vppinfra: add atomic macros for __sync builtins

This is first part of addition of atomic macros with only macros for
__sync builtins.

- Based on earlier patch by Damjan (https://gerrit.fd.io/r/#/c/10729/)
Additionally
- clib_atomic_release macro added and used in the absence
of any memory barrier.
- clib_atomic_bool_cmp_and_swap added

Change-Id: Ie4e48c1e184a652018d1d0d87c4be80ddd180a3b
Original-patch-by: Damjan Marion <damarion@cisco.com>
Signed-off-by: Sirshak Das <sirshak.das@arm.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Reviewed-by: Ola Liljedahl <ola.liljedahl@arm.com>
Reviewed-by: Steve Capper <steve.capper@arm.com>

4 files changed, 11 insertions, 11 deletions

diff --git a/src/svm/message_queue.c b/src/svm/message_queue.c
index a73a56d8044..13d089a97cc 100644
--- a/src/svm/message_queue.c
+++ b/src/svm/message_queue.c
@@ -108,7 +108,7 @@ svm_msg_q_alloc_msg_w_ring (svm_msg_q_t * mq, u32 ring_index)
   msg.ring_index = ring - mq->rings;
   msg.elt_index = ring->tail;
   ring->tail = (ring->tail + 1) % ring->nitems;
-  __sync_fetch_and_add (&ring->cursize, 1);
+  clib_atomic_fetch_add (&ring->cursize, 1);
   return msg;
 }
 
@@ -155,7 +155,7 @@ svm_msg_q_alloc_msg (svm_msg_q_t * mq, u32 nbytes)
     msg.ring_index = ring - mq->rings;
     msg.elt_index = ring->tail;
     ring->tail = (ring->tail + 1) % ring->nitems;
-    __sync_fetch_and_add (&ring->cursize, 1);
+    clib_atomic_fetch_add (&ring->cursize, 1);
     break;
   }
   return msg;
@@ -185,7 +185,7 @@ svm_msg_q_free_msg (svm_msg_q_t * mq, svm_msg_q_msg_t * msg)
       /* for now, expect messages to be processed in order */
       ASSERT (0);
     }
-  __sync_fetch_and_sub (&ring->cursize, 1);
+  clib_atomic_fetch_sub (&ring->cursize, 1);
 }
 
 static int
diff --git a/src/svm/ssvm.h b/src/svm/ssvm.h
index 8677f5680be..5b2bf0d202d 100644
--- a/src/svm/ssvm.h
+++ b/src/svm/ssvm.h
@@ -103,7 +103,7 @@ ssvm_lock (ssvm_shared_header_t * h, u32 my_pid, u32 tag)
       return;
     }
 
-  while (__sync_lock_test_and_set (&h->lock, 1))
+  while (clib_atomic_test_and_set (&h->lock))
     ;
 
   h->owner_pid = my_pid;
@@ -114,7 +114,7 @@ ssvm_lock (ssvm_shared_header_t * h, u32 my_pid, u32 tag)
 always_inline void
 ssvm_lock_non_recursive (ssvm_shared_header_t * h, u32 tag)
 {
-  while (__sync_lock_test_and_set (&h->lock, 1))
+  while (clib_atomic_test_and_set (&h->lock))
     ;
 
   h->tag = tag;
diff --git a/src/svm/svm_fifo.c b/src/svm/svm_fifo.c
index 4eae0a1c7e6..aa523c6b55c 100644
--- a/src/svm/svm_fifo.c
+++ b/src/svm/svm_fifo.c
@@ -513,7 +513,7 @@ CLIB_MARCH_FN (svm_fifo_enqueue_nowait, int, svm_fifo_t * f, u32 max_bytes,
 
   /* Atomically increase the queue length */
   ASSERT (cursize + total_copy_bytes <= nitems);
-  __sync_fetch_and_add (&f->cursize, total_copy_bytes);
+  clib_atomic_fetch_add (&f->cursize, total_copy_bytes);
 
   return (total_copy_bytes);
 }
@@ -659,7 +659,7 @@ CLIB_MARCH_FN (svm_fifo_dequeue_nowait, int, svm_fifo_t * f, u32 max_bytes,
 
   ASSERT (f->head <= nitems);
   ASSERT (cursize >= total_copy_bytes);
-  __sync_fetch_and_sub (&f->cursize, total_copy_bytes);
+  clib_atomic_fetch_sub (&f->cursize, total_copy_bytes);
 
   return (total_copy_bytes);
 }
@@ -757,7 +757,7 @@ svm_fifo_dequeue_drop (svm_fifo_t * f, u32 max_bytes)
 
   ASSERT (f->head <= nitems);
   ASSERT (cursize >= total_drop_bytes);
-  __sync_fetch_and_sub (&f->cursize, total_drop_bytes);
+  clib_atomic_fetch_sub (&f->cursize, total_drop_bytes);
 
   return total_drop_bytes;
 }
@@ -766,7 +766,7 @@ void
 svm_fifo_dequeue_drop_all (svm_fifo_t * f)
 {
   f->head = f->tail;
-  __sync_fetch_and_sub (&f->cursize, f->cursize);
+  clib_atomic_fetch_sub (&f->cursize, f->cursize);
 }
 
 int
@@ -813,7 +813,7 @@ svm_fifo_segments_free (svm_fifo_t * f, svm_fifo_segment_t * fs)
       f->head = (f->head + fs[0].len) % f->nitems;
       total_drop_bytes = fs[0].len;
     }
-  __sync_fetch_and_sub (&f->cursize, total_drop_bytes);
+  clib_atomic_fetch_sub (&f->cursize, total_drop_bytes);
 }
 
 u32
diff --git a/src/svm/svm_fifo.h b/src/svm/svm_fifo.h
index d7852a79b32..e049d3e3147 100644
--- a/src/svm/svm_fifo.h
+++ b/src/svm/svm_fifo.h
@@ -169,7 +169,7 @@ svm_fifo_set_event (svm_fifo_t * f)
 always_inline void
 svm_fifo_unset_event (svm_fifo_t * f)
 {
-  __sync_lock_release (&f->has_event);
+  clib_atomic_release (&f->has_event);
 }
 
 static inline void