Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2006 Matthew Wilcox <matthew@wil.cx>
 * Copyright (C) 2006-2009 Hewlett-Packard Development Company, L.P.
 *	Alex Chiang <achiang@hp.com>
 */
 
#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(pci_slots_kset);
 
static ssize_t pci_slot_attr_show(struct kobject *kobj,
<------><------><------><------><------>struct attribute *attr, char *buf)
{
<------>struct pci_slot *slot = to_pci_slot(kobj);
<------>struct pci_slot_attribute *attribute = to_pci_slot_attr(attr);
<------>return attribute->show ? attribute->show(slot, buf) : -EIO;
}
 
static ssize_t pci_slot_attr_store(struct kobject *kobj,
<------><------><------>struct attribute *attr, const char *buf, size_t len)
{
<------>struct pci_slot *slot = to_pci_slot(kobj);
<------>struct pci_slot_attribute *attribute = to_pci_slot_attr(attr);
<------>return attribute->store ? attribute->store(slot, buf, len) : -EIO;
}
 
static const struct sysfs_ops pci_slot_sysfs_ops = {
<------>.show = pci_slot_attr_show,
<------>.store = pci_slot_attr_store,
};
 
static ssize_t address_read_file(struct pci_slot *slot, char *buf)
{
<------>if (slot->number == 0xff)
<------><------>return sprintf(buf, "%04x:%02x\n",
<------><------><------><------>pci_domain_nr(slot->bus),
<------><------><------><------>slot->bus->number);
<------>else
<------><------>return sprintf(buf, "%04x:%02x:%02x\n",
<------><------><------><------>pci_domain_nr(slot->bus),
<------><------><------><------>slot->bus->number,
<------><------><------><------>slot->number);
}
 
static ssize_t bus_speed_read(enum pci_bus_speed speed, char *buf)
{
<------>return sprintf(buf, "%s\n", pci_speed_string(speed));
}
 
static ssize_t max_speed_read_file(struct pci_slot *slot, char *buf)
{
<------>return bus_speed_read(slot->bus->max_bus_speed, buf);
}
 
static ssize_t cur_speed_read_file(struct pci_slot *slot, char *buf)
{
<------>return bus_speed_read(slot->bus->cur_bus_speed, buf);
}
 
static void pci_slot_release(struct kobject *kobj)
{
<------>struct pci_dev *dev;
<------>struct pci_slot *slot = to_pci_slot(kobj);
 
<------>dev_dbg(&slot->bus->dev, "dev %02x, released physical slot %s\n",
<------><------>slot->number, pci_slot_name(slot));
 
<------>down_read(&pci_bus_sem);
<------>list_for_each_entry(dev, &slot->bus->devices, bus_list)
<------><------>if (PCI_SLOT(dev->devfn) == slot->number)
<------><------><------>dev->slot = NULL;
<------>up_read(&pci_bus_sem);
 
<------>list_del(&slot->list);
 
<------>kfree(slot);
}
 
static struct pci_slot_attribute pci_slot_attr_address =
<------>__ATTR(address, S_IRUGO, address_read_file, NULL);
static struct pci_slot_attribute pci_slot_attr_max_speed =
<------>__ATTR(max_bus_speed, S_IRUGO, max_speed_read_file, NULL);
static struct pci_slot_attribute pci_slot_attr_cur_speed =
<------>__ATTR(cur_bus_speed, S_IRUGO, cur_speed_read_file, NULL);
 
static struct attribute *pci_slot_default_attrs[] = {
<------>&pci_slot_attr_address.attr,
<------>&pci_slot_attr_max_speed.attr,
<------>&pci_slot_attr_cur_speed.attr,
<------>NULL,
};
 
static struct kobj_type pci_slot_ktype = {
<------>.sysfs_ops = &pci_slot_sysfs_ops,
<------>.release = &pci_slot_release,
<------>.default_attrs = pci_slot_default_attrs,
};
 
static char *make_slot_name(const char *name)
{
<------>char *new_name;
<------>int len, max, dup;
 
<------>new_name = kstrdup(name, GFP_KERNEL);
<------>if (!new_name)
<------><------>return NULL;
 
<------>/*
<------> * Make sure we hit the realloc case the first time through the
<------> * loop.  'len' will be strlen(name) + 3 at that point which is
<------> * enough space for "name-X" and the trailing NUL.
<------> */
<------>len = strlen(name) + 2;
<------>max = 1;
<------>dup = 1;
 
<------>for (;;) {
<------><------>struct kobject *dup_slot;
<------><------>dup_slot = kset_find_obj(pci_slots_kset, new_name);
<------><------>if (!dup_slot)
<------><------><------>break;
<------><------>kobject_put(dup_slot);
<------><------>if (dup == max) {
<------><------><------>len++;
<------><------><------>max *= 10;
<------><------><------>kfree(new_name);
<------><------><------>new_name = kmalloc(len, GFP_KERNEL);
<------><------><------>if (!new_name)
<------><------><------><------>break;
<------><------>}
<------><------>sprintf(new_name, "%s-%d", name, dup++);
<------>}
 
<------>return new_name;
}
 
static int rename_slot(struct pci_slot *slot, const char *name)
{
<------>int result = 0;
<------>char *slot_name;
 
<------>if (strcmp(pci_slot_name(slot), name) == 0)
<------><------>return result;
 
<------>slot_name = make_slot_name(name);
<------>if (!slot_name)
<------><------>return -ENOMEM;
 
<------>result = kobject_rename(&slot->kobj, slot_name);
<------>kfree(slot_name);
 
