[PATCH] powerpc: fix os-term usage on kernel panic

[Linas Vepstas]

The rtas_os_term() routine was being called at the wrong time.
The actual rtas call "os-term" will not ever return, and so
calling it from the panic notifier is too early.  Instead,
call it from the machine_reset() call.

The patch splits the rtas_os_term() routine into two: one 
part to capture the kernel panic message, invoked during
the panic notifier, and another part that is invoked during 
machine_reset().

Prior to this patch, the os-term call was never being made,
because panic_timeout was always non-zero. Calling os-term 
helps keep the hypervisor happy! We have to keep the hypervisor
happy to avoid service, dump and error reporting problems.

Signed-off-by: Linas Vepstas <linas at austin.ibm.com>

----
One could make a strong argument to move all of this code 
from kernel/rtas.c to platforms/pseries/setup.c  I did not
do this, just so as to make the changes minimal.

 arch/powerpc/kernel/rtas.c             |   12 ++++++------
 arch/powerpc/platforms/pseries/setup.c |    3 ++-
 include/asm-powerpc/rtas.h             |    3 ++-
 3 files changed, 10 insertions(+), 8 deletions(-)

Index: linux-2.6.24-rc2-git4/arch/powerpc/kernel/rtas.c
===================================================================
--- linux-2.6.24-rc2-git4.orig/arch/powerpc/kernel/rtas.c	2007-11-19 18:58:53.000000000 -0600
+++ linux-2.6.24-rc2-git4/arch/powerpc/kernel/rtas.c	2007-11-19 19:01:10.000000000 -0600
@@ -631,18 +631,18 @@ void rtas_halt(void)
 /* Must be in the RMO region, so we place it here */
 static char rtas_os_term_buf[2048];
 
-void rtas_os_term(char *str)
+void rtas_panic_msg(char *str)
 {
-	int status;
+	snprintf(rtas_os_term_buf, 2048, "OS panic: %s", str);
+}
 
-	if (panic_timeout)
-		return;
+void rtas_os_term(void)
+{
+	int status;
 
 	if (RTAS_UNKNOWN_SERVICE == rtas_token("ibm,os-term"))
 		return;
 
-	snprintf(rtas_os_term_buf, 2048, "OS panic: %s", str);
-
 	do {
 		status = rtas_call(rtas_token("ibm,os-term"), 1, 1, NULL,
 				   __pa(rtas_os_term_buf));
Index: linux-2.6.24-rc2-git4/arch/powerpc/platforms/pseries/setup.c
===================================================================
--- linux-2.6.24-rc2-git4.orig/arch/powerpc/platforms/pseries/setup.c	2007-11-19 18:58:53.000000000 -0600
+++ linux-2.6.24-rc2-git4/arch/powerpc/platforms/pseries/setup.c	2007-11-19 19:01:10.000000000 -0600
@@ -507,7 +507,8 @@ define_machine(pseries) {
 	.restart		= rtas_restart,
 	.power_off		= pSeries_power_off,
 	.halt			= rtas_halt,
-	.panic			= rtas_os_term,
+	.panic			= rtas_panic_msg,
+	.machine_shutdown	= rtas_os_term,
 	.get_boot_time		= rtas_get_boot_time,
 	.get_rtc_time		= rtas_get_rtc_time,
 	.set_rtc_time		= rtas_set_rtc_time,
Index: linux-2.6.24-rc2-git4/include/asm-powerpc/rtas.h
===================================================================
--- linux-2.6.24-rc2-git4.orig/include/asm-powerpc/rtas.h	2007-11-19 18:58:53.000000000 -0600
+++ linux-2.6.24-rc2-git4/include/asm-powerpc/rtas.h	2007-11-19 19:01:10.000000000 -0600
@@ -164,7 +164,8 @@ extern int rtas_call(int token, int, int
 extern void rtas_restart(char *cmd);
 extern void rtas_power_off(void);
 extern void rtas_halt(void);
-extern void rtas_os_term(char *str);
+extern void rtas_panic_msg(char *str);
+extern void rtas_os_term(void);
 extern int rtas_get_sensor(int sensor, int index, int *state);
 extern int rtas_get_power_level(int powerdomain, int *level);
 extern int rtas_set_power_level(int powerdomain, int level, int *setlevel);