Due to the slight asynchronicity in handling the execlists interrupts
(i.e. we defer the work to a handler that may consume more than one
interrupt event), when the engine is idle we may still have an irq
tasklet queued (especially when it has been deferred to a ksoftirqd).
At the beginning of the tasklet, we assert that we do hold a device
wakeref for the access we are about to perform. This assumes that when
we idle and release the GT wakeref, all execlists work has been
completed (since the elsp tracking says the hw is idle). However, there
may still be a tasklet queued, so as we mark the engine idle, also
cancel any pending tasklet.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170627152510.28589-1-chris@chris-wilson.co.ukReviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

We do not want to carry on over missing constructors and don't
need a duplicated engine mask checking which is already done
in the setup phase.
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Coffee Lake inherit most of Kabylake production
workarounds.

v2: Fix typo on commit message and remove
    WaDisableKillLogic and GEN9_DISABLE_OCL_OOB_SUPPRESS_LOGIC,
    since as Mika pointed out they shouldn't be here for cfl
    according to BSpec.

Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1497653398-15722-1-git-send-email-rodrigo.vivi@intel.com

As another precaution when testing whether the CS engine is actually
idle, also inspect the ring's HEAD/TAIL registers, which should be equal
when there are no commands left to execute by the GPU.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170530121334.17364-3-chris@chris-wilson.co.ukReviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>

Allow intel_engine_is_idle() to be called outside of the GT wakeref by
acquiring the device runtime pm for ourselves. This allows the function
to act as check after we assume the engine is idle and we release the GT
wakeref held whilst we have requests. At the moment, we do not call it
outside of an awake context but taking the wakeref as required makes it
more convenient to use for quick debugging in future.

[ 2613.401647] RPM wakelock ref not held during HW access
[ 2613.401684] ------------[ cut here ]------------
[ 2613.401720] WARNING: CPU: 5 PID: 7739 at drivers/gpu/drm/i915/intel_drv.h:1787 gen6_read32+0x21f/0x2b0 [i915]
[ 2613.401731] Modules linked in: snd_hda_intel i915 vgem snd_hda_codec_hdmi x86_pkg_temp_thermal intel_powerclamp snd_hda_codec_realtek coretemp snd_hda_codec_generic crct10dif_pclmul crc32_pclmul ghash_clmulni_intel snd_hda_codec snd_hwdep snd_hda_core snd_pcm r8169 mii mei_me lpc_ich mei prime_numbers [last unloaded: i915]
[ 2613.401823] CPU: 5 PID: 7739 Comm: drv_missed_irq Tainted: G     U          4.12.0-rc2-CI-CI_DRM_421+ #1
[ 2613.401825] Hardware name: MSI MS-7924/Z97M-G43(MS-7924), BIOS V1.12 02/15/2016
[ 2613.401840] task: ffff880409e3a740 task.stack: ffffc900084dc000
[ 2613.401861] RIP: 0010:gen6_read32+0x21f/0x2b0 [i915]
[ 2613.401863] RSP: 0018:ffffc900084dfce8 EFLAGS: 00010292
[ 2613.401869] RAX: 000000000000002a RBX: ffff8804016a8000 RCX: 0000000000000006
[ 2613.401871] RDX: 0000000000000006 RSI: ffffffff81cbf2d9 RDI: ffffffff81c9e3a7
[ 2613.401874] RBP: ffffc900084dfd18 R08: ffff880409e3afc8 R09: 0000000000000000
[ 2613.401877] R10: 000000008a1c483f R11: 0000000000000000 R12: 000000000000209c
[ 2613.401879] R13: 0000000000000001 R14: ffff8804016a8000 R15: ffff8804016ac150
[ 2613.401882] FS:  00007f39ef3dd8c0(0000) GS:ffff88041fb40000(0000) knlGS:0000000000000000
[ 2613.401885] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 2613.401887] CR2: 00000000023717c8 CR3: 00000002e7b34000 CR4: 00000000001406e0
[ 2613.401889] Call Trace:
[ 2613.401912]  intel_engine_is_idle+0x76/0x90 [i915]
[ 2613.401931]  i915_gem_wait_for_idle+0xe6/0x1e0 [i915]
[ 2613.401951]  fault_irq_set+0x40/0x90 [i915]
[ 2613.401970]  i915_ring_test_irq_set+0x42/0x50 [i915]
[ 2613.401976]  simple_attr_write+0xc7/0xe0
[ 2613.401981]  full_proxy_write+0x4f/0x70
[ 2613.401987]  __vfs_write+0x23/0x120
[ 2613.401992]  ? rcu_read_lock_sched_held+0x75/0x80
[ 2613.401996]  ? rcu_sync_lockdep_assert+0x2a/0x50
[ 2613.401999]  ? __sb_start_write+0xfa/0x1f0
[ 2613.402004]  vfs_write+0xc5/0x1d0
[ 2613.402008]  ? trace_hardirqs_on_caller+0xe7/0x1c0
[ 2613.402013]  SyS_write+0x44/0xb0
[ 2613.402020]  entry_SYSCALL_64_fastpath+0x1c/0xb1
[ 2613.402022] RIP: 0033:0x7f39eded6670
[ 2613.402025] RSP: 002b:00007fffdcdcb1a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[ 2613.402030] RAX: ffffffffffffffda RBX: ffffffff81470203 RCX: 00007f39eded6670
[ 2613.402033] RDX: 0000000000000001 RSI: 000000000041bc33 RDI: 0000000000000006
[ 2613.402036] RBP: ffffc900084dff88 R08: 00007f39ef3dd8c0 R09: 0000000000000001
[ 2613.402038] R10: 0000000000000000 R11: 0000000000000246 R12: 000000000041bc33
[ 2613.402041] R13: 0000000000000006 R14: 0000000000000000 R15: 0000000000000000
[ 2613.402046]  ? __this_cpu_preempt_check+0x13/0x20
[ 2613.402052] Code: 01 9b fa e0 0f ff e9 28 fe ff ff 80 3d 6a dd 0e 00 00 0f 85 29 fe ff ff 48 c7 c7 48 19 29 a0 c6 05 56 dd 0e 00 01 e8 da 9a fa e0 <0f> ff e9 0f fe ff ff b9 01 00 00 00 ba 01 00 00 00 44 89 e6 48
[ 2613.402199] ---[ end trace 31f0cfa93ab632bf ]---

