[POWERPC] Fix xmon=off and cleanup xmon initialisation

My patch to make the early xmon logic work with earlier early param
parsing (480f6f35a149802a94ad5c1a2673ed6ec8d2c158) breaks xmon=off.

No one does this obviously as xmon rocks, but it should really work
as documented.

While fixing that it struck me that we could move the xmon param
handling into xmon.c, and also consolidate the
xmon_init()/do_early_xmon logic into xmon_setup(). This means
xmon=early drops into xmon a little earlier on 32-bit, but it
seems to work just fine.

Tested on PSERIES and CLASSIC32.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>

3 files changed, 6 insertions, 39 deletions

diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index 0af3fc1bdcc..89cfaf49d3d 100644
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -442,31 +442,6 @@ void __init smp_setup_cpu_maps(void)
 }
 #endif /* CONFIG_SMP */
 
-int __initdata do_early_xmon;
-#ifdef CONFIG_XMON
-extern int xmon_no_auto_backtrace;
-
-static int __init early_xmon(char *p)
-{
-	/* ensure xmon is enabled */
-	if (p) {
-		if (strncmp(p, "on", 2) == 0)
-			xmon_init(1);
-		if (strncmp(p, "off", 3) == 0)
-			xmon_init(0);
-		if (strncmp(p, "nobt", 4) == 0)
-			xmon_no_auto_backtrace = 1;
-		if (strncmp(p, "early", 5) != 0)
-			return 0;
-	}
-	xmon_init(1);
-	do_early_xmon = 1;
-
-	return 0;
-}
-early_param("xmon", early_xmon);
-#endif
-
 static __init int add_pcspkr(void)
 {
 	struct device_node *np;
diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c
index 79a17795d17..191d0ab0922 100644
--- a/arch/powerpc/kernel/setup_32.c
+++ b/arch/powerpc/kernel/setup_32.c
@@ -238,12 +238,11 @@ void __init setup_arch(char **cmdline_p)
 
 	smp_setup_cpu_maps();
 
-#ifdef CONFIG_XMON_DEFAULT
-	xmon_init(1);
-#endif
 	/* Register early console */
 	register_early_udbg_console();
 
+	xmon_setup();
+
 #if defined(CONFIG_KGDB)
 	if (ppc_md.kgdb_map_scc)
 		ppc_md.kgdb_map_scc();
@@ -280,9 +279,6 @@ void __init setup_arch(char **cmdline_p)
 	init_mm.end_data = (unsigned long) _edata;
 	init_mm.brk = klimit;
 
-	if (do_early_xmon)
-		debugger(NULL);
-
 	/* set up the bootmem stuff with available memory */
 	do_init_bootmem();
 	if ( ppc_md.progress ) ppc_md.progress("setup_arch: bootmem", 0x3eab);
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index cda2dbe70a7..4b2e32eab9d 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -391,18 +391,14 @@ void __init setup_system(void)
 	find_legacy_serial_ports();
 
 	/*
-	 * Initialize xmon
-	 */
-#ifdef CONFIG_XMON_DEFAULT
-	xmon_init(1);
-#endif
-	/*
 	 * Register early console
 	 */
 	register_early_udbg_console();
 
-	if (do_early_xmon)
-		debugger(NULL);
+	/*
+	 * Initialize xmon
+	 */
+	xmon_setup();
 
 	check_smt_enabled();
 	smp_setup_cpu_maps();