timerfd: new timerfd API

This is the new timerfd API as it is implemented by the following patch:

int timerfd_create(int clockid, int flags);
int timerfd_settime(int ufd, int flags,
		    const struct itimerspec *utmr,
		    struct itimerspec *otmr);
int timerfd_gettime(int ufd, struct itimerspec *otmr);

The timerfd_create() API creates an un-programmed timerfd fd.  The "clockid"
parameter can be either CLOCK_MONOTONIC or CLOCK_REALTIME.

The timerfd_settime() API give new settings by the timerfd fd, by optionally
retrieving the previous expiration time (in case the "otmr" parameter is not
NULL).

The time value specified in "utmr" is absolute, if the TFD_TIMER_ABSTIME bit
is set in the "flags" parameter.  Otherwise it's a relative time.

The timerfd_gettime() API returns the next expiration time of the timer, or
{0, 0} if the timerfd has not been set yet.

Like the previous timerfd API implementation, read(2) and poll(2) are
supported (with the same interface).  Here's a simple test program I used to
exercise the new timerfd APIs:

http://www.xmailserver.org/timerfd-test2.c

[akpm@linux-foundation.org: coding-style cleanups]
[akpm@linux-foundation.org: fix ia64 build]
[akpm@linux-foundation.org: fix m68k build]
[akpm@linux-foundation.org: fix mips build]
[akpm@linux-foundation.org: fix alpha, arm, blackfin, cris, m68k, s390, sparc and sparc64 builds]
[heiko.carstens@de.ibm.com: fix s390]
[akpm@linux-foundation.org: fix powerpc build]
[akpm@linux-foundation.org: fix sparc64 more]
Signed-off-by: Davide Libenzi <davidel@xmailserver.org>
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Davide Libenzi <davidel@xmailserver.org>
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Davide Libenzi <davidel@xmailserver.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 15 insertions, 9 deletions

diff --git a/include/linux/compat.h b/include/linux/compat.h
index d38655f2be70..ae0a483bef9b 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -279,8 +279,11 @@ asmlinkage long compat_sys_utimensat(unsigned int dfd, char __user *filename,
 asmlinkage long compat_sys_signalfd(int ufd,
                                 const compat_sigset_t __user *sigmask,
                                 compat_size_t sigsetsize);
-asmlinkage long compat_sys_timerfd(int ufd, int clockid, int flags,
-                                const struct compat_itimerspec __user *utmr);
+asmlinkage long compat_sys_timerfd_settime(int ufd, int flags,
+                                   const struct compat_itimerspec __user *utmr,
+                                   struct compat_itimerspec __user *otmr);
+asmlinkage long compat_sys_timerfd_gettime(int ufd,
+                                   struct compat_itimerspec __user *otmr);
 
 #endif /* CONFIG_COMPAT */
 #endif /* _LINUX_COMPAT_H */
diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
index 3fed27c88c01..8371b664b41f 100644
--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -301,12 +301,12 @@ static inline int hrtimer_is_queued(struct hrtimer *timer)
 }
 
 /* Forward a hrtimer so it expires after now: */
-extern unsigned long
+extern u64
 hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval);
 
 /* Forward a hrtimer so it expires after the hrtimer's current now */
-static inline unsigned long hrtimer_forward_now(struct hrtimer *timer,
-                                                ktime_t interval)
+static inline u64 hrtimer_forward_now(struct hrtimer *timer,
+                                      ktime_t interval)
 {
         return hrtimer_forward(timer, timer->base->get_time(), interval);
 }
@@ -329,9 +329,9 @@ extern void hrtimer_run_pending(void);
 extern void __init hrtimers_init(void);
 
 #if BITS_PER_LONG < 64
-extern unsigned long ktime_divns(const ktime_t kt, s64 div);
+extern u64 ktime_divns(const ktime_t kt, s64 div);
 #else /* BITS_PER_LONG < 64 */
-# define ktime_divns(kt, div)           (unsigned long)((kt).tv64 / (div))
+# define ktime_divns(kt, div)           (u64)((kt).tv64 / (div))
 #endif
 
 /* Show pending timers: */
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 61def7c8fbb3..4c2577bd1c85 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -607,8 +607,11 @@ asmlinkage long sys_set_robust_list(struct robust_list_head __user *head,
                                     size_t len);
 asmlinkage long sys_getcpu(unsigned __user *cpu, unsigned __user *node, struct getcpu_cache __user *cache);
 asmlinkage long sys_signalfd(int ufd, sigset_t __user *user_mask, size_t sizemask);
-asmlinkage long sys_timerfd(int ufd, int clockid, int flags,
-                            const struct itimerspec __user *utmr);
+asmlinkage long sys_timerfd_create(int clockid, int flags);
+asmlinkage long sys_timerfd_settime(int ufd, int flags,
+                                    const struct itimerspec __user *utmr,
+                                    struct itimerspec __user *otmr);
+asmlinkage long sys_timerfd_gettime(int ufd, struct itimerspec __user *otmr);
 asmlinkage long sys_eventfd(unsigned int count);
 asmlinkage long sys_fallocate(int fd, int mode, loff_t offset, loff_t len);