Starting from Gen11 the context descriptor format has been updated in
the HW. The hw_id field has been considerably reduced in size and engine
class and instance fields have been added.

There is a slight name clashing issue because the field that we call
hw_id is actually called SW Context ID in the specs for Gen11+.

With the current size of the hw_id field we can have a maximum of 2k
contexts at any time, but we could use the sw_counter field (which is sw
defined) to increase that because the HW requirement is that
engine_id + sw id + sw_counter is a unique number.
GuC uses a similar method to support more contexts but does its tracking
at lrc level. To avoid doing an implementation that will need to be
reworked once GuC support lands, defer it for now and mark it as TODO.

v2: rebased, add documentation, fix GEN11_ENGINE_INSTANCE_SHIFT
v3: rebased, bring back lost code from i915_gem_context.c
v4: make TODO comment more generic
v5: be consistent with bit ordering, add extra checks (Chris)

Cc: Oscar Mateo <oscar.mateo@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Signed-off-by: NDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: NOscar Mateo <oscar.mateo@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180302161501.28594-3-mika.kuoppala@linux.intel.comSigned-off-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>

Gen11 has up to 4 VCS and up to 2 VECS engines, this patch adds mmio
base definitions for all of them.

Bspec: 20944
Bspec: 7021

v2: Set the correct mmio_base in intel_engines_init_mmio; updating the
base mmio values any later would cause incorrect reads in
i915_gem_sanitize (Michel).

Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Ceraolo Spurio, Daniele <daniele.ceraolospurio@intel.com>
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Signed-off-by: NMichel Thierry <michel.thierry@intel.com>
Reviewed-by: NDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180302161501.28594-2-mika.kuoppala@linux.intel.comSigned-off-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>

Although we protect the request itself, we don't lock inside
intel_engine_dump() and so the request maybe retired as we peek into it.
One consequence is that the request->ctx may be freed before we
dereference it, leading to a use-after-free. Replace the hw_id we are
peeking from inside request->ctx with the request->fence.context, with
which we can still track from which context the request originated
(although to tie to HW reports requires a little more legwork, but is
good enough to follow the GEM traces).

[52640.729670] general protection fault: 0000 [#2] SMP
[52640.729694] Dumping ftrace buffer:
[52640.729701]    (ftrace buffer empty)
[52640.729705] Modules linked in: vgem snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic x86_pkg_\
temp_thermal intel_powerclamp coretemp crct10dif_pclmul crc32_pclmul snd_hda_intel snd_hda_codec snd_hwdep gha\
sh_clmulni_intel snd_hda_core snd_pcm mei_me mei i915 r8169 mii prime_numbers i2c_hid
[52640.729748] CPU: 2 PID: 4335 Comm: gem_exec_schedu Tainted: G     UD W        4.16.0-rc3+ #7
[52640.729759] Hardware name: Acer Aspire E5-575G/Ironman_SK  , BIOS V1.12 08/02/2016
[52640.729803] RIP: 0010:print_request+0x2b/0xb0 [i915]
[52640.729811] RSP: 0018:ffffc90001453c18 EFLAGS: 00010206
[52640.729820] RAX: 6b6b6b6b6b6b6b6b RBX: ffff8801e0292d40 RCX: 0000000000000006
[52640.729829] RDX: ffffc90001453c60 RSI: ffff8801e0292d40 RDI: 0000000000000003
[52640.729838] RBP: ffffc90001453d80 R08: 0000000000000000 R09: 0000000000000001
[52640.729847] R10: ffffc90001453bd0 R11: ffffc90001453c73 R12: ffffc90001453c60
[52640.729856] R13: ffffc90001453d80 R14: ffff8801d5a683c8 R15: ffff8801e0292d40
[52640.729866] FS:  00007f1ee50548c0(0000) GS:ffff8801e8200000(0000) knlGS:0000000000000000
[52640.729876] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[52640.729884] CR2: 00007f1ee5077000 CR3: 00000001d9411004 CR4: 00000000003606e0
[52640.729893] Call Trace:
[52640.729922]  intel_engine_print_registers+0x623/0x890 [i915]
[52640.729948]  intel_engine_dump+0x4a3/0x590 [i915]
[52640.729957]  ? seq_printf+0x3a/0x50
[52640.729977]  i915_engine_info+0xb8/0xe0 [i915]
[52640.729984]  ? drm_mode_gamma_get_ioctl+0xf0/0xf0
[52640.729990]  seq_read+0xd5/0x410
[52640.729997]  full_proxy_read+0x4b/0x70
[52640.730004]  __vfs_read+0x1e/0x120
[52640.730009]  ? do_sys_open+0x134/0x220
[52640.730015]  ? kmem_cache_free+0x174/0x2b0
[52640.730021]  vfs_read+0xa1/0x150
[52640.730026]  SyS_read+0x40/0xa0
[52640.730032]  do_syscall_64+0x65/0x1a0
[52640.730038]  entry_SYSCALL_64_after_hwframe+0x42/0xb7
Reported-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180228094732.28462-1-chris@chris-wilson.co.uk

