On Thu, Sep 1, 2022 at 11:03 AM Wilfred Mallawa <wilfred.mall...@opensource.wdc.com> wrote: > > From: Wilfred Mallawa <wilfred.mall...@wdc.com> > > Adds a helper macro that implements the `rw1c` > behaviour. > > Ex: > uint32_t data = FIELD32_1CLEAR(val, REG, FIELD); > > if the specified `FIELD` is set (single/multi bit all fields) > then the respective field is cleared and returned to `data`. > > If ALL bits of the bitfield are not set, then no change and > val is returned.
I feel like the value is operating over the entire field. Say for example there is an interrupt pending register, with a current value of 0b0010. If a guest writes 0b1111 they expect ALL of the bits to be cleared (for a w1c register). I think the macro should handle that, instead of requiring the exact bits to be set. Alistair > > Signed-off-by: Wilfred Mallawa <wilfred.mall...@wdc.com> > --- > include/hw/registerfields.h | 28 ++++++++++++++++++++++++++++ > 1 file changed, 28 insertions(+) > > diff --git a/include/hw/registerfields.h b/include/hw/registerfields.h > index 1330ca77de..5a804f72e3 100644 > --- a/include/hw/registerfields.h > +++ b/include/hw/registerfields.h > @@ -115,6 +115,34 @@ > R_ ## reg ## _ ## field ## _LENGTH, _v.v); \ > _d; }) > > +/* Get the max value (uint) discribed by `num_bits` bits */ > +#define MAX_N_BITS(num_bits) ((1 << (num_bits)) - 1) > + > +/* > + * Clear the specified field in reg_val if > + * all field bits are set, else no changes made. Implements > + * single/multi-bit `rw1c` > + */ > +#define FIELD8_1CLEAR(reg_val, reg, field) \ > + ((FIELD_EX8(reg_val, reg, field) == \ > + MAX_N_BITS(R_ ## reg ## _ ## field ## _LENGTH)) ? \ > + FIELD_DP8(reg_val, reg, field, 0x00) : reg_val) > + > +#define FIELD16_1CLEAR(reg_val, reg, field) \ > + ((FIELD_EX16(reg_val, reg, field) == \ > + MAX_N_BITS(R_ ## reg ## _ ## field ## _LENGTH)) ? \ > + FIELD_DP16(reg_val, reg, field, 0x00) : reg_val) > + > +#define FIELD32_1CLEAR(reg_val, reg, field) \ > + ((FIELD_EX32(reg_val, reg, field) == \ > + MAX_N_BITS(R_ ## reg ## _ ## field ## _LENGTH)) ? \ > + FIELD_DP32(reg_val, reg, field, 0x00) : reg_val) > + > +#define FIELD64_1CLEAR(reg_val, reg, field) \ > + ((FIELD_EX64(reg_val, reg, field) == \ > + MAX_N_BITS(R_ ## reg ## _ ## field ## _LENGTH)) ? \ > + FIELD_DP64(reg_val, reg, field, 0x00) : reg_val) > + > #define FIELD_SDP8(storage, reg, field, val) ({ \ > struct { \ > signed int v:R_ ## reg ## _ ## field ## _LENGTH; \ > -- > 2.37.2 > >