Early in the development of Xe we identified an issue with SVG state
handling on DG2 and MTL (and later on Xe2 as well). In
commit 72ac304769 ("drm/xe: Emit SVG state on RCS during driver load
on DG2 and MTL") and commit fb24b858a2 ("drm/xe/xe2: Update SVG state
handling") we implemented our own workaround to prevent SVG state from
leaking from context A to context B in cases where context B never
issues a specific state setting.
The hardware teams have now created official workaround Wa_14019789679
to cover this issue. The workaround description only requires emitting
3DSTATE_MESH_CONTROL, since they believe that's the only SVG instruction
that would potentially remain unset by a context B, but still cause
notable issues if unwanted values were inherited from context A.
However since we already have a more extensive implementation that emits
the entire SVG state and prevents _any_ SVG state from unintentionally
leaking, we'll stick with our existing implementation just to be safe.
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240812181042.2013508-2-matthew.d.roper@intel.com
The flags stored in the BO grew over time without following
much a naming pattern. First of all, get rid of the _BIT suffix that was
banned from everywhere else due to the guideline in
drivers/gpu/drm/i915/i915_reg.h that xe kind of follows:
Define bits using ``REG_BIT(N)``. Do **not** add ``_BIT`` suffix to the name.
Here the flags aren't for a register, but it's good practice to keep it
consistent.
Second divergence on names is the use or not of "CREATE". This is
because most of the flags are passed to xe_bo_create*() family of
functions, changing its behavior. However, since the flags are also
stored in the bo itself and checked elsewhere in the code, it seems
better to just omit the CREATE part.
With those 2 guidelines, all the flags are given the form
XE_BO_FLAG_<FLAG_NAME> with the following commands:
git grep -le "XE_BO_" -- drivers/gpu/drm/xe | xargs sed -i \
-e "s/XE_BO_\([_A-Z0-9]*\)_BIT/XE_BO_\1/g" \
-e 's/XE_BO_CREATE_/XE_BO_FLAG_/g'
git grep -le "XE_BO_" -- drivers/gpu/drm/xe | xargs sed -i -r \
-e 's/XE_BO_(DEFER_BACKING|SCANOUT|FIXED_PLACEMENT|PAGETABLE|NEEDS_CPU_ACCESS|NEEDS_UC|INTERNAL_TEST|INTERNAL_64K|GGTT_INVALIDATE)/XE_BO_FLAG_\1/g'
And then the defines in drivers/gpu/drm/xe/xe_bo.h are adjusted to
follow the coding style.
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240322142702.186529-3-lucas.demarchi@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Those cases missed in previous uAPI cleanups were mostly accidentally
brought in from i915 or created to exercise the possibilities of gpuvm
but they are not used by userspace yet, so let's remove them. They can
still be brought back later if needed.
v2:
- Fix XE_VM_FLAG_FAULT_MODE support in xe_lrc.c (Brian Welty)
- Leave DRM_XE_VM_BIND_OP_UNMAP_ALL (José Roberto de Souza)
- Ensure invalid flag values are rejected (Rodrigo Vivi)
v3: Rebase after removal of persistent exec_queues (Francois Dugast)
v4: Rodrigo: Rebase after the new dumpable flag.
Fixes: dd08ebf6c3 ("drm/xe: Introduce a new DRM driver for Intel GPUs")
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Francois Dugast <francois.dugast@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240222232356.175431-1-rodrigo.vivi@intel.com
After noticing in logs there were still mentions to GEN6 registers, it
was clear commit d9b79ad275 ("drm/xe: Drop gen afixes from registers")
didn't take care of all the afixes. Some were added later, but there are
also constants and strings still using that. Continue the cleanup
removing the remaining ones.
To keep it consistent with code nearby, a few other changes are made:
- Remove prefix in INTEL_LEGACY_64B_CONTEXT
- Remove GEN8_CTX_L3LLC_COHERENT since it's unused
- Rename GEN9_FREQ_SCALER to GT_FREQUENCY_SCALER
v2: Use XELP_ as prefix for NUM_MOCS_ENTRIES and remove changes to
MOCS_ENTRIES as this is now done as part of a previous commit
(Matt Roper)
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://lore.kernel.org/r/20231117174049.527192-3-lucas.demarchi@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
As with DG2/MTL, Xe2 also fails to emit instruction headers for SVG
state instructions if no explicit state has been set. The SVG part of
the LRC is nearly identical to DG2/MTL; the only change is that
3DSTATE_DRAWING_RECTANGLE has been replaced by
3DSTATE_DRAWING_RECTANGLE_FAST, so we can just re-use the same state
table and handle that single instruction when we encounter it.
Bspec: 65182
Reviewed-by: Balasubramani Vivekanandan <balasubramani.vivekanandan@intel.com>
Link: https://lore.kernel.org/r/20231025151732.3461842-8-matthew.d.roper@intel.com
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
When recording the default LRC, the expectation is that the hardware's
original state settings (both register and instruction) will be written
out to the LRC upon first context switch. For many 3DSTATE_* state
instructions that don't truly have "default" values, this translates to
a simple instruction header (opcodes + dword length) being written to
the LRC, followed by an appropriate number of blank dwords as a place
holder. When userspace creates a context (which starts as a copy of the
default LRC), they'll generally emit real 3DSTATE_* as part of their
initialization to select the settings they desire. If they don't emit
one of the 3DSTATE instructions, then the zeroed dwords that remain in
their LRC image generally translate to various state remaining disabled.
This will either be what userspace wants or will lead to very
reproducible and easily-debugged problems (rendering glitches, engine
hangs).
It turns out that a subset of the 3DSTATE instructions, specifically
those belonging to the SVG (State Variable - Global) unit, are not only
emitting 0's for the instruction's "body" dwords, but also for the
instruction header dword if no specific state has been explicitly set
before context switch. This means that when the hardware switches to a
context that hasn't explicitly provided an appropriate state setting,
the hardware will just see a sequence of NOOPs in the spot reserved for
that 3DSTATE instruction while executing the LRC, and the actual
hardware state setting will unintentionally inherit the configuration
used by the previously running context. Now when userspace makes a
mistake and forgets to emit an important state instruction they no
longer get consistent, easily-reproducible corruption/hangs, but rather
erratic behavior where the presence/absence of a problem depends on what
other workloads are running on the system and what order the contexts
are scheduled on the engine.
A specific example of this that came up recently related to mesh shading
The OpenGL driver was not specifically emitting a 3DSTATE_MESH_CONTROL
to disable mesh shading at context init, so on context switch, mesh
shading would either be on or off depending on what the previous context
had been doing. Vulkan apps _were_ enabling mesh shading, so running a
Vulkan app and then context switching to an OpenGL app resulted in mesh
shading still unexpectedly being enabled during OpenGL operation, and
since other Mesh-related state was not properly initialized for that
context a GPU hang was seen. Due to the specific ordering requirements
(Vulkan app runs first, followed by OpenGL app), it took additional
debug effort to track down the cause of the problem.
There are various workarounds related to this behavior, with current
implementations handled in the userspace drivers. E.g., Wa_14019789679
and Wa_22018402687. However it's been suggested that the kernel driver
can help simplify things here by emitting zeroed SVG state with proper
instruction headers as part of our default context creation (i.e., at
the same point we apply LRC workarounds). This will help ensure that
any future cases where a userspace driver does not emit an important
state setting will result in consistent behavior.
Bspec: 46261
Reviewed-by: Balasubramani Vivekanandan <balasubramani.vivekanandan@intel.com>
Link: https://lore.kernel.org/r/20231025151732.3461842-7-matthew.d.roper@intel.com
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
RCS and CCS engines include several non-register gfxpipe commands in
their LRC images. Include these in the dump output so that we can see
exactly what's inside the context snapshot.
v2:
- Include raw instruction header in output
- Add 3DSTATE_AMFS_TEXTURE_POINTERS and 3DSTATE_MONOFILTER_SIZE. The
first was supposed to be removed in Xe_HPG, and the second by
gen12, but both still show up in the RCS LRC.
v3:
- Sanity check that we don't have numdw > remaining_dw. (Lucas)
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://lore.kernel.org/r/20231016163449.1300701-14-matthew.d.roper@intel.com
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
For non-RCS engines, nearly all of the LRC state is composed of MI
instructions (specifically MI_LOAD_REGISTER_IMM). Providing a dump
interface allows us to verify that the context image layout matches
what's documented in the bspec, and also allows us to check whether LRC
workarounds are being properly captured by the default state we record
at startup.
For now, the non-MI instructions found in the RCS and CCS engines will
dump as "unknown;" parsing of those will be added in a follow-up patch.
v2:
- Add raw instruction header as well as decoded meaning. (Lucas)
- Check that num_dw isn't greater than remaining_dw for instructions
that have a "# dwords" field. (Lucas)
- Clarify comment about skipping over ppHWSP. (Lucas)
Bspec: 64993
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://lore.kernel.org/r/20231016163449.1300701-13-matthew.d.roper@intel.com
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Extracting the common MI_* instructions that can be used with any engine
to their own header will make it easier as we add additional engine
instructions in upcoming patches.
Also, since the majority of GPU instructions (both MI and non-MI) have
a "length" field in bits 7:0 of the instruction header, a common define
is added for that. Instruction-specific length fields are still defined
for special case instructions that have larger/smaller length fields.
v2:
- Use "instr" instead of "inst" as the short form of "instruction"
everywhere. (Lucas)
- Include xe_reg_defs.h instead of the i915 compat header. (Lucas)
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://lore.kernel.org/r/20231016163449.1300701-12-matthew.d.roper@intel.com
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
The XE_WARN_ON macro maps to WARN_ON which is not justified
in many cases where only a simple debug check is needed.
Replace the use of the XE_WARN_ON macro with the new xe_assert
macros which relies on drm_*. This takes a struct drm_device
argument, which is one of the main changes in this commit. The
other main change is that the condition is reversed, as with
XE_WARN_ON a message is displayed if the condition is true,
whereas with xe_assert it is if the condition is false.
v2:
- Rebase
- Keep WARN splats in xe_wopcm.c (Matt Roper)
v3:
- Rebase
Signed-off-by: Francois Dugast <francois.dugast@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Engine register state layout has changed a bit on Xe2. We'll also
explicitly define a BCS layout to ensure BLIT_SWCTL and BLIT_CCTL are
included.
Bspec: 65182, 60184, 55793
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Matt Atwood <matthew.s.atwood@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
The render and compute context are significantly smaller on Xe2 than on
previous platforms.
Registers:
- Render: 3008 dwords -> 12032 bytes -> round to 3 pages
- Compute: 1424 dwords -> 5696 bytes -> round to 2 pages
We also allocate one additional page for the HWSP, so the total
allocation sizes for render and compute are 4 and 3 pages respectively.
Bspec: 65182, 56578, 55793
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Matt Atwood <matthew.s.atwood@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Replace calls to XE_BUG_ON() with calls XE_WARN_ON() which in turn calls
WARN() instead of BUG(). BUG() crashes the kernel and should only be
used when it is absolutely unavoidable in case of catastrophic and
unrecoverable failures, which is not the case here.
Signed-off-by: Francois Dugast <francois.dugast@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reduce the number of warnings reported by checkpatch.pl from 118 to 48 by
addressing those warnings types:
LEADING_SPACE
LINE_SPACING
BRACES
TRAILING_SEMICOLON
CONSTANT_COMPARISON
BLOCK_COMMENT_STYLE
RETURN_VOID
ONE_SEMICOLON
SUSPECT_CODE_INDENT
LINE_CONTINUATIONS
UNNECESSARY_ELSE
UNSPECIFIED_INT
UNNECESSARY_INT
MISORDERED_TYPE
Signed-off-by: Francois Dugast <francois.dugast@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
