Re: [PATCH iwl-net] ice: fix ice_parser_rt::bst_key array size

[Przemek Kitszel <przemyslaw.kitszel@intel.com>]

On 12/12/24 17:30, Simon Horman wrote:
> On Wed, Dec 11, 2024 at 02:26:36PM +0100, Przemek Kitszel wrote:
>> Fix &ice_parser_rt::bst_key size. It was wrongly set to 10 instead of 20
>> in the initial impl commit (see Fixes tag). All usage code assumed it was
>> of size 20. That was also the initial size present up to v2 of the intro
>> series [2], but halved by v3 [3] refactor described as "Replace magic
>> hardcoded values with macros." The introducing series was so big that
>> some ugliness was unnoticed, same for bugs :/
>>
>> ICE_BST_KEY_TCAM_SIZE and ICE_BST_TCAM_KEY_SIZE were differing by one.
>> There was tmp variable @j in the scope of edited function, but was not
>> used in all places. This ugliness is now gone.
>> I'm moving ice_parser_rt::pg_prio a few positions up, to fill up one of
>> the holes in order to compensate for the added 10 bytes to the ::bst_key,
>> resulting in the same size of the whole as prior to the fix, and miminal
>> changes in the offsets of the fields.
>>
>> This fix obsoletes Ahmed's attempt at [1].
>>
>> [1] https://lore.kernel.org/intel-wired-lan/20240823230847.172295-1-ahmed.zaki@intel.com
>> [2] https://lore.kernel.org/intel-wired-lan/20230605054641.2865142-13-junfeng.guo@intel.com
>> [3] https://lore.kernel.org/intel-wired-lan/20230817093442.2576997-13-junfeng.guo@intel.com
>>
>> Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
>> Closes: https://lore.kernel.org/intel-wired-lan/b1fb6ff9-b69e-4026-9988-3c783d86c2e0@stanley.mountain
>> Fixes: 9a4c07aaa0f5 ("ice: add parser execution main loop")
>> CC: Ahmed Zaki <ahmed.zaki@intel.com>
>> Reviewed-by: Larysa Zaremba <larysa.zaremba@intel.com>
>> Signed-off-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
> 
> Hi Przemek,
> 
> I agree that these changes are good.  But I wonder if it would be best to
> only treat the update size of bst_key as a fix.

I was also wondering, to the point that my first version was with
all 20 key bytes debug-printed in the exact way as it was prior to the
patch. Would be fine to just drop the printing part?

> 
> ...
> 
>> diff --git a/drivers/net/ethernet/intel/ice/ice_parser_rt.c b/drivers/net/ethernet/intel/ice/ice_parser_rt.c
>> index dedf5e854e4b..d9c38ce27e4f 100644
>> --- a/drivers/net/ethernet/intel/ice/ice_parser_rt.c
>> +++ b/drivers/net/ethernet/intel/ice/ice_parser_rt.c
>> @@ -125,22 +125,20 @@ static void ice_bst_key_init(struct ice_parser_rt *rt,
>>   	else
>>   		key[idd] = imem->b_kb.prio;
>>   
>> -	idd = ICE_BST_KEY_TCAM_SIZE - 1;
>> +	idd = ICE_BST_TCAM_KEY_SIZE - 2;
>>   	for (i = idd; i >= 0; i--) {
>>   		int j;
>>   
>>   		j = ho + idd - i;
>>   		if (j < ICE_PARSER_MAX_PKT_LEN)
>> -			key[i] = rt->pkt_buf[ho + idd - i];
>> +			key[i] = rt->pkt_buf[j];
>>   		else
>>   			key[i] = 0;
>>   	}
>>   
>> -	ice_debug(rt->psr->hw, ICE_DBG_PARSER, "Generated Boost TCAM Key:\n");
>> -	ice_debug(rt->psr->hw, ICE_DBG_PARSER, "%02X %02X %02X %02X %02X %02X %02X %02X %02X %02X\n",
>> -		  key[0], key[1], key[2], key[3], key[4],
>> -		  key[5], key[6], key[7], key[8], key[9]);
>> -	ice_debug(rt->psr->hw, ICE_DBG_PARSER, "\n");
>> +	ice_debug_array_w_prefix(rt->psr->hw, ICE_DBG_PARSER,
>> +				 KBUILD_MODNAME "Generated Boost TCAM Key",
> 
> Should there be a delimeter between KBUILD_MODNAME and "Generated ..." ?
> e.g.:

thank you :)

> 
> 				 KBUILD_MODNAME ": Generated Boost TCAM Key",
> 
>> +				 key, ICE_BST_TCAM_KEY_SIZE);
>>   }
>>   
>>   static u16 ice_bit_rev_u16(u16 v, int len)
>>
>> base-commit: 51a00be6a0994da2ba6b4ace3b7a0d9373b4b25e
>> -- 
>> 2.46.0
>>
>>