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 * 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/io.h>
12#include <linux/kernel.h>
13#include <linux/kexec.h>
14#include <linux/mod_devicetable.h>
15#include <linux/module.h>
16#include <linux/platform_device.h>
17#include <linux/types.h>
18
19#include <uapi/misc/pvpanic.h>
20
21static void __iomem *base;
22
23MODULE_AUTHOR("Hu Tao <hutao@cn.fujitsu.com>");
24MODULE_DESCRIPTION("pvpanic device driver");
25MODULE_LICENSE("GPL");
26
27static void
28pvpanic_send_event(unsigned int event)
29{
30 iowrite8(event, base);
31}
32
33static int
34pvpanic_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
47static 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
52static int pvpanic_mmio_probe(struct platform_device *pdev)
53{
54 struct device *dev = &pdev->dev;
55 struct resource *res;
56
57 res = platform_get_mem_or_io(pdev, 0);
58 if (!res)
59 return -EINVAL;
60
61 switch (resource_type(res)) {
62 case IORESOURCE_IO:
63 base = devm_ioport_map(dev, res->start, resource_size(res));
64 if (!base)
65 return -ENOMEM;
66 break;
67 case IORESOURCE_MEM:
68 base = devm_ioremap_resource(dev, res);
69 if (IS_ERR(base))
70 return PTR_ERR(base);
71 break;
72 default:
73 return -EINVAL;
74 }
75
76 atomic_notifier_chain_register(&panic_notifier_list,
77 &pvpanic_panic_nb);
78
79 return 0;
80}
81
82static int pvpanic_mmio_remove(struct platform_device *pdev)
83{
84
85 atomic_notifier_chain_unregister(&panic_notifier_list,
86 &pvpanic_panic_nb);
87
88 return 0;
89}
90
91static const struct of_device_id pvpanic_mmio_match[] = {
92 { .compatible = "qemu,pvpanic-mmio", },
93 {}
94};
95
96static const struct acpi_device_id pvpanic_device_ids[] = {
97 { "QEMU0001", 0 },
98 { "", 0 }
99};
100MODULE_DEVICE_TABLE(acpi, pvpanic_device_ids);
101
102static struct platform_driver pvpanic_mmio_driver = {
103 .driver = {
104 .name = "pvpanic-mmio",
105 .of_match_table = pvpanic_mmio_match,
106 .acpi_match_table = pvpanic_device_ids,
107 },
108 .probe = pvpanic_mmio_probe,
109 .remove = pvpanic_mmio_remove,
110};
111module_platform_driver(pvpanic_mmio_driver);