The atomic users and helpers assume that there is always a obj->state
structure around. Which means drivers need to somehow create that at
driver load time. Also it should obviously reset hardware state, so
needs to be reset upon resume.

Finally the destroy/duplicate_state functions are an awful lot of
boilerplate if the driver doesn't need anything beyond the default
state objects.

So add helper functions for all of this.

v2: Somehow the plane/connector versions got lost in the first
version.

v3: Add kerneldoc.

v4: Make duplicate_state functions a bit more robust, which is useful
for debugging state tracking issues when transitioning to atomic.

v5: Clear temporary variables in the crtc state when duplicating it,
like ->mode_changed or ->planes_changed. If we don't do this stale
values for these might pollute the next atomic modeset.

v6: Also clear crtc_state->event in case the driver didn't (yet) clear
this out.

v7: Split out wrong squashed commit. Also improve the kerneldoc to
mention that obj->state can be NULL and when.  Both suggested by
Daniel Thompson.

Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Sean Paul <seanpaul@chromium.org>
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Currently there is no way to implement async flips using atomic, that
essentially requires us to be able to cancel pending requests
mid-flight.

To be able to do that (and I guess we want this since vblank synced
updates which opportunistically cancel still pending updates seem to be
wanted) we'd need to add a mandatory cancellation mode. Depending upon
the exact semantics we decide upon that could mean that userspace will
not get completion events, or will get them all stacked up.

So reject async updates for now. Also async updates usually means not
vblank synced at all, and I guess for drivers which want to support
this they should simply add a special pageflip handler (since usually
you need a special flip cmd to achieve this). That kind of async flip
is pretty much exclusively just used for games and benchmarks where
dropping just one frame means you'll get a headshot or something bad
like that ... And so slight amounts of tearing is acceptable.

v2: Fixup kerneldoc, reported by Paulo.

v3: Use the set_crtc_for_plane function to assign the crtc, since
otherwise the book-keeping is off.

v4: Update crtc->primary->fb since ->page_flip is the only driver
callback where the core won't do this itself. We might want to fix
this inconsistency eventually.

v5: Use set_crtc_for_connector as suggested by Sean.

v6: Daniel Thompson noticed that my error handling is inconsistent
and that in a few cases I didn't handle fatal errors (i.e. not
-EDEADLK). Fix this by consolidate the ww mutex backoff handling
into one check in the fail: block and flatten the error control
flow everywhere else.

v7: Fix spelling mistake in the commit message (Sean).

Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Paulo Zanoni <przanoni@gmail.com>
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

No helper function to do it all yet provided since no driver has
support for driver core fences yet. Which we'd need to make the
implementation really generic.

v2: Clarify async howto a bit per the discussion With Rob Clark.

Cc: Rob Clark <robdclark@gmail.com>
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This patch is for enabling async commits. It replaces an earlier
approach which added an async boolean paramter to the ->prepare_fb
callbacks. The idea is that prepare_fb picks up the right fence to
synchronize against, which is then used by the synchronous commit
helper. For async commits drivers can either register a callback to
the fence or simply do the synchronous wait in their async work queue.

v2: Remove unused variable.

v3: Only wait for fences after the point of no return in the part
of the commit function which can be run asynchronously. This is after
the atomic state has been swapped in, hence now check
plane->state->fence.

Also add a WARN_ON to make sure we don't try to wait on a fence when
there's no fb, just as a sanity check.
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

Well, except page_flip since that requires async commit, which isn't
there yet.

For the functions which changes planes there's a bit of trickery
involved to keep the fb refcounting working. But otherwise fairly
straight-forward atomic updates.

The property setting functions are still a bit incomplete. Once we
have generic properties (e.g. rotation, but also all the properties
needed by the atomic ioctl) we need to filter those out and parse them
in the helper. Preferrably with the same function as used by the real
atomic ioctl implementation.

v2: Fixup kerneldoc, reported by Paulo.

v3: Add missing EXPORT_SYMBOL.

v4: We need to look at the crtc of the modeset, not some random
leftover one from a previous loop when udpating the connector->crtc
routing. Also push some local variables into inner loops to avoid
these kinds of bugs.

v5: Adjust semantics - drivers now own the atomic state upon
successfully synchronous commit.

v6: Use the set_crtc_for_plane function to assign the crtc, since
otherwise the book-keeping is off.

v7:
- Improve comments.
- Filter out the crtc of the ->set_config call when recomputing
  crtc_state->enabled: We should compute the same state, but not doing
  so will give us a good chance to catch bugs and inconsistencies -
  the atomic helper's atomic_check function re-validates this again.
- Fix the set_config implementation logic when disabling the crtc: We
  still need to update the output routing to disable all the
  connectors properly in the state. Caught by the atomic_check
  functions, so at least that part worked ;-) Also add some WARN_ONs
  to ensure ->set_config preconditions all apply.

v8: Fixup an embarrassing h/vdisplay mixup.

v9: Shuffled bad squash to the right patch, spotted by Daniel

v10: Use set_crtc_for_connector as suggested by Sean.

v11: Daniel Thompson noticed that my error handling is inconsistent
and that in a few cases I didn't handle fatal errors (i.e. not
-EDEADLK). Fix this by consolidate the ww mutex backoff handling
into one check in the fail: block and flatten the error control
flow everywhere else.

v12: Review and discussion with Sean:
- One spelling fix.
- Correctly skip the crtc from the set_config set when recomputing
  ->enable state. That should allow us to catch any bugs in higher
  levels in computing that state (which is supplied to the
  ->set_config implementation). I've screwed this up and Sean spotted
  that the current code is pointless.

Cc: Sean Paul <seanpaul@chromium.org>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Paulo Zanoni <przanoni@gmail.com>
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

So this is finally the integration of the crtc and plane helper
interfaces into the atomic helper functions.

