6 files changed, 409 insertions, 0 deletions

diff --git a/drivers/misc/pvpanic/Kconfig b/drivers/misc/pvpanic/Kconfig
new file mode 100644
index 000000000..12d40a21f
--- /dev/null
+++ b/drivers/misc/pvpanic/Kconfig
@@ -0,0 +1,27 @@
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Pvpanic Kconfig
+#
+# Copyright (C) 2021 Oracle.
+#
+
+config PVPANIC
+	bool "pvpanic device support"
+	help
+	  This option allows to select a specific pvpanic device driver.
+	  pvpanic is a paravirtualized device provided by QEMU; it lets
+	  a virtual machine (guest) communicate panic events to the host.
+
+config PVPANIC_MMIO
+	tristate "pvpanic MMIO device support"
+	depends on HAS_IOMEM && (ACPI || OF) && PVPANIC
+	help
+	  This driver provides support for the MMIO pvpanic device.
+
+config PVPANIC_PCI
+	tristate "pvpanic PCI device support"
+	depends on PCI && PVPANIC
+	help
+	  This driver provides support for the PCI pvpanic device.
+	  pvpanic is a paravirtualized device provided by QEMU which
+	  forwards the panic events from the guest to the host.
diff --git a/drivers/misc/pvpanic/Makefile b/drivers/misc/pvpanic/Makefile
new file mode 100644
index 000000000..9471df7d4
--- /dev/null
+++ b/drivers/misc/pvpanic/Makefile
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Pvpanic Makefile
+#
+# Copyright (C) 2021 Oracle.
+#
+obj-$(CONFIG_PVPANIC_MMIO)	+= pvpanic.o pvpanic-mmio.o
+obj-$(CONFIG_PVPANIC_PCI)	+= pvpanic.o pvpanic-pci.o
diff --git a/drivers/misc/pvpanic/pvpanic-mmio.c b/drivers/misc/pvpanic/pvpanic-mmio.c
new file mode 100644
index 000000000..eb97167c0
--- /dev/null
+++ b/drivers/misc/pvpanic/pvpanic-mmio.c
@@ -0,0 +1,130 @@
+// 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);
diff --git a/drivers/misc/pvpanic/pvpanic-pci.c b/drivers/misc/pvpanic/pvpanic-pci.c
new file mode 100644
index 000000000..07eddb5ea
--- /dev/null
+++ b/drivers/misc/pvpanic/pvpanic-pci.c
@@ -0,0 +1,109 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  Pvpanic PCI Device Support
+ *
+ *  Copyright (C) 2021 Oracle.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+
+#include <uapi/misc/pvpanic.h>
+
+#include "pvpanic.h"
+
+#define PCI_VENDOR_ID_REDHAT             0x1b36
+#define PCI_DEVICE_ID_REDHAT_PVPANIC     0x0011
+
+MODULE_AUTHOR("Mihai Carabas <mihai.carabas@oracle.com>");
+MODULE_DESCRIPTION("pvpanic 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_pci_dev_attrs[] = {
+	&dev_attr_capability.attr,
+	&dev_attr_events.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(pvpanic_pci_dev);
+
+static int pvpanic_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
+{
+	struct pvpanic_instance *pi;
+	void __iomem *base;
+	int ret;
+
+	ret = pcim_enable_device(pdev);
+	if (ret < 0)
+		return ret;
+
+	base = pcim_iomap(pdev, 0, 0);
+	if (!base)
+		return -ENOMEM;
+
+	pi = devm_kmalloc(&pdev->dev, sizeof(*pi), GFP_KERNEL);
+	if (!pi)
+		return -ENOMEM;
+
+	pi->base = base;
+	pi->capability = PVPANIC_PANICKED | PVPANIC_CRASH_LOADED;
+
+	/* initlize capability by RDPT */
+	pi->capability &= ioread8(base);
+	pi->events = pi->capability;
+
+	return devm_pvpanic_probe(&pdev->dev, pi);
+}
+
+static const struct pci_device_id pvpanic_pci_id_tbl[]  = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_REDHAT, PCI_DEVICE_ID_REDHAT_PVPANIC)},
+	{}
+};
+MODULE_DEVICE_TABLE(pci, pvpanic_pci_id_tbl);
+
