[S390] cputime: add sparse checking and cleanup

Make cputime_t and cputime64_t nocast to enable sparse checking to
detect incorrect use of cputime. Drop the cputime macros for simple
scalar operations. The conversion macros are still needed.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 52 insertions, 80 deletions

diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index e7cb76dc18f5..125cb67daa21 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -78,7 +78,7 @@ static inline int cpu_time_before(const clockid_t which_clock,
         if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) {
                 return now.sched < then.sched;
         }  else {
-                return cputime_lt(now.cpu, then.cpu);
+                return now.cpu < then.cpu;
         }
 }
 static inline void cpu_time_add(const clockid_t which_clock,
@@ -88,7 +88,7 @@ static inline void cpu_time_add(const clockid_t which_clock,
         if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) {
                 acc->sched += val.sched;
         }  else {
-                acc->cpu = cputime_add(acc->cpu, val.cpu);
+                acc->cpu += val.cpu;
         }
 }
 static inline union cpu_time_count cpu_time_sub(const clockid_t which_clock,
@@ -98,25 +98,12 @@ static inline union cpu_time_count cpu_time_sub(const clockid_t which_clock,
         if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) {
                 a.sched -= b.sched;
         }  else {
-                a.cpu = cputime_sub(a.cpu, b.cpu);
+                a.cpu -= b.cpu;
         }
         return a;
 }
 
 /*
- * Divide and limit the result to res >= 1
- *
- * This is necessary to prevent signal delivery starvation, when the result of
- * the division would be rounded down to 0.
- */
-static inline cputime_t cputime_div_non_zero(cputime_t time, unsigned long div)
-{
-        cputime_t res = cputime_div(time, div);
-
-        return max_t(cputime_t, res, 1);
-}
-
-/*
  * Update expiry time from increment, and increase overrun count,
  * given the current clock sample.
  */
@@ -148,28 +135,26 @@ static void bump_cpu_timer(struct k_itimer *timer,
         } else {
                 cputime_t delta, incr;
 
-                if (cputime_lt(now.cpu, timer->it.cpu.expires.cpu))
+                if (now.cpu < timer->it.cpu.expires.cpu)
                         return;
                 incr = timer->it.cpu.incr.cpu;
-                delta = cputime_sub(cputime_add(now.cpu, incr),
-                                    timer->it.cpu.expires.cpu);
+                delta = now.cpu + incr - timer->it.cpu.expires.cpu;
                 /* Don't use (incr*2 < delta), incr*2 might overflow. */
-                for (i = 0; cputime_lt(incr, cputime_sub(delta, incr)); i++)
-                             incr = cputime_add(incr, incr);
-                for (; i >= 0; incr = cputime_halve(incr), i--) {
-                        if (cputime_lt(delta, incr))
+                for (i = 0; incr < delta - incr; i++)
+                             incr += incr;
+                for (; i >= 0; incr = incr >> 1, i--) {
+                        if (delta < incr)
                                 continue;
-                        timer->it.cpu.expires.cpu =
-                                cputime_add(timer->it.cpu.expires.cpu, incr);
+                        timer->it.cpu.expires.cpu += incr;
                         timer->it_overrun += 1 << i;
-                        delta = cputime_sub(delta, incr);
+                        delta -= incr;
                 }
         }
 }
 
 static inline cputime_t prof_ticks(struct task_struct *p)
 {
-        return cputime_add(p->utime, p->stime);
+        return p->utime + p->stime;
 }
 static inline cputime_t virt_ticks(struct task_struct *p)
 {
@@ -248,8 +233,8 @@ void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times)
 
         t = tsk;
         do {
-                times->utime = cputime_add(times->utime, t->utime);
-                times->stime = cputime_add(times->stime, t->stime);
+                times->utime += t->utime;
+                times->stime += t->stime;
                 times->sum_exec_runtime += task_sched_runtime(t);
         } while_each_thread(tsk, t);
 out:
@@ -258,10 +243,10 @@ out:
 
 static void update_gt_cputime(struct task_cputime *a, struct task_cputime *b)
 {
-        if (cputime_gt(b->utime, a->utime))
+        if (b->utime > a->utime)
                 a->utime = b->utime;
 
