![Matthew Garrett](/assets/img/avatar_default.png)
The PCI SIG documentation for the _OSC OS/firmware handshaking interface states: "If the _OSC control method is absent from the scope of a host bridge device, then the operating system must not enable or attempt to use any features defined in this section for the hierarchy originated by the host bridge." The obvious interpretation of this is that the OS should not attempt to use PCIe hotplug, PME or AER - however, the specification also notes that an _OSC method is *required* for PCIe hierarchies, and experimental validation with An Alternative OS indicates that it doesn't use any PCIe functionality if the _OSC method is missing. That arguably means we shouldn't be using MSI or extended config space, but right now our problems seem to be limited to vendors being surprised when ASPM gets enabled on machines when other OSs refuse to do so. So, for now, let's just disable ASPM if the _OSC method doesn't exist or refuses to hand over PCIe capability control. Acked-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Matthew Garrett <mjg@redhat.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
600 lines
15 KiB
C
600 lines
15 KiB
C
/*
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* pci_root.c - ACPI PCI Root Bridge Driver ($Revision: 40 $)
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*
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* Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
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* Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
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*
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* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or (at
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* your option) any later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
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*
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* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/types.h>
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#include <linux/proc_fs.h>
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#include <linux/spinlock.h>
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#include <linux/pm.h>
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#include <linux/pm_runtime.h>
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#include <linux/pci.h>
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#include <linux/pci-acpi.h>
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#include <linux/pci-aspm.h>
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#include <linux/acpi.h>
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#include <linux/slab.h>
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#include <acpi/acpi_bus.h>
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#include <acpi/acpi_drivers.h>
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#define PREFIX "ACPI: "
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#define _COMPONENT ACPI_PCI_COMPONENT
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ACPI_MODULE_NAME("pci_root");
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#define ACPI_PCI_ROOT_CLASS "pci_bridge"
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#define ACPI_PCI_ROOT_DEVICE_NAME "PCI Root Bridge"
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static int acpi_pci_root_add(struct acpi_device *device);
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static int acpi_pci_root_remove(struct acpi_device *device, int type);
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static int acpi_pci_root_start(struct acpi_device *device);
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static const struct acpi_device_id root_device_ids[] = {
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{"PNP0A03", 0},
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{"", 0},
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};
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MODULE_DEVICE_TABLE(acpi, root_device_ids);
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static struct acpi_driver acpi_pci_root_driver = {
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.name = "pci_root",
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.class = ACPI_PCI_ROOT_CLASS,
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.ids = root_device_ids,
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.ops = {
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.add = acpi_pci_root_add,
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.remove = acpi_pci_root_remove,
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.start = acpi_pci_root_start,
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},
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};
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static LIST_HEAD(acpi_pci_roots);
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static struct acpi_pci_driver *sub_driver;
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static DEFINE_MUTEX(osc_lock);
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int acpi_pci_register_driver(struct acpi_pci_driver *driver)
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{
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int n = 0;
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struct acpi_pci_root *root;
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struct acpi_pci_driver **pptr = &sub_driver;
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while (*pptr)
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pptr = &(*pptr)->next;
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*pptr = driver;
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if (!driver->add)
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return 0;
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list_for_each_entry(root, &acpi_pci_roots, node) {
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driver->add(root->device->handle);
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n++;
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}
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return n;
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}
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EXPORT_SYMBOL(acpi_pci_register_driver);
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void acpi_pci_unregister_driver(struct acpi_pci_driver *driver)
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{
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struct acpi_pci_root *root;
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struct acpi_pci_driver **pptr = &sub_driver;
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while (*pptr) {
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if (*pptr == driver)
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break;
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pptr = &(*pptr)->next;
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}
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BUG_ON(!*pptr);
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*pptr = (*pptr)->next;
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if (!driver->remove)
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return;
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list_for_each_entry(root, &acpi_pci_roots, node)
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driver->remove(root->device->handle);
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}
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EXPORT_SYMBOL(acpi_pci_unregister_driver);
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acpi_handle acpi_get_pci_rootbridge_handle(unsigned int seg, unsigned int bus)
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{
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struct acpi_pci_root *root;
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list_for_each_entry(root, &acpi_pci_roots, node)
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if ((root->segment == (u16) seg) &&
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(root->secondary.start == (u16) bus))
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return root->device->handle;
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return NULL;
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}
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EXPORT_SYMBOL_GPL(acpi_get_pci_rootbridge_handle);
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/**
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* acpi_is_root_bridge - determine whether an ACPI CA node is a PCI root bridge
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* @handle - the ACPI CA node in question.
