diff options
Diffstat (limited to 'drivers/pci/slot.c')
| -rw-r--r-- | drivers/pci/slot.c | 414 |
1 files changed, 414 insertions, 0 deletions
diff --git a/drivers/pci/slot.c b/drivers/pci/slot.c new file mode 100644 index 000000000..dfbe9cbf2 --- /dev/null +++ b/drivers/pci/slot.c @@ -0,0 +1,414 @@ +// 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); +} + +/* these strings match up with the values in pci_bus_speed */ +static const char *pci_bus_speed_strings[] = { + "33 MHz PCI", /* 0x00 */ + "66 MHz PCI", /* 0x01 */ + "66 MHz PCI-X", /* 0x02 */ + "100 MHz PCI-X", /* 0x03 */ + "133 MHz PCI-X", /* 0x04 */ + NULL, /* 0x05 */ + NULL, /* 0x06 */ + NULL, /* 0x07 */ + NULL, /* 0x08 */ + "66 MHz PCI-X 266", /* 0x09 */ + "100 MHz PCI-X 266", /* 0x0a */ + "133 MHz PCI-X 266", /* 0x0b */ + "Unknown AGP", /* 0x0c */ + "1x AGP", /* 0x0d */ + "2x AGP", /* 0x0e */ + "4x AGP", /* 0x0f */ + "8x AGP", /* 0x10 */ + "66 MHz PCI-X 533", /* 0x11 */ + "100 MHz PCI-X 533", /* 0x12 */ + "133 MHz PCI-X 533", /* 0x13 */ + "2.5 GT/s PCIe", /* 0x14 */ + "5.0 GT/s PCIe", /* 0x15 */ + "8.0 GT/s PCIe", /* 0x16 */ + "16.0 GT/s PCIe", /* 0x17 */ +}; + +static ssize_t bus_speed_read(enum pci_bus_speed speed, char *buf) +{ + const char *speed_string; + + if (speed < ARRAY_SIZE(pci_bus_speed_strings)) + speed_string = pci_bus_speed_strings[speed]; + else + speed_string = "Unknown"; + + return sprintf(buf, "%s\n", speed_string); +} + +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->ops->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) { + printk(KERN_ERR "PCI: Slot initialization failure\n"); + return -ENOMEM; + } + return 0; +} + +subsys_initcall(pci_slot_init); |