Make use of lists instead of kfifo in order to dynamically allocate
task entry when someone require some delayed work, and thus preventing
drm_flip_work_queue from directly calling func instead of queuing this
call.
This allow drm_flip_work_queue to be safely called even within irq
handlers.

Add new helper functions to allocate a flip work task and queue it when
needed. This prevents allocating data within irq context (which might
impact the time spent in the irq handler).
Signed-off-by: NBoris BREZILLON <boris.brezillon@free-electrons.com>
Reviewed-by: NRob Clark <robdclark@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Turned out to be much simpler on top of my latest atomic stuff than
what I've feared. Some details:

- Drop the modeset_lock_all snakeoil in drm_plane_init. Same
  justification as for the equivalent change in drm_crtc_init done in

	commit d0fa1af4
	Author: Daniel Vetter <daniel.vetter@ffwll.ch>
	Date:   Mon Sep 8 09:02:49 2014 +0200

	    drm: Drop modeset locking from crtc init function

  Without these the drm_modeset_lock_init would fall over the exact
  same way.

- Since the atomic core code wraps the locking switching it to
  per-plane locks was a one-line change.

- For the legacy ioctls add a plane argument to the locking helper so
  that we can grab the right plane lock (cursor or primary). Since the
  universal cursor plane might not be there, or someone really crazy
  might forgoe the primary plane even accept NULL.

- Add some locking WARN_ON to the atomic helpers for good paranoid
  measure and to check that it all works out.

Tested on my exynos atomic hackfest with full lockdep checks and ww
backoff injection.

v2: I've forgotten about the load-detect code in i915.

v3: Thierry reported that in latest 3.18-rc vmwgfx doesn't compile any
more due to

commit 21e88620
Author: Rob Clark <robdclark@gmail.com>
Date:   Thu Oct 30 13:39:04 2014 -0400

    drm/vmwgfx: fix lock breakage

Rebased and fix this up.

Cc: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NDave Airlie <airlied@redhat.com>

v1: original
v2: danvet's kerneldoc nitpicks
Signed-off-by: NRob Clark <robdclark@gmail.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDave Airlie <airlied@redhat.com>

So my original plan was that the drm core refcounts framebuffers like
with the legacy ioctls. But that doesn't work for a bunch of reasons:

- State objects might live longer than until the next fb change
  happens for a plane. For example delayed cleanup work only happens
  _after_ the pageflip ioctl has completed. So this definitely doesn't
  work without the plane state holding its own references.

- The other issue is transition from legacy to atomic implementations,
  where the driver works under a mix of both worlds. Which means
  legacy paths might not properly update the ->fb pointer under
  plane->state->fb. Which is a bit a problem when then someone comes
  around and _does_ try to clean it up when it's long gone.

The second issue is just a bit a transition bug, since drivers should
update plane->state->fb in all the paths that aren't converted yet.
But a bit more robustness for the transition can't hurt - we pull
similar tricks with cleaning up the old fb in the transitional helpers
already.

The pattern for drivers that transition is

	if (plane->state)
		drm_atomic_set_fb_for_plane(plane->state, plane->fb);

inserted after the fb update has logically completed at the end of
->set_config (or ->set_base/mode_set if using the crtc helpers),
->page_flip, ->update_plane or any other entry point which updates
plane->fb.

v2: Update kerneldoc - copypasta fail.

v3: Fix spelling in the commit message (Sean).
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

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>

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>

acpi_pci_get_bridge_handle() returns the ACPI handle for the bridge device
(either a host bridge or a PCI-to-PCI bridge) leading to a PCI bus.  But
SR-IOV virtual functions can be on a virtual bus with no bridge leading to
it.  Return a NULL acpi_handle in this case instead of trying to
dereference the NULL pointer to the bridge.

This fixes a NULL pointer dereference oops in pci_get_hp_params() when
adding SR-IOV VF devices on virtual buses.

