Tvrtko spotted a stale reference to b->lock (now b->rb_lock) so review
the comments and try to improve them in passing.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170315222259.1469-1-chris@chris-wilson.co.ukReviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

Check that request has not been signaled before acquiring a reference to
the request for signaling later in the interrupt handler.

The loading of the cacheline (for request->fence.flags) should be "free"
when followed by the locked increment of the request->fence.refcount
(which then sets the cacheline to exclusive mode), i.e. the cost of
test_bit prior to an atomic_inc should be negligible. This should
benefit us when we have a pile of bare breadcrumbs (interrupted execbuf)
where we may get interrupts faster than we can get rid of the
intel_wait, or if the device is too slow to run the bottom-half between
interrupts.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170315210726.12095-5-chris@chris-wilson.co.uk

We need to ensure that we always serialize updates to the bottom-half
using the breadcrumbs.irq_lock so that we don't race with a concurrent
interrupt handler. This is most important just prior to leaving the
waiter (when the intel_wait will be overwritten), so make sure we are
not the current bottom-half when skipping the irq locks.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170315210726.12095-4-chris@chris-wilson.co.uk

Before walking the rbtree of waiters (marking them as complete and waking
them), decouple the interrupt handler. This prevents a race between the
missed waiter waking up and removing its intel_wait (which skips
checking the lock) and the interrupt handler dereferencing the
intel_wait. (Though we do not expect to encounter waiters during idle!)

Fixes: e1c0c91b ("drm/i915: Wake up all waiters before idling")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170315210726.12095-3-chris@chris-wilson.co.uk

When adding a new request to the breadcrumb rbtree, we mark all those
requests inside the rbtree that are already completed as complete. This
wakes those waiters up and allows them to skip the spinlock before
returning to userspace. If one of those is the current bottom-half and
allocated its intel_wait on the stack, it may then overwrite the
b->irq_wait upon exiting i915_wait_request() just as the interrupt handler
dereferences it.

Fixes: 56299fb7 ("drm/i915: Signal first fence from irq handler if complete")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170315210726.12095-2-chris@chris-wilson.co.uk

Since commit 9b6586ae ("drm/i915: Keep a global seqno per-engine")
converted intel_breadcrumbs_busy() to reporting a single boolean, we
need only compute a boolean internally (and not needlessly compute the
flag).
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170315210726.12095-1-chris@chris-wilson.co.uk

We take the runtime pm wakelock during i915_handle_error() to ensure
that all paths that reach the error handler keep the device awake during
the hw reads. However, we need to extend that from the reset handler to
include the earlier capture routines.
Reported-by: Antonio Argenziano <antonio.argenziano@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michel Thierry <michel.thierry@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170314171840.25706-1-chris@chris-wilson.co.ukReviewed-by: Michel Thierry <michel.thierry@intel.com>

Manual pointer manipulation is error prone. Let compiler calculate
right offsets for us in case we need to change ads layout.

v2: don't call it object (Chris)
v3: restyle offset assignments (Chris)
v4: stylistic reductions
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Oscar Mateo <oscar.mateo@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170314133309.126432-1-michal.wajdeczko@intel.comSigned-off-by: Chris Wilson <chris@chris-wilson.co.uk>

`guc_firmware_path` and `huc_firmware_path` module parameters are added.

Using the parameter disables version checks and loads desired firmware
instead of the default one.

v2: make params unsafe && notice about disabled fw check (J. Lahtinen)

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Michal Winiarski <michal.winiarski@intel.com>
Signed-off-by: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

intel_{h,g}uc_init_fw selects correct firmware and then triggers it's
preparation (fetch + initial parsing).

This change separates out select steps, so those can be called by
the sanitize_options().

Then, during the init_fw(), we prepare the firmware if the firmware was
selected.

Cc: Michal Winiarski <michal.winiarski@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

Currently fw->path values can represent one of three possible states:

 1) NULL - device without the uC
 2) '\0' - device with the uC but have no firmware
 3) else - device with the uC and we have firmware

Second case is used only to WARN at a later stage.

We can WARN right away and merge cases 1 and 2.

