[PATCH v4 1/4] perf bench futex: Call the futex syscall from a function

[Alistair Francis]

From: Alistair Francis <alistair.francis at wdc.com>

In preparation for a more complex futex() function let's convert the
current macro into two functions. We need two functions to avoid
compiler failures as the macro is overloaded.

This will allow us to include pre-processor conditionals in the futex
syscall functions.

Signed-off-by: Alistair Francis <alistair.francis at wdc.com>
Acked-by: Davidlohr Bueso <dbueso at suse.de>
---
 tools/perf/bench/futex.h | 43 ++++++++++++++++++++++++----------------
 1 file changed, 26 insertions(+), 17 deletions(-)

diff --git a/tools/perf/bench/futex.h b/tools/perf/bench/futex.h
index b3853aac3021c..b97a343e7ec66 100644
--- a/tools/perf/bench/futex.h
+++ b/tools/perf/bench/futex.h
@@ -28,7 +28,7 @@ struct bench_futex_parameters {
 };
 
 /**
- * futex() - SYS_futex syscall wrapper
+ * futex_syscall() - SYS_futex syscall wrapper
  * @uaddr:	address of first futex
  * @op:		futex op code
  * @val:	typically expected value of uaddr, but varies by op
@@ -38,17 +38,26 @@ struct bench_futex_parameters {
  * @val3:	varies by op
  * @opflags:	flags to be bitwise OR'd with op, such as FUTEX_PRIVATE_FLAG
  *
- * futex() is used by all the following futex op wrappers. It can also be
+ * futex_syscall() is used by all the following futex op wrappers. It can also be
  * used for misuse and abuse testing. Generally, the specific op wrappers
- * should be used instead. It is a macro instead of an static inline function as
- * some of the types over overloaded (timeout is used for nr_requeue for
- * example).
+ * should be used instead.
  *
  * These argument descriptions are the defaults for all
  * like-named arguments in the following wrappers except where noted below.
  */
-#define futex(uaddr, op, val, timeout, uaddr2, val3, opflags) \
-	syscall(SYS_futex, uaddr, op | opflags, val, timeout, uaddr2, val3)
+static inline int
+futex_syscall(volatile u_int32_t *uaddr, int op, u_int32_t val, struct timespec *timeout,
+	      volatile u_int32_t *uaddr2, int val3, int opflags)
+{
+	return syscall(SYS_futex, uaddr, op | opflags, val, ts32, uaddr2, val3);
+}
+
+static inline int
+futex_syscall_nr_requeue(volatile u_int32_t *uaddr, int op, u_int32_t val, int nr_requeue,
+			 volatile u_int32_t *uaddr2, int val3, int opflags)
+{
+	return syscall(SYS_futex, uaddr, op | opflags, val, nr_requeue, uaddr2, val3);
+}
 
 /**
  * futex_wait() - block on uaddr with optional timeout
@@ -57,7 +66,7 @@ struct bench_futex_parameters {
 static inline int
 futex_wait(u_int32_t *uaddr, u_int32_t val, struct timespec *timeout, int opflags)
 {
-	return futex(uaddr, FUTEX_WAIT, val, timeout, NULL, 0, opflags);
+	return futex_syscall(uaddr, FUTEX_WAIT, val, timeout, NULL, 0, opflags);
 }
 
 /**
@@ -67,7 +76,7 @@ futex_wait(u_int32_t *uaddr, u_int32_t val, struct timespec *timeout, int opflag
 static inline int
 futex_wake(u_int32_t *uaddr, int nr_wake, int opflags)
 {
-	return futex(uaddr, FUTEX_WAKE, nr_wake, NULL, NULL, 0, opflags);
+	return futex_syscall(uaddr, FUTEX_WAKE, nr_wake, NULL, NULL, 0, opflags);
 }
 
 /**
@@ -76,7 +85,7 @@ futex_wake(u_int32_t *uaddr, int nr_wake, int opflags)
 static inline int
 futex_lock_pi(u_int32_t *uaddr, struct timespec *timeout, int opflags)
 {
-	return futex(uaddr, FUTEX_LOCK_PI, 0, timeout, NULL, 0, opflags);
+	return futex_syscall(uaddr, FUTEX_LOCK_PI, 0, timeout, NULL, 0, opflags);
 }
 
 /**
@@ -85,7 +94,7 @@ futex_lock_pi(u_int32_t *uaddr, struct timespec *timeout, int opflags)
 static inline int
 futex_unlock_pi(u_int32_t *uaddr, int opflags)
 {
-	return futex(uaddr, FUTEX_UNLOCK_PI, 0, NULL, NULL, 0, opflags);
+	return futex_syscall(uaddr, FUTEX_UNLOCK_PI, 0, NULL, NULL, 0, opflags);
 }
 
 /**
@@ -97,8 +106,8 @@ static inline int
 futex_cmp_requeue(u_int32_t *uaddr, u_int32_t val, u_int32_t *uaddr2, int nr_wake,
 		 int nr_requeue, int opflags)
 {
-	return futex(uaddr, FUTEX_CMP_REQUEUE, nr_wake, nr_requeue, uaddr2,
-		 val, opflags);
+	return futex_syscall_nr_requeue(uaddr, FUTEX_CMP_REQUEUE, nr_wake, nr_requeue, uaddr2,
+					val, opflags);
 }
 
 /**
@@ -113,8 +122,8 @@ static inline int
 futex_wait_requeue_pi(u_int32_t *uaddr, u_int32_t val, u_int32_t *uaddr2,
 		      struct timespec *timeout, int opflags)
 {
-	return futex(uaddr, FUTEX_WAIT_REQUEUE_PI, val, timeout, uaddr2, 0,
-		     opflags);
+	return futex_syscall(uaddr, FUTEX_WAIT_REQUEUE_PI, val, timeout, uaddr2, 0,
+			     opflags);
 }
 
 /**
@@ -130,8 +139,8 @@ static inline int
 futex_cmp_requeue_pi(u_int32_t *uaddr, u_int32_t val, u_int32_t *uaddr2,
 		     int nr_requeue, int opflags)
 {
-	return futex(uaddr, FUTEX_CMP_REQUEUE_PI, 1, nr_requeue, uaddr2,
-		     val, opflags);
+	return futex_syscall_nr_requeue(uaddr, FUTEX_CMP_REQUEUE_PI, 1, nr_requeue, uaddr2,
+					val, opflags);
 }
 
 #endif /* _FUTEX_H */
-- 
2.31.1