sys: Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

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)

Remove legacy drm and drm2 from tree

As discussed on the MLs drm2 conflicts with the ports' version and there
is no upstream for most if not all of drm. Both have been merged in to
a single port.

Users on powerpc, 32-bit hardware, or with GPUs predating Radeon
and i915 will need to install the graphics/drm-legacy-kmod. All
other users should be able to use one of the LinuxKPI-based ports:
graphics/drm-stable-kmod, graphics/drm-next-kmod, graphics/drm-devel-kmod.

MFC: never
Approved by: core@

drm/ttm: Import Linux commit f2d476a110bc24fde008698ae9018c99e803e25c

Author: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Date: Tue Jan 15 14:57:10 2013 +0100

drm/ttm: use ttm_bo_reserve_slowpath_nolru in ttm_eu_reserve_buffers, v2

This requires re-use of the seqno, which increases fairness slightly.
Instead of spinning with a new seqno every time we keep the current one,
but still drop all other reservations we hold. Only when we succeed,
we try to get back our other reservations again.

This should increase fairness slightly as well.

Changes since v1:
- Increase val_seq before calling ttm_bo_reserve_slowpath_nolru and
retrying to take all entries to prevent a race.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Reviewed-by: Jerome Glisse <jglisse@redhat.com>

Approved by: kib@

drm/ttm: Import Linux commit 7a1863084c9d90ce4b67d645bf9b0f1612e68f62

Author: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Date: Tue Jan 15 14:56:48 2013 +0100

drm/ttm: cleanup ttm_eu_reserve_buffers handling

With the lru lock no longer required for protecting reservations we
can just do a ttm_bo_reserve_nolru on -EBUSY, and handle all errors
in a single path.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Reviewed-by: Jerome Glisse <jglisse@redhat.com>

drm/ttm: Import Linux commit 63d0a4195560362e2e00a3ad38fc331d34e1da9b

Author: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Date: Tue Jan 15 14:56:37 2013 +0100

drm/ttm: remove lru_lock around ttm_bo_reserve

There should no longer be assumptions that reserve will always succeed
with the lru lock held, so we can safely break the whole atomic
reserve/lru thing. As a bonus this fixes most lockdep annotations for
reservations.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Reviewed-by: Jerome Glisse <jglisse@redhat.com>

Import the preliminary port of the TTM.

The early commit is done to facilitate the off-tree work on the
porting of the Radeon driver.

Sponsored by: The FreeBSD Foundation
Debugged and tested by: dumbbell
MFC after: 1 month