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path: root/drivers/pci/hotplug/fakephp.c
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Diffstat (limited to 'drivers/pci/hotplug/fakephp.c')
-rw-r--r--drivers/pci/hotplug/fakephp.c358
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");
+