From 19fd446ac576fab8c6c660b34bbf6d65d75be418 Mon Sep 17 00:00:00 2001
From: fincs <fincs@devkitpro.org>
Date: Tue, 30 Jun 2020 18:45:03 +0200
Subject: [PATCH] Add and use svcArbitrateAddressNoTimeout (minor ABI
 optimization)

---
 libctru/include/3ds/svc.h             | 17 +++++++++++++++--
 libctru/include/3ds/synchronization.h |  4 ++++
 libctru/source/svc.s                  |  5 +++++
 libctru/source/synchronization.c      |  2 +-
 4 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/libctru/include/3ds/svc.h b/libctru/include/3ds/svc.h
index bb061ea..cacedc0 100644
--- a/libctru/include/3ds/svc.h
+++ b/libctru/include/3ds/svc.h
@@ -915,9 +915,22 @@ Result svcCreateAddressArbiter(Handle *arbiter);
  * @param addr A pointer to a s32 value.
  * @param type Type of action to be performed by the arbiter
  * @param value Number of threads to signal if using @ref ARBITRATION_SIGNAL, or the value used for comparison.
- * @warning Please use \ref syncArbitrateAddress or \ref syncArbitrateAddressWithTimeout instead.
+ * @param timeout_ns Optional timeout in nanoseconds when using TIMEOUT actions, ignored otherwise. If not needed, use \ref svcArbitrateAddressNoTimeout instead.
+ * @note Usage of this syscall entails an implicit Data Memory Barrier (dmb).
+ * @warning Please use \ref syncArbitrateAddressWithTimeout instead.
  */
-Result svcArbitrateAddress(Handle arbiter, u32 addr, ArbitrationType type, s32 value, s64 nanoseconds);
+Result svcArbitrateAddress(Handle arbiter, u32 addr, ArbitrationType type, s32 value, s64 timeout_ns);
+
+/**
+ * @brief Same as \ref svcArbitrateAddress but with the timeout_ns parameter undefined.
+ * @param arbiter Handle of the arbiter
+ * @param addr A pointer to a s32 value.
+ * @param type Type of action to be performed by the arbiter
+ * @param value Number of threads to signal if using @ref ARBITRATION_SIGNAL, or the value used for comparison.
+ * @note Usage of this syscall entails an implicit Data Memory Barrier (dmb).
+ * @warning Please use \ref syncArbitrateAddress instead.
+ */
+Result svcArbitrateAddressNoTimeout(Handle arbiter, u32 addr, ArbitrationType type, s32 value);
 
 /**
  * @brief Sends a synchronized request to a session handle.
diff --git a/libctru/include/3ds/synchronization.h b/libctru/include/3ds/synchronization.h
index 85c2e5c..9ba9339 100755
--- a/libctru/include/3ds/synchronization.h
+++ b/libctru/include/3ds/synchronization.h
@@ -144,6 +144,8 @@ static inline bool __strexb(u8* addr, u8 val)
  * // Does *nothing* since val >= 0
  * syncArbitrateAddress(&val,ARBITRATION_WAIT_IF_LESS_THAN,0);
  * @endcode
+ *
+ * @note Usage of this function entails an implicit Data Memory Barrier (dmb).
  */
 Result syncArbitrateAddress(s32* addr, ArbitrationType type, s32 value);
 
@@ -160,6 +162,8 @@ Result syncArbitrateAddress(s32* addr, ArbitrationType type, s32 value);
  * // Thread will wait for a signal or wake up after 10000000 nanoseconds because val < 1.
  * syncArbitrateAddressWithTimeout(&val,ARBITRATION_WAIT_IF_LESS_THAN_TIMEOUT,1,10000000LL);
  * @endcode
+ *
+ * @note Usage of this function entails an implicit Data Memory Barrier (dmb).
  */
 Result syncArbitrateAddressWithTimeout(s32* addr, ArbitrationType type, s32 value, s64 timeout_ns);
 
diff --git a/libctru/source/svc.s b/libctru/source/svc.s
index 408f4d3..aa5c815 100644
--- a/libctru/source/svc.s
+++ b/libctru/source/svc.s
@@ -249,6 +249,11 @@ SVC_BEGIN svcArbitrateAddress
 	bx  lr
 SVC_END
 
+SVC_BEGIN svcArbitrateAddressNoTimeout
+	svc 0x22
+	bx  lr
+SVC_END
+
 SVC_BEGIN svcCloseHandle
 	svc 0x23
 	bx  lr
diff --git a/libctru/source/synchronization.c b/libctru/source/synchronization.c
index 65a387f..14b4f2e 100644
--- a/libctru/source/synchronization.c
+++ b/libctru/source/synchronization.c
@@ -18,7 +18,7 @@ void __sync_fini(void)
 
 Result syncArbitrateAddress(s32* addr, ArbitrationType type, s32 value)
 {
-	return svcArbitrateAddress(arbiter, (u32)addr, type, value, 0);
+	return svcArbitrateAddressNoTimeout(arbiter, (u32)addr, type, value);
 }
 
 Result syncArbitrateAddressWithTimeout(s32* addr, ArbitrationType type, s32 value, s64 timeout_ns)