Fixes: 5400367a ("drm/i915: Ensure the engine is idle before manually changing HWS")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170530121334.17364-2-chris@chris-wilson.co.ukReviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

All the requests at the same priority are executed in FIFO order. They
do not need to be stored in the rbtree themselves, as they are a simple
list within a level. If we move the requests at one priority into a list,
we can then reduce the rbtree to the set of priorities. This should keep
the height of the rbtree small, as the number of active priorities can not
exceed the number of active requests and should be typically only a few.

Currently, we have ~2k possible different priority levels, that may
increase to allow even more fine grained selection. Allocating those in
advance seems a waste (and may be impossible), so we opt for allocating
upon first use, and freeing after its requests are depleted. To avoid
the possibility of an allocation failure causing us to lose a request,
we preallocate the default priority (0) and bump any request to that
priority if we fail to allocate it the appropriate plist. Having a
request (that is ready to run, so not leading to corruption) execute
out-of-order is better than leaking the request (and its dependency
tree) entirely.

There should be a benefit to reducing execlists_dequeue() to principally
using a simple list (and reducing the frequency of both rbtree iteration
and balancing on erase) but for typical workloads, request coalescing
should be small enough that we don't notice any change. The main gain is
from improving PI calls to schedule, and the explicit list within a
level should make request unwinding simpler (we just need to insert at
the head of the list rather than the tail and not have to make the
rbtree search more complicated).

v2: Avoid use-after-free when deleting a depleted priolist

v3: Michał found the solution to handling the allocation failure
gracefully. If we disable all priority scheduling following the
allocation failure, those requests will be executed in fifo and we will
ensure that this request and its dependencies are in strict fifo (even
when it doesn't realise it is only a single list). Normal scheduling is
restored once we know the device is idle, until the next failure!
Suggested-by: NMichał Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NMichał Winiarski <michal.winiarski@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170517121007.27224-8-chris@chris-wilson.co.uk

add/remove: 1/1 grow/shrink: 5/4 up/down: 391/-578 (-187)
function                                     old     new   delta
execlists_submit_ports                       262     471    +209
port_assign.isra                               -     136    +136
capture                                     6344    6359     +15
reset_common_ring                            438     452     +14
execlists_submit_request                     228     238     +10
gen8_init_common_ring                        334     341      +7
intel_engine_is_idle                         106     105      -1
i915_engine_info                            2314    2290     -24
__i915_gem_set_wedged_BKL                    485     411     -74
intel_lrc_irq_handler                       1789    1604    -185
execlists_update_context                     294       -    -294

The most important change there is the improve to the
intel_lrc_irq_handler and excclist_submit_ports (net improvement since
execlists_update_context is now inlined).

v2: Use the port_api() for guc as well (even though currently we do not
pack any counters in there, yet) and hide all port->request_count inside
the helpers.
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/20170517121007.27224-5-chris@chris-wilson.co.uk

This basically reverts commit 465418c6
("drm/i915/gen9: Remove WaEnableYV12BugFixInHalfSliceChicken7")
with small addition - marking it as affecting GLK as well.