Sometimes we need to boost the priority of an in-flight request, which
may lead to the situation where the second submission port then contains
a higher priority context than the first and so we need to inject a
preemption event. To do so we must always check inside
execlists_dequeue() whether there is a priority inversion between the
ports themselves as well as the head of the priority sorted queue, and we
cannot just skip dequeuing if the queue is empty.

As Michał noted, this doesn't simply extend to handling more than 2-port
submission, as we may need to reorder within the array of executing
requests which themselves are lower priority than the first. A task for
later!
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Cc: Michel Thierry <michel.thierry@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180222142229.14517-1-chris@chris-wilson.co.ukReviewed-by: NMichał Winiarski <michal.winiarski@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>

We want to de-emphasize the link between the request (dependency,
execution and fence tracking) from GEM and so rename the struct from
drm_i915_gem_request to i915_request. That is we may implement the GEM
user interface on top of requests, but they are an abstraction for
tracking execution rather than an implementation detail of GEM. (Since
they are not tied to HW, we keep the i915 prefix as opposed to intel.)

In short, the spatch:
@@

@@
- struct drm_i915_gem_request
+ struct i915_request

A corollary to contracting the type name, we also harmonise on using
'rq' shorthand for local variables where space if of the essence and
repetition makes 'request' unwieldy. For globals and struct members,
'request' is still much preferred for its clarity.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180221095636.6649-1-chris@chris-wilson.co.ukReviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: NMichał Winiarski <michal.winiarski@intel.com>
Acked-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

When dumping the engine, we print out the current register values. This
requires the rpm wakeref. If the device is alseep, we can assume the
engine is asleep (and the register state is uninteresting) so skip and
only acquire the rpm wakeref if the device is already awake.
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>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180212102415.24246-1-chris@chris-wilson.co.uk

If the entire device is powered off, we can safely assume that the
engine is also asleep (and idle).
Reported-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Fixes: a091d4ee ("drm/i915: Hold a wakeref for probing the ring registers")
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@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180212093928.6005-1-chris@chris-wilson.co.uk

Since commit 4a118ecb ("drm/i915: Filter out spurious execlists
context-switch interrupts") we probe execlists->active, and no longer
have to peek at the execlist interrupt to determine if the tasklet still
needs to be run to drain the ELSP.

References: 4a118ecb ("drm/i915: Filter out spurious execlists context-switch interrupts")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Michal Winiarski <michal.winiarski@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180208151224.16285-1-chris@chris-wilson.co.uk

If we remove some hardcoded assumptions about the preempt context having
a fixed id, reserved from use by normal user contexts, we may only
allocate the i915_gem_context when required. Then the subsequent
decisions on using preemption reduce to having the preempt context
available.

v2: Include an assert that we don't allocate the preempt context twice.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Michal Winiarski <michal.winiarski@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Acked-by: NDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180207210544.26351-3-chris@chris-wilson.co.ukReviewed-by: NMichel Thierry <michel.thierry@intel.com>

We have a hole in our busy-stat accounting if the pmu is enabled during
a long running batch, the pmu will not start accumulating busy-time
until the next context switch. This then fails tests that are only
sampling a single batch.

v2: Count each active port just once (context in/out events are only on
the first and last assignment to a port).
v3: Avoid hardcoding knowledge of 2 submission ports

Fixes: 30e17b78 ("drm/i915: Engine busy time tracking")
Testcase: igt/perf_pmu/busy-start
Testcase: igt/perf_pmu/busy-double-start
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: https://patchwork.freedesktop.org/patch/msgid/20180111073031.14614-1-chris@chris-wilson.co.uk
(cherry picked from commit 4900727d)
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>

Render engine constructor helpers must only be called from the render
engine constructors, but there is no need to burden the production
binaries with warnings which can only be triggered during development.
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Michel Thierry <michel.thierry@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMichel Thierry <michel.thierry@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180119100005.9072-1-tvrtko.ursulin@linux.intel.com

Gen11 removes the Resource Streamer, which frees up a big chunk of
the context image. BSpec indicates 12544 DWORDs (13 pages), plus
one page for PPHWSP.

Please notice that, when looking at the BSpec context image table,
the right filter has to be applied as some rows are excluded for
specific GENs. Also, some rows apply per-subslice (for the
calculation above, we have supposed I915_MAX_SUBSLICES = 8).

v2: Rebase.
v3: Use the right size as per the BSpec.
v4:
  - Rebased on top of the default context size (Rodrigo)
  - Clarify in the commit message where the subslice calculation
    comes from.
v5: s/12538/12544/ (Daniele)

BSpec: 18907

Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: Ben Widawsky <benjamin.widawsky@intel.com> (older version)
Reviewed-by: NDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1515711307-28979-2-git-send-email-oscar.mateo@intel.com

Instead of returning whatever size the latest GEN used. This is because
context sizes for new GENs can go up or down, but the only safe thing to
do for missing cases is to use the largest known one, whatever that is.
Suggested-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: NDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: NOscar Mateo <oscar.mateo@intel.com>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1515711307-28979-1-git-send-email-oscar.mateo@intel.com

In order to prevent a race condition where we may end up overaccounting
the active state and leaving the busy-stats believing the GPU is 100%
busy, lock out the tasklet while we reconstruct the busy state. There is
no direct spinlock guard for the execlists->port[], so we need to
utilise tasklet_disable() as a synchronous barrier to prevent it, the
only writer to execlists->port[], from running at the same time as the
enable.

Fixes: 4900727d ("drm/i915/pmu: Reconstruct active state on starting busy-stats")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180115092041.13509-1-chris@chris-wilson.co.ukReviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

We have a hole in our busy-stat accounting if the pmu is enabled during
a long running batch, the pmu will not start accumulating busy-time
until the next context switch. This then fails tests that are only
sampling a single batch.

v2: Count each active port just once (context in/out events are only on
the first and last assignment to a port).
v3: Avoid hardcoding knowledge of 2 submission ports

Fixes: 30e17b78 ("drm/i915: Engine busy time tracking")
Testcase: igt/perf_pmu/busy-start
Testcase: igt/perf_pmu/busy-double-start
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: https://patchwork.freedesktop.org/patch/msgid/20180111073031.14614-1-chris@chris-wilson.co.uk

Geminilake requires the 3D driver to select whether barriers are
intended for compute shaders, or tessellation control shaders, by
whacking a "Barrier Mode" bit in SLICE_COMMON_ECO_CHICKEN1 when
switching pipelines.  Failure to do this properly can result in GPU
hangs.

Unfortunately, this means it needs to switch mid-batch, so only
userspace can properly set it.  To facilitate this, the kernel needs
to whitelist the register.

The workarounds page currently tags this as applying to Broxton only,
but that doesn't make sense.  The documentation for the register it
references says the bit userspace is supposed to toggle only exists on
Geminilake.  Empirically, the Mesa patch to toggle this bit appears to
fix intermittent GPU hangs in tessellation control shader barrier tests
on Geminilake; we haven't seen those hangs on Broxton.

v2: Mention WA #0862 in the comment (it doesn't have a name).
Signed-off-by: NKenneth Graunke <kenneth@whitecape.org>
Acked-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180105085905.9298-1-kenneth@whitecape.org
(cherry picked from commit ab062639)
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

Geminilake requires the 3D driver to select whether barriers are
intended for compute shaders, or tessellation control shaders, by
whacking a "Barrier Mode" bit in SLICE_COMMON_ECO_CHICKEN1 when
switching pipelines.  Failure to do this properly can result in GPU
hangs.

Unfortunately, this means it needs to switch mid-batch, so only
userspace can properly set it.  To facilitate this, the kernel needs
to whitelist the register.

The workarounds page currently tags this as applying to Broxton only,
but that doesn't make sense.  The documentation for the register it
references says the bit userspace is supposed to toggle only exists on
Geminilake.  Empirically, the Mesa patch to toggle this bit appears to
fix intermittent GPU hangs in tessellation control shader barrier tests
on Geminilake; we haven't seen those hangs on Broxton.

v2: Mention WA #0862 in the comment (it doesn't have a name).
Signed-off-by: NKenneth Graunke <kenneth@whitecape.org>
Acked-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180105085905.9298-1-kenneth@whitecape.org

Looking at a CI failure with an ominous line of
[  362.550715] hangcheck current seqno ffffff6b, last ffffff8c, hangcheck ffffff6b [6016 ms], inflight 118
with no apparent cause for the seqno to be negative, left me wondering
if someone had scribbled over the HWSP. So include the HWSP in the
engine dump to see if there are more signs of random scribbling.

v2: Fix row pointer, i is now incremented by 8 so doesn't need scaling
by 8, and we don't need to keep volatile here as the status_page isn't
marked up as volatile itself.
v3: Use hexdump, with suppression of identical lines. (Tvrtko)
    Which results in

