This should be impossible, but let's assert that we do not pin a context
4 billion times before retiring!

v2: Fix the assertion -- the patch had just one job to do!
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170316171628.3228-1-chris@chris-wilson.co.ukReviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>

Provide some serialisation between user operations by waiting for the
reset initiated by setting i915_wedged to complete.

The automatic wait here makes
        echo 1 > i915_wedged; cat i915_error_state
do the right thing, and not risk reporting "No error collected".
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170316171305.12972-4-chris@chris-wilson.co.uk

When we wedge the device, we override engine->submit_request with a nop
to ensure that all in-flight requests are marked in error. However, igt
would like to unwedge the device to test -EIO handling. This requires us
to flush those in-flight requests and restore the original
engine->submit_request.

v2: Use a vfunc to unify enabling request submission to engines
v3: Split new vfunc to a separate patch.
v4: Make the wait interruptible -- the third party fences we wait upon
may be indefinitely broken, so allow the reset to be aborted.

Fixes: 821ed7df ("drm/i915: Update reset path to fix incomplete requests")
Testcase: igt/gem_eio
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> #v3
Link: http://patchwork.freedesktop.org/patch/msgid/20170316171305.12972-3-chris@chris-wilson.co.uk

It turns out that we may want to restore the original
engine->submit_request (and engine->schedule) callbacks from more than
just the guc <-> execlists transition. Move this to a vfunc so we can
have a common interface.

v2: Move initial selection to intel_engines_init_common(), repaint vfunc
with engine->set_default_submission (and a similar colour for the
helper).
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170316171305.12972-2-chris@chris-wilson.co.uk

I915_RESET_IN_PROGRESS is being used for both signaling the requirement
to i915_mutex_lock_interruptible() to avoid taking the struct_mutex and
to instruct a waiter (already holding the struct_mutex) to perform the
reset. To allow for a little more coordination, split these two meaning
into a couple of distinct flags. I915_RESET_BACKOFF tells
i915_mutex_lock_interruptible() not to acquire the mutex and
I915_RESET_HANDOFF tells the waiter to call i915_reset().
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Acked-by: NMichel Thierry <michel.thierry@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170316171305.12972-1-chris@chris-wilson.co.uk

GVTg has introduced the context status notifier to schedule the GVTg
workload. At that time, the notifier is bound to GVTg context only,
so GVTg is not aware of host workloads.

Now we are going to improve GVTg's guest workload scheduler policy,
and add Guc emulation support for new Gen graphics. Both these two
features require acknowledgment for all contexts running on hardware.
(But will not alter host workload.) So here try to make some change.

The change is simple:
  1. Move the context status notifier head from i915_gem_context to
     intel_engine_cs. Which means there is a notifier head per engine
     instead of per context. Execlist driver still call notifier for
     each context sched-in/out events of current engine.
  2. At GVTg side, it binds a notifier_block for each physical engine
     at GVTg initialization period. Then GVTg can hear all context
     status events.

In this patch, GVTg do nothing for host context event, but later
will add a function there. But in any case, the notifier callback is
a noop if this is no active vGPU.

Since intel_gvt_init() is called at early initialization stage and
require the status notifier head has been initiated, I initiate it in
intel_engine_setup().

v2: remove a redundant newline. (chris)

Fixes: 3c7ba635 ("drm/i915: Introduce execlist context status change notification")
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=100232Signed-off-by: NChangbin Du <changbin.du@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Zhi Wang <zhi.a.wang@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170313024711.28591-1-changbin.du@intel.comAcked-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

This emulates execlists on top of the GuC in order to defer submission of
requests to the hardware. This deferral allows time for high priority
requests to gazump their way to the head of the queue, however it nerfs
the GuC by converting it back into a simple execlist (where the CPU has
to wake up after every request to feed new commands into the GuC).

