s390: move cputime accounting fields from thread_info to thread_struct

The user_timer and system_timer fields are used for the per-thread
cputime accounting code. The access to these values is simpler if
they are moved to the thread_struct as the task_thread_info(tsk)
indirection is not needed anymore.
Reviewed-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/include/asm/processor.h

@@ -110,6 +110,8 @@ typedef struct {
 struct thread_struct {
 	unsigned int  acrs[NUM_ACRS];
         unsigned long ksp;              /* kernel stack pointer             */
+	unsigned long user_timer;	/* task cputime in user space */
+	unsigned long system_timer;	/* task cputime in kernel space */
 	mm_segment_t mm_segment;
 	unsigned long gmap_addr;	/* address of last gmap fault. */
 	unsigned int gmap_write_flag;	/* gmap fault write indication */

arch/s390/include/asm/thread_info.h

@@ -32,8 +32,6 @@
 struct thread_info {
 	unsigned long		flags;		/* low level flags */
 	unsigned long		sys_call_table;	/* System call table address */
-	__u64			user_timer;
-	__u64			system_timer;
 	unsigned long		last_break;	/* last breaking-event-address. */
 };
 

arch/s390/kernel/asm-offsets.c

@@ -41,8 +41,6 @@ int main(void)
 	/* thread info offsets */
 	OFFSET(__TI_flags, task_struct, thread_info.flags);
 	OFFSET(__TI_sysc_table,  task_struct, thread_info.sys_call_table);
-	OFFSET(__TI_user_timer, task_struct, thread_info.user_timer);
-	OFFSET(__TI_system_timer, task_struct, thread_info.system_timer);
 	OFFSET(__TI_last_break, task_struct, thread_info.last_break);
 	BLANK();
 	/* pt_regs offsets */

arch/s390/kernel/process.c

@@ -103,7 +103,6 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
 int copy_thread(unsigned long clone_flags, unsigned long new_stackp,
 		unsigned long arg, struct task_struct *p)
 {
-	struct thread_info *ti;
 	struct fake_frame
 	{
 		struct stack_frame sf;
@@ -121,9 +120,8 @@ int copy_thread(unsigned long clone_flags, unsigned long new_stackp,
 	memset(&p->thread.per_event, 0, sizeof(p->thread.per_event));
 	clear_tsk_thread_flag(p, TIF_SINGLE_STEP);
 	/* Initialize per thread user and system timer values */
-	ti = task_thread_info(p);
-	ti->user_timer = 0;
-	ti->system_timer = 0;
+	p->thread.user_timer = 0;
+	p->thread.system_timer = 0;
 
 	frame->sf.back_chain = 0;
 	/* new return point is ret_from_fork */

arch/s390/kernel/smp.c

@@ -259,15 +259,14 @@ static void pcpu_prepare_secondary(struct pcpu *pcpu, int cpu)
 static void pcpu_attach_task(struct pcpu *pcpu, struct task_struct *tsk)
 {
 	struct lowcore *lc = pcpu->lowcore;
-	struct thread_info *ti = task_thread_info(tsk);
 
 	lc->kernel_stack = (unsigned long) task_stack_page(tsk)
 		+ THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
 	lc->current_task = (unsigned long) tsk;
 	lc->lpp = LPP_MAGIC;
 	lc->current_pid = tsk->pid;
-	lc->user_timer = ti->user_timer;
-	lc->system_timer = ti->system_timer;
+	lc->user_timer = tsk->thread.user_timer;
+	lc->system_timer = tsk->thread.system_timer;
 	lc->steal_timer = 0;
 }
 

arch/s390/kernel/vtime.c

@@ -96,7 +96,6 @@ static void update_mt_scaling(void)
  */
 static int do_account_vtime(struct task_struct *tsk, int hardirq_offset)
 {
-	struct thread_info *ti = task_thread_info(tsk);
 	u64 timer, clock, user, system, steal;
 	u64 user_scaled, system_scaled;
 
@@ -119,13 +118,13 @@ static int do_account_vtime(struct task_struct *tsk, int hardirq_offset)
 	    time_after64(jiffies_64, this_cpu_read(mt_scaling_jiffies)))
 		update_mt_scaling();
 
-	user = S390_lowcore.user_timer - ti->user_timer;
+	user = S390_lowcore.user_timer - tsk->thread.user_timer;
 	S390_lowcore.steal_timer -= user;
-	ti->user_timer = S390_lowcore.user_timer;
+	tsk->thread.user_timer = S390_lowcore.user_timer;
 
-	system = S390_lowcore.system_timer - ti->system_timer;
+	system = S390_lowcore.system_timer - tsk->thread.system_timer;
 	S390_lowcore.steal_timer -= system;
-	ti->system_timer = S390_lowcore.system_timer;
+	tsk->thread.system_timer = S390_lowcore.system_timer;
 
 	user_scaled = user;
 	system_scaled = system;
@@ -151,15 +150,11 @@ static int do_account_vtime(struct task_struct *tsk, int hardirq_offset)
 
 void vtime_task_switch(struct task_struct *prev)
 {
-	struct thread_info *ti;
-
 	do_account_vtime(prev, 0);
-	ti = task_thread_info(prev);
-	ti->user_timer = S390_lowcore.user_timer;
-	ti->system_timer = S390_lowcore.system_timer;
-	ti = task_thread_info(current);
-	S390_lowcore.user_timer = ti->user_timer;
-	S390_lowcore.system_timer = ti->system_timer;
+	prev->thread.user_timer = S390_lowcore.user_timer;
+	prev->thread.system_timer = S390_lowcore.system_timer;
+	S390_lowcore.user_timer = current->thread.user_timer;
+	S390_lowcore.system_timer = current->thread.system_timer;
 }
 
 /*
@@ -179,7 +174,6 @@ void vtime_account_user(struct task_struct *tsk)
  */
 void vtime_account_irq_enter(struct task_struct *tsk)
 {
-	struct thread_info *ti = task_thread_info(tsk);
 	u64 timer, system, system_scaled;
 
 	timer = S390_lowcore.last_update_timer;
@@ -191,9 +185,9 @@ void vtime_account_irq_enter(struct task_struct *tsk)
 	    time_after64(jiffies_64, this_cpu_read(mt_scaling_jiffies)))
 		update_mt_scaling();
 
-	system = S390_lowcore.system_timer - ti->system_timer;
+	system = S390_lowcore.system_timer - tsk->thread.system_timer;
 	S390_lowcore.steal_timer -= system;
-	ti->system_timer = S390_lowcore.system_timer;
+	tsk->thread.system_timer = S390_lowcore.system_timer;
 	system_scaled = system;
 	/* Do MT utilization scaling */
 	if (smp_cpu_mtid) {