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	if (zdev->state != ZPCI_FN_STATE_STANDBY)
30		return -EIO;
31
32	rc = sclp_pci_configure(zdev->fid);
33	zpci_dbg(3, "conf fid:%x, rc:%d\n", zdev->fid, rc);
34	if (rc)
35		return rc;
36	zdev->state = ZPCI_FN_STATE_CONFIGURED;
37
38	return zpci_scan_configured_device(zdev, zdev->fh);
39}
40
41static int disable_slot(struct hotplug_slot *hotplug_slot)
42{
43	struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
44					     hotplug_slot);
45	struct pci_dev *pdev;
46
47	if (zdev->state != ZPCI_FN_STATE_CONFIGURED)
48		return -EIO;
49
50	pdev = pci_get_slot(zdev->zbus->bus, zdev->devfn);
51	if (pdev && pci_num_vf(pdev)) {
52		pci_dev_put(pdev);
53		return -EBUSY;
54	}
55	pci_dev_put(pdev);
56
57	return zpci_deconfigure_device(zdev);
58}
59
60static int reset_slot(struct hotplug_slot *hotplug_slot, bool probe)
61{
62	struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
63					     hotplug_slot);
64
65	if (zdev->state != ZPCI_FN_STATE_CONFIGURED)
66		return -EIO;
67	/*
68	 * We can't take the zdev->lock as reset_slot may be called during
69	 * probing and/or device removal which already happens under the
70	 * zdev->lock. Instead the user should use the higher level
71	 * pci_reset_function() or pci_bus_reset() which hold the PCI device
72	 * lock preventing concurrent removal. If not using these functions
73	 * holding the PCI device lock is required.
74	 */
75
76	/* As long as the function is configured we can reset */
77	if (probe)
78		return 0;
79
80	return zpci_hot_reset_device(zdev);
81}
82
83static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
84{
85	struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
86					     hotplug_slot);
87
88	*value = zpci_is_device_configured(zdev) ? 1 : 0;
89	return 0;
90}
91
92static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
93{
94	/* if the slot exits it always contains a function */
95	*value = 1;
96	return 0;
97}
98
99static const struct hotplug_slot_ops s390_hotplug_slot_ops = {
100	.enable_slot =		enable_slot,
101	.disable_slot =		disable_slot,
102	.reset_slot =		reset_slot,
103	.get_power_status =	get_power_status,
104	.get_adapter_status =	get_adapter_status,
105};
106
107int zpci_init_slot(struct zpci_dev *zdev)
108{
109	char name[SLOT_NAME_SIZE];
110	struct zpci_bus *zbus = zdev->zbus;
111
112	zdev->hotplug_slot.ops = &s390_hotplug_slot_ops;
113
114	snprintf(name, SLOT_NAME_SIZE, "%08x", zdev->fid);
115	return pci_hp_register(&zdev->hotplug_slot, zbus->bus,
116			       zdev->devfn, name);
117}
118
119void zpci_exit_slot(struct zpci_dev *zdev)
120{
121	pci_hp_deregister(&zdev->hotplug_slot);
122}
123