v2: Drop hack status - though iirc there is still a lockdep inversion
between fence and engine->timeline->lock (which is impossible as the
nesting only occurs on different fences - hopefully just requires some
judicious lockdep annotation)
v3: Apply lockdep nesting to enabling signaling on the request, using
the pattern we already have in __i915_gem_request_submit();
v4: Replaying requests after a hang also now needs the timeline
spinlock, to disable the interrupts at least
v5: Hold wq lock for completeness, and emit a tracepoint for enabling signal
v6: Reorder interrupt checking for a happier gcc.
v7: Only signal the tasklet after a user-interrupt if using guc scheduling
v8: Restore lost update of rq through the i915_guc_irq_handler (Tvrtko)
v9: Avoid re-initialising the engine->irq_tasklet from inside a reset
v10: Hook up the execlists-style tracepoints
v11: Clear the execlists irq_posted bit after taking over the interrupt/tasklet
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170316125619.6856-1-chris@chris-wilson.co.ukReviewed-by: NMichał Winiarski <michal.winiarski@intel.com>

When manually overwriting the HWS, rather than assume irq_seqno_barrier
does the right thing, we can explicitly flush the cacheline instead.
This avoids us calling the engine->irq_seqno_barrier() from an illegal
context:

[ 1472.651797] BUG: scheduling while atomic: migration/0/11/0x00000002
[ 1472.651807] Modules linked in: ctr ccm arc4 snd_hda_codec_hdmi bnep rfcomm iwldvm snd_hda_codec_conexant snd_hda_codec_generic snd_hda_intel mac80211 snd_hda_codec snd_hda_core snd_pcm dm_multipath snd_hwdep intel_powerclamp coretemp snd_seq_midi crct10dif_pclmul snd_seq_midi_event crc32_pclmul iwlwifi ghash_clmulni_intel btusb snd_rawmidi btrtl aesni_intel btbcm aes_x86_64 crypto_simd btintel cryptd glue_helper bluetooth snd_seq cfg80211 snd_timer snd_seq_device intel_ips binfmt_misc snd mei_me soundcore mei dm_mirror dm_region_hash dm_log i915 intel_gtt i2c_algo_bit drm_kms_helper cfbfillrect syscopyarea cfbimgblt sysfillrect sysimgblt fb_sys_fops cfbcopyarea prime_numbers e1000e drm ahci libahci
[ 1472.651897] CPU: 0 PID: 11 Comm: migration/0 Tainted: G     U          4.11.0-rc1+ #203
[ 1472.651899] Hardware name: LENOVO 514328U/514328U, BIOS 6QET44WW (1.14 ) 04/20/2010
[ 1472.651900] Call Trace:
[ 1472.651913]  dump_stack+0x63/0x90
[ 1472.651922]  __schedule_bug+0x5d/0x6b
[ 1472.651930]  __schedule+0x46a/0x5f0
[ 1472.651934]  schedule+0x38/0x90
[ 1472.651938]  schedule_hrtimeout_range_clock+0x85/0x110
[ 1472.651945]  ? hrtimer_init+0x10/0x10
[ 1472.651949]  schedule_hrtimeout_range+0xe/0x10
[ 1472.651952]  usleep_range+0x4d/0x60
[ 1472.652037]  gen5_seqno_barrier+0x13/0x20 [i915]
[ 1472.652101]  intel_engine_init_global_seqno+0xd7/0x160 [i915]
[ 1472.652160]  __i915_gem_set_wedged_BKL+0xa0/0x180 [i915]
[ 1472.652166]  multi_cpu_stop+0xbb/0xe0
[ 1472.652170]  ? cpu_stop_queue_work+0x90/0x90
[ 1472.652174]  cpu_stopper_thread+0x82/0x110
[ 1472.652179]  smpboot_thread_fn+0x137/0x190
[ 1472.652184]  kthread+0xf7/0x130
[ 1472.652187]  ? sort_range+0x20/0x20
[ 1472.652191]  ? kthread_park+0x90/0x90
[ 1472.652195]  ret_from_fork+0x2c/0x40

Testcase: igt/gem_eio #ilk
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170314111452.9375-1-chris@chris-wilson.co.ukReviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>

Set byt rc residency counters high level as chv does by
default. We lose some accuracy on byt but we can do the calculation
without extra hw read on both platforms, as now they behave
identically in this respect.

v2: use ktime
v3: keep comparison u32 (Chris)

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1489592584-10422-1-git-send-email-mika.kuoppala@intel.com

We have used cz timestamp register to gain a reference time wrt
to residency calculations. The residency counts are in cz clk ticks
(333Mhz clock) but for some reason the cz timestamp register gives
100us units. Perhaps for some other usage, the base-ten based values
are easier, but in residency calculations raw units would have been
the easiest.

