[S390,PPC] Implement FUTEX_WAIT_BITSET for timedwait functions

Since the FUTEX_WAIT operation takes a relative timeout, the
pthread_cond_timedwait and other timed function implementations have
to get a relative timeout from the absolute timeout parameter it gets
before it makes the futex syscall.  This value is then converted back
into an absolute timeout within the kernel.  This is a waste and has
hence been improved upon by a FUTEX_WAIT_BITSET operation (OR'd with
FUTEX_CLOCK_REALTIME to make the kernel use the realtime clock instead
of the default monotonic clock).  This was implemented only in the x86
and sh assembly code and not in the C code.  This patch implements
support for FUTEX_WAIT_BITSET whenever available (since linux-2.6.29)
for s390 and powerpc.

1 files changed, 20 insertions, 0 deletions

diff --git a/nptl/sysdeps/unix/sysv/linux/s390/lowlevellock.h b/nptl/sysdeps/unix/sysv/linux/s390/lowlevellock.h
index 97092823df..0b7110f11b 100644
--- a/nptl/sysdeps/unix/sysv/linux/s390/lowlevellock.h
+++ b/nptl/sysdeps/unix/sysv/linux/s390/lowlevellock.h
@@ -93,6 +93,26 @@
     __result;								      \
   })
 
+#define lll_futex_timed_wait_bitset(futexp, val, timespec, clockbit, private) \
+  ({									      \
+    register unsigned long int __r2 asm ("2") = (unsigned long int) (futexp); \
+    register unsigned long int __r3 asm ("3")				      \
+      = __lll_private_flag ((FUTEX_WAIT_BITSET | clockbit), private);	      \
+    register unsigned long int __r4 asm ("4") = (long int) (val);	      \
+    register unsigned long int __r5 asm ("5") = (long int) (timespec);	      \
+    register unsigned long int __r6 asm ("6") = (unsigned long int) (NULL);   \
+    register unsigned long int __r7 asm ("7")				      \
+      = (unsigned int) (FUTEX_BITSET_MATCH_ANY);			      \
+    register unsigned long __result asm ("2");				      \
+									      \
+    __asm __volatile ("svc %b1"						      \
+		      : "=d" (__result)					      \
+		      : "i" (SYS_futex), "0" (__r2), "d" (__r3),	      \
+			"d" (__r4), "d" (__r5), "d" (__r6), "d" (__r7)	      \
+		      : "cc", "memory" );				      \
+    __result;								      \
+  })
+
 
 #define lll_futex_wake(futex, nr, private) \
   ({									      \