9217a98467
Multiple race conditions are possible between the ACPI-based PCI hotplug (ACPIPHP) and the generic PCI bus rescan and device removal that can be triggered via sysfs. To avoid those race conditions make the ACPIPHP code use global PCI rescan-remove locking. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
359 lines
10 KiB
C
359 lines
10 KiB
C
/*
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* ACPI PCI Hot Plug Controller Driver
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*
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* Copyright (C) 1995,2001 Compaq Computer Corporation
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* Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
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* Copyright (C) 2001 IBM Corp.
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* Copyright (C) 2002 Hiroshi Aono (h-aono@ap.jp.nec.com)
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* Copyright (C) 2002,2003 Takayoshi Kochi (t-kochi@bq.jp.nec.com)
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* Copyright (C) 2002,2003 NEC Corporation
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* Copyright (C) 2003-2005 Matthew Wilcox (matthew.wilcox@hp.com)
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* Copyright (C) 2003-2005 Hewlett Packard
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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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#define pr_fmt(fmt) "acpiphp: " fmt
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#include <linux/init.h>
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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/pci.h>
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#include <linux/pci-acpi.h>
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#include <linux/pci_hotplug.h>
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#include <linux/slab.h>
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#include <linux/smp.h>
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#include "acpiphp.h"
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/* name size which is used for entries in pcihpfs */
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#define SLOT_NAME_SIZE 21 /* {_SUN} */
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bool acpiphp_disabled;
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/* local variables */
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static struct acpiphp_attention_info *attention_info;
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#define DRIVER_VERSION "0.5"
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#define DRIVER_AUTHOR "Greg Kroah-Hartman <gregkh@us.ibm.com>, Takayoshi Kochi <t-kochi@bq.jp.nec.com>, Matthew Wilcox <willy@hp.com>"
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#define DRIVER_DESC "ACPI Hot Plug PCI Controller Driver"
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MODULE_AUTHOR(DRIVER_AUTHOR);
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MODULE_DESCRIPTION(DRIVER_DESC);
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MODULE_LICENSE("GPL");
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MODULE_PARM_DESC(disable, "disable acpiphp driver");
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module_param_named(disable, acpiphp_disabled, bool, 0444);
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/* export the attention callback registration methods */
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EXPORT_SYMBOL_GPL(acpiphp_register_attention);
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EXPORT_SYMBOL_GPL(acpiphp_unregister_attention);
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static int enable_slot (struct hotplug_slot *slot);
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static int disable_slot (struct hotplug_slot *slot);
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static int set_attention_status (struct hotplug_slot *slot, u8 value);
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static int get_power_status (struct hotplug_slot *slot, u8 *value);
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static int get_attention_status (struct hotplug_slot *slot, u8 *value);
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static int get_latch_status (struct hotplug_slot *slot, u8 *value);
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static int get_adapter_status (struct hotplug_slot *slot, u8 *value);
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static struct hotplug_slot_ops acpi_hotplug_slot_ops = {
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.enable_slot = enable_slot,
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.disable_slot = disable_slot,
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.set_attention_status = set_attention_status,
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.get_power_status = get_power_status,
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.get_attention_status = get_attention_status,
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.get_latch_status = get_latch_status,
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.get_adapter_status = get_adapter_status,
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};
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/**
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* acpiphp_register_attention - set attention LED callback
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* @info: must be completely filled with LED callbacks
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*
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* Description: This is used to register a hardware specific ACPI
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* driver that manipulates the attention LED. All the fields in
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* info must be set.
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*/
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int acpiphp_register_attention(struct acpiphp_attention_info *info)
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{
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int retval = -EINVAL;
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if (info && info->owner && info->set_attn &&
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info->get_attn && !attention_info) {
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retval = 0;
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attention_info = info;
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}
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return retval;
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}
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/**
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* acpiphp_unregister_attention - unset attention LED callback
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* @info: must match the pointer used to register
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*
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* Description: This is used to un-register a hardware specific acpi
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* driver that manipulates the attention LED. The pointer to the
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* info struct must be the same as the one used to set it.
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*/
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int acpiphp_unregister_attention(struct acpiphp_attention_info *info)
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{
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int retval = -EINVAL;
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if (info && attention_info == info) {
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attention_info = NULL;
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retval = 0;
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}
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return retval;
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}
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/**
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* enable_slot - power on and enable a slot
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* @hotplug_slot: slot to enable
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*
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* Actual tasks are done in acpiphp_enable_slot()
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*/
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static int enable_slot(struct hotplug_slot *hotplug_slot)
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{
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struct slot *slot = hotplug_slot->private;
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pr_debug("%s - physical_slot = %s\n", __func__, slot_name(slot));
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/* enable the specified slot */
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return acpiphp_enable_slot(slot->acpi_slot);
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}
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/**
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* disable_slot - disable and power off a slot
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* @hotplug_slot: slot to disable
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*
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* Actual tasks are done in acpiphp_disable_slot()
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*/
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static int disable_slot(struct hotplug_slot *hotplug_slot)
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{
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struct slot *slot = hotplug_slot->private;
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pr_debug("%s - physical_slot = %s\n", __func__, slot_name(slot));
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/* disable the specified slot */
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return acpiphp_disable_slot(slot->acpi_slot);
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}
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/**
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* set_attention_status - set attention LED
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* @hotplug_slot: slot to set attention LED on
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* @status: value to set attention LED to (0 or 1)
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*
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* attention status LED, so we use a callback that
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* was registered with us. This allows hardware specific
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* ACPI implementations to blink the light for us.