-        if (cputime_gt(b->stime, a->stime))
+        if (b->stime > a->stime)
                 a->stime = b->stime;
 
         if (b->sum_exec_runtime > a->sum_exec_runtime)
@@ -306,7 +291,7 @@ static int cpu_clock_sample_group(const clockid_t which_clock,
                 return -EINVAL;
         case CPUCLOCK_PROF:
                 thread_group_cputime(p, &cputime);
-                cpu->cpu = cputime_add(cputime.utime, cputime.stime);
+                cpu->cpu = cputime.utime + cputime.stime;
                 break;
         case CPUCLOCK_VIRT:
                 thread_group_cputime(p, &cputime);
@@ -470,26 +455,24 @@ static void cleanup_timers(struct list_head *head,
                            unsigned long long sum_exec_runtime)
 {
         struct cpu_timer_list *timer, *next;
-        cputime_t ptime = cputime_add(utime, stime);
+        cputime_t ptime = utime + stime;
 
         list_for_each_entry_safe(timer, next, head, entry) {
                 list_del_init(&timer->entry);
-                if (cputime_lt(timer->expires.cpu, ptime)) {
-                        timer->expires.cpu = cputime_zero;
+                if (timer->expires.cpu < ptime) {
+                        timer->expires.cpu = 0;
                 } else {
-                        timer->expires.cpu = cputime_sub(timer->expires.cpu,
-                                                         ptime);
+                        timer->expires.cpu -= ptime;
                 }
         }
 
         ++head;
         list_for_each_entry_safe(timer, next, head, entry) {
                 list_del_init(&timer->entry);
-                if (cputime_lt(timer->expires.cpu, utime)) {
-                        timer->expires.cpu = cputime_zero;
+                if (timer->expires.cpu < utime) {
+                        timer->expires.cpu = 0;
                 } else {
-                        timer->expires.cpu = cputime_sub(timer->expires.cpu,
-                                                         utime);
+                        timer->expires.cpu -= utime;
                 }
         }
 
@@ -520,8 +503,7 @@ void posix_cpu_timers_exit_group(struct task_struct *tsk)
         struct signal_struct *const sig = tsk->signal;
 
         cleanup_timers(tsk->signal->cpu_timers,
-                       cputime_add(tsk->utime, sig->utime),
-                       cputime_add(tsk->stime, sig->stime),
+                       tsk->utime + sig->utime, tsk->stime + sig->stime,
                        tsk->se.sum_exec_runtime + sig->sum_sched_runtime);
 }
 
@@ -540,8 +522,7 @@ static void clear_dead_task(struct k_itimer *timer, union cpu_time_count now)
 
 static inline int expires_gt(cputime_t expires, cputime_t new_exp)
 {
-        return cputime_eq(expires, cputime_zero) ||
-               cputime_gt(expires, new_exp);
+        return expires == 0 || expires > new_exp;
 }
 
 /*
@@ -651,7 +632,7 @@ static int cpu_timer_sample_group(const clockid_t which_clock,
         default:
                 return -EINVAL;
         case CPUCLOCK_PROF:
-                cpu->cpu = cputime_add(cputime.utime, cputime.stime);
+                cpu->cpu = cputime.utime + cputime.stime;
                 break;
         case CPUCLOCK_VIRT:
                 cpu->cpu = cputime.utime;
@@ -918,12 +899,12 @@ static void check_thread_timers(struct task_struct *tsk,
         unsigned long soft;
 
         maxfire = 20;
-        tsk->cputime_expires.prof_exp = cputime_zero;
+        tsk->cputime_expires.prof_exp = 0;
         while (!list_empty(timers)) {
                 struct cpu_timer_list *t = list_first_entry(timers,
                                                       struct cpu_timer_list,
                                                       entry);
-                if (!--maxfire || cputime_lt(prof_ticks(tsk), t->expires.cpu)) {
+                if (!--maxfire || prof_ticks(tsk) < t->expires.cpu) {
                         tsk->cputime_expires.prof_exp = t->expires.cpu;
                         break;
                 }
@@ -933,12 +914,12 @@ static void check_thread_timers(struct task_struct *tsk,
 
         ++timers;
         maxfire = 20;
-        tsk->cputime_expires.virt_exp = cputime_zero;
+        tsk->cputime_expires.virt_exp = 0;
         while (!list_empty(timers)) {
                 struct cpu_timer_list *t = list_first_entry(timers,
                                                       struct cpu_timer_list,
                                                       entry);
-                if (!--maxfire || cputime_lt(virt_ticks(tsk), t->expires.cpu)) {
+                if (!--maxfire || virt_ticks(tsk) < t->expires.cpu) {
                         tsk->cputime_expires.virt_exp = t->expires.cpu;
                         break;
                 }
@@ -1009,20 +990,19 @@ static u32 onecputick;
 static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it,
                              cputime_t *expires, cputime_t cur_time, int signo)
 {
-        if (cputime_eq(it->expires, cputime_zero))
+        if (!it->expires)
                 return;
 
