diff options
Diffstat (limited to 'drivers/pci/hotplug/fakephp.c')
| -rw-r--r-- | drivers/pci/hotplug/fakephp.c | 358 |
1 files changed, 358 insertions, 0 deletions
diff --git a/drivers/pci/hotplug/fakephp.c b/drivers/pci/hotplug/fakephp.c new file mode 100644 index 00000000000..8e47fa66e25 --- /dev/null +++ b/drivers/pci/hotplug/fakephp.c @@ -0,0 +1,358 @@ +/* + * Fake PCI Hot Plug Controller Driver + * + * Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com> + * Copyright (C) 2003 IBM Corp. + * Copyright (C) 2003 Rolf Eike Beer <eike-kernel@sf-tec.de> + * + * Based on ideas and code from: + * Vladimir Kondratiev <vladimir.kondratiev@intel.com> + * Rolf Eike Beer <eike-kernel@sf-tec.de> + * + * All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, version 2 of the License. + * + * Send feedback to <greg@kroah.com> + */ + +/* + * + * This driver will "emulate" removing PCI devices from the system. If + * the "power" file is written to with "0" then the specified PCI device + * will be completely removed from the kernel. + * + * WARNING, this does NOT turn off the power to the PCI device. This is + * a "logical" removal, not a physical or electrical removal. + * + * Use this module at your own risk, you have been warned! + * + * Enabling PCI devices is left as an exercise for the reader... + * + */ +#include <linux/config.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/pci.h> +#include <linux/init.h> +#include "pci_hotplug.h" +#include "../pci.h" + +#if !defined(MODULE) + #define MY_NAME "fakephp" +#else + #define MY_NAME THIS_MODULE->name +#endif + +#define dbg(format, arg...) \ + do { \ + if (debug) \ + printk(KERN_DEBUG "%s: " format, \ + MY_NAME , ## arg); \ + } while (0) +#define err(format, arg...) printk(KERN_ERR "%s: " format, MY_NAME , ## arg) +#define info(format, arg...) printk(KERN_INFO "%s: " format, MY_NAME , ## arg) + +#define DRIVER_AUTHOR "Greg Kroah-Hartman <greg@kroah.com>" +#define DRIVER_DESC "Fake PCI Hot Plug Controller Driver" + +struct dummy_slot { + struct list_head node; + struct hotplug_slot *slot; + struct pci_dev *dev; +}; + +static int debug; +static LIST_HEAD(slot_list); + +static int enable_slot (struct hotplug_slot *slot); +static int disable_slot (struct hotplug_slot *slot); + +static struct hotplug_slot_ops dummy_hotplug_slot_ops = { + .owner = THIS_MODULE, + .enable_slot = enable_slot, + .disable_slot = disable_slot, +}; + +static void dummy_release(struct hotplug_slot *slot) +{ + struct dummy_slot *dslot = slot->private; + + list_del(&dslot->node); + kfree(dslot->slot->info); + kfree(dslot->slot); + pci_dev_put(dslot->dev); + kfree(dslot); +} + +static int add_slot(struct pci_dev *dev) +{ + struct dummy_slot *dslot; + struct hotplug_slot *slot; + int retval = -ENOMEM; + + slot = kmalloc(sizeof(struct hotplug_slot), GFP_KERNEL); + if (!slot) + goto error; + memset(slot, 0, sizeof(*slot)); + + slot->info = kmalloc(sizeof(struct hotplug_slot_info), GFP_KERNEL); + if (!slot->info) + goto error_slot; + memset(slot->info, 0, sizeof(struct hotplug_slot_info)); + + slot->info->power_status = 1; + slot->info->max_bus_speed = PCI_SPEED_UNKNOWN; + slot->info->cur_bus_speed = PCI_SPEED_UNKNOWN; + + slot->name = &dev->dev.bus_id[0]; + dbg("slot->name = %s\n", slot->name); + + dslot = kmalloc(sizeof(struct dummy_slot), GFP_KERNEL); + if (!dslot) + goto error_info; + + slot->ops = &dummy_hotplug_slot_ops; + slot->release = &dummy_release; + slot->private = dslot; + + retval = pci_hp_register(slot); + if (retval) { + err("pci_hp_register failed with error %d\n", retval); + goto error_dslot; + } + + dslot->slot = slot; + dslot->dev = pci_dev_get(dev); + list_add (&dslot->node, &slot_list); + return retval; + +error_dslot: + kfree(dslot); +error_info: + kfree(slot->info); +error_slot: + kfree(slot); +error: + return retval; +} + +static int __init pci_scan_buses(void) +{ + struct pci_dev *dev = NULL; + int retval = 0; + + while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) { + retval = add_slot(dev); + if (retval) { + pci_dev_put(dev); + break; + } + } + + return retval; +} + +static void remove_slot(struct dummy_slot *dslot) +{ + int retval; + + dbg("removing slot %s\n", dslot->slot->name); + retval = pci_hp_deregister(dslot->slot); + if (retval) + err("Problem unregistering a slot %s\n", dslot->slot->name); +} + +/** + * Rescan