Code can be even further simplified and common (HuC/GuC logic) happening
right before the fetch can be offloaded to the common function.

v2: fewer temporary variables, more straightforward flow (M. Wajdeczko)
v3: DRM_ERROR instead of WARN (M. Wajdeczko)
v4: coding standard (J. Lahtinen)
v5: non-trivial rebase
v6: remove path check, we are checking fetch status (M. Wajdeczko)

Cc: Anusha Srivatsa <anusha.srivatsa@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Michal Winiarski <michal.winiarski@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

Current version of intel_guc_init_hw() does a lot:
 - cares about submission
 - loads huc
 - implement WA

This change offloads some of the logic to intel_uc_init_hw(), which now
cares about the above.

v2: rename guc_hw_reset and fix typo in define name (M. Wajdeczko)
v3: rename once again
v4: remove spurious comments and add some style (J. Lahtinen)
v5: flow changes, got rid of dead checks (M. Wajdeczko)
v6: rebase
v7: rebase & onion teardown (J. Lahtinen)

Cc: Anusha Srivatsa <anusha.srivatsa@intel.com>
Cc: Michal Winiarski <michal.winiarski@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

Let intel_guc_init_fw() focus on determining and fetching the correct
firmware.

This patch introduces intel_uc_sanitize_options() that is called from
intel_sanitize_options().

Then, if we have GuC, we can call intel_guc_init_fw() conditionally
and we do not have to do the internal checks.

v2: fix comment, notify when nuking GuC explicitly enabled (M. Wajdeczko)
v3: fix comment again, change the nuke message (M. Wajdeczko)
v4: update title to reflect new function name + rebase
v5: text && remove 2 uneccessary checks (M. Wajdeczko)

Cc: Michal Winiarski <michal.winiarski@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

Instead of calling intel_guc_init() and intel_huc_init() one by one this
patch introduces intel_uc_init_fw() function that calls them both.

Called functions are renamed accordingly.

Trying to have subject_verb_object ordering and more descriptive names,
the intel_huc_init() and intel_guc_init() functions are renamed.

For guc_init():
 * `intel_guc` is the subject, so those functions now take intel_guc
   structure, instead of the dev_priv
 * init is the verb
 * fw is the object which better describes the function's role

huc_init() change follows the same reasoning.

v2: settle on intel_uc_fetch_fw name (M. Wajdeczko)
v3: yet another rename - intel_uc_init_fw (J. Lahtinen)
v4: non-trivial rebase

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Michal Winiarski <michal.winiarski@intel.com>
Signed-off-by: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

The file fits better.

Additionally rename it to intel_uc_prepare_fw(), as the function does
more than simple fetch.

`obj` cleanup in the function is also fixed (i.e. removed). In the fail
scenario it was always 'put' but there's no possible flow that
initializes the obj properly and then goes to the fail label.

v2: remove second declaration, reorder (M. Wajdeczko)
v3: non-trivial rebase
v4: remove obj cleanup in the fail scenario (C. Wilson)

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

GuC historically has two "startup" functions called _init() and _setup()

Then HuC came with it's _init() and _load().

This commit renames intel_guc_setup() and intel_huc_load() to
*uc_init_hw() as they called from the i915_gem_init_hw().

The aim is to be consistent in that entry points called during
particular driver init phases (e.g. init_hw) are all suffixed by that
phase. When reading the leaf functions, it should be clear at what stage
during the driver load it is called and therefore what operations are
legal at that point.

Also, since the functions start with intel_guc and intel_huc they take
appropiate structure.

v2: commit message update (Chris Wilson)
v3: change taken parameters to be more "semantic" (M. Wajdeczko)

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michal Winiarski <michal.winiarski@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

Used to obtain "dev_priv" from huc struct pointer.
We already have similar thing for guc.

Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

Externs are implicit and we generally try to avoid them.

Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

The rcu_barrier() takes the cpu_hotplug mutex which itself is not
reclaim-safe, and so rcu_barrier() is illegal from inside the shrinker.

[  309.661373] =========================================================
[  309.661376] [ INFO: possible irq lock inversion dependency detected ]
[  309.661380] 4.11.0-rc1-CI-CI_DRM_2333+ #1 Tainted: G        W
[  309.661383] ---------------------------------------------------------
[  309.661386] gem_exec_gttfil/6435 just changed the state of lock:
[  309.661389]  (rcu_preempt_state.barrier_mutex){+.+.-.}, at: [<ffffffff81100731>] _rcu_barrier+0x31/0x160
[  309.661399] but this lock took another, RECLAIM_FS-unsafe lock in the past:
[  309.661402]  (cpu_hotplug.lock){+.+.+.}
[  309.661404]

               and interrupts could create inverse lock ordering between them.

