[RFC v2 5/6] eal: add atomic bit operations

[Morten Brørup]

> +#define rte_bit_atomic_test(addr, nr, memory_order)			\
> +	_Generic((addr),						\
> +		 uint32_t *: __rte_bit_atomic_test32,			\
> +		 uint64_t *: __rte_bit_atomic_test64)(addr, nr, memory_order)

I wonder if these should have RTE_ATOMIC qualifier:

+		 RTE_ATOMIC(uint32_t) *: __rte_bit_atomic_test32,			\
+		 RTE_ATOMIC(uint64_t) *: __rte_bit_atomic_test64)(addr, nr, memory_order)


> +#define __RTE_GEN_BIT_ATOMIC_TEST(size)					\
> +	static inline bool						\
> +	__rte_bit_atomic_test ## size(const uint ## size ## _t *addr,	\

I wonder if the "addr" parameter should have RTE_ATOMIC qualifier:

+	__rte_bit_atomic_test ## size(const RTE_ATOMIC(uint ## size ## _t) *addr,	\

instead of casting into a_addr.

> +				      unsigned int nr, int memory_order) \
> +	{								\
> +		RTE_ASSERT(nr < size);					\
> +									\
> +		const RTE_ATOMIC(uint ## size ## _t) *a_addr =		\
> +			(const RTE_ATOMIC(uint ## size ## _t) *)addr;	\
> +		uint ## size ## _t mask = (uint ## size ## _t)1 << nr;	\
> +		return rte_atomic_load_explicit(a_addr, memory_order) & mask; \
> +	}


Similar considerations regarding volatile qualifier for the "once" operations.