It was incorrectly considered fixed in production steppings.

References: HSD#2126385, HSD#2131381, HSDES#1504433555, BSID#0764
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Jeff McGee <jeff.mcgee@intel.com>
Signed-off-by: NArkadiusz Hiler <arkadiusz.hiler@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
[Mika: s/KBL/GLK on commit message]
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170512112015.19082-1-arkadiusz.hiler@intel.com

Since unifying ringbuffer/execlist submission to use
engine->pin_context, we ensure that the intel_ring is available before
we start constructing the request. We can therefore move the assignment
of the request->ring to the central i915_gem_request_alloc() and not
require it in every engine->request_alloc() callback. Another small step
towards simplification (of the core, but at a cost of handling error
pointers in less important callers of engine->pin_context).

v2: Rearrange a few branches to reduce impact of PTR_ERR() on gcc's code
generation.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Oscar Mateo <oscar.mateo@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NOscar Mateo <oscar.mateo@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170504093308.4137-1-chris@chris-wilson.co.uk

Pre-calculate engine context size based on engine class and device
generation and store it in the engine instance.

v2:
- Squash and get rid of hw_context_size (Chris)

v3:
- Move after MMIO init for probing on Gen7 and 8 (Chris)
- Retained rounding (Tvrtko)
v4:
- Rebase for deferred legacy context allocation
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Oscar Mateo <oscar.mateo@intel.com>
Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: intel-gvt-dev@lists.freedesktop.org
Acked-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

The hangcheck runs independently to the main flow of seqno through the
driver. However, we have an odd coupling of the seqno reset that is
unwelcome, and if poked at just the right rate can cause spurious hangs
(e.g. gem_exec_whisper) on an apparently idle engine.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170421083113.21321-1-chris@chris-wilson.co.uk

If we have a mock engine and it has no more requests in flight, report
it as idle as there is no hardware to contradict us! Otherwise we
attempt to query the hw that doesn't exist and find that the hw hasn't
set its idle bit and we get upset.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170411234427.14841-2-chris@chris-wilson.co.ukReviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

Similar to commit 8490ae20 ("drm/i915: Suppress busy status for
engines if wedged") we also want to report intel_engine_is_idle() as
true as well as the main intel_engines_are_idle(), as we now check that
the engines are idle when overwriting the HWS page. This is not true
whilst we are setting the device as wedged, at least according to our
bookkeeping, so we have to lie to ourselves!

[  383.588601] [drm:i915_reset [i915]] *ERROR* Failed to reset chip: -110
[  383.588685] ------------[ cut here ]------------
[  383.588755] WARNING: CPU: 0 PID: 12 at drivers/gpu/drm/i915/intel_engine_cs.c:226 intel_engine_init_global_seqno+0x222/0x290 [i915]
[  383.588757] WARN_ON(!intel_engine_is_idle(engine))
[  383.588759] Modules linked in: ctr ccm snd_hda_codec_hdmi snd_hda_codec_conexant snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hda_core arc4 iwldvm mac80211 snd_pcm snd_hwdep snd_seq_midi snd_seq_midi_event rfcomm bnep snd_rawmidi intel_powerclamp coretemp dm_multipath iwlwifi crct10dif_pclmul snd_seq crc32_pclmul ghash_clmulni_intel btusb aesni_intel btrtl btbcm aes_x86_64 crypto_simd cryptd btintel snd_timer glue_helper bluetooth intel_ips snd_seq_device cfg80211 snd soundcore binfmt_misc mei_me 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 ahci libahci drm e1000e
[  383.588851] CPU: 0 PID: 12 Comm: migration/0 Not tainted 4.11.0-rc5+ #207
[  383.588853] Hardware name: LENOVO 514328U/514328U, BIOS 6QET44WW (1.14 ) 04/20/2010
[  383.588855] Call Trace:
[  383.588866]  dump_stack+0x63/0x90
[  383.588871]  __warn+0xc7/0xf0
[  383.588876]  warn_slowpath_fmt+0x4a/0x50
[  383.588883]  ? set_next_entity+0x821/0x910
[  383.588943]  intel_engine_init_global_seqno+0x222/0x290 [i915]
[  383.588998]  __i915_gem_set_wedged_BKL+0xa4/0x190 [i915]
[  383.589003]  ? __switch_to+0x215/0x390
[  383.589008]  multi_cpu_stop+0xbb/0xe0
[  383.589012]  ? cpu_stop_queue_work+0x90/0x90
[  383.589016]  cpu_stopper_thread+0x82/0x110
[  383.589021]  smpboot_thread_fn+0x137/0x190
[  383.589026]  kthread+0xf7/0x130
[  383.589030]  ? sort_range+0x20/0x20
[  383.589034]  ? kthread_park+0x90/0x90
[  383.589040]  ret_from_fork+0x2c/0x40

