[PATCH v2 1/7] ring: replace rte atomics with GCC builtin atomics

[Tyler Retzlaff <roretzla@linux.microsoft.com>]

Replace the use of rte_atomic.h types and functions, instead use GCC
supplied C++11 memory model builtins.

Signed-off-by: Tyler Retzlaff <roretzla@linux.microsoft.com>
---
 lib/ring/rte_ring_core.h        |  1 -
 lib/ring/rte_ring_generic_pvt.h | 12 ++++++++----
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/lib/ring/rte_ring_core.h b/lib/ring/rte_ring_core.h
index 82b2370..b9c7860 100644
--- a/lib/ring/rte_ring_core.h
+++ b/lib/ring/rte_ring_core.h
@@ -31,7 +31,6 @@
 #include <rte_config.h>
 #include <rte_memory.h>
 #include <rte_lcore.h>
-#include <rte_atomic.h>
 #include <rte_branch_prediction.h>
 #include <rte_memzone.h>
 #include <rte_pause.h>
diff --git a/lib/ring/rte_ring_generic_pvt.h b/lib/ring/rte_ring_generic_pvt.h
index 5acb6e5..c284040 100644
--- a/lib/ring/rte_ring_generic_pvt.h
+++ b/lib/ring/rte_ring_generic_pvt.h
@@ -92,8 +92,10 @@
 		if (is_sp)
 			r->prod.head = *new_head, success = 1;
 		else
-			success = rte_atomic32_cmpset(&r->prod.head,
-					*old_head, *new_head);
+			// NOTE: review for potential ordering optimization
+			success = __atomic_compare_exchange_n(&r->prod.head,
+					old_head, *new_head, 0,
+					__ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST);
 	} while (unlikely(success == 0));
 	return n;
 }
@@ -162,8 +164,10 @@
 			rte_smp_rmb();
 			success = 1;
 		} else {
-			success = rte_atomic32_cmpset(&r->cons.head, *old_head,
-					*new_head);
+			// NOTE: review for potential ordering optimization
+			success = __atomic_compare_exchange_n(&r->cons.head,
+					old_head, *new_head, 0,
+					__ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST);
 		}
 	} while (unlikely(success == 0));
 	return n;
-- 
1.8.3.1