Check we can indeed acquire a WB mapping of the context image on module
load. Later this will give us the opportunity to validate that we can
switch from WC to WB as required.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180914123504.2062-2-chris@chris-wilson.co.uk
Now that we reload both RING_HEAD and RING_TAIL when rebinding the
context, we do not need to scrub those registers immediately on resume.
v2: Handle the perma-pinned contexts.
v3: Set RING_TAIL on context-pin so that we always have known state in
the context image for the ring registers and all parties have similar
code (ripe for refactoring).
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180914123504.2062-1-chris@chris-wilson.co.uk
In order to reduce latency when checking for idle we kick the tasklet
directly. Sometimes this is not enough as it is queued on another cpu
and so to improve the accuracy of this idle-check (and so to reduce
latency overall by avoiding another pass, or worse declaring a timeout!)
wait for the tasklet to complete.
References: https://bugs.freedesktop.org/show_bug.cgi?id=107916
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Michel Thierry <michel.thierry@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180914080017.30308-2-chris@chris-wilson.co.uk
If we try and fail to allocate a i915_request, we apply some
backpressure on the clients to throttle the memory allocations coming
from i915.ko. Currently, we wait until completely idle, but this is far
too heavy and leads to some situations where the only escape is to
declare a client hung and reset the GPU. The intent is to only ratelimit
the allocation requests and to allow ourselves to recycle requests and
memory from any long queues built up by a client hog.
Although the system memory is inherently a global resources, we don't
want to overly penalize an unlucky client to pay the price of reaping a
hog. To reduce the influence of one client on another, we can instead of
waiting for the entire GPU to idle, impose a barrier on the local client.
(One end goal for request allocation is for scalability to many
concurrent allocators; simultaneous execbufs.)
To prevent ourselves from getting caught out by long running requests
(requests that may never finish without userspace intervention, whom we
are blocking) we need to impose a finite timeout, ideally shorter than
hangcheck. A long time ago Paul McKenney suggested that RCU users should
ratelimit themselves using judicious use of cond_synchronize_rcu(). This
gives us the opportunity to reduce our indefinite wait for the GPU to
idle to a wait for the RCU grace period of the previous allocation along
this timeline to expire, satisfying both the local and finite properties
we desire for our ratelimiting.
There are still a few global steps (reclaim not least amongst those!)
when we exhaust the immediate slab pool, at least now the wait is itself
decoupled from struct_mutex for our glorious highly parallel future!
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=106680
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180914080017.30308-1-chris@chris-wilson.co.uk
IPC may cause underflows if not used with dual channel symmetric
memory configuration. Disable IPC for non symmetric configurations in
affected platforms.
Display WA #1141
Changes Since V1:
- Re-arrange the code.
- update wrapper to return if memory is symmetric (Rodrigo)
Signed-off-by: Mahesh Kumar <mahesh1.kumar@intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180824093225.12598-6-mahesh1.kumar@intel.com
Memory with 16GB dimms require an increase of 1us in level-0 latency.
This patch implements the same.
Bspec: 4381
changes since V1:
- s/memdev_info/dram_info
- make skl_is_16gb_dimm pure function
Changes since V2:
- make is_16gb_dimm more generic
- rebase
Changes since V3:
- Simplify condition (Maarten)
Signed-off-by: Mahesh Kumar <mahesh1.kumar@intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180831110942.9234-1-mahesh1.kumar@intel.com
This patch adds support to decode system memory bandwidth and other
parameters for skylake and Gen9+ platforms, which will be used for
arbitrated display memory bandwidth calculation in GEN9 based
platforms and WM latency level-0 Work-around calculation on GEN9+.
Changes Since V1:
- s/memdev_info/dram_info
- create a struct to hold channel info
Changes Since V2:
- rewrite code to adhere i915 coding style
- not valid for GLK
Signed-off-by: Mahesh Kumar <mahesh1.kumar@intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180824093225.12598-3-mahesh1.kumar@intel.com
This patch adds support to decode system memory bandwidth and other
parameters for broxton platform, which will be used for arbitrated
display memory bandwidth calculation in GEN9 based platforms and
WM latency level-0 Work-around calculation on GEN9+ platforms.
Changes since V1:
- s/memdev_info/dram_info
Changes since V2:
- Adhere to i915 coding style (Rodrigo)
Signed-off-by: Mahesh Kumar <mahesh1.kumar@intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180824093225.12598-2-mahesh1.kumar@intel.com
Add Support to load DMC on Icelake.
