arm64: use the new *_relaxed macros for lower power usage

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: Joe Maples <joe@frap129.org>
Signed-off-by: Mister Oyster <oysterized@gmail.com>

6 files changed, 20 insertions, 18 deletions

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 66a980fcf..d384b9d21 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -973,7 +973,7 @@ static void cpuset_change_task_nodemask(struct task_struct *tsk,
 	 * Allow tasks that have access to memory reserves because they have
 	 * been OOM killed to get memory anywhere.
 	 */
-	if (unlikely(test_thread_flag(TIF_MEMDIE)))
+	if (unlikely(test_thread_flag_relaxed(TIF_MEMDIE)))
 		return;
 	if (current->flags & PF_EXITING) /* Let dying task have memory */
 		return;
@@ -2451,7 +2451,7 @@ int __cpuset_node_allowed_softwall(int node, gfp_t gfp_mask)
 	 * Allow tasks that have access to memory reserves because they have
 	 * been OOM killed to get memory anywhere.
 	 */
-	if (unlikely(test_thread_flag(TIF_MEMDIE)))
+	if (unlikely(test_thread_flag_relaxed(TIF_MEMDIE)))
 		return 1;
 	if (gfp_mask & __GFP_HARDWALL)	/* If hardwall request, stop here */
 		return 0;
@@ -2504,7 +2504,7 @@ int __cpuset_node_allowed_hardwall(int node, gfp_t gfp_mask)
 	 * Allow tasks that have access to memory reserves because they have
 	 * been OOM killed to get memory anywhere.
 	 */
-	if (unlikely(test_thread_flag(TIF_MEMDIE)))
+	if (unlikely(test_thread_flag_relaxed(TIF_MEMDIE)))
 		return 1;
 	return 0;
 }
diff --git a/kernel/freezer.c b/kernel/freezer.c
index 4ada72f5f..adf590772 100644
--- a/kernel/freezer.c
+++ b/kernel/freezer.c
@@ -42,7 +42,7 @@ bool freezing_slow_path(struct task_struct *p)
 	if (p->flags & PF_NOFREEZE)
 		return false;
 
-	if (test_thread_flag(TIF_MEMDIE))
+	if (test_thread_flag_relaxed(TIF_MEMDIE))
 		return false;
 
 	if (pm_nosig_freezing || cgroup_freezing(p))
diff --git a/kernel/irq_work.c b/kernel/irq_work.c
index 55fcce606..4bcbeafc6 100644
--- a/kernel/irq_work.c
+++ b/kernel/irq_work.c
@@ -91,7 +91,7 @@ bool irq_work_needs_cpu(void)
 	struct llist_head *this_list;
 
 	this_list = &__get_cpu_var(irq_work_list);
-	if (llist_empty(this_list))
+	if (llist_empty_relaxed(this_list))
 		return false;
 
 	/* All work should have been flushed before going offline */
@@ -116,7 +116,7 @@ static void __irq_work_run(void)
 	barrier();
 
 	this_list = &__get_cpu_var(irq_work_list);
-	if (llist_empty(this_list))
+	if (llist_empty_relaxed(this_list))
 		return;
 
 	BUG_ON(!irqs_disabled());
diff --git a/kernel/mutex.c b/kernel/mutex.c
index d77807b1e..9d953374e 100644
--- a/kernel/mutex.c
+++ b/kernel/mutex.c
@@ -143,8 +143,8 @@ void mspin_lock(struct mspin_node **lock, struct mspin_node *node)
 	ACCESS_ONCE(prev->next) = node;
 	smp_wmb();
 	/* Wait until the lock holder passes the lock down */
-	while (!ACCESS_ONCE(node->locked))
-		arch_mutex_cpu_relax();
+	while (!cpu_relaxed_read(&(node->locked)))
+		cpu_read_relax();
 }
 
 static void mspin_unlock(struct mspin_node **lock, struct mspin_node *node)
@@ -158,8 +158,8 @@ static void mspin_unlock(struct mspin_node **lock, struct mspin_node *node)
 		if (cmpxchg(lock, node, NULL) == node)
 			return;
 		/* Wait until the next pointer is set */
-		while (!(next = ACCESS_ONCE(node->next)))
-			arch_mutex_cpu_relax();
+		while (!(next = (struct mspin_node*)(cpu_relaxed_read_long(&(node->next)))))
+			cpu_read_relax();
 	}
 	ACCESS_ONCE(next->locked) = 1;
 	smp_wmb();
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index c6d3219b1..265f8359e 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1271,9 +1271,10 @@ unsigned long wait_task_inactive(struct task_struct *p, long match_state)
 		 * is actually now running somewhere else!
 		 */
 		while (task_running(rq, p)) {
-			if (match_state && unlikely(p->state != match_state))
+			if (match_state && unlikely(cpu_relaxed_read_long
+				(&(p->state)) != match_state))
 				return 0;
-			cpu_relax();
+			cpu_read_relax();
 		}
 
 		/*
@@ -1603,7 +1604,7 @@ enum ipi_msg_type {
 };
 void scheduler_ipi(void)
 {
-	if (llist_empty(&this_rq()->wake_list)
+	if (llist_empty_relaxed(&this_rq()->wake_list)
 			&& !tick_nohz_full_cpu(smp_processor_id())
 			&& !got_nohz_idle_kick()){
         mt_trace_ISR_start(IPI_RESCHEDULE);
@@ -1753,8 +1754,8 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags)
 	 * If the owning (remote) cpu is still in the middle of schedule() with
 	 * this task as prev, wait until its done referencing the task.
 	 */
-	while (p->on_cpu)
-		cpu_relax();
+	while (cpu_relaxed_read(&(p->on_cpu)))
+		cpu_read_relax();
 	/*
 	 * Pairs with the smp_wmb() in finish_lock_switch().
 	 */
@@ -4261,7 +4262,7 @@ int idle_cpu(int cpu)
 		return 0;
 
 #ifdef CONFIG_SMP
-	if (!llist_empty(&rq->wake_list))
+	if (!llist_empty_relaxed(&rq->wake_list))
 		return 0;
 #endif
 
diff --git a/kernel/smp.c b/kernel/smp.c
index 87f82e6cc..d02575408 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -12,6 +12,7 @@
 #include <linux/gfp.h>
 #include <linux/smp.h>
 #include <linux/cpu.h>
+#include <asm/relaxed.h>
 
 #include "smpboot.h"
 
@@ -101,8 +102,8 @@ void __init call_function_init(void)
  */
 static void csd_lock_wait(struct call_single_data *csd)
 {
-	while (csd->flags & CSD_FLAG_LOCK)
-		cpu_relax();
+	while (cpu_relaxed_read_short(&csd->flags) & CSD_FLAG_LOCK)
+		cpu_read_relax();
 }
 
 static void csd_lock(struct call_single_data *csd)