// SPDX-License-Identifier: GPL-2.0+
/*
* ACPI PCI HotPlug glue functions to ACPI CA subsystem
*
* Copyright (C) 2002,2003 Takayoshi Kochi (t-kochi@bq.jp.nec.com)
* Copyright (C) 2002 Hiroshi Aono (h-aono@ap.jp.nec.com)
* Copyright (C) 2002,2003 NEC Corporation
* Copyright (C) 2003-2005 Matthew Wilcox (matthew.wilcox@hp.com)
* Copyright (C) 2003-2005 Hewlett Packard
* Copyright (C) 2005 Rajesh Shah (rajesh.shah@intel.com)
* Copyright (C) 2005 Intel Corporation
*
* All rights reserved.
*
* Send feedback to <kristen.c.accardi@intel.com>
*
*/
/*
* Lifetime rules for pci_dev:
* - The one in acpiphp_bridge has its refcount elevated by pci_get_slot()
* when the bridge is scanned and it loses a refcount when the bridge
* is removed.
* - When a P2P bridge is present, we elevate the refcount on the subordinate
* bus. It loses the refcount when the the driver unloads.
*/
#define pr_fmt(fmt) "acpiphp_glue: " fmt
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/pci_hotplug.h>
#include <linux/pci-acpi.h>
#include <linux/pm_runtime.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/acpi.h>
#include "../pci.h"
#include "acpiphp.h"
static LIST_HEAD(bridge_list);
static DEFINE_MUTEX(bridge_mutex);
static int acpiphp_hotplug_notify(struct acpi_device *adev, u32 type);
static void acpiphp_post_dock_fixup(struct acpi_device *adev);
static void acpiphp_sanitize_bus(struct pci_bus *bus);
static void hotplug_event(u32 type, struct acpiphp_context *context);
static void free_bridge(struct kref *kref);
/**
* acpiphp_init_context - Create hotplug context and grab a reference to it.
* @adev: ACPI device object to create the context for.
*
* Call under acpi_hp_context_lock.
*/
static struct acpiphp_context *acpiphp_init_context(struct acpi_device *adev)
{
struct acpiphp_context *context;
context = kzalloc(sizeof(*context), GFP_KERNEL);
if (!context)
return NULL;
context->refcount = 1;
context->hp.notify = acpiphp_hotplug_notify;
context->hp.fixup = acpiphp_post_dock_fixup;
acpi_set_hp_context(adev, &context->hp);
return context;
}
/**
* acpiphp_get_context - Get hotplug context and grab a reference to it.
* @adev: ACPI device object to get the context for.
*
* Call under acpi_hp_context_lock.
*/
static struct acpiphp_context *acpiphp_get_context(struct acpi_device *adev)
{
struct acpiphp_context *context;
if (!adev->hp)
return NULL;
context = to_acpiphp_context(adev->hp);
context->refcount++;
return context;
}
/**
* acpiphp_put_context - Drop a reference to ACPI hotplug context.
* @context: ACPI hotplug context to drop a reference to.
*
* The context object is removed if there are no more references to it.
*
* Call under acpi_hp_context_lock.
*/
static void acpiphp_put_context(struct acpiphp_context *context)
{
if (--context->refcount)
return;
WARN_ON(context->bridge);
context->hp.self->hp = NULL;
kfree(context);
}
static inline void get_bridge(struct acpiphp_bridge *bridge)
{
kref_get(&bridge->ref);
}
static inline void put_bridge(struct acpiphp_bridge *bridge)
{
kref_put(&bridge->ref, free_bridge);
}
static struct acpiphp_context *acpiphp_grab_context(struct acpi_device *adev)
{
struct acpiphp_context *context;
acpi_lock_hp_context();
context = acpiphp_get_context(adev);
if (!context || context->func.parent->is_going_away) {
acpi_unlock_hp_context();
return NULL;
}
get_bridge(context->func.parent);
acpiphp_put_context(context);
acpi_unlock_hp_context();
return context;
}
static void acpiphp_let_context_go(struct acpiphp_context *context)
{
put_bridge(context->func.parent);
}
static void free_bridge(struct kref *kref)
{
struct acpiphp_context *context;
struct acpiphp_bridge *bridge;
struct acpiphp_slot *slot, *next;
struct acpiphp_func *func, *tmp;
acpi_lock_hp_context();
bridge = container_of(kref, struct acpiphp_bridge, ref);
list_for_each_entry_safe(slot, next, &bridge->slots, node) {
list_for_each_entry_safe(func, tmp, &slot->funcs, sibling)
acpiphp_put_context(func_to_context(func));
kfree(slot);
}
context = bridge->context;
/* Root bridges will not have hotplug context. */
if (context) {
/* Release the reference taken by acpiphp_enumerate_slots(). */
put_bridge(context->func.parent);
context->bridge = NULL;