[  309.661410]
               other info that might help us debug this:
[  309.661414]  Possible interrupt unsafe locking scenario:

[  309.661417]        CPU0                    CPU1
[  309.661419]        ----                    ----
[  309.661421]   lock(cpu_hotplug.lock);
[  309.661425]                                local_irq_disable();
[  309.661432]                                lock(rcu_preempt_state.barrier_mutex);
[  309.661441]                                lock(cpu_hotplug.lock);
[  309.661446]   <Interrupt>
[  309.661448]     lock(rcu_preempt_state.barrier_mutex);
[  309.661453]
                *** DEADLOCK ***

[  309.661460] 4 locks held by gem_exec_gttfil/6435:
[  309.661464]  #0:  (sb_writers#10){.+.+.+}, at: [<ffffffff8120d83d>] vfs_write+0x17d/0x1f0
[  309.661475]  #1:  (debugfs_srcu){......}, at: [<ffffffff81320491>] debugfs_use_file_start+0x41/0xa0
[  309.661486]  #2:  (&attr->mutex){+.+.+.}, at: [<ffffffff8123a3e7>] simple_attr_write+0x37/0xe0
[  309.661495]  #3:  (&dev->struct_mutex){+.+.+.}, at: [<ffffffffa0091b4a>] i915_drop_caches_set+0x3a/0x150 [i915]
[  309.661540]
               the shortest dependencies between 2nd lock and 1st lock:
[  309.661547]  -> (cpu_hotplug.lock){+.+.+.} ops: 829 {
[  309.661553]     HARDIRQ-ON-W at:
[  309.661560]                       __lock_acquire+0x5e5/0x1b50
[  309.661565]                       lock_acquire+0xc9/0x220
[  309.661572]                       __mutex_lock+0x6e/0x990
[  309.661576]                       mutex_lock_nested+0x16/0x20
[  309.661583]                       get_online_cpus+0x61/0x80
[  309.661590]                       kmem_cache_create+0x25/0x1d0
[  309.661596]                       debug_objects_mem_init+0x30/0x249
[  309.661602]                       start_kernel+0x341/0x3fe
[  309.661607]                       x86_64_start_reservations+0x2a/0x2c
[  309.661612]                       x86_64_start_kernel+0x173/0x186
[  309.661619]                       verify_cpu+0x0/0xfc
[  309.661622]     SOFTIRQ-ON-W at:
[  309.661627]                       __lock_acquire+0x611/0x1b50
[  309.661632]                       lock_acquire+0xc9/0x220
[  309.661636]                       __mutex_lock+0x6e/0x990
[  309.661641]                       mutex_lock_nested+0x16/0x20
[  309.661646]                       get_online_cpus+0x61/0x80
[  309.661650]                       kmem_cache_create+0x25/0x1d0
[  309.661655]                       debug_objects_mem_init+0x30/0x249
[  309.661660]                       start_kernel+0x341/0x3fe
[  309.661664]                       x86_64_start_reservations+0x2a/0x2c
[  309.661669]                       x86_64_start_kernel+0x173/0x186
[  309.661674]                       verify_cpu+0x0/0xfc
[  309.661677]     RECLAIM_FS-ON-W at:
[  309.661682]                          mark_held_locks+0x6f/0xa0
[  309.661687]                          lockdep_trace_alloc+0xb3/0x100
[  309.661693]                          kmem_cache_alloc_trace+0x31/0x2e0
[  309.661699]                          __smpboot_create_thread.part.1+0x27/0xe0
[  309.661704]                          smpboot_create_threads+0x61/0x90
[  309.661709]                          cpuhp_invoke_callback+0x9c/0x8a0
[  309.661713]                          cpuhp_up_callbacks+0x31/0xb0
[  309.661718]                          _cpu_up+0x7a/0xc0
[  309.661723]                          do_cpu_up+0x5f/0x80
[  309.661727]                          cpu_up+0xe/0x10
[  309.661734]                          smp_init+0x71/0xb3
[  309.661738]                          kernel_init_freeable+0x94/0x19e
[  309.661743]                          kernel_init+0x9/0xf0
[  309.661748]                          ret_from_fork+0x2e/0x40
[  309.661752]     INITIAL USE at:
[  309.661757]                      __lock_acquire+0x234/0x1b50
[  309.661761]                      lock_acquire+0xc9/0x220
[  309.661766]                      __mutex_lock+0x6e/0x990
[  309.661771]                      mutex_lock_nested+0x16/0x20
[  309.661775]                      get_online_cpus+0x61/0x80
[  309.661780]                      __cpuhp_setup_state+0x44/0x170
[  309.661785]                      page_alloc_init+0x23/0x3a
[  309.661790]                      start_kernel+0x124/0x3fe
[  309.661794]                      x86_64_start_reservations+0x2a/0x2c
[  309.661799]                      x86_64_start_kernel+0x173/0x186
[  309.661804]                      verify_cpu+0x0/0xfc
[  309.661807]   }
[  309.661813]   ... key      at: [<ffffffff81e37690>] cpu_hotplug+0xb0/0x100
[  309.661817]   ... acquired at:
[  309.661821]    lock_acquire+0xc9/0x220
[  309.661825]    __mutex_lock+0x6e/0x990
[  309.661829]    mutex_lock_nested+0x16/0x20
[  309.661833]    get_online_cpus+0x61/0x80
[  309.661837]    _rcu_barrier+0x9f/0x160
[  309.661841]    rcu_barrier+0x10/0x20
[  309.661847]    netdev_run_todo+0x5f/0x310
[  309.661852]    rtnl_unlock+0x9/0x10
[  309.661856]    default_device_exit_batch+0x133/0x150
[  309.661862]    ops_exit_list.isra.0+0x4d/0x60
[  309.661866]    cleanup_net+0x1d8/0x2c0
[  309.661872]    process_one_work+0x1f4/0x6d0
[  309.661876]    worker_thread+0x49/0x4a0
[  309.661881]    kthread+0x107/0x140
[  309.661884]    ret_from_fork+0x2e/0x40

[  309.661890] -> (rcu_preempt_state.barrier_mutex){+.+.-.} ops: 179 {
[  309.661896]    HARDIRQ-ON-W at:
[  309.661901]                     __lock_acquire+0x5e5/0x1b50
[  309.661905]                     lock_acquire+0xc9/0x220
[  309.661910]                     __mutex_lock+0x6e/0x990
[  309.661914]                     mutex_lock_nested+0x16/0x20
[  309.661919]                     _rcu_barrier+0x31/0x160
[  309.661923]                     rcu_barrier+0x10/0x20
[  309.661928]                     netdev_run_todo+0x5f/0x310
[  309.661932]                     rtnl_unlock+0x9/0x10
[  309.661936]                     default_device_exit_batch+0x133/0x150
[  309.661941]                     ops_exit_list.isra.0+0x4d/0x60
[  309.661946]                     cleanup_net+0x1d8/0x2c0
[  309.661951]                     process_one_work+0x1f4/0x6d0
[  309.661955]                     worker_thread+0x49/0x4a0
[  309.661960]                     kthread+0x107/0x140
[  309.661964]                     ret_from_fork+0x2e/0x40
[  309.661968]    SOFTIRQ-ON-W at:
[  309.661972]                     __lock_acquire+0x611/0x1b50
[  309.661977]                     lock_acquire+0xc9/0x220
[  309.661981]                     __mutex_lock+0x6e/0x990
[  309.661986]                     mutex_lock_nested+0x16/0x20
[  309.661990]                     _rcu_barrier+0x31/0x160
[  309.661995]                     rcu_barrier+0x10/0x20
[  309.661999]                     netdev_run_todo+0x5f/0x310
[  309.662003]                     rtnl_unlock+0x9/0x10
[  309.662008]                     default_device_exit_batch+0x133/0x150
[  309.662013]                     ops_exit_list.isra.0+0x4d/0x60
[  309.662017]                     cleanup_net+0x1d8/0x2c0
[  309.662022]                     process_one_work+0x1f4/0x6d0
[  309.662027]                     worker_thread+0x49/0x4a0
[  309.662031]                     kthread+0x107/0x140
[  309.662035]                     ret_from_fork+0x2e/0x40
[  309.662039]    IN-RECLAIM_FS-W at:
[  309.662043]                        __lock_acquire+0x638/0x1b50
[  309.662048]                        lock_acquire+0xc9/0x220
[  309.662053]                        __mutex_lock+0x6e/0x990
[  309.662058]                        mutex_lock_nested+0x16/0x20
[  309.662062]                        _rcu_barrier+0x31/0x160
[  309.662067]                        rcu_barrier+0x10/0x20
[  309.662089]                        i915_gem_shrink_all+0x33/0x40 [i915]
[  309.662109]                        i915_drop_caches_set+0x141/0x150 [i915]
[  309.662114]                        simple_attr_write+0xc7/0xe0
[  309.662119]                        full_proxy_write+0x4f/0x70
[  309.662124]                        __vfs_write+0x23/0x120
[  309.662128]                        vfs_write+0xc6/0x1f0
[  309.662133]                        SyS_write+0x44/0xb0
[  309.662138]                        entry_SYSCALL_64_fastpath+0x1c/0xb1
[  309.662142]    INITIAL USE at:
[  309.662147]                    __lock_acquire+0x234/0x1b50
[  309.662151]                    lock_acquire+0xc9/0x220
[  309.662156]                    __mutex_lock+0x6e/0x990
[  309.662160]                    mutex_lock_nested+0x16/0x20
[  309.662165]                    _rcu_barrier+0x31/0x160
[  309.662169]                    rcu_barrier+0x10/0x20
[  309.662174]                    netdev_run_todo+0x5f/0x310
[  309.662178]                    rtnl_unlock+0x9/0x10
[  309.662183]                    default_device_exit_batch+0x133/0x150
[  309.662188]                    ops_exit_list.isra.0+0x4d/0x60
[  309.662192]                    cleanup_net+0x1d8/0x2c0
[  309.662197]                    process_one_work+0x1f4/0x6d0
[  309.662202]                    worker_thread+0x49/0x4a0
[  309.662206]                    kthread+0x107/0x140
[  309.662210]                    ret_from_fork+0x2e/0x40
[  309.662214]  }
[  309.662220]  ... key      at: [<ffffffff81e4e1c8>] rcu_preempt_state+0x508/0x780
[  309.662225]  ... acquired at:
[  309.662229]    check_usage_forwards+0x12b/0x130
[  309.662233]    mark_lock+0x360/0x6f0
[  309.662237]    __lock_acquire+0x638/0x1b50
[  309.662241]    lock_acquire+0xc9/0x220
[  309.662245]    __mutex_lock+0x6e/0x990
[  309.662249]    mutex_lock_nested+0x16/0x20
[  309.662253]    _rcu_barrier+0x31/0x160
[  309.662257]    rcu_barrier+0x10/0x20
[  309.662279]    i915_gem_shrink_all+0x33/0x40 [i915]
[  309.662298]    i915_drop_caches_set+0x141/0x150 [i915]
[  309.662303]    simple_attr_write+0xc7/0xe0
[  309.662307]    full_proxy_write+0x4f/0x70
[  309.662311]    __vfs_write+0x23/0x120
[  309.662315]    vfs_write+0xc6/0x1f0
[  309.662319]    SyS_write+0x44/0xb0
[  309.662323]    entry_SYSCALL_64_fastpath+0x1c/0xb1