[bhelgaas: changelog, add comment in code]
Fixes: 6cd33649 ("PCI: Add pci_configure_device() during enumeration")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=87591Reported-by: NChao Zhou <chao.zhou@intel.com>
Reported-by: NJoerg Roedel <joro@8bytes.org>
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

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>

In the interest of reducing magic numbers and having to cross check with
the specs all the time.
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

These counters are used for Displayort compliance testing to detect error
conditions when executing tests 4.2.2.4 and 4.2.2.5 in the Displayport Link
CTS specificaiton. They determine whether to use the preferred/requested
mode or the failsafe mode during these tests.

V2:
- Addressed previous review feedback
- Updated commit message
- Changed from uint8_t to uint32_t

Cc: dri-devel@lists.freedesktop.org
Signed-off-by: NTodd Previte <tprevite@gmail.com>
[danvet: s/uint32_t/unsigned/ for clearer intent. Also drop the i915
from the subject, it's all core stuff.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

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>

The string property read helpers will run off the end of the buffer if
it is handed a malformed string property. Rework the parsers to make
sure that doesn't happen. At the same time add new test cases to make
sure the functions behave themselves.

The original implementations of of_property_read_string_index() and
of_property_count_strings() both open-coded the same block of parsing
code, each with it's own subtly different bugs. The fix here merges
functions into a single helper and makes the original functions static
inline wrappers around the helper.

One non-bugfix aspect of this patch is the addition of a new wrapper,
of_property_read_string_array(). The new wrapper is needed by the
device_properties feature that Rafael is working on and planning to
merge for v3.19. The implementation is identical both with and without
the new static inline wrapper, so it just got left in to reduce the
churn on the header file.
Signed-off-by: NGrant Likely <grant.likely@linaro.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Darren Hart <darren.hart@intel.com>
Cc: <stable@vger.kernel.org>  # v3.3+: Drop selftest hunks that don't apply

So far, the required PLL's (PLL1/PLL2/PLL5) have been initialized
by boot loader and the kernel code defined fixed rates according
to those default configurations. Beginning with the USB PLL7 the
code started to initialize the PLL's itself (using imx_clk_pllv3).

However, since commit dc4805c2
(ARM: imx: remove ENABLE and BYPASS bits from clk-pllv3 driver)
imx_clk_pllv3 no longer takes care of the ENABLE and BYPASS bits,
hence the USB PLL were not configured correctly anymore.

This patch not only fixes those USB PLL's, but also makes use of
the imx_clk_pllv3 for all PLL's and alignes the code with the PLL
support of the i.MX6 series.
Signed-off-by: NStefan Agner <stefan@agner.ch>
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>

That can be reused by the reject bridge expression to build the reject
packet. The new functions are:

* nf_reject_ip6_tcphdr_get(): to sanitize and to obtain the TCP header.
* nf_reject_ip6hdr_put(): to build the IPv6 header.
* nf_reject_ip6_tcphdr_put(): to build the TCP header.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

That can be reused by the reject bridge expression to build the reject
packet. The new functions are:

* nf_reject_ip_tcphdr_get(): to sanitize and to obtain the TCP header.
* nf_reject_iphdr_put(): to build the IPv4 header.
* nf_reject_ip_tcphdr_put(): to build the TCP header.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Author: David Jeffery <djeffery@redhat.com>
Changes to the basic direct I/O code have broken the raw driver when reading
to the end of a raw device.  Instead of returning a short read for a read that
extends partially beyond the device's end or 0 when at the end of the device,
these reads now return EIO.

The raw driver needs the same end of device handling as was added for normal
block devices.  Using blkdev_read_iter, which has the needed size checks,
prevents the EIO conditions at the end of the device.
Signed-off-by: NDavid Jeffery <djeffery@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

UFO is now disabled on all drivers that work with virtio net headers,
but userland may try to send UFO/IPv6 packets anyway.  Instead of
sending with ID=0, we should select identifiers on their behalf (as we
used to).
Signed-off-by: NBen Hutchings <ben@decadent.org.uk>
Fixes: 916e4cf4 ("ipv6: reuse ip6_frag_id from ip6_ufo_append_data")
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some drivers are unable to perform TX completions in a bound time.
They instead call skb_orphan()

