misc/pvpanic: split-up generic and platform dependent code

Split-up generic and platform dependent code in order to be able to re-use
generic event handling code in pvpanic PCI device driver in the next patches.

The code from pvpanic.c was split in two new files:
- pvpanic.c: generic code that handles pvpanic events
- pvpanic-mmio.c: platform/bus dependent code

Signed-off-by: Mihai Carabas <mihai.carabas@oracle.com>

drivers/misc/Kconfig

@@ -448,14 +448,6 @@ config MISC_RTSX
 	tristate
 	default MISC_RTSX_PCI || MISC_RTSX_USB
 
-config PVPANIC
-	tristate "pvpanic device support"
-	depends on HAS_IOMEM && (ACPI || OF)
-	help
-	  This driver provides support for the pvpanic device.  pvpanic is
-	  a paravirtualized device provided by QEMU; it lets a virtual machine
-	  (guest) communicate panic events to the host.
-
 config HISI_HIKEY_USB
 	tristate "USB GPIO Hub on HiSilicon Hikey 960/970 Platform"
 	depends on (OF && GPIOLIB) || COMPILE_TEST
@@ -481,4 +473,5 @@ source "drivers/misc/ocxl/Kconfig"
 source "drivers/misc/cardreader/Kconfig"
 source "drivers/misc/habanalabs/Kconfig"
 source "drivers/misc/uacce/Kconfig"
+source "drivers/misc/pvpanic/Kconfig"
 endmenu

drivers/misc/Makefile

@@ -52,7 +52,7 @@ obj-$(CONFIG_CXL_BASE)		+= cxl/
 obj-$(CONFIG_PCI_ENDPOINT_TEST)	+= pci_endpoint_test.o
 obj-$(CONFIG_OCXL)		+= ocxl/
 obj-y				+= cardreader/
-obj-$(CONFIG_PVPANIC)   	+= pvpanic.o
+obj-$(CONFIG_PVPANIC)   	+= pvpanic/
 obj-$(CONFIG_HABANA_AI)		+= habanalabs/
 obj-$(CONFIG_UACCE)		+= uacce/
 obj-$(CONFIG_XILINX_SDFEC)	+= xilinx_sdfec.o

drivers/misc/pvpanic/Kconfig

@@ -0,0 +1,19 @@
+# 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.

drivers/misc/pvpanic/Makefile

@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Pvpanic Makefile
+#
+# Copyright (C) 2021 Oracle.
+#
+obj-$(CONFIG_PVPANIC)		+= pvpanic.o
+obj-$(CONFIG_PVPANIC_MMIO)	+= pvpanic-mmio.o

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

@@ -1,12 +1,11 @@
 // SPDX-License-Identifier: GPL-2.0+
 /*
- *  Pvpanic Device Support
+ *  Pvpanic MMIO Device Support
  *
  *  Copyright (C) 2013 Fujitsu.
  *  Copyright (C) 2018 ZTE.
- */
-
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+ *  Copyright (C) 2021 Oracle.
+*/
 
 #include <linux/io.h>
 #include <linux/kernel.h>
@@ -17,42 +16,17 @@
 #include <linux/types.h>
 
 #include <uapi/misc/pvpanic.h>
-
-static void __iomem *base;
+#include "pvpanic.h"
 
 MODULE_AUTHOR("Hu Tao <hutao@cn.fujitsu.com>");
 MODULE_DESCRIPTION("pvpanic device driver");
 MODULE_LICENSE("GPL");
 
-static void
-pvpanic_send_event(unsigned int event)
-{
-	iowrite8(event, base);
-}
-
-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;
-}
-
-static struct notifier_block pvpanic_panic_nb = {
-	.notifier_call = pvpanic_panic_notify,
-	.priority = 1, /* let this called before broken drm_fb_helper */
-};
-
 static int pvpanic_mmio_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct resource *res;
+	void __iomem *base;
 
 	res = platform_get_mem_or_io(pdev, 0);
 	if (!res)
@@ -73,17 +47,15 @@ static int pvpanic_mmio_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
-	atomic_notifier_chain_register(&panic_notifier_list,
-				       &pvpanic_panic_nb);
+	pvpanic_probe(base);
 
 	return 0;
 }
 
 static int pvpanic_mmio_remove(struct platform_device *pdev)
 {
 
-	atomic_notifier_chain_unregister(&panic_notifier_list,
-					 &pvpanic_panic_nb);
+	pvpanic_remove();
 
 	return 0;
 }

drivers/misc/pvpanic/pvpanic.c

@@ -0,0 +1,62 @@
+// 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/types.h>
+
+#include <uapi/misc/pvpanic.h>
+
+static void __iomem *base;
+
+static void
+pvpanic_send_event(unsigned int event)
+{
+	iowrite8(event, base);
+}
+
+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;
+}
+
+static struct notifier_block pvpanic_panic_nb = {
+	.notifier_call = pvpanic_panic_notify,
+	.priority = 1, /* let this called before broken drm_fb_helper */
+};
+
+void pvpanic_probe(void __iomem *pbase)
+{
+	base = pbase;
+	atomic_notifier_chain_register(&panic_notifier_list,
+				       &pvpanic_panic_nb);
+}
+EXPORT_SYMBOL_GPL(pvpanic_probe);
+
+void pvpanic_remove(void)
+{
+
+	atomic_notifier_chain_unregister(&panic_notifier_list,
+					 &pvpanic_panic_nb);
+	base = NULL;
+}
+EXPORT_SYMBOL_GPL(pvpanic_remove);

drivers/misc/pvpanic/pvpanic.h

@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  Pvpanic Device Support
+ *
+ *  Copyright (C) 2021 Oracle.
+*/
+
+#ifndef PVPANIC_H_
+#define PVPANIC_H_
+
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+void pvpanic_probe(void __iomem *base);
+void pvpanic_remove(void);
+
+#endif /* PVPANIC_H_ */