As there is not much advantage of using base-ten clock through
a more costly punit access, take our reference times directly from
kernel clock.

v2: use ktime (Chris, Ville)

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Use intel_rc6_residency to get benefit for increased resolution
in byt/chv.

v2: output raw and time (Chris)
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Vlv and chv residency counters are 40 bits in width.
With a control bit, we can choose between upper or lower
32 bit window into this counter.

Lets toggle this bit on and off on and read both parts.
As a result we can push the wrap from 13 seconds to 54
minutes.

v2: commit msg, loop readability, goto elimination (Chris)
v3: bug ref, divide outside runtime pm lock (Chris)

References: https://bugs.freedesktop.org/show_bug.cgi?id=94852Reported-by: NLen Brown <len.brown@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Change the granularity from milliseconds to microseconds
when returning rc6 residencies. This is in preparation
for increased resolution on some platforms.

v2: use 64bit div macro (Chris)

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Plan is to make generic residency calculation utility
function for usage outside of sysfs. As a first step
move residency calculation into intel_pm.c
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

lockdep doesn't like us taking the mm->mmap_sem inside the get_pages
callback for a couple of reasons. The straightforward deadlock:

[13755.434059] =============================================
[13755.434061] [ INFO: possible recursive locking detected ]
[13755.434064] 4.11.0-rc1-CI-CI_DRM_297+ #1 Tainted: G     U
[13755.434066] ---------------------------------------------
[13755.434068] gem_userptr_bli/8398 is trying to acquire lock:
[13755.434070]  (&mm->mmap_sem){++++++}, at: [<ffffffffa00c988a>] i915_gem_userptr_get_pages+0x5a/0x2e0 [i915]
[13755.434096]
               but task is already holding lock:
[13755.434098]  (&mm->mmap_sem){++++++}, at: [<ffffffff8104d485>] __do_page_fault+0x105/0x560
[13755.434105]
               other info that might help us debug this:
[13755.434108]  Possible unsafe locking scenario:

[13755.434110]        CPU0
[13755.434111]        ----
[13755.434112]   lock(&mm->mmap_sem);
[13755.434115]   lock(&mm->mmap_sem);
[13755.434117]
                *** DEADLOCK ***

