From: Andrei Tatar <andrei@unikraft.io>
Date: Tue, 7 Nov 2023 13:53:45 +0000 (+0100)
Subject: include/arch: Add raw compare-exchange operation
X-Git-Tag: RELEASE-0.16.0~203
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=4a48944275b4fd28a996c06419616df304fb5bb1;p=unikraft%2Funikraft.git

include/arch: Add raw compare-exchange operation

This change adds a Unikraft macro for the raw compare-exchange
operation, which in contrast to the existing macro may modify its
arguments.

Signed-off-by: Andrei Tatar <andrei@unikraft.io>
Reviewed-by: Simon Kuenzer <simon@unikraft.io>
Approved-by: Simon Kuenzer <simon@unikraft.io>
GitHub-Closes: #1156
---

diff --git a/include/uk/arch/atomic.h b/include/uk/arch/atomic.h
index 2350b5d27..f03f1e692 100644
--- a/include/uk/arch/atomic.h
+++ b/include/uk/arch/atomic.h
@@ -93,6 +93,10 @@ extern "C" {
 #define ukarch_exchange_n(dst, v) \
 	__atomic_exchange_n(dst, v, __ATOMIC_SEQ_CST)
 
+#define ukarch_compare_exchange_n(dst, exp, des)  \
+	__atomic_compare_exchange_n(dst, exp, des, 0, \
+	                            __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)
+
 #define ukarch_compare_exchange_sync(ptr, old, new)                            \
 	({                                                                     \
 		__typeof__(*ptr) stored = old;                                 \