1 files changed, 123 insertions, 6 deletions

diff --git a/drivers/misc/pvpanic/pvpanic.c b/drivers/misc/pvpanic/pvpanic.c
index 049a12006348..17c0eb549463 100644
--- a/drivers/misc/pvpanic/pvpanic.c
+++ b/drivers/misc/pvpanic/pvpanic.c
@@ -7,16 +7,22 @@
  *  Copyright (C) 2021 Oracle.
  */
 
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/gfp_types.h>
 #include <linux/io.h>
-#include <linux/kernel.h>
 #include <linux/kexec.h>
+#include <linux/kstrtox.h>
+#include <linux/limits.h>
+#include <linux/list.h>
 #include <linux/mod_devicetable.h>
 #include <linux/module.h>
-#include <linux/platform_device.h>
 #include <linux/panic_notifier.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+#include <linux/spinlock.h>
+#include <linux/sysfs.h>
 #include <linux/types.h>
-#include <linux/cdev.h>
-#include <linux/list.h>
 
 #include <uapi/misc/pvpanic.h>
 
@@ -26,6 +32,14 @@ MODULE_AUTHOR("Mihai Carabas <mihai.carabas@oracle.com>");
 MODULE_DESCRIPTION("pvpanic device driver");
 MODULE_LICENSE("GPL");
 
+struct pvpanic_instance {
+	void __iomem *base;
+	unsigned int capability;
+	unsigned int events;
+	struct sys_off_handler *sys_off;
+	struct list_head list;
+};
+
 static struct list_head pvpanic_list;
 static spinlock_t pvpanic_lock;
 
@@ -66,6 +80,39 @@ static struct notifier_block pvpanic_panic_nb = {
 	.priority = INT_MAX,
 };
 
+static int pvpanic_sys_off(struct sys_off_data *data)
+{
+	pvpanic_send_event(PVPANIC_SHUTDOWN);
+
+	return NOTIFY_DONE;
+}
+
+static void pvpanic_synchronize_sys_off_handler(struct device *dev, struct pvpanic_instance *pi)
+{
+	/* The kernel core has logic to fall back to system halt if no
+	 * sys_off_handler is registered.
+	 * When the pvpanic sys_off_handler is disabled via sysfs the kernel
+	 * should use that fallback logic, so the handler needs to be unregistered.
+	 */
+
+	struct sys_off_handler *sys_off;
+
+	if (!(pi->events & PVPANIC_SHUTDOWN) == !pi->sys_off)
+		return;
+
+	if (!pi->sys_off) {
+		sys_off = register_sys_off_handler(SYS_OFF_MODE_POWER_OFF, SYS_OFF_PRIO_LOW,
+						   pvpanic_sys_off, NULL);
+		if (IS_ERR(sys_off))
+			dev_warn(dev, "Could not register sys_off_handler: %pe\n", sys_off);
+		else
+			pi->sys_off = sys_off;
+	} else {
+		unregister_sys_off_handler(pi->sys_off);
+		pi->sys_off = NULL;
+	}
+}
+
 static void pvpanic_remove(void *param)
 {
 	struct pvpanic_instance *pi_cur, *pi_next;
@@ -79,13 +126,83 @@ static void pvpanic_remove(void *param)
 		}
 	}
 	spin_unlock(&pvpanic_lock);
+
+	unregister_sys_off_handler(pi->sys_off);
+}
+
+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);
 
-int devm_pvpanic_probe(struct device *dev, struct pvpanic_instance *pi)
+static ssize_t events_show(struct device *dev, struct device_attribute *attr, char *buf)
 {
-	if (!pi || !pi->base)
+	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;
+	pvpanic_synchronize_sys_off_handler(dev, pi);
+
+	return count;
+}
+static DEVICE_ATTR_RW(events);
+
+static struct attribute *pvpanic_dev_attrs[] = {
+	&dev_attr_capability.attr,
+	&dev_attr_events.attr,
+	NULL
+};
+
+static const struct attribute_group pvpanic_dev_group = {
+	.attrs = pvpanic_dev_attrs,
+};
+
+const struct attribute_group *pvpanic_dev_groups[] = {
+	&pvpanic_dev_group,
+	NULL
+};
+EXPORT_SYMBOL_GPL(pvpanic_dev_groups);
+
+int devm_pvpanic_probe(struct device *dev, void __iomem *base)
+{
+	struct pvpanic_instance *pi;
+
+	if (!base)
+		return -EINVAL;
+
+	pi = devm_kmalloc(dev, sizeof(*pi), GFP_KERNEL);
+	if (!pi)
+		return -ENOMEM;
+
+	pi->base = base;
+	pi->capability = PVPANIC_PANICKED | PVPANIC_CRASH_LOADED | PVPANIC_SHUTDOWN;
+
+	/* initlize capability by RDPT */
+	pi->capability &= ioread8(base);
+	pi->events = pi->capability;
+
+	pi->sys_off = NULL;
+	pvpanic_synchronize_sys_off_handler(dev, pi);
+
 	spin_lock(&pvpanic_lock);
 	list_add(&pi->list, &pvpanic_list);
 	spin_unlock(&pvpanic_lock);