[dpdk-dev] [RFC PATCH] config: remap flags used for Arm platforms

[Bruce Richardson]

On Fri, Aug 14, 2020 at 02:03:20PM +0800, Ruifeng Wang wrote:
> Flags are used to distinguish different platform architectures.
> These flags can be used to pick different code paths for different
> architectures at compile time.
> For Arm platforms, there are 3 flags in use: RTE_ARCH_ARM,
> RTE_ARCH_ARMv7 and RTE_ARCH_ARM64.
> RTE_ARCH_ARM64 is used to flag 64-bit aarch64 platforms,
> while RTE_ARCH_ARM & RTE_ARCH_ARMv7 are used to flag 32-bit platforms.
> RTE_ARCH_ARMv7 is for ARMv7 platforms as its name suggested.
> 
> The issue is that flag name RTE_ARCH_ARM is unclear and could cause
> confusion. No info about platform word length is included in the name.
> To make the flag names more clear, a naming scheme is proposed.
> 
>       RTE_ARCH_ARM
>           |
>           +----RTE_ARCH_ARM32
>           |        |
>           |        +----RTE_ARCH_ARMv7
>           |        |
>           |        +----RTE_ARCH_ARMv8_AARCH32
>           |
>           +----RTE_ARCH_ARM64
> 
> RTE_ARCH_ARM32 will be used for 32-bit Arm platforms.
> It includes RTE_ARCH_ARMv7 and RTE_ARCH_ARMv8_AARCH32.
> RTE_ARCH_ARMv7 is for ARMv7 platforms.
> RTE_ARCH_ARMv8_AARCH32 is for aarch32 state on aarch64 platforms.
> RTE_ARCH_ARM64 is for 64-bit Arm platforms.
> RTE_ARCH_ARM will be used for all Arm platforms, including RTE_ARCH_ARM32
> and RTE_ARCH_ARM64.
> 
> To fit into the new naming scheme, current usage of RTE_ARCH_ARM in
> project code is mapped to RTE_ARCH_ARM32.
> 
> Suggested-by: Honnappa Nagarahalli <honnappa.nagarahalli at arm.com>
> Signed-off-by: Ruifeng Wang <ruifeng.wang at arm.com>
> Reviewed-by: Phil Yang <phil.yang at arm.com>
> ---
Just to note that for all architectures there is the RTE_ARCH_64 define
which is set if the system is 64-bit. That could be used instead if you
didn't want to have to specially define ARM32 and ARM64 macros.

/Bruce