linux/drivers/pci/slot.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2006 Matthew Wilcox <[email protected]>
 * Copyright (C) 2006-2009 Hewlett-Packard Development Company, L.P.
 *	Alex Chiang <[email protected]>
 */

#include <linux/kobject.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/err.h>
#include "pci.h"

struct kset *pci_slots_kset;
EXPORT_SYMBOL_GPL(…);

static ssize_t pci_slot_attr_show(struct kobject *kobj,
					struct attribute *attr, char *buf)
{ … }

static ssize_t pci_slot_attr_store(struct kobject *kobj,
			struct attribute *attr, const char *buf, size_t len)
{ … }

static const struct sysfs_ops pci_slot_sysfs_ops = …;

static ssize_t address_read_file(struct pci_slot *slot, char *buf)
{ … }

static ssize_t bus_speed_read(enum pci_bus_speed speed, char *buf)
{ … }

static ssize_t max_speed_read_file(struct pci_slot *slot, char *buf)
{ … }

static ssize_t cur_speed_read_file(struct pci_slot *slot, char *buf)
{ … }

static void pci_slot_release(struct kobject *kobj)
{ … }

static struct pci_slot_attribute pci_slot_attr_address = …;
static struct pci_slot_attribute pci_slot_attr_max_speed = …;
static struct pci_slot_attribute pci_slot_attr_cur_speed = …;

static struct attribute *pci_slot_default_attrs[] = …;
ATTRIBUTE_GROUPS(…);

static const struct kobj_type pci_slot_ktype = …;

static char *make_slot_name(const char *name)
{ … }

static int rename_slot(struct pci_slot *slot, const char *name)
{ … }

void pci_dev_assign_slot(struct pci_dev *dev)
{ … }

static struct pci_slot *get_slot(struct pci_bus *parent, int slot_nr)
{ … }

/**
 * pci_create_slot - create or increment refcount for physical PCI slot
 * @parent: struct pci_bus of parent bridge
 * @slot_nr: PCI_SLOT(pci_dev->devfn) or -1 for placeholder
 * @name: user visible string presented in /sys/bus/pci/slots/<name>
 * @hotplug: set if caller is hotplug driver, NULL otherwise
 *
 * PCI slots have first class attributes such as address, speed, width,
 * and a &struct pci_slot is used to manage them. This interface will
 * either return a new &struct pci_slot to the caller, or if the pci_slot
 * already exists, its refcount will be incremented.
 *
 * Slots are uniquely identified by a @pci_bus, @slot_nr tuple.
 *
 * There are known platforms with broken firmware that assign the same
 * name to multiple slots. Workaround these broken platforms by renaming
 * the slots on behalf of the caller. If firmware assigns name N to
 * multiple slots:
 *
 * The first slot is assigned N
 * The second slot is assigned N-1
 * The third slot is assigned N-2
 * etc.
 *
 * Placeholder slots:
 * In most cases, @pci_bus, @slot_nr will be sufficient to uniquely identify
 * a slot. There is one notable exception - pSeries (rpaphp), where the
 * @slot_nr cannot be determined until a device is actually inserted into
 * the slot. In this scenario, the caller may pass -1 for @slot_nr.
 *
 * The following semantics are imposed when the caller passes @slot_nr ==
 * -1. First, we no longer check for an existing %struct pci_slot, as there
 * may be many slots with @slot_nr of -1.  The other change in semantics is
 * user-visible, which is the 'address' parameter presented in sysfs will
 * consist solely of a dddd:bb tuple, where dddd is the PCI domain of the
 * %struct pci_bus and bb is the bus number. In other words, the devfn of
 * the 'placeholder' slot will not be displayed.
 */
struct pci_slot *pci_create_slot(struct pci_bus *parent, int slot_nr,
				 const char *name,
				 struct hotplug_slot *hotplug)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * pci_destroy_slot - decrement refcount for physical PCI slot
 * @slot: struct pci_slot to decrement
 *
 * %struct pci_slot is refcounted, so destroying them is really easy; we
 * just call kobject_put on its kobj and let our release methods do the
 * rest.
 */
void pci_destroy_slot(struct pci_slot *slot)
{ … }
EXPORT_SYMBOL_GPL(…);

#if defined(CONFIG_HOTPLUG_PCI) || defined(CONFIG_HOTPLUG_PCI_MODULE)
#include <linux/pci_hotplug.h>
/**
 * pci_hp_create_module_link - create symbolic link to hotplug driver module
 * @pci_slot: struct pci_slot
 *
 * Helper function for pci_hotplug_core.c to create symbolic link to
 * the hotplug driver module.
 */
void pci_hp_create_module_link(struct pci_slot *pci_slot)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * pci_hp_remove_module_link - remove symbolic link to the hotplug driver
 * 	module.
 * @pci_slot: struct pci_slot
 *
 * Helper function for pci_hotplug_core.c to remove symbolic link to
 * the hotplug driver module.
 */
void pci_hp_remove_module_link(struct pci_slot *pci_slot)
{ … }
EXPORT_SYMBOL_GPL(…);
#endif

static int pci_slot_init(void)
{ … }

subsys_initcall(pci_slot_init);