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 static LIST_HEAD(s390_hotplug_slot_list);
23
zpci_fn_configured(enum zpci_state state)24 static int zpci_fn_configured(enum zpci_state state)
25 {
26 return state == ZPCI_FN_STATE_CONFIGURED ||
27 state == ZPCI_FN_STATE_ONLINE;
28 }
29
30 /*
31 * struct slot - slot information for each *physical* slot
32 */
33 struct slot {
34 struct list_head slot_list;
35 struct hotplug_slot *hotplug_slot;
36 struct zpci_dev *zdev;
37 };
38
slot_configure(struct slot * slot)39 static inline int slot_configure(struct slot *slot)
40 {
41 int ret = sclp_pci_configure(slot->zdev->fid);
42
43 zpci_dbg(3, "conf fid:%x, rc:%d\n", slot->zdev->fid, ret);
44 if (!ret)
45 slot->zdev->state = ZPCI_FN_STATE_CONFIGURED;
46
47 return ret;
48 }
49
slot_deconfigure(struct slot * slot)50 static inline int slot_deconfigure(struct slot *slot)
51 {
52 int ret = sclp_pci_deconfigure(slot->zdev->fid);
53
54 zpci_dbg(3, "deconf fid:%x, rc:%d\n", slot->zdev->fid, ret);
55 if (!ret)
56 slot->zdev->state = ZPCI_FN_STATE_STANDBY;
57
58 return ret;
59 }
60
enable_slot(struct hotplug_slot * hotplug_slot)61 static int enable_slot(struct hotplug_slot *hotplug_slot)
62 {
63 struct slot *slot = hotplug_slot->private;
64 int rc;
65
66 if (slot->zdev->state != ZPCI_FN_STATE_STANDBY)
67 return -EIO;
68
69 rc = slot_configure(slot);
70 if (rc)
71 return rc;
72
73 rc = zpci_enable_device(slot->zdev);
74 if (rc)
75 goto out_deconfigure;
76
77 pci_scan_slot(slot->zdev->bus, ZPCI_DEVFN);
78 pci_lock_rescan_remove();
79 pci_bus_add_devices(slot->zdev->bus);
80 pci_unlock_rescan_remove();
81
82 return rc;
83
84 out_deconfigure:
85 slot_deconfigure(slot);
86 return rc;
87 }
88
disable_slot(struct hotplug_slot * hotplug_slot)89 static int disable_slot(struct hotplug_slot *hotplug_slot)
90 {
91 struct slot *slot = hotplug_slot->private;
92 struct pci_dev *pdev;
93 int rc;
94
95 if (!zpci_fn_configured(slot->zdev->state))
96 return -EIO;
97
98 pdev = pci_get_slot(slot->zdev->bus, ZPCI_DEVFN);
99 if (pdev) {
100 pci_stop_and_remove_bus_device_locked(pdev);
101 pci_dev_put(pdev);
102 }
103
104 rc = zpci_disable_device(slot->zdev);
105 if (rc)
106 return rc;
107
108 return slot_deconfigure(slot);
109 }
110
get_power_status(struct hotplug_slot * hotplug_slot,u8 * value)111 static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
112 {
113 struct slot *slot = hotplug_slot->private;
114
115 switch (slot->zdev->state) {
116 case ZPCI_FN_STATE_STANDBY:
117 *value = 0;
118 break;
119 default:
120 *value = 1;
121 break;
122 }
123 return 0;
124 }
125
get_adapter_status(struct hotplug_slot * hotplug_slot,u8 * value)126 static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
127 {
128 /* if the slot exits it always contains a function */
129 *value = 1;
130 return 0;
131 }
132
133 static struct hotplug_slot_ops s390_hotplug_slot_ops = {
134 .enable_slot = enable_slot,
135 .disable_slot = disable_slot,
136 .get_power_status = get_power_status,
137 .get_adapter_status = get_adapter_status,
138 };
139
zpci_init_slot(struct zpci_dev * zdev)140 int zpci_init_slot(struct zpci_dev *zdev)
141 {
142 struct hotplug_slot *hotplug_slot;
143 struct hotplug_slot_info *info;
144 char name[SLOT_NAME_SIZE];
145 struct slot *slot;
146 int rc;
147
148 if (!zdev)
149 return 0;
150
151 slot = kzalloc(sizeof(*slot), GFP_KERNEL);
152 if (!slot)
153 goto error;
154
155 hotplug_slot = kzalloc(sizeof(*hotplug_slot), GFP_KERNEL);
156 if (!hotplug_slot)
157 goto error_hp;
158 hotplug_slot->private = slot;
159
160 slot->hotplug_slot = hotplug_slot;
161 slot->zdev = zdev;
162
163 info = kzalloc(sizeof(*info), GFP_KERNEL);
164 if (!info)
165 goto error_info;
166 hotplug_slot->info = info;
167
168 hotplug_slot->ops = &s390_hotplug_slot_ops;
169
170 get_power_status(hotplug_slot, &info->power_status);
171 get_adapter_status(hotplug_slot, &info->adapter_status);
172
173 snprintf(name, SLOT_NAME_SIZE, "%08x", zdev->fid);
174 rc = pci_hp_register(slot->hotplug_slot, zdev->bus,
175 ZPCI_DEVFN, name);
176 if (rc)
177 goto error_reg;
178
179 list_add(&slot->slot_list, &s390_hotplug_slot_list);
180 return 0;
181
182 error_reg:
183 kfree(info);
184 error_info:
185 kfree(hotplug_slot);
186 error_hp:
187 kfree(slot);
188 error:
189 return -ENOMEM;
190 }
191
zpci_exit_slot(struct zpci_dev * zdev)192 void zpci_exit_slot(struct zpci_dev *zdev)
193 {
194 struct slot *slot, *next;
195
196 list_for_each_entry_safe(slot, next, &s390_hotplug_slot_list,
197 slot_list) {
198 if (slot->zdev != zdev)
199 continue;
200 list_del(&slot->slot_list);
201 pci_hp_deregister(slot->hotplug_slot);
202 kfree(slot->hotplug_slot->info);
203 kfree(slot->hotplug_slot);
204 kfree(slot);
205 }
206 }
207
