On 02/21/2018 05:55 PM, Ram Pai wrote: > +static inline u32 pkey_to_shift(int pkey) > +{ > + return pkey * PKEY_BITS_PER_PKEY; > +} pkey_bit_position(), perhaps? > +static inline pkey_reg_t reset_bits(int pkey, pkey_reg_t bits) > +{ > + u32 shift = pkey_to_shift(pkey); > + > + return ~(bits << shift); > +} I'd prefer clear_pkey_flags() or maybe clear_pkey_bits(). "reset" can mean "reset to 0" or "reset to 1". Also, why the u32 here? Isn't an int more appropriate? > +static inline pkey_reg_t left_shift_bits(int pkey, pkey_reg_t bits) > +{ > + u32 shift = pkey_to_shift(pkey); > + > + return (bits << shift); > +} > + > +static inline pkey_reg_t right_shift_bits(int pkey, pkey_reg_t bits) > +{ > + u32 shift = pkey_to_shift(pkey); > + > + return (bits >> shift); > +} Some comments on these would be handy. Basically that this takes a per-key flags value and puts it at the right position so it can be shoved in the register.