Re: [PATCH] [RFC] cryptodev: replace LIST_END enumerators with APIs

[Ferruh Yigit <ferruh.yigit@amd.com>]

On 9/23/2024 9:41 PM, Akhil Goyal wrote:
> Hi Morten,
> 
> Apologies for delayed response.
>> Maybe a combination, returning the lowest end of the two versions of the list,
>> would work...
>>
>> ----------------------------------
>> Common header file (rte_common.h):
>> ----------------------------------
>>
>> /* Add at end of enum list in the header file. */
>> #define RTE_ENUM_LIST_END(name) \
>> _ # name # _ENUM_LIST_END /**< @internal */
>>
>> /* Add somewhere in header file, preferably after the enum list. */
>> #define rte_declare_enum_list_end(name) \
>> /** @internal */ \
>> int _# name # _enum_list_end(void); \
>> \
>> static int name # _enum_list_end(void) \
>> { \
>> 	static int cached = 0; \
>> \
>> 	if (likely(cached != 0)) \
>> 		return cached; \
>> \
>> 	return cached = RTE_MIN( \
>> 			RTE_ENUM_LIST_END(name), \
>> 			_ # name # _enum_list_end()); \
>> } \
>> \
>> int _# name # _enum_list_end(void)
>>
>> /* Add in the library/driver implementation. */
>> #define rte_define_enum_list_end(name) \
>> int _# name # _enum_list_end(void) \
>> { \
>> 	return RTE_ENUM_LIST_END(name); \
>> } \
>> \
>> int _# name # _enum_list_end(void)
>>
>> --------------------
>> Library header file:
>> --------------------
>>
>> enum rte_crypto_asym_op_type {
>> 	RTE_CRYPTO_ASYM_OP_VERIFY,
>> 	/**< Signature Verification operation */
>> 	RTE_ENUM_LIST_END(rte_crypto_asym_op)
> 
> Will the ABI check be ok for adding anything in between 
> RTE_CRYPTO_ASYM_OP_VERIFY and RTE_ENUM_LIST_END(rte_crypto_asym_op)?
> Don’t we need to add exception for that if we somehow make it internal by adding a comment only?
> Library is actually not restricting the application to not use RTE_ENUM_LIST_END(rte_crypto_asym_op) directly.
> 
> Also we may need to expose the .c file internal function as experimental in version.map
> 
>> }
>>
>> rte_declare_enum_list_end(rte_crypto_asym_op);
>>
>> ---------------
>> Library C file:
>> ---------------
>>
>> rte_define_enum_list_end(rte_crypto_asym_op);
> 
> If we want to make it a generic thing in rte_common.h
> Will the below change be ok?
> ----------------------------------
> Common header file (rte_common.h):
> ----------------------------------
> #define rte_define_enum_list_end(name, last_value) \
> static inline int name ## _enum_list_end(void) \
> { \
>        return last_value + 1; \
> }
> 
> ----------------
> Lib header file
> ----------------
> //After the enum definition define the list end as below
> rte_define_enum_list_end(rte_crypto_asym_op, RTE_CRYPTO_ASYM_OP_VERIFY);
> 

I assume Morten suggests his macros to escape from maintenance cost of
updating inline function each time a new enum is added.

But with above suggestion, that cost is still there, so I don't think
this one has a benefit against the original suggestion.