powerpc: Merge xmon

The merged version follows the ppc64 version pretty closely mostly,
and in fact ARCH=ppc64 now uses the arch/powerpc/xmon version.
The main difference for ppc64 is that the 'p' command to call
show_state (which was always pretty dodgy) has been replaced by
the ppc32 'p' command, which calls a given procedure (so in fact
the old 'p' command behaviour can be achieved with 'p $show_state').

Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/kernel/head_32.S

@@ -271,6 +271,9 @@ __secondary_hold_acknowledge:
 	li	r10,MSR_KERNEL & ~(MSR_IR|MSR_DR); /* can take exceptions */ \
 	MTMSRD(r10);			/* (except for mach check in rtas) */ \
 	stw	r0,GPR0(r11);	\
+	lis	r10,0x7265;		/* put exception frame marker */ \
+	addi	r10,r10,0x6773;	\
+	stw	r10,8(r11);	\
 	SAVE_4GPRS(3, r11);	\
 	SAVE_2GPRS(7, r11)
 

arch/powerpc/kernel/ppc_ksyms.c

@@ -44,7 +44,6 @@
 #include <asm/cputable.h>
 #include <asm/btext.h>
 #include <asm/div64.h>
-#include <asm/xmon.h>
 
 #ifdef  CONFIG_8xx
 #include <asm/commproc.h>
@@ -238,10 +237,6 @@ EXPORT_SYMBOL(console_drivers);
 EXPORT_SYMBOL(cacheable_memcpy);
 #endif
 
-#ifdef CONFIG_XMON
-EXPORT_SYMBOL(xmon);
-EXPORT_SYMBOL(xmon_printf);
-#endif
 EXPORT_SYMBOL(__up);
 EXPORT_SYMBOL(__down);
 EXPORT_SYMBOL(__down_interruptible);

arch/powerpc/kernel/setup_32.c

@@ -302,8 +302,10 @@ void __init setup_arch(char **cmdline_p)
 
 #ifdef CONFIG_XMON
 	xmon_map_scc();
-	if (strstr(cmd_line, "xmon"))
-		xmon(NULL);
+	if (strstr(cmd_line, "xmon")) {
+		xmon_init(1);
+		debugger(NULL);
+	}
 #endif /* CONFIG_XMON */
 	if ( ppc_md.progress ) ppc_md.progress("setup_arch: enter", 0x3eab);
 

arch/powerpc/kernel/setup_64.c

@@ -59,6 +59,7 @@
 #include <asm/iSeries/ItLpNaca.h>
 #include <asm/firmware.h>
 #include <asm/systemcfg.h>
+#include <asm/xmon.h>
 
 #ifdef DEBUG
 #define DBG(fmt...) udbg_printf(fmt)