drm/i915/display: define and use intel_reg_{offset, equal, valid}() helpers

Add display specific helpers for getting the register offset, checking
for equality and validity. Add them as static inlin

drm/i915/display: define and use intel_reg_{offset, equal, valid}() helpers

Add display specific helpers for getting the register offset, checking
for equality and validity. Add them as static inlines for increased type
safety.

Reviewed-by: Michał Grzelak <michal.grzelak@intel.com>
Acked-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/7fe12d4e5465778209ccf29359767a197b031dd9.1777972548.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

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drm/i915/display: add typedef for intel_reg_t and use it

Add a typedef alias intel_reg_t for i915_reg_t, and use it exclusively
in display code. The goal is to eventually define a distinct type for

drm/i915/display: add typedef for intel_reg_t and use it

Add a typedef alias intel_reg_t for i915_reg_t, and use it exclusively
in display code. The goal is to eventually define a distinct type for
display, but for now just use an alias.

In a handful of places include intel_display_reg_defs.h instead of
i915_reg_defs.h to get the definition, and isolate the i915_reg_defs.h
include there.

Reviewed-by: Michał Grzelak <michal.grzelak@intel.com>
Acked-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/f5bb0122143c39ce7f9ce8a1605a7637e569f7f8.1777972548.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

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drm/i915/mchbar: include intel_mchbar_regs.h from intel_mchbar.h

As an exception to the rule of not including unnecessary headers from
headers, include intel_mchbar_regs.h from intel_mchbar.h. In or

drm/i915/mchbar: include intel_mchbar_regs.h from intel_mchbar.h

As an exception to the rule of not including unnecessary headers from
headers, include intel_mchbar_regs.h from intel_mchbar.h. In order to
use the interfaces in intel_mchbar.h you will always have to include the
registers anyway, so the includes are in pairs everywhere. There is zero
asymmetry. Simplify.

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/e44dc2daf3fc39d02c3f598c323caa3c08a54304.1775590536.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

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drm/i915/mchbar: Use intel_de_read*() for MCHBAR register accesses

Replace the naked intel_uncore_read*() with intel_de_read*()
in the MCHBAR code.

v2: Rebase due to intel_uncore_read64_2x32()

Rev

drm/i915/mchbar: Use intel_de_read*() for MCHBAR register accesses

Replace the naked intel_uncore_read*() with intel_de_read*()
in the MCHBAR code.

v2: Rebase due to intel_uncore_read64_2x32()

Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20260331154259.24600-12-ville.syrjala@linux.intel.com

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drm/i915/mchbar: WARN when accessing non-MCHBAR registers via intel_mchbar_read*()

The intel_mchbar_read*() functions should only be used for
accessing MCHBAR registers. Warn if someone tries to use

drm/i915/mchbar: WARN when accessing non-MCHBAR registers via intel_mchbar_read*()

The intel_mchbar_read*() functions should only be used for
accessing MCHBAR registers. Warn if someone tries to use
them for other registers.

I suppose we could even have a dedicated type for MCHBAR
registers. But that is true for many other special register
types as well, and so far we haven't bothered adding any
special types apart from i915_mcr_reg_t.

v2: Print the register offset (Jani)
Mention i915_mcr_reg_t (Jani)

Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20260331154259.24600-5-ville.syrjala@linux.intel.com

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drm/i915/mchbar: Provide intel_mchbar_read*() abstraction

MCHBAR registers are a bit special in that:
- we access them through the mirror
- the mirror is read only on HSW+
- the mirror requires the

drm/i915/mchbar: Provide intel_mchbar_read*() abstraction

MCHBAR registers are a bit special in that:
- we access them through the mirror
- the mirror is read only on HSW+
- the mirror requires the actual MCHBAR to be enabled in device 0:0.0
- the mirror is gone on MTL+

So I'd prefer to treat MCHBAR registers as a bit special in
the code as well, and do all accesses to them via dedicated
functions. Prodive such functions in the form of
intel_mchbar_read*().

v2: Put the function arguments on one line
No intel_uncore_read64() on xe, use intel_uncore_read64_2x32()
Name the new function intel_mchbar_read64_2x32() as well

Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20260331154259.24600-3-ville.syrjala@linux.intel.com

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