HWSP:
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
*
00000040 00000001 00000000 00000018 00000002 00000001 00000000 00000018 00000000
00000060 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000003
00000080 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
*
000000c0 00000002 00000000 00000000 00000000 00000000 00000000 00000000 00000000
000000e0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
*

    instead of 128 lines of mostly 0s.
v4: Tidy up the locals
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: https://patchwork.freedesktop.org/patch/msgid/20171222182521.18106-1-chris@chris-wilson.co.ukReviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

There seems to be another clock gating issue which the workaround is
described as:

   "WA: Set 0xE4F0[1] = 1 to disable Early EOT of thread."
Signed-off-by: NRafael Antognolli <rafael.antognolli@intel.com>
Reviewed-by: NLucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171216001117.14232-2-rafael.antognolli@intel.com

A useful bit of information for inspecting GPU stalls from
intel_engine_dump() are the error registers, IPEIR and IPEHR.

v2: Fixup gen changes in register offsets (Tvrtko)
v3: Old FADDR location as well
v4: Use I915_READ64_2x32
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171218123914.19027-1-chris@chris-wilson.co.ukReviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

i915_gem_wait_for_idle() is called from inside the shrinker, to ensure
that we drain the last resources from the GPU in dire circumstances (OOM).
As we may allocate whilst building a request, it is then possible to hit
the shrinker with a request under construction, and so we must account
for the incomplete request whilst waiting. In particular, we
preincrement (in reserve_engine) the i915->gt.active_requests counter
and mark the GPU as busy, therefore we can not use that counter for
shortcircuiting the wait-for-idle.

[  950.859024] GEM_BUG_ON(i915->gt.active_requests)
[  950.859041] WARNING: CPU: 2 PID: 2178 at drivers/gpu/drm/i915/i915_gem.c:3615 i915_gem_wait_for_idle.part.56+0x166/0x4e0
[  950.859041] Modules linked in: ccm tun fuse nf_conntrack_netbios_ns nf_conntrack_broadcast ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 nf_defrag_ipv6 nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack libcrc32c ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_mangle iptable_security iptable_raw arc4 iwldvm mac80211 snd_hda_codec_hdmi snd_hda_codec_idt snd_hda_codec_generic snd_hda_intel snd_hda_codec btusb snd_hda_core btrtl btbcm iwlwifi snd_hwdep btintel bluetooth snd_seq snd_seq_device snd_pcm ecdh_generic x86_pkg_temp_thermal tpm_infineon coretemp tpm_tis crc32_pclmul wmi_bmof crc32c_intel iTCO_wdt hp_wmi snd_timer iTCO_vendor_support sparse_keymap tpm_tis_core mei_me cfg80211
[  950.859082]  snd joydev tpm mei rfkill pcspkr wmi soundcore lpc_ich hp_accel lis3lv02d input_polldev binfmt_misc e1000e ptp serio_raw pps_core
[  950.859094] CPU: 2 PID: 2178 Comm: gem_exec_nop Tainted: G     U           4.15.0-rc2+ #900
[  950.859102] Hardware name: Hewlett-Packard HP ProBook 6360b/1620, BIOS 68SCF Ver. B.42 12/29/2010
[  950.859107] task: c5119cb4 task.stack: f3ccb8d8
[  950.859112] EIP: i915_gem_wait_for_idle.part.56+0x166/0x4e0
[  950.859113] EFLAGS: 00010296 CPU: 2
[  950.859114] EAX: 00000024 EBX: f36c1888 ECX: f777a044 EDX: 00000007
[  950.859115] ESI: f36c1888 EDI: edd53958 EBP: edd53970 ESP: edd53938
[  950.859116]  DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
[  950.859117] CR0: 80050033 CR2: b7f39000 CR3: 2f2b3000 CR4: 000406d0
[  950.859118] Call Trace:
[  950.859125]  ? drm_printk+0x70/0x70
[  950.859129]  i915_gem_wait_for_idle+0x18/0x30
[  950.859133]  i915_gem_shrink+0x360/0x410
[  950.859138]  ? vmpressure+0xa8/0xf0
[  950.859142]  ? ktime_get+0x4a/0x100
[  950.859147]  i915_gem_shrink_all+0x21/0x40
[  950.859151]  i915_gem_shrinker_oom+0x23/0x130
[  950.859156]  notifier_call_chain+0x4e/0x70
[  950.859160]  __blocking_notifier_call_chain+0x2f/0x60
[  950.859164]  blocking_notifier_call_chain+0x11/0x20
[  950.859169]  out_of_memory+0x207/0x280
[  950.859174]  __alloc_pages_nodemask+0xd47/0xe60
[  950.859179]  new_slab+0x32d/0x450
[  950.859183]  ___slab_alloc.constprop.81+0x358/0x4e0
[  950.859189]  ? i915_sw_fence_await_dma_fence+0x53/0x160
[  950.859193]  ? __slab_free+0x1fe/0x310
[  950.859197]  ? native_sched_clock+0x1e/0xc0
[  950.859201]  ? i915_gem_request_alloc+0xcf/0x510
[  950.859205]  ? sched_clock+0x9/0x10
[  950.859209]  __slab_alloc.constprop.80+0x29/0x40
[  950.859212]  ? __slab_alloc.constprop.80+0x29/0x40
[  950.859216]  kmem_cache_alloc_trace+0x160/0x1a0
[  950.859220]  ? i915_sw_fence_await_dma_fence+0x53/0x160
[  950.859224]  i915_sw_fence_await_dma_fence+0x53/0x160
[  950.859229]  i915_gem_request_await_dma_fence+0x1eb/0x390
[  950.859233]  i915_gem_request_await_object+0xee/0x230
[  950.859239]  i915_gem_do_execbuffer+0xc16/0x1200
[  950.859246]  ? irqtime_account_irq+0x3e/0xc0
[  950.859251]  ? irq_exit+0x4f/0xb0
[  950.859257]  ? smp_apic_timer_interrupt+0x5f/0x110
[  950.859261]  ? apic_timer_interrupt+0x35/0x3c
[  950.859266]  i915_gem_execbuffer2_ioctl+0x212/0x440
[  950.859270]  ? apic_timer_interrupt+0x35/0x3c
[  950.859274]  ? i915_gem_do_execbuffer+0x1200/0x1200
[  950.859279]  ? insn_get_seg_base+0x1b/0x50
[  950.859283]  ? i915_gem_do_execbuffer+0x1200/0x1200
[  950.859287]  drm_ioctl_kernel+0x51/0xa0
[  950.859291]  drm_ioctl+0x2a3/0x350
[  950.859294]  ? i915_gem_do_execbuffer+0x1200/0x1200
[  950.859300]  ? sched_clock+0x9/0x10
[  950.859303]  ? drm_getunique+0x70/0x70
[  950.859308]  do_vfs_ioctl+0x7d/0x640
[  950.859311]  ? native_sched_clock+0x1e/0xc0
[  950.859315]  ? sched_clock+0x9/0x10
[  950.859319]  ? sched_clock_cpu+0x13/0x120
[  950.859323]  SyS_ioctl+0x4e/0x80
[  950.859326]  do_fast_syscall_32+0x75/0x250
[  950.859331]  ? irq_exit+0x4f/0xb0
[  950.859334]  entry_SYSENTER_32+0x47/0x71
[  950.859338] EIP: 0xb7f81d11
[  950.859339] EFLAGS: 00000296 CPU: 2
[  950.859340] EAX: ffffffda EBX: 00000003 ECX: 40406469 EDX: bfde4c20
[  950.859340] ESI: 00000003 EDI: 40406469 EBP: 00000003 ESP: bfde4b38
[  950.859341]  DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 007b
[  950.859343] Code: e8 30 60 01 00 83 c4 10 83 c3 04 39 f3 75 e0 8b 45 d8 8b 80 14 37 00 00 85 c0 74 13 68 dd 33 e4 c0 68 49 6f e3 c0 e8 4a 55 be ff <0f> ff 5e 5f b8 fe ff ff 3f bb 0a 00 00 00 e8 b7 14 c4 ff 8b 15
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171212132148.8124-1-chris@chris-wilson.co.ukReviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

Since the seqno information shown from i915_interrupt_info is just a
small subset of i915_engine_info, remove it.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171209104418.4223-2-chris@chris-wilson.co.uk

Comparing the state tested by intel_engine_is_idle() and printed by
intel_engine_dump(), the only bit not shown is whether or not the device
is wedged. Add that little bit of information to the pretty printer so
that if the engine fails to idle we can see why.
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: https://patchwork.freedesktop.org/patch/msgid/20171208012303.25504-5-chris@chris-wilson.co.uk

Since a global reset affects the engine, include that along side the
per-engine reset counter when pretty printing the engine state in
intel_engine_dump().
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: https://patchwork.freedesktop.org/patch/msgid/20171208012303.25504-4-chris@chris-wilson.co.uk

Now that we have a common engine state pretty printer, we can use that
instead of the adhoc information printed when we miss a breadcrumb.

