eal: introduce bit operations API

Bitwise operation APIs are defined and used in a lot of PMDs,
which caused a huge code duplication. To reduce duplication,
this patch consolidates them into a common API family.

Signed-off-by: Joyce Kong <joyce.kong@arm.com>
Reviewed-by: Gavin Hu <gavin.hu@arm.com>
Reviewed-by: Phil Yang <phil.yang@arm.com>
Acked-by: Morten Brørup <mb@smartsharesystems.com>

MAINTAINERS

@@ -246,6 +246,10 @@ F: lib/librte_eal/common/rte_service.c
 F: doc/guides/prog_guide/service_cores.rst
 F: app/test/test_service_cores.c
 
+Bitops
+M: Joyce Kong <joyce.kong@arm.com>
+F: lib/librte_eal/include/rte_bitops.h
+
 Bitmap
 M: Cristian Dumitrescu <cristian.dumitrescu@intel.com>
 F: lib/librte_eal/include/rte_bitmap.h

doc/api/doxy-api-index.md

@@ -166,6 +166,7 @@ The public API headers are grouped by topics:
     [ip4_node]         (@ref rte_node_ip4_api.h)
 
 - **basic**:
+  [bitops]             (@ref rte_bitops.h),
   [approx fraction]    (@ref rte_approx.h),
   [random]             (@ref rte_random.h),
   [config file]        (@ref rte_cfgfile.h),

lib/librte_eal/include/meson.build

@@ -6,6 +6,7 @@ includes += include_directories('.')
 headers += files(
 	'rte_alarm.h',
 	'rte_bitmap.h',
+	'rte_bitops.h',
 	'rte_branch_prediction.h',
 	'rte_bus.h',
 	'rte_class.h',