-        if (cputime_ge(cur_time, it->expires)) {
-                if (!cputime_eq(it->incr, cputime_zero)) {
-                        it->expires = cputime_add(it->expires, it->incr);
+        if (cur_time >= it->expires) {
+                if (it->incr) {
+                        it->expires += it->incr;
                         it->error += it->incr_error;
                         if (it->error >= onecputick) {
-                                it->expires = cputime_sub(it->expires,
-                                                          cputime_one_jiffy);
+                                it->expires -= cputime_one_jiffy;
                                 it->error -= onecputick;
                         }
                 } else {
-                        it->expires = cputime_zero;
+                        it->expires = 0;
                 }
 
                 trace_itimer_expire(signo == SIGPROF ?
@@ -1031,9 +1011,7 @@ static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it,
                 __group_send_sig_info(signo, SEND_SIG_PRIV, tsk);
         }
 
-        if (!cputime_eq(it->expires, cputime_zero) &&
-            (cputime_eq(*expires, cputime_zero) ||
-             cputime_lt(it->expires, *expires))) {
+        if (it->expires && (!*expires || it->expires < *expires)) {
                 *expires = it->expires;
         }
 }
@@ -1048,9 +1026,7 @@ static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it,
  */
 static inline int task_cputime_zero(const struct task_cputime *cputime)
 {
-        if (cputime_eq(cputime->utime, cputime_zero) &&
-            cputime_eq(cputime->stime, cputime_zero) &&
-            cputime->sum_exec_runtime == 0)
+        if (!cputime->utime && !cputime->stime && !cputime->sum_exec_runtime)
                 return 1;
         return 0;
 }
@@ -1076,15 +1052,15 @@ static void check_process_timers(struct task_struct *tsk,
          */
         thread_group_cputimer(tsk, &cputime);
         utime = cputime.utime;
-        ptime = cputime_add(utime, cputime.stime);
+        ptime = utime + cputime.stime;
         sum_sched_runtime = cputime.sum_exec_runtime;
         maxfire = 20;
-        prof_expires = cputime_zero;
+        prof_expires = 0;
         while (!list_empty(timers)) {
                 struct cpu_timer_list *tl = list_first_entry(timers,
                                                       struct cpu_timer_list,
                                                       entry);
-                if (!--maxfire || cputime_lt(ptime, tl->expires.cpu)) {
+                if (!--maxfire || ptime < tl->expires.cpu) {
                         prof_expires = tl->expires.cpu;
                         break;
                 }
@@ -1094,12 +1070,12 @@ static void check_process_timers(struct task_struct *tsk,
 
         ++timers;
         maxfire = 20;
-        virt_expires = cputime_zero;
+        virt_expires = 0;
         while (!list_empty(timers)) {
                 struct cpu_timer_list *tl = list_first_entry(timers,
                                                       struct cpu_timer_list,
                                                       entry);
-                if (!--maxfire || cputime_lt(utime, tl->expires.cpu)) {
+                if (!--maxfire || utime < tl->expires.cpu) {
                         virt_expires = tl->expires.cpu;
                         break;
                 }
@@ -1154,8 +1130,7 @@ static void check_process_timers(struct task_struct *tsk,
                         }
                 }
                 x = secs_to_cputime(soft);
-                if (cputime_eq(prof_expires, cputime_zero) ||
-                    cputime_lt(x, prof_expires)) {
+                if (!prof_expires || x < prof_expires) {
                         prof_expires = x;
                 }
         }
@@ -1249,12 +1224,9 @@ out:
 static inline int task_cputime_expired(const struct task_cputime *sample,
                                         const struct task_cputime *expires)
 {
-        if (!cputime_eq(expires->utime, cputime_zero) &&
-            cputime_ge(sample->utime, expires->utime))
+        if (expires->utime && sample->utime >= expires->utime)
                 return 1;
-        if (!cputime_eq(expires->stime, cputime_zero) &&
-            cputime_ge(cputime_add(sample->utime, sample->stime),
-                       expires->stime))
+        if (expires->stime && sample->utime + sample->stime >= expires->stime)
                 return 1;
         if (expires->sum_exec_runtime != 0 &&
             sample->sum_exec_runtime >= expires->sum_exec_runtime)
@@ -1389,18 +1361,18 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx,
                  * it to be relative, *newval argument is relative and we update
                  * it to be absolute.
                  */
-                if (!cputime_eq(*oldval, cputime_zero)) {
-                        if (cputime_le(*oldval, now.cpu)) {
+                if (*oldval) {
+                        if (*oldval <= now.cpu) {
                                 /* Just about to fire. */
                                 *oldval = cputime_one_jiffy;
                         } else {
-                                *oldval = cputime_sub(*oldval, now.cpu);
+                                *oldval -= now.cpu;
                         }
                 }
 
-                if (cputime_eq(*newval, cputime_zero))
+                if (!*newval)
                         return;
-                *newval = cputime_add(*newval, now.cpu);
+                *newval += now.cpu;
         }
 
         /*