ASID_BITS
#define ASID_MASK ((~0ULL) << ASID_BITS)
pid = task_pid_nr(thread_task(thread)) << ASID_BITS;
if (!((asid ^ atomic64_read(&asid_generation)) >> ASID_BITS)
if ((asid ^ atomic64_read(&asid_generation)) >> ASID_BITS) {
#define ASID_FIRST_VERSION (1ULL << ASID_BITS)