[mirror_ubuntu-bionic-kernel.git] / drivers / pci / hotplug / fakephp.c

/*
 * 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/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/slab.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 = kzalloc(sizeof(struct hotplug_slot), GFP_KERNEL);
	if (!slot)
		goto error;

	slot->info = kzalloc(sizeof(struct hotplug_slot_info), GFP_KERNEL);
	if (!slot->info)
		goto error_slot;

	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;
	int retval;
	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);
				retval = pci_bus_add_device(dev);
				if (retval)
					dev_err(&dev->dev, "error adding "
						"device, continuing.\n");
				else
					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);
					retval = pci_bus_add_device(dev);
					if (retval)
						dev_err(&dev->dev, "error adding "
							"device, continuing.\n");
					else
						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 = kzalloc(sizeof(struct pci_dev), GFP_KERNEL);
	if (!dev)
		return;

	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");
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Fake PCI Hot Plug Controller Driver
	3	*
	4	* Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
	5	* Copyright (C) 2003 IBM Corp.
	6	* Copyright (C) 2003 Rolf Eike Beer <eike-kernel@sf-tec.de>
	7	*
	8	* Based on ideas and code from:
	9	* Vladimir Kondratiev <vladimir.kondratiev@intel.com>
	10	* Rolf Eike Beer <eike-kernel@sf-tec.de>
	11	*
	12	* All rights reserved.
	13	*
	14	* This program is free software; you can redistribute it and/or modify
	15	* it under the terms of the GNU General Public License as published by
	16	* the Free Software Foundation, version 2 of the License.
	17	*
	18	* Send feedback to <greg@kroah.com>
	19	*/
	20
	21	/*
	22	*
	23	* This driver will "emulate" removing PCI devices from the system. If
	24	* the "power" file is written to with "0" then the specified PCI device
	25	* will be completely removed from the kernel.
	26	*
	27	* WARNING, this does NOT turn off the power to the PCI device. This is
	28	* a "logical" removal, not a physical or electrical removal.
	29	*
	30	* Use this module at your own risk, you have been warned!
	31	*
	32	* Enabling PCI devices is left as an exercise for the reader...
	33	*
	34	*/
1da177e4 LT	35	#include <linux/kernel.h>
	36	#include <linux/module.h>
	37	#include <linux/pci.h>
	38	#include <linux/init.h>
4e57b681 TS	39	#include <linux/string.h>
4e57b681 TS	40	#include <linux/slab.h>
1da177e4 LT	41	#include "pci_hotplug.h"
	42	#include "../pci.h"
	43
	44	#if !defined(MODULE)
	45	#define MY_NAME "fakephp"
	46	#else
	47	#define MY_NAME THIS_MODULE->name
	48	#endif
	49
	50	#define dbg(format, arg...) \
	51	do { \
	52	if (debug) \
	53	printk(KERN_DEBUG "%s: " format, \
	54	MY_NAME , ## arg); \
	55	} while (0)
	56	#define err(format, arg...) printk(KERN_ERR "%s: " format, MY_NAME , ## arg)
	57	#define info(format, arg...) printk(KERN_INFO "%s: " format, MY_NAME , ## arg)
	58
	59	#define DRIVER_AUTHOR "Greg Kroah-Hartman <greg@kroah.com>"
	60	#define DRIVER_DESC "Fake PCI Hot Plug Controller Driver"
	61
	62	struct dummy_slot {
	63	struct list_head node;
	64	struct hotplug_slot *slot;
	65	struct pci_dev *dev;
	66	};
	67
	68	static int debug;
	69	static LIST_HEAD(slot_list);
	70
	71	static int enable_slot (struct hotplug_slot *slot);
	72	static int disable_slot (struct hotplug_slot *slot);
	73
	74	static struct hotplug_slot_ops dummy_hotplug_slot_ops = {
	75	.owner = THIS_MODULE,
	76	.enable_slot = enable_slot,
	77	.disable_slot = disable_slot,
	78	};
	79
	80	static void dummy_release(struct hotplug_slot *slot)
	81	{
	82	struct dummy_slot *dslot = slot->private;
	83
	84	list_del(&dslot->node);
	85	kfree(dslot->slot->info);