slot. + * Tries hard not to re-enable already existing devices + * also handles scanning of subfunctions + * + * @param temp Device template. Should be set: bus and devfn. + */ +static void pci_rescan_slot(struct pci_dev *temp) +{ + struct pci_bus *bus = temp->bus; + struct pci_dev *dev; + int func; + u8 hdr_type; + if (!pci_read_config_byte(temp, PCI_HEADER_TYPE, &hdr_type)) { + temp->hdr_type = hdr_type & 0x7f; + if (!pci_find_slot(bus->number, temp->devfn)) { + dev = pci_scan_single_device(bus, temp->devfn); + if (dev) { + dbg("New device on %s function %x:%x\n", + bus->name, temp->devfn >> 3, + temp->devfn & 7); + pci_bus_add_device(dev); + add_slot(dev); + } + } + /* multifunction device? */ + if (!(hdr_type & 0x80)) + return; + + /* continue scanning for other functions */ + for (func = 1, temp->devfn++; func < 8; func++, temp->devfn++) { + if (pci_read_config_byte(temp, PCI_HEADER_TYPE, &hdr_type)) + continue; + temp->hdr_type = hdr_type & 0x7f; + + if (!pci_find_slot(bus->number, temp->devfn)) { + dev = pci_scan_single_device(bus, temp->devfn); + if (dev) { + dbg("New device on %s function %x:%x\n", + bus->name, temp->devfn >> 3, + temp->devfn & 7); + pci_bus_add_device(dev); + add_slot(dev); + } + } + } + } +} + + +/** + * Rescan PCI bus. + * call pci_rescan_slot for each possible function of the bus + * + * @param bus + */ +static void pci_rescan_bus(const struct pci_bus *bus) +{ + unsigned int devfn; + struct pci_dev *dev; + dev = kmalloc(sizeof(struct pci_dev), GFP_KERNEL); + if (!dev) + return; + + memset(dev, 0, sizeof(dev)); + dev->bus = (struct pci_bus*)bus; + dev->sysdata = bus->sysdata; + for (devfn = 0; devfn < 0x100; devfn += 8) { + dev->devfn = devfn; + pci_rescan_slot(dev); + } + kfree(dev); +} + +/* recursively scan all buses */ +static void pci_rescan_buses(const struct list_head *list) +{ + const struct list_head *l; + list_for_each(l,list) { + const struct pci_bus *b = pci_bus_b(l); + pci_rescan_bus(b); + pci_rescan_buses(&b->children); + } +} + +/* initiate rescan of all pci buses */ +static inline void pci_rescan(void) { + pci_rescan_buses(&pci_root_buses); +} + + +static int enable_slot(struct hotplug_slot *hotplug_slot) +{ + /* mis-use enable_slot for rescanning of the pci bus */ + pci_rescan(); + return -ENODEV; +} + +/* find the hotplug_slot for the pci_dev */ +static struct hotplug_slot *get_slot_from_dev(struct pci_dev *dev) +{ + struct dummy_slot *dslot; + + list_for_each_entry(dslot, &slot_list, node) { + if (dslot->dev == dev) + return dslot->slot; + } + return NULL; +} + + +static int disable_slot(struct hotplug_slot *slot) +{ + struct dummy_slot *dslot; + struct hotplug_slot *hslot; + struct pci_dev *dev; + int func; + + if (!slot) + return -ENODEV; + dslot = slot->private; + + dbg("%s - physical_slot = %s\n", __FUNCTION__, slot->name); + + /* don't disable bridged devices just yet, we can't handle them easily... */ + if (dslot->dev->subordinate) { + err("Can't remove PCI devices with other PCI devices behind it yet.\n"); + return -ENODEV; + } + /* search for subfunctions and disable them first */ + if (!(dslot->dev->devfn & 7)) { + for (func = 1; func < 8; func++) { + dev = pci_find_slot(dslot->dev->bus->number, + dslot->dev->devfn + func); + if (dev) { + hslot = get_slot_from_dev(dev); + if (hslot) + disable_slot(hslot); + else { + err("Hotplug slot not found for subfunction of PCI device\n"); + return -ENODEV; + } + } else + dbg("No device in slot found\n"); + } + } + + /* remove the device from the pci core */ + pci_remove_bus_device(dslot->dev); + + /* blow away this sysfs entry and other parts. */ + remove_slot(dslot); + + return 0; +} + +static void cleanup_slots (void) +{ + struct list_head *tmp; + struct list_head *next; + struct dummy_slot *dslot; + + list_for_each_safe (tmp, next, &slot_list) { + dslot = list_entry (tmp, struct dummy_slot, node); + remove_slot(dslot); + } + +} + +static int __init dummyphp_init(void) +{ + info(DRIVER_DESC "\n"); + + return pci_scan_buses(); +} + + +static void __exit dummyphp_exit(void) +{ + cleanup_slots(); +} + +module_init(dummyphp_init); +module_exit(dummyphp_exit); + +MODULE_AUTHOR(DRIVER_AUTHOR); +MODULE_DESCRIPTION(DRIVER_DESC); +MODULE_LICENSE("GPL"); +module_param(debug, bool, S_IRUGO | S_IWUSR); +MODULE_PARM_DESC(debug, "Debugging mode enabled or not"); + |