summaryrefslogtreecommitdiffstats
path: root/drivers/pci/hotplug/fakephp.c
blob: 6151389fd90304d1b02b364150432d8d3e17bb34 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
/* Works like the fakephp driver used to, except a little better.
 *
 * - It's possible to remove devices with subordinate busses.
 * - New PCI devices that appear via any method, not just a fakephp triggered
 *   rescan, will be noticed.
 * - Devices that are removed via any method, not just a fakephp triggered
 *   removal, will also be noticed.
 *
 * Uses nothing from the pci-hotplug subsystem.
 *
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/list.h>
#include <linux/kobject.h>
#include <linux/sysfs.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/device.h>
#include "../pci.h"

struct legacy_slot {
	struct kobject		kobj;
	struct pci_dev		*dev;
	struct list_head	list;
};

static LIST_HEAD(legacy_list);

static ssize_t legacy_show(struct kobject *kobj, struct attribute *attr,
			   char *buf)
{
	struct legacy_slot *slot = container_of(kobj, typeof(*slot), kobj);
	strcpy(buf, "1\n");
	return 2;
}

static void remove_callback(void *data)
{
	pci_remove_bus_device((struct pci_dev *)data);
}

static ssize_t legacy_store(struct kobject *kobj, struct attribute *attr,
			    const char *buf, size_t len)
{
	struct legacy_slot *slot = container_of(kobj, typeof(*slot), kobj);
	unsigned long val;

	if (strict_strtoul(buf, 0, &val) < 0)
		return -EINVAL;

	if (val)
		pci_rescan_bus(slot->dev->bus);
	else
		sysfs_schedule_callback(&slot->dev->dev.kobj, remove_callback,
					slot->dev, THIS_MODULE);
	return len;
}

static struct attribute *legacy_attrs[] = {
	&(struct attribute){ .name = "power", .mode = 0644 },
	NULL,
};

static void legacy_release(struct kobject *kobj)
{
	struct legacy_slot *slot = container_of(kobj, typeof(*slot), kobj);

	pci_dev_put(slot->dev);
	kfree(slot);
}

static struct kobj_type legacy_ktype = {
	.sysfs_ops = &(struct sysfs_ops){
		.store = legacy_store, .show = legacy_show
	},
	.release = &legacy_release,
	.default_attrs = legacy_attrs,
};

static int legacy_add_slot(struct pci_dev *pdev)
{
	struct legacy_slot *slot = kzalloc(sizeof(*slot), GFP_KERNEL);

	if (!slot)
		return -ENOMEM;

	if (kobject_init_and_add(&slot->kobj, &legacy_ktype,
				 &pci_slots_kset->kobj, "%s",
				 dev_name(&pdev->dev))) {
		dev_warn(&pdev->dev, "Failed to created legacy fake slot\n");
		return -EINVAL;
	}
	slot->dev = pci_dev_get(pdev);

	list_add(&slot->list, &legacy_list);

	return 0;
}

static int legacy_notify(struct notifier_block *nb,
			 unsigned long action, void *data)
{
	struct pci_dev *pdev = to_pci_dev(data);

	if (action == BUS_NOTIFY_ADD_DEVICE) {
		legacy_add_slot(pdev);
	} else if (action == BUS_NOTIFY_DEL_DEVICE) {
		struct legacy_slot *slot;

		list_for_each_entry(slot, &legacy_list, list)
			if (slot->dev == pdev)
				goto found;

		dev_warn(&pdev->dev, "Missing legacy fake slot?");
		return -ENODEV;
found:
		kobject_del(&slot->kobj);
		list_del(&slot->list);
		kobject_put(&slot->kobj);
	}

	return 0;
}

static struct notifier_block legacy_notifier = {
	.notifier_call = legacy_notify
};

static int __init init_legacy(void)
{
	struct pci_dev *pdev = NULL;

	/* Add existing devices */
	while ((pdev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, pdev)))
		legacy_add_slot(pdev);

	/* Be alerted of any new ones */
	bus_register_notifier(&pci_bus_type, &legacy_notifier);
	return 0;
}
module_init(init_legacy);

static void __exit remove_legacy(void)
{
	struct legacy_slot *slot, *tmp;

	bus_unregister_notifier(&pci_bus_type, &legacy_notifier);

	list_for_each_entry_safe(slot, tmp, &legacy_list, list) {
		list_del(&slot->list);
		kobject_del(&slot->kobj);
		kobject_put(&slot->kobj);
	}
}
module_exit(remove_legacy);


MODULE_AUTHOR("Trent Piepho <xyzzy@speakeasy.org>");
MODULE_DESCRIPTION("Legacy version of the fakephp interface");
MODULE_LICENSE("GPL");
OpenPOWER on IntegriCloud