In the check function we now have a few steps:

- First we update the output routing and figure out which crtcs need a
  full mode set. Suitable encoders are selected using ->best_encoder,
  with the same semantics as the crtc helpers of implicitly disabling
  all connectors currently using the encoder.

- Then we pull all other connectors into the state update which feed
  from a crtc which changes. This must be done do catch mode changes
  and similar updates - atomic updates are differences on top of the
  current state.

- Then we call all the various ->mode_fixup to compute the adjusted
  mode. Note that here we have a slight semantic difference compared
  to the crtc helpers: We have not yet updated the encoder->crtc link
  when calling the encoder's ->mode_fixup function. But that's a
  requirement when converting to atomic since we want to prepare the
  entire state completely contained with the over drm_atomic_state
  structure. So this must be carefully checked when converting drivers
  over to atomic helpers.

- Finally we do call the atomic_check functions on planes and crtcs.

The commit function is also quite a beast:

- The only step that can fail is done first, namely pinning the
  framebuffers. After that we cross the point of no return, an async
  commit would push all that into the worker thread.

- The disabling of encoders and connectors is a bit tricky, since
  depending upon the final state we need to select different crtc
  helper functions.

- Software tracking is a bit clarified compared to the crtc helpers:
  We commit the software state before starting to touch the hardware,
  like crtc helpers. But since we just swap them we still have the old
  state (i.e. the current hw state) around, which is really handy to
  write simple disable functions. So no more
  drm_crtc_helper_disable_all_unused_functions kind of fun because
  we're leaving unused crtcs/encoders behind. Everything gets shut
  down in-order now, which is one of the key differences of the i915
  helpers compared to crtc helpers and a really nice additional
  guarantee.

- Like with the plane helpers the atomic commit function waits for one
  vblank to pass before calling the framebuffer cleanup function.

Compared to Rob's helper approach there's a bunch of upsides:

- All the interfaces which can fail are called in the ->check hook
  (i.e. ->best_match and the various ->mode_fixup hooks). This means
  that drivers can just reuse those functions and don't need to move
  everything into ->atomic_check callbacks. If drivers have no need
  for additional constraint checking beyong their existing crtc
  helper callbacks they don't need to do anything.

- The actual commit operation is properly stage: First we prepare
  framebuffers, which can potentially still fail (due to memory
  exhausting). This is important for the async case, where this must
  be done synchronously to correctly return errors.

- The output configuration changes (done with crtc helper functions)
  and the plane update (using atomic plane helpers) are correctly
  interleaved: First we shut down any crtcs that need changing, then
  we update planes and finally we enable everything again. Hardware
  without GO bits must be more careful with ordering, which this
  sequence enables.

- Also for hardware with shared output resources (like display PLLs)
  we first must shut down the old configuration before we can enable
  the new one. Otherwise we can hit an impossible intermediate state
  where there's not enough PLLs (which is the point behind atomic
  updates).

v2:
- Ensure that users of ->check update crtc_state->enable correctly.
- Update the legacy state in crtc/plane structures. Eventually we want
  to remove that, but for now the drm core still expects this (especially
  the plane->fb pointer).

v3: A few changes for better async handling:

- Reorder the software side state commit so that it happens all before
  we touch the hardware. This way async support becomes very easy
  since we can punt all the actual hw touching to a worker thread. And
  as long as we synchronize with that thread (flushing or cancelling,
  depending upon what the driver can handle) before we commit the next
  software state there's no need for any locking in the worker thread
  at all. Which greatly simplifies things.

  And as long as we synchronize with all relevant threads we can have
  a lot of them (e.g. per-crtc for per-crtc updates) running in
  parallel.

- Expose pre/post plane commit steps separately. We need to expose the
  actual hw commit step anyway for drivers to be able to implement
  asynchronous commit workers. But if we expose pre/post and plane
  commit steps individually we allow drivers to selectively use atomic
  helpers.

- I've forgotten to call encoder/bridge ->mode_set functions, fix
  this.

v4: Add debug output and fix a mixup between current and new state
that resulted in crtcs not getting updated correctly. And in an
Oops ...

v5:
- Be kind to driver writers in the vblank wait functions.. if thing
  aren't working yet, and vblank irq will never come, then let's not
  block forever.. especially under console-lock.
- Correctly clear connector_state->best_encoder when disabling.
  Spotted while trying to understand a report from Rob Clark.
- Only steal encoder if it actually changed, otherwise hilarity ensues
  if we steal from the current connector and so set the ->crtc pointer
  unexpectedly to NULL. Reported by Rob Clark.
- Bail out in disable_outputs if an output currently doesn't have a
  best_encoder - this means it's already disabled.

v6: Fixupe kerneldoc as reported by Paulo. And also fix up kerneldoc
in drm_crtc.h.

v7: Take ownership of the atomic state and clean it up with
drm_atomic_state_free().

v8 Various improvements all over:
- Polish code comments and kerneldoc.
- Improve debug output to make sure all failure cases are logged.
- Treat enabled crtc with no connectors as invalid input from userspace.
- Don't ignore the return value from mode_fixup().

v9:
- Improve debug output for crtc_state->mode_changed.

v10:
- Fixup the vblank waiting code to properly balance the vblank_get/put
  calls.
- Better comments when checking/computing crtc->mode_changed

v11: Fixup the encoder stealing logic: We can't look at encoder->crtc
since that's not in the atomic state structures and might be updated
asynchronously in and async commit. Instead we need to inspect all the
connector states and check whether the encoder is currently in used
and if so, on which crtc.

v12: Review from Sean:
- A few spelling fixes.
- Flatten control flow indent by converting if blocks to early
  continue/return in 2 places.
- Capture connectors_for_crtc return value in int num_connectors
  instead of bool has_connectors and do an explicit int->bool
  conversion with !!. I think the helper is more useful for drivers if
  it returns the number of connectors (e.g. to detect cloning
  configurations), so decided to keep that return value.