	86	kfree(dslot->slot);
	87	pci_dev_put(dslot->dev);
	88	kfree(dslot);
	89	}
	90
	91	static int add_slot(struct pci_dev *dev)
	92	{
	93	struct dummy_slot *dslot;
	94	struct hotplug_slot *slot;
	95	int retval = -ENOMEM;
	96
f5afe806	97	slot = kzalloc(sizeof(struct hotplug_slot), GFP_KERNEL);
1da177e4 LT	98	if (!slot)
1da177e4 LT	99	goto error;
1da177e4	100
f5afe806	101	slot->info = kzalloc(sizeof(struct hotplug_slot_info), GFP_KERNEL);
1da177e4 LT	102	if (!slot->info)
1da177e4 LT	103	goto error_slot;
1da177e4 LT	104
	105	slot->info->power_status = 1;
	106	slot->info->max_bus_speed = PCI_SPEED_UNKNOWN;
	107	slot->info->cur_bus_speed = PCI_SPEED_UNKNOWN;
	108
	109	slot->name = &dev->dev.bus_id[0];
	110	dbg("slot->name = %s\n", slot->name);
	111
	112	dslot = kmalloc(sizeof(struct dummy_slot), GFP_KERNEL);
	113	if (!dslot)
	114	goto error_info;
	115
	116	slot->ops = &dummy_hotplug_slot_ops;
	117	slot->release = &dummy_release;
	118	slot->private = dslot;
	119
	120	retval = pci_hp_register(slot);
	121	if (retval) {
	122	err("pci_hp_register failed with error %d\n", retval);
	123	goto error_dslot;
	124	}
	125
	126	dslot->slot = slot;
	127	dslot->dev = pci_dev_get(dev);
	128	list_add (&dslot->node, &slot_list);
	129	return retval;
	130
	131	error_dslot:
	132	kfree(dslot);
	133	error_info:
	134	kfree(slot->info);
	135	error_slot:
	136	kfree(slot);
	137	error:
	138	return retval;
	139	}
	140
	141	static int __init pci_scan_buses(void)
	142	{
	143	struct pci_dev *dev = NULL;
	144	int retval = 0;
	145
	146	while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
	147	retval = add_slot(dev);
	148	if (retval) {
	149	pci_dev_put(dev);
	150	break;
	151	}
	152	}
	153
	154	return retval;
	155	}
	156
	157	static void remove_slot(struct dummy_slot *dslot)
	158	{
	159	int retval;
	160
	161	dbg("removing slot %s\n", dslot->slot->name);
	162	retval = pci_hp_deregister(dslot->slot);
	163	if (retval)
	164	err("Problem unregistering a slot %s\n", dslot->slot->name);
	165	}
	166
	167	/**
168	* Rescan slot.
169	* Tries hard not to re-enable already existing devices
170	* also handles scanning of subfunctions
171	*
172	* @param temp Device template. Should be set: bus and devfn.
173	*/
174	static void pci_rescan_slot(struct pci_dev *temp)
175	{
176	struct pci_bus *bus = temp->bus;
177	struct pci_dev *dev;
178	int func;
b19441af	179	int retval;
1da177e4	180	u8 hdr_type;
b19441af	181
1da177e4 LT	182	if (!pci_read_config_byte(temp, PCI_HEADER_TYPE, &hdr_type)) {
	183	temp->hdr_type = hdr_type & 0x7f;
	184	if (!pci_find_slot(bus->number, temp->devfn)) {
	185	dev = pci_scan_single_device(bus, temp->devfn);
	186	if (dev) {
	187	dbg("New device on %s function %x:%x\n",
	188	bus->name, temp->devfn >> 3,
	189	temp->devfn & 7);
b19441af GKH	190	retval = pci_bus_add_device(dev);
	191	if (retval)
	192	dev_err(&dev->dev, "error adding "
	193	"device, continuing.\n");
	194	else
	195	add_slot(dev);
1da177e4 LT	196	}
	197	}
	198	/* multifunction device? */
	199	if (!(hdr_type & 0x80))
	200	return;
	201
	202	/* continue scanning for other functions */
	203	for (func = 1, temp->devfn++; func < 8; func++, temp->devfn++) {
	204	if (pci_read_config_byte(temp, PCI_HEADER_TYPE, &hdr_type))
	205	continue;
	206	temp->hdr_type = hdr_type & 0x7f;
	207
	208	if (!pci_find_slot(bus->number, temp->devfn)) {
	209	dev = pci_scan_single_device(bus, temp->devfn);
	210	if (dev) {
	211	dbg("New device on %s function %x:%x\n",
	212	bus->name, temp->devfn >> 3,
	213	temp->devfn & 7);
b19441af GKH	214	retval = pci_bus_add_device(dev);
	215	if (retval)
	216	dev_err(&dev->dev, "error adding "
	217	"device, continuing.\n");
	218	else
	219	add_slot(dev);
1da177e4 LT	220	}
	221	}
	222	}
	223	}
	224	}
	225
	226
	227	/**
	228	* Rescan PCI bus.