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*/
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static int set_attention_status(struct hotplug_slot *hotplug_slot, u8 status)
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{
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int retval = -ENODEV;
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pr_debug("%s - physical_slot = %s\n", __func__,
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hotplug_slot_name(hotplug_slot));
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if (attention_info && try_module_get(attention_info->owner)) {
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retval = attention_info->set_attn(hotplug_slot, status);
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module_put(attention_info->owner);
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} else
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attention_info = NULL;
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return retval;
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}
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/**
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* get_power_status - get power status of a slot
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* @hotplug_slot: slot to get status
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* @value: pointer to store status
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*
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* Some platforms may not implement _STA method properly.
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* In that case, the value returned may not be reliable.
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*/
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static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
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{
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struct slot *slot = hotplug_slot->private;
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pr_debug("%s - physical_slot = %s\n", __func__, slot_name(slot));
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*value = acpiphp_get_power_status(slot->acpi_slot);
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return 0;
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}
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/**
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* get_attention_status - get attention LED status
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* @hotplug_slot: slot to get status from
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* @value: returns with value of attention LED
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*
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* ACPI doesn't have known method to determine the state
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* of the attention status LED, so we use a callback that
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* was registered with us. This allows hardware specific
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* ACPI implementations to determine its state.
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*/
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static int get_attention_status(struct hotplug_slot *hotplug_slot, u8 *value)
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{
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int retval = -EINVAL;
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pr_debug("%s - physical_slot = %s\n", __func__,
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hotplug_slot_name(hotplug_slot));
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if (attention_info && try_module_get(attention_info->owner)) {
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retval = attention_info->get_attn(hotplug_slot, value);
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module_put(attention_info->owner);
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} else
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attention_info = NULL;
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return retval;
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}
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/**
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* get_latch_status - get latch status of a slot
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* @hotplug_slot: slot to get status
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* @value: pointer to store status
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*
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* ACPI doesn't provide any formal means to access latch status.
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* Instead, we fake latch status from _STA.
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*/
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static int get_latch_status(struct hotplug_slot *hotplug_slot, u8 *value)
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{
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struct slot *slot = hotplug_slot->private;
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pr_debug("%s - physical_slot = %s\n", __func__, slot_name(slot));
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*value = acpiphp_get_latch_status(slot->acpi_slot);
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return 0;
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}
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/**
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* get_adapter_status - get adapter status of a slot
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* @hotplug_slot: slot to get status
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* @value: pointer to store status
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*
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* ACPI doesn't provide any formal means to access adapter status.
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* Instead, we fake adapter status from _STA.
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*/
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static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
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{
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struct slot *slot = hotplug_slot->private;
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pr_debug("%s - physical_slot = %s\n", __func__, slot_name(slot));
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*value = acpiphp_get_adapter_status(slot->acpi_slot);
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return 0;
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}
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/**
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* release_slot - free up the memory used by a slot
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* @hotplug_slot: slot to free
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*/
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static void release_slot(struct hotplug_slot *hotplug_slot)
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{
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struct slot *slot = hotplug_slot->private;
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pr_debug("%s - physical_slot = %s\n", __func__, slot_name(slot));
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kfree(slot->hotplug_slot);
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kfree(slot);
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}
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/* callback routine to initialize 'struct slot' for each slot */
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int acpiphp_register_hotplug_slot(struct acpiphp_slot *acpiphp_slot,
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unsigned int sun)
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{
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struct slot *slot;
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int retval = -ENOMEM;
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char name[SLOT_NAME_SIZE];
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slot = kzalloc(sizeof(*slot), GFP_KERNEL);
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if (!slot)
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goto error;
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slot->hotplug_slot = kzalloc(sizeof(*slot->hotplug_slot), GFP_KERNEL);
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if (!slot->hotplug_slot)
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goto error_slot;
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slot->hotplug_slot->info = &slot->info;
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slot->hotplug_slot->private = slot;
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slot->hotplug_slot->release = &release_slot;
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slot->hotplug_slot->ops = &acpi_hotplug_slot_ops;
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slot->acpi_slot = acpiphp_slot;
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slot->hotplug_slot->info->power_status = acpiphp_get_power_status(slot->acpi_slot);
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slot->hotplug_slot->info->attention_status = 0;
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slot->hotplug_slot->info->latch_status = acpiphp_get_latch_status(slot->acpi_slot);
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slot->hotplug_slot->info->adapter_status = acpiphp_get_adapter_status(slot->acpi_slot);
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acpiphp_slot->slot = slot;
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slot->sun = sun;
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snprintf(name, SLOT_NAME_SIZE, "%u", sun);
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retval = pci_hp_register(slot->hotplug_slot, acpiphp_slot->bus,
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acpiphp_slot->device, name);
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if (retval == -EBUSY)
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goto error_hpslot;
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if (retval) {
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pr_err("pci_hp_register failed with error %d\n", retval);
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goto error_hpslot;
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}
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pr_info("Slot [%s] registered\n", slot_name(slot));
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return 0;
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error_hpslot:
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kfree(slot->hotplug_slot);
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error_slot:
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kfree(slot);
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error:
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return retval;
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}
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void acpiphp_unregister_hotplug_slot(struct acpiphp_slot *acpiphp_slot)
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{
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struct slot *slot = acpiphp_slot->slot;
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int retval = 0;
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pr_info("Slot [%s] unregistered\n", slot_name(slot));
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retval = pci_hp_deregister(slot->hotplug_slot);
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if (retval)
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pr_err("pci_hp_deregister failed with error %d\n", retval);
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}
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void __init acpiphp_init(void)
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{
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pr_info(DRIVER_DESC " version: " DRIVER_VERSION "%s\n",
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acpiphp_disabled ? ", disabled by user; please report a bug"
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: "");
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}
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