[13755.434121]  May be due to missing lock nesting notation

[13755.434126] 2 locks held by gem_userptr_bli/8398:
[13755.434128]  #0:  (&mm->mmap_sem){++++++}, at: [<ffffffff8104d485>] __do_page_fault+0x105/0x560
[13755.434135]  #1:  (&obj->mm.lock){+.+.+.}, at: [<ffffffffa00b887d>] __i915_gem_object_get_pages+0x1d/0x70 [i915]
[13755.434156]
               stack backtrace:
[13755.434161] CPU: 3 PID: 8398 Comm: gem_userptr_bli Tainted: G     U          4.11.0-rc1-CI-CI_DRM_297+ #1
[13755.434165] Hardware name: GIGABYTE GB-BKi7(H)A-7500/MFLP7AP-00, BIOS F4 02/20/2017
[13755.434169] Call Trace:
[13755.434174]  dump_stack+0x67/0x92
[13755.434178]  __lock_acquire+0x133a/0x1b50
[13755.434182]  lock_acquire+0xc9/0x220
[13755.434200]  ? i915_gem_userptr_get_pages+0x5a/0x2e0 [i915]
[13755.434204]  down_read+0x42/0x70
[13755.434221]  ? i915_gem_userptr_get_pages+0x5a/0x2e0 [i915]
[13755.434238]  i915_gem_userptr_get_pages+0x5a/0x2e0 [i915]
[13755.434255]  ____i915_gem_object_get_pages+0x25/0x60 [i915]
[13755.434272]  __i915_gem_object_get_pages+0x59/0x70 [i915]
[13755.434288]  i915_gem_fault+0x397/0x6a0 [i915]
[13755.434304]  ? i915_gem_fault+0x1a1/0x6a0 [i915]
[13755.434308]  ? __lock_acquire+0x449/0x1b50
[13755.434311]  ? __lock_acquire+0x449/0x1b50
[13755.434315]  ? vm_mmap_pgoff+0xa9/0xd0
[13755.434318]  __do_fault+0x19/0x70
[13755.434321]  __handle_mm_fault+0x863/0xe50
[13755.434325]  handle_mm_fault+0x17f/0x370
[13755.434329]  ? handle_mm_fault+0x40/0x370
[13755.434332]  __do_page_fault+0x279/0x560
[13755.434336]  do_page_fault+0xc/0x10
[13755.434339]  page_fault+0x22/0x30
[13755.434342] RIP: 0033:0x7f5ab91b5880
[13755.434345] RSP: 002b:00007fff62922218 EFLAGS: 00010216
[13755.434348] RAX: 0000000000b74500 RBX: 00007f5ab7f81000 RCX: 0000000000000000
[13755.434352] RDX: 0000000000100000 RSI: 00007f5ab7f81000 RDI: 00007f5aba61c000
[13755.434355] RBP: 00007f5aba61c000 R08: 0000000000000007 R09: 0000000100000000
[13755.434359] R10: 000000000000037d R11: 00007f5ab91b5840 R12: 0000000000000001
[13755.434362] R13: 0000000000000005 R14: 0000000000000001 R15: 0000000000000000

and cyclic deadlocks:

[ 2566.458979] ======================================================
[ 2566.459054] [ INFO: possible circular locking dependency detected ]
[ 2566.459127] 4.11.0-rc1+ #26 Not tainted
[ 2566.459194] -------------------------------------------------------
[ 2566.459266] gem_streaming_w/759 is trying to acquire lock:
[ 2566.459334]  (&obj->mm.lock){+.+.+.}, at: [<ffffffffa034bc80>] i915_gem_object_pin_pages+0x0/0xc0 [i915]
[ 2566.459605]
[ 2566.459605] but task is already holding lock:
[ 2566.459699]  (&mm->mmap_sem){++++++}, at: [<ffffffff8106fd11>] __do_page_fault+0x121/0x500
[ 2566.459814]
[ 2566.459814] which lock already depends on the new lock.
[ 2566.459814]
[ 2566.459934]
[ 2566.459934] the existing dependency chain (in reverse order) is:
[ 2566.460030]
[ 2566.460030] -> #1 (&mm->mmap_sem){++++++}:
[ 2566.460139]        lock_acquire+0xfe/0x220
[ 2566.460214]        down_read+0x4e/0x90
[ 2566.460444]        i915_gem_userptr_get_pages+0x6e/0x340 [i915]
[ 2566.460669]        ____i915_gem_object_get_pages+0x8b/0xd0 [i915]
[ 2566.460900]        __i915_gem_object_get_pages+0x6a/0x80 [i915]
[ 2566.461132]        __i915_vma_do_pin+0x7fa/0x930 [i915]
[ 2566.461352]        eb_add_vma+0x67b/0x830 [i915]
[ 2566.461572]        eb_lookup_vmas+0xafe/0x1010 [i915]
[ 2566.461792]        i915_gem_do_execbuffer+0x715/0x2870 [i915]
[ 2566.462012]        i915_gem_execbuffer2+0x106/0x2b0 [i915]
[ 2566.462152]        drm_ioctl+0x36c/0x670 [drm]
[ 2566.462236]        do_vfs_ioctl+0x12c/0xa60
[ 2566.462317]        SyS_ioctl+0x41/0x70
[ 2566.462399]        entry_SYSCALL_64_fastpath+0x1c/0xb1
[ 2566.462477]
[ 2566.462477] -> #0 (&obj->mm.lock){+.+.+.}:
[ 2566.462587]        __lock_acquire+0x1602/0x1790
[ 2566.462661]        lock_acquire+0xfe/0x220
[ 2566.462893]        i915_gem_object_pin_pages+0x4c/0xc0 [i915]
[ 2566.463116]        i915_gem_fault+0x2c2/0x8c0 [i915]
[ 2566.463197]        __do_fault+0x42/0x130
[ 2566.463276]        __handle_mm_fault+0x92c/0x1280
[ 2566.463356]        handle_mm_fault+0x1e2/0x440
[ 2566.463443]        __do_page_fault+0x1c4/0x500
[ 2566.463529]        do_page_fault+0xc/0x10
[ 2566.463613]        page_fault+0x1f/0x30
[ 2566.463693]
[ 2566.463693] other info that might help us debug this:
[ 2566.463693]
[ 2566.463820]  Possible unsafe locking scenario:
[ 2566.463820]
[ 2566.463918]        CPU0                    CPU1
[ 2566.463988]        ----                    ----
[ 2566.464068]   lock(&mm->mmap_sem);
[ 2566.464143]                                lock(&obj->mm.lock);
[ 2566.464226]                                lock(&mm->mmap_sem);
[ 2566.464304]   lock(&obj->mm.lock);
[ 2566.464378]
[ 2566.464378]  *** DEADLOCK ***
[ 2566.464378]
[ 2566.464504] 1 lock held by gem_streaming_w/759:
[ 2566.464576]  #0:  (&mm->mmap_sem){++++++}, at: [<ffffffff8106fd11>] __do_page_fault+0x121/0x500
[ 2566.464699]
[ 2566.464699] stack backtrace:
[ 2566.464801] CPU: 0 PID: 759 Comm: gem_streaming_w Not tainted 4.11.0-rc1+ #26
[ 2566.464881] Hardware name: GIGABYTE GB-BXBT-1900/MZBAYAB-00, BIOS F8 03/02/2016
[ 2566.464983] Call Trace:
[ 2566.465061]  dump_stack+0x68/0x9f
[ 2566.465144]  print_circular_bug+0x20b/0x260
[ 2566.465234]  __lock_acquire+0x1602/0x1790
[ 2566.465323]  ? debug_check_no_locks_freed+0x1a0/0x1a0
[ 2566.465564]  ? i915_gem_object_wait+0x238/0x650 [i915]
[ 2566.465657]  ? debug_lockdep_rcu_enabled.part.4+0x1a/0x30
[ 2566.465749]  lock_acquire+0xfe/0x220
[ 2566.465985]  ? i915_sg_trim+0x1b0/0x1b0 [i915]
[ 2566.466223]  i915_gem_object_pin_pages+0x4c/0xc0 [i915]
[ 2566.466461]  ? i915_sg_trim+0x1b0/0x1b0 [i915]
[ 2566.466699]  i915_gem_fault+0x2c2/0x8c0 [i915]
[ 2566.466939]  ? i915_gem_pwrite_ioctl+0xce0/0xce0 [i915]
[ 2566.467030]  ? __lock_acquire+0x642/0x1790
[ 2566.467122]  ? __lock_acquire+0x642/0x1790
[ 2566.467209]  ? debug_lockdep_rcu_enabled+0x35/0x40
[ 2566.467299]  ? get_unmapped_area+0x1b4/0x1d0
[ 2566.467387]  __do_fault+0x42/0x130
[ 2566.467474]  __handle_mm_fault+0x92c/0x1280
[ 2566.467564]  ? __pmd_alloc+0x1e0/0x1e0
[ 2566.467651]  ? vm_mmap_pgoff+0x160/0x190
[ 2566.467740]  ? handle_mm_fault+0x111/0x440
[ 2566.467827]  handle_mm_fault+0x1e2/0x440
[ 2566.467914]  ? handle_mm_fault+0x5d/0x440
[ 2566.468002]  __do_page_fault+0x1c4/0x500
[ 2566.468090]  do_page_fault+0xc/0x10
[ 2566.468180]  page_fault+0x1f/0x30
[ 2566.468263] RIP: 0033:0x557895ced32a
[ 2566.468337] RSP: 002b:00007fffd6dd8a10 EFLAGS: 00010202
[ 2566.468419] RAX: 00007f659a4db000 RBX: 0000000000000003 RCX: 00007f659ad032da
[ 2566.468501] RDX: 0000000000000000 RSI: 0000000000100000 RDI: 0000000000000000
[ 2566.468586] RBP: 0000000000000007 R08: 0000000000000003 R09: 0000000100000000
[ 2566.468667] R10: 0000000000000001 R11: 0000000000000246 R12: 0000557895ceda60
[ 2566.468749] R13: 0000000000000001 R14: 00007fffd6dd8ac0 R15: 00007f659a4db000

