uml: time build fix

Put back an implementation of timeval_to_ns in arch/um/os-Linux/time.c.
tglx pointed out in his review of tickless support that there was a
perfectly good implementation of it in linux/time.h.  The problem is that
this is userspace code which can't pull in kernel headers and there doesn't
seem to be a libc version.

So, I'm copying the version from linux/time.h rather than resurrecting my
version.  This causes some declaration changes as it now returns a signed
value rather than an unsigned value.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 21 insertions, 5 deletions

diff --git a/arch/um/include/os.h b/arch/um/include/os.h
index 91642e4137d7..a1b0804ee57b 100644
--- a/arch/um/include/os.h
+++ b/arch/um/include/os.h
@@ -254,9 +254,9 @@ extern void os_dump_core(void);
 extern void idle_sleep(unsigned long long nsecs);
 extern int set_interval(void);
 extern int timer_one_shot(int ticks);
-extern unsigned long long disable_timer(void);
+extern long long disable_timer(void);
 extern void uml_idle_timer(void);
-extern unsigned long long os_nsecs(void);
+extern long long os_nsecs(void);
 
 /* skas/mem.c */
 extern long run_syscall_stub(struct mm_id * mm_idp,
diff --git a/arch/um/os-Linux/time.c b/arch/um/os-Linux/time.c
index d2cb161ae2b3..574b134f0502 100644
--- a/arch/um/os-Linux/time.c
+++ b/arch/um/os-Linux/time.c
@@ -39,7 +39,23 @@ int timer_one_shot(int ticks)
         return 0;
 }
 
-unsigned long long disable_timer(void)
+/**
+ * timeval_to_ns - Convert timeval to nanoseconds
+ * @ts:         pointer to the timeval variable to be converted
+ *
+ * Returns the scalar nanosecond representation of the timeval
+ * parameter.
+ *
+ * Ripped from linux/time.h because it's a kernel header, and thus
+ * unusable from here.
+ */
+static inline long long timeval_to_ns(const struct timeval *tv)
+{
+        return ((long long) tv->tv_sec * UM_NSEC_PER_SEC) +
+                tv->tv_usec * UM_NSEC_PER_USEC;
+}
+
+long long disable_timer(void)
 {
         struct itimerval time = ((struct itimerval) { { 0, 0 }, { 0, 0 } });
 
@@ -47,10 +63,10 @@ unsigned long long disable_timer(void)
                 printk(UM_KERN_ERR "disable_timer - setitimer failed, "
                        "errno = %d\n", errno);
 
-        return tv_to_nsec(&time.it_value);
+        return timeval_to_ns(&time.it_value);
 }
 
-unsigned long long os_nsecs(void)
+long long os_nsecs(void)
 {
         struct timeval tv;