[Intel-gfx] [PATCH 0/3] drm/i915: introduce macros to define register contents

[Jani Nikula]

Actual serious v1 after the RFC [1].

The major change is to add local wrappers or versions of the BIT(),
GENMASK(), and FIELD_PREP() macros for i915_reg.h to ensure u32 type and
integer constant expressions.

It's a bit of a meh but does provide an opportunity for unified local
naming of the macros. After some back and forth, REG_BIT(),
REG_FIELD_MASK() and REG_FIELD() are what I settled on, but I guess I
expect some bikeshedding...

The big loss is the build-time checking of the defined field values;
FIELD_PREP() does it in a way that prohibits macro use in e.g. case
labels.

bloat-o-meter indicates slight increase, unsurprising due to the added
masking to avoid the values overflowing their fields. The changed sample
is too small to make any big conclusions though.

add/remove: 0/0 grow/shrink: 3/0 up/down: 81/0 (81)
Function                                     old     new   delta
intel_dp_init_panel_power_sequencer_registers     863     912     +49
intel_pre_enable_lvds                        618     646     +28
intel_pps_readout_hw_state                   385     389      +4
Total: Before=1106128, After=1106209, chg +0.01%


BR,
Jani.


[1] https://patchwork.freedesktop.org/series/50267/


Cc: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
Cc: Mika Kuoppala <mika.kuoppala at linux.intel.com>

Jani Nikula (3):
  drm/i915: introduce REG_BIT() and REG_FIELD_MASK() to define register
    contents
  drm/i915: deprecate _SHIFT in favor of FIELD_GET() and _MASK
  drm/i915: introduce REG_FIELD() to define register field values

 drivers/gpu/drm/i915/i915_reg.h   | 129 ++++++++++++++++++++------------------
 drivers/gpu/drm/i915/intel_dp.c   |  42 +++++--------
 drivers/gpu/drm/i915/intel_lvds.c |  40 ++++++------
 3 files changed, 104 insertions(+), 107 deletions(-)

-- 
2.11.0