safe(node, tmp, &device_list, node)
+		kfree(node);
+
+	return pdev;
+}
+EXPORT_SYMBOL_GPL(acpi_get_pci_dev);
+
+/**
+ * acpi_pci_osc_control_set - Request control of PCI root _OSC features.
+ * @handle: ACPI handle of a PCI root bridge (or PCIe Root Complex).
+ * @mask: Mask of _OSC bits to request control of, place to store control mask.
+ * @req: Mask of _OSC bits the control of is essential to the caller.
+ *
+ * Run _OSC query for @mask and if that is successful, compare the returned
+ * mask of control bits with @req.  If all of the @req bits are set in the
+ * returned mask, run _OSC request for it.
+ *
+ * The variable at the @mask address may be modified regardless of whether or
+ * not the function returns success.  On success it will contain the mask of
+ * _OSC bits the BIOS has granted control of, but its contents are meaningless
+ * on failure.
+ **/
+acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 req)
+{
+	struct acpi_pci_root *root;
+	acpi_status status = AE_OK;
+	u32 ctrl, capbuf[3];
+
+	if (!mask)
+		return AE_BAD_PARAMETER;
+
+	ctrl = *mask & OSC_PCI_CONTROL_MASKS;
+	if ((ctrl & req) != req)
+		return AE_TYPE;
+
+	root = acpi_pci_find_root(handle);
+	if (!root)
+		return AE_NOT_EXIST;
+
+	mutex_lock(&osc_lock);
+
+	*mask = ctrl | root->osc_control_set;
+	/* No need to evaluate _OSC if the control was already granted. */
+	if ((root->osc_control_set & ctrl) == ctrl)
+		goto out;
+
+	/* Need to check the available controls bits before requesting them. */
+	while (*mask) {
+		status = acpi_pci_query_osc(root, root->osc_support_set, mask);
+		if (ACPI_FAILURE(status))
+			goto out;
+		if (ctrl == *mask)
+			break;
+		decode_osc_control(root, "platform does not support",
+				   ctrl & ~(*mask));
+		ctrl = *mask;
+	}
+
+	if ((ctrl & req) != req) {
+		decode_osc_control(root, "not requesting control; platform does not support",
+				   req & ~(ctrl));
+		status = AE_SUPPORT;
+		goto out;
+	}
+
+	capbuf[OSC_QUERY_DWORD] = 0;
+	capbuf[OSC_SUPPORT_DWORD] = root->osc_support_set;
+	capbuf[OSC_CONTROL_DWORD] = ctrl;
+	status = acpi_pci_run_osc(handle, capbuf, mask);
+	if (ACPI_SUCCESS(status))
+		root->osc_control_set = *mask;
+out:
+	mutex_unlock(&osc_lock);
+	return status;
+}
+EXPORT_SYMBOL(acpi_pci_osc_control_set);
+
+static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm)
+{
+	u32 support, control, requested;
+	acpi_status status;
+	struct acpi_device *device = root->device;
+	acpi_handle handle = device->handle;
+
+	/*
+	 * Apple always return failure on _OSC calls when _OSI("Darwin") has
+	 * been called successfully. We know the feature set supported by the
+	 * platform, so avoid calling _OSC at all
+	 */
+	if (x86_apple_machine) {
+		root->osc_control_set = ~OSC_PCI_EXPRESS_PME_CONTROL;
+		decode_osc_control(root, "OS assumes control of",
+				   root->osc_control_set);
+		return;
+	}
+
+	/*
+	 * All supported architectures that use ACPI have support for
+	 * PCI domains, so we indicate this in _OSC support capabilities.