By checking the status of the gup worker (serialized by the
obj->mm.lock) we can determine whether it is still active, has failed or
has succeeded. If the worker is still active (or failed), we know that
it cannot be bound and so we can skip taking struct_mutex (risking
potential recursion). As we check the worker status, we mark it to
discard any partial results, forcing us to restart on the next
get_pages.
Reported-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Fixes: 1c8782dd ("drm/i915/userptr: Disallow wrapping GTT into a userptr")
Testcase: igt/gem_userptr_blits/map-fixed-invalidate-gup
Testcase: igt/gem_userptr_blits/dmabuf-sync
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170315140150.19432-1-chris@chris-wilson.co.ukReviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

After negative guc fw selection we could leave guc
submission flag still turned on. Reorder some checks
to cover this case. While here, fix info message and
return early if there is no Guc.
Signed-off-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NArkadiusz Hiler <arkadiusz.hiler@intel.com>
[tursulin: fixup bad alignment]
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170315133741.150420-1-michal.wajdeczko@intel.com

This field is used to determine which kind of firmware the struct
describes (GuC/HuC) - the name does not reflect.

The enum used here have "type" in the name, so let's go with that.

Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Oscar Mateo <oscar.mateo@intel.com>
Signed-off-by: NArkadiusz Hiler <arkadiusz.hiler@intel.com>
Reviewed-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170315133415.15343-1-arkadiusz.hiler@intel.com

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: NChris 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: NTvrtko 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: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NTvrtko 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: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NTvrtko 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: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NTvrtko 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: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: NTvrtko 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: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NTvrtko 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: NAntonio Argenziano <antonio.argenziano@intel.com>
Signed-off-by: NChris 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: NMichel 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: NMichal 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: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170314133309.126432-1-michal.wajdeczko@intel.comSigned-off-by: NChris 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: NArkadiusz Hiler <arkadiusz.hiler@intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NJoonas 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: NArkadiusz Hiler <arkadiusz.hiler@intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NJoonas 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: NArkadiusz Hiler <arkadiusz.hiler@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NJoonas 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: NArkadiusz Hiler <arkadiusz.hiler@intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NJoonas 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: NArkadiusz Hiler <arkadiusz.hiler@intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NJoonas 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: NArkadiusz Hiler <arkadiusz.hiler@intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NJoonas 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: NArkadiusz Hiler <arkadiusz.hiler@intel.com>
Reviewed-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: NJoonas 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: NArkadiusz Hiler <arkadiusz.hiler@intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NJoonas 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: NArkadiusz Hiler <arkadiusz.hiler@intel.com>
Reviewed-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: NJoonas 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: NArkadiusz Hiler <arkadiusz.hiler@intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NJoonas 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: NChris 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: NDaniel 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: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: NVille 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: NSean Paul <seanpaul@chromium.org>
Reviewed-by: NLiviu Dudau <Liviu.Dudau@arm.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel 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: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170308143334.21216-1-ville.syrjala@linux.intel.comReviewed-by: NJani 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: NChris Wilson <chris@chris-wilson.co.uk>
Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20170312205340.16202-1-daniel.vetter@ffwll.chSigned-off-by: NDaniel Vetter <daniel.vetter@intel.com>