v2: Rearrange intel_engine_disarm_breadcrumbs() to avoid calling
intel_engine_dump() under the rb spinlock (Mika) and to pretty-print the
error state early so that we include the full list of waiters.
v3: Pass missed breadcrumb msg to pretty-printer as the header
v4: Preserve DRM_DEBUG_DRIVER filtering.
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: NMika Kuoppala <mika.kuoppala@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171208012303.25504-3-chris@chris-wilson.co.uk

Pass in a format string (and args) to specify the header to be emitted
along with the engine state when pretty-printing. This allows the header
to be emitted inside the drm_printer stream, so sharing the same prefix
and output characteristics (e.g. debug level and filtering).
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171208012303.25504-2-chris@chris-wilson.co.uk

When printing the execlist ports, we first print the ELSP header then
follow it with the pretty-printed request. Since switching to
drm_printer and show the output via printk, it automatically appends a
newline to each call (unlike the old seq_printf output). To avoid the
unwanted line break, construct the ELSP request header in a temporary
buffer.
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: https://patchwork.freedesktop.org/patch/msgid/20171208012303.25504-1-chris@chris-wilson.co.uk

Testing the texture read performance shows that the same tuning for
the SQ credits is needed on GLK as on BXT/APL. This has been also
confirmed by Altug from the HW team.

V4: Rebase + fix
Signed-off-by: NValtteri Rantala <valtteri.rantala@intel.com>
Reviewed-by: David Weinehall <david.weinehall@linux.intel.com> (v1)
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1511880305-12166-1-git-send-email-valtteri.rantala@intel.com

Sagar noticed the check can be consolidated between the engine stats
implementation and the PMU.

My first choice was a static inline helper but that got into include
ordering mess quickly fast so I went with a macro instead. At some point
we should perhaps looking into taking out the non-ringubffer bits from
intel_ringbuffer.h into a new intel_engine.h or something.

v2: Use engine->flags. (Chris Wilson)
v3: Rebase and mark GuC as not yet supported. (Chris Wilson)
v4: Move flag setting to intel_engines_reset_default_submission.
    (Chris Wilson)
v5: Move flag setting to logical_ring_setup.
v6: intel_engines_reset_default_submission is the wrong place to set the
    flag - it needs to be in execlists_set_default_submission. (Sagar)
v7: Flag setting in logical_ring_setup is not required. (Chris)
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Suggested-by: NSagar Arun Kamble <sagar.a.kamble@intel.com>
Cc: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Sagar Arun Kamble <sagar.a.kamble@intel.com> (v6)
Link: https://patchwork.freedesktop.org/patch/msgid/20171129102805.22690-1-tvrtko.ursulin@linux.intel.com

Track total time requests have been executing on the hardware.

We add new kernel API to allow software tracking of time GPU
engines are spending executing requests.

Both per-engine and global API is added with the latter also
being exported for use by external users.

v2:
 * Squashed with the internal API.
 * Dropped static key.
 * Made per-engine.
 * Store time in monotonic ktime.

v3: Moved stats clearing to disable.

v4:
 * Comments.
 * Don't export the API just yet.

v5: Whitespace cleanup.

v6:
 * Rename ref to active.
 * Drop engine aggregate stats for now.
 * Account initial busy period after enabling stats.

v7:
 * Rebase.

v8:
 * Move context in notification after the notifier. (Chris Wilson)

v9:

In cases where stats tracking is getting disabled while there is
an active context on an engine, add up the current value to the
total. This also implies we don't clear the total when tracking
is disabled any longer. There is no real need to do so because
we define the stats as relative while enabled, meaning
comparison between two samples while tracking is enabled is the
valid usage. However, when busy stats will later be plugged into
the perf PMU API, it is beneficial to not reset the total, since
the PMU core likes to do some counter disable/enable cycles on
startup, and while doing so during a single long context
executing on an engine we would lose some accuracy and so make
unit testing more difficult than needs to be.

v10:
 * Fix accounting for preemption.

v11:
 * Rebase for i915_modparams.enable_execlists removal.
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20171121181852.16128-5-tvrtko.ursulin@linux.intel.com

From: Chris Wilson <chris@chris-wilson.co.uk>
From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
From: Dmitry Rogozhkin <dmitry.v.rogozhkin@intel.com>

The first goal is to be able to measure GPU (and invidual ring) busyness
without having to poll registers from userspace. (Which not only incurs
holding the forcewake lock indefinitely, perturbing the system, but also
runs the risk of hanging the machine.) As an alternative we can use the
perf event counter interface to sample the ring registers periodically
and send those results to userspace.

