ARCH_P4_CNTRVAL_BITS
.cntval_bits = ARCH_P4_CNTRVAL_BITS,
.max_period = (1ULL << (ARCH_P4_CNTRVAL_BITS - 1)) - 1,
#define ARCH_P4_CNTRVAL_MASK ((1ULL << ARCH_P4_CNTRVAL_BITS) - 1)
#define ARCH_P4_UNFLAGGED_BIT ((1ULL) << (ARCH_P4_CNTRVAL_BITS - 1))