Fixes: 2ca9faa5 ("drm/i915: Assert the engine is idle before overwiting the HWS")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170411190042.25662-1-chris@chris-wilson.co.uk

In places, we assume that RCS exists. This has been true forever, but
let us catch this failure during bringup by adding an explicit check
that we do have an RCS engine.

v2: Make use of HAS_ENGINE (Tvrtko)
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170411165658.23828-1-chris@chris-wilson.co.uk

We want to refer to the index of the engine consistently throughout the
userspace ABI. We already have such an index through the execbuffer
engine specifier, that needs to be able to refer to each engine
specifically, so rename it the index to uabi_id to reflect its
generality beyond execbuf.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170411124306.15448-1-chris@chris-wilson.co.uk

There are some properties that logically belong to the engine class, and some
that belong to the engine instance. Make it explicit.

v2: Commit message (Tvrtko)

v3:
  - Rebased
  - Exec/uabi id should be per instance (Chris)

v4:
  - Rebased
  - Avoid re-ordering fields for smaller diff (Tvrtko)
  - Bug on oob access to the class array (Michal)

v5: Bug on the right thing (Michal)

v6: Rebased

Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1491834873-9345-5-git-send-email-oscar.mateo@intel.comReviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Not really needed, but makes the next change a little bit more compact.

v2:
  - Use zero-based numbering for engine names: xcs0, xcs1.. xcsN (Tvrtko, Chris)
  - Make sure the mock engine name is null-terminated (Tvrtko, Chris)

v3: Because I'm stupid (Chris)

v4: Verify engine name wasn't truncated (Michal)

v5:
  - Kill the warning in mock engine (Chris)

Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1491834873-9345-4-git-send-email-oscar.mateo@intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

If we needed to do something different for the init functions, we could
always look at the engine instance to make the distinction. But, in any
case, the two functions are virtually identical already (please notice
that BSD2_RING is only used from gen8 onwards).

With this, the init functions depends excusively on the engine class
(a fact that we will use soon).

v2: Commit message

Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1491834873-9345-3-git-send-email-oscar.mateo@intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

In such a way that vcs and vcs2 are just two different instances (0 and 1)
of the same engine class (VIDEO_DECODE_CLASS).

v2: Align the instance types (Tvrtko)

v3: Don't use enums for bspec-defined stuff (Michal)

Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1491834873-9345-2-git-send-email-oscar.mateo@intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

When we update the global seqno (on the engine timeline), we modify HW
state (both registers and mapped pages). As we do this, we should be
sure that the HW is idle and we are not causing a conflict. The caller
is supposed to wait_for_idle before calling us to update the seqno, so
let's assert they have and the engine is indeed idle.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170405153055.28123-1-chris@chris-wilson.co.ukReviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

If the driver is wedged, HW state may be very inconsistent and
report that it is still busy, even though we have stopped using it. This
can lead to a double *ERROR* rather than a graceful cleanup after
wedging.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170330145041.9005-2-chris@chris-wilson.co.uk

We pretty print the name of an engine in several places, mostly for
debug, but also in the GPU hang report. Using "ring" in the name is
archaic (we call those engines now to differentiate them from the
multiple rings of commands we execute on each engine), quite verbose and
often tautological. We run out of room in our GPU hang report for
instance if we have more than a couple of engines hung simultaneously.
Bit the bullet and update the strings to reflect the common internal names.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170330134820.12273-1-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>
(cherry picked from commit 3fc03069)
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170321144720.17020-1-chris@chris-wilson.co.uk

As intel_engine_init_global_seqno() may be called by
nop_submit_request() from inside irq context, we have to use atomic
versions of kmap/kunmap. This is rare as this requires using gen8 legacy
ringbuffer submission.
Reported-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170320145609.4898-1-chris@chris-wilson.co.ukReviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

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

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>

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>

Generally we are using macros for any hardware identifiers as these
may change between Gens. Do the same with hardware engine ids.

v2: move hw engine defs to i915_reg.h (Chris)
Signed-off-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170301202615.118632-1-michal.wajdeczko@intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

The code to check for execlists completion is generic, so move it to
intel_engine_cs.c, where we can reuse the new intel_engine_is_idle().
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170303121947.20482-2-chris@chris-wilson.co.ukReviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>

During reset_all_global_seqno() on seqno rollover, we have to update the
HWS. This causes all in flight requests to be completed, so first we
wait. However, we were only waiting for the requests themselves to be
completed and clearing out the waiter rbtrees - what I had missed was
the extra reference in execlists->port[]. Since commit fe9ae7a3
("drm/i915/execlists: Detect an out-of-order context switch") we can
detect when the request is retired before the context switch interrupt
is completed. The impact should be neglible outside of debugging.