Functionality we are exporting to userspace is via the existing perf PMU
API and can be exercised via the existing tools. For example:

  perf stat -a -e i915/rcs0-busy/ -I 1000

Will print the render engine busynnes once per second. All the performance
counters can be enumerated (perf list) and have their unit of measure
correctly reported in sysfs.

v1-v2 (Chris Wilson):

v2: Use a common timer for the ring sampling.

v3: (Tvrtko Ursulin)
 * Decouple uAPI from i915 engine ids.
 * Complete uAPI defines.
 * Refactor some code to helpers for clarity.
 * Skip sampling disabled engines.
 * Expose counters in sysfs.
 * Pass in fake regs to avoid null ptr deref in perf core.
 * Convert to class/instance uAPI.
 * Use shared driver code for rc6 residency, power and frequency.

v4: (Dmitry Rogozhkin)
 * Register PMU with .task_ctx_nr=perf_invalid_context
 * Expose cpumask for the PMU with the single CPU in the mask
 * Properly support pmu->stop(): it should call pmu->read()
 * Properly support pmu->del(): it should call stop(event, PERF_EF_UPDATE)
 * Introduce refcounting of event subscriptions.
 * Make pmu.busy_stats a refcounter to avoid busy stats going away
   with some deleted event.
 * Expose cpumask for i915 PMU to avoid multiple events creation of
   the same type followed by counter aggregation by perf-stat.
 * Track CPUs getting online/offline to migrate perf context. If (likely)
   cpumask will initially set CPU0, CONFIG_BOOTPARAM_HOTPLUG_CPU0 will be
   needed to see effect of CPU status tracking.
 * End result is that only global events are supported and perf stat
   works correctly.
 * Deny perf driver level sampling - it is prohibited for uncore PMU.

v5: (Tvrtko Ursulin)

 * Don't hardcode number of engine samplers.
 * Rewrite event ref-counting for correctness and simplicity.
 * Store initial counter value when starting already enabled events
   to correctly report values to all listeners.
 * Fix RC6 residency readout.
 * Comments, GPL header.

v6:
 * Add missing entry to v4 changelog.
 * Fix accounting in CPU hotplug case by copying the approach from
   arch/x86/events/intel/cstate.c. (Dmitry Rogozhkin)

v7:
 * Log failure message only on failure.
 * Remove CPU hotplug notification state on unregister.

v8:
 * Fix error unwind on failed registration.
 * Checkpatch cleanup.

v9:
 * Drop the energy metric, it is available via intel_rapl_perf.
   (Ville Syrjälä)
 * Use HAS_RC6(p). (Chris Wilson)
 * Handle unsupported non-engine events. (Dmitry Rogozhkin)
 * Rebase for intel_rc6_residency_ns needing caller managed
   runtime pm.
 * Drop HAS_RC6 checks from the read callback since creating those
   events will be rejected at init time already.
 * Add counter units to sysfs so perf stat output is nicer.
 * Cleanup the attribute tables for brevity and readability.

v10:
 * Fixed queued accounting.

v11:
 * Move intel_engine_lookup_user to intel_engine_cs.c
 * Commit update. (Joonas Lahtinen)

v12:
 * More accurate sampling. (Chris Wilson)
 * Store and report frequency in MHz for better usability from
   perf stat.
 * Removed metrics: queued, interrupts, rc6 counters.
 * Sample engine busyness based on seqno difference only
   for less MMIO (and forcewake) on all platforms. (Chris Wilson)

v13:
 * Comment spelling, use mul_u32_u32 to work around potential GCC
   issue and somne code alignment changes. (Chris Wilson)

v14:
 * Rebase.

v15:
 * Rebase for RPS refactoring.

v16:
 * Use the dynamic slot in the CPU hotplug state machine so that we are
   free to setup our state as multi-instance. Previously we were re-using
   the CPUHP_AP_PERF_X86_UNCORE_ONLINE slot which is neither used as
   multi-instance, nor owned by our driver to start with.
 * Register the CPU hotplug handlers after the PMU, otherwise the callback
   will get called before the PMU is initialized which can end up in
   perf_pmu_migrate_context with an un-initialized base.
 * Added workaround for a probable bug in cpuhp core.

v17:
 * Remove workaround for the cpuhp bug.

v18:
 * Rebase for drm_i915_gem_engine_class getting upstream before us.

v19:
 * Rebase. (trivial)
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NDmitry Rogozhkin <dmitry.v.rogozhkin@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Dmitry Rogozhkin <dmitry.v.rogozhkin@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171121181852.16128-2-tvrtko.ursulin@linux.intel.com

Having disabled the broken semaphores on Sandybridge, there is no need
for a modparam any more, so remove it in favour of a simple
HAS_LEGACY_SEMAPHORES() guard.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171120205504.21892-5-chris@chris-wilson.co.uk

As the semaphores is just part of the engine, include it with the
general pretty printer universally used for debugging.
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: https://patchwork.freedesktop.org/patch/msgid/20171120205504.21892-4-chris@chris-wilson.co.uk

Since removing the module parameter to force selection of ringbuffer
emission for gen8, the code is defunct. Remove it.

