[PATCH 1/6] eal: provide rte stdatomics optional atomics API

[Tyler Retzlaff]

Provide API for atomic operations in the rte namespace that may
optionally be configured to use C11 atomics with meson
option enable_stdatomics=true

Signed-off-by: Tyler Retzlaff <roretzla at linux.microsoft.com>
---
 config/meson.build              |   1 +
 config/rte_config.h             |   1 +
 lib/eal/include/meson.build     |   1 +
 lib/eal/include/rte_stdatomic.h | 162 ++++++++++++++++++++++++++++++++++++++++
 meson_options.txt               |   1 +
 5 files changed, 166 insertions(+)
 create mode 100644 lib/eal/include/rte_stdatomic.h

diff --git a/config/meson.build b/config/meson.build
index d822371..ec49964 100644
--- a/config/meson.build
+++ b/config/meson.build
@@ -303,6 +303,7 @@ endforeach
 # set other values pulled from the build options
 dpdk_conf.set('RTE_MAX_ETHPORTS', get_option('max_ethports'))
 dpdk_conf.set('RTE_LIBEAL_USE_HPET', get_option('use_hpet'))
+dpdk_conf.set('RTE_ENABLE_STDATOMIC', get_option('enable_stdatomic'))
 dpdk_conf.set('RTE_ENABLE_TRACE_FP', get_option('enable_trace_fp'))
 # values which have defaults which may be overridden
 dpdk_conf.set('RTE_MAX_VFIO_GROUPS', 64)
diff --git a/config/rte_config.h b/config/rte_config.h
index 400e44e..f17b6ae 100644
--- a/config/rte_config.h
+++ b/config/rte_config.h
@@ -13,6 +13,7 @@
 #define _RTE_CONFIG_H_
 