[  309.662329]
               stack backtrace:
[  309.662335] CPU: 1 PID: 6435 Comm: gem_exec_gttfil Tainted: G        W       4.11.0-rc1-CI-CI_DRM_2333+ #1
[  309.662342] Hardware name: Hewlett-Packard HP Compaq 8100 Elite SFF PC/304Ah, BIOS 786H1 v01.13 07/14/2011
[  309.662348] Call Trace:
[  309.662354]  dump_stack+0x67/0x92
[  309.662359]  print_irq_inversion_bug.part.19+0x1a4/0x1b0
[  309.662365]  check_usage_forwards+0x12b/0x130
[  309.662369]  mark_lock+0x360/0x6f0
[  309.662374]  ? print_shortest_lock_dependencies+0x1a0/0x1a0
[  309.662379]  __lock_acquire+0x638/0x1b50
[  309.662383]  ? __mutex_unlock_slowpath+0x3e/0x2e0
[  309.662388]  ? trace_hardirqs_on+0xd/0x10
[  309.662392]  ? _rcu_barrier+0x31/0x160
[  309.662396]  lock_acquire+0xc9/0x220
[  309.662400]  ? _rcu_barrier+0x31/0x160
[  309.662404]  ? _rcu_barrier+0x31/0x160
[  309.662409]  __mutex_lock+0x6e/0x990
[  309.662412]  ? _rcu_barrier+0x31/0x160
[  309.662416]  ? _rcu_barrier+0x31/0x160
[  309.662421]  ? synchronize_rcu_expedited+0x35/0xb0
[  309.662426]  ? _raw_spin_unlock_irqrestore+0x52/0x60
[  309.662434]  mutex_lock_nested+0x16/0x20
[  309.662438]  _rcu_barrier+0x31/0x160
[  309.662442]  rcu_barrier+0x10/0x20
[  309.662464]  i915_gem_shrink_all+0x33/0x40 [i915]
[  309.662484]  i915_drop_caches_set+0x141/0x150 [i915]
[  309.662489]  simple_attr_write+0xc7/0xe0
[  309.662494]  full_proxy_write+0x4f/0x70
[  309.662498]  __vfs_write+0x23/0x120
[  309.662503]  ? rcu_read_lock_sched_held+0x75/0x80
[  309.662507]  ? rcu_sync_lockdep_assert+0x2a/0x50
[  309.662512]  ? __sb_start_write+0x102/0x210
[  309.662516]  ? vfs_write+0x17d/0x1f0
[  309.662520]  vfs_write+0xc6/0x1f0
[  309.662524]  ? trace_hardirqs_on_caller+0xe7/0x200
[  309.662529]  SyS_write+0x44/0xb0
[  309.662533]  entry_SYSCALL_64_fastpath+0x1c/0xb1
[  309.662537] RIP: 0033:0x7f507eac24a0
[  309.662541] RSP: 002b:00007fffda8720e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[  309.662548] RAX: ffffffffffffffda RBX: ffffffff81482bd3 RCX: 00007f507eac24a0
[  309.662552] RDX: 0000000000000005 RSI: 00007fffda8720f0 RDI: 0000000000000005
[  309.662557] RBP: ffffc9000048bf88 R08: 0000000000000000 R09: 000000000000002c
[  309.662561] R10: 0000000000000014 R11: 0000000000000246 R12: 00007fffda872230
[  309.662566] R13: 00007fffda872228 R14: 0000000000000201 R15: 00007fffda8720f0
[  309.662572]  ? __this_cpu_preempt_check+0x13/0x20

