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

[Will Schmidt]

(resending with the proper "from" addr this time). 


I'm seeing some funky behavior on power5/power6 partitions with this
patch.    A "/sbin/reboot" is now behaving much more like a
"/sbin/halt".

Anybody else seeing this, or is it time for me to call an exorcist for
my boxes? 

-Will

On Mon, 2007-11-19 at 19:28 -0600, Linas Vepstas wrote:
> 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);
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