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 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 	if (zdev->state != ZPCI_FN_STATE_STANDBY)
30 		return -EIO;
31 
32 	rc = sclp_pci_configure(zdev->fid);
33 	zpci_dbg(3, "conf fid:%x, rc:%d\n", zdev->fid, rc);
34 	if (rc)
35 		return rc;
36 	zdev->state = ZPCI_FN_STATE_CONFIGURED;
37 
38 	return zpci_scan_configured_device(zdev, zdev->fh);
39 }
40 
41 static int disable_slot(struct hotplug_slot *hotplug_slot)
42 {
43 	struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
44 					     hotplug_slot);
45 	struct pci_dev *pdev;
46 
47 	if (zdev->state != ZPCI_FN_STATE_CONFIGURED)
48 		return -EIO;
49 
50 	pdev = pci_get_slot(zdev->zbus->bus, zdev->devfn);
51 	if (pdev && pci_num_vf(pdev)) {
52 		pci_dev_put(pdev);
53 		return -EBUSY;
54 	}
55 	pci_dev_put(pdev);
56 
57 	return zpci_deconfigure_device(zdev);
58 }
59 
60 static int reset_slot(struct hotplug_slot *hotplug_slot, bool probe)
61 {
62 	struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
63 					     hotplug_slot);
64 
65 	if (zdev->state != ZPCI_FN_STATE_CONFIGURED)
66 		return -EIO;
67 	/*
68 	 * We can't take the zdev->lock as reset_slot may be called during
69 	 * probing and/or device removal which already happens under the
70 	 * zdev->lock. Instead the user should use the higher level
71 	 * pci_reset_function() or pci_bus_reset() which hold the PCI device
72 	 * lock preventing concurrent removal. If not using these functions
73 	 * holding the PCI device lock is required.
74 	 */
75 
76 	/* As long as the function is configured we can reset */
77 	if (probe)
78 		return 0;
79 
80 	return zpci_hot_reset_device(zdev);
81 }
82 
83 static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
84 {
85 	struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
86 					     hotplug_slot);
87 
88 	*value = zpci_is_device_configured(zdev) ? 1 : 0;
89 	return 0;
90 }
91 
92 static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
93 {
94 	/* if the slot exits it always contains a function */
95 	*value = 1;
96 	return 0;
97 }
98 
99 static const struct hotplug_slot_ops s390_hotplug_slot_ops = {
100 	.enable_slot =		enable_slot,
101 	.disable_slot =		disable_slot,
102 	.reset_slot =		reset_slot,
103 	.get_power_status =	get_power_status,
104 	.get_adapter_status =	get_adapter_status,
105 };
106 
107 int zpci_init_slot(struct zpci_dev *zdev)
108 {
109 	char name[SLOT_NAME_SIZE];
110 	struct zpci_bus *zbus = zdev->zbus;
111 
112 	zdev->hotplug_slot.ops = &s390_hotplug_slot_ops;
113 
114 	snprintf(name, SLOT_NAME_SIZE, "%08x", zdev->fid);
115 	return pci_hp_register(&zdev->hotplug_slot, zbus->bus,
116 			       zdev->devfn, name);
117 }
118 
119 void zpci_exit_slot(struct zpci_dev *zdev)
120 {
121 	pci_hp_deregister(&zdev->hotplug_slot);
122 }
123