On 15.08.2024 12:00, oleksii.kuroc...@gmail.com wrote:
> On Wed, 2024-08-14 at 17:53 +0200, Jan Beulich wrote:
>> On 14.08.2024 17:41, oleksii.kuroc...@gmail.com wrote:
>>> On Tue, 2024-08-13 at 11:34 +0200, Jan Beulich wrote:
>>>> On 09.08.2024 18:19, Oleksii Kurochko wrote:
>>>>> +static unsigned long sbi_major_version(void)
>>>>> +{
>>>>> + return (sbi_spec_version >> SBI_SPEC_VERSION_MAJOR_SHIFT)
>>>>> &
>>>>> + SBI_SPEC_VERSION_MAJOR_MASK;
>>>>> +}
>>>>
>>>> Can you use MASK_EXTR() here, allowing to even drop the separate
>>>> SBI_SPEC_VERSION_MAJOR_SHIFT?
>>> I am not sure that:
>>> (sbi_spec_version >> SBI_SPEC_VERSION_MAJOR_SHIFT) &
>>> SBI_SPEC_VERSION_MAJOR_MASK == MASK_EXTR(sbi_spec_version,
>>> SBI_SPEC_VERSION_MAJOR_MASK)
>>
>> How come you're not sure? That's precisely what MASK_EXTR() is for.
> As the order matter here. First should be shift then applying
> SBI_SPEC_VERSION_MAJOR_MASK, as SBI_SPEC_VERSION_MAJOR_MASK is defined
> now as 7f. If SBI_SPEC_VERSION_MAJOR_MASK set to 0x7F000000 then it
> will work.
The assumption was of course that you'd adjust SBI_SPEC_VERSION_MAJOR_MASK.
That's the underlying idea after all: When the mask is shifted to its
appropriate position, the shift amount needed can be calculated from it.
Hence the lack of a need for SBI_SPEC_VERSION_MAJOR_SHIFT (and alike).
Jan
