summaryrefslogtreecommitdiff
path: root/scripts/atomic/fallbacks/dec_if_positive
diff options
context:
space:
mode:
authorIngo Molnar <mingo@kernel.org>2019-02-11 14:27:05 +0100
committerIngo Molnar <mingo@kernel.org>2019-02-11 14:27:05 +0100
commit41b8687191cfd0326db03b0e82fb09d8c98ca641 (patch)
treea214babca0a181c67c25a615d608465a5f92f8c4 /scripts/atomic/fallbacks/dec_if_positive
parent49262de2270e09882d7bd8866a691cdd69ab32f6 (diff)
parentbdf37b4dd35d2517cadc10735cd33022da7df133 (diff)
Merge branch 'locking/atomics' into locking/core, to pick up WIP commits
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'scripts/atomic/fallbacks/dec_if_positive')
-rwxr-xr-xscripts/atomic/fallbacks/dec_if_positive15
1 files changed, 15 insertions, 0 deletions
diff --git a/scripts/atomic/fallbacks/dec_if_positive b/scripts/atomic/fallbacks/dec_if_positive
new file mode 100755
index 000000000000..c52eacec43c8
--- /dev/null
+++ b/scripts/atomic/fallbacks/dec_if_positive
@@ -0,0 +1,15 @@
+cat <<EOF
+static inline ${ret}
+${atomic}_dec_if_positive(${atomic}_t *v)
+{
+ ${int} dec, c = ${atomic}_read(v);
+
+ do {
+ dec = c - 1;
+ if (unlikely(dec < 0))
+ break;
+ } while (!${atomic}_try_cmpxchg(v, &c, dec));
+
+ return dec;
+}
+EOF