Cc: Sean Paul <seanpaul@chromium.org>
Cc: Paulo Zanoni <przanoni@gmail.com>
Cc: Rob Clark <robdclark@gmail.com>
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

These two functions allow drivers to reuse their atomic plane helpers
functions for the primary plane to implement the interfaces required
by the crtc helpers for the legacy ->set_config callback.

This is purely transitional and won't be used once the driver is fully
converted. But it allows partial conversions to the atomic plane
helpers which are functional.

v2:
- Use ->atomic_duplicate_state if available.
- Don't forget to run crtc_funcs->atomic_check.

v3: Shift source coordinates correctly for 16.16 fixed point.

v4: Don't forget to call ->atomic_destroy_state if available.

v5: Fixup kerneldoc.

v6: Reuse the plane_commit function from the transitional plane
helpers to avoid too much duplication.

v7:
- Remove some stale comment.
- Correctly handle the lack of plane->state object, necessary for
  transitional use.

v8: Fixup an embarrassing h/vdisplay mixup.
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Converting a driver to the atomic interface can be a daunting
undertaking. One of the prerequisites is to have full universal planes
support.

To make that transition a bit easier this patch provides plane helpers
which use the new atomic helper callbacks just only for the plane
changes. This way the plane update functionality can be tested without
being forced to convert everything at once.

Of course a real atomic update capable driver will implement the
all plane properties through the atomic interface, so these helpers
are mostly transitional. But they can be used to enable proper
universal plane support, especially once the crtc helpers have also
been adapted.

v2: Use ->atomic_duplicate_state if available.

v3: Don't forget to call ->atomic_destroy_state if available.

v4: Fixup kerneldoc, reported by Paulo.

v5: Extract a common plane_commit helper and fix some bugs in the
plane_state setup of the plane_disable implementation.

v6: Fix issues with the cleanup of the old fb. Since transitional
helpers can be mixed we need to assume that the old fb has been set up
by a legacy path (e.g. set_config or page_flip when the primary plane
is converted to use these functions already). Hence pass an additional
old_fb parameter to plane_commit to do that cleanup work correctly.

v7:
- Fix spurious WARNING (crtc helpers really love to disable stuff
  harder) and fix array index bonghits.
- Correctly handle the lack of plane->state object, necessary for
  transitional use.
- Don't indicate failure if drm_vblank_get doesn't work - that's
  expected when the pipe is in dpms off mode.

v8: Review from Sean:
- s/fail/out/ to make the meaning of a label more clear.
- spelling fix in the commit message.

Cc: Paulo Zanoni <przanoni@gmail.com>
Cc: Sean Paul <seanpaul@chromium.org>
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This is the first cut of atomic helper code. As-is it's only useful to
implement a pure atomic interface for plane updates.

Later patches will integrate this with the crtc helpers so that full
atomic updates are possible. We also need a pile of helpers to aid
drivers in transitioning from the legacy world to the shiny new atomic
age. Finally we need helpers to implement legacy ioctls on top of the
atomic interface.

The design of the overall helpers<->driver interaction is fairly
simple, but has an unfortunate large interface:

- We have ->atomic_check callbacks for crtcs and planes. The idea is
  that connectors don't need any checking, and if they do they can
  adjust the relevant crtc driver-private state. So no connector hooks
  should be needed. Also the crtc helpers integration will do the
  ->best_encoder checks, so no need for that.

- Framebuffer pinning needs to be done before we can commit to the hw
  state. This is especially important for async updates where we must
  pin all buffers before returning to userspace, so that really only
  hw failures can happen in the asynchronous worker.

  Hence we add ->prepare_fb and ->cleanup_fb hooks for this resources
  management.

- The actual atomic plane commit can't fail (except hw woes), so has
  void return type. It has three stages:
  1. Prepare all affected crtcs with crtc->atomic_begin. Drivers can
     use this to unset the GO bit or similar latches to prevent plane
     updates.
  2. Update plane state by looping over all changed planes and calling
     plane->atomic_update. Presuming the hardware is sane and has GO
     bits drivers can simply bash the state into the hardware in this
     function. Other drivers might use this to precompute hw state for
     the final step.
  3. Finally latch the update for the next vblank with
     crtc->atomic_flush. Note that this function doesn't need to wait
     for the vblank to happen even for the synchronous case.

v2: Clear drm_<obj>_state->state to NULL when swapping in state.

v3: Add TODO that we don't short-circuit plane updates for now. Likely
no one will care.

v4: Squash in a bit of polish that somehow landed in the wrong (later)
patche.

v5: Integrate atomic functions into the drm docbook and fixup the
kerneldoc.

v6: Fixup fixup patch squashing fumble.

v7: Don't touch the legacy plane state plane->fb and plane->crtc. This
is only used by the legacy ioctl code in the drm core, and that code
already takes care of updating the pointers in all relevant cases.
This is in stark contrast to connector->encoder->crtc links on the
modeset side, which we still need to set since the core doesn't touch
them.

Also some more kerneldoc polish.

v8: Drop outdated comment.

v9: Handle the state->state pointer correctly: Only clearing the
->state pointer when assigning the state to the kms object isn't good
enough. We also need to re-link the swapped out state into the
drm_atomic_state structure.

v10: Shuffle the misplaced docbook template hunk around that Sean spotted.

Cc: Sean Paul <seanpaul@chromium.org>
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Some differences compared to Rob's patches again:
- Dropped the committed and checked booleans. Checking will be
  internally enforced by always calling ->atomic_check before
  ->atomic_commit. And async handling needs to be solved differently
  because the current scheme completely side-steps ww mutex deadlock
  avoidance (and so either reinvents a new deadlock avoidance wheel or
  like the current code just deadlocks).

- State for connectors needed to be added, since now they have a
  full-blown drm_connector_state (so that drivers have something to
  attach their own stuff to).

