1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Pvpanic Device Support
4 *
5 * Copyright (C) 2013 Fujitsu.
6 * Copyright (C) 2018 ZTE.
7 */
8
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11 #include <linux/acpi.h>
12 #include <linux/kernel.h>
13 #include <linux/kexec.h>
14 #include <linux/module.h>
15 #include <linux/of.h>
16 #include <linux/of_address.h>
17 #include <linux/platform_device.h>
18 #include <linux/types.h>
19 #include <uapi/misc/pvpanic.h>
20
21 static void __iomem *base;
22
23 MODULE_AUTHOR("Hu Tao <hutao@cn.fujitsu.com>");
24 MODULE_DESCRIPTION("pvpanic device driver");
25 MODULE_LICENSE("GPL");
26
27 static void
pvpanic_send_event(unsigned int event)28 pvpanic_send_event(unsigned int event)
29 {
30 iowrite8(event, base);
31 }
32
33 static int
pvpanic_panic_notify(struct notifier_block * nb,unsigned long code,void * unused)34 pvpanic_panic_notify(struct notifier_block *nb, unsigned long code,
35 void *unused)
36 {
37 unsigned int event = PVPANIC_PANICKED;
38
39 if (kexec_crash_loaded())
40 event = PVPANIC_CRASH_LOADED;
41
42 pvpanic_send_event(event);
43
44 return NOTIFY_DONE;
45 }
46
47 static struct notifier_block pvpanic_panic_nb = {
48 .notifier_call = pvpanic_panic_notify,
49 .priority = 1, /* let this called before broken drm_fb_helper */
50 };
51
52 #ifdef CONFIG_ACPI
53 static int pvpanic_add(struct acpi_device *device);
54 static int pvpanic_remove(struct acpi_device *device);
55
56 static const struct acpi_device_id pvpanic_device_ids[] = {
57 { "QEMU0001", 0 },
58 { "", 0 }
59 };
60 MODULE_DEVICE_TABLE(acpi, pvpanic_device_ids);
61
62 static struct acpi_driver pvpanic_driver = {
63 .name = "pvpanic",
64 .class = "QEMU",
65 .ids = pvpanic_device_ids,
66 .ops = {
67 .add = pvpanic_add,
68 .remove = pvpanic_remove,
69 },
70 .owner = THIS_MODULE,
71 };
72
73 static acpi_status
pvpanic_walk_resources(struct acpi_resource * res,void * context)74 pvpanic_walk_resources(struct acpi_resource *res, void *context)
75 {
76 struct resource r;
77
78 if (acpi_dev_resource_io(res, &r)) {
79 #ifdef CONFIG_HAS_IOPORT_MAP
80 base = ioport_map(r.start, resource_size(&r));
81 return AE_OK;
82 #else
83 return AE_ERROR;
84 #endif
85 } else if (acpi_dev_resource_memory(res, &r)) {
86 base = ioremap(r.start, resource_size(&r));
87 return AE_OK;
88 }
89
90 return AE_ERROR;
91 }
92
pvpanic_add(struct acpi_device * device)93 static int pvpanic_add(struct acpi_device *device)
94 {
95 int ret;
96
97 ret = acpi_bus_get_status(device);
98 if (ret < 0)
99 return ret;
100
101 if (!device->status.enabled || !device->status.functional)
102 return -ENODEV;
103
104 acpi_walk_resources(device->handle, METHOD_NAME__CRS,
105 pvpanic_walk_resources, NULL);
106
107 if (!base)
108 return -ENODEV;
109
110 atomic_notifier_chain_register(&panic_notifier_list,
111 &pvpanic_panic_nb);
112
113 return 0;
114 }
115
pvpanic_remove(struct acpi_device * device)116 static int pvpanic_remove(struct acpi_device *device)
117 {
118
119 atomic_notifier_chain_unregister(&panic_notifier_list,
120 &pvpanic_panic_nb);
121 iounmap(base);
122
123 return 0;
124 }
125
pvpanic_register_acpi_driver(void)126 static int pvpanic_register_acpi_driver(void)
127 {
128 return acpi_bus_register_driver(&pvpanic_driver);
129 }
130
pvpanic_unregister_acpi_driver(void)131 static void pvpanic_unregister_acpi_driver(void)
132 {
133 acpi_bus_unregister_driver(&pvpanic_driver);
134 }
135 #else
pvpanic_register_acpi_driver(void)136 static int pvpanic_register_acpi_driver(void)
137 {
138 return -ENODEV;
139 }
140
pvpanic_unregister_acpi_driver(void)141 static void pvpanic_unregister_acpi_driver(void) {}
142 #endif
143
pvpanic_mmio_probe(struct platform_device * pdev)144 static int pvpanic_mmio_probe(struct platform_device *pdev)
145 {
146 base = devm_platform_ioremap_resource(pdev, 0);
147 if (IS_ERR(base))
148 return PTR_ERR(base);
149
150 atomic_notifier_chain_register(&panic_notifier_list,
151 &pvpanic_panic_nb);
152
153 return 0;
154 }
155
pvpanic_mmio_remove(struct platform_device * pdev)156 static int pvpanic_mmio_remove(struct platform_device *pdev)
157 {
158
159 atomic_notifier_chain_unregister(&panic_notifier_list,
160 &pvpanic_panic_nb);
161
162 return 0;
163 }
164
165 static const struct of_device_id pvpanic_mmio_match[] = {
166 { .compatible = "qemu,pvpanic-mmio", },
167 {}
168 };
169 MODULE_DEVICE_TABLE(of, pvpanic_mmio_match);
170
171 static struct platform_driver pvpanic_mmio_driver = {
172 .driver = {
173 .name = "pvpanic-mmio",
174 .of_match_table = pvpanic_mmio_match,
175 },
176 .probe = pvpanic_mmio_probe,
177 .remove = pvpanic_mmio_remove,
178 };
179
pvpanic_mmio_init(void)180 static int __init pvpanic_mmio_init(void)
181 {
182 if (acpi_disabled)
183 return platform_driver_register(&pvpanic_mmio_driver);
184 else
185 return pvpanic_register_acpi_driver();
186 }
187
pvpanic_mmio_exit(void)188 static void __exit pvpanic_mmio_exit(void)
189 {
190 if (acpi_disabled)
191 platform_driver_unregister(&pvpanic_mmio_driver);
192 else
193 pvpanic_unregister_acpi_driver();
194 }
195
196 module_init(pvpanic_mmio_init);
197 module_exit(pvpanic_mmio_exit);
198