On 11 November 2014 12:10, Frank Blaschka <blasc...@linux.vnet.ibm.com> wrote:
> On Mon, Nov 10, 2014 at 04:56:21PM +0100, Alexander Graf wrote:
>> > +static uint8_t barsize(uint64_t size)
>> > +{
>> > + uint64_t mask = 1;
>> > + int i;
>> > +
>> > + if (!size) {
>> > + return 0;
>> > + }
>> > +
>> > + for (i = 0; i < 64; i++) {
>> > + if (size & mask) {
>> > + break;
>> > + }
>> > + mask = (mask << 1);
>> > + }
>> > +
>> > + return i;
>> > +}
>>
>> Isn't there an existing helper for this in the PCI layer?
>>
>
> Did not find one, this function is used to fill a s390 specific len
> in an instruction intercept (architecture specific encoding of the len).
If you do need to implement this here then you should probably
be using ctz64(). I think what you have here is equivalent to
return size ? ctz64(size) : 0;
but you should check that.
thanks
-- PMM