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*
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* Note: we could make this API take a struct acpi_device * instead, but
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* for now, it's more convenient to operate on an acpi_handle.
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*/
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int acpi_is_root_bridge(acpi_handle handle)
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{
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int ret;
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struct acpi_device *device;
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ret = acpi_bus_get_device(handle, &device);
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if (ret)
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return 0;
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ret = acpi_match_device_ids(device, root_device_ids);
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if (ret)
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return 0;
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else
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return 1;
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}
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EXPORT_SYMBOL_GPL(acpi_is_root_bridge);
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static acpi_status
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get_root_bridge_busnr_callback(struct acpi_resource *resource, void *data)
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{
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struct resource *res = data;
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struct acpi_resource_address64 address;
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if (resource->type != ACPI_RESOURCE_TYPE_ADDRESS16 &&
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resource->type != ACPI_RESOURCE_TYPE_ADDRESS32 &&
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resource->type != ACPI_RESOURCE_TYPE_ADDRESS64)
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return AE_OK;
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acpi_resource_to_address64(resource, &address);
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if ((address.address_length > 0) &&
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(address.resource_type == ACPI_BUS_NUMBER_RANGE)) {
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res->start = address.minimum;
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res->end = address.minimum + address.address_length - 1;
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}
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return AE_OK;
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}
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static acpi_status try_get_root_bridge_busnr(acpi_handle handle,
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struct resource *res)
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{
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acpi_status status;
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res->start = -1;
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status =
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acpi_walk_resources(handle, METHOD_NAME__CRS,
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get_root_bridge_busnr_callback, res);
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if (ACPI_FAILURE(status))
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return status;
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if (res->start == -1)
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return AE_ERROR;
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return AE_OK;
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}
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static void acpi_pci_bridge_scan(struct acpi_device *device)
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{
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int status;
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struct acpi_device *child = NULL;
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if (device->flags.bus_address)
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if (device->parent && device->parent->ops.bind) {
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status = device->parent->ops.bind(device);
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if (!status) {
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list_for_each_entry(child, &device->children, node)
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acpi_pci_bridge_scan(child);
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}
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}
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}
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static u8 pci_osc_uuid_str[] = "33DB4D5B-1FF7-401C-9657-7441C03DD766";
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static acpi_status acpi_pci_run_osc(acpi_handle handle,
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const u32 *capbuf, u32 *retval)
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{
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struct acpi_osc_context context = {
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.uuid_str = pci_osc_uuid_str,
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.rev = 1,
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.cap.length = 12,
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.cap.pointer = (void *)capbuf,
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};
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acpi_status status;
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status = acpi_run_osc(handle, &context);
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if (ACPI_SUCCESS(status)) {
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*retval = *((u32 *)(context.ret.pointer + 8));
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kfree(context.ret.pointer);
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}
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return status;
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}
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static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root, u32 flags)
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{
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acpi_status status;
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u32 support_set, result, capbuf[3];
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/* do _OSC query for all possible controls */
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support_set = root->osc_support_set | (flags & OSC_PCI_SUPPORT_MASKS);
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capbuf[OSC_QUERY_TYPE] = OSC_QUERY_ENABLE;
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capbuf[OSC_SUPPORT_TYPE] = support_set;
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capbuf[OSC_CONTROL_TYPE] = OSC_PCI_CONTROL_MASKS;
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status = acpi_pci_run_osc(root->device->handle, capbuf, &result);
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if (ACPI_SUCCESS(status)) {
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root->osc_support_set = support_set;
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root->osc_control_qry = result;
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root->osc_queried = 1;
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}
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return status;
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}
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static acpi_status acpi_pci_osc_support(struct acpi_pci_root *root, u32 flags)
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{
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acpi_status status;
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acpi_handle tmp;
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status = acpi_get_handle(root->device->handle, "_OSC", &tmp);