	229	* call pci_rescan_slot for each possible function of the bus
	230	*
	231	* @param bus
	232	*/
	233	static void pci_rescan_bus(const struct pci_bus *bus)
	234	{
	235	unsigned int devfn;
	236	struct pci_dev *dev;
f5afe806	237	dev = kzalloc(sizeof(struct pci_dev), GFP_KERNEL);
1da177e4 LT	238	if (!dev)
	239	return;
	240
1da177e4 LT	241	dev->bus = (struct pci_bus*)bus;
	242	dev->sysdata = bus->sysdata;
	243	for (devfn = 0; devfn < 0x100; devfn += 8) {
	244	dev->devfn = devfn;
	245	pci_rescan_slot(dev);
	246	}
	247	kfree(dev);
	248	}
	249
	250	/* recursively scan all buses */
	251	static void pci_rescan_buses(const struct list_head *list)
	252	{
	253	const struct list_head *l;
	254	list_for_each(l,list) {
	255	const struct pci_bus *b = pci_bus_b(l);
	256	pci_rescan_bus(b);
	257	pci_rescan_buses(&b->children);
	258	}
	259	}
	260
	261	/* initiate rescan of all pci buses */
	262	static inline void pci_rescan(void) {
	263	pci_rescan_buses(&pci_root_buses);
	264	}
	265
	266
	267	static int enable_slot(struct hotplug_slot *hotplug_slot)
	268	{
	269	/* mis-use enable_slot for rescanning of the pci bus */
	270	pci_rescan();
	271	return -ENODEV;
	272	}
	273
	274	/* find the hotplug_slot for the pci_dev */
	275	static struct hotplug_slot get_slot_from_dev(struct pci_dev dev)
	276	{
	277	struct dummy_slot *dslot;
	278
	279	list_for_each_entry(dslot, &slot_list, node) {
	280	if (dslot->dev == dev)
	281	return dslot->slot;
	282	}
	283	return NULL;
	284	}
	285
	286
	287	static int disable_slot(struct hotplug_slot *slot)
	288	{
	289	struct dummy_slot *dslot;
	290	struct hotplug_slot *hslot;
	291	struct pci_dev *dev;
	292	int func;
	293
	294	if (!slot)
	295	return -ENODEV;
	296	dslot = slot->private;
	297
	298	dbg("%s - physical_slot = %s\n", __FUNCTION__, slot->name);
	299
	300	/* don't disable bridged devices just yet, we can't handle them easily... */
	301	if (dslot->dev->subordinate) {
	302	err("Can't remove PCI devices with other PCI devices behind it yet.\n");
	303	return -ENODEV;
	304	}
305	/* search for subfunctions and disable them first */
306	if (!(dslot->dev->devfn & 7)) {
307	for (func = 1; func < 8; func++) {
308	dev = pci_find_slot(dslot->dev->bus->number,
309	dslot->dev->devfn + func);
310	if (dev) {
311	hslot = get_slot_from_dev(dev);
312	if (hslot)
313	disable_slot(hslot);
314	else {
315	err("Hotplug slot not found for subfunction of PCI device\n");
316	return -ENODEV;
317	}
318	} else
319	dbg("No device in slot found\n");
320	}
321	}
322
323	/* remove the device from the pci core */
324	pci_remove_bus_device(dslot->dev);
325
326	/* blow away this sysfs entry and other parts. */
327	remove_slot(dslot);
328
329	return 0;
330	}
331
332	static void cleanup_slots (void)
333	{
334	struct list_head *tmp;
335	struct list_head *next;
336	struct dummy_slot *dslot;
337
338	list_for_each_safe (tmp, next, &slot_list) {
339	dslot = list_entry (tmp, struct dummy_slot, node);
340	remove_slot(dslot);
341	}
342
343	}
344
345	static int __init dummyphp_init(void)
346	{
347	info(DRIVER_DESC "\n");
348
349	return pci_scan_buses();
350	}
351
352
353	static void __exit dummyphp_exit(void)
354	{
355	cleanup_slots();
356	}
357
358	module_init(dummyphp_init);
359	module_exit(dummyphp_exit);
360
361	MODULE_AUTHOR(DRIVER_AUTHOR);
362	MODULE_DESCRIPTION(DRIVER_DESC);
363	MODULE_LICENSE("GPL");
364	module_param(debug, bool, S_IRUGO \| S_IWUSR);
365	MODULE_PARM_DESC(debug, "Debugging mode enabled or not");
366