watchdog: Move watchdog from being x86 specific to common code

Augment watchdog_setup() to be able to possibly return an error, and introduce
watchdog_enabled() as a better alternative to knowing the architectures
internal details.

This patch does not change the x86 implementaion, beyond making it compile.

For header files, some includes of xen/nmi.h were only for the watchdog
functions, so are replaced rather than adding an extra include of
xen/watchdog.h

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Keir Fraser <keir@xen.org>

xen/arch/x86/nmi.c

@@ -410,7 +410,12 @@ void watchdog_enable(void)
     atomic_dec(&watchdog_disable_count);
 }
 
-void __init watchdog_setup(void)
+bool_t watchdog_enabled(void)
+{
+    return !atomic_read(&watchdog_disable_count);
+}
+
+int __init watchdog_setup(void)
 {
     unsigned int cpu;
 
@@ -423,6 +428,7 @@ void __init watchdog_setup(void)
     register_cpu_notifier(&cpu_nmi_nfb);
 
     watchdog_enable();
+    return 0;
 }
 
 void nmi_watchdog_tick(struct cpu_user_regs * regs)

xen/arch/x86/setup.c

@@ -26,6 +26,7 @@
 #include <xen/pfn.h>
 #include <xen/nodemask.h>
 #include <xen/tmem_xen.h> /* for opt_tmem only */
+#include <xen/watchdog.h>
 #include <public/version.h>
 #include <compat/platform.h>
 #include <compat/xen.h>

xen/arch/x86/shutdown.c

@@ -12,7 +12,7 @@
 #include <xen/delay.h>
 #include <xen/dmi.h>
 #include <xen/irq.h>
-#include <xen/nmi.h>
+#include <xen/watchdog.h>
 #include <xen/console.h>
 #include <xen/shutdown.h>
 #include <xen/acpi.h>

xen/arch/x86/traps.c

@@ -49,6 +49,7 @@
 #include <xen/kexec.h>
 #include <xen/trace.h>
 #include <xen/paging.h>
+#include <xen/watchdog.h>
 #include <asm/system.h>
 #include <asm/io.h>
 #include <asm/atomic.h>

xen/arch/x86/x86_64/traps.c

@@ -13,6 +13,7 @@
 #include <xen/shutdown.h>
 #include <xen/nmi.h>
 #include <xen/guest_access.h>
+#include <xen/watchdog.h>
 #include <asm/current.h>
 #include <asm/flushtlb.h>
 #include <asm/traps.h>

xen/common/kexec.c

@@ -12,7 +12,7 @@
 #include <xen/ctype.h>
 #include <xen/errno.h>
 #include <xen/guest_access.h>
-#include <xen/nmi.h>
+#include <xen/watchdog.h>
 #include <xen/sched.h>
 #include <xen/types.h>
 #include <xen/hypercall.h>

xen/common/keyhandler.c

@@ -16,7 +16,7 @@
 #include <xen/ctype.h>
 #include <xen/perfc.h>
 #include <xen/mm.h>
-#include <xen/nmi.h>
+#include <xen/watchdog.h>
 #include <xen/init.h>
 #include <asm/debugger.h>
 #include <asm/div64.h>

xen/common/shutdown.c

@@ -4,7 +4,7 @@
 #include <xen/sched.h>
 #include <xen/domain.h>
 #include <xen/delay.h>
-#include <xen/nmi.h>
+#include <xen/watchdog.h>
 #include <xen/shutdown.h>
 #include <xen/console.h>
 #ifdef CONFIG_KEXEC

xen/drivers/char/console.c

@@ -20,7 +20,7 @@
 #include <xen/keyhandler.h>
 #include <xen/delay.h>
 #include <xen/guest_access.h>
-#include <xen/nmi.h>
+#include <xen/watchdog.h>
 #include <xen/shutdown.h>
 #include <xen/video.h>
 #include <xen/kexec.h>

xen/include/asm-x86/config.h

@@ -49,6 +49,7 @@
 
 #define CONFIG_XENOPROF 1
 #define CONFIG_KEXEC 1
+#define CONFIG_WATCHDOG 1
 
 #define HZ 100
 

xen/include/asm-x86/nmi.h

@@ -41,8 +41,4 @@ long register_guest_nmi_callback(unsigned long address);
  */
 long unregister_guest_nmi_callback(void);
 
-void watchdog_disable(void);
-void watchdog_enable(void);
-void watchdog_setup(void);
-
 #endif /* ASM_NMI_H */

xen/include/xen/watchdog.h

@@ -0,0 +1,35 @@
+/******************************************************************************
+ * watchdog.h
+ *
+ * Common watchdog code
+ */
+
+#ifndef __XEN_WATCHDOG_H__
+#define __XEN_WATCHDOG_H__
+
+#include <xen/types.h>
+
+#ifdef CONFIG_WATCHDOG
+
+/* Try to set up a watchdog. */
+int watchdog_setup(void);
+
+/* Enable the watchdog. */
+void watchdog_enable(void);
+
+/* Disable the watchdog. */
+void watchdog_disable(void);
+
+/* Is the watchdog currently enabled. */
+bool_t watchdog_enabled(void);
+
+#else
+
+#define watchdog_setup() ((void)0)
+#define watchdog_enable() ((void)0)
+#define watchdog_disable() ((void)0)
+#define watchdog_enabled() ((void)0)
+
+#endif
+
+#endif /* __XEN_WATCHDOG_H__ */