misc/pvpanic: deduplicate common code

pvpanic-mmio.c and pvpanic-pci.c share a lot of code.
Refactor it into pvpanic.c where it doesn't have to be kept in sync
manually and where the core logic can be understood more easily.

No functional change.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/r/20231011-pvpanic-cleanup-v2-1-4b21d56f779f@weissschuh.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 74 insertions, 2 deletions

diff --git a/drivers/misc/pvpanic/pvpanic.c b/drivers/misc/pvpanic/pvpanic.c
index 049a12006348..305b367e0ce3 100644
--- a/drivers/misc/pvpanic/pvpanic.c
+++ b/drivers/misc/pvpanic/pvpanic.c
@@ -7,6 +7,7 @@
  *  Copyright (C) 2021 Oracle.
  */
 
+#include <linux/device.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
 #include <linux/kexec.h>
@@ -26,6 +27,13 @@ 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 list_head list;
+};
+
 static struct list_head pvpanic_list;
 static spinlock_t pvpanic_lock;
 
@@ -81,11 +89,75 @@ static void pvpanic_remove(void *param)
 	spin_unlock(&pvpanic_lock);
 }
 
-int devm_pvpanic_probe(struct device *dev, struct pvpanic_instance *pi)
+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_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)
 {
-	if (!pi || !pi->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;
+
+	/* initlize capability by RDPT */
+	pi->capability &= ioread8(base);
+	pi->events = pi->capability;
+
 	spin_lock(&pvpanic_lock);
 	list_add(&pi->list, &pvpanic_list);
 	spin_unlock(&pvpanic_lock);