While at it, also add support to load the firmware
during system resume.
v2: load firmware during system resume.(Imre)
v3: enable has_csr for icelake.(Jyoti)
v4: Only load the firmware in this patch
Cc: Jyoti Yadav <jyoti.r.yadav@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Anusha Srivatsa <anusha.srivatsa@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180828003844.4682-2-anusha.srivatsa@intel.com
If we have framebuffers that are >= 4GiB in size we will overflow
the fb size check in intel_fill_fb_info().
Currently that is only possible with NV12 and CCS as offsets[1]
may be anything between 0 and 0xffffffff. offsets[0] is currently
required to be 0 so we can't hit the overflow with any single
plane format (thanks to max fb size of 8kx8k and max stride of
32 KiB).
In the future we may allow almost any framebuffer to exceed 4GiB
in size so we really should fix the overflow. Not that the overflow
is particularly dangerous. It's mostly just a sanity check against
insane userspace. The display engine can't write to memory anyway
so I suppose in the worst case we might anger the hw by attempting
scanout past the end of the ggtt, or we might scan out some data
that we're not supposed to see from other parts of the ggtt.
Note that triggering this overflow depends on the driver
aligning the fb height to the next tile boundary to push the
calculated size above 4GiB. With linear buffers the effective
tile height is one so that never happens, and the core already
has a check for 32bit overflow of offsets[]+pitches[]*height.
v2: Drop the unnecessary cast (Chris)
Testcase: igt/kms_big_fb/x-tiled-addfb-size-offset-overflow
Testcase: igt/kms_big_fb/y-tiled-addfb-size-offset-overflow
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180912180443.28649-1-ville.syrjala@linux.intel.com
Use I915_GTT_PAGE_SIZE when talking about GTT pages rather than
physical pages.
There are some PAGE_SHIFTs left though. Not sure if we want to
introduce I915_GTT_PAGE_SHIFT or what?
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Suggested-by: Chris Wilson <chris@chris-wilson.co.uk> # at least some of it :)
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180913150405.706-1-ville.syrjala@linux.intel.com
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
We can remove the update-via-batch-buffer code path, which is basically an
effective duplicate of update-via-context-image path, if we notice that
after we have idled the GPU, we can update the context image even of the
kernel context directly. (Update-via-batch-buffer path existed only to
solve the problem of how to update the kernel context image.)
Only additional thing needed is to activate the edited configuration by
sending one empty request down the pipe. This accomplishes context restore
of the updated kernel context and so the OA configuration gets written out
to it's control registers.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180912152930.28237-1-tvrtko.ursulin@linux.intel.com
Move the display w/a #1175 to a better place. That place
being the new skl+ specific plane->check() hook. This leaves
the skl_check_plane_surface() stuff to deal with the gtt offset
and src coordinate stuff as originally envisioned.
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180907152413.15761-12-ville.syrjala@linux.intel.com
Move the skl+ specific framebuffer related checks from
intel_plane_atomic_check_with_state() into a new function
(skl_plane_check_fb()) which we'll simply call from the skl
plane->check() hook.
v2: Split out the Y/Yf+CCS vs. interlaced change (José)
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180907152413.15761-11-ville.syrjala@linux.intel.com
Split up intel_check_primary_plane() and intel_check_sprite_plane()
into per-platform variants. This way we can get a unified behaviour
between the SKL universal planes, and we stop checking for non-SKL
specific scaling limits for the "sprite" planes. And we now get
a natural place where to add more plarform specific checks.
v2: Split the .check_plane() calling convention change out (José)
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180907152413.15761-10-ville.syrjala@linux.intel.com
We can easily calculate the plane can_scale/min_downscale on demand.
And later on we'll probably want to start calculating these dynamically
based on the cdclk just as skl already does.
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180907152413.15761-9-ville.syrjala@linux.intel.com
Let's store the final plane stride in the plane state. This avoids
having to pick between the normal vs. rotated stride during hardware
programming. And once we get GTT remapping the plane stride will
no longer match the fb stride so we'll need a place to store it
anyway.
v2: Keep checking fb->pitches[0] for cursor as later on we won't
populate plane_state->color_plane[0].stride for invisible planes
and we have been checking the cursor fb stride even for invisible
planes
v3: s/betwen/between in commit msg (José)
v4: Check color_plane[0].stride instead of fb->pitches[0] in
the skl_check_main_surface() X-tiling kludge
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180911150139.23922-1-ville.syrjala@linux.intel.com
Each plane may have different stride limitations. Let's add a new
plane function to retutn the maximum stride for each plane. There's
going to be some use for this outside the .atomic_check() stuff hence
the separate hook.
v2: Fix ilk+ x-tiled max stride to be 32k (José)
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180907152413.15761-3-ville.syrjala@linux.intel.com
Rename some of the tile_offset() functions to aligned_offset() since
they operate on both linear and tiled functions. And we'll include
_plane_ in the name of all the variants that take a plane state.
Should make it more clear which function to use where.
v2: Pimp the patch subject a bit (José)
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180907152413.15761-2-ville.syrjala@linux.intel.com
If the caller supplies more than 4G of objects and than one that has to
be in the low 4G, it is possible for the low 4G to be full before we
attempt to find room for the last object that must be there. As we don't
reorder the two types, every pass hits the same problem and we fail with
ENOSPC. However, if we impose a little bit of ordering between the two
classes of objects, on the second pass we will be able to fit the
special object as we do it first. For setups that only use !48b objects,
we now reverse the order between passes, hopefully making the subsequent
passes more likely to succeed given that we are trying a different
order (rather than repeating the previous pass!)
v2: Quick one line explanation for the relative priorities given to
reservations.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180912101133.31377-1-chris@chris-wilson.co.uk
Userspace should be free to race against itself and shoot itself in
the foot if it so desires to adjust a parameter at the same time as
submitting a batch to that context. As such, the struct_mutex in context
setparam is only being used to serialise userspace against itself and
not for any protection of internal structs and so is superfluous.
v2: Separate user_flags from internal flags to reduce chance of
interference; and use locked bit ops for user updates.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180911132206.23032-1-chris@chris-wilson.co.uk
The user parameters to put_image are not copied back to userspace
(DRM_IOW), and so we can modify the ioctl parameters (having already been
copied to a temporary kernel struct) directly and use those in place,
avoiding another temporary malloc and lots of manual copying.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180906190144.1272-2-chris@chris-wilson.co.uk
Given that we are now reasonably confident in our ability to detect and
reserve the stolen memory (physical memory reserved for graphics by the
BIOS) for ourselves on most machines, we can put it to use. In this
case, we need a page to hold the overlay registers.
On an i915g running MythTv, H Buus noticed that
commit 6a2c4232ec
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date: Tue Nov 4 04:51:40 2014 -0800
drm/i915: Make the physical object coherent with GTT
introduced stuttering into his video playback. After discarding the
likely suspect of it being the physical cursor updates, we were left
with the use of the phys object for the overlay. And lo, if we
completely avoid using the phys object (allocated just once on module
load!) by switching to stolen memory, the stuttering goes away.
For lack of a better explanation, claim victory and kill two birds with
one stone.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107600
Fixes: 6a2c4232ec ("drm/i915: Make the physical object coherent with GTT")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180906190144.1272-1-chris@chris-wilson.co.uk
During modeset, previously configured csc coefficient matrix,if any, will
not persist. This can result in blank screen as csc mode will be programmed
while loading LUT but csc coefficient matrix remains unprogrammed.
Changes since V1:
- Removed platform check
Signed-off-by: P Raviraj Sitaram <raviraj.p.sitaram@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1536589634-29680-1-git-send-email-raviraj.p.sitaram@intel.com
We should update GuC power domain states also when GuC submission
is disabled, otherwise GuC might complain or ignore our requests.
This seems to be required for all currently released GuC firmwares.
v2: it is only needed by pre-Gen11 firmwares
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: John Spotswood <john.a.spotswood@intel.com>
Cc: Anusha Srivatsa <anusha.srivatsa@intel.com>
Cc: Tomasz Lis <tomasz.lis@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Anusha Srivatsa <anusha.srivatsa@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180910104150.101752-1-michal.wajdeczko@intel.com
Using the guc, we cannot disable the user interrupt generation as we use
it for driving submission. And from Icelake, we no longer have the
ability to individually mask interrupt generation from each engine,
disabling our ability to fake missed interrupts.
In both cases, report back to userspace that the missed interrupt
generator is no longer available.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180907112856.28242-1-chris@chris-wilson.co.uk
Introduce a complementary function to i915_driver_create() to undo all
that is created.
Suggested-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180905140921.17467-2-chris@chris-wilson.co.uk
Future gen reduce the number of bits we will have available to
differentiate between contexts, so reduce the lifetime of the ID
assignment from that of the context to its current active cycle (i.e.
only while it is pinned for use by the HW, will it have a constant ID).
This means that instead of a max of 2k allocated contexts (worst case
before fun with bit twiddling), we instead have a limit of 2k in flight
contexts (minus a few that have been pinned by the kernel or by perf).
To reduce the number of contexts id we require, we allocate a context id
on first and mark it as pinned for as long as the GEM context itself is,
that is we keep it pinned it while active on each engine. If we exhaust
our context id space, then we try to reclaim an id from an idle context.
In the extreme case where all context ids are pinned by active contexts,
we force the system to idle in order to recover ids.
We cannot reduce the scope of an HW-ID to an engine (allowing the same
gem_context to have different ids on each engine) as in the future we
will need to preassign an id before we know which engine the
context is being executed on.
v2: Improved commentary (Tvrtko) [I tried at least]
References: https://bugs.freedesktop.org/show_bug.cgi?id=107788
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Michel Thierry <michel.thierry@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180904153117.3907-1-chris@chris-wilson.co.uk
If the previous modeset commit has completed and is no longer part of
the crtc state, skip waiting for it.
Ville pointed out that, in fact, the commit is never removed after a
modeset so the only way we could see a NULL here should be if there was
never a commit attached. Nevertheless, we have the evidence it can be
NULL and it has been defended against elsewhere, for example commit
93313538c1 ("drm/i915: Pass idle crtc_state to intel_dp_sink_crc").
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107792
Fixes: c44301fce6 ("drm/i915: Allow control of PSR at runtime through debugfs, v6")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180904162902.2578-1-chris@chris-wilson.co.uk
Elsewhere we manipulate uncore.unclaimed_mmio_check and
i915_param.mmio_debug under the irq lock (e.g. preserving the current
value across a user forcewake grab), but do not protect the manipulation
inside intel_uncore_arm_unclaimed_mmio_detection() from concurrent
access, even from itself. This is an issue as we do call
arm_unclaimed_mmio_detection from multiple threads without coordination.
Suggested-by: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intelcom>
Link: https://patchwork.freedesktop.org/patch/msgid/20180904131207.17563-1-chris@chris-wilson.co.uk
There are two issues with the current RPCS programming for Icelake:
Expansion of the slice count bitfield has been missed, as well as the
required programming workaround for the subslice count bitfield size
limitation.
1)
Bitfield width for configuring the active slice count has grown so we need
to program the GEN8_R_PWR_CLK_STATE accordingly.
Current code was always requesting eight times the number of slices (due
writing to a bitfield starting three bits higher than it should). These
requests were luckily a) capped by the hardware to the available number of
slices, and b) we haven't yet exported the code to ask for reduced slice
configurations.
Due both of the above there was no impact from this incorrect programming
but we should still fix it.
2)
Due subslice count bitfield being only three bits wide and furthermore
capped to a maximum documented value of four, special programming
workaround is needed to enable more than four subslices.
With this programming driver has to consider the GT configuration as
2x4x8, while the hardware internally translates this to 1x8x8.
A limitation stemming from this is that either a subslice count between
one and four can be selected, or a subslice count equaling the total
number of subslices in all selected slices. In other words, odd subslice
counts greater than four are impossible, as are odd subslice counts
greater than a single slice subslice count.
This also had no impact in the current code base due breakage from 1)
always reqesting more than one slice.
While fixing this we also add some asserts to flag up any future bitfield
overflows.
v2:
* Use a local in all branches for clarity. (Lionel)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Bspec: 12247
Reported-by: tony.ye@intel.com
Suggested-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: tony.ye@intel.com
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180903113007.2643-1-tvrtko.ursulin@linux.intel.com
Continuing the fun of trying to find exactly the delay that is
sufficient to ensure that the page directory is fully loaded between
context switches, move the extra flush added in commit 70b73f9ac1
("drm/i915/ringbuffer: Delay after invalidating gen6+ xcs") to just
after we flush the pd. Entirely based on the empirical data of running
failing tests in a loop until we survive a day (before the mtbf is 10-30
minutes).
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107769
References: 70b73f9ac1 ("drm/i915/ringbuffer: Delay after invalidating gen6+ xcs")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180904063802.13880-1-chris@chris-wilson.co.uk
Currently, if the user has enabled mmio-debug around each register
access, we presume that we have then checked them all. However, it is
still possible through omission (raw register access) or external
interaction that the unclaimed access was not highlighted.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180904111732.24266-1-chris@chris-wilson.co.uk
