228 lines
6.5 KiB
C
228 lines
6.5 KiB
C
/*
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* Common ACPI functions for hot plug platforms
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*
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* Copyright (C) 2006 Intel Corporation
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*
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* All rights reserved.
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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, GOOD TITLE or
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* NON INFRINGEMENT. See the GNU General Public License for more
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* details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*
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* Send feedback to <kristen.c.accardi@intel.com>
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*
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*/
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/kernel.h>
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#include <linux/types.h>
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#include <linux/pci.h>
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#include <linux/pci_hotplug.h>
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#include <linux/acpi.h>
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#include <linux/pci-acpi.h>
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#include <linux/slab.h>
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#define MY_NAME "acpi_pcihp"
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#define dbg(fmt, arg...) do { if (debug_acpi) printk(KERN_DEBUG "%s: %s: " fmt, MY_NAME, __func__, ## arg); } while (0)
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#define err(format, arg...) printk(KERN_ERR "%s: " format, MY_NAME, ## arg)
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#define info(format, arg...) printk(KERN_INFO "%s: " format, MY_NAME, ## arg)
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#define warn(format, arg...) printk(KERN_WARNING "%s: " format, MY_NAME, ## arg)
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#define METHOD_NAME__SUN "_SUN"
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#define METHOD_NAME_OSHP "OSHP"
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static bool debug_acpi;
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/* acpi_run_oshp - get control of hotplug from the firmware
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*
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* @handle - the handle of the hotplug controller.
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*/
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static acpi_status acpi_run_oshp(acpi_handle handle)
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{
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acpi_status status;
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struct acpi_buffer string = { ACPI_ALLOCATE_BUFFER, NULL };
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acpi_get_name(handle, ACPI_FULL_PATHNAME, &string);
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/* run OSHP */
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status = acpi_evaluate_object(handle, METHOD_NAME_OSHP, NULL, NULL);
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if (ACPI_FAILURE(status))
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if (status != AE_NOT_FOUND)
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printk(KERN_ERR "%s:%s OSHP fails=0x%x\n",
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__func__, (char *)string.pointer, status);
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else
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dbg("%s:%s OSHP not found\n",
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__func__, (char *)string.pointer);
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else
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pr_debug("%s:%s OSHP passes\n", __func__,
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(char *)string.pointer);
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kfree(string.pointer);
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return status;
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}
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/**
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* acpi_get_hp_hw_control_from_firmware
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* @dev: the pci_dev of the bridge that has a hotplug controller
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* @flags: requested control bits for _OSC
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*
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* Attempt to take hotplug control from firmware.
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*/
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int acpi_get_hp_hw_control_from_firmware(struct pci_dev *pdev, u32 flags)
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{
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acpi_status status;
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acpi_handle chandle, handle;
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struct acpi_buffer string = { ACPI_ALLOCATE_BUFFER, NULL };
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flags &= OSC_PCI_SHPC_NATIVE_HP_CONTROL;
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if (!flags) {
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err("Invalid flags %u specified!\n", flags);
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return -EINVAL;
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}
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/*
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* Per PCI firmware specification, we should run the ACPI _OSC
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* method to get control of hotplug hardware before using it. If
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* an _OSC is missing, we look for an OSHP to do the same thing.
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* To handle different BIOS behavior, we look for _OSC on a root
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* bridge preferentially (according to PCI fw spec). Later for
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* OSHP within the scope of the hotplug controller and its parents,
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* up to the host bridge under which this controller exists.
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*/
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handle = acpi_find_root_bridge_handle(pdev);
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if (handle) {
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acpi_get_name(handle, ACPI_FULL_PATHNAME, &string);
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dbg("Trying to get hotplug control for %s\n",
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(char *)string.pointer);
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status = acpi_pci_osc_control_set(handle, &flags, flags);
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if (ACPI_SUCCESS(status))
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goto got_one;
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if (status == AE_SUPPORT)
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goto no_control;
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kfree(string.pointer);
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string = (struct acpi_buffer){ ACPI_ALLOCATE_BUFFER, NULL };
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}
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handle = ACPI_HANDLE(&pdev->dev);
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if (!handle) {
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/*
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* This hotplug controller was not listed in the ACPI name
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* space at all. Try to get acpi handle of parent pci bus.
