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![Krzysztof Wilczyński](/assets/img/avatar_default.png)
Fix kernel-doc formatting errors, function names that don't match the doc, and some missing parameter documentation. These are reported by: make W=1 drivers/pci/ No functional change intended. [bhelgaas: squashed into one patch since this only changes comments] Link: https://lore.kernel.org/r/20210311001724.423356-1-kw@linux.com Link: https://lore.kernel.org/r/20210311001724.423356-2-kw@linux.com Link: https://lore.kernel.org/r/20210311001724.423356-3-kw@linux.com Link: https://lore.kernel.org/r/20210311001724.423356-4-kw@linux.com Link: https://lore.kernel.org/r/20210311001724.423356-5-kw@linux.com Link: https://lore.kernel.org/r/20210311001724.423356-6-kw@linux.com Link: https://lore.kernel.org/r/20210311001724.423356-7-kw@linux.com Link: https://lore.kernel.org/r/20210311001724.423356-8-kw@linux.com Signed-off-by: Krzysztof Wilczyński <kw@linux.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
212 lines
5.7 KiB
C
212 lines
5.7 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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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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* Send feedback to <kristen.c.accardi@intel.com>
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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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* @pdev: the pci_dev of the bridge that has a hotplug controller
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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)
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{
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const struct pci_host_bridge *host;
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const struct acpi_pci_root *root;
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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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/*
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* If there's no ACPI host bridge (i.e., ACPI support is compiled
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* into the kernel but the hardware platform doesn't support ACPI),
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* there's nothing to do here.
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*/
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host = pci_find_host_bridge(pdev->bus);
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root = acpi_pci_find_root(ACPI_HANDLE(&host->dev));
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if (!root)
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return 0;
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/*
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* If _OSC exists, it determines whether we're allowed to manage
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* the SHPC. We executed it while enumerating the host bridge.
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*/
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if (root->osc_support_set) {
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if (host->native_shpc_hotplug)
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return 0;
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return -ENODEV;
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}
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/*
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* In the absence of _OSC, we're always allowed to manage the SHPC.
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* However, if an OSHP method is present, we must execute it so the
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* firmware can transfer control to the OS, e.g., direct interrupts
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* to the OS instead of to the firmware.
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*
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* N.B. The PCI Firmware Spec (r3.2, sec 4.8) does not endorse
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* searching up the ACPI hierarchy, so the loops below are suspect.
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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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pci_info(pdev, "Requesting control of SHPC hotplug via OSHP (%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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pci_info(pdev, "Cannot get control of SHPC hotplug\n");
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kfree(string.pointer);
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return -ENODEV;
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got_one:
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pci_info(pdev, "Gained control of SHPC hotplug (%s)\n",
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(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_pci_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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