- Refcounting is gone. I plane to solve async updates differently,
  since the lock-passing scheme doesn't cut it (since it abuses ww
  mutexes). Essentially what we need for async is a simple ownership
  transfer from the caller to the driver. That doesn't need full-blown
  refcounting.

- The acquire ctx is a pointer. Real atomic callers should have that
  on their stack, legacy entry points need to put the right one
  (obtained by drm_modeset_legacy_acuire_ctx) in there.

- I've dropped all hooks except check/commit. All the begin/end
  handling is done by core functions and is the same.

- commit/check are just thin wrappers that ensure that ->check is
  always called.

- To help out with locking in the legacy implementations I've added a
  helper to just grab all locks in the backoff case.

v2: Add notices that check/commit can fail with EDEADLK.

v3:
- More consistent naming for state_alloc.
- Add state_clear which is needed for backoff and retry.

v4: Planes/connectors can switch between crtcs, and we need to be
careful that we grab the state (and locks) for both the old and new
crtc. Improve the interface functions to ensure this.

v5: Add functions to grab affected connectors for a crtc and to recompute
the crtc->enable state. This is useful for both helper and atomic ioctl
code when e.g. removing a connector.

v6: Squash in fixup from Fengguang to use ERR_CAST.

v7: Add debug output.

v8: Make checkpatch happy about kcalloc argument ordering.

v9: Improve kerneldoc in drm_crtc.h

v10:
- Fix another kcalloc argument misorder I've missed.
- More polish for kerneldoc.

v11: Clarify the ownership rules for the state object. The new rule is
that a successful drm_atomic_commit (whether synchronous or asnyc)
always inherits the state and is responsible for the clean-up. That
way async and sync ->commit functions are more similar.

v12: A few bugfixes:
- Assign state->state pointers correctly when grabbing state objects -
  we need to link them up with the global state.
- Handle a NULL crtc in set_crtc_for_plane to simplify code flow a bit
  for the callers of this function.

v13: Review from Sean:
- kerneldoc spelling fixes
- Don't overallocate states->planes.
- Handle NULL crtc in set_crtc_for_connector.

v14: Sprinkle __must_check over all functions which do wait/wound
locking to make sure callers don't forget this. Since I have ;-)

v15: Be more explicit in the kerneldoc when functions can return
-EDEADLK what to do. And that every other -errno is fatal.

v16: Indent with tabs instead of space, spotted by Ander.

v17: Review from Thierry, small kerneldoc and other naming polish.

Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Ander Conselvan de Oliveira <conselvan2@gmail.com>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Heavily based upon Rob Clark's atomic series.
- Dropped the connector state from the crtc state, instead opting for a
  full-blown connector state. The only thing it has is the desired
  crtc, but drivers which have connector properties have now a
  data-structure to subclass.

- Rename create_state to duplicate_state. Especially for legacy ioctls
  we want updates on top of existing state, so we need a way to get at
  the current state. We need to be careful to clear the backpointers
  to the global state correctly though.

- Drop property values. Drivers with properties simply need to
  subclass the datastructures and track the decoded values in there. I
  also think that common properties (like rotation) should be decoded
  and stored in the core structures.

- Create a new set of ->atomic_set_prop functions, for smoother
  transitions from legacy to atomic operations.

- Pass the ->atomic_set_prop ioctl the right structure to avoid
  chasing pointers in drivers.

- Drop temporary boolean state for now until we resurrect them with
  the helper functions.

- Drop invert_dimensions. For now we don't need any checking since
  that's done by the higher-level legacy ioctls. But even then we
  should also add rotation/flip tracking to the core drm_crtc_state,
  not just whether the dimensions are inverted.

- Track crtc state with an enable/disable. That's equivalent to
  mode_valid, but a bit clearer that it means the entire crtc.

The global interface will follow in subsequent patches.

v2: We need to allow drivers to somehow set up the initial state and
clear it on resume. So add a plane->reset callback for that. Helpers
will be provided with default behaviour for all these.

v3: Split out the plane->reset into a separate patch.

v4: Improve kerneldoc in drm_crtc.h

v5: Remove unused inline functions for handling state objects, those
callbacks are now mandatory for full atomic support.

v6: Fix commit message nit Sean noticed.
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

I've forgotten to do this in:

commit cb597bb3
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Sun Jul 27 19:09:33 2014 +0200

    drm: trylock modest locking for fbdev panics

Oops, fix this asap.

In my defense kerneldoc is really awful and there's no way it can pick
up structured comments per struct member. Which means we need both
since people won't scroll up even a few lines.
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Reviewed-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

I've tried to cc all the people who have recently added new stuff
but forgotten to update documentation.

I've also decided not to bother documenting the massive property list
in struct drm_mode_config. If that beast keeps on growing we might want
to extract it into a separate structure which we won't document.

Cc: Thomas Wood <thomas.wood@intel.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

While writing atomic docs I've noticed that I don't get any errors
for my screw-ups in drm_crtc.h. Fix this immediately.

This just does the bare minimum to get starts, lots of stuff isn't
properly documented yet unfortunately.

v2: Fix adjacent spelling error Sean noticed.
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Cc: Sean Paul <seanpaul@chromium.org>
Reviewed-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Just a bit of OCD cleanup on headers - this function isn't the core
interface any more but just a helper for drivers who haven't yet
transitioned to universal planes. Put the declaration at the right
spot and sprinkle necessary #includes over all drivers.

Maybe this helps to encourage driver maintainers to do the switch.

v2: Fix #include ordering for tegra, reported by 0-day builder.

v3: Include required headers, reported by Thierry.

Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Thierry Reding <treding@nvidia.com>
Reviewed-by: NMatt Roper <matthew.d.roper@intel.com>
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

Merge tag 'drm-intel-next-2014-10-03-no-ppgtt' of git://anongit.freedesktop.org/drm-intel into drm-next

Ok, new attempt, this time around with full ppgtt disabled again.

drm-intel-next-2014-10-03:
- first batch of skl stage 1 enabling
- fixes from Rodrigo to the PSR, fbc and sink crc code
- kerneldoc for the frontbuffer tracking code, runtime pm code and the basic
  interrupt enable/disable functions
- smaller stuff all over
drm-intel-next-2014-09-19:
- bunch more i830M fixes from Ville
- full ppgtt now again enabled by default
- more ppgtt fixes from Michel Thierry and Chris Wilson
- plane config work from Gustavo Padovan
- spinlock clarifications
- piles of smaller improvements all over, as usual

* tag 'drm-intel-next-2014-10-03-no-ppgtt' of git://anongit.freedesktop.org/drm-intel: (114 commits)
  Revert "drm/i915: Enable full PPGTT on gen7"
  drm/i915: Update DRIVER_DATE to 20141003
  drm/i915: Remove the duplicated logic between the two shrink phases
  drm/i915: kerneldoc for interrupt enable/disable functions
  drm/i915: Use dev_priv instead of dev in irq setup functions
  drm/i915: s/pm._irqs_disabled/pm.irqs_enabled/
  drm/i915: Clear TX FIFO reset master override bits on chv
  drm/i915: Make sure hardware uses the correct swing margin/deemph bits on chv
  drm/i915: make sink_crc return -EIO on aux read/write failure
  drm/i915: Constify send buffer for intel_dp_aux_ch
  drm/i915: De-magic the PSR AUX message
  drm/i915: Reinstate error level message for non-simulated gpu hangs
  drm/i915: Kerneldoc for intel_runtime_pm.c
  drm/i915: Call runtime_pm_disable directly
  drm/i915: Move intel_display_set_init_power to intel_runtime_pm.c
  drm/i915: Bikeshed rpm functions name a bit.
  drm/i915: Extract intel_runtime_pm.c
  drm/i915: Remove intel_modeset_suspend_hw
  drm/i915: spelling fixes for frontbuffer tracking kerneldoc
  drm/i915: Tighting frontbuffer tracking around flips
  ...

Pull ARM SoC fixes from Olof Johansson:
 "Another week, another small batch of fixes.

  Most of these make zynq, socfpga and sunxi platforms work a bit
  better:

   - due to new requirements for regulators, DWMMC on socfpga broke past
     v3.17
   - SMP spinup fix for socfpga
   - a few DT fixes for zynq
   - another option (FIXED_REGULATOR) for sunxi is needed that used to
     be selected by other options but no longer is.
   - a couple of small DT fixes for at91
   - ...and a couple for i.MX"

* tag 'armsoc-for-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  ARM: dts: imx28-evk: Let i2c0 run at 100kHz
  ARM: i.MX6: Fix "emi" clock name typo
  ARM: multi_v7_defconfig: enable CONFIG_MMC_DW_ROCKCHIP
  ARM: sunxi_defconfig: enable CONFIG_REGULATOR_FIXED_VOLTAGE
  ARM: dts: socfpga: Add a 3.3V fixed regulator node
  ARM: dts: socfpga: Fix SD card detect
  ARM: dts: socfpga: rename gpio nodes
  ARM: at91/dt: sam9263: fix PLLB frequencies
  power: reset: at91-reset: fix power down register
  MAINTAINERS: add atmel ssc driver maintainer entry
  arm: socfpga: fix fetching cpu1start_addr for SMP
  ARM: zynq: DT: trivial: Fix mc node
  ARM: zynq: DT: Add cadence watchdog node
  ARM: zynq: DT: Add missing reference for memory-controller
  ARM: zynq: DT: Add missing reference for ADC
  ARM: zynq: DT: Add missing address for L2 pl310
  ARM: zynq: DT: Remove 222 MHz OPP
  ARM: zynq: DT: Fix GEM register area size

Pull vfs updates from Al Viro:
 "overlayfs merge + leak fix for d_splice_alias() failure exits"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  overlayfs: embed middle into overlay_readdir_data
  overlayfs: embed root into overlay_readdir_data
  overlayfs: make ovl_cache_entry->name an array instead of pointer
  overlayfs: don't hold ->i_mutex over opening the real directory
  fix inode leaks on d_splice_alias() failure exits
  fs: limit filesystem stacking depth
  overlay: overlay filesystem documentation
  overlayfs: implement show_options
  overlayfs: add statfs support
  overlay filesystem
  shmem: support RENAME_WHITEOUT
  ext4: support RENAME_WHITEOUT
  vfs: add RENAME_WHITEOUT
  vfs: add whiteout support
  vfs: export check_sticky()
  vfs: introduce clone_private_mount()
  vfs: export __inode_permission() to modules
  vfs: export do_splice_direct() to modules
  vfs: add i_op->dentry_open()

Merge tag 'imx-fixes-3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/shawnguo/linux into fixes

Merge "ARM: imx: fixes for 3.18" from Shawn Guo:

The i.MX fixes for 3.18:
 - Revert one patch which increases I2C bus frequency on imx28-evk
 - Fix a typo on imx6q EIM clock name

* tag 'imx-fixes-3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/shawnguo/linux:
  ARM: dts: imx28-evk: Let i2c0 run at 100kHz
  ARM: i.MX6: Fix "emi" clock name typo
Signed-off-by: NOlof Johansson <olof@lixom.net>

Commit 78b81f46 ("ARM: dts: imx28-evk: Run I2C0 at 400kHz") caused issues
when doing the following sequence in loop:

- Boot the kernel
- Perform audio playback
- Reboot the system via 'reboot' command

In many times the audio card cannot be probed, which causes playback to fail.

After restoring to the original i2c0 frequency of 100kHz there is no such
problem anymore.

This reverts commit 78b81f46.

Cc: <stable@vger.kernel.org> # 3.16+
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>

Fix a typo error, the "emi" names refer to the eim clocks.

