drm/i915: Import Linux commit 71244653a8fb0f46bc12ae421f1d5f72af6a75da

Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Mon Jun 4 18:39:20 2012 +0200

    drm/i915: adjusted_mode->clock in the dp mode_fixup

    ... instead of changing mode->clock, which we should leave as-is.

    After the previous patch we only touch that if it's a panel, and then
    adjusted mode->clock equals adjusted_mode->clock. Outside of
    intel_dp.c we only use ajusted_mode->clock in the mode_set functions.

    Within intel_dp.c we only use it to calculate the dp dithering
    and link bw parameters, so that's the only thing we need to fix
    up.

    As a temporary ugliness (until the cleanup in the next patch) we
    pass the adjusted_mode into dp_dither for both parameters (because
    that one still looks at mode->clock).

    Note that we do overwrite adjusted_mode->clock with the selected dp
    link clock, but that only happens after we've calculated everything we
    need based on the dotclock of the adjusted output configuration.

    Outside of intel_dp.c only intel_display.c uses adjusted_mode->clock,
    and that stays the same after this patch (still equals the selected dp
    link clock). intel_display.c also needs the actual dotclock (as
    target_clock), but that has been fixed up in the previous patch.

    v2: Adjust the debug message to also use adjusted_mode->clock.

    Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
    Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
    Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
drm: Const'ify the 1st "drm_display_mode" passed to "mode_fixup" callbacks

This will be needed by the Radeon KMS driver.
drm: Fix leak of connector->edid_blob_ptr
Add an mbuf pointer parameter to (*ext_free) to give the external
free function access to the mbuf the external memory was attached
to.

Mechanically adjust all users to include the mbuf parameter.

This fixes a long standing annoyance for external free functions.
Before one had to sacrifice one of the argument pointers for this.

Sponsored by:	The FreeBSD Foundation
Remove unnecessary setup of the m->pkthdr.header pointer.

Sponsored by:	The FreeBSD Foundation
Fix a printf format warning on 32-bit mips and powerpc.

Reported by:	bde, gjb
Pointy hat to:	ken
Change local variable tso_segsz to tsosegsz to avoid mbuf.h macro conflicts.

Sponsored by:	The FreeBSD Foundation
Restructure the mbuf pkthdr to make it fit for upcoming capabilities and
features.  The changes in particular are:

o Remove rarely used "header" pointer and replace it with a 64bit protocol/
  layer specific union PH_loc for local use.  Protocols can flexibly overlay
  their own 8 to 64 bit fields to store information while the packet is
  worked on.

o Mechanically convert IP reassembly, IGMP/MLD and ATM to use pkthdr.PH_loc
  instead of pkthdr.header.

o Extend csum_flags to 64bits to allow for additional future offload
  information to be carried (e.g. iSCSI, IPsec offload, and others).

o Move the RSS hash type enumerator from abusing m_flags to its own 8bit
  rsstype field.  Adjust accessor macros.

o Add cosqos field to store Class of Service / Quality of Service information
  with the packet.  It is not yet supported in any drivers but allows us to
  get on par with Cisco/Juniper in routing applications (plus MPLS QoS) with
  a modernized ALTQ.

o Add four 8 bit fields l[2-5]hlen to store the relative header offsets
  from the start of the packet.  This is important for various offload
  capabilities and to relieve the drivers from having to parse the packet
  and protocol headers to find out location of checksums and other
  information.  Header parsing in drivers is a lot of copy-paste and
  unhandled corner cases which we want to avoid.

o Add another flexible 64bit union to map various additional persistent
  packet information, like ether_vtag, tso_segsz and csum fields.
  Depending on the csum_flags settings some fields may have different usage
  making it very flexible and adaptable to future capabilities.

o Restructure the CSUM flags to better signify their outbound (down the
  stack) and inbound (up the stack) use.  The CSUM flags used to be a bit
  chaotic and rather poorly documented leading to incorrect use in many
  places.  Bring clarity into their use through better naming.
  Compatibility mappings are provided to preserve the API.  The drivers
  can be corrected one by one and MFC'd without issue.

o The size of pkthdr stays the same at 48/56bytes (32/64bit architectures).

Sponsored by:	The FreeBSD Foundation
Add mtodo(m, o) macro taking an additional offset into the mbuf data section.

Sponsored by:	The FreeBSD Foundation
sh: Reject ++ and -- in arithmetic.

POSIX does not require ++ and -- in arithmetic. It is probably more useful
to reject them than to treat ++x and --x as x silently.

Note that the behaviour of increment and decrement can be obtained via
(x+=1), ((x+=1)-1), (x-=1) and ((x-=1)+1).

PR:		bin/176444
Compact m_hdr by packing the type and flags fields into one uint32_t.

The mbuf type is an enumerator with only a handful of types in use and
thus reduced from int to 8bits allowing for 255 types to be specified.
Only 5 types have been in use for a long time.

The flags field gets the remaining 24 bits with 12 bits for global
persistent flags and 12 bits for protocol/layer specific overlays.
Some of the global flags/functionality can be moved to the csum_flags
or ext_flags bits in the future.

MT_VENDOR[1-4] and MT_EXP[1-4] types for vendor-internal and
experimental local mapping are added.

The size of m_hdr shrinks from 24/40 to 20/32bytes (32/64bit architectures).

Sponsored by:	The FreeBSD Foundation
Remove some code that has been commented out since it was added in 2000.
Do not use "Enable Implied Seek" on enhanced floppy controllers.  This
breaks the "2step" feature of the driver, e.g. in order to read 360
KiB media on a 1200 KiB drive.

As the only potential advantage of implied (vs. explicit) seeks is to
minimize the software effort, yet our driver always contained the
logic needed for explicit seeks, simply dropping implied seeks is the
best solution without introducing risks for new bugs.  There is no
performance penalty, reading a 1440 KiB medium takes exactly the same
time with both, implied or explicit seeks.

MFC after:	1 week
Remove the kld lock macros and just use the sx(9) API. Add locking in
linker_init_kernel_modules() and linker_preload() in order to remove most
of the checks for !cold before asserting that the kld lock is held. These
routines are invoked by SYSINIT(9), so there's no harm in them taking the
kld lock.
Set things up so that linker_file_lookup_set() is always called with the
linker lock held. This makes it possible to call it from a kld event handler
with the shared lock held.

Reviewed by:	jhb
Remove unused m_free_fast().  The difference to m_free() is only
2 predictable branches nowadays.  However as a pre-condition the
caller had to ensure that the mbuf pkthdr did not have any mtags
attached to it, costing some potential branches again.

Sponsored by:	The FreeBSD Foundation
Rename the kld_unload event handler to kld_unload_try, and add a new
kld_unload event handler which gets invoked after a linker file has been
successfully unloaded. The kld_unload and kld_load event handlers are now
invoked with the shared linker lock held, while kld_unload_try is invoked
with the lock exclusively held.

Convert hwpmc(4) to use these event handlers instead of having
kern_kldload() and kern_kldunload() invoke hwpmc(4) hooks whenever files are
loaded or unloaded. This has no functional effect, but simplifes the linker
code somewhat.

Reviewed by:	jhb
After r254779 "error" must always be present in mb_ctor_pack(),
not only when MAC is defined.

Reported by:	gjb / tinderbox
Sponsored by:	The FreeBSD Foundation
Fix BUGS section after botched modify in r254772.

Reported by:	bjk
drm: Import drm_dp_helper.c from Linux 3.8-rc3

While here, update drm_dp_helper.h to better match Linux one.