[PATCH 4/5] Only enable cpu hotplug via RTAS if the required firmware support is found
Michael Ellerman
michael at ellerman.id.au
Tue Dec 5 17:52:38 EST 2006
To support cpu hotplug on pseries we require two RTAS tokens, the cpu
hotplug machinery should only be wired up if these tokens are found in
the device tree.
Signed-off-by: Michael Ellerman <michael at ellerman.id.au>
---
arch/powerpc/platforms/pseries/hotplug-cpu.c | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)
Index: powerpc/arch/powerpc/platforms/pseries/hotplug-cpu.c
===================================================================
--- powerpc.orig/arch/powerpc/platforms/pseries/hotplug-cpu.c
+++ powerpc/arch/powerpc/platforms/pseries/hotplug-cpu.c
@@ -64,6 +64,8 @@ static void pSeries_mach_cpu_die(void)
for(;;);
}
+static int qcss_tok; /* query-cpu-stopped-state token */
+
/* Get state of physical CPU.
* Return codes:
* 0 - The processor is in the RTAS stopped state
@@ -74,12 +76,8 @@ static void pSeries_mach_cpu_die(void)
*/
static int query_cpu_stopped(unsigned int pcpu)
{
- int cpu_status;
- int status, qcss_tok;
+ int cpu_status, status;
- qcss_tok = rtas_token("query-cpu-stopped-state");
- if (qcss_tok == RTAS_UNKNOWN_SERVICE)
- return -1;
status = rtas_call(qcss_tok, 1, 2, &cpu_status, pcpu);
if (status != 0) {
printk(KERN_ERR
@@ -254,9 +252,16 @@ static struct notifier_block pSeries_smp
static int __init pseries_cpu_hotplug_init(void)
{
rtas_stop_self_args.token = rtas_token("stop-self");
+ qcss_tok = rtas_token("query-cpu-stopped-state");
- ppc_md.cpu_die = pSeries_mach_cpu_die;
+ if (rtas_stop_self_args.token == RTAS_UNKNOWN_SERVICE ||
+ qcss_tok == RTAS_UNKNOWN_SERVICE) {
+ printk(KERN_INFO "CPU Hotplug not supported by firmware "
+ "- disabling.\n");
+ return 0;
+ }
+ ppc_md.cpu_die = pSeries_mach_cpu_die;
smp_ops->cpu_disable = pSeries_cpu_disable;
smp_ops->cpu_die = pSeries_cpu_die;
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