On Fri, Nov 06, 2026 at 04:50:19PM +0200, Jani Nikula wrote: > 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?
Just raw readb/readw. > > > 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. Only intel_de.{c,h} need the definition so seems like it belongs there. > > 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 -- Ville Syrjälä Intel