lib/librte_eal/include/rte_bitops.h

@@ -0,0 +1,258 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2020 Arm Limited
+ */
+
+#ifndef _RTE_BITOPS_H_
+#define _RTE_BITOPS_H_
+
+/**
+ * @file
+ * Bit Operations
+ *
+ * This file defines a family of APIs for bit operations
+ * without enforcing memory ordering.
+ */
+
+#include <stdint.h>
+#include <rte_debug.h>
+#include <rte_compat.h>
+
+/*------------------------ 32-bit relaxed operations ------------------------*/
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change, or be removed, without prior notice
+ *
+ * Get the target bit from a 32-bit value without memory ordering.
+ *
+ * @param nr
+ *   The target bit to get.
+ * @param addr
+ *   The address holding the bit.
+ * @return
+ *   The target bit.
+ */
+__rte_experimental
+static inline uint32_t
+rte_bit_relaxed_get32(unsigned int nr, volatile uint32_t *addr)
+{
+	RTE_ASSERT(nr < 32);
+
+	uint32_t mask = UINT32_C(1) << nr;
+	return (*addr) & mask;
+}
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change, or be removed, without prior notice
+ *
+ * Set the target bit in a 32-bit value to 1 without memory ordering.
+ *
+ * @param nr
+ *   The target bit to set.
+ * @param addr
+ *   The address holding the bit.
+ */
+__rte_experimental
+static inline void
+rte_bit_relaxed_set32(unsigned int nr, volatile uint32_t *addr)
+{
+	RTE_ASSERT(nr < 32);
+
+	uint32_t mask = UINT32_C(1) << nr;
+	*addr = (*addr) | mask;
+}
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change, or be removed, without prior notice
+ *
+ * Clear the target bit in a 32-bit value to 0 without memory ordering.
+ *
+ * @param nr
+ *   The target bit to clear.
+ * @param addr
+ *   The address holding the bit.
+ */
+__rte_experimental
+static inline void
+rte_bit_relaxed_clear32(unsigned int nr, volatile uint32_t *addr)
+{
+	RTE_ASSERT(nr < 32);
+
+	uint32_t mask = UINT32_C(1) << nr;
+	*addr = (*addr) & (~mask);
+}
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change, or be removed, without prior notice
+ *
+ * Return the original bit from a 32-bit value, then set it to 1 without
+ * memory ordering.
+ *
+ * @param nr
+ *   The target bit to get and set.
+ * @param addr
+ *   The address holding the bit.
+ * @return
+ *   The original bit.
+ */
+__rte_experimental
+static inline uint32_t
+rte_bit_relaxed_test_and_set32(unsigned int nr, volatile uint32_t *addr)
+{
+	RTE_ASSERT(nr < 32);
+
+	uint32_t mask = UINT32_C(1) << nr;
+	uint32_t val = *addr;
+	*addr = val | mask;
+	return val & mask;
+}
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change, or be removed, without prior notice
+ *
+ * Return the original bit from a 32-bit value, then clear it to 0 without
+ * memory ordering.
+ *
+ * @param nr
+ *   The target bit to get and clear.
+ * @param addr
+ *   The address holding the bit.
+ * @return
+ *   The original bit.
+ */
+__rte_experimental
+static inline uint32_t
+rte_bit_relaxed_test_and_clear32(unsigned int nr, volatile uint32_t *addr)
+{
+	RTE_ASSERT(nr < 32);
+
+	uint32_t mask = UINT32_C(1) << nr;
+	uint32_t val = *addr;
+	*addr = val & (~mask);
+	return val & mask;
+}
+
+/*------------------------ 64-bit relaxed operations ------------------------*/
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change, or be removed, without prior notice
+ *
+ * Get the target bit from a 64-bit value without memory ordering.
+ *
+ * @param nr
+ *   The target bit to get.
+ * @param addr
+ *   The address holding the bit.
+ * @return
+ *   The target bit.
+ */
+__rte_experimental
+static inline uint64_t
+rte_bit_relaxed_get64(unsigned int nr, volatile uint64_t *addr)
+{
+	RTE_ASSERT(nr < 64);
+
+	uint64_t mask = UINT64_C(1) << nr;
+	return (*addr) & mask;
+}
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change, or be removed, without prior notice
+ *
+ * Set the target bit in a 64-bit value to 1 without memory ordering.
+ *
+ * @param nr
+ *   The target bit to set.
+ * @param addr
+ *   The address holding the bit.
+ */
+__rte_experimental
+static inline void
+rte_bit_relaxed_set64(unsigned int nr, volatile uint64_t *addr)
+{
+	RTE_ASSERT(nr < 64);
+
+	uint64_t mask = UINT64_C(1) << nr;
+	(*addr) = (*addr) | mask;
+}
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change, or be removed, without prior notice
+ *
+ * Clear the target bit in a 64-bit value to 0 without memory ordering.
+ *
+ * @param nr
+ *   The target bit to clear.
+ * @param addr
+ *   The address holding the bit.
+ */
+__rte_experimental
+static inline void
+rte_bit_relaxed_clear64(unsigned int nr, volatile uint64_t *addr)
+{
+	RTE_ASSERT(nr < 64);
+
+	uint64_t mask = UINT64_C(1) << nr;
+	*addr = (*addr) & (~mask);
+}
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change, or be removed, without prior notice
+ *
+ * Return the original bit from a 64-bit value, then set it to 1 without
+ * memory ordering.
+ *
+ * @param nr
+ *   The target bit to get and set.
+ * @param addr
+ *   The address holding the bit.
+ * @return
+ *   The original bit.
+ */
+__rte_experimental
+static inline uint64_t
+rte_bit_relaxed_test_and_set64(unsigned int nr, volatile uint64_t *addr)
+{
+	RTE_ASSERT(nr < 64);
+
+	uint64_t mask = UINT64_C(1) << nr;
+	uint64_t val = *addr;
+	*addr = val | mask;
+	return val;
+}
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change, or be removed, without prior notice
+ *
+ * Return the original bit from a 64-bit value, then clear it to 0 without
+ * memory ordering.
+ *
+ * @param nr
+ *   The target bit to get and clear.
+ * @param addr
+ *   The address holding the bit.
+ * @return
+ *   The original bit.
+ */
+__rte_experimental
+static inline uint64_t
+rte_bit_relaxed_test_and_clear64(unsigned int nr, volatile uint64_t *addr)
+{
+	RTE_ASSERT(nr < 64);
+
+	uint64_t mask = UINT64_C(1) << nr;
+	uint64_t val = *addr;
+	*addr = val & (~mask);
+	return val & mask;
+}
+
+#endif /* _RTE_BITOPS_H_ */