+	 */
+	support = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
+	if (pci_ext_cfg_avail())
+		support |= OSC_PCI_EXT_CONFIG_SUPPORT;
+	if (pcie_aspm_support_enabled())
+		support |= OSC_PCI_ASPM_SUPPORT | OSC_PCI_CLOCK_PM_SUPPORT;
+	if (pci_msi_enabled())
+		support |= OSC_PCI_MSI_SUPPORT;
+
+	decode_osc_support(root, "OS supports", support);
+	status = acpi_pci_osc_support(root, support);
+	if (ACPI_FAILURE(status)) {
+		dev_info(&device->dev, "_OSC failed (%s)%s\n",
+			 acpi_format_exception(status),
+			 pcie_aspm_support_enabled() ? "; disabling ASPM" : "");
+		*no_aspm = 1;
+		return;
+	}
+
+	if (pcie_ports_disabled) {
+		dev_info(&device->dev, "PCIe port services disabled; not requesting _OSC control\n");
+		return;
+	}
+
+	if ((support & ACPI_PCIE_REQ_SUPPORT) != ACPI_PCIE_REQ_SUPPORT) {
+		decode_osc_support(root, "not requesting OS control; OS requires",
+				   ACPI_PCIE_REQ_SUPPORT);
+		return;
+	}
+
+	control = OSC_PCI_EXPRESS_CAPABILITY_CONTROL
+		| OSC_PCI_EXPRESS_PME_CONTROL;
+
+	if (IS_ENABLED(CONFIG_PCIEASPM))
+		control |= OSC_PCI_EXPRESS_LTR_CONTROL;
+
+	if (IS_ENABLED(CONFIG_HOTPLUG_PCI_PCIE))
+		control |= OSC_PCI_EXPRESS_NATIVE_HP_CONTROL;
+
+	if (IS_ENABLED(CONFIG_HOTPLUG_PCI_SHPC))
+		control |= OSC_PCI_SHPC_NATIVE_HP_CONTROL;
+
+	if (pci_aer_available()) {
+		if (aer_acpi_firmware_first())
+			dev_info(&device->dev,
+				 "PCIe AER handled by firmware\n");
+		else
+			control |= OSC_PCI_EXPRESS_AER_CONTROL;
+	}
+
+	requested = control;
+	status = acpi_pci_osc_control_set(handle, &control,
+					  OSC_PCI_EXPRESS_CAPABILITY_CONTROL);
+	if (ACPI_SUCCESS(status)) {
+		decode_osc_control(root, "OS now controls", control);
+		if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
+			/*
+			 * We have ASPM control, but the FADT indicates that
+			 * it's unsupported. Leave existing configuration
+			 * intact and prevent the OS from touching it.
+			 */
+			dev_info(&device->dev, "FADT indicates ASPM is unsupported, using BIOS configuration\n");
+			*no_aspm = 1;
+		}
+	} else {
+		decode_osc_control(root, "OS requested", requested);
+		decode_osc_control(root, "platform willing to grant", control);
+		dev_info(&device->dev, "_OSC failed (%s); disabling ASPM\n",
+			acpi_format_exception(status));
+
+		/*
+		 * We want to disable ASPM here, but aspm_disabled
+		 * needs to remain in its state from boot so that we
+		 * properly handle PCIe 1.1 devices.  So we set this
+		 * flag here, to defer the action until after the ACPI
+		 * root scan.
+		 */
+		*no_aspm = 1;
+	}
+}
+
+static int acpi_pci_root_add(struct acpi_device *device,
+			     const struct acpi_device_id *not_used)
+{
+	unsigned long long segment, bus;
+	acpi_status status;
+	int result;
+	struct acpi_pci_root *root;
+	acpi_handle handle = device->handle;
+	int no_aspm = 0;
+	bool hotadd = system_state == SYSTEM_RUNNING;
+
+	root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
+	if (!root)
+		return -ENOMEM;
+
+	segment = 0;
+	status = acpi_evaluate_integer(handle, METHOD_NAME__SEG, NULL,
+				       &segment);
+	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
+		dev_err(&device->dev,  "can't evaluate _SEG\n");
+		result = -ENODEV;
+		goto end;
+	}
+
+	/* Check _CRS first, then _BBN.  If no _BBN, default to zero. */
+	root->secondary.flags = IORESOURCE_BUS;
+	status = try_get_root_bridge_busnr(handle, &root->secondary);
+	if (ACPI_FAILURE(status)) {
+		/*
+		 * We need both the start and end of the downstream bus range
+		 * to interpret _CBA (MMCONFIG base address), so it really is
+		 * supposed to be in _CRS.  If we don't find it there, all we
+		 * can do is assume [_BBN-0xFF] or [0-0xFF].
