[PATCH] powerpc: Early debugging support for iSeries

Connect iSeries up to the standard early debugging infrastructure.

To actually use this you need to enable the iSeries early debugging
in setup_64.c. Then after the messages are logged hit Ctrl-x Ctrl-x on
your console to dump the Hypervisor console buffer.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/kernel/setup_64.c

@@ -75,22 +75,26 @@
  * but your kernel will not boot on anything else if you do so
  */
 
-/* This one is for use on LPAR machines that support an HVC console
- * on vterm 0
- */
+/* For use on LPAR machines that support an HVC console on vterm 0 */
 extern void udbg_init_debug_lpar(void);
-/* This one is for use on Apple G5 machines
- */
+
+/* This one is for use on Apple G5 machines */
 extern void udbg_init_pmac_realmode(void);
+
 /* That's RTAS panel debug */
 extern void call_rtas_display_status_delay(unsigned char c);
+
 /* Here's maple real mode debug */
 extern void udbg_init_maple_realmode(void);
 
+/* For iSeries - hit Ctrl-x Ctrl-x to see the output */
+extern void udbg_init_iseries(void);
+
 #define EARLY_DEBUG_INIT() do {} while(0)
 
 #if 0
 #define EARLY_DEBUG_INIT() udbg_init_debug_lpar()
+#define EARLY_DEBUG_INIT() udbg_init_iseries()
 #define EARLY_DEBUG_INIT() udbg_init_maple_realmode()
 #define EARLY_DEBUG_INIT() udbg_init_pmac_realmode()
 #define EARLY_DEBUG_INIT()						\

arch/powerpc/platforms/iseries/setup.c

@@ -52,6 +52,7 @@
 #include <asm/iseries/mf.h>
 #include <asm/iseries/hv_lp_event.h>
 #include <asm/iseries/lpar_map.h>
+#include <asm/udbg.h>
 
 #include "naca.h"
 #include "setup.h"
@@ -62,10 +63,8 @@
 #include "call_sm.h"
 #include "call_hpt.h"
 
-extern void hvlog(char *fmt, ...);
-
 #ifdef DEBUG
-#define DBG(fmt...) hvlog(fmt)
+#define DBG(fmt...) udbg_printf(fmt)
 #else
 #define DBG(fmt...)
 #endif
@@ -984,3 +983,16 @@ static int __init early_parsemem(char *p)
 	return 0;
 }
 early_param("mem", early_parsemem);
+
+static void hvputc(char c)
+{
+	if (c == '\n')
+		hvputc('\r');
+
+	HvCall_writeLogBuffer(&c, 1);
+}
+
+void __init udbg_init_iseries(void)
+{
+	udbg_putc = hvputc;
+}

drivers/char/viocons.c

@@ -131,7 +131,7 @@ static void initDataEvent(struct viocharlpevent *viochar, HvLpIndex lp);
 
 static struct tty_driver *viotty_driver;
 
-void hvlog(char *fmt, ...)
+static void hvlog(char *fmt, ...)
 {
 	int i;
 	unsigned long flags;
@@ -147,7 +147,7 @@ void hvlog(char *fmt, ...)
 	spin_unlock_irqrestore(&consoleloglock, flags);
 }
 
-void hvlogOutput(const char *buf, int count)
+static void hvlogOutput(const char *buf, int count)
 {
 	unsigned long flags;
 	int begin;