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
enable_slot(struct hotplug_slot * hotplug_slot)23 static 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);
42 out:
43 mutex_unlock(&zdev->state_lock);
44 return rc;
45 }
46
disable_slot(struct hotplug_slot * hotplug_slot)47 static 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);
68 out:
69 mutex_unlock(&zdev->state_lock);
70 if (pdev)
71 pci_dev_put(pdev);
72 return rc;
73 }
74
reset_slot(struct hotplug_slot * hotplug_slot,bool probe)75 static 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);
99 out:
100 mutex_unlock(&zdev->state_lock);
101 return rc;
102 }
103
get_power_status(struct hotplug_slot * hotplug_slot,u8 * value)104 static 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
get_adapter_status(struct hotplug_slot * hotplug_slot,u8 * value)113 static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
114 {
115 /* if the slot exists it always contains a function */
116 *value = 1;
117 return 0;
118 }
119
120 static 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
zpci_init_slot(struct zpci_dev * zdev)128 int 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
zpci_exit_slot(struct zpci_dev * zdev)140 void zpci_exit_slot(struct zpci_dev *zdev)
141 {
142 pci_hp_deregister(&zdev->hotplug_slot);
143 }
144