161 lines
3.4 KiB
C
161 lines
3.4 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Pvpanic Device Support
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*
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* Copyright (C) 2013 Fujitsu.
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* Copyright (C) 2018 ZTE.
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/io.h>
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#include <linux/kernel.h>
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#include <linux/kexec.h>
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#include <linux/mod_devicetable.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/types.h>
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#include <uapi/misc/pvpanic.h>
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static void __iomem *base;
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static unsigned int capability = PVPANIC_PANICKED | PVPANIC_CRASH_LOADED;
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static unsigned int events;
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static ssize_t capability_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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return sysfs_emit(buf, "%x\n", capability);
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}
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static DEVICE_ATTR_RO(capability);
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static ssize_t events_show(struct device *dev, struct device_attribute *attr, char *buf)
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{
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return sysfs_emit(buf, "%x\n", events);
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}
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static ssize_t events_store(struct device *dev, struct device_attribute *attr,
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const char *buf, size_t count)
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{
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unsigned int tmp;
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int err;
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err = kstrtouint(buf, 16, &tmp);
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if (err)
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return err;
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if ((tmp & capability) != tmp)
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return -EINVAL;
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events = tmp;
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return count;
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}
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static DEVICE_ATTR_RW(events);
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static struct attribute *pvpanic_dev_attrs[] = {
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&dev_attr_capability.attr,
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&dev_attr_events.attr,
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NULL
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};
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ATTRIBUTE_GROUPS(pvpanic_dev);
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MODULE_AUTHOR("Hu Tao <hutao@cn.fujitsu.com>");
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MODULE_DESCRIPTION("pvpanic device driver");
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MODULE_LICENSE("GPL");
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static void
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pvpanic_send_event(unsigned int event)
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{
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if (event & capability & events)
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iowrite8(event, base);
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}
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static int
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pvpanic_panic_notify(struct notifier_block *nb, unsigned long code,
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void *unused)
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{
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unsigned int event = PVPANIC_PANICKED;
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if (kexec_crash_loaded())
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event = PVPANIC_CRASH_LOADED;
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pvpanic_send_event(event);
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return NOTIFY_DONE;
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}
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static struct notifier_block pvpanic_panic_nb = {
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.notifier_call = pvpanic_panic_notify,
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.priority = 1, /* let this called before broken drm_fb_helper */
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};
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static int pvpanic_mmio_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct resource *res;
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res = platform_get_mem_or_io(pdev, 0);
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if (!res)
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return -EINVAL;
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switch (resource_type(res)) {
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case IORESOURCE_IO:
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base = devm_ioport_map(dev, res->start, resource_size(res));
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if (!base)
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return -ENOMEM;
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break;
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case IORESOURCE_MEM:
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base = devm_ioremap_resource(dev, res);
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if (IS_ERR(base))
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return PTR_ERR(base);
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break;
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default:
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return -EINVAL;
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}
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/* initlize capability by RDPT */
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capability &= ioread8(base);
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events = capability;
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if (capability)
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atomic_notifier_chain_register(&panic_notifier_list,
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&pvpanic_panic_nb);
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return 0;
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}
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static int pvpanic_mmio_remove(struct platform_device *pdev)
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{
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if (capability)
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atomic_notifier_chain_unregister(&panic_notifier_list,
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&pvpanic_panic_nb);
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return 0;
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}
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static const struct of_device_id pvpanic_mmio_match[] = {
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{ .compatible = "qemu,pvpanic-mmio", },
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{}
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};
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static const struct acpi_device_id pvpanic_device_ids[] = {
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{ "QEMU0001", 0 },
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{ "", 0 }
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};
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MODULE_DEVICE_TABLE(acpi, pvpanic_device_ids);
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static struct platform_driver pvpanic_mmio_driver = {
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.driver = {
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.name = "pvpanic-mmio",
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.of_match_table = pvpanic_mmio_match,
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.acpi_match_table = pvpanic_device_ids,
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.dev_groups = pvpanic_dev_groups,
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},
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.probe = pvpanic_mmio_probe,
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.remove = pvpanic_mmio_remove,
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};
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module_platform_driver(pvpanic_mmio_driver);
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