pmc_bitmask
pmc->counter = (pmc->counter + 1) & pmc_bitmask(pmc);
u64 sample_period = (-counter_value) & pmc_bitmask(pmc);
sample_period = pmc_bitmask(pmc) + 1;
prev_counter = counter & pmc_bitmask(pmc);
pmc->counter = counter & pmc_bitmask(pmc);
pmc->counter = val & pmc_bitmask(pmc);
pmc->counter &= pmc_bitmask(pmc);
return pmc->counter & pmc_bitmask(pmc);
return counter & pmc_bitmask(pmc);