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*/
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struct pci_bus *pbus;
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for (pbus = pdev->bus; pbus; pbus = pbus->parent) {
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handle = acpi_pci_get_bridge_handle(pbus);
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if (handle)
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break;
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}
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}
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while (handle) {
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acpi_get_name(handle, ACPI_FULL_PATHNAME, &string);
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dbg("Trying to get hotplug control for %s\n",
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(char *)string.pointer);
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status = acpi_run_oshp(handle);
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if (ACPI_SUCCESS(status))
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goto got_one;
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if (acpi_is_root_bridge(handle))
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break;
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chandle = handle;
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status = acpi_get_parent(chandle, &handle);
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if (ACPI_FAILURE(status))
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break;
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}
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no_control:
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dbg("Cannot get control of hotplug hardware for pci %s\n",
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pci_name(pdev));
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kfree(string.pointer);
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return -ENODEV;
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got_one:
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dbg("Gained control for hotplug HW for pci %s (%s)\n",
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pci_name(pdev), (char *)string.pointer);
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kfree(string.pointer);
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return 0;
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}
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EXPORT_SYMBOL(acpi_get_hp_hw_control_from_firmware);
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static int pcihp_is_ejectable(acpi_handle handle)
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{
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acpi_status status;
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unsigned long long removable;
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if (!acpi_has_method(handle, "_ADR"))
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return 0;
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if (acpi_has_method(handle, "_EJ0"))
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return 1;
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status = acpi_evaluate_integer(handle, "_RMV", NULL, &removable);
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if (ACPI_SUCCESS(status) && removable)
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return 1;
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return 0;
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}
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/**
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* acpi_pcihp_check_ejectable - check if handle is ejectable ACPI PCI slot
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* @pbus: the PCI bus of the PCI slot corresponding to 'handle'
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* @handle: ACPI handle to check
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*
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* Return 1 if handle is ejectable PCI slot, 0 otherwise.
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*/
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int acpi_pci_check_ejectable(struct pci_bus *pbus, acpi_handle handle)
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{
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acpi_handle bridge_handle, parent_handle;
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bridge_handle = acpi_pci_get_bridge_handle(pbus);
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if (!bridge_handle)
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return 0;
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if ((ACPI_FAILURE(acpi_get_parent(handle, &parent_handle))))
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return 0;
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if (bridge_handle != parent_handle)
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return 0;
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return pcihp_is_ejectable(handle);
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}
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EXPORT_SYMBOL_GPL(acpi_pci_check_ejectable);
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static acpi_status
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check_hotplug(acpi_handle handle, u32 lvl, void *context, void **rv)
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{
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int *found = (int *)context;
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if (pcihp_is_ejectable(handle)) {
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*found = 1;
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return AE_CTRL_TERMINATE;
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}
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return AE_OK;
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}
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/**
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* acpi_pci_detect_ejectable - check if the PCI bus has ejectable slots
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* @handle - handle of the PCI bus to scan
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*
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* Returns 1 if the PCI bus has ACPI based ejectable slots, 0 otherwise.
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*/
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int acpi_pci_detect_ejectable(acpi_handle handle)
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{
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int found = 0;
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if (!handle)
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return found;
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acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
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check_hotplug, NULL, (void *)&found, NULL);
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return found;
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}
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EXPORT_SYMBOL_GPL(acpi_pci_detect_ejectable);
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module_param(debug_acpi, bool, 0644);
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MODULE_PARM_DESC(debug_acpi, "Debugging mode for ACPI enabled or not");
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