Problem is skb_fclone_busy() has to detect this case, otherwise
we block TCP retransmits and can freeze unlucky tcp sessions on
mostly idle hosts.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Fixes: 1f3279ae ("tcp: avoid retransmits of TCP packets hanging in host queues")
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 0a31bc97 ("mm: memcontrol: rewrite uncharge API") changed
page migration to uncharge the old page right away.  The page is locked,
unmapped, truncated, and off the LRU, but it could race with writeback
ending, which then doesn't unaccount the page properly:

test_clear_page_writeback()              migration
                                           wait_on_page_writeback()
  TestClearPageWriteback()
                                           mem_cgroup_migrate()
                                             clear PCG_USED
  mem_cgroup_update_page_stat()
    if (PageCgroupUsed(pc))
      decrease memcg pages under writeback

  release pc->mem_cgroup->move_lock

The per-page statistics interface is heavily optimized to avoid a
function call and a lookup_page_cgroup() in the file unmap fast path,
which means it doesn't verify whether a page is still charged before
clearing PageWriteback() and it has to do it in the stat update later.

Rework it so that it looks up the page's memcg once at the beginning of
the transaction and then uses it throughout.  The charge will be
verified before clearing PageWriteback() and migration can't uncharge
the page as long as that is still set.  The RCU lock will protect the
memcg past uncharge.

As far as losing the optimization goes, the following test results are
from a microbenchmark that maps, faults, and unmaps a 4GB sparse file
three times in a nested fashion, so that there are two negative passes
that don't account but still go through the new transaction overhead.
There is no actual difference:

 old:     33.195102545 seconds time elapsed       ( +-  0.01% )
 new:     33.199231369 seconds time elapsed       ( +-  0.03% )

The time spent in page_remove_rmap()'s callees still adds up to the
same, but the time spent in the function itself seems reduced:

     # Children      Self  Command        Shared Object       Symbol
 old:     0.12%     0.11%  filemapstress  [kernel.kallsyms]   [k] page_remove_rmap
 new:     0.12%     0.08%  filemapstress  [kernel.kallsyms]   [k] page_remove_rmap
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NMichal Hocko <mhocko@suse.cz>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Cc: <stable@vger.kernel.org>	[3.17.x]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

A follow-up patch would have changed the call signature.  To save the
trouble, just fold it instead.
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NMichal Hocko <mhocko@suse.cz>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Cc: <stable@vger.kernel.org>	[3.17.x]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If an anonymous mapping is not allowed to fault thp memory and then
madvise(MADV_HUGEPAGE) is used after fault, khugepaged will never
collapse this memory into thp memory.

This occurs because the madvise(2) handler for thp, hugepage_madvise(),
clears VM_NOHUGEPAGE on the stack and it isn't stored in vma->vm_flags
until the final action of madvise_behavior().  This causes the
khugepaged_enter_vma_merge() to be a no-op in hugepage_madvise() when
the vma had previously had VM_NOHUGEPAGE set.

Fix this by passing the correct vma flags to the khugepaged mm slot
handler.  There's no chance khugepaged can run on this vma until after
madvise_behavior() returns since we hold mm->mmap_sem.

It would be possible to clear VM_NOHUGEPAGE directly from vma->vm_flags
in hugepage_advise(), but I didn't want to introduce special case
behavior into madvise_behavior().  I think it's best to just let it
always set vma->vm_flags itself.
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Reported-by: NSuleiman Souhlal <suleiman@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Driver calling of_reserved_mem_device_init() might be interested if the
initialization has been successful or not, so add support for returning
error code.

This fixes a build warining caused by commit 7bfa5ab6 ("drivers:
dma-coherent: add initialization from device tree"), which has been
merged without this change and without fixing function return value.

Fixes: 7bfa5ab6 ("drivers: dma-coherent: add initialization from device tree")
Signed-off-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Laura Abbott <lauraa@codeaurora.org>
Cc: Josh Cartwright <joshc@codeaurora.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 4eaf99be switched to returning bool and as a result reversed
the logic of the integrity merge checks.  However, the empty stubs used
when the block integrity code is compiled out were still returning
0. Make these stubs return "true".
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Reported-by: NMichael L. Semon <mlsemon35@gmail.com>
Tested-by: NMichael L. Semon <mlsemon35@gmail.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

