Implement pmu support for gen2 so that one can use intel_gpu_top
on it once again.
Gen2 lacks MI_MODE/MODE_IDLE so we'll have to do a bit more work
to determine the state of the engine:
- to determine if the ring contains unconsumed data we can simply
compare RING_TAIL vs. RING_HEAD
- also check RING_HEAD vs. ACTHD to catch cases where the hardware
is still executing a batch buffer but the ring head has already
caught up with the tail. Not entirely sure if that's actually
possible or not, but maybe it can happen if the batch buffer is
initiated from the very end of the ring? But even if not strictly
necessary there's no real harm in checking anyway.
- MI_WAIT_FOR_EVENT can be detected via a dedicated bit in RING_HEAD
v2: Use genX_ prefix rarther than suffix (Jani)
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241008214349.23331-5-ville.syrjala@linux.intel.com
Acked-by: Jani Nikula <jani.nikula@intel.com>
The implementation of Wa_22011450934 introduced three new register
definitions in i915_reg.h that didn't get moved to the GT/engine
register headers when all the other registers moved; let's move them to
the appropriate headers and tidy up their definitions now for
consistency:
- STATE_ACK_DEBUG is moved to the engine register header and converted
to a parameterized definition; the workaround only needs the RCS
instance to be programmed, but there are instances on other engines
that could be used by other workarounds in the future.
- The two CULLBIT registers move to the GT register header. Since
they belong to MMIO ranges that became MCR starting with Xe_HP,
their definitions should be defined as MCR_REG() and use an Xe_HP
prefix to keep the register semantics clear.
Note that the MCR definition is just for consistency and to prevent
accidental misuse if other workarounds related to these registers show
up in the future. There's no functional change to today's driver since
the workaround that references these registers only accesses them via
MI_LRR engine instructions. Engine-initiated register accesses do not
utilize the same steering controls as CPU-initiated accesses; they
use a different steering control register (0x20CC) which is initialized
to a non-terminated DSS target by pre-OS firmware and never changed
thereafter (i915 does not touch it and userspace does not have
permission to change that register).
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Gustavo Sousa <gustavo.sousa@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230117202627.4134579-1-matthew.d.roper@intel.com
Our internal teams have identified a few additional engine registers
that are worth inspecting in error state dumps during development &
debug. Let's capture and print them as part of our error dump.
For simplicity we'll just dump these registers on gen11 and beyond.
Most of these registers have existed since earlier platforms (e.g., gen6
or gen7) but were initially introduced only for a subset of the
platforms' engines; gen11 seems to be where they became available on all
engines.
Signed-off-by: Stuart Summers <stuart.summers@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220601210646.615946-1-matthew.d.roper@intel.com
Userspace may leave predication enabled upon return from the batch
buffer, which has the consequent of preventing all operation from the
ring from being executed, including all the synchronisation, coherency
control, arbitration and user signaling. This is more than just a local
gpu hang in one client, as the user has the ability to prevent the
kernel from applying critical workarounds and can cause a full GT reset.
We could simply execute MI_SET_PREDICATE upon return from the user
batch, but this has the repercussion of modifying the user's context
state. Instead, we opt to execute a fixup batch which by mixing
predicated operations can determine the state of the
SET_PREDICATE_RESULT register and restore it prior to the next userspace
batch. This allows us to protect the kernel's ring without changing the
uABI.
Suggested-by: Zbigniew Kempczynski <zbigniew.kempczynski@intel.com>
Signed-off-by: Chris Wilson <chris.p.wilson@intel.com>
Cc: Zbigniew Kempczynski <zbigniew.kempczynski@intel.com>
Cc: Thomas Hellstrom <thomas.hellstrom@intel.com>
Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220425152317.4275-4-ramalingam.c@intel.com
These SFC registers were defined in an unusual way, taking an engine as
a parameter rather than an engine MMIO base offset. Let's adjust them
to match the style used by other per-engine registers and move them to
intel_engine_regs.h.
While doing this move, we can drop GEN12_HCP_SFC_FORCED_LOCK completely;
it was intended for use in an early version of a hardware workaround,
but was no longer necessary by the time the workaround was finalized.
It is not used anywhere in the driver.
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Matt Atwood <matthew.s.atwood@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220209051140.1599643-3-matthew.d.roper@intel.com
The various MI_PREDICATE registers have per-engine instances. Today we
only utilize the RCS0 instance of each, but that will likely change in
the future; switch to parameterized register definitions to make these
easier to work with going forward.
Of special note is MI_PREDICATE_RESULT_2; we only use it in one place in
the driver today in HSW-specific code. It turns out that the bspec
(page 94) lists two different offsets for this register on HSW; one is
in the standard location shared by all other platforms (base + 0x3bc)
and the other is an unusual location (0x2214). We're using the second,
non-standard offset in i915 today; that offset doesn't exist on any
other platforms (and it's not even 100% clear that it's correct for HSW)
so I've renamed the current non-standard definition to
HSW_MI_PREDICATE_RESULT_2; the new cross-platform parameterized macro
(which is still unused at the moment) uses the standard offset.
Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220127234334.4016964-5-matthew.d.roper@intel.com
