ART: Add FlushInstructionPipeline()

Use membarrier(MEMBARRIER_CMD_PRIVATE_EXPEDITED), where available, to
flush CPU instruction pipelines after JIT code cache updates. This is
needed on architectures where TLB updates do not require a TLB
shootdown.

Bug: 65312375
Bug: 66095511
Bug: 111199492
Test: manual (requires kernel >= 4.16).
Change-Id: I96811c611133ba765a546a09432c0c951ad39e10

1 files changed, 7 insertions, 4 deletions

diff --git a/libartbase/base/utils.h b/libartbase/base/utils.h
index ba61e1b0a3..44499415f8 100644
--- a/libartbase/base/utils.h
+++ b/libartbase/base/utils.h
@@ -179,16 +179,19 @@ static T GetRandomNumber(T min, T max) {
 // Sleep forever and never come back.
 NO_RETURN void SleepForever();
 
-inline void FlushInstructionCache(char* begin, char* end) {
-  __builtin___clear_cache(begin, end);
-}
-
 inline void FlushDataCache(char* begin, char* end) {
   // Same as FlushInstructionCache for lack of other builtin. __builtin___clear_cache
   // flushes both caches.
   __builtin___clear_cache(begin, end);
 }
 
+inline void FlushInstructionCache(char* begin, char* end) {
+  __builtin___clear_cache(begin, end);
+}
+
+// Flush instruction pipeline. Returns true on success, false if feature is unsupported.
+bool FlushInstructionPipeline();
+
 template <typename T>
 constexpr PointerSize ConvertToPointerSize(T any) {
   if (any == 4 || any == 8) {