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 get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
61 {
62 	struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
63 					     hotplug_slot);
64 
65 	switch (zdev->state) {
66 	case ZPCI_FN_STATE_STANDBY:
67 		*value = 0;
68 		break;
69 	default:
70 		*value = 1;
71 		break;
72 	}
73 	return 0;
74 }
75 
76 static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
77 {
78 	/* if the slot exits it always contains a function */
79 	*value = 1;
80 	return 0;
81 }
82 
83 static const struct hotplug_slot_ops s390_hotplug_slot_ops = {
84 	.enable_slot =		enable_slot,
85 	.disable_slot =		disable_slot,
86 	.get_power_status =	get_power_status,
87 	.get_adapter_status =	get_adapter_status,
88 };
89 
90 int zpci_init_slot(struct zpci_dev *zdev)
91 {
92 	char name[SLOT_NAME_SIZE];
93 	struct zpci_bus *zbus = zdev->zbus;
94 
95 	zdev->hotplug_slot.ops = &s390_hotplug_slot_ops;
96 
97 	snprintf(name, SLOT_NAME_SIZE, "%08x", zdev->fid);
98 	return pci_hp_register(&zdev->hotplug_slot, zbus->bus,
99 			       zdev->devfn, name);
100 }
101 
102 void zpci_exit_slot(struct zpci_dev *zdev)
103 {
104 	pci_hp_deregister(&zdev->hotplug_slot);
105 }
106