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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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7a54f25cef
This makes it possible to build pci hotplug drivers outside of the main kernel tree, and Sam keeps telling me to move local header files to their proper places... Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
372 lines
8.3 KiB
C
372 lines
8.3 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/pci_hotplug.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.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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int retval;
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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 ((dev = pci_get_slot(bus, temp->devfn)) != NULL)
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pci_dev_put(dev);
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else {
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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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retval = pci_bus_add_device(dev);
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if (retval)
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dev_err(&dev->dev, "error adding "
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"device, continuing.\n");
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else
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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 ((dev = pci_get_slot(bus, temp->devfn)) != NULL)
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pci_dev_put(dev);
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else {
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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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retval = pci_bus_add_device(dev);
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if (retval)
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dev_err(&dev->dev, "error adding "
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"device, continuing.\n");
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else
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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_get_slot(dslot->dev->bus,
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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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pci_dev_put(dev);
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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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