Re: [Intel-gfx] [RFC] drm/i915: make dev_priv usage explitic in some macros

[Jani Nikula <jani.nikula@linux.intel.com>]

On Wed, 01 Feb 2023, Luca Coelho <luciano.coelho@intel.com> wrote:
> There are a few macros (e.g. DPLL()) that implicitly use dev_priv, by
> using other macros that implcitily use dev_priv.
>
> In an effort to align all definitions of struct drm_i915_private to be
> declared as i915 instead of arbitrarily using either i915 or dev_priv,
> we need to make these macros explicitly use dev_priv, so that we can
> change them later to be defined as i915.

Lucas posted a slightly related patch [1], and I think based on the
discussion we should probably add AUX and DPLL registers that are
VLV/CHV specific, and include the MMIO offset directly without dev_priv,
and non-VLV/CHV macros that will have MMIO offset 0. This would reduce
the implicit dev_priv considerably, and avoid the need to pass i915
pointer to those register macros altogether.

> diff --git a/drivers/gpu/drm/i915/display/vlv_dsi_regs.h b/drivers/gpu/drm/i915/display/vlv_dsi_regs.h
> index abbe427e462e..d00e9321064a 100644
> --- a/drivers/gpu/drm/i915/display/vlv_dsi_regs.h
> +++ b/drivers/gpu/drm/i915/display/vlv_dsi_regs.h
> @@ -100,7 +100,7 @@
>  
>  #define _MIPIA_DEVICE_READY		(_MIPI_MMIO_BASE(dev_priv) + 0xb000)
>  #define _MIPIC_DEVICE_READY		(_MIPI_MMIO_BASE(dev_priv) + 0xb800)
> -#define MIPI_DEVICE_READY(port)		_MMIO_MIPI(port, _MIPIA_DEVICE_READY, _MIPIC_DEVICE_READY)
> +#define MIPI_DEVICE_READY(dev_priv, port) _MMIO_MIPI(port, _MIPIA_DEVICE_READY, _MIPIC_DEVICE_READY)

While this kind of passes dev_priv as parameter, the dev_priv in
_MIPIA_DEVICE_READY and _MIPIC_DEVICE_READY is still implicit. I think
these could use a similar treatment as in [1], moving the
_MIPI_MMIO_BASE() part one level up.


BR,
Jani.


[1] https://patchwork.freedesktop.org/patch/msgid/20230131191542.1695398-2-lucas.demarchi@intel.com

-- 
Jani Nikula, Intel Open Source Graphics Center