s390/vtime: Remove duplicate get_lowcore() calls

Assign the output from get_lowcore() to a local variable,
so the code is easier to read.

Acked-by: Heiko Carstens <[email protected]>
Signed-off-by: Sven Schnelle <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>

Author: svens-s390

arch/s390/include/asm/vtime.h

@@ -4,16 +4,20 @@
 
 static inline void update_timer_sys(void)
 {
-	get_lowcore()->system_timer += get_lowcore()->last_update_timer - get_lowcore()->exit_timer;
-	get_lowcore()->user_timer += get_lowcore()->exit_timer - get_lowcore()->sys_enter_timer;
-	get_lowcore()->last_update_timer = get_lowcore()->sys_enter_timer;
+	struct lowcore *lc = get_lowcore();
+
+	lc->system_timer += lc->last_update_timer - lc->exit_timer;
+	lc->user_timer += lc->exit_timer - lc->sys_enter_timer;
+	lc->last_update_timer = lc->sys_enter_timer;
 }
 
 static inline void update_timer_mcck(void)
 {
-	get_lowcore()->system_timer += get_lowcore()->last_update_timer - get_lowcore()->exit_timer;
-	get_lowcore()->user_timer += get_lowcore()->exit_timer - get_lowcore()->mcck_enter_timer;
-	get_lowcore()->last_update_timer = get_lowcore()->mcck_enter_timer;
+	struct lowcore *lc = get_lowcore();
+
+	lc->system_timer += lc->last_update_timer - lc->exit_timer;
+	lc->user_timer += lc->exit_timer - lc->mcck_enter_timer;
+	lc->last_update_timer = lc->mcck_enter_timer;
 }
 
 #endif /* _S390_VTIME_H */

arch/s390/kernel/vtime.c

@@ -35,14 +35,15 @@ static DEFINE_PER_CPU(u64, mt_scaling_jiffies);
 
 static inline void set_vtimer(u64 expires)
 {
+	struct lowcore *lc = get_lowcore();
 	u64 timer;
 
 	asm volatile(
 		"	stpt	%0\n"	/* Store current cpu timer value */
 		"	spt	%1"	/* Set new value imm. afterwards */
 		: "=Q" (timer) : "Q" (expires));
-	get_lowcore()->system_timer += get_lowcore()->last_update_timer - timer;
-	get_lowcore()->last_update_timer = expires;
+	lc->system_timer += lc->last_update_timer - timer;
+	lc->last_update_timer = expires;
 }
 
 static inline int virt_timer_forward(u64 elapsed)
@@ -117,22 +118,23 @@ static void account_system_index_scaled(struct task_struct *p, u64 cputime,
 static int do_account_vtime(struct task_struct *tsk)
 {
 	u64 timer, clock, user, guest, system, hardirq, softirq;
+	struct lowcore *lc = get_lowcore();
 
-	timer = get_lowcore()->last_update_timer;
-	clock = get_lowcore()->last_update_clock;
+	timer = lc->last_update_timer;
+	clock = lc->last_update_clock;
 	asm volatile(
 		"	stpt	%0\n"	/* Store current cpu timer value */
 		"	stckf	%1"	/* Store current tod clock value */
-		: "=Q" (get_lowcore()->last_update_timer),
-		  "=Q" (get_lowcore()->last_update_clock)
+		: "=Q" (lc->last_update_timer),
+		  "=Q" (lc->last_update_clock)
 		: : "cc");
-	clock = get_lowcore()->last_update_clock - clock;
-	timer -= get_lowcore()->last_update_timer;
+	clock = lc->last_update_clock - clock;
+	timer -= lc->last_update_timer;
 
 	if (hardirq_count())
-		get_lowcore()->hardirq_timer += timer;
+		lc->hardirq_timer += timer;
 	else
-		get_lowcore()->system_timer += timer;
+		lc->system_timer += timer;
 
 	/* Update MT utilization calculation */
 	if (smp_cpu_mtid &&
@@ -141,16 +143,16 @@ static int do_account_vtime(struct task_struct *tsk)
 