To put the difference into perspective, a couple of microbenchmarks
(bdw i7-5557u, 20170324):
                                        ring          execlists
exec continuous nops on all rings:   1.491us            2.223us
exec sequential nops on each ring:  12.508us           53.682us
single nop + sync:                   9.272us           30.291us

vblank_mode=0 glxgears:            ~11000fps           ~9000fps

Since the earlier submission, gen8 ringbuffer submission has fallen
further and further behind in features. So while ringbuffer may hold the
throughput crown, in terms of interactive latency, execlists is much
better. Alas, we have no convenient metrics for such, other than
demonstrating things we can do with execlists but can not using
legacy ringbuffer submission.

We have made a few improvements to lowlevel execlists throughput,
and ringbuffer currently panics on boot! (bdw i7-5557u, 20171026):

                                        ring          execlists
exec continuous nops on all rings:       n/a            1.921us
exec sequential nops on each ring:       n/a           44.621us
single nop + sync:                       n/a           21.953us

vblank_mode=0 glxgears:                  n/a          ~18500fps

References: https://bugs.freedesktop.org/show_bug.cgi?id=87725Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Once-upon-a-time-Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171120205504.21892-2-chris@chris-wilson.co.uk

Execlists and legacy ringbuffer submission are no longer feature
comparable (execlists now offer greater functionality that should
overcome their performance hit) and obsoletes the unsafe module
parameter, i.e. comparing the two modes of execution is no longer
useful, so remove the debug tool.
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>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com> #i915_perf.c
Link: https://patchwork.freedesktop.org/patch/msgid/20171120205504.21892-1-chris@chris-wilson.co.uk

intel_lrc_irq_handler and i915_guc_irq_handler are HW submission related
tasklet functions. Name them with "submission_tasklet" suffix and
remove intel/i915 prefix as they are static. Also rename irq_tasklet
as just tasklet for clarity.

v2: s/_bh/_tasklet (Chris)
Suggested-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: NSagar Arun Kamble <sagar.a.kamble@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Michal Winiarski <michal.winiarski@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/1510839162-25197-2-git-send-email-sagar.a.kamble@intel.comSigned-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Having removed the preproduction Broxton support (see commit 0102ba1f
("drm/i915: Add early BXT sdv to the list of preproduction machines")),
we know we then always need the production Broxton workaround set and do
not need a predicate upon revision.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171114134340.5439-2-chris@chris-wilson.co.uk

We've begun excluding pre-production Broxton machines since commit
0102ba1f ("drm/i915: Add early BXT sdv to the list of preproduction
machines"), now remove the list of workaround register values for those
early machines.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20170927093325.24206-1-chris@chris-wilson.co.ukReviewed-by: NJani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171114134340.5439-1-chris@chris-wilson.co.uk

gem_workarounds reports that the SLICE_UNIT_LEVEL_CLKGATE write isn't
sticking. Commit 0a60797a ("drm/i915: Implement
ReadHitWriteOnlyDisable.") presumes that SLICE_UNIT_LEVEL_CLKGATE is a
masked register in the context image, but commit 90007bca
("drm/i915/cnl: Introduce initial Cannonlake Workarounds.") lists it as
an ordering unmasked register. The masked write will be losing the
default settings if we trust the original commit. That gem_workarounds
reports the value is lost entirely is more worrying though -- but it
clearly suggests that it is not a masked register in the context image,
so unify both w/a to use the original rmw.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=103705
Fixes: 0a60797a ("drm/i915: Implement ReadHitWriteOnlyDisable.")
References: 90007bca ("drm/i915/cnl: Introduce initial Cannonlake Workarounds.")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Rafael Antognolli <rafael.antognolli@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Oscar Mateo <oscar.mateo@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171111100336.11020-1-chris@chris-wilson.co.ukReviewed-by: NRafael Antognolli <rafael.antognolli@intel.com>

From gen6, the hardware tracks address lookup failures and we should
clear those registers upon startup to prevent false positives. However,
this was happening before we have the engines defined (intel_uncore_init())
and the for_each_engine loop was just a nop. The earliest we can call
this is inside intel_engines_init_mmio().
Suggested-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NMichel Thierry <michel.thierry@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20171111004448.12360-1-michel.thierry@intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>