| From aef40e87d866355ffd279ab21021de733242d0d5 Mon Sep 17 00:00:00 2001 |
| From: Michael Neuling <mikey@neuling.org> |
| Date: Wed, 28 Apr 2010 13:39:41 +0000 |
| Subject: powerpc/pseries: Only call start-cpu when a CPU is stopped |
| |
| From: Michael Neuling <mikey@neuling.org> |
| |
| commit aef40e87d866355ffd279ab21021de733242d0d5 upstream. |
| |
| Currently we always call start-cpu irrespective of if the CPU is |
| stopped or not. Unfortunatley on POWER7, firmware seems to not like |
| start-cpu being called when a cpu already been started. This was not |
| the case on POWER6 and earlier. |
| |
| This patch checks to see if the CPU is stopped or not via an |
| query-cpu-stopped-state call, and only calls start-cpu on CPUs which |
| are stopped. |
| |
| This fixes a bug with kexec on POWER7 on PHYP where only the primary |
| thread would make it to the second kernel. |
| |
| Reported-by: Ankita Garg <ankita@linux.vnet.ibm.com> |
| Signed-off-by: Michael Neuling <mikey@neuling.org> |
| Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
| |
| --- |
| arch/powerpc/platforms/pseries/smp.c | 6 ++++++ |
| 1 file changed, 6 insertions(+) |
| |
| --- a/arch/powerpc/platforms/pseries/smp.c |
| +++ b/arch/powerpc/platforms/pseries/smp.c |
| @@ -81,6 +81,12 @@ static inline int __devinit smp_startup_ |
| |
| pcpu = get_hard_smp_processor_id(lcpu); |
| |
| + /* Check to see if the CPU out of FW already for kexec */ |
| + if (smp_query_cpu_stopped(pcpu) == QCSS_NOT_STOPPED){ |
| + cpu_set(lcpu, of_spin_map); |
| + return 1; |
| + } |
| + |
| /* Fixup atomic count: it exited inside IRQ handler. */ |
| task_thread_info(paca[lcpu].__current)->preempt_count = 0; |
| |