 	/* Calculate cputime delta */
 	user = update_tsk_timer(&tsk->thread.user_timer,
-				READ_ONCE(get_lowcore()->user_timer));
+				READ_ONCE(lc->user_timer));
 	guest = update_tsk_timer(&tsk->thread.guest_timer,
-				 READ_ONCE(get_lowcore()->guest_timer));
+				 READ_ONCE(lc->guest_timer));
 	system = update_tsk_timer(&tsk->thread.system_timer,
-				  READ_ONCE(get_lowcore()->system_timer));
+				  READ_ONCE(lc->system_timer));
 	hardirq = update_tsk_timer(&tsk->thread.hardirq_timer,
-				   READ_ONCE(get_lowcore()->hardirq_timer));
+				   READ_ONCE(lc->hardirq_timer));
 	softirq = update_tsk_timer(&tsk->thread.softirq_timer,
-				   READ_ONCE(get_lowcore()->softirq_timer));
-	get_lowcore()->steal_timer +=
+				   READ_ONCE(lc->softirq_timer));
+	lc->steal_timer +=
 		clock - user - guest - system - hardirq - softirq;
 
 	/* Push account value */
@@ -176,17 +178,19 @@ static int do_account_vtime(struct task_struct *tsk)
 
 void vtime_task_switch(struct task_struct *prev)
 {
+	struct lowcore *lc = get_lowcore();
+
 	do_account_vtime(prev);
-	prev->thread.user_timer = get_lowcore()->user_timer;
-	prev->thread.guest_timer = get_lowcore()->guest_timer;
-	prev->thread.system_timer = get_lowcore()->system_timer;
-	prev->thread.hardirq_timer = get_lowcore()->hardirq_timer;
-	prev->thread.softirq_timer = get_lowcore()->softirq_timer;
-	get_lowcore()->user_timer = current->thread.user_timer;
-	get_lowcore()->guest_timer = current->thread.guest_timer;
-	get_lowcore()->system_timer = current->thread.system_timer;
-	get_lowcore()->hardirq_timer = current->thread.hardirq_timer;
-	get_lowcore()->softirq_timer = current->thread.softirq_timer;
+	prev->thread.user_timer = lc->user_timer;
+	prev->thread.guest_timer = lc->guest_timer;
+	prev->thread.system_timer = lc->system_timer;
+	prev->thread.hardirq_timer = lc->hardirq_timer;
+	prev->thread.softirq_timer = lc->softirq_timer;
+	lc->user_timer = current->thread.user_timer;
+	lc->guest_timer = current->thread.guest_timer;
+	lc->system_timer = current->thread.system_timer;
+	lc->hardirq_timer = current->thread.hardirq_timer;
+	lc->softirq_timer = current->thread.softirq_timer;
 }
 
 /*
@@ -196,28 +200,29 @@ void vtime_task_switch(struct task_struct *prev)
  */
 void vtime_flush(struct task_struct *tsk)
 {
+	struct lowcore *lc = get_lowcore();
 	u64 steal, avg_steal;
 
 	if (do_account_vtime(tsk))
 		virt_timer_expire();
 
-	steal = get_lowcore()->steal_timer;
-	avg_steal = get_lowcore()->avg_steal_timer;
+	steal = lc->steal_timer;
+	avg_steal = lc->avg_steal_timer;
 	if ((s64) steal > 0) {
-		get_lowcore()->steal_timer = 0;
+		lc->steal_timer = 0;
 		account_steal_time(cputime_to_nsecs(steal));
 		avg_steal += steal;
 	}
-	get_lowcore()->avg_steal_timer = avg_steal / 2;
+	lc->avg_steal_timer = avg_steal / 2;
 }
 
 static u64 vtime_delta(void)
 {
-	u64 timer = get_lowcore()->last_update_timer;
-
-	get_lowcore()->last_update_timer = get_cpu_timer();
+	struct lowcore *lc = get_lowcore();
+	u64 timer = lc->last_update_timer;
 
-	return timer - get_lowcore()->last_update_timer;
+	lc->last_update_timer = get_cpu_timer();
+	return timer - lc->last_update_timer;
 }
 
 /*
@@ -226,12 +231,13 @@ static u64 vtime_delta(void)
  */
 void vtime_account_kernel(struct task_struct *tsk)
 {
+	struct lowcore *lc = get_lowcore();
 	u64 delta = vtime_delta();
 
 	if (tsk->flags & PF_VCPU)
-		get_lowcore()->guest_timer += delta;
+		lc->guest_timer += delta;
 	else
-		get_lowcore()->system_timer += delta;
+		lc->system_timer += delta;
 
 	virt_timer_forward(delta);
 }