Once stop_machine() is gone from the CPU offline path, we won't be able to
depend on preempt_disable() or local_irq_disable() 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@xxxxxxxxxx>
Cc: Bob Liu <lliubbo@xxxxxxxxx>
Cc: Steven Miao <realmz6@xxxxxxxxx>
Cc: uclinux-dist-devel@xxxxxxxxxxxxxxxxxxxx
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@xxxxxxxxxxxxxxxxxx>
---
arch/blackfin/mach-common/smp.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/arch/blackfin/mach-common/smp.c b/arch/blackfin/mach-common/smp.c
index bb61ae4..6cc6d7a 100644
--- a/arch/blackfin/mach-common/smp.c
+++ b/arch/blackfin/mach-common/smp.c
@@ -194,6 +194,7 @@ void send_ipi(const struct cpumask *cpumask, enum ipi_message_type msg)
struct ipi_data *bfin_ipi_data;
unsigned long flags;
+ get_online_cpus_atomic();
local_irq_save(flags);
smp_mb();
for_each_cpu(cpu, cpumask) {
@@ -205,6 +206,7 @@ void send_ipi(const struct cpumask *cpumask, enum ipi_message_type msg)
}
local_irq_restore(flags);
+ put_online_cpus_atomic();
}
void arch_send_call_function_single_ipi(int cpu)
@@ -238,13 +240,13 @@ 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();
return;
}
--
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