+		 */
+		root->secondary.end = 0xFF;
+		dev_warn(&device->dev,
+			 FW_BUG "no secondary bus range in _CRS\n");
+		status = acpi_evaluate_integer(handle, METHOD_NAME__BBN,
+					       NULL, &bus);
+		if (ACPI_SUCCESS(status))
+			root->secondary.start = bus;
+		else if (status == AE_NOT_FOUND)
+			root->secondary.start = 0;
+		else {
+			dev_err(&device->dev, "can't evaluate _BBN\n");
+			result = -ENODEV;
+			goto end;
+		}
+	}
+
+	root->device = device;
+	root->segment = segment & 0xFFFF;
+	strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
+	strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
+	device->driver_data = root;
+
+	if (hotadd && dmar_device_add(handle)) {
+		result = -ENXIO;
+		goto end;
+	}
+
+	pr_info(PREFIX "%s [%s] (domain %04x %pR)\n",
+	       acpi_device_name(device), acpi_device_bid(device),
+	       root->segment, &root->secondary);
+
+	root->mcfg_addr = acpi_pci_root_get_mcfg_addr(handle);
+
+	negotiate_os_control(root, &no_aspm);
+
+	/*
+	 * TBD: Need PCI interface for enumeration/configuration of roots.
+	 */
+
+	/*
+	 * Scan the Root Bridge
+	 * --------------------
+	 * Must do this prior to any attempt to bind the root device, as the
+	 * PCI namespace does not get created until this call is made (and
+	 * thus the root bridge's pci_dev does not exist).
+	 */
+	root->bus = pci_acpi_scan_root(root);
+	if (!root->bus) {
+		dev_err(&device->dev,
+			"Bus %04x:%02x not present in PCI namespace\n",
+			root->segment, (unsigned int)root->secondary.start);
+		device->driver_data = NULL;
+		result = -ENODEV;
+		goto remove_dmar;
+	}
+
+	if (no_aspm)
+		pcie_no_aspm();
+
+	pci_acpi_add_bus_pm_notifier(device);
+	device_set_wakeup_capable(root->bus->bridge, device->wakeup.flags.valid);
+
+	if (hotadd) {
+		pcibios_resource_survey_bus(root->bus);
+		pci_assign_unassigned_root_bus_resources(root->bus);
+		/*
+		 * This is only called for the hotadd case. For the boot-time
+		 * case, we need to wait until after PCI initialization in
+		 * order to deal with IOAPICs mapped in on a PCI BAR.
+		 *
+		 * This is currently x86-specific, because acpi_ioapic_add()
+		 * is an empty function without CONFIG_ACPI_HOTPLUG_IOAPIC.
+		 * And CONFIG_ACPI_HOTPLUG_IOAPIC depends on CONFIG_X86_IO_APIC
+		 * (see drivers/acpi/Kconfig).
+		 */
+		acpi_ioapic_add(root->device->handle);
+	}
+
+	pci_lock_rescan_remove();
+	pci_bus_add_devices(root->bus);
+	pci_unlock_rescan_remove();
+	return 1;
+
+remove_dmar:
+	if (hotadd)
+		dmar_device_remove(handle);
+end:
+	kfree(root);
+	return result;
+}
+
+static void acpi_pci_root_remove(struct acpi_device *device)
+{
+	struct acpi_pci_root *root = acpi_driver_data(device);
+
+	pci_lock_rescan_remove();
+
+	pci_stop_root_bus(root->bus);
+
+	pci_ioapic_remove(root);
+	device_set_wakeup_capable(root->bus->bridge, false);
+	pci_acpi_remove_bus_pm_notifier(device);
+
+	pci_remove_root_bus(root->bus);
+	WARN_ON(acpi_ioapic_remove(root));
+
+	dmar_device_remove(device->handle);
+
+	pci_unlock_rescan_remove();
+
+	kfree(root);
+}
+
+/*
+ * Following code to support acpi_pci_root_create() is copied from
+ * arch/x86/pci/acpi.c and modified so it could be reused by x86, IA64
+ * and ARM64.
