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 	struct zpci_bus *zbus = zdev->zbus;
56 	int rc;
57 
58 	if (zdev->state != ZPCI_FN_STATE_STANDBY)
59 		return -EIO;
60 
61 	rc = zdev_configure(zdev);
62 	if (rc)
63 		return rc;
64 
65 	rc = zpci_enable_device(zdev);
66 	if (rc)
67 		goto out_deconfigure;
68 
69 	pci_scan_slot(zbus->bus, zdev->devfn);
70 	pci_lock_rescan_remove();
71 	pci_bus_add_devices(zbus->bus);
72 	pci_unlock_rescan_remove();
73 
74 	return rc;
75 
76 out_deconfigure:
77 	zdev_deconfigure(zdev);
78 	return rc;
79 }
80 
81 static int disable_slot(struct hotplug_slot *hotplug_slot)
82 {
83 	struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
84 					     hotplug_slot);
85 	struct pci_dev *pdev;
86 	int rc;
87 
88 	if (!zpci_fn_configured(zdev->state))
89 		return -EIO;
90 
91 	pdev = pci_get_slot(zdev->zbus->bus, zdev->devfn);
92 	if (pdev && pci_num_vf(pdev)) {
93 		pci_dev_put(pdev);
94 		return -EBUSY;
95 	}
96 
97 	zpci_remove_device(zdev);
98 
99 	rc = zpci_disable_device(zdev);
100 	if (rc)
101 		return rc;
102 
103 	return zdev_deconfigure(zdev);
104 }
105 
106 static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
107 {
108 	struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
109 					     hotplug_slot);
110 
111 	switch (zdev->state) {
112 	case ZPCI_FN_STATE_STANDBY:
113 		*value = 0;
114 		break;
115 	default:
116 		*value = 1;
117 		break;
118 	}
119 	return 0;
120 }
121 
122 static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
123 {
124 	/* if the slot exits it always contains a function */
125 	*value = 1;
126 	return 0;
127 }
128 
129 static const struct hotplug_slot_ops s390_hotplug_slot_ops = {
130 	.enable_slot =		enable_slot,
131 	.disable_slot =		disable_slot,
132 	.get_power_status =	get_power_status,
133 	.get_adapter_status =	get_adapter_status,
134 };
135 
136 int zpci_init_slot(struct zpci_dev *zdev)
137 {
138 	char name[SLOT_NAME_SIZE];
139 	struct zpci_bus *zbus = zdev->zbus;
140 
141 	zdev->hotplug_slot.ops = &s390_hotplug_slot_ops;
142 
143 	snprintf(name, SLOT_NAME_SIZE, "%08x", zdev->fid);
144 	return pci_hp_register(&zdev->hotplug_slot, zbus->bus,
145 			       zdev->devfn, name);
146 }
147 
148 void zpci_exit_slot(struct zpci_dev *zdev)
149 {
150 	pci_hp_deregister(&zdev->hotplug_slot);
151 }
152