[PATCH] ppc64: allow xmon=off

If both CONFIG_XMON and CONFIG_XMON_DEFAULT is enabled in the .config,
there is no way to disable xmon again. setup_system calls first xmon_init,
later parse_early_param. So a new 'xmon=off' cmdline option will do the right
thing.

Signed-off-by: Olaf Hering <olh@suse.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>

4 files changed, 26 insertions, 14 deletions

diff --git a/arch/ppc64/kernel/setup.c b/arch/ppc64/kernel/setup.c
index e9c24d2dbd91..b3ef8df12982 100644
--- a/arch/ppc64/kernel/setup.c
+++ b/arch/ppc64/kernel/setup.c
@@ -627,7 +627,7 @@ void __init setup_system(void)
          * Initialize xmon
          */
 #ifdef CONFIG_XMON_DEFAULT
-        xmon_init();
+        xmon_init(1);
 #endif
         /*
          * Register early console
@@ -1343,11 +1343,13 @@ static int __init early_xmon(char *p)
         /* ensure xmon is enabled */
         if (p) {
                 if (strncmp(p, "on", 2) == 0)
-                        xmon_init();
+                        xmon_init(1);
+                if (strncmp(p, "off", 3) == 0)
+                        xmon_init(0);
                 if (strncmp(p, "early", 5) != 0)
                         return 0;
         }
-        xmon_init();
+        xmon_init(1);
         debugger(NULL);
 
         return 0;
diff --git a/arch/ppc64/xmon/start.c b/arch/ppc64/xmon/start.c
index a9265bcc79b2..f86b584acd76 100644
--- a/arch/ppc64/xmon/start.c
+++ b/arch/ppc64/xmon/start.c
@@ -27,7 +27,7 @@ static void sysrq_handle_xmon(int key, struct pt_regs *pt_regs,
                               struct tty_struct *tty) 
 {
         /* ensure xmon is enabled */
-        xmon_init();
+        xmon_init(1);
         debugger(pt_regs);
 }
 
diff --git a/arch/ppc64/xmon/xmon.c b/arch/ppc64/xmon/xmon.c
index 05539439e6bc..45908b10acd3 100644
--- a/arch/ppc64/xmon/xmon.c
+++ b/arch/ppc64/xmon/xmon.c
@@ -2496,15 +2496,25 @@ static void dump_stab(void)
         }
 }
 
-void xmon_init(void)
-{
-        __debugger = xmon;
-        __debugger_ipi = xmon_ipi;
-        __debugger_bpt = xmon_bpt;
-        __debugger_sstep = xmon_sstep;
-        __debugger_iabr_match = xmon_iabr_match;
-        __debugger_dabr_match = xmon_dabr_match;
-        __debugger_fault_handler = xmon_fault_handler;
+void xmon_init(int enable)
+{
+        if (enable) {
+                __debugger = xmon;
+                __debugger_ipi = xmon_ipi;
+                __debugger_bpt = xmon_bpt;
+                __debugger_sstep = xmon_sstep;
+                __debugger_iabr_match = xmon_iabr_match;
+                __debugger_dabr_match = xmon_dabr_match;
+                __debugger_fault_handler = xmon_fault_handler;
+        } else {
+                __debugger = NULL;
+                __debugger_ipi = NULL;
+                __debugger_bpt = NULL;
+                __debugger_sstep = NULL;
+                __debugger_iabr_match = NULL;
+                __debugger_dabr_match = NULL;
+                __debugger_fault_handler = NULL;
+        }
 }
 
 void dump_segments(void)
diff --git a/include/asm-ppc64/system.h b/include/asm-ppc64/system.h
index 4104a5dedbaa..b9e1835351e9 100644
--- a/include/asm-ppc64/system.h
+++ b/include/asm-ppc64/system.h
@@ -88,7 +88,7 @@ DEBUGGER_BOILERPLATE(debugger_dabr_match)
 DEBUGGER_BOILERPLATE(debugger_fault_handler)
 
 #ifdef CONFIG_XMON
-extern void xmon_init(void);
+extern void xmon_init(int enable);
 #endif
 
 #else