<------>return result;
}
 
void pci_dev_assign_slot(struct pci_dev *dev)
{
<------>struct pci_slot *slot;
 
<------>mutex_lock(&pci_slot_mutex);
<------>list_for_each_entry(slot, &dev->bus->slots, list)
<------><------>if (PCI_SLOT(dev->devfn) == slot->number)
<------><------><------>dev->slot = slot;
<------>mutex_unlock(&pci_slot_mutex);
}
 
static struct pci_slot *get_slot(struct pci_bus *parent, int slot_nr)
{
<------>struct pci_slot *slot;
 
<------>/* We already hold pci_slot_mutex */
<------>list_for_each_entry(slot, &parent->slots, list)
<------><------>if (slot->number == slot_nr) {
<------><------><------>kobject_get(&slot->kobj);
<------><------><------>return slot;
<------><------>}
 
<------>return NULL;
}
 
/**
 * 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)
{
<------>struct pci_dev *dev;
<------>struct pci_slot *slot;
<------>int err = 0;
<------>char *slot_name = NULL;
 
<------>mutex_lock(&pci_slot_mutex);
 
<------>if (slot_nr == -1)
<------><------>goto placeholder;
 
<------>/*
<------> * Hotplug drivers are allowed to rename an existing slot,
<------> * but only if not already claimed.
<------> */
<------>slot = get_slot(parent, slot_nr);
<------>if (slot) {
<------><------>if (hotplug) {
<------><------><------>if ((err = slot->hotplug ? -EBUSY : 0)
<------><------><------>     || (err = rename_slot(slot, name))) {
<------><------><------><------>kobject_put(&slot->kobj);
<------><------><------><------>slot = NULL;
<------><------><------><------>goto err;
<------><------><------>}
<------><------>}
<------><------>goto out;
<------>}
 
placeholder:
<------>slot = kzalloc(sizeof(*slot), GFP_KERNEL);
<------>if (!slot) {
<------><------>err = -ENOMEM;
<------><------>goto err;
<------>}
 
<------>slot->bus = parent;
<------>slot->number = slot_nr;
 
<------>slot->kobj.kset = pci_slots_kset;
 
<------>slot_name = make_slot_name(name);
<------>if (!slot_name) {
<------><------>err = -ENOMEM;
<------><------>kfree(slot);
<------><------>goto err;
<------>}
 
<------>INIT_LIST_HEAD(&slot->list);
<------>list_add(&slot->list, &parent->slots);
 
<------>err = kobject_init_and_add(&slot->kobj, &pci_slot_ktype, NULL,
<------><------><------><------>   "%s", slot_name);
<------>if (err) {
<------><------>kobject_put(&slot->kobj);
<------><------>goto err;
<------>}
 
<------>down_read(&pci_bus_sem);
<------>list_for_each_entry(dev, &parent->devices, bus_list)
<------><------>if (PCI_SLOT(dev->devfn) == slot_nr)
<------><------><------>dev->slot = slot;
<------>up_read(&pci_bus_sem);
 
<------>dev_dbg(&parent->dev, "dev %02x, created physical slot %s\n",
<------><------>slot_nr, pci_slot_name(slot));
 
out:
<------>kfree(slot_name);
<------>mutex_unlock(&pci_slot_mutex);
<------>return slot;
err:
<------>slot = ERR_PTR(err);
<------>goto out;
}
EXPORT_SYMBOL_GPL(pci_create_slot);
 
/**
 * 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)
{
<------>dev_dbg(&slot->bus->dev, "dev %02x, dec refcount to %d\n",
<------><------>slot->number, kref_read(&slot->kobj.kref) - 1);
 
<------>mutex_lock(&pci_slot_mutex);
<------>kobject_put(&slot->kobj);
<------>mutex_unlock(&pci_slot_mutex);
}
EXPORT_SYMBOL_GPL(pci_destroy_slot);
 
#if defined(CONFIG_HOTPLUG_PCI) || defined(CONFIG_HOTPLUG_PCI_MODULE)
#include <linux/pci_hotplug.h>
/**
 * pci_hp_create_link - create symbolic link to the 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)
{
<------>struct hotplug_slot *slot = pci_slot->hotplug;
<------>struct kobject *kobj = NULL;
<------>int ret;
 
<------>if (!slot || !slot->ops)
<------><------>return;
<------>kobj = kset_find_obj(module_kset, slot->mod_name);
<------>if (!kobj)
<------><------>return;
<------>ret = sysfs_create_link(&pci_slot->kobj, kobj, "module");
<------>if (ret)
<------><------>dev_err(&pci_slot->bus->dev, "Error creating sysfs link (%d)\n",
<------><------><------>ret);
<------>kobject_put(kobj);
}
EXPORT_SYMBOL_GPL(pci_hp_create_module_link);
 
/**
 * pci_hp_remove_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)
{
<------>sysfs_remove_link(&pci_slot->kobj, "module");
}
EXPORT_SYMBOL_GPL(pci_hp_remove_module_link);
#endif
 
static int pci_slot_init(void)
{
<------>struct kset *pci_bus_kset;
 
<------>pci_bus_kset = bus_get_kset(&pci_bus_type);
<------>pci_slots_kset = kset_create_and_add("slots", NULL,
<------><------><------><------><------><------>&pci_bus_kset->kobj);
<------>if (!pci_slots_kset) {
<------><------>pr_err("PCI: Slot initialization failure\n");
<------><------>return -ENOMEM;
<------>}
<------>return 0;
}
 
subsys_initcall(pci_slot_init);