Fixes: 0eafec6d ("drm/i915: Enable lockless lookup of request tracking via RCU")
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=100192Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: <stable@vger.kernel.org> # v4.9+
Link: http://patchwork.freedesktop.org/patch/msgid/20170314115019.18127-1-chris@chris-wilson.co.ukReviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

The 33rd entry in the pre-CSC gamma table in Geminilake can represent a
value of 1.0 as 17 bits fixed point with one integer bit. However, the
table was generated such that the value of 1.0 would be 0.ffff with
all the intervals scaled accordingly. For instance, 0.5 mapped to
0.7fff instead of 0.8000.

For a reason that is not clear to the author, the rounding seems to be
different when a cursor plane is used, leading to some seemingly random
failures of the kms_cursor_crc igt tests. The differences weren't
perceptible at 8bpc with images captured by a Chamelium device, but did
cause CRC mismatches.
Signed-off-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170310101835.29845-1-ander.conselvan.de.oliveira@intel.com

There's really not a reason afaics that we can't just clean up
everything at the end, in the terminal postclose hook: Since this is
closing a file descriptor we know no one else can have a reference or
a thread doing something with that drm_file except the close code.
Ordering shouldn't matter, as long as we don't kfree before we clean
stuff up.

In the past this was more relevant when drivers still had to track and
clean up pending drm events, but that's all done by the core now.
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Liviu Dudau <Liviu.Dudau@arm.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170308141257.12119-13-daniel.vetter@ffwll.ch

This reverts commit bb10d4ec.

Since commit c8ebfad7 ("drm/i915: Ignore OpRegion panel type except
on select machines") we ignore the OpRegion panel type except for
specific machines (handled via a DMI match), so having SKL explicitly
excluded from using the OpRegion panel type is redundant. So let's
remove the SKL check.

Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170308143334.21216-1-ville.syrjala@linux.intel.comReviewed-by: Jani Nikula <jani.nikula@intel.com>

The trouble we have is that we can't really test all the shrinker
recursion stuff exhaustively in BAT because any kind of thrashing
stress test just takes too long.

But that leaves a really big gap open, since shrinker recursions are
one of the most annoying bugs. Now lockdep already has support for
checking allocation deadlocks:

- Direct reclaim paths are marked up with
  lockdep_set_current_reclaim_state() and
  lockdep_clear_current_reclaim_state().

- Any allocation paths are marked with lockdep_trace_alloc().

If we simply mark up our debugfs with the reclaim annotations, any
code and locks taken in there will automatically complete the picture
with any allocation paths we already have, as long as we have a simple
testcase in BAT which throws out a few objects using this interface.
Not stress test or thrashing needed at all.

v2: Need to EXPORT_SYMBOL_GPL to make it compile as a module.

v3: Fixup rebase fail (spotted by Chris).