The change fixes typo in EIM and EIM_SLOW pre-output dividers and
selectors clock names. Notably EIM_SLOW clock itself is named correctly.
Signed-off-by: NSteve Longerbeam <steve_longerbeam@mentor.com>
[vladimir_zapolskiy@mentor.com: ported to v3.17]
Signed-off-by: NVladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Cc: Sascha Hauer <kernel@pengutronix.de>
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>

same story...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

no sense having it a pointer - all instances have it pointing to
local variable in the same stack frame
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

just use it to serialize the assignment
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Pull MIPS fixes from Ralf Baechle:
 "This is the first round of fixes and tying up loose ends for MIPS.

   - plenty of fixes for build errors in specific obscure configurations
   - remove redundant code on the Lantiq platform
   - removal of a useless SEAD I2C driver that was causing a build issue
   - fix an earlier TLB exeption handler fix to also work on Octeon.
   - fix ISA level dependencies in FPU emulator's instruction decoding.
   - don't hardcode kernel command line in Octeon software emulator.
   - fix an earlier fix for the Loondson 2 clock setting"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
  MIPS: SEAD3: Fix I2C device registration.
  MIPS: SEAD3: Nuke PIC32 I2C driver.
  MIPS: ftrace: Fix a microMIPS build problem
  MIPS: MSP71xx: Fix build error
  MIPS: Malta: Do not build the malta-amon.c file if CMP is not enabled
  MIPS: Prevent compiler warning from cop2_{save,restore}
  MIPS: Kconfig: Add missing MIPS_CPS dependencies to PM and cpuidle
  MIPS: idle: Remove leftover __pastwait symbol and its references
  MIPS: Sibyte: Include the swarm subdir to the sb1250 LittleSur builds
  MIPS: ptrace.h: Add a missing include
  MIPS: ath79: Fix compilation error when CONFIG_PCI is disabled
  MIPS: MSP71xx: Remove compilation error when CONFIG_MIPS_MT is present
  MIPS: Octeon: Remove special case for simulator command line.
  MIPS: tlbex: Properly fix HUGE TLB Refill exception handler
  MIPS: loongson2_cpufreq: Fix CPU clock rate setting mismerge
  pci: pci-lantiq: remove duplicate check on resource
  MIPS: Lasat: Add missing CONFIG_PROC_FS dependency to PICVUE_PROC
  MIPS: cp1emu: Fix ISA restrictions for cop1x_op instructions

Pull arm64 fixes from Catalin Marinas:

 - enable 48-bit VA space now that KVM has been fixed, together with a
   couple of fixes for pgd allocation alignment and initial memblock
   current_limit.  There is still a dependency on !ARM_SMMU which needs
   to be updated as it uses the page table manipulation macros of the
   host kernel
 - eBPF fixes following changes/conflicts during the merging window
 - Compat types affecting compat_elf_prpsinfo
 - Compilation error on UP builds
 - ASLR fix when /proc/sys/kernel/randomize_va_space == 0
 - DT definitions for CLCD support on ARMv8 model platform

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: Fix memblock current_limit with 64K pages and 48-bit VA
  arm64: ASLR: Don't randomise text when randomise_va_space == 0
  arm64: vexpress: Add CLCD support to the ARMv8 model platform
  arm64: Fix compilation error on UP builds
  Documentation/arm64/memory.txt: fix typo
  net: bpf: arm64: minor fix of type in jited
  arm64: bpf: add 'load 64-bit immediate' instruction
  arm64: bpf: add 'shift by register' instructions
  net: bpf: arm64: address randomize and write protect JIT code
  arm64: mm: Correct fixmap pagetable types
  arm64: compat: fix compat types affecting struct compat_elf_prpsinfo
  arm64: Align less than PAGE_SIZE pgds naturally
  arm64: Allow 48-bits VA space without ARM_SMMU

Pull two sparc fixes from David Miller:

 1) Fix boots with gcc-4.9 compiled sparc64 kernels.

 2) Add missing __get_user_pages_fast() on sparc64 to fix hangs on
    futexes used in transparent hugepage areas.

    It's really idiotic to have a weak symbolled fallback that just
    returns zero, and causes this kind of bug.  There should be no
    backup implementation and the link should fail if the architecture
    fails to provide __get_user_pages_fast() and supports transparent
    hugepages.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  sparc64: Implement __get_user_pages_fast().
  sparc64: Fix register corruption in top-most kernel stack frame during boot.

Pull kvm fixes from Paolo Bonzini:
 "This is a pretty large update.  I think it is roughly as big as what I
  usually had for the _whole_ rc period.

  There are a few bad bugs where the guest can OOPS or crash the host.
  We have also started looking at attack models for nested
  virtualization; bugs that usually result in the guest ring 0 crashing
  itself become more worrisome if you have nested virtualization,
  because the nested guest might bring down the non-nested guest as
  well.  For current uses of nested virtualization these do not really
  have a security impact, but you never know and bugs are bugs
  nevertheless.

  A lot of these bugs are in 3.17 too, resulting in a large number of
  stable@ Ccs.  I checked that all the patches apply there with no
  conflicts"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  kvm: vfio: fix unregister kvm_device_ops of vfio
  KVM: x86: Wrong assertion on paging_tmpl.h
  kvm: fix excessive pages un-pinning in kvm_iommu_map error path.
  KVM: x86: PREFETCH and HINT_NOP should have SrcMem flag
  KVM: x86: Emulator does not decode clflush well
  KVM: emulate: avoid accessing NULL ctxt->memopp
  KVM: x86: Decoding guest instructions which cross page boundary may fail
  kvm: x86: don't kill guest on unknown exit reason
  kvm: vmx: handle invvpid vm exit gracefully
  KVM: x86: Handle errors when RIP is set during far jumps
  KVM: x86: Emulator fixes for eip canonical checks on near branches
  KVM: x86: Fix wrong masking on relative jump/call
  KVM: x86: Improve thread safety in pit
  KVM: x86: Prevent host from panicking on shared MSR writes.
  KVM: x86: Check non-canonical addresses upon WRMSR

Merge tag 'stable/for-linus-3.18-b-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen bug fixes from David Vrabel:

 - Fix regression in xen_clocksource_read() which caused all Xen guests
   to crash early in boot.
 - Several fixes for super rare race conditions in the p2m.
 - Assorted other minor fixes.

