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 rc = -EBUSY;
63 goto out;
64 }
65
66 rc = zpci_deconfigure_device(zdev);
67 out:
68 if (pdev)
69 pci_dev_put(pdev);
70 mutex_unlock(&zdev->state_lock);
71 return rc;
72 }
73
reset_slot(struct hotplug_slot * hotplug_slot,bool probe)74 static int reset_slot(struct hotplug_slot *hotplug_slot, bool probe)
75 {
76 struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
77 hotplug_slot);
78 int rc = -EIO;
79
80 /*
81 * If we can't get the zdev->state_lock the device state is
82 * currently undergoing a transition and we bail out - just
83 * the same as if the device's state is not configured at all.
84 */
85 if (!mutex_trylock(&zdev->state_lock))
86 return rc;
87
88 /* We can reset only if the function is configured */
89 if (zdev->state != ZPCI_FN_STATE_CONFIGURED)
90 goto out;
91
92 if (probe) {
93 rc = 0;
94 goto out;
95 }
96
97 rc = zpci_hot_reset_device(zdev);
98 out:
99 mutex_unlock(&zdev->state_lock);
100 return rc;
101 }
102
get_power_status(struct hotplug_slot * hotplug_slot,u8 * value)103 static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
104 {
105 struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
106 hotplug_slot);
107
108 *value = zpci_is_device_configured(zdev) ? 1 : 0;
109 return 0;
110 }
111
get_adapter_status(struct hotplug_slot * hotplug_slot,u8 * value)112 static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
113 {
114 /* if the slot exists it always contains a function */
115 *value = 1;
116 return 0;
117 }
118
119 static const struct hotplug_slot_ops s390_hotplug_slot_ops = {
120 .enable_slot = enable_slot,
121 .disable_slot = disable_slot,
122 .reset_slot = reset_slot,
123 .get_power_status = get_power_status,
124 .get_adapter_status = get_adapter_status,
125 };
126
zpci_init_slot(struct zpci_dev * zdev)127 int zpci_init_slot(struct zpci_dev *zdev)
128 {
129 char name[SLOT_NAME_SIZE];
130 struct zpci_bus *zbus = zdev->zbus;
131
132 zdev->hotplug_slot.ops = &s390_hotplug_slot_ops;
133
134 snprintf(name, SLOT_NAME_SIZE, "%08x", zdev->fid);
135 return pci_hp_register(&zdev->hotplug_slot, zbus->bus,
136 zdev->devfn, name);
137 }
138
zpci_exit_slot(struct zpci_dev * zdev)139 void zpci_exit_slot(struct zpci_dev *zdev)
140 {
141 pci_hp_deregister(&zdev->hotplug_slot);
142 }
143