1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 *  Pvpanic MMIO Device Support
  4 *
  5 *  Copyright (C) 2013 Fujitsu.
  6 *  Copyright (C) 2018 ZTE.
  7 *  Copyright (C) 2021 Oracle.
  8 */
  9
 10#include <linux/io.h>
 11#include <linux/kernel.h>
 12#include <linux/kexec.h>
 13#include <linux/mod_devicetable.h>
 14#include <linux/module.h>
 15#include <linux/platform_device.h>
 16#include <linux/types.h>
 17#include <linux/slab.h>
 18
 19#include <uapi/misc/pvpanic.h>
 20
 21#include "pvpanic.h"
 22
 23MODULE_AUTHOR("Hu Tao <hutao@cn.fujitsu.com>");
 24MODULE_DESCRIPTION("pvpanic-mmio device driver");
 25MODULE_LICENSE("GPL");
 26
 27static ssize_t capability_show(struct device *dev,
 28			       struct device_attribute *attr, char *buf)
 29{
 30	struct pvpanic_instance *pi = dev_get_drvdata(dev);
 31
 32	return sysfs_emit(buf, "%x\n", pi->capability);
 33}
 34static DEVICE_ATTR_RO(capability);
 35
 36static ssize_t events_show(struct device *dev,  struct device_attribute *attr, char *buf)
 37{
 38	struct pvpanic_instance *pi = dev_get_drvdata(dev);
 39
 40	return sysfs_emit(buf, "%x\n", pi->events);
 41}
 42
 43static ssize_t events_store(struct device *dev,  struct device_attribute *attr,
 44			    const char *buf, size_t count)
 45{
 46	struct pvpanic_instance *pi = dev_get_drvdata(dev);
 47	unsigned int tmp;
 48	int err;
 49
 50	err = kstrtouint(buf, 16, &tmp);
 51	if (err)
 52		return err;
 53
 54	if ((tmp & pi->capability) != tmp)
 55		return -EINVAL;
 56
 57	pi->events = tmp;
 58
 59	return count;
 60}
 61static DEVICE_ATTR_RW(events);
 62
 63static struct attribute *pvpanic_mmio_dev_attrs[] = {
 64	&dev_attr_capability.attr,
 65	&dev_attr_events.attr,
 66	NULL
 67};
 68ATTRIBUTE_GROUPS(pvpanic_mmio_dev);
 69
 70static int pvpanic_mmio_probe(struct platform_device *pdev)
 71{
 72	struct device *dev = &pdev->dev;
 73	struct pvpanic_instance *pi;
 74	struct resource *res;
 75	void __iomem *base;
 76
 77	res = platform_get_mem_or_io(pdev, 0);
 78	if (!res)
 79		return -EINVAL;
 80
 81	switch (resource_type(res)) {
 82	case IORESOURCE_IO:
 83		base = devm_ioport_map(dev, res->start, resource_size(res));
 84		if (!base)
 85			return -ENOMEM;
 86		break;
 87	case IORESOURCE_MEM:
 88		base = devm_ioremap_resource(dev, res);
 89		if (IS_ERR(base))
 90			return PTR_ERR(base);
 91		break;
 92	default:
 93		return -EINVAL;
 94	}
 95
 96	pi = devm_kmalloc(dev, sizeof(*pi), GFP_KERNEL);
 97	if (!pi)
 98		return -ENOMEM;
 99
100	pi->base = base;
101	pi->capability = PVPANIC_PANICKED | PVPANIC_CRASH_LOADED;
102
103	/* initlize capability by RDPT */
104	pi->capability &= ioread8(base);
105	pi->events = pi->capability;
106
107	return devm_pvpanic_probe(dev, pi);
108}
109
110static const struct of_device_id pvpanic_mmio_match[] = {
111	{ .compatible = "qemu,pvpanic-mmio", },
112	{}
113};
114MODULE_DEVICE_TABLE(of, pvpanic_mmio_match);
115
116static const struct acpi_device_id pvpanic_device_ids[] = {
117	{ "QEMU0001", 0 },
118	{ "", 0 }
119};
120MODULE_DEVICE_TABLE(acpi, pvpanic_device_ids);
121
122static struct platform_driver pvpanic_mmio_driver = {
123	.driver = {
124		.name = "pvpanic-mmio",
125		.of_match_table = pvpanic_mmio_match,
126		.acpi_match_table = pvpanic_device_ids,
127		.dev_groups = pvpanic_mmio_dev_groups,
128	},
129	.probe = pvpanic_mmio_probe,
130};
131module_platform_driver(pvpanic_mmio_driver);