Re: [PATCH net-next v4 05/18] net/smc: reserve CHID range for SMC-D virtual device

[Alexandra Winter <wintera@linux.ibm.com>]

On 28.09.23 05:08, Jan Karcher wrote:
> On 24/09/2023 17:16, Wen Gu wrote:
>> This patch reserve CHID range from 0xFF00 to 0xFFFF for SMC-D virtual
> 
> The current state is that 0xFF00 - 0xFFFF is the range of all virtual SMC-D devices. This range devides into:
> - 0xFF00 - 0xFFFE is for virto-ism
> - 0xFFFF is for loopback
> 
> 
>> device and introduces helpers to identify them.
>>
>> Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
>> ---
>>   net/smc/smc_ism.h | 15 +++++++++++++++
>>   1 file changed, 15 insertions(+)
>>
>> diff --git a/net/smc/smc_ism.h b/net/smc/smc_ism.h
>> index 14d2e77..2ecc8de 100644
>> --- a/net/smc/smc_ism.h
>> +++ b/net/smc/smc_ism.h
>> @@ -15,6 +15,9 @@
>>     #include "smc.h"
>>   +#define SMC_VIRT_ISM_CHID_MAX        0xFFFF
> 
> SMC_VIRT_ISM_MAX is 0xFFFE. Or do you mean virtual devices as the whole group. If yes i think that this naming will be very confusing in a few months/years.
> Maybe something like SMC_VIRTUAL_DEV_CHID_{MIN|MAX}?


IMO names are important. They can make future lives easier or harder.

Your first group of patches aims at 'decouple ISM device hard code from SMC-D stack'
Maybe now would be a good point in time to decide what ISM should mean in net/smc.
a) the s390 ISM devices
b) SMC-D devices in general
I would vote for a). (today a) and b) can be found in the code, as well as the term smcd_dev)

Then like Jan wrote above:
"0xFF00 - 0xFFFF is the range of all virtual SMC-D devices" and it should NOT be called SMC_VIRT_ISM_CHID_MAX.


Then in many places in net/smc 'ism' should be replaces by 'smcd_dev' or something similar.
Wen Gu, is that something you would offer to do as part of the preparation work for this series?