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20170312205340.16202-1-daniel.vetter@ffwll.chSigned-off-by: Daniel Vetter <daniel.vetter@intel.com>

The main thing are the DDI ports. If there's a VBT that says there are
no outputs, we should trust that, and not have semi-random
defaults. Unfortunately, the defaults have resulted in some Chromebooks
without VBT to rely on this behaviour, so we split out the defaults for
the missing VBT case.
Reviewed-by: Manasi Navare <manasi.d.navare@intel.com>
Cc: Manasi Navare <manasi.d.navare@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/95c26079ff640d43f53b944f17e9fc356b36daec.1489152288.git.jani.nikula@intel.com

Use I915_{READ,WRITE}_FW() for updating the DSPARB registers on
VLV/CHV. This is less expesive as we can grab the uncore.lock across
the entire sequence of reads and writes instead of each register
access grabbing it.

This also allows us to eliminate the dsparb lock entirely as the
uncore.lock now effectively protects the contents of the DSPARB
registers.

v2: Add a note that interrupts are already disabled (Chris)

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170309154434.29303-6-ville.syrjala@linux.intel.comReviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

Optimize the plane register accesses a little bit by grabbing
the uncore lock manually across the entire pile of accesses and
using I915_READ_FW().

This helps keep the pipe update vblank evade critical section
below our 100 usec deadline, particularly with lockdep enabled.
And in general we want to keep that critical section as short
as possible as it's executed with interrupts disabled.

Not all plane updates currently happen from within the vblank evade
critical section, so we must use the irqsave/irqrestore variants
of the spinlock functions in the plane hooks.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170309154434.29303-5-ville.syrjala@linux.intel.comReviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

Pull all the plane register writes closer together to avoid having
a lot of unrelated stuff in between them. This will make things more
clear once we'll grab the uncore lock around the entire bunch. Also
in the future we might even consider moving more of the register
value computation out from the plane update hooks. This should make
that easier to do.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170309154434.29303-4-ville.syrjala@linux.intel.comReviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

Replace __raw_i915_read32() with I915_READ_FW() in the workaround for
the SKL+ scanline counter hardware fail. The two are the same thing
but everyone else uses I915_READ_FW() so let's follow suit.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170309154434.29303-3-ville.syrjala@linux.intel.comReviewed-by: Mika Kahola <mika.kahola@intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

Optimize the multi-register read in i915_get_vblank_counter() a little
bit by grabbing the uncore lock manually and using I915_READ_FW().
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170309154434.29303-2-ville.syrjala@linux.intel.comReviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

Check that the sink really declared 12bpc support before we enable it.
This should not actually never happen since it's mandatory for HDMI
sinks to support 12bpc if they support any deep color modes. But
reality disagrees with the theory and there are actually sinks in
the wild that violate the spec.

v2: Fix the output_types check
    Update commit message to state that these things are in fact real

Cc: stable@vger.kernel.org
Cc: Nicholas Sielicki <nicholas.sielicki@gmail.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=99250Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170213175818.24958-1-ville.syrjala@linux.intel.comReviewed-by: Shashank Sharma <shashank.sharma@intel.com>

i915_drpc_info missed covering a few register read with the runtime pm
wakelock. Be simple and cover the entire function with a single wakelock
so that new additions are not similarly missed in future.

