[v3,32/45] blackfin/smp: Use get/put_online_cpus_atomic() to prevent CPU offline

Message ID 20130627195801.29830.77286.stgit@srivatsabhat.in.ibm.com
State Not Applicable
Headers show

Commit Message

Srivatsa S. Bhat June 27, 2013, 7:58 p.m.
Once stop_machine() is gone from the CPU offline path, we won't be able
to depend on disabling preemption to prevent CPUs from going offline
from under us.

Use the get/put_online_cpus_atomic() APIs to prevent CPUs from going
offline, while invoking from atomic context.

Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Bob Liu <lliubbo@gmail.com>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: uclinux-dist-devel@blackfin.uclinux.org
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>

 arch/blackfin/mach-common/smp.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)


diff --git a/arch/blackfin/mach-common/smp.c b/arch/blackfin/mach-common/smp.c
index 1bc2ce6..11496cd 100644
--- a/arch/blackfin/mach-common/smp.c
+++ b/arch/blackfin/mach-common/smp.c
@@ -238,13 +238,13 @@  void smp_send_stop(void)
 	cpumask_t callmap;
-	preempt_disable();
+	get_online_cpus_atomic();
 	cpumask_copy(&callmap, cpu_online_mask);
 	cpumask_clear_cpu(smp_processor_id(), &callmap);
 	if (!cpumask_empty(&callmap))
 		send_ipi(&callmap, BFIN_IPI_CPU_STOP);
-	preempt_enable();
+	put_online_cpus_atomic();