On Thu, 05 Nov 2026, Ville Syrjala <[email protected]> wrote: > From: Ville Syrjälä <[email protected]> > > Different platforms will need to do different things in > their mmio accessors. The plan is to trade the overhead > of runtime platform checks into no runtime checks and > the cost of a vfunc call. This seems to provide slightly > better overall performance.
What's the plan for the 8- and 16-bit counterparts? > Signed-off-by: Ville Syrjälä <[email protected]> > --- > drivers/gpu/drm/i915/display/intel_de.c | 17 +++++++++++++++++ > drivers/gpu/drm/i915/display/intel_de.h | 9 +++++++-- > .../gpu/drm/i915/display/intel_display_core.h | 2 ++ > 3 files changed, 26 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/i915/display/intel_de.c > b/drivers/gpu/drm/i915/display/intel_de.c > index 6b3d06147e58..4f423a684ec2 100644 > --- a/drivers/gpu/drm/i915/display/intel_de.c > +++ b/drivers/gpu/drm/i915/display/intel_de.c > @@ -163,7 +163,24 @@ u16 intel_de_read16(struct intel_display *display, > intel_reg_t reg) > return intel_uncore_read16(__to_uncore(display), reg); > } > > +static u32 i9xx_mmio_read(struct intel_display *display, intel_reg_t reg) > +{ > + return intel_uncore_read(__to_uncore(display), reg); > +} > + > +static void i9xx_mmio_write(struct intel_display *display, intel_reg_t reg, > u32 val) > +{ > + intel_uncore_write(__to_uncore(display), reg, val); > +} > + > +static const struct intel_mmio_funcs i9xx_mmio_funcs = { > + .read = i9xx_mmio_read, > + .write = i9xx_mmio_write, > +}; > + > void intel_de_init(struct intel_display *display) > { > display->mmio.uncore = to_intel_uncore(display->drm); > + > + display->mmio.funcs = &i9xx_mmio_funcs; > } > diff --git a/drivers/gpu/drm/i915/display/intel_de.h > b/drivers/gpu/drm/i915/display/intel_de.h > index f1135ee5071b..63aef17e6ed3 100644 > --- a/drivers/gpu/drm/i915/display/intel_de.h > +++ b/drivers/gpu/drm/i915/display/intel_de.h > @@ -12,6 +12,11 @@ > #include "intel_uncore.h" > #include "intel_uncore_trace.h" > > +struct intel_mmio_funcs { > + u32 (*read)(struct intel_display *display, intel_reg_t reg); > + void (*write)(struct intel_display *display, intel_reg_t reg, u32 val); > +}; > + Wondering if this should be in intel_display_core.h as all the other ones are. But let's see how it pans out. Reviewed-by: Jani Nikula <[email protected]> > static inline struct intel_uncore *__to_uncore(struct intel_display *display) > { > return display->mmio.uncore; > @@ -30,7 +35,7 @@ intel_de_read(struct intel_display *display, intel_reg_t > reg) > > intel_dmc_wl_get(display, reg); > > - val = intel_uncore_read(__to_uncore(display), reg); > + val = display->mmio.funcs->read(display, reg); > > intel_dmc_wl_put(display, reg); > > @@ -60,7 +65,7 @@ intel_de_write(struct intel_display *display, intel_reg_t > reg, u32 val) > { > intel_dmc_wl_get(display, reg); > > - intel_uncore_write(__to_uncore(display), reg, val); > + display->mmio.funcs->write(display, reg, val); > > intel_dmc_wl_put(display, reg); > } > diff --git a/drivers/gpu/drm/i915/display/intel_display_core.h > b/drivers/gpu/drm/i915/display/intel_display_core.h > index 35409f9abb2f..3a48119f7890 100644 > --- a/drivers/gpu/drm/i915/display/intel_display_core.h > +++ b/drivers/gpu/drm/i915/display/intel_display_core.h > @@ -49,6 +49,7 @@ struct intel_fbdev; > struct intel_fdi_funcs; > struct intel_hotplug_irq_funcs; > struct intel_initial_plane_config; > +struct intel_mmio_funcs; > struct intel_opregion; > struct intel_overlay; > struct intel_uncore; > @@ -533,6 +534,7 @@ struct intel_display { > > struct { > struct intel_uncore *uncore; > + const struct intel_mmio_funcs *funcs; > } mmio; > > struct { -- Jani Nikula, Intel
