tile: support atomic64_dec_if_positive()
Use the normal cmpxchg() idiom to implement this functionality.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
diff --git a/arch/tile/Kconfig b/arch/tile/Kconfig
index 0e500d9..9a9d086 100644
--- a/arch/tile/Kconfig
+++ b/arch/tile/Kconfig
@@ -24,6 +24,7 @@
select MODULES_USE_ELF_RELA
select HAVE_ARCH_TRACEHOOK
select HAVE_SYSCALL_TRACEPOINTS
+ select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
# FIXME: investigate whether we need/want these options.
# select HAVE_IOREMAP_PROT