tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 pr_fmt(fmt) "zpci: " fmt
12
13#include <linux/kernel.h>
14#include <linux/slab.h>
15#include <linux/pci.h>
16#include <linux/pci_hotplug.h>
17#include <asm/pci_debug.h>
18#include <asm/sclp.h>
19
20#define SLOT_NAME_SIZE 10
21
22static int enable_slot(struct hotplug_slot *hotplug_slot)
23{
24 struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
25 hotplug_slot);
26 int rc;
27
28 mutex_lock(&zdev->state_lock);
29 if (zdev->state != ZPCI_FN_STATE_STANDBY) {
30 rc = -EIO;
31 goto out;
32 }
33
34 rc = sclp_pci_configure(zdev->fid);
35 zpci_dbg(3, "conf fid:%x, rc:%d\n", zdev->fid, rc);
36 if (rc)
37 goto out;
38 zdev->state = ZPCI_FN_STATE_CONFIGURED;
39
40 rc = zpci_scan_configured_device(zdev, zdev->fh);
41out:
42 mutex_unlock(&zdev->state_lock);
43 return rc;
44}
45
46static int disable_slot(struct hotplug_slot *hotplug_slot)
47{
48 struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
49 hotplug_slot);
50 struct pci_dev *pdev = NULL;
51 int rc;
52
53 mutex_lock(&zdev->state_lock);
54 if (zdev->state != ZPCI_FN_STATE_CONFIGURED) {
55 rc = -EIO;
56 goto out;
57 }
58
59 pdev = pci_get_slot(zdev->zbus->bus, zdev->devfn);
60 if (pdev && pci_num_vf(pdev)) {
61 rc = -EBUSY;
62 goto out;
63 }
64
65 rc = zpci_deconfigure_device(zdev);
66out:
67 if (pdev)
68 pci_dev_put(pdev);
69 mutex_unlock(&zdev->state_lock);
70 return rc;
71}
72
73static int reset_slot(struct hotplug_slot *hotplug_slot, bool probe)
74{
75 struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
76 hotplug_slot);
77 int rc = -EIO;
78
79 /*
80 * If we can't get the zdev->state_lock the device state is
81 * currently undergoing a transition and we bail out - just
82 * the same as if the device's state is not configured at all.
83 */
84 if (!mutex_trylock(&zdev->state_lock))
85 return rc;
86
87 /* We can reset only if the function is configured */
88 if (zdev->state != ZPCI_FN_STATE_CONFIGURED)
89 goto out;
90
91 if (probe) {
92 rc = 0;
93 goto out;
94 }
95
96 rc = zpci_hot_reset_device(zdev);
97out:
98 mutex_unlock(&zdev->state_lock);
99 return rc;
100}
101
102static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
103{
104 struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
105 hotplug_slot);
106
107 *value = zpci_is_device_configured(zdev) ? 1 : 0;
108 return 0;
109}
110
111static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
112{
113 /* if the slot exists it always contains a function */
114 *value = 1;
115 return 0;
116}
117
118static const struct hotplug_slot_ops s390_hotplug_slot_ops = {
119 .enable_slot = enable_slot,
120 .disable_slot = disable_slot,
121 .reset_slot = reset_slot,
122 .get_power_status = get_power_status,
123 .get_adapter_status = get_adapter_status,
124};
125
126int zpci_init_slot(struct zpci_dev *zdev)
127{
128 char name[SLOT_NAME_SIZE];
129 struct zpci_bus *zbus = zdev->zbus;
130
131 zdev->hotplug_slot.ops = &s390_hotplug_slot_ops;
132
133 snprintf(name, SLOT_NAME_SIZE, "%08x", zdev->fid);
134 return pci_hp_register(&zdev->hotplug_slot, zbus->bus,
135 zdev->devfn, name);
136}
137
138void zpci_exit_slot(struct zpci_dev *zdev)
139{
140 pci_hp_deregister(&zdev->hotplug_slot);
141}