1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * PCI Hot Plug Controller Driver for System z
4 *
5 * Copyright 2012 IBM Corp.
6 *
7 * Author(s):
8 *   Jan Glauber <jang@linux.vnet.ibm.com>
9 */
10
11#define KMSG_COMPONENT "zpci"
12#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
13
14#include <linux/kernel.h>
15#include <linux/slab.h>
16#include <linux/pci.h>
17#include <linux/pci_hotplug.h>
18#include <asm/pci_debug.h>
19#include <asm/sclp.h>
20
21#define SLOT_NAME_SIZE	10
22
23static int zpci_fn_configured(enum zpci_state state)
24{
25	return state == ZPCI_FN_STATE_CONFIGURED ||
26	       state == ZPCI_FN_STATE_ONLINE;
27}
28
29static inline int zdev_configure(struct zpci_dev *zdev)
30{
31	int ret = sclp_pci_configure(zdev->fid);
32
33	zpci_dbg(3, "conf fid:%x, rc:%d\n", zdev->fid, ret);
34	if (!ret)
35		zdev->state = ZPCI_FN_STATE_CONFIGURED;
36
37	return ret;
38}
39
40static inline int zdev_deconfigure(struct zpci_dev *zdev)
41{
42	int ret = sclp_pci_deconfigure(zdev->fid);
43
44	zpci_dbg(3, "deconf fid:%x, rc:%d\n", zdev->fid, ret);
45	if (!ret)
46		zdev->state = ZPCI_FN_STATE_STANDBY;
47
48	return ret;
49}
50
51static int enable_slot(struct hotplug_slot *hotplug_slot)
52{
53	struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
54					     hotplug_slot);
55	struct zpci_bus *zbus = zdev->zbus;
56	int rc;
57
58	if (zdev->state != ZPCI_FN_STATE_STANDBY)
59		return -EIO;
60
61	rc = zdev_configure(zdev);
62	if (rc)
63		return rc;
64
65	rc = zpci_enable_device(zdev);
66	if (rc)
67		goto out_deconfigure;
68
69	pci_scan_slot(zbus->bus, zdev->devfn);
70	pci_lock_rescan_remove();
71	pci_bus_add_devices(zbus->bus);
72	pci_unlock_rescan_remove();
73
74	return rc;
75
76out_deconfigure:
77	zdev_deconfigure(zdev);
78	return rc;
79}
80
81static int disable_slot(struct hotplug_slot *hotplug_slot)
82{
83	struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
84					     hotplug_slot);
85	struct pci_dev *pdev;
86	int rc;
87
88	if (!zpci_fn_configured(zdev->state))
89		return -EIO;
90
91	pdev = pci_get_slot(zdev->zbus->bus, zdev->devfn);
92	if (pdev && pci_num_vf(pdev)) {
93		pci_dev_put(pdev);
94		return -EBUSY;
95	}
96	pci_dev_put(pdev);
97
98	zpci_remove_device(zdev, false);
99
100	rc = zpci_disable_device(zdev);
101	if (rc)
102		return rc;
103
104	return zdev_deconfigure(zdev);
105}
106
107static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
108{
109	struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
110					     hotplug_slot);
111
112	*value = zpci_is_device_configured(zdev) ? 1 : 0;
113	return 0;
114}
115
116static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
117{
118	/* if the slot exits it always contains a function */
119	*value = 1;
120	return 0;
121}
122
123static const struct hotplug_slot_ops s390_hotplug_slot_ops = {
124	.enable_slot =		enable_slot,
125	.disable_slot =		disable_slot,
126	.get_power_status =	get_power_status,
127	.get_adapter_status =	get_adapter_status,
128};
129
130int zpci_init_slot(struct zpci_dev *zdev)
131{
132	char name[SLOT_NAME_SIZE];
133	struct zpci_bus *zbus = zdev->zbus;
134
135	zdev->hotplug_slot.ops = &s390_hotplug_slot_ops;
136
137	snprintf(name, SLOT_NAME_SIZE, "%08x", zdev->fid);
138	return pci_hp_register(&zdev->hotplug_slot, zbus->bus,
139			       zdev->devfn, name);
140}
141
142void zpci_exit_slot(struct zpci_dev *zdev)
143{
144	pci_hp_deregister(&zdev->hotplug_slot);
145}
146