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 
23 static int zpci_fn_configured(enum zpci_state state)
24 {
25 	return state == ZPCI_FN_STATE_CONFIGURED ||
26 	       state == ZPCI_FN_STATE_ONLINE;
27 }
28 
29 static inline int zdev_configure(struct zpci_dev *zdev)
30 {
31 	int ret = sclp_pci_configure(zdev->fid);
32 
33 	zpci_dbg(3, "conf fid:%x, rc:%d\n", zdev->fid, ret);
34 	if (!ret)
35 		zdev->state = ZPCI_FN_STATE_CONFIGURED;
36 
37 	return ret;
38 }
39 
40 static inline int zdev_deconfigure(struct zpci_dev *zdev)
41 {
42 	int ret = sclp_pci_deconfigure(zdev->fid);
43 
44 	zpci_dbg(3, "deconf fid:%x, rc:%d\n", zdev->fid, ret);
45 	if (!ret)
46 		zdev->state = ZPCI_FN_STATE_STANDBY;
47 
48 	return ret;
49 }
50 
51 static int enable_slot(struct hotplug_slot *hotplug_slot)
52 {
53 	struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
54 					     hotplug_slot);
55 	int rc;
56 
57 	if (zdev->state != ZPCI_FN_STATE_STANDBY)
58 		return -EIO;
59 
60 	rc = zdev_configure(zdev);
61 	if (rc)
62 		return rc;
63 
64 	rc = zpci_enable_device(zdev);
65 	if (rc)
66 		goto out_deconfigure;
67 
68 	pci_scan_slot(zdev->bus, ZPCI_DEVFN);
69 	pci_lock_rescan_remove();
70 	pci_bus_add_devices(zdev->bus);
71 	pci_unlock_rescan_remove();
72 
73 	return rc;
74 
75 out_deconfigure:
76 	zdev_deconfigure(zdev);
77 	return rc;
78 }
79 
80 static int disable_slot(struct hotplug_slot *hotplug_slot)
81 {
82 	struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
83 					     hotplug_slot);
84 	struct pci_dev *pdev;
85 	int rc;
86 
87 	if (!zpci_fn_configured(zdev->state))
88 		return -EIO;
89 
90 	pdev = pci_get_slot(zdev->bus, ZPCI_DEVFN);
91 	if (pdev) {
92 		pci_stop_and_remove_bus_device_locked(pdev);
93 		pci_dev_put(pdev);
94 	}
95 
96 	rc = zpci_disable_device(zdev);
97 	if (rc)
98 		return rc;
99 
100 	return zdev_deconfigure(zdev);
101 }
102 
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 	switch (zdev->state) {
109 	case ZPCI_FN_STATE_STANDBY:
110 		*value = 0;
111 		break;
112 	default:
113 		*value = 1;
114 		break;
115 	}
116 	return 0;
117 }
118 
119 static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
120 {
121 	/* if the slot exits it always contains a function */
122 	*value = 1;
123 	return 0;
124 }
125 
126 static const struct hotplug_slot_ops s390_hotplug_slot_ops = {
127 	.enable_slot =		enable_slot,
128 	.disable_slot =		disable_slot,
129 	.get_power_status =	get_power_status,
130 	.get_adapter_status =	get_adapter_status,
131 };
132 
133 int zpci_init_slot(struct zpci_dev *zdev)
134 {
135 	char name[SLOT_NAME_SIZE];
136 
137 	zdev->hotplug_slot.ops = &s390_hotplug_slot_ops;
138 
139 	snprintf(name, SLOT_NAME_SIZE, "%08x", zdev->fid);
140 	return pci_hp_register(&zdev->hotplug_slot, zdev->bus,
141 			       ZPCI_DEVFN, name);
142 }
143 
144 void zpci_exit_slot(struct zpci_dev *zdev)
145 {
146 	pci_hp_deregister(&zdev->hotplug_slot);
147 }
148