+ */
+static void acpi_pci_root_validate_resources(struct device *dev,
+					     struct list_head *resources,
+					     unsigned long type)
+{
+	LIST_HEAD(list);
+	struct resource *res1, *res2, *root = NULL;
+	struct resource_entry *tmp, *entry, *entry2;
+
+	BUG_ON((type & (IORESOURCE_MEM | IORESOURCE_IO)) == 0);
+	root = (type & IORESOURCE_MEM) ? &iomem_resource : &ioport_resource;
+
+	list_splice_init(resources, &list);
+	resource_list_for_each_entry_safe(entry, tmp, &list) {
+		bool free = false;
+		resource_size_t end;
+
+		res1 = entry->res;
+		if (!(res1->flags & type))
+			goto next;
+
+		/* Exclude non-addressable range or non-addressable portion */
+		end = min(res1->end, root->end);
+		if (end <= res1->start) {
+			dev_info(dev, "host bridge window %pR (ignored, not CPU addressable)\n",
+				 res1);
+			free = true;
+			goto next;
+		} else if (res1->end != end) {
+			dev_info(dev, "host bridge window %pR ([%#llx-%#llx] ignored, not CPU addressable)\n",
+				 res1, (unsigned long long)end + 1,
+				 (unsigned long long)res1->end);
+			res1->end = end;
+		}
+
+		resource_list_for_each_entry(entry2, resources) {
+			res2 = entry2->res;
+			if (!(res2->flags & type))
+				continue;
+
+			/*
+			 * I don't like throwing away windows because then
+			 * our resources no longer match the ACPI _CRS, but
+			 * the kernel resource tree doesn't allow overlaps.
+			 */
+			if (resource_overlaps(res1, res2)) {
+				res2->start = min(res1->start, res2->start);
+				res2->end = max(res1->end, res2->end);
+				dev_info(dev, "host bridge window expanded to %pR; %pR ignored\n",
+					 res2, res1);
+				free = true;
+				goto next;
+			}
+		}
+
+next:
+		resource_list_del(entry);
+		if (free)
+			resource_list_free_entry(entry);
+		else
+			resource_list_add_tail(entry, resources);
+	}
+}
+
+static void acpi_pci_root_remap_iospace(struct fwnode_handle *fwnode,
+			struct resource_entry *entry)
+{
+#ifdef PCI_IOBASE
+	struct resource *res = entry->res;
+	resource_size_t cpu_addr = res->start;
+	resource_size_t pci_addr = cpu_addr - entry->offset;
+	resource_size_t length = resource_size(res);
+	unsigned long port;
+
+	if (pci_register_io_range(fwnode, cpu_addr, length))
+		goto err;
+
+	port = pci_address_to_pio(cpu_addr);
+	if (port == (unsigned long)-1)
+		goto err;
+
+	res->start = port;
+	res->end = port + length - 1;
+	entry->offset = port - pci_addr;
+
+	if (pci_remap_iospace(res, cpu_addr) < 0)
+		goto err;
+
+	pr_info("Remapped I/O %pa to %pR\n", &cpu_addr, res);
+	return;
+err:
+	res->flags |= IORESOURCE_DISABLED;
+#endif
+}
+
+int acpi_pci_probe_root_resources(struct acpi_pci_root_info *info)
+{
+	int ret;
+	struct list_head *list = &info->resources;
+	struct acpi_device *device = info->bridge;
+	struct resource_entry *entry, *tmp;
+	unsigned long flags;
+
+	flags = IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_MEM_8AND16BIT;
+	ret = acpi_dev_get_resources(device, list,
+				     acpi_dev_filter_resource_type_cb,
+				     (void *)flags);
+	if (ret < 0)
+		dev_warn(&device->dev,
+			 "failed to parse _CRS method, error code %d\n", ret);
+	else if (ret == 0)
+		dev_dbg(&device->dev,
+			"no IO and memory resources present in _CRS\n");
+	else {
+		resource_list_for_each_entry_safe(entry, tmp, list) {
+			if (entry->res->flags & IORESOURCE_IO)
+				acpi_pci_root_remap_iospace(&device->fwnode,
+						entry);
+
+			if (entry->res->flags & IORESOURCE_DISABLED)
+				resource_list_destroy_entry(entry);
+			else
+				entry->res->name = info->name;
+		}
+		acpi_pci_root_validate_resources(&device->dev, list,
+						 IORESOURCE_MEM);
+		acpi_pci_root_validate_resources(&device->dev, list,
+						 IORESOURCE_IO);
+	}
+
+	return ret;
+}
+
+static void pci_acpi_root_add_resources(struct acpi_pci_root_info *info)
+{
+	struct resource_entry *entry, *tmp;
+	struct resource *res, *conflict, *root = NULL;
+
+	resource_list_for_each_entry_safe(entry, tmp, &info->resources) {
+		res = entry->res;
+		if (res->flags & IORESOURCE_MEM)
+			root = &iomem_resource;
+		else if (res->flags & IORESOURCE_IO)
+			root = &ioport_resource;
+		else
+			continue;
+
+		/*
+		 * Some legacy x86 host bridge drivers use iomem_resource and
+		 * ioport_resource as default resource pool, skip it.