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if (ACPI_FAILURE(status))
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return status;
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mutex_lock(&osc_lock);
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status = acpi_pci_query_osc(root, flags);
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mutex_unlock(&osc_lock);
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return status;
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}
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struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle)
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{
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struct acpi_pci_root *root;
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list_for_each_entry(root, &acpi_pci_roots, node) {
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if (root->device->handle == handle)
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return root;
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}
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return NULL;
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}
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EXPORT_SYMBOL_GPL(acpi_pci_find_root);
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struct acpi_handle_node {
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struct list_head node;
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acpi_handle handle;
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};
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/**
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* acpi_get_pci_dev - convert ACPI CA handle to struct pci_dev
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* @handle: the handle in question
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*
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* Given an ACPI CA handle, the desired PCI device is located in the
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* list of PCI devices.
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*
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* If the device is found, its reference count is increased and this
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* function returns a pointer to its data structure. The caller must
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* decrement the reference count by calling pci_dev_put().
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* If no device is found, %NULL is returned.
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*/
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struct pci_dev *acpi_get_pci_dev(acpi_handle handle)
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{
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int dev, fn;
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unsigned long long adr;
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acpi_status status;
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acpi_handle phandle;
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struct pci_bus *pbus;
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struct pci_dev *pdev = NULL;
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struct acpi_handle_node *node, *tmp;
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struct acpi_pci_root *root;
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LIST_HEAD(device_list);
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/*
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* Walk up the ACPI CA namespace until we reach a PCI root bridge.
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*/
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phandle = handle;
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while (!acpi_is_root_bridge(phandle)) {
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node = kzalloc(sizeof(struct acpi_handle_node), GFP_KERNEL);
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if (!node)
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goto out;
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INIT_LIST_HEAD(&node->node);
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node->handle = phandle;
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list_add(&node->node, &device_list);
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status = acpi_get_parent(phandle, &phandle);
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if (ACPI_FAILURE(status))
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goto out;
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}
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root = acpi_pci_find_root(phandle);
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if (!root)
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goto out;
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pbus = root->bus;
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/*
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* Now, walk back down the PCI device tree until we return to our
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* original handle. Assumes that everything between the PCI root
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* bridge and the device we're looking for must be a P2P bridge.
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*/
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list_for_each_entry(node, &device_list, node) {
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acpi_handle hnd = node->handle;
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status = acpi_evaluate_integer(hnd, "_ADR", NULL, &adr);
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if (ACPI_FAILURE(status))
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goto out;
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dev = (adr >> 16) & 0xffff;
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fn = adr & 0xffff;
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pdev = pci_get_slot(pbus, PCI_DEVFN(dev, fn));
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if (!pdev || hnd == handle)
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break;
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pbus = pdev->subordinate;
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pci_dev_put(pdev);
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/*
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* This function may be called for a non-PCI device that has a
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* PCI parent (eg. a disk under a PCI SATA controller). In that
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* case pdev->subordinate will be NULL for the parent.
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*/
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if (!pbus) {
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dev_dbg(&pdev->dev, "Not a PCI-to-PCI bridge\n");
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pdev = NULL;
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break;
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}
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}
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out:
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list_for_each_entry_safe(node, tmp, &device_list, node)
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kfree(node);
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return pdev;
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}
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EXPORT_SYMBOL_GPL(acpi_get_pci_dev);
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/**
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* acpi_pci_osc_control_set - commit requested control to Firmware
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* @handle: acpi_handle for the target ACPI object
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* @flags: driver's requested control bits
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*
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* Attempt to take control from Firmware on requested control bits.
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**/
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acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 flags)
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{
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acpi_status status;
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u32 control_req, result, capbuf[3];
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acpi_handle tmp;
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struct acpi_pci_root *root;
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status = acpi_get_handle(handle, "_OSC", &tmp);
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if (ACPI_FAILURE(status))
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return status;
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control_req = (flags & OSC_PCI_CONTROL_MASKS);
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if (!control_req)
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return AE_TYPE;
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root = acpi_pci_find_root(handle);
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if (!root)
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return AE_NOT_EXIST;
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mutex_lock(&osc_lock);
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/* No need to evaluate _OSC if the control was already granted. */
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if ((root->osc_control_set & control_req) == control_req)
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goto out;
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/* Need to query controls first before requesting them */
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if (!root->osc_queried) {
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status = acpi_pci_query_osc(root, root->osc_support_set);
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if (ACPI_FAILURE(status))
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goto out;
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}
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if ((root->osc_control_qry & control_req) != control_req) {
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printk(KERN_DEBUG
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"Firmware did not grant requested _OSC control\n");
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status = AE_SUPPORT;
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goto out;
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}
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capbuf[OSC_QUERY_TYPE] = 0;
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capbuf[OSC_SUPPORT_TYPE] = root->osc_support_set;
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capbuf[OSC_CONTROL_TYPE] = root->osc_control_set | control_req;
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status = acpi_pci_run_osc(handle, capbuf, &result);
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if (ACPI_SUCCESS(status))
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root->osc_control_set = result;
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out:
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mutex_unlock(&osc_lock);
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return status;
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}
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EXPORT_SYMBOL(acpi_pci_osc_control_set);
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static int __devinit acpi_pci_root_add(struct acpi_device *device)
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{
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unsigned long long segment, bus;
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acpi_status status;
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int result;
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struct acpi_pci_root *root;
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acpi_handle handle;
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struct acpi_device *child;
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u32 flags, base_flags;
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root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
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if (!root)
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return -ENOMEM;
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segment = 0;
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status = acpi_evaluate_integer(device->handle, METHOD_NAME__SEG, NULL,
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&segment);
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if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
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printk(KERN_ERR PREFIX "can't evaluate _SEG\n");
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result = -ENODEV;
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goto end;
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}
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/* Check _CRS first, then _BBN. If no _BBN, default to zero. */
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root->secondary.flags = IORESOURCE_BUS;
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status = try_get_root_bridge_busnr(device->handle, &root->secondary);
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if (ACPI_FAILURE(status)) {
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/*
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* We need both the start and end of the downstream bus range
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* to interpret _CBA (MMCONFIG base address), so it really is
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* supposed to be in _CRS. If we don't find it there, all we
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* can do is assume [_BBN-0xFF] or [0-0xFF].
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*/
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root->secondary.end = 0xFF;
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printk(KERN_WARNING FW_BUG PREFIX
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"no secondary bus range in _CRS\n");
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status = acpi_evaluate_integer(device->handle, METHOD_NAME__BBN, NULL, &bus);
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if (ACPI_SUCCESS(status))
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root->secondary.start = bus;
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else if (status == AE_NOT_FOUND)
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root->secondary.start = 0;
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else {
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printk(KERN_ERR PREFIX "can't evaluate _BBN\n");
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result = -ENODEV;
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goto end;
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}
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}
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INIT_LIST_HEAD(&root->node);
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root->device = device;
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root->segment = segment & 0xFFFF;
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strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
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strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
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device->driver_data = root;
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/*
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* All supported architectures that use ACPI have support for
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* PCI domains, so we indicate this in _OSC support capabilities.
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*/
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flags = base_flags = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
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acpi_pci_osc_support(root, flags);
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/*
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* TBD: Need PCI interface for enumeration/configuration of roots.
