[Intel-gfx] [PATCH] drm/i915: abstract and document register picking macros

[Jani Nikula]

On Fri, 29 Jun 2018, Rodrigo Vivi <rodrigo.vivi at intel.com> wrote:
> On Fri, Jun 29, 2018 at 01:20:39PM +0300, Jani Nikula wrote:
>> Try to describe what the pick variants do, and which to prefer. No
>> functional changes.
>> 
>> Signed-off-by: Jani Nikula <jani.nikula at intel.com>
>
> Reviewed-by: Rodrigo Vivi <rodrigo.vivi at intel.com>

Thanks, pushed.

BR,
Jani.

>
>> 
>> ---
>> 
>> Let the naming bikeshed fest begin!
>> ---
>>  drivers/gpu/drm/i915/i915_reg.h | 28 ++++++++++++++++++++++------
>>  1 file changed, 22 insertions(+), 6 deletions(-)
>> 
>> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
>> index c30cfcd90754..7dc774682922 100644
>> --- a/drivers/gpu/drm/i915/i915_reg.h
>> +++ b/drivers/gpu/drm/i915/i915_reg.h
>> @@ -139,19 +139,35 @@ static inline bool i915_mmio_reg_valid(i915_reg_t reg)
>>  	return !i915_mmio_reg_equal(reg, INVALID_MMIO_REG);
>>  }
>>  
>> +/*
>> + * Given the first two numbers __a and __b of arbitrarily many evenly spaced
>> + * numbers, pick the 0-based __index'th value.
>> + *
>> + * Always prefer this over _PICK() if the numbers are evenly spaced.
>> + */
>> +#define _PICK_EVEN(__index, __a, __b) ((__a) + (__index) * ((__b) - (__a)))
>> +
>> +/*
>> + * Given the arbitrary numbers in varargs, pick the 0-based __index'th number.
>> + *
>> + * Always prefer _PICK_EVEN() over this if the numbers are evenly spaced.
>> + */
>>  #define _PICK(__index, ...) (((const u32 []){ __VA_ARGS__ })[__index])
>>  
>> -#define _PIPE(pipe, a, b) ((a) + (pipe) * ((b) - (a)))
>> +/*
>> + * Named helper wrappers around _PICK_EVEN() and _PICK().
>> + */
>> +#define _PIPE(pipe, a, b) _PICK_EVEN(pipe, a, b)
>>  #define _MMIO_PIPE(pipe, a, b) _MMIO(_PIPE(pipe, a, b))
>> -#define _PLANE(plane, a, b) _PIPE(plane, a, b)
>> +#define _PLANE(plane, a, b) _PICK_EVEN(plane, a, b)
>>  #define _MMIO_PLANE(plane, a, b) _MMIO_PIPE(plane, a, b)
>> -#define _TRANS(tran, a, b) ((a) + (tran) * ((b) - (a)))
>> +#define _TRANS(tran, a, b) _PICK_EVEN(tran, a, b)
>>  #define _MMIO_TRANS(tran, a, b) _MMIO(_TRANS(tran, a, b))
>> -#define _PORT(port, a, b) ((a) + (port) * ((b) - (a)))
>> +#define _PORT(port, a, b) _PICK_EVEN(port, a, b)
>>  #define _MMIO_PORT(port, a, b) _MMIO(_PORT(port, a, b))
>>  #define _MMIO_PIPE3(pipe, a, b, c) _MMIO(_PICK(pipe, a, b, c))
>>  #define _MMIO_PORT3(pipe, a, b, c) _MMIO(_PICK(pipe, a, b, c))
>> -#define _PLL(pll, a, b) ((a) + (pll) * ((b) - (a)))
>> +#define _PLL(pll, a, b) _PICK_EVEN(pll, a, b)
>>  #define _MMIO_PLL(pll, a, b) _MMIO(_PLL(pll, a, b))
>>  #define _PHY3(phy, ...) _PICK(phy, __VA_ARGS__)
>>  #define _MMIO_PHY3(phy, a, b, c) _MMIO(_PHY3(phy, a, b, c))
>> @@ -6874,7 +6890,7 @@ enum {
>>  #define _PS_ECC_STAT_2B     0x68AD0
>>  #define _PS_ECC_STAT_1C     0x691D0
>>  
>> -#define _ID(id, a, b) ((a) + (id) * ((b) - (a)))
>> +#define _ID(id, a, b) _PICK_EVEN(id, a, b)
>>  #define SKL_PS_CTRL(pipe, id) _MMIO_PIPE(pipe,        \
>>  			_ID(id, _PS_1A_CTRL, _PS_2A_CTRL),       \
>>  			_ID(id, _PS_1B_CTRL, _PS_2B_CTRL))
>> -- 
>> 2.11.0
>> 
>> _______________________________________________
>> Intel-gfx mailing list
>> Intel-gfx at lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Jani Nikula, Intel Open Source Graphics Center