Revert drm2 removal.

Revert r338177, r338176, r338175, r338174, r338172

After long consultations with re@, core members and mmacy, revert
these changes. Followup changes will be made to mark them a

Revert drm2 removal.

Revert r338177, r338176, r338175, r338174, r338172

After long consultations with re@, core members and mmacy, revert
these changes. Followup changes will be made to mark them as
deprecated and prent a message about where to find the up-to-date
driver. Followup commits will be made to make this clear in the
installer. Followup commits to reduce POLA in ways we're still
exploring.

It's anticipated that after the freeze, this will be removed in
13-current (with the residual of the drm2 code copied to
sys/arm/dev/drm2 for the TEGRA port's use w/o the intel or
radeon drivers).

Due to the impending freeze, there was no formal core vote for
this. I've been talking to different core members all day, as well as
Matt Macey and Glen Barber. Nobody is completely happy, all are
grudgingly going along with this. Work is in progress to mitigate
the negative effects as much as possible.

Requested by: re@ (gjb, rgrimes)

show more ...

sys/modules: normalize .CURDIR-relative paths to SRCTOP

This simplifies make output/logic

Tested with: `cd sys/modules; make ALL_MODULES=` on amd64
MFC after: 1 month
Sponsored by: Dell EMC Isilon

Re-support CWARNFLAGS, lost when bsd.sys.mk was removed. Also, support
CWARNFALGS.$file centrally so we don't have to have it in all the
places. Remove a few warning flags that are no longer needed.

Re-support CWARNFLAGS, lost when bsd.sys.mk was removed. Also, support
CWARNFALGS.$file centrally so we don't have to have it in all the
places. Remove a few warning flags that are no longer needed.
Also, always use -Wno-unknown-pragma to (hopefully temporarily) work
around #pragma ident in debug.h in the opensolaris code. Remove some
stale warning suppression that's no longer necessary.

show more ...

Extend dim's hack from r228978: not only clang but gcc on non-x86 platforms
warns about unused variables in this code, so always add -Wno-unused to
the warning flags. Why gcc on x86 *doesn't* warn ab

Extend dim's hack from r228978: not only clang but gcc on non-x86 platforms
warns about unused variables in this code, so always add -Wno-unused to
the warning flags. Why gcc on x86 *doesn't* warn about this, I will never
know. The code itself should probably be fixed at some point.

show more ...

Don't try to build Linux compatibility stuff on platforms without
COMPAT_LINUX.

For several files in sys/dev/drm, disable -Wunused-value when building
with clang. There are several macros in these files that return values,
and in some cases nothing is done with them, but it is

For several files in sys/dev/drm, disable -Wunused-value when building
with clang. There are several macros in these files that return values,
and in some cases nothing is done with them, but it is completely
harmless. For some other files, also disable -Wconstant-conversion,
since that triggers a false positive with the DMA_BIT_MASK() macro.

MFC after: 1 week

show more ...

Welcome drm support for VIA unichrome chips.

MFC after: 2 weeks