Testcase: igt/gem_exec_whisper
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170303121947.20482-1-chris@chris-wilson.co.ukReviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>

The spam of every context initialisation saying the same thing is annoying
me! Move the information to the setup of the engine.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170301121131.11588-1-chris@chris-wilson.co.ukReviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

Replace the global device seqno with one for each engine, and account
for in-flight seqno on each separately. This is consistent with
dma-fence as each timeline has separate fence-contexts for each engine
and a seqno is only ordered within a fence-context (i.e.  seqno do not
need to be ordered wrt to other engines, just ordered within a single
engine). This is required to enable request rewinding for preemption on
individual engines (we have to rewind the global seqno to avoid
overflow, and we do not have to rewind all engines just to preempt one.)

v2: Rename active_seqno to inflight_seqnos to more clearly indicate that
it is a counter and not equivalent to the existing seqno. Update
functions that operated on active_seqno similarly.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170223074422.4125-3-chris@chris-wilson.co.uk

It is used by all submission backends.
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

We can call the engine cleanup vfunc instead of duplicating the
decision making here.
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

First retroactive test, make sure that the waiters are in global seqno
order after random inserts and removals.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170213171558.20942-3-chris@chris-wilson.co.uk

In order to reset the GPU early on in the module load sequence, we need
to allocate the basic engine structs (to populate the mmio offsets etc).
Currently, the engine initialisation allocates both the base struct and
also allocate auxiliary objects, which depend upon state setup quite
late in the load sequence. We split off the allocation callback for
later and allow ourselves to allocate the engine structs themselves
early.

v2: Different paint for the unwind following error.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170124110135.6418-1-chris@chris-wilson.co.uk

With the introduce of i915_vma_instance() for obtaining the VMA
singleton for a (obj, vm, view) tuple, we can remove the
i915_vma_create() in favour of a single entry point. We do incur a
lookup onto an empty tree, but the i915_vma_create() were being called
infrequently and during initialisation, so the small overhead is
negligible.

v2: Drop the i915_ prefix from the now static vma_create() function
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170116152131.18089-4-chris@chris-wilson.co.uk

The requests conversion introduced a nasty bug where we could generate a
new request in the middle of constructing a request if we needed to idle
the system in order to evict space for a context. The request to idle
would be executed (and waited upon) before the current one, creating a
minor havoc in the seqno accounting, as we will consider the current
request to already be completed (prior to deferred seqno assignment) but
ring->last_retired_head would have been updated and still could allow
us to overwrite the current request before execution.

We also employed two different mechanisms to track the active context
until it was switched out. The legacy method allowed for waiting upon an
active context (it could forcibly evict any vma, including context's),
but the execlists method took a step backwards by pinning the vma for
the entire active lifespan of the context (the only way to evict was to
idle the entire GPU, not individual contexts). However, to circumvent
the tricky issue of locking (i.e. we cannot take struct_mutex at the
time of i915_gem_request_submit(), where we would want to move the
previous context onto the active tracker and unpin it), we take the
execlists approach and keep the contexts pinned until retirement.
The benefit of the execlists approach, more important for execlists than
legacy, was the reduction in work in pinning the context for each
request - as the context was kept pinned until idle, it could short
circuit the pinning for all active contexts.

We introduce new engine vfuncs to pin and unpin the context
respectively. The context is pinned at the start of the request, and
only unpinned when the following request is retired (this ensures that
the context is idle and coherent in main memory before we unpin it). We
move the engine->last_context tracking into the retirement itself
(rather than during request submission) in order to allow the submission
to be reordered or unwound without undue difficultly.

And finally an ulterior motive for unifying context handling was to
prepare for mock requests.

v2: Rename to last_retired_context, split out legacy_context tracking
for MI_SET_CONTEXT.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161218153724.8439-3-chris@chris-wilson.co.uk

Like GEM init, GUC init, MOCS init and context creation.

Enables them to lose dev_priv locals.
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

Where it is more appropriate and also to be consistent with
the direction of the driver.

v2: Leave out object alloc/free inlining. (Joonas Lahtinen)
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>