* tag 'stable/for-linus-3.18-b-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/pci: Allocate memory for physdev_pci_device_add's optarr
  x86/xen: panic on bad Xen-provided memory map
  x86/xen: Fix incorrect per_cpu accessor in xen_clocksource_read()
  x86/xen: avoid race in p2m handling
  x86/xen: delay construction of mfn_list_list
  x86/xen: avoid writing to freed memory after race in p2m handling
  xen/balloon: Don't continue ballooning when BP_ECANCELED is encountered

Pull sound fixes from Takashi Iwai:
 "Here are a chunk of small fixes since rc1: two PCM core fixes, one is
  a long-standing annoyance about lockdep and another is an ARM64 mmap
  fix.

  The rest are a HD-audio HDMI hotplug notification fix, a fix for
  missing NULL termination in Realtek codec quirks and a few new
  device/codec-specific quirks as usual"

* tag 'sound-3.18-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda - Add missing terminating entry to SND_HDA_PIN_QUIRK macro
  ALSA: pcm: Fix false lockdep warnings
  ALSA: hda - Fix inverted LED gpio setup for Lenovo Ideapad
  ALSA: hda - hdmi: Fix missing ELD change event on plug/unplug
  ALSA: usb-audio: Add support for Steinberg UR22 USB interface
  ALSA: ALC283 codec - Avoid pop noise on headphones during suspend/resume
  ALSA: pcm: use the same dma mmap codepath both for arm and arm64

Pull /dev/random updates from Ted Ts'o:
 "This adds a memzero_explicit() call which is guaranteed not to be
  optimized away by GCC.  This is important when we are wiping
  cryptographically sensitive material"

* tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random:
  crypto: memzero_explicit - make sure to clear out sensitive data
  random: add and use memzero_explicit() for clearing data

Pull ACPI and power management updates from Rafael Wysocki:
 "This is material that didn't make it to my 3.18-rc1 pull request for
  various reasons, mostly related to timing and travel (LinuxCon EU /
  LPC) plus a couple of fixes for recent bugs.

  The only really new thing here is the PM QoS class for memory
  bandwidth, but it is simple enough and users of it will be added in
  the next cycle.  One major change in behavior is that platform devices
  enumerated by ACPI will use 32-bit DMA mask by default.  Also included
  is an ACPICA update to a new upstream release, but that's mostly
  cleanups, changes in tools and similar.  The rest is fixes and
  cleanups mostly.

  Specifics:

   - Fix for a recent PCI power management change that overlooked the
     fact that some IRQ chips might not be able to configure PCIe PME
     for system wakeup from Lucas Stach.

   - Fix for a bug introduced in 3.17 where acpi_device_wakeup() is
     called with a wrong ordering of arguments from Zhang Rui.

   - A bunch of intel_pstate driver fixes (all -stable candidates) from
     Dirk Brandewie, Gabriele Mazzotta and Pali Rohár.

   - Fixes for a rather long-standing problem with the OOM killer and
     the freezer that frozen processes killed by the OOM do not actually
     release any memory until they are thawed, so OOM-killing them is
     rather pointless, with a couple of cleanups on top (Michal Hocko,
     Cong Wang, Rafael J Wysocki).

   - ACPICA update to upstream release 20140926, inlcuding mostly
     cleanups reducing differences between the upstream ACPICA and the
     kernel code, tools changes (acpidump, acpiexec) and support for the
     _DDN object (Bob Moore, Lv Zheng).

   - New PM QoS class for memory bandwidth from Tomeu Vizoso.

   - Default 32-bit DMA mask for platform devices enumerated by ACPI
     (this change is mostly needed for some drivers development in
     progress targeted at 3.19) from Heikki Krogerus.

   - ACPI EC driver cleanups, mostly related to debugging, from Lv
     Zheng.

   - cpufreq-dt driver updates from Thomas Petazzoni.

   - powernv cpuidle driver update from Preeti U Murthy"

* tag 'pm+acpi-3.18-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (34 commits)
  intel_pstate: Correct BYT VID values.
  intel_pstate: Fix BYT frequency reporting
  intel_pstate: Don't lose sysfs settings during cpu offline
  cpufreq: intel_pstate: Reflect current no_turbo state correctly
  cpufreq: expose scaling_cur_freq sysfs file for set_policy() drivers
  cpufreq: intel_pstate: Fix setting max_perf_pct in performance policy
  PCI / PM: handle failure to enable wakeup on PCIe PME
  ACPI: invoke acpi_device_wakeup() with correct parameters
  PM / freezer: Clean up code after recent fixes
  PM: convert do_each_thread to for_each_process_thread
  OOM, PM: OOM killed task shouldn't escape PM suspend
  freezer: remove obsolete comments in __thaw_task()
  freezer: Do not freeze tasks killed by OOM killer
  ACPI / platform: provide default DMA mask
  cpuidle: powernv: Populate cpuidle state details by querying the device-tree
  cpufreq: cpufreq-dt: adjust message related to regulators
  cpufreq: cpufreq-dt: extend with platform_data
  cpufreq: allow driver-specific data
  ACPI / EC: Cleanup coding style.
  ACPI / EC: Refine event/query debugging messages.
  ...

