Re: [PATCH v14 1/9] xen: introduce generic non-atomic test_*bit()

[Jan Beulich <jbeulich@xxxxxxxx>]

On 02.07.2024 15:11, Michal Orzel wrote:
> Hi Oleksii,
> 
> On 02/07/2024 13:01, Oleksii Kurochko wrote:
>>
>>
>> The following generic functions were introduced:
>> * test_bit
>> * generic__test_and_set_bit
>> * generic__test_and_clear_bit
>> * generic__test_and_change_bit
>>
>> These functions and macros can be useful for architectures
>> that don't have corresponding arch-specific instructions.
>>
>> Also, the patch introduces the following generics which are
>> used by the functions mentioned above:
>> * BITOP_BITS_PER_WORD
>> * BITOP_MASK
>> * BITOP_WORD
>> * BITOP_TYPE
>>
>> The following approach was chosen for generic*() and arch*() bit
>> operation functions:
>> If the bit operation function that is going to be generic starts
>> with the prefix "__", then the corresponding generic/arch function
>> will also contain the "__" prefix. For example:
>>  * test_bit() will be defined using arch_test_bit() and
>>    generic_test_bit().
>>  * __test_and_set_bit() will be defined using
>>    arch__test_and_set_bit() and generic__test_and_set_bit().
>>
>> Signed-off-by: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>
>> Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
> Reviewed-by: Michal Orzel <michal.orzel@xxxxxxx>
> 
> with one question...
> 
> [...]
> 
>> diff --git a/xen/include/xen/bitops.h b/xen/include/xen/bitops.h
>> index 6a5e28730a..cc09d273c9 100644
>> --- a/xen/include/xen/bitops.h
>> +++ b/xen/include/xen/bitops.h
>> @@ -4,6 +4,19 @@
>>  #include <xen/compiler.h>
>>  #include <xen/types.h>
>>
>> +#define BITOP_BITS_PER_WORD 32
>> +typedef uint32_t bitop_uint_t;
>> +
>> +#define BITOP_MASK(nr)  ((bitop_uint_t)1 << ((nr) % BITOP_BITS_PER_WORD))
>> +
>> +#define BITOP_WORD(nr)  ((nr) / BITOP_BITS_PER_WORD)
>> +
>> +#define BITS_PER_BYTE 8
> Shouldn't you remove the same macros from riscv and x86 config.h ?

Oh, good that you spotted that: This wasn't supposed to be here anymore.
Iirc we settled on this specifically wanting setting by each arch.

Jan