This is based on Mika Kuoppala's patch below:
http://article.gmane.org/gmane.comp.freedesktop.xorg.drivers.intel/61104/match=workaround+hw+preload

The patch will preallocate the page directories for 32-bit PPGTT when
i915 runs inside a virtual machine with Intel GVT-g. With this change,
the root pointers in EXECLIST context will always keep the same.

The change is needed for vGPU because Intel GVT-g will do page table
shadowing, and needs to track all the page table changes from guest
i915 driver. However, if guest PPGTT is modified through GPU commands
like LRI, it is not possible to trap the operations in the right time,
so it will be hard to make shadow PPGTT to work correctly.

Shadow PPGTT could be much simpler with this change. Meanwhile
hypervisor could simply prohibit any attempt of PPGTT modification
through GPU command for security.

The function gen8_preallocate_top_level_pdps() in the patch is from
Mika, with only one change to set "used_pdpes" to avoid duplicated
allocation later.

Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Dave Gordon <david.s.gordon@intel.com>
Cc: Michel Thierry <michel.thierry@intel.com>
Signed-off-by: NZhiyuan Lv <zhiyuan.lv@intel.com>
Signed-off-by: NZhi Wang <zhi.a.wang@intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

By running igt/store_dword_loop_render on BXT we can hit a coherency
problem where the seqno written at GPU command completion time is not
seen by the CPU. This results in __i915_wait_request seeing the stale
seqno and not completing the request (not considering the lost
interrupt/GPU reset mechanism). I also verified that this isn't a case
of a lost interrupt, or that the command didn't complete somehow: when
the coherency issue occured I read the seqno via an uncached GTT mapping
too. While the cached version of the seqno still showed the stale value
the one read via the uncached mapping was the correct one.

Work around this issue by clflushing the corresponding CPU cacheline
following any store of the seqno and preceding any reading of it. When
reading it do this only when the caller expects a coherent view.

v2:
- fix using the proper logical && instead of a bitwise & (Jani, Mika)
- limit the workaround to A stepping, on later steppings this HW issue
  is fixed
v3:
- use a separate get_seqno/set_seqno vfunc (Chris)

Testcase: igt/store_dword_loop_render
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

MI_STORE_REGISTER_MEM, MI_LOAD_REGISTER_MEM instructions are not really
variable length instructions unlike MI_LOAD_REGISTER_IMM where it expects
(reg, addr) pairs so use fixed length for these instructions.

v2: rebase

Cc: Dave Gordon <david.s.gordon@intel.com>
Signed-off-by: NArun Siluvery <arun.siluvery@linux.intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
[danvet: Appease checkpatch as Mika spotted in i915_reg.h - it seems
terminally unhappy about i915_cmd_parser.c so that would be a separate
patch.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

GuC-based submission is mostly the same as execlist mode, up to
intel_logical_ring_advance_and_submit(), where the context being
dispatched would be added to the execlist queue; at this point
we submit the context to the GuC backend instead.

There are, however, a few other changes also required, notably:
1.  Contexts must be pinned at GGTT addresses accessible by the GuC
    i.e. NOT in the range [0..WOPCM_SIZE), so we have to add the
    PIN_OFFSET_BIAS flag to the relevant GGTT-pinning calls.

2.  The GuC's TLB must be invalidated after a context is pinned at
    a new GGTT address.

3.  GuC firmware uses the one page before Ring Context as shared data.
    Therefore, whenever driver wants to get base address of LRC, we
    will offset one page for it. LRC_PPHWSP_PN is defined as the page
    number of LRCA.

4.  In the work queue used to pass requests to the GuC, the GuC
    firmware requires the ring-tail-offset to be represented as an
    11-bit value, expressed in QWords. Therefore, the ringbuffer
    size must be reduced to the representable range (4 pages).

v2:
    Defer adding #defines until needed [Chris Wilson]
    Rationalise type declarations [Chris Wilson]

v4:
    Squashed kerneldoc patch into here [Daniel Vetter]

v5:
    Update request->tail in code common to both GuC and execlist modes.
    Add a private version of lr_context_update(), as sharing the
        execlist version leads to race conditions when the CPU and
        the GuC both update TAIL in the context image.
    Conversion of error-captured HWS page to string must account
        for offset from start of object to actual HWS (LRC_PPHWSP_PN).

Issue: VIZ-4884
Signed-off-by: NAlex Dai <yu.dai@intel.com>
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Reviewed-by: NTom O'Rourke <Tom.O'Rourke@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

GuC submission is basically execlist submission, but with the GuC
handling the actual writes to the ELSP and the resulting context
switch interrupts.  So to describe a context for submission via
the GuC, we need one of the same functions used in execlist mode.
This commit exposes one such function, changing its name to better
describe what it does (it's related to logical ring contexts rather
than to execlists per se).

v2:
    Replaces previous "drm/i915: Move execlists defines from .c to .h"

v3:
    Incorporates a change to one of the functions exposed here that was
        previously part of an internal patch, but which was omitted from
        the version recently committed to drm-intel-nightly:
	    7a01a0a2 drm/i915/lrc: Update PDPx registers with lri commands
        So we reinstate this change here.

v4:
    Drop v3 change, update function parameters due to collision with
        8ee36152 drm/i915: Convert execlists_ctx_descriptor() for requests

v5:
    Don't expose execlists_update_context() after all. The current
        version is no longer compatible with GuC submission; trying to
        share the execlist version of this function results in both GuC
        and CPU updating TAIL in the context image, with bad results when
        they get out of step. The GuC submission path now has its own
        private version that just updates the ringbuffer start address,
        and not TAIL or PDPx.

v6:
    Rebased

Issue: VIZ-4884
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Reviewed-by: NTom O'Rourke <Tom.O'Rourke@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

In 64b (48bit canonical) PPGTT addressing, the PDP0 register contains
the base address to PML4, while the other PDP registers are ignored.

In LRC, the addressing mode must be specified in every context
descriptor, and the base address to PML4 is stored in the reg state.

v2: PML4 update in legacy context switch is left for historic reasons,
the preferred mode of operation is with lrc context based submission.
v3: s/gen8_map_page_directory/gen8_setup_page_directory and
s/gen8_map_page_directory_pointer/gen8_setup_page_directory_pointer.
Also, clflush will be needed for bxt. (Akash)
v4: Squashed lrc-specific code and use a macro to set PML4 register.
v5: Rebase after Mika's ppgtt cleanup / scratch merge patch series.
PDP update in bb_start is only for legacy 32b mode.
v6: Rebase after final merged version of Mika's ppgtt/scratch
patches.
v7: There is no need to update the pml4 register value in
execlists_update_context. (Akash)
v8: Move pd and pdp setup functions to a previous patch, they do not
belong here. (Akash)
v9: Check USES_FULL_48BIT_PPGTT instead of GEN8_CTX_ADDRESSING_MODE in
gen8_emit_bb_start to check if emit pdps is needed. (Akash)

Cc: Akash Goel <akash.goel@intel.com>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: Michel Thierry <michel.thierry@intel.com> (v2+)
Reviewed-by: NAkash Goel <akash.goel@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

If idle to active bit is set, the rest of the fields
in CSQ are not valid.

Bail out early if this is the case in order to prevent
rest of the loop inspecting stale values.

This was found by Bspec/code inspection. Doesn't seem to fix any of
the known issues.
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NArun Siluvery <arun.siluvery@linux.intel.com>
[danvet: Add note about how this was found.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This register needs to be updated with masked writes.

This was found by code inspection and comparison with Bspec and
doesn't seem to fix any known issue.
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NMichel Thierry <michel.thierry@intel.com>
[danvet: Add note about impact.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The Golden batch carries 3D state at the beginning so that HW starts with
a known state. It is carried as a binary blob which is auto-generated from
source. The idea was it would be easier to maintain and keep the complexity
out of the kernel which makes sense as we don't really touch it. However if
you really need to update it then you need to update generator source and
keep the binary blob in sync with it.

There is a need to patch this in bxt to send one additional command to enable
a feature. A solution was to patch the binary data with some additional
data structures (included as part of auto-generator source) but it was
unnecessarily complicated.

Chris suggested the idea of having a secondary batch and execute two batch
buffers. It has clear advantages as we needn't touch the base golden batch,
can customize secondary/auxiliary batch depending on Gen and can be carried
in the driver with no dependencies.

This patch adds support for this auxiliary batch which is inserted at the
end of golden batch and is completely independent from it. Thanks to Mika
for the preliminary review.

v2: Strictly conform to the batch size requirements to cover Gen2 and
add comments to clarify overflow check in macro (Chris, Mika).

v3: aux_batch_offset was declared as u64, change it to u32 (Chris)
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Armin Reese <armin.c.reese@intel.com>
Signed-off-by: NArun Siluvery <arun.siluvery@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

In Indirect context w/a batch buffer,
+WaSetDisablePixMaskCammingAndRhwoInCommonSliceChicken

v2: SKL revision id was used for BXT, copy paste error found during
internal review (Bob Beckett).

v3: explain why part of the WA is in Per ctx batch (Mika)

Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Signed-off-by: NArun Siluvery <arun.siluvery@linux.intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

In Indirect context w/a batch buffer,
+WaFlushCoherentL3CacheLinesAtContextSwitch:skl,bxt

v2: address static checker warning where unsigned value was checked for
less than zero which is never true (Dan Carpenter).

v3: The WA uses default value of GEN8_L3SQCREG4 during flush but that disables
some other WA; update default value to retain it and document dependency (Mika).

Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Signed-off-by: NArun Siluvery <arun.siluvery@linux.intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

In Indirect and Per context w/a batch buffer,
+WaDisableCtxRestoreArbitration

v2: SKL revision id was used for BXT, copy paste error found during
internal review (Bob Beckett).

v3: use updated macro.
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Cc: Robert Beckett <robert.beckett@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Signed-off-by: NArun Siluvery <arun.siluvery@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This patch only enables support for Gen9, the actual WA will be
initialized in subsequent patches.

The WARN that we use to warn user if WA batch support is not available
for a particular Gen is replaced with DRM_ERROR as warning here doesn't
really add much value.

v2: include all infrastructure bits in this patch so that subsequent
changes only correspond the WA added (Chris)

v3: use updated macro.
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NArun Siluvery <arun.siluvery@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This change adds the programming of the MOCS registers to the gen 9+
platforms. The set of MOCS configuration entries introduced by this
patch is intended to be minimal but sufficient to cover the needs of
current userspace - i.e. a good set of defaults. It is expected to be
extended in the future to provide further default values or to allow
userspace to redefine its private MOCS tables based on its demand for
additional caching configurations. In this setup, userspace should
only utilize the first N entries, higher entries are reserved for
future use.

It creates a fixed register set that is programmed across the different
engines so that all engines have the same table. This is done as the
main RCS context only holds the registers for itself and the shared
L3 values. By trying to keep the registers consistent across the
different engines it should make the programming for the registers
consistent.

v2:
-'static const' for private data structures and style changes.(Matt Turner)
v3:
- Make the tables "slightly" more readable. (Damien Lespiau)
- Updated tables fix performance regression.
v4:
- Code formatting. (Chris Wilson)
- re-privatised mocs code. (Daniel Vetter)
v5:
- Changed the name of a function. (Chris Wilson)
v6:
- re-based
- Added Mesa table entry (skylake & broxton) (Francisco Jerez)
- Tidied up the readability defines (Francisco Jerez)
- NUMBER of entries defines wrong. (Jim Bish)
- Added comments to clear up the meaning of the tables (Jim Bish)
Signed-off-by: NPeter Antoine <peter.antoine@intel.com>

v7 (Francisco Jerez):
- Don't write L3-specific MOCS_ESC/SCC values into the e/LLC control
  tables.  Prefix L3-specific defines consistently with L3_ and
  e/LLC-specific defines with LE_ to avoid this kind of confusion in
  the future.
- Change L3CC WT define back to RESERVED (matches my hardware
  documentation and the original patch, probably a misunderstanding
  of my own previous comment).
- Drop Android tables, define new minimal tables more suitable for the
  open source stack.
- Add comment that the MOCS tables are part of the kernel ABI.
- Move intel_logical_ring_begin() and _advance() calls one level down
  (Chris Wilson).
- Minor formatting and style fixes.
v8 (Francisco Jerez):
- Add table size sanity check to emit_mocs_control/l3cc_table() (Chris
  Wilson).
- Add comment about undefined entries being implicitly set to uncached
  for forwards compatibility.
v9 (Francisco Jerez):
- Minor style fixes.
Signed-off-by: NFrancisco Jerez <currojerez@riseup.net>
Acked-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

wa_ctx_emit() depends on the name of a local variable; if the name of that
variable is changed then we get compile errors. In this case it is unlikely
to be changed as this macro is only used in this set of functions but
Kernel coding guidelines doesn't recommend doing this. It was my mistake
as I should have corrected it at the beginning but missed so correct
this before there are more usages of this macro (Bob Beckett).

https://www.kernel.org/doc/Documentation/CodingStyle,
Chapter 12, "Things to avoid when using macros", point 2):

"
2) macros that depend on having a local variable with a magic name:

   #define FOO(val) bar(index, val)

might look like a good thing, but it's confusing as hell when one reads the
code and it's prone to breakage from seemingly innocent changes.
"

v2: Optimization to avoid multiple evaluation of 'index' in the macro.
Since we invoke it multiple times, compiler, if it can, should be able to coalesce
them into a single condition and remove multiple WARN_ON checks (Chris).
Suggested-by: NRobert Beckett <robert.beckett@intel.com>
Cc: Robert Beckett <robert.beckett@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Imre Deak <imre.deak@intel.com>
Signed-off-by: NArun Siluvery <arun.siluvery@linux.intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Now when we have requests this deep on call chain, we can mark
the elsp being submitted when it actually is. Remove temp variable
and readjust commenting to more closely fit to the code.

v2: Avoid tmp variable and reduce number of writes (Chris)

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

Pass around requests to carry context deeper in callchain.
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Pass around requests to carry context deeper in callchain.
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Pass around requests to carry context deeper in callchain.
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

In preparation to make intel_lr_context_pin|unpin to accept
requests, assign ringbuf into request before we call the pinning.

v2: No need to unset ringbuf on error path (Chris)

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

Pass around requests to carry context deeper in callchain.
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Pass around requests to carry context deeper in callchain.
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

In this WA we need to set GEN8_L3SQCREG4[21:21] and reset it after PIPE_CONTROL
instruction but there is a slight complication as this is applied in WA batch
where the values are only initialized once.
Dave identified an issue with the current implementation where the register value
is read once at the beginning and it is reused; this patch corrects this by saving
the register value to memory, update register with the bit of our interest and
restore it back with original value.

This implementation uses MI_LOAD_REGISTER_MEM which is currently only used
by command parser and was using a default length of 0. This is now updated
with correct length and moved to appropriate place.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Dave Gordon <david.s.gordon@intel.com>
Signed-off-by: NArun Siluvery <arun.siluvery@linux.intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

GEN8 and above uses Execlists by default instead of the legacy
ringbuffer for batch execution. This patch enables the resource
streamer bits when required.

Patch is based on the initial work by Minu Mathai <minu.mathai@intel.com>
This version also adds the required bits to enable GEN8 Resource
Streamer context save and restore for Execlists.

Cc: ville.syrjala@linux.intel.com
Signed-off-by: NAbdiel Janulgue <abdiel.janulgue@linux.intel.com>
Reviewed-by: NArun Siluvery <arun.siluvery@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

An earlier patch was added to reserve space in the ring buffer for the
commands issued during 'add_request()'. The initial version was
pessimistic in the way it handled buffer wrapping and would cause
premature wraps and thus waste ring space.

This patch updates the code to better handle the wrap case. It no
longer enforces that the space being asked for and the reserved space
are a single contiguous block. Instead, it allows the reserve to be on
the far end of a wrap operation. It still guarantees that the space is
available so when the wrap occurs, no wait will happen. Thus the wrap
cannot fail which is the whole point of the exercise.

Also fixed a merge failure with some comments from the original patch.

v2: Incorporated suggestion by David Gordon to move the wrap code
inside the prepare function and thus allow a single combined
wait_for_space() call rather than doing one before the wrap and
another after. This also makes the prepare code much simpler and
easier to follow.

v3: Fix for 'effective_size' vs 'size' during ring buffer remainder
calculations (spotted by Tomas Elf).

For: VIZ-5115
CC: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Reviewed-by: NTomas Elf <tomas.elf@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

A safer way to update the PDPx registers is sending lri commands, added
in the ring before the batchbuffer start. Otherwise, the ctx must be idle
before trying to change anything (but the ring-tail) in the ctx image. An
example where the ctx won't be idle is lite-restore.

This patch depends on 5b7e4c9c ("drm/i915/gtt: Mark TLBS dirty for gen8+").

v2: Combine lri writes (and save 8 commands). (Mika)
v3: Rebase after ring/req changes, and removed references to deprecated patches.

Cc: Dave Gordon <david.s.gordon@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NMichel Thierry <michel.thierry@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The legacy mode mm switch and the execlist context assignment
needs dma address for the page directories.

Introduce a function that encapsulates the scratch_pd dma
fallback if no pd is found.

v2: Rebase, s/ring/req
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Michel Thierry <michel.thierry@intel.com> (v1)
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

In Indirect context w/a batch buffer,
WaClearSlmSpaceAtContextSwitch

This WA performs writes to scratch page so it must be valid, this check
is performed before initializing the batch with this WA.

v2: s/PIPE_CONTROL_FLUSH_RO_CACHES/PIPE_CONTROL_FLUSH_L3 (Ville)

v3: GTT bit in scratch address should be mbz (Chris)

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Dave Gordon <david.s.gordon@intel.com>
Signed-off-by: NRafael Barbalho <rafael.barbalho@intel.com>
Signed-off-by: NArun Siluvery <arun.siluvery@linux.intel.com>
Acked-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

To initialize WA batch, at the moment we first allocate batch and then check
whether we have any WA to be initialized for the given Gen; if we don't have
any WA then we WARN the user, destroy the batch and return but this is causing
another WARN in cleanup code complaining about sleeping in atomic context.
Till we understand this better and to keep things simpler, bail out early
if we don't have WA.

Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NArun Siluvery <arun.siluvery@linux.intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Kernel 0-day framework reported warnings with WA batch patches, this patch
fixes those warnings and an additional warning reported in intel_lrc.c file.
Signed-off-by: NArun Siluvery <arun.siluvery@linux.intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

A bunch of the low level LRC functions were passing around ringbuf and ctx
pairs. In a few cases, they took the r/c pair and a request as well. This is all
quite messy and unnecesary. The context_queue() call is especially bad since the
fake request code got removed - it takes a request and three extra things that
must be extracted from the request and then it checks them against what it finds
in the request. Removing all the derivable data makes the code much simpler all
round.

This patch updates those functions to just take the request structure.

Note that logical_ring_wait_for_space now takes a request structure but already
had a local request pointer that it uses to scan for something to wait on. To
avoid confusion the local variable has been renamed 'target' (it is searching
for a target request to do something with) and the parameter has been called req
(to guarantee anything accidentally missed gets a compiler error).

v2: Updated commit message re wait_for_space (Tomas Elf review comment).

For: VIZ-5115
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Reviewed-by: NTomas Elf <tomas.elf@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The LRC submission code requires a request for tracking purposes. It does not
actually require that request to 'complete' it simply uses it for keeping hold
of reference counts on contexts and such like.

Previously, the fall back path of polling for space in the ring would start by
submitting any outstanding work that was sat in the buffer. This submission was
not done as part of the request that that work was owned by because that would
lead to complications with the request being submitted twice. Instead, a null
request structure was passed in to the submit call and a fake one was created.

That fall back path has long since been obsoleted and has now been removed. Thus
there is never any need to fake up a request structure. This patch removes that
code. A couple of sanity check warnings are added as well, just in case.

For: VIZ-5115
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Reviewed-by: NThomas Daniel <thomas.daniel@intel.com>
Reviewed-by: NTomas Elf <tomas.elf@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The outstanding_lazy_request is no longer used anywhere in the driver.
Everything that was looking at it now has a request explicitly passed in from on
high. Everything that was relying upon it behind the scenes is now explicitly
creating/passing/submitting its own private request. Thus the OLR can be
removed.

For: VIZ-5115
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Reviewed-by: NTomas Elf <tomas.elf@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Now that the *_ring_begin() functions no longer call the request allocation
code, it is finally safe for the request allocation code to call *_ring_begin().
This is important to guarantee that the space reserved for the subsequent
i915_add_request() call does actually get reserved.

v2: Renamed functions according to review feedback (Tomas Elf).

For: VIZ-5115
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Now that everything above has been converted to use requests,
intel_logical_ring_begin() can be updated to take a request instead of a
ringbuf/context pair. This also means that it no longer needs to lazily allocate
a request if no-one happens to have done it earlier.

Note that this change makes the execlist signature the same as the legacy
version. Thus the two functions could be merged into a ring->begin() wrapper if
required.

For: VIZ-5115
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Reviewed-by: NTomas Elf <tomas.elf@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Updated the ring->emit_bb_start() implementation to take a request instead of a
ringbuf/context pair.

For: VIZ-5115
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Reviewed-by: NTomas Elf <tomas.elf@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Updated the ring->emit_request() implementation to take a request instead of a
ringbuf/request pair. Also removed its use of the OLR for obtaining the
request's seqno.

For: VIZ-5115
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Reviewed-by: NTomas Elf <tomas.elf@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Updated the various ring->emit_flush() implementations to take a request instead
of a ringbuf/context pair.

For: VIZ-5115
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Reviewed-by: NTomas Elf <tomas.elf@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Updated the *_ring_flush_all_caches() functions to take requests instead of
rings or ringbuf/context pairs.

For: VIZ-5115
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Reviewed-by: NTomas Elf <tomas.elf@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Updated the *_ring_workarounds_emit() functions to take requests instead of
ring/context pairs.

For: VIZ-5115
Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
Reviewed-by: NTomas Elf <tomas.elf@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>