Re: [dpdk-dev] [PATCH 03/11] lib: add armv8 rte_cpuflags.h

[Jan Viktorin <viktorin@rehivetech.com>]

On Fri, 23 Oct 2015 15:17:05 +0100
David Hunt <david.hunt@intel.com> wrote:

> +#include "generic/rte_cpuflags.h"
> +
> +/* Symbolic values for the entries in the auxiliary table */
> +#define AT_HWCAP  16
> +#define AT_HWCAP2 26
> +#define AT_PLATFORM 15
> +
> +/* software based registers */
> +enum cpu_register_t {
> +	REG_HWCAP = 0,
> +	AARCH_MODE,
> +};
> +
> +/**
> + * Enumeration of all CPU features supported
> + */
> +enum rte_cpu_flag_t {
> +	RTE_CPUFLAG_FP = 0,
> +	RTE_CPUFLAG_ASIMD,
> +	RTE_CPUFLAG_EVTSTRM,
> +	RTE_CPUFLAG_AARCH64,
> +	RTE_CPUFLAG_AARCH32,

We detect ARCH32/64 on both ARMv7 and ARMv8. This is strange.

> +	/* The last item */
> +	RTE_CPUFLAG_NUMFLAGS,/**< This should always be the last! */
> +};
> +
> +static const struct feature_entry cpu_feature_table[] = {
> +	FEAT_DEF(FP, 0x00000001, 0, REG_HWCAP,  0)
> +	FEAT_DEF(ASIMD, 0x00000001, 0, REG_HWCAP,  1)
> +	FEAT_DEF(EVTSTRM, 0x00000001, 0, REG_HWCAP,  2)
> +	FEAT_DEF(AARCH64, 0x00000001, 0, AARCH_MODE, 3)
> +	FEAT_DEF(AARCH32, 0x00000001, 0, AARCH_MODE, 4)
> +};
> +

Is it possible to extend it in the same way as it is prepared for ARMv7
[1, 2]?

[1] https://github.com/RehiveTech/dpdk/commit/bd5f0480b60282cfcd0ef43ddf8896bef8a23bbb
[2] https://github.com/RehiveTech/dpdk/commit/e293c11770aefc1f58f0c0cca5efee02b21910ba

Perhaps, can we merge this with ARMv7 one (in a single file)? Do the
features overlap in a sane way?

Jan


-- 
   Jan Viktorin                  E-mail: Viktorin@RehiveTech.com
   System Architect              Web:    www.RehiveTech.com
   RehiveTech
   Brno, Czech Republic