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*/
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/* TBD: Locking */
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list_add_tail(&root->node, &acpi_pci_roots);
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printk(KERN_INFO PREFIX "%s [%s] (domain %04x %pR)\n",
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acpi_device_name(device), acpi_device_bid(device),
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root->segment, &root->secondary);
|
|
|
|
/*
|
|
* 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) {
|
|
printk(KERN_ERR PREFIX
|
|
"Bus %04x:%02x not present in PCI namespace\n",
|
|
root->segment, (unsigned int)root->secondary.start);
|
|
result = -ENODEV;
|
|
goto end;
|
|
}
|
|
|
|
/*
|
|
* Attach ACPI-PCI Context
|
|
* -----------------------
|
|
* Thus binding the ACPI and PCI devices.
|
|
*/
|
|
result = acpi_pci_bind_root(device);
|
|
if (result)
|
|
goto end;
|
|
|
|
/*
|
|
* PCI Routing Table
|
|
* -----------------
|
|
* Evaluate and parse _PRT, if exists.
|
|
*/
|
|
status = acpi_get_handle(device->handle, METHOD_NAME__PRT, &handle);
|
|
if (ACPI_SUCCESS(status))
|
|
result = acpi_pci_irq_add_prt(device->handle, root->bus);
|
|
|
|
/*
|
|
* Scan and bind all _ADR-Based Devices
|
|
*/
|
|
list_for_each_entry(child, &device->children, node)
|
|
acpi_pci_bridge_scan(child);
|
|
|
|
/* Indicate support for various _OSC capabilities. */
|
|
if (pci_ext_cfg_avail(root->bus->self))
|
|
flags |= OSC_EXT_PCI_CONFIG_SUPPORT;
|
|
if (pcie_aspm_enabled())
|
|
flags |= OSC_ACTIVE_STATE_PWR_SUPPORT |
|
|
OSC_CLOCK_PWR_CAPABILITY_SUPPORT;
|
|
if (pci_msi_enabled())
|
|
flags |= OSC_MSI_SUPPORT;
|
|
if (flags != base_flags)
|
|
acpi_pci_osc_support(root, flags);
|
|
|
|
status = acpi_pci_osc_control_set(root->device->handle,
|
|
OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL);
|
|
|
|
if (ACPI_FAILURE(status)) {
|
|
printk(KERN_INFO "Unable to assume PCIe control: Disabling ASPM\n");
|
|
pcie_no_aspm();
|
|
}
|
|
|
|
pci_acpi_add_bus_pm_notifier(device, root->bus);
|
|
if (device->wakeup.flags.run_wake)
|
|
device_set_run_wake(root->bus->bridge, true);
|
|
|
|
return 0;
|
|
|
|
end:
|
|
if (!list_empty(&root->node))
|
|
list_del(&root->node);
|
|
kfree(root);
|
|
return result;
|
|
}
|
|
|
|
static int acpi_pci_root_start(struct acpi_device *device)
|
|
{
|
|
struct acpi_pci_root *root = acpi_driver_data(device);
|
|
|
|
pci_bus_add_devices(root->bus);
|
|
return 0;
|
|
}
|
|
|
|
static int acpi_pci_root_remove(struct acpi_device *device, int type)
|
|
{
|
|
struct acpi_pci_root *root = acpi_driver_data(device);
|
|
|
|
device_set_run_wake(root->bus->bridge, false);
|
|
pci_acpi_remove_bus_pm_notifier(device);
|
|
|
|
kfree(root);
|
|
return 0;
|
|
}
|
|
|
|
static int __init acpi_pci_root_init(void)
|
|
{
|
|
if (acpi_pci_disabled)
|
|
return 0;
|
|
|
|
pci_acpi_crs_quirks();
|
|
if (acpi_bus_register_driver(&acpi_pci_root_driver) < 0)
|
|
return -ENODEV;
|
|
|
|
return 0;
|
|
}
|
|
|
|
subsys_initcall(acpi_pci_root_init);
|