  WARNING: CPU: 2 PID: 1334 at drivers/gpu/drm/i915/intel_drv.h:1743 gen6_read32+0x192/0x1e0 [i915]
  RPM wakelock ref not held during HW access
  Modules linked in: rpcsec_gss_krb5 nfsv4 dns_resolver netconsole nfsd auth_rpcgss ipmi_watchdog ipmi_poweroff ipmi_devintf ipmi_msghandler overlay btrfs xor raid6_pq dm_mod sg sd_mod snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic ata_generic pata_acpi intel_rapl x86_pkg_temp_thermal intel_powerclamp coretemp snd_hda_intel kvm_intel snd_hda_codec kvm eeepc_wmi irqbypass snd_hda_core crct10dif_pclmul crc32_pclmul crc32c_intel asus_wmi sparse_keymap ghash_clmulni_intel snd_hwdep i915 rfkill ppdev pcbc aesni_intel ata_piix crypto_simd glue_helper snd_pcm pata_via cryptd pcspkr snd_timer drm_kms_helper syscopyarea snd sysfillrect libata sysimgblt fb_sys_fops soundcore shpchp drm wmi parport_pc parport tpm_infineon video
  CPU: 2 PID: 1334 Comm: php5 Not tainted 4.10.0-rc8-01615-g1f58c8e7 #1
  Hardware name: System manufacturer System Product Name/P8H67-M PRO, BIOS 1002 04/01/2011
  Call Trace:
   dump_stack+0x63/0x8a
   __warn+0xcb/0xf0
   warn_slowpath_fmt+0x4f/0x60
   ? seq_vprintf+0x35/0x50
   gen6_read32+0x192/0x1e0 [i915]
   i915_drpc_info+0x55d/0x990 [i915]
   seq_read+0xf2/0x3b0
   full_proxy_read+0x51/0x80
   __vfs_read+0x28/0x130
   ? security_file_permission+0x9b/0xc0
   ? rw_verify_area+0x4e/0xb0
   vfs_read+0xa8/0x170
   SyS_read+0x46/0xa0
   entry_SYSCALL_64_fastpath+0x1a/0xa9
  RIP: 0033:0x7fd97bf175a0
  RSP: 002b:00007ffdf730db68 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
  RAX: ffffffffffffffda RBX: 00007fd978028738 RCX: 00007fd97bf175a0
  RDX: 0000000000002000 RSI: 00007fd97740e0d8 RDI: 0000000000000005
  RBP: 0000000000000001 R08: 0000000000e97840 R09: 00007fd977ef8d58
  R10: 0000000000000027 R11: 0000000000000246 R12: 00007fd977ef8d58
  R13: 0000000000000000 R14: 0000000000eb4640 R15: 0000000000000000
Reported-by: kernel test robot <xiaolong.ye@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170313095617.29010-1-chris@chris-wilson.co.ukReviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>

gen6_sanitize_rps_pm_mask() is small enough that inlining it shrinks the
object code.

v2: Use const markup
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170312135426.2216-1-chris@chris-wilson.co.ukReviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>

The patch 791ff39a: "drm/i915: Live testing for context
execution" from Feb 13, 2017, leads to the following static checker
warning:

        drivers/gpu/drm/i915/selftests/i915_gem_context.c:347 igt_ctx_exec()
        error: 'file' dereferencing possible ERR_PTR()
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: 791ff39a ("drm/i915: Live testing for context execution")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: <drm-intel-fixes@lists.freedesktop.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20170313124724.10614-1-chris@chris-wilson.co.ukReviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

The patch 6e32ab3d: "drm/i915: Fill different pages of the GTT"
from Feb 13, 2017, leads to the following static checker warning:

        drivers/gpu/drm/i915/selftests/i915_gem_gtt.c:583 walk_hole()
        error: 'vma' dereferencing possible ERR_PTR()
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: 6e32ab3d ("drm/i915: Fill different pages of the GTT"
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: <drm-intel-fixes@lists.freedesktop.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20170313100750.2685-1-chris@chris-wilson.co.ukReviewed-by: Matthew Auld <matthew.auld@intel.com>

If the object is coherent, we can simply update the cache domain on the
whole object rather than calculate the before/after clflushes. The
advantage is that we then get correct tracking of ellided flushes when
changing coherency later.

Testcase: igt/gem_pwrite_snooped
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170310000942.11661-1-chris@chris-wilson.co.ukReviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

The REDIRECT_TO_GUC bit is a strange beast as it is a disable bit -
setting the bit in the pm interrupt generation stops the interrupt going
to the guc (not sending it to the guc as the name implies). To help the
reader rename it to DISABLE_REDIRECT_TO_GUC so that we keep the bspec
greppable name without it being as confusing!
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Oscar Mateo <oscar.mateo@intel.com>
Cc: Radoslaw Szwichtenberg <radoslaw.szwichtenberg@intel.com>
Cc: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170312132745.9618-1-chris@chris-wilson.co.ukReviewed-by: Sagar Arun Kamble <sagar.a.kamble@intel.com>

Calculating the max pixel rate requires the new state, so use it there.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1489071125-917-6-git-send-email-maarten.lankhorst@linux.intel.comReviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Add a big fat warning in __intel_display_resume that the old state is
invalid, and use the correct state everywhere.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1489071125-917-5-git-send-email-maarten.lankhorst@linux.intel.comReviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
[mlankhorst: Change one occurence of conn_state to new_conn_state in
             verify_connector_state, and drop old_conn_state there]

The watermark code needs to look at the new allocations, so use
for_each_new_crtc_in_state everywhere.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1489071125-917-4-git-send-email-maarten.lankhorst@linux.intel.comReviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Use for_each_new_plane_in_state, only the new state is needed.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1489071125-917-3-git-send-email-maarten.lankhorst@linux.intel.comReviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>