On 11/19/20 9:26 AM, Thomas Huth wrote:
> On 17/11/2020 16.42, Janosch Frank wrote:
>> Query/feature bits are commonly tested via MSB bit numbers on
>> s390. Let's add test bit functions, so we don't need to copy code to
>> test query bits.
>>
>> Signed-off-by: Janosch Frank <frankja@xxxxxxxxxxxxx>
>> ---
>> lib/s390x/asm/bitops.h | 16 ++++++++++++++++
>> lib/s390x/asm/facility.h | 3 ++-
>> 2 files changed, 18 insertions(+), 1 deletion(-)
>>
>> diff --git a/lib/s390x/asm/bitops.h b/lib/s390x/asm/bitops.h
>> index e7cdda9..a272dd7 100644
>> --- a/lib/s390x/asm/bitops.h
>> +++ b/lib/s390x/asm/bitops.h
>> @@ -7,4 +7,20 @@
>>
>> #define BITS_PER_LONG 64
>>
>> +static inline bool test_bit(unsigned long nr,
>> + const volatile unsigned long *ptr)
>> +{
>> + const volatile unsigned char *addr;
>> +
>> + addr = ((const volatile unsigned char *)ptr);
>> + addr += (nr ^ (BITS_PER_LONG - 8)) >> 3;
>> + return (*addr >> (nr & 7)) & 1;
>> +}
>> +
>> +static inline bool test_bit_inv(unsigned long nr,
>> + const volatile unsigned long *ptr)
>> +{
>> + return test_bit(nr ^ (BITS_PER_LONG - 1), ptr);
>> +}
>
> I think you should mention in the patch description that these functions
> match the implementations in the kernel (and thus are good for kernel
> developers who are used to these).
There are only so many ways one can write 4 lines of code :-)
>
> Thus I think you should also now add a license statement to this file
> ("SPDX-License-Identifier: GPL-2.0" or so).
Definitely, thanks for reminding me
>
> With these modifications:
> Reviewed-by: Thomas Huth <thuth@xxxxxxxxxx>
>
Thanks
