357 lines
8.0 KiB
C
357 lines
8.0 KiB
C
/*
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* Fake PCI Hot Plug Controller Driver
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*
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* Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
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* Copyright (C) 2003 IBM Corp.
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* Copyright (C) 2003 Rolf Eike Beer <eike-kernel@sf-tec.de>
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*
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* Based on ideas and code from:
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* Vladimir Kondratiev <vladimir.kondratiev@intel.com>
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* Rolf Eike Beer <eike-kernel@sf-tec.de>
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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, version 2 of the License.
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*
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* Send feedback to <greg@kroah.com>
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*/
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/*
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*
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* This driver will "emulate" removing PCI devices from the system. If
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* the "power" file is written to with "0" then the specified PCI device
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* will be completely removed from the kernel.
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*
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* WARNING, this does NOT turn off the power to the PCI device. This is
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* a "logical" removal, not a physical or electrical removal.
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*
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* Use this module at your own risk, you have been warned!
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*
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* Enabling PCI devices is left as an exercise for the reader...
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*
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/pci.h>
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#include <linux/init.h>
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#include <linux/string.h>
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#include <linux/slab.h>
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#include "pci_hotplug.h"
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#include "../pci.h"
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#if !defined(MODULE)
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#define MY_NAME "fakephp"
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#else
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#define MY_NAME THIS_MODULE->name
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#endif
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#define dbg(format, arg...) \
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do { \
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if (debug) \
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printk(KERN_DEBUG "%s: " format, \
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MY_NAME , ## arg); \
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} while (0)
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#define err(format, arg...) printk(KERN_ERR "%s: " format, MY_NAME , ## arg)
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#define info(format, arg...) printk(KERN_INFO "%s: " format, MY_NAME , ## arg)
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#define DRIVER_AUTHOR "Greg Kroah-Hartman <greg@kroah.com>"
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#define DRIVER_DESC "Fake PCI Hot Plug Controller Driver"
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struct dummy_slot {
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struct list_head node;
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struct hotplug_slot *slot;
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struct pci_dev *dev;
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};
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static int debug;
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static LIST_HEAD(slot_list);
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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 struct hotplug_slot_ops dummy_hotplug_slot_ops = {
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.owner = THIS_MODULE,
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.enable_slot = enable_slot,
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.disable_slot = disable_slot,
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};
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static void dummy_release(struct hotplug_slot *slot)
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{
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struct dummy_slot *dslot = slot->private;
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list_del(&dslot->node);
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kfree(dslot->slot->info);
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kfree(dslot->slot);
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pci_dev_put(dslot->dev);
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kfree(dslot);
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}
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static int add_slot(struct pci_dev *dev)
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{
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struct dummy_slot *dslot;
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struct hotplug_slot *slot;
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int retval = -ENOMEM;
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slot = kzalloc(sizeof(struct hotplug_slot), GFP_KERNEL);
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if (!slot)
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goto error;
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slot->info = kzalloc(sizeof(struct hotplug_slot_info), GFP_KERNEL);
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if (!slot->info)
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goto error_slot;
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slot->info->power_status = 1;
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slot->info->max_bus_speed = PCI_SPEED_UNKNOWN;
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slot->info->cur_bus_speed = PCI_SPEED_UNKNOWN;
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slot->name = &dev->dev.bus_id[0];
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dbg("slot->name = %s\n", slot->name);
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dslot = kmalloc(sizeof(struct dummy_slot), GFP_KERNEL);
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if (!dslot)
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goto error_info;
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slot->ops = &dummy_hotplug_slot_ops;
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slot->release = &dummy_release;
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slot->private = dslot;
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retval = pci_hp_register(slot);
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if (retval) {
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err("pci_hp_register failed with error %d\n", retval);
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goto error_dslot;
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}
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dslot->slot = slot;
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dslot->dev = pci_dev_get(dev);
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list_add (&dslot->node, &slot_list);
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return retval;
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error_dslot:
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kfree(dslot);
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error_info:
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kfree(slot->info);
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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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static int __init pci_scan_buses(void)
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{
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struct pci_dev *dev = NULL;
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int retval = 0;
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while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
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retval = add_slot(dev);
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if (retval) {
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pci_dev_put(dev);
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break;
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}
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}
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return retval;
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}
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static void remove_slot(struct dummy_slot *dslot)
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{
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int retval;
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dbg("removing slot %s\n", dslot->slot->name);
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retval = pci_hp_deregister(dslot->slot);
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if (retval)
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err("Problem unregistering a slot %s\n", dslot->slot->name);
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}
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/**
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* Rescan slot.
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* Tries hard not to re-enable already existing devices
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* also handles scanning of subfunctions
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*
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* @param temp Device template. Should be set: bus and devfn.
