[POWERPC] Allow xmon to build on legacy iSeries

xmon still does not run on iSeries, but this allows us to build a combined
kernel that includes it.
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

arch/powerpc/Kconfig.debug

@@ -77,7 +77,7 @@ config KGDB_CONSOLE
 
 config XMON
 	bool "Include xmon kernel debugger"
-	depends on DEBUGGER && !PPC_ISERIES
+	depends on DEBUGGER
 	help
 	  Include in-kernel hooks for the xmon kernel monitor/debugger.
 	  Unless you are intending to debug the kernel, say N here.

arch/powerpc/xmon/xmon.c

@@ -44,6 +44,7 @@
 #ifdef CONFIG_PPC64
 #include <asm/hvcall.h>
 #include <asm/paca.h>
+#include <asm/iseries/it_lp_reg_save.h>
 #endif
 
 #include "nonstdio.h"
@@ -2580,6 +2581,10 @@ void dump_segments(void)
 
 void xmon_init(int enable)
 {
+#ifdef CONFIG_PPC_ISERIES
+	if (firmware_has_feature(FW_FEATURE_ISERIES))
+		return;
+#endif
 	if (enable) {
 		__debugger = xmon;
 		__debugger_ipi = xmon_ipi;
@@ -2617,6 +2622,10 @@ static struct sysrq_key_op sysrq_xmon_op =
 
 static int __init setup_xmon_sysrq(void)
 {
+#ifdef CONFIG_PPC_ISERIES
+	if (firmware_has_feature(FW_FEATURE_ISERIES))
+		return 0;
+#endif
 	register_sysrq_key('x', &sysrq_xmon_op);
 	return 0;
 }