xen: Split x86/debugger.h into common and arch specific parts

With all the non-CONFIG_CRASH_DEBUG functionality moved elsewhere, split
x86/debugger.h in two, with the stubs and explanation moved to xen/debugger.h.

In particular, this means that arches only need to provide an $arch/debugger.h
if they implement CONFIG_CRASH_DEBUG, and ARM's stub can be deleted.

Signed-off-by: Bobby Eshleman <bobby.eshleman@gmail.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Acked-by: Jan Beulich <jbeulich@suse.com>

xen/arch/arm/include/asm/debugger.h

@@ -1,15 +0,0 @@
-#ifndef __ARM_DEBUGGER_H__
-#define __ARM_DEBUGGER_H__
-
-#define debugger_trap_fatal(v, r) (0)
-#define debugger_trap_immediate() ((void) 0)
-
-#endif /* __ARM_DEBUGGER_H__ */
-/*
- * Local variables:
- * mode: C
- * c-file-style: "BSD"
- * c-basic-offset: 4
- * indent-tabs-mode: nil
- * End:
- */

xen/arch/x86/include/asm/debugger.h

@@ -1,30 +1,12 @@
 /* SPDX-License-Identifier: GPL-2.0 */
 /******************************************************************************
- * asm/debugger.h
- * 
- * Generic hooks into arch-dependent Xen.
- * 
- * Each debugger should define two functions here:
- * 
- * debugger_trap_fatal():
- *  Called when Xen is about to give up and crash. Typically you will use this
- *  hook to drop into a debug session. It can also be used to hook off
- *  deliberately caused traps (which you then handle and return non-zero).
+ * xen/arch/x86/include/asm/debugger.h
  *
- * debugger_trap_immediate():
- *  Called if we want to drop into a debugger now.  This is essentially the
- *  same as debugger_trap_fatal, except that we use the current register state
- *  rather than the state which was in effect when we took the trap.
- *  For example: if we're dying because of an unhandled exception, we call
- *  debugger_trap_fatal; if we're dying because of a panic() we call
- *  debugger_trap_immediate().
+ * x86-specific debugger hooks.
  */
-
 #ifndef __X86_DEBUGGER_H__
 #define __X86_DEBUGGER_H__
 
-#ifdef CONFIG_CRASH_DEBUG
-
 #include <xen/gdbstub.h>
 #include <xen/stdbool.h>
 
@@ -45,16 +27,4 @@ static inline bool debugger_trap_fatal(
 /* Int3 is a trivial way to gather cpu_user_regs context. */
 #define debugger_trap_immediate() __asm__ __volatile__ ( "int3" )
 
-#else
-
-static inline bool debugger_trap_fatal(
-    unsigned int vector, struct cpu_user_regs *regs)
-{
-    return false;
-}
-
-#define debugger_trap_immediate() ((void)0)
-
-#endif
-
 #endif /* __X86_DEBUGGER_H__ */

xen/arch/x86/traps.c

@@ -36,6 +36,7 @@
 #include <xen/shutdown.h>
 #include <xen/guest_access.h>
 #include <asm/regs.h>
+#include <xen/debugger.h>
 #include <xen/delay.h>
 #include <xen/event.h>
 #include <xen/spinlock.h>
@@ -64,7 +65,6 @@
 #include <asm/uaccess.h>
 #include <asm/i387.h>
 #include <asm/xstate.h>
-#include <asm/debugger.h>
 #include <asm/msr.h>
 #include <asm/nmi.h>
 #include <asm/xenoprof.h>

xen/common/keyhandler.c

@@ -3,6 +3,7 @@
  */
 
 #include <asm/regs.h>
+#include <xen/debugger.h>
 #include <xen/delay.h>
 #include <xen/keyhandler.h>
 #include <xen/param.h>
@@ -20,7 +21,6 @@
 #include <xen/mm.h>
 #include <xen/watchdog.h>
 #include <xen/init.h>
-#include <asm/debugger.h>
 #include <asm/div64.h>
 
 static unsigned char keypress_key;

xen/common/shutdown.c

@@ -2,13 +2,13 @@
 #include <xen/lib.h>
 #include <xen/param.h>
 #include <xen/sched.h>
+#include <xen/debugger.h>
 #include <xen/domain.h>
 #include <xen/delay.h>
 #include <xen/watchdog.h>
 #include <xen/shutdown.h>
 #include <xen/console.h>
 #include <xen/kexec.h>
-#include <asm/debugger.h>
 #include <public/sched.h>
 
 /* opt_noreboot: If true, machine will need manual reset on error. */

xen/drivers/char/console.c

@@ -15,6 +15,7 @@
 #include <xen/init.h>
 #include <xen/event.h>
 #include <xen/console.h>
+#include <xen/debugger.h>
 #include <xen/param.h>
 #include <xen/serial.h>
 #include <xen/softirq.h>
@@ -26,7 +27,6 @@
 #include <xen/kexec.h>
 #include <xen/ctype.h>
 #include <xen/warning.h>
-#include <asm/debugger.h>
 #include <asm/div64.h>
 #include <xen/hypercall.h> /* for do_console_io */
 #include <xen/early_printk.h>

xen/include/xen/debugger.h

@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/******************************************************************************
+ * Arch specific debuggers should implement:
+ *
+ * debugger_trap_fatal():
+ *  Called when Xen is about to give up and crash. Typically you will use this
+ *  hook to drop into a debug session. It can also be used to hook off
+ *  deliberately caused traps (which you then handle and return non-zero).
+ *
+ * debugger_trap_immediate():
+ *  Called if we want to drop into a debugger now.  This is essentially the
+ *  same as debugger_trap_fatal, except that we use the current register state
+ *  rather than the state which was in effect when we took the trap.
+ *  For example: if we're dying because of an unhandled exception, we call
+ *  debugger_trap_fatal; if we're dying because of a panic() we call
+ *  debugger_trap_immediate().
+ */
+
+#ifndef __XEN_DEBUGGER_H__
+#define __XEN_DEBUGGER_H__
+
+#ifdef CONFIG_CRASH_DEBUG
+
+#include <asm/debugger.h>
+
+#else
+
+#include <xen/stdbool.h>
+
+struct cpu_user_regs;
+
+static inline bool debugger_trap_fatal(
+    unsigned int vector, const struct cpu_user_regs *regs)
+{
+    return false;
+}
+
+static inline void debugger_trap_immediate(void)
+{
+}
+
+#endif /* CONFIG_CRASH_DEBUG */
+
+#endif /* __XEN_DEBUGGER_H__ */