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*/
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static void pci_rescan_slot(struct pci_dev *temp)
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{
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struct pci_bus *bus = temp->bus;
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struct pci_dev *dev;
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int func;
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u8 hdr_type;
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if (!pci_read_config_byte(temp, PCI_HEADER_TYPE, &hdr_type)) {
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temp->hdr_type = hdr_type & 0x7f;
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if (!pci_find_slot(bus->number, temp->devfn)) {
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dev = pci_scan_single_device(bus, temp->devfn);
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if (dev) {
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dbg("New device on %s function %x:%x\n",
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bus->name, temp->devfn >> 3,
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temp->devfn & 7);
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pci_bus_add_device(dev);
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add_slot(dev);
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}
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}
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/* multifunction device? */
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if (!(hdr_type & 0x80))
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return;
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/* continue scanning for other functions */
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for (func = 1, temp->devfn++; func < 8; func++, temp->devfn++) {
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if (pci_read_config_byte(temp, PCI_HEADER_TYPE, &hdr_type))
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continue;
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temp->hdr_type = hdr_type & 0x7f;
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if (!pci_find_slot(bus->number, temp->devfn)) {
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dev = pci_scan_single_device(bus, temp->devfn);
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if (dev) {
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dbg("New device on %s function %x:%x\n",
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bus->name, temp->devfn >> 3,
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temp->devfn & 7);
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pci_bus_add_device(dev);
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add_slot(dev);
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}
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}
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}
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}
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}
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/**
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* Rescan PCI bus.
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* call pci_rescan_slot for each possible function of the bus
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*
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* @param bus
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*/
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static void pci_rescan_bus(const struct pci_bus *bus)
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{
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unsigned int devfn;
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struct pci_dev *dev;
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dev = kzalloc(sizeof(struct pci_dev), GFP_KERNEL);
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if (!dev)
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return;
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dev->bus = (struct pci_bus*)bus;
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dev->sysdata = bus->sysdata;
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for (devfn = 0; devfn < 0x100; devfn += 8) {
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dev->devfn = devfn;
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pci_rescan_slot(dev);
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}
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kfree(dev);
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}
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/* recursively scan all buses */
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static void pci_rescan_buses(const struct list_head *list)
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{
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const struct list_head *l;
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list_for_each(l,list) {
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const struct pci_bus *b = pci_bus_b(l);
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pci_rescan_bus(b);
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pci_rescan_buses(&b->children);
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}
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}
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/* initiate rescan of all pci buses */
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static inline void pci_rescan(void) {
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pci_rescan_buses(&pci_root_buses);
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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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/* mis-use enable_slot for rescanning of the pci bus */
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pci_rescan();
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return -ENODEV;
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}
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/* find the hotplug_slot for the pci_dev */
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static struct hotplug_slot *get_slot_from_dev(struct pci_dev *dev)
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{
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struct dummy_slot *dslot;
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list_for_each_entry(dslot, &slot_list, node) {
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if (dslot->dev == dev)
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return dslot->slot;
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}
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return NULL;
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}
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static int disable_slot(struct hotplug_slot *slot)
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{
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struct dummy_slot *dslot;
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struct hotplug_slot *hslot;
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struct pci_dev *dev;
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int func;
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if (!slot)
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return -ENODEV;
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dslot = slot->private;
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dbg("%s - physical_slot = %s\n", __FUNCTION__, slot->name);
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/* don't disable bridged devices just yet, we can't handle them easily... */
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if (dslot->dev->subordinate) {
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err("Can't remove PCI devices with other PCI devices behind it yet.\n");
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return -ENODEV;
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}
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/* search for subfunctions and disable them first */
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if (!(dslot->dev->devfn & 7)) {
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for (func = 1; func < 8; func++) {
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dev = pci_find_slot(dslot->dev->bus->number,
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dslot->dev->devfn + func);
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if (dev) {
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hslot = get_slot_from_dev(dev);
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if (hslot)
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disable_slot(hslot);
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else {
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err("Hotplug slot not found for subfunction of PCI device\n");
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return -ENODEV;
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}
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} else
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dbg("No device in slot found\n");
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}
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}
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/* remove the device from the pci core */
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pci_remove_bus_device(dslot->dev);
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/* blow away this sysfs entry and other parts. */
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remove_slot(dslot);
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return 0;
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}
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static void cleanup_slots (void)
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{
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struct list_head *tmp;
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struct list_head *next;
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struct dummy_slot *dslot;
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list_for_each_safe (tmp, next, &slot_list) {
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dslot = list_entry (tmp, struct dummy_slot, node);
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remove_slot(dslot);
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}
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}
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static int __init dummyphp_init(void)
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{
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info(DRIVER_DESC "\n");
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return pci_scan_buses();
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}
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static void __exit dummyphp_exit(void)
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{
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cleanup_slots();
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}
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module_init(dummyphp_init);
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module_exit(dummyphp_exit);
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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_param(debug, bool, S_IRUGO | S_IWUSR);
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MODULE_PARM_DESC(debug, "Debugging mode enabled or not");
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