+		 */
+		if (res == root)
+			continue;
+
+		conflict = insert_resource_conflict(root, res);
+		if (conflict) {
+			dev_info(&info->bridge->dev,
+				 "ignoring host bridge window %pR (conflicts with %s %pR)\n",
+				 res, conflict->name, conflict);
+			resource_list_destroy_entry(entry);
+		}
+	}
+}
+
+static void __acpi_pci_root_release_info(struct acpi_pci_root_info *info)
+{
+	struct resource *res;
+	struct resource_entry *entry, *tmp;
+
+	if (!info)
+		return;
+
+	resource_list_for_each_entry_safe(entry, tmp, &info->resources) {
+		res = entry->res;
+		if (res->parent &&
+		    (res->flags & (IORESOURCE_MEM | IORESOURCE_IO)))
+			release_resource(res);
+		resource_list_destroy_entry(entry);
+	}
+
+	info->ops->release_info(info);
+}
+
+static void acpi_pci_root_release_info(struct pci_host_bridge *bridge)
+{
+	struct resource *res;
+	struct resource_entry *entry;
+
+	resource_list_for_each_entry(entry, &bridge->windows) {
+		res = entry->res;
+		if (res->flags & IORESOURCE_IO)
+			pci_unmap_iospace(res);
+		if (res->parent &&
+		    (res->flags & (IORESOURCE_MEM | IORESOURCE_IO)))
+			release_resource(res);
+	}
+	__acpi_pci_root_release_info(bridge->release_data);
+}
+
+struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root,
+				     struct acpi_pci_root_ops *ops,
+				     struct acpi_pci_root_info *info,
+				     void *sysdata)
+{
+	int ret, busnum = root->secondary.start;
+	struct acpi_device *device = root->device;
+	int node = acpi_get_node(device->handle);
+	struct pci_bus *bus;
+	struct pci_host_bridge *host_bridge;
+
+	info->root = root;
+	info->bridge = device;
+	info->ops = ops;
+	INIT_LIST_HEAD(&info->resources);
+	snprintf(info->name, sizeof(info->name), "PCI Bus %04x:%02x",
+		 root->segment, busnum);
+
+	if (ops->init_info && ops->init_info(info))
+		goto out_release_info;
+	if (ops->prepare_resources)
+		ret = ops->prepare_resources(info);
+	else
+		ret = acpi_pci_probe_root_resources(info);
+	if (ret < 0)
+		goto out_release_info;
+
+	pci_acpi_root_add_resources(info);
+	pci_add_resource(&info->resources, &root->secondary);
+	bus = pci_create_root_bus(NULL, busnum, ops->pci_ops,
+				  sysdata, &info->resources);
+	if (!bus)
+		goto out_release_info;
+
+	host_bridge = to_pci_host_bridge(bus->bridge);
+	if (!(root->osc_control_set & OSC_PCI_EXPRESS_NATIVE_HP_CONTROL))
+		host_bridge->native_pcie_hotplug = 0;
+	if (!(root->osc_control_set & OSC_PCI_SHPC_NATIVE_HP_CONTROL))
+		host_bridge->native_shpc_hotplug = 0;
+	if (!(root->osc_control_set & OSC_PCI_EXPRESS_AER_CONTROL))
+		host_bridge->native_aer = 0;
+	if (!(root->osc_control_set & OSC_PCI_EXPRESS_PME_CONTROL))
+		host_bridge->native_pme = 0;
+	if (!(root->osc_control_set & OSC_PCI_EXPRESS_LTR_CONTROL))
+		host_bridge->native_ltr = 0;
+
+	pci_scan_child_bus(bus);
+	pci_set_host_bridge_release(host_bridge, acpi_pci_root_release_info,
+				    info);
+	if (node != NUMA_NO_NODE)
+		dev_printk(KERN_DEBUG, &bus->dev, "on NUMA node %d\n", node);
+	return bus;
+
+out_release_info:
+	__acpi_pci_root_release_info(info);
+	return NULL;
+}
+
+void __init acpi_pci_root_init(void)
+{
+	acpi_hest_init();
+	if (acpi_pci_disabled)
+		return;
+
+	pci_acpi_crs_quirks();
+	acpi_scan_add_handler_with_hotplug(&pci_root_handler, "pci_root");
+}