 #include <rte_build_config.h>
+#include <rte_stdatomic.h>
 
 /* legacy defines */
 #ifdef RTE_EXEC_ENV_LINUX
diff --git a/lib/eal/include/meson.build b/lib/eal/include/meson.build
index b0db9b3..f8a47b3 100644
--- a/lib/eal/include/meson.build
+++ b/lib/eal/include/meson.build
@@ -43,6 +43,7 @@ headers += files(
         'rte_seqlock.h',
         'rte_service.h',
         'rte_service_component.h',
+        'rte_stdatomic.h',
         'rte_string_fns.h',
         'rte_tailq.h',
         'rte_thread.h',
diff --git a/lib/eal/include/rte_stdatomic.h b/lib/eal/include/rte_stdatomic.h
new file mode 100644
index 0000000..832fd07
--- /dev/null
+++ b/lib/eal/include/rte_stdatomic.h
@@ -0,0 +1,162 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2023 Microsoft Corporation
+ */
+
+#ifndef _RTE_STDATOMIC_H_
+#define _RTE_STDATOMIC_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef int rte_memory_order;
+
+#ifdef RTE_ENABLE_STDATOMIC
+#ifdef __STDC_NO_ATOMICS__
+#error enable_stdatomics=true but atomics not supported by toolchain
+#endif
+
+#include <stdatomic.h>
+
+#define __rte_atomic _Atomic
+
+#define rte_memory_order_relaxed memory_order_relaxed
+#ifdef __ATOMIC_RELAXED
+_Static_assert(rte_memory_order_relaxed == __ATOMIC_RELAXED,
+	"rte_memory_order_relaxed == __ATOMIC_RELAXED");
+#endif
+
+#define rte_memory_order_consume memory_order_consume
+#ifdef __ATOMIC_CONSUME
+_Static_assert(rte_memory_order_consume == __ATOMIC_CONSUME,
+	"rte_memory_order_consume == __ATOMIC_CONSUME");
+#endif
+
+#define rte_memory_order_acquire memory_order_acquire
+#ifdef __ATOMIC_ACQUIRE
+_Static_assert(rte_memory_order_acquire == __ATOMIC_ACQUIRE,
+	"rte_memory_order_acquire == __ATOMIC_ACQUIRE");
+#endif
+
+#define rte_memory_order_release memory_order_release
+#ifdef __ATOMIC_RELEASE
+_Static_assert(rte_memory_order_release == __ATOMIC_RELEASE,
+	"rte_memory_order_release == __ATOMIC_RELEASE");
+#endif
+
+#define rte_memory_order_acq_rel memory_order_acq_rel
+#ifdef __ATOMIC_ACQ_REL
+_Static_assert(rte_memory_order_acq_rel == __ATOMIC_ACQ_REL,
+	"rte_memory_order_acq_rel == __ATOMIC_ACQ_REL");
+#endif
+
+#define rte_memory_order_seq_cst memory_order_seq_cst
+#ifdef __ATOMIC_SEQ_CST
+_Static_assert(rte_memory_order_seq_cst == __ATOMIC_SEQ_CST,
+	"rte_memory_order_seq_cst == __ATOMIC_SEQ_CST");
+#endif
+
+#define rte_atomic_load_explicit(ptr, memorder) \
+	atomic_load_explicit(ptr, memorder)
+
+#define rte_atomic_store_explicit(ptr, val, memorder) \
+	atomic_store_explicit(ptr, val, memorder)
+
+#define rte_atomic_exchange_explicit(ptr, val, memorder) \
+	atomic_exchange_explicit(ptr, val, memorder)
+
+#define rte_atomic_compare_exchange_strong_explicit( \
+	    ptr, expected, desired, succ_memorder, fail_memorder) \
+	atomic_compare_exchange_strong_explicit( \
+	    ptr, expected, desired, succ_memorder, fail_memorder)
+
+#define rte_atomic_compare_exchange_weak_explicit( \
+	    ptr, expected, desired, succ_memorder, fail_memorder) \
+	atomic_compare_exchange_strong_explicit( \
+	    ptr, expected, desired, succ_memorder, fail_memorder)
+
+#define rte_atomic_fetch_add_explicit(ptr, val, memorder) \
+	atomic_fetch_add_explicit(ptr, val, memorder)
+
+#define rte_atomic_fetch_sub_explicit(ptr, val, memorder) \
+	atomic_fetch_sub_explicit(ptr, val, memorder)
+
+#define rte_atomic_fetch_and_explicit(ptr, val, memorder) \
+	atomic_fetch_and_explicit(ptr, val, memorder)
+
+#define rte_atomic_fetch_xor_explicit(ptr, val, memorder) \
+	atomic_fetch_xor_explicit(ptr, val, memorder)
+
+#define rte_atomic_fetch_or_explicit(ptr, val, memorder) \
+	atomic_fetch_or_explicit(ptr, val, memorder)
+
+#define rte_atomic_fetch_nand_explicit(ptr, val, memorder) \
+	atomic_fetch_nand_explicit(ptr, val, memorder)
+
+#define rte_atomic_flag_test_and_set_explict(ptr, memorder) \
+	atomic_flag_test_and_set_explicit(ptr, memorder)
+
+#define rte_atomic_flag_clear_explicit(ptr, memorder) \
+	atomic_flag_clear(ptr, memorder)
+
+#else
+
+#define __rte_atomic
+
+#define rte_memory_order_relaxed __ATOMIC_RELAXED
+#define rte_memory_order_consume __ATOMIC_CONSUME
+#define rte_memory_order_acquire __ATOMIC_ACQUIRE
+#define rte_memory_order_release __ATOMIC_RELEASE
+#define rte_memory_order_acq_rel __ATOMIC_ACQ_REL
+#define rte_memory_order_seq_cst __ATOMIC_SEQ_CST
+
+#define rte_atomic_load_explicit(ptr, memorder) \
+	__atomic_load_n(ptr, memorder)
+
+#define rte_atomic_store_explicit(ptr, val, memorder) \
+	__atomic_store_n(ptr, val, memorder)
+
+#define rte_atomic_exchange_explicit(ptr, val, memorder) \
+	__atomic_exchange_n(ptr, val, memorder)
+
+#define rte_atomic_compare_exchange_strong_explicit( \
+	    ptr, expected, desired, succ_memorder, fail_memorder) \
+	__atomic_compare_exchange_n( \
+	    ptr, expected, desired, 0, succ_memorder, fail_memorder)
+
+#define rte_atomic_compare_exchange_weak_explicit( \
+	    ptr, expected, desired, succ_memorder, fail_memorder) \
+	__atomic_compare_exchange_n( \
+	    ptr, expected, desired, 1, succ_memorder, fail_memorder)
+
+#define rte_atomic_fetch_add_explicit(ptr, val, memorder) \
+	__atomic_fetch_add(ptr, val, memorder)
+
+#define rte_atomic_fetch_sub_explicit(ptr, val, memorder) \
+	__atomic_fetch_sub(ptr, val, memorder)
+
+#define rte_atomic_fetch_and_explicit(ptr, val, memorder) \
+	__atomic_fetch_and(ptr, val, memorder)
+
+#define rte_atomic_fetch_xor_explicit(ptr, val, memorder) \
+	__atomic_fetch_xor(ptr, val, memorder)
+
+#define rte_atomic_fetch_or_explicit(ptr, val, memorder) \
+	__atomic_fetch_or(ptr, val, memorder)
+
+#define rte_atomic_fetch_nand_explicit(ptr, val, memorder) \
+	__atomic_fetch_nand(ptr, val, memorder)
+
+#define rte_atomic_flag_test_and_set_explicit(ptr, memorder) \
+	__atomic_test_and_set(ptr, memorder)
+
+#define rte_atomic_flag_clear_explicit(ptr, memorder) \
+	__atomic_clear(ptr, memorder)
+
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _RTE_STDATOMIC_H_ */
diff --git a/meson_options.txt b/meson_options.txt
index 621e1ca..7d6784d 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -46,6 +46,7 @@ option('mbuf_refcnt_atomic', type: 'boolean', value: true, description:
        'Atomically access the mbuf refcnt.')
 option('platform', type: 'string', value: 'native', description:
        'Platform to build, either "native", "generic" or a SoC. Please refer to the Linux build guide for more information.')
+option('enable_stdatomic', type: 'boolean', value: false, description: 'enable use of C11 stdatomic')
 option('enable_trace_fp', type: 'boolean', value: false, description:
        'enable fast path trace points.')
 option('tests', type: 'boolean', value: true, description:
-- 
1.8.3.1