+static struct pci_driver pvpanic_pci_driver = {
+	.name =         "pvpanic-pci",
+	.id_table =     pvpanic_pci_id_tbl,
+	.probe =        pvpanic_pci_probe,
+	.driver = {
+		.dev_groups = pvpanic_pci_dev_groups,
+	},
+};
+module_pci_driver(pvpanic_pci_driver);
diff --git a/drivers/misc/pvpanic/pvpanic.c b/drivers/misc/pvpanic/pvpanic.c
new file mode 100644
index 000000000..049a12006
--- /dev/null
+++ b/drivers/misc/pvpanic/pvpanic.c
@@ -0,0 +1,115 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  Pvpanic 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/panic_notifier.h>
+#include <linux/types.h>
+#include <linux/cdev.h>
+#include <linux/list.h>
+
+#include <uapi/misc/pvpanic.h>
+
+#include "pvpanic.h"
+
+MODULE_AUTHOR("Mihai Carabas <mihai.carabas@oracle.com>");
+MODULE_DESCRIPTION("pvpanic device driver");
+MODULE_LICENSE("GPL");
+
+static struct list_head pvpanic_list;
+static spinlock_t pvpanic_lock;
+
+static void
+pvpanic_send_event(unsigned int event)
+{
+	struct pvpanic_instance *pi_cur;
+
+	if (!spin_trylock(&pvpanic_lock))
+		return;
+
+	list_for_each_entry(pi_cur, &pvpanic_list, list) {
+		if (event & pi_cur->capability & pi_cur->events)
+			iowrite8(event, pi_cur->base);
+	}
+	spin_unlock(&pvpanic_lock);
+}
+
+static int
+pvpanic_panic_notify(struct notifier_block *nb, unsigned long code, void *unused)
+{
+	unsigned int event = PVPANIC_PANICKED;
+
+	if (kexec_crash_loaded())
+		event = PVPANIC_CRASH_LOADED;
+
+	pvpanic_send_event(event);
+
+	return NOTIFY_DONE;
+}
+
+/*
+ * Call our notifier very early on panic, deferring the
+ * action taken to the hypervisor.
+ */
+static struct notifier_block pvpanic_panic_nb = {
+	.notifier_call = pvpanic_panic_notify,
+	.priority = INT_MAX,
+};
+
+static void pvpanic_remove(void *param)
+{
+	struct pvpanic_instance *pi_cur, *pi_next;
+	struct pvpanic_instance *pi = param;
+
+	spin_lock(&pvpanic_lock);
+	list_for_each_entry_safe(pi_cur, pi_next, &pvpanic_list, list) {
+		if (pi_cur == pi) {
+			list_del(&pi_cur->list);
+			break;
+		}
+	}
+	spin_unlock(&pvpanic_lock);
+}
+
+int devm_pvpanic_probe(struct device *dev, struct pvpanic_instance *pi)
+{
+	if (!pi || !pi->base)
+		return -EINVAL;
+
+	spin_lock(&pvpanic_lock);
+	list_add(&pi->list, &pvpanic_list);
+	spin_unlock(&pvpanic_lock);
+
+	dev_set_drvdata(dev, pi);
+
+	return devm_add_action_or_reset(dev, pvpanic_remove, pi);
+}
+EXPORT_SYMBOL_GPL(devm_pvpanic_probe);
+
+static int pvpanic_init(void)
+{
+	INIT_LIST_HEAD(&pvpanic_list);
+	spin_lock_init(&pvpanic_lock);
+
+	atomic_notifier_chain_register(&panic_notifier_list, &pvpanic_panic_nb);
+
+	return 0;
+}
+module_init(pvpanic_init);
+
+static void pvpanic_exit(void)
+{
+	atomic_notifier_chain_unregister(&panic_notifier_list, &pvpanic_panic_nb);
+
+}
+module_exit(pvpanic_exit);
diff --git a/drivers/misc/pvpanic/pvpanic.h b/drivers/misc/pvpanic/pvpanic.h
new file mode 100644
index 000000000..493545951
--- /dev/null
+++ b/drivers/misc/pvpanic/pvpanic.h
@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  Pvpanic Device Support
+ *
+ *  Copyright (C) 2021 Oracle.
+ */
+
+#ifndef PVPANIC_H_
+#define PVPANIC_H_
+
+struct pvpanic_instance {
+	void __iomem *base;
+	unsigned int capability;
+	unsigned int events;
+	struct list_head list;
+};
+
+int devm_pvpanic_probe(struct device *dev, struct pvpanic_instance *pi);
+
+#endif /* PVPANIC_H_ */