linux/drivers/misc/pvpanic/pvpanic-mmio.c

131 lines
2.9 KiB
C
Raw Normal View History

// SPDX-License-Identifier: GPL-2.0+
/*
* Pvpanic MMIO Device Support
*
* Copyright (C) 2013 Fujitsu.
* Copyright (C) 2018 ZTE.
* Copyright (C) 2021 Oracle.
*/
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/kexec.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <uapi/misc/pvpanic.h>
#include "pvpanic.h"
MODULE_AUTHOR("Hu Tao <hutao@cn.fujitsu.com>");
MODULE_DESCRIPTION("pvpanic-mmio device driver");
MODULE_LICENSE("GPL");
static ssize_t capability_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct pvpanic_instance *pi = dev_get_drvdata(dev);
return sysfs_emit(buf, "%x\n", pi->capability);
}
static DEVICE_ATTR_RO(capability);
static ssize_t events_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct pvpanic_instance *pi = dev_get_drvdata(dev);
return sysfs_emit(buf, "%x\n", pi->events);
}
static ssize_t events_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct pvpanic_instance *pi = dev_get_drvdata(dev);
unsigned int tmp;
int err;
err = kstrtouint(buf, 16, &tmp);
if (err)
return err;
if ((tmp & pi->capability) != tmp)
return -EINVAL;
pi->events = tmp;
return count;
}
static DEVICE_ATTR_RW(events);
static struct attribute *pvpanic_mmio_dev_attrs[] = {
&dev_attr_capability.attr,
&dev_attr_events.attr,
NULL
};
ATTRIBUTE_GROUPS(pvpanic_mmio_dev);
static int pvpanic_mmio_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct pvpanic_instance *pi;
struct resource *res;
void __iomem *base;
res = platform_get_mem_or_io(pdev, 0);
if (!res)
return -EINVAL;
switch (resource_type(res)) {
case IORESOURCE_IO:
base = devm_ioport_map(dev, res->start, resource_size(res));
if (!base)
return -ENOMEM;
break;
case IORESOURCE_MEM:
base = devm_ioremap_resource(dev, res);
if (IS_ERR(base))
return PTR_ERR(base);
break;
default:
return -EINVAL;
}
pi = devm_kmalloc(dev, sizeof(*pi), GFP_KERNEL);
if (!pi)
return -ENOMEM;
pi->base = base;
pi->capability = PVPANIC_PANICKED | PVPANIC_CRASH_LOADED;
/* initialize capability by RDPT */
pi->capability &= ioread8(base);
pi->events = pi->capability;
return devm_pvpanic_probe(dev, pi);
}
static const struct of_device_id pvpanic_mmio_match[] = {
{ .compatible = "qemu,pvpanic-mmio", },
{}
};
MODULE_DEVICE_TABLE(of, pvpanic_mmio_match);
static const struct acpi_device_id pvpanic_device_ids[] = {
{ "QEMU0001", 0 },
{ "", 0 }
};
MODULE_DEVICE_TABLE(acpi, pvpanic_device_ids);
static struct platform_driver pvpanic_mmio_driver = {
.driver = {
.name = "pvpanic-mmio",
.of_match_table = pvpanic_mmio_match,
.acpi_match_table = pvpanic_device_ids,
.dev_groups = pvpanic_mmio_dev_groups,
},
.probe = pvpanic_mmio_probe,
};
module_platform_driver(pvpanic_mmio_driver);