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/module.h>
14 #include <linux/of.h>
15 #include <linux/of_address.h>
16 #include <linux/platform_device.h>
17 #include <linux/types.h>
18
19 static void __iomem *base;
20
21 #define PVPANIC_PANICKED (1 << 0)
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 pvpanic_send_event(PVPANIC_PANICKED);
38 return NOTIFY_DONE;
39 }
40
41 static struct notifier_block pvpanic_panic_nb = {
42 .notifier_call = pvpanic_panic_notify,
43 .priority = 1, /* let this called before broken drm_fb_helper */
44 };
45
46 #ifdef CONFIG_ACPI
47 static int pvpanic_add(struct acpi_device *device);
48 static int pvpanic_remove(struct acpi_device *device);
49
50 static const struct acpi_device_id pvpanic_device_ids[] = {
51 { "QEMU0001", 0 },
52 { "", 0 }
53 };
54 MODULE_DEVICE_TABLE(acpi, pvpanic_device_ids);
55
56 static struct acpi_driver pvpanic_driver = {
57 .name = "pvpanic",
58 .class = "QEMU",
59 .ids = pvpanic_device_ids,
60 .ops = {
61 .add = pvpanic_add,
62 .remove = pvpanic_remove,
63 },
64 .owner = THIS_MODULE,
65 };
66
67 static acpi_status
pvpanic_walk_resources(struct acpi_resource * res,void * context)68 pvpanic_walk_resources(struct acpi_resource *res, void *context)
69 {
70 struct resource r;
71
72 if (acpi_dev_resource_io(res, &r)) {
73 #ifdef CONFIG_HAS_IOPORT_MAP
74 base = ioport_map(r.start, resource_size(&r));
75 return AE_OK;
76 #else
77 return AE_ERROR;
78 #endif
79 } else if (acpi_dev_resource_memory(res, &r)) {
80 base = ioremap(r.start, resource_size(&r));
81 return AE_OK;
82 }
83
84 return AE_ERROR;
85 }
86
pvpanic_add(struct acpi_device * device)87 static int pvpanic_add(struct acpi_device *device)
88 {
89 int ret;
90
91 ret = acpi_bus_get_status(device);
92 if (ret < 0)
93 return ret;
94
95 if (!device->status.enabled || !device->status.functional)
96 return -ENODEV;
97
98 acpi_walk_resources(device->handle, METHOD_NAME__CRS,
99 pvpanic_walk_resources, NULL);
100
101 if (!base)
102 return -ENODEV;
103
104 atomic_notifier_chain_register(&panic_notifier_list,
105 &pvpanic_panic_nb);
106
107 return 0;
108 }
109
pvpanic_remove(struct acpi_device * device)110 static int pvpanic_remove(struct acpi_device *device)
111 {
112
113 atomic_notifier_chain_unregister(&panic_notifier_list,
114 &pvpanic_panic_nb);
115 iounmap(base);
116
117 return 0;
118 }
119
pvpanic_register_acpi_driver(void)120 static int pvpanic_register_acpi_driver(void)
121 {
122 return acpi_bus_register_driver(&pvpanic_driver);
123 }
124
pvpanic_unregister_acpi_driver(void)125 static void pvpanic_unregister_acpi_driver(void)
126 {
127 acpi_bus_unregister_driver(&pvpanic_driver);
128 }
129 #else
pvpanic_register_acpi_driver(void)130 static int pvpanic_register_acpi_driver(void)
131 {
132 return -ENODEV;
133 }
134
pvpanic_unregister_acpi_driver(void)135 static void pvpanic_unregister_acpi_driver(void) {}
136 #endif
137
pvpanic_mmio_probe(struct platform_device * pdev)138 static int pvpanic_mmio_probe(struct platform_device *pdev)
139 {
140 struct resource *mem;
141
142 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
143 if (!mem)
144 return -EINVAL;
145
146 base = devm_ioremap_resource(&pdev->dev, mem);
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
170 static struct platform_driver pvpanic_mmio_driver = {
171 .driver = {
172 .name = "pvpanic-mmio",
173 .of_match_table = pvpanic_mmio_match,
174 },
175 .probe = pvpanic_mmio_probe,
176 .remove = pvpanic_mmio_remove,
177 };
178
pvpanic_mmio_init(void)179 static int __init pvpanic_mmio_init(void)
180 {
181 if (acpi_disabled)
182 return platform_driver_register(&pvpanic_mmio_driver);
183 else
184 return pvpanic_register_acpi_driver();
185 }
186
pvpanic_mmio_exit(void)187 static void __exit pvpanic_mmio_exit(void)
188 {
189 if (acpi_disabled)
190 platform_driver_unregister(&pvpanic_mmio_driver);
191 else
192 pvpanic_unregister_acpi_driver();
193 }
194
195 module_init(pvpanic_mmio_init);
196 module_exit(pvpanic_mmio_exit);
197