Linux-libre 4.2-gnu

1 files changed, 6 insertions, 39 deletions

diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index 263b0e1ad..fd643d8c4 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -41,8 +41,7 @@ struct cpu_stopper {
 };
 
 static DEFINE_PER_CPU(struct cpu_stopper, cpu_stopper);
-DEFINE_PER_CPU(struct task_struct *, cpu_stopper_task);
-
+static DEFINE_PER_CPU(struct task_struct *, cpu_stopper_task);
 static bool stop_machine_initialized = false;
 
 /*
@@ -212,25 +211,6 @@ static int multi_cpu_stop(void *data)
 	return err;
 }
 
-struct irq_cpu_stop_queue_work_info {
-	int cpu1;
-	int cpu2;
-	struct cpu_stop_work *work1;
-	struct cpu_stop_work *work2;
-};
-
-/*
- * This function is always run with irqs and preemption disabled.
- * This guarantees that both work1 and work2 get queued, before
- * our local migrate thread gets the chance to preempt us.
- */
-static void irq_cpu_stop_queue_work(void *arg)
-{
-	struct irq_cpu_stop_queue_work_info *info = arg;
-	cpu_stop_queue_work(info->cpu1, info->work1);
-	cpu_stop_queue_work(info->cpu2, info->work2);
-}
-
 /**
  * stop_two_cpus - stops two cpus
  * @cpu1: the cpu to stop
@@ -246,7 +226,6 @@ int stop_two_cpus(unsigned int cpu1, unsigned int cpu2, cpu_stop_fn_t fn, void *
 {
 	struct cpu_stop_done done;
 	struct cpu_stop_work work1, work2;
-	struct irq_cpu_stop_queue_work_info call_args;
 	struct multi_stop_data msdata;
 
 	preempt_disable();
@@ -263,13 +242,6 @@ int stop_two_cpus(unsigned int cpu1, unsigned int cpu2, cpu_stop_fn_t fn, void *
 		.done = &done
 	};
 
-	call_args = (struct irq_cpu_stop_queue_work_info){
-		.cpu1 = cpu1,
-		.cpu2 = cpu2,
-		.work1 = &work1,
-		.work2 = &work2,
-	};
-
 	cpu_stop_init_done(&done, 2);
 	set_state(&msdata, MULTI_STOP_PREPARE);
 
@@ -286,16 +258,11 @@ int stop_two_cpus(unsigned int cpu1, unsigned int cpu2, cpu_stop_fn_t fn, void *
 		return -ENOENT;
 	}
 
-	lg_local_lock(&stop_cpus_lock);
-	/*
-	 * Queuing needs to be done by the lowest numbered CPU, to ensure
-	 * that works are always queued in the same order on every CPU.
-	 * This prevents deadlocks.
-	 */
-	smp_call_function_single(min(cpu1, cpu2),
-				 &irq_cpu_stop_queue_work,
-				 &call_args, 1);
-	lg_local_unlock(&stop_cpus_lock);
+	lg_double_lock(&stop_cpus_lock, cpu1, cpu2);
+	cpu_stop_queue_work(cpu1, &work1);
+	cpu_stop_queue_work(cpu2, &work2);
+	lg_double_unlock(&stop_cpus_lock, cpu1, cpu2);
+
 	preempt_enable();
 
 	wait_for_completion(&done.completion);