Merge branch 'origin'

[pandora-kernel.git] / kernel / itimer.c

diff --git a/kernel/itimer.c b/kernel/itimer.c
index 7c1b25e..379be2f 100644 (file)
--- a/kernel/itimer.c
+++ b/kernel/itimer.c
@@ -12,36 +12,48 @@
 #include <linux/syscalls.h>
 #include <linux/time.h>
 #include <linux/posix-timers.h>
+#include <linux/hrtimer.h>
 
 #include <asm/uaccess.h>
 
-static unsigned long it_real_value(struct signal_struct *sig)
+/**
+ * itimer_get_remtime - get remaining time for the timer
+ *
+ * @timer: the timer to read
+ *
+ * Returns the delta between the expiry time and now, which can be
+ * less than zero or 1usec for an pending expired timer
+ */
+static struct timeval itimer_get_remtime(struct hrtimer *timer)
 {
-       unsigned long val = 0;
-       if (timer_pending(&sig->real_timer)) {
-               val = sig->real_timer.expires - jiffies;
+       ktime_t rem = hrtimer_get_remaining(timer);
 
-               /* look out for negative/zero itimer.. */
-               if ((long) val <= 0)
-                       val = 1;
-       }
-       return val;
+       /*
+        * Racy but safe: if the itimer expires after the above
+        * hrtimer_get_remtime() call but before this condition
+        * then we return 0 - which is correct.
+        */
+       if (hrtimer_active(timer)) {
+               if (rem.tv64 <= 0)
+                       rem.tv64 = NSEC_PER_USEC;
+       } else
+               rem.tv64 = 0;
+
+       return ktime_to_timeval(rem);
 }
 
 int do_getitimer(int which, struct itimerval *value)
 {
        struct task_struct *tsk = current;
-       unsigned long interval, val;
        cputime_t cinterval, cval;
 
        switch (which) {
        case ITIMER_REAL:
                spin_lock_irq(&tsk->sighand->siglock);
-               interval = tsk->signal->it_real_incr;
-               val = it_real_value(tsk->signal);
+               value->it_value = itimer_get_remtime(&tsk->signal->real_timer);
+               value->it_interval =
+                       ktime_to_timeval(tsk->signal->it_real_incr);
                spin_unlock_irq(&tsk->sighand->siglock);
-               jiffies_to_timeval(val, &value->it_value);
-               jiffies_to_timeval(interval, &value->it_interval);
                break;
        case ITIMER_VIRTUAL:
                read_lock(&tasklist_lock);
@@ -113,59 +125,52 @@ asmlinkage long sys_getitimer(int which, struct itimerval __user *value)
 }
 
 
-void it_real_fn(unsigned long __data)
+/*
+ * The timer is automagically restarted, when interval != 0
+ */
+int it_real_fn(void *data)
 {
-       struct task_struct * p = (struct task_struct *) __data;
-       unsigned long inc = p->signal->it_real_incr;
+       struct task_struct *tsk = (struct task_struct *) data;
 
-       send_group_sig_info(SIGALRM, SEND_SIG_PRIV, p);
+       send_group_sig_info(SIGALRM, SEND_SIG_PRIV, tsk);
 
-       /*
-        * Now restart the timer if necessary.  We don't need any locking
-        * here because do_setitimer makes sure we have finished running
-        * before it touches anything.
-        * Note, we KNOW we are (or should be) at a jiffie edge here so
-        * we don't need the +1 stuff.  Also, we want to use the prior
-        * expire value so as to not "slip" a jiffie if we are late.
-        * Deal with requesting a time prior to "now" here rather than
-        * in add_timer.
-        */
-       if (!inc)
-               return;
-       while (time_before_eq(p->signal->real_timer.expires, jiffies))
-               p->signal->real_timer.expires += inc;
-       add_timer(&p->signal->real_timer);
+       if (tsk->signal->it_real_incr.tv64 != 0) {
+               hrtimer_forward(&tsk->signal->real_timer,
+                              tsk->signal->it_real_incr);
+
+               return HRTIMER_RESTART;
+       }
+       return HRTIMER_NORESTART;
 }
 
 int do_setitimer(int which, struct itimerval *value, struct itimerval *ovalue)
 {
        struct task_struct *tsk = current;
-       unsigned long val, interval, expires;
+       struct hrtimer *timer;
+       ktime_t expires;
        cputime_t cval, cinterval, nval, ninterval;
 
        switch (which) {
        case ITIMER_REAL:
 again:
                spin_lock_irq(&tsk->sighand->siglock);
-               interval = tsk->signal->it_real_incr;
-               val = it_real_value(tsk->signal);
+               timer = &tsk->signal->real_timer;
+               if (ovalue) {
+                       ovalue->it_value = itimer_get_remtime(timer);
+                       ovalue->it_interval
+                               = ktime_to_timeval(tsk->signal->it_real_incr);
+               }
                /* We are sharing ->siglock with it_real_fn() */
-               if (try_to_del_timer_sync(&tsk->signal->real_timer) < 0) {
+               if (hrtimer_try_to_cancel(timer) < 0) {
                        spin_unlock_irq(&tsk->sighand->siglock);
                        goto again;
                }
                tsk->signal->it_real_incr =
-                       timeval_to_jiffies(&value->it_interval);
-               expires = timeval_to_jiffies(&value->it_value);
-               if (expires)
-                       mod_timer(&tsk->signal->real_timer,
-                                 jiffies + 1 + expires);
+                       timeval_to_ktime(value->it_interval);
+               expires = timeval_to_ktime(value->it_value);
+               if (expires.tv64 != 0)
+                       hrtimer_start(timer, expires, HRTIMER_REL);
                spin_unlock_irq(&tsk->sighand->siglock);
-               if (ovalue) {
-                       jiffies_to_timeval(val, &ovalue->it_value);
-                       jiffies_to_timeval(interval,
-                                          &ovalue->it_interval);
-               }
                break;
        case ITIMER_VIRTUAL:
                nval = timeval_to_cputime(&value->it_value);