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 enable_slot(struct hotplug_slot *hotplug_slot)
24{
25	struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
26					     hotplug_slot);
27	int rc;
28
29	mutex_lock(&zdev->state_lock);
30	if (zdev->state != ZPCI_FN_STATE_STANDBY) {
31		rc = -EIO;
32		goto out;
33	}
34
35	rc = sclp_pci_configure(zdev->fid);
36	zpci_dbg(3, "conf fid:%x, rc:%d\n", zdev->fid, rc);
37	if (rc)
38		goto out;
39	zdev->state = ZPCI_FN_STATE_CONFIGURED;
40
41	rc = zpci_scan_configured_device(zdev, zdev->fh);
42out:
43	mutex_unlock(&zdev->state_lock);
44	return rc;
45}
46
47static int disable_slot(struct hotplug_slot *hotplug_slot)
48{
49	struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
50					     hotplug_slot);
51	struct pci_dev *pdev = NULL;
52	int rc;
53
54	mutex_lock(&zdev->state_lock);
55	if (zdev->state != ZPCI_FN_STATE_CONFIGURED) {
56		rc = -EIO;
57		goto out;
58	}
59
60	pdev = pci_get_slot(zdev->zbus->bus, zdev->devfn);
61	if (pdev && pci_num_vf(pdev)) {
62		pci_dev_put(pdev);
63		rc = -EBUSY;
64		goto out;
65	}
66
67	rc = zpci_deconfigure_device(zdev);
68out:
69	mutex_unlock(&zdev->state_lock);
70	if (pdev)
71		pci_dev_put(pdev);
72	return rc;
73}
74
75static int reset_slot(struct hotplug_slot *hotplug_slot, bool probe)
76{
77	struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
78					     hotplug_slot);
79	int rc = -EIO;
80
81	/*
82	 * If we can't get the zdev->state_lock the device state is
83	 * currently undergoing a transition and we bail out - just
84	 * the same as if the device's state is not configured at all.
85	 */
86	if (!mutex_trylock(&zdev->state_lock))
87		return rc;
88
89	/* We can reset only if the function is configured */
90	if (zdev->state != ZPCI_FN_STATE_CONFIGURED)
91		goto out;
92
93	if (probe) {
94		rc = 0;
95		goto out;
96	}
97
98	rc = zpci_hot_reset_device(zdev);
99out:
100	mutex_unlock(&zdev->state_lock);
101	return rc;
102}
103
104static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
105{
106	struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
107					     hotplug_slot);
108
109	*value = zpci_is_device_configured(zdev) ? 1 : 0;
110	return 0;
111}
112
113static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
114{
115	/* if the slot exits it always contains a function */
116	*value = 1;
117	return 0;
118}
119
120static const struct hotplug_slot_ops s390_hotplug_slot_ops = {
121	.enable_slot =		enable_slot,
122	.disable_slot =		disable_slot,
123	.reset_slot =		reset_slot,
124	.get_power_status =	get_power_status,
125	.get_adapter_status =	get_adapter_status,
126};
127
128int zpci_init_slot(struct zpci_dev *zdev)
129{
130	char name[SLOT_NAME_SIZE];
131	struct zpci_bus *zbus = zdev->zbus;
132
133	zdev->hotplug_slot.ops = &s390_hotplug_slot_ops;
134
135	snprintf(name, SLOT_NAME_SIZE, "%08x", zdev->fid);
136	return pci_hp_register(&zdev->hotplug_slot, zbus->bus,
137			       zdev->devfn, name);
138}
139
140void zpci_exit_slot(struct zpci_dev *zdev)
141{
142	pci_hp_deregister(&zdev->hotplug_slot);
143}
144