Pull thermal management updates from Zhang Rui:
 "Sorry that I missed the merge window as there is a bug found in the
  last minute, and I have to fix it and wait for the code to be tested
  in linux-next tree for a few days.  Now the buggy patch has been
  dropped entirely from my next branch.  Thus I hope those changes can
  still be merged in 3.18-rc2 as most of them are platform thermal
  driver changes.

  Specifics:

   - introduce ACPI INT340X thermal drivers.

     Newer laptops and tablets may have thermal sensors and other
     devices with thermal control capabilities that are exposed for the
     OS to use via the ACPI INT340x device objects.  Several drivers are
     introduced to expose the temperature information and cooling
     ability from these objects to user-space via the normal thermal
     framework.

     From: Lu Aaron, Lan Tianyu, Jacob Pan and Zhang Rui.

   - introduce a new thermal governor, which just uses a hysteresis to
     switch abruptly on/off a cooling device.  This governor can be used
     to control certain fan devices that can not be throttled but just
     switched on or off.  From: Peter Feuerer.

   - introduce support for some new thermal interrupt functions on
     i.MX6SX, in IMX thermal driver.  From: Anson, Huang.

   - introduce tracing support on thermal framework.  From: Punit
     Agrawal.

   - small fixes in OF thermal and thermal step_wise governor"

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux: (25 commits)
  Thermal: int340x thermal: select ACPI fan driver
  Thermal: int3400_thermal: use acpi_thermal_rel parsing APIs
  Thermal: int340x_thermal: expose acpi thermal relationship tables
  Thermal: introduce int3403 thermal driver
  Thermal: introduce INT3402 thermal driver
  Thermal: move the KELVIN_TO_MILLICELSIUS macro to thermal.h
  ACPI / Fan: support INT3404 thermal device
  ACPI / Fan: add ACPI 4.0 style fan support
  ACPI / fan: convert to platform driver
  ACPI / fan: use acpi_device_xxx_power instead of acpi_bus equivelant
  ACPI / fan: remove no need check for device pointer
  ACPI / fan: remove unused macro
  Thermal: int3400 thermal: register to thermal framework
  Thermal: int3400 thermal: add capability to detect supporting UUIDs
  Thermal: introduce int3400 thermal driver
  ACPI: add ACPI_TYPE_LOCAL_REFERENCE support to acpi_extract_package()
  ACPI: make acpi_create_platform_device() an external API
  thermal: step_wise: fix: Prevent from binary overflow when trend is dropping
  ACPI: introduce ACPI int340x thermal scan handler
  thermal: Added Bang-bang thermal governor
  ...

With 48-bit VA space, the 64K page configuration uses 3 levels instead
of 2 and PUD_SIZE != PMD_SIZE. Since with 64K pages we only cover
PMD_SIZE with the initial swapper_pg_dir populated in head.S, the
memblock current_limit needs to be set accordingly in map_mem() to avoid
allocating unmapped memory. The memblock current_limit is progressively
increased as more blocks are mapped.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

It is not sufficient to only implement get_user_pages_fast(), you
must also implement the atomic version __get_user_pages_fast()
otherwise you end up using the weak symbol fallback implementation
which simply returns zero.

This is dangerous, because it causes the futex code to loop forever
if transparent hugepages are supported (see get_futex_key()).
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Meelis Roos reported that kernels built with gcc-4.9 do not boot, we
eventually narrowed this down to only impacting machines using
UltraSPARC-III and derivitive cpus.

The crash happens right when the first user process is spawned:

[   54.451346] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000004
[   54.451346]
[   54.571516] CPU: 1 PID: 1 Comm: init Not tainted 3.16.0-rc2-00211-gd7933ab7 #96
[   54.666431] Call Trace:
[   54.698453]  [0000000000762f8c] panic+0xb0/0x224
[   54.759071]  [000000000045cf68] do_exit+0x948/0x960
[   54.823123]  [000000000042cbc0] fault_in_user_windows+0xe0/0x100
[   54.902036]  [0000000000404ad0] __handle_user_windows+0x0/0x10
[   54.978662] Press Stop-A (L1-A) to return to the boot prom
[   55.050713] ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000004

Further investigation showed that compiling only per_cpu_patch() with
an older compiler fixes the boot.

Detailed analysis showed that the function is not being miscompiled by
gcc-4.9, but it is using a different register allocation ordering.

With the gcc-4.9 compiled function, something during the code patching
causes some of the %i* input registers to get corrupted.  Perhaps
we have a TLB miss path into the firmware that is deep enough to
cause a register window spill and subsequent restore when we get
back from the TLB miss trap.

Let's plug this up by doing two things:

1) Stop using the firmware stack for client interface calls into
   the firmware.  Just use the kernel's stack.

2) As soon as we can, call into a new function "start_early_boot()"
   to put a one-register-window buffer between the firmware's
   deepest stack frame and the top-most initial kernel one.
Reported-by: NMeelis Roos <mroos@linux.ee>
Tested-by: NMeelis Roos <mroos@linux.ee>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When user asks to turn off ASLR by writing "0" to
/proc/sys/kernel/randomize_va_space there should not be
any randomization to mmap base, stack, VDSO, libs, text and heap

Currently arm64 violates this behavior by randomising text.
Fix this by defining a constant ELF_ET_DYN_BASE. The randomisation of
mm->mmap_base is done by setup_new_exec -> arch_pick_mmap_layout ->
mmap_base -> mmap_rnd.
Signed-off-by: NArun Chandran <achandran@mvista.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

This reverts commit 8c50f10d.

It's not yet solid and Dave objected to pulling the tree in its
current state.

Cc: Michel Thierry <michel.thierry@intel.com>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
References: http://mid.mail-archive.com/CAPM=9ty2r1MLE=wzC-_vNSUzXVqAyXiGgocpSV9qOp0gzpK3xA@mail.gmail.com
References: http://lists.freedesktop.org/archives/intel-gfx/2014-October/053926.htmlAcked-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>