In an overlay directory that shadows an empty lower directory, say
/mnt/a/empty102, do:

 	touch /mnt/a/empty102/x
 	unlink /mnt/a/empty102/x
 	rmdir /mnt/a/empty102

It's actually harmless, but needs another level of nesting between
I_MUTEX_CHILD and I_MUTEX_NORMAL.
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
Tested-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Although rcu_dereference() and friends can be used in situations where
object lifetimes are being managed by something other than RCU, the
resulting sparse and lockdep-RCU noise can be annoying.  This commit
therefore supplies a lockless_dereference(), which provides the
protection for dereferences without the RCU-related debugging noise.
Reported-by: NAl Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

To delegate promiscuous mode and multicast filtering to the subdriver.
Signed-off-by: NOlivier Blin <olivier.blin@softathome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix kernel-doc warning in <linux/skbuff.h> by making both headers_start
and headers_end private fields.

Warning(..//include/linux/skbuff.h:654): No description found for parameter 'headers_end[0]'
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 35ce7f29 (rcu: Create rcuo kthreads only for onlined CPUs)
avoids creating rcuo kthreads for CPUs that never come online.  This
fixes a bug in many instances of firmware: Instead of lying about their
age, these systems instead lie about the number of CPUs that they have.
Before commit 35ce7f29, this could result in huge numbers of useless
rcuo kthreads being created.

It appears that experience indicates that I should have told the
people suffering from this problem to fix their broken firmware, but
I instead produced what turned out to be a partial fix.   The missing
piece supplied by this commit makes sure that rcu_barrier() knows not to
post callbacks for no-CBs CPUs that have not yet come online, because
otherwise rcu_barrier() will hang on systems having firmware that lies
about the number of CPUs.

It is tempting to simply have rcu_barrier() refuse to post a callback on
any no-CBs CPU that does not have an rcuo kthread.  This unfortunately
does not work because rcu_barrier() is required to wait for all pending
callbacks.  It is therefore required to wait even for those callbacks
that cannot possibly be invoked.  Even if doing so hangs the system.

Given that posting a callback to a no-CBs CPU that does not yet have an
rcuo kthread can hang rcu_barrier(), It is tempting to report an error
in this case.  Unfortunately, this will result in false positives at
boot time, when it is perfectly legal to post callbacks to the boot CPU
before the scheduler has started, in other words, before it is legal
to invoke rcu_barrier().

So this commit instead has rcu_barrier() avoid posting callbacks to
CPUs having neither rcuo kthread nor pending callbacks, and has it
complain bitterly if it finds CPUs having no rcuo kthread but some
pending callbacks.  And when rcu_barrier() does find CPUs having no rcuo
kthread but pending callbacks, as noted earlier, it has no choice but
to hang indefinitely.
Reported-by: NYanko Kaneti <yaneti@declera.com>
Reported-by: NJay Vosburgh <jay.vosburgh@canonical.com>
Reported-by: NMeelis Roos <mroos@linux.ee>
Reported-by: NEric B Munson <emunson@akamai.com>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: NEric B Munson <emunson@akamai.com>
Tested-by: NJay Vosburgh <jay.vosburgh@canonical.com>
Tested-by: NYanko Kaneti <yaneti@declera.com>
Tested-by: NKevin Fenzi <kevin@scrye.com>
Tested-by: NMeelis Roos <mroos@linux.ee>

0x4c6e is a secondary device id so should not be used
by the driver.
Noticed-by: NMark Kettenis <mark.kettenis@xs4all.nl>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

The bug referenced by the comment in this commit was not
completely fixed in GCC 4.8.2, as I mentioned in a thread back
in February:

   https://lkml.org/lkml/2014/2/12/797

The conclusion at that time was to make the quirk unconditional
until the bug could be found and fixed in GCC. Unfortunately,
when I submitted the patch (commit a9f18034) I left a comment
in that claimed the bug was fixed in GCC 4.8.2+.

This comment is inaccurate, and should be removed.
Signed-off-by: NSteven Noonan <steven@uplinklabs.net>
Signed-off-by: NIngo Molnar <mingo@kernel.org>
Cc: Jakub Jelinek <jakub@redhat.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1414274982-14040-1-git-send-email-steven@uplinklabs.net
Cc: Ingo Molnar <mingo@kernel.org>