drm/xe/bmg: improve cache flushing behaviour

The BSpec says that EN_L3_RW_CCS_CACHE_FLUSH must be toggled
on for manual global invalidation to take effect and actually flush
device cache, however th

drm/xe/bmg: improve cache flushing behaviour

The BSpec says that EN_L3_RW_CCS_CACHE_FLUSH must be toggled
on for manual global invalidation to take effect and actually flush
device cache, however this also turns on flushing for things like
pipecontrol, which occurs between submissions for compute/render. This
sounds like massive overkill for our needs, where we already have the
manual flushing on the display side with the global invalidation. Some
observations on BMG:

1. Disabling l2 caching for host writes and stubbing out the driver
global invalidation but keeping EN_L3_RW_CCS_CACHE_FLUSH enabled, has
no impact on wb-transient-vs-display IGT, which makes sense since the
pipecontrol is now flushing the device cache after the render copy.
Without EN_L3_RW_CCS_CACHE_FLUSH the test then fails, which is also
expected since device cache is now dirty and display engine can't see
the writes.

2. Disabling EN_L3_RW_CCS_CACHE_FLUSH, but keeping the driver global
invalidation also has no impact on wb-transient-vs-display. This
suggests that the global invalidation still works as expected and is
flushing the device cache without EN_L3_RW_CCS_CACHE_FLUSH turned on.

With that drop EN_L3_RW_CCS_CACHE_FLUSH. This helps some workloads since
we no longer flush the device cache between submissions as part of
pipecontrol.

Edit: We now also have clarification from HW side that BSpec was indeed
wrong here.

v2:
- Rebase and update commit message.

BSpec: 71718
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Vitasta Wattal <vitasta.wattal@intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Nirmoy Das <nirmoy.das@intel.com>
Reviewed-by: Nirmoy Das <nirmoy.das@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241007074541.33937-2-matthew.auld@intel.com
(cherry picked from commit 67ec9f87bd6c57db1251bb2244d242f7ca5a0b6a)
[ Fix conflict due to changed xe_mmio_write32() signature ]
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>

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drm/xe/xe2: Add performance tuning for L3 cache flushing

A recommended performance tuning for LNL related to L3 cache flushing
was recently introduced in Bspec. Implement it.

Unlike the other exist

drm/xe/xe2: Add performance tuning for L3 cache flushing

A recommended performance tuning for LNL related to L3 cache flushing
was recently introduced in Bspec. Implement it.

Unlike the other existing tuning settings, we limit this one for LNL
only, since there is no info about whether this would be applicable to
other platforms yet. In the future we can come back and use IP version
ranges if applicable.

v2:
- Fix reference to Bspec. (Sai Teja, Tejas)
- Use correct register name for "Tuning: L3 RW flush all Cache". (Sai
Teja)
- Use SCRATCH3_LBCF (with the underscore) for better readability.
v3:
- Limit setting to LNL only. (Matt)

Bspec: 72161
Cc: Sai Teja Pottumuttu <sai.teja.pottumuttu@intel.com>
Cc: Tejas Upadhyay <tejas.upadhyay@intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Gustavo Sousa <gustavo.sousa@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Tejas Upadhyay <tejas.upadhyay@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240920211459.255181-5-gustavo.sousa@intel.com
(cherry picked from commit 876253165f3eaaacacb8c8bed16a9df4b6081479)
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>

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drm/xe/xe2: Extend performance tuning to media GT

With exception of "Tuning: L3 cache - media", we are currently applying
recommended performance tuning settings only for the primary GT. Let's
also

drm/xe/xe2: Extend performance tuning to media GT

With exception of "Tuning: L3 cache - media", we are currently applying
recommended performance tuning settings only for the primary GT. Let's
also implement them for the media GT when applicable.

According to our spec, media GT registers CCCHKNREG1 and L3SQCREG* exist
only in Xe2_LPM and their offsets do not match their primary GT
counterparts. Furthermore, the range where CCCHKNREG1 belongs is not
listed as a multicast range on the media GT. As such, we need to have
Xe2_LPM-specific definitions for those registers and apply the setting
only for that specific IP.

Both Xe2_HPM and Xe2_LPM contain STATELESS_COMPRESSION_CTRL and the
offset on the media GT matches the one on the primary one. So we can
simply have a copy of "Tuning: Stateless compression control" for the
media GT.

v2:
- Fix implementation with respect to multicast vs non-multicast
registers. (Matt)
- Add missing XE2LPM_CCCHKNREG1 on second action of "Tuning:
Compression Overfetch - media".
v3:
- STATELESS_COMPRESSION_CTRL on Xe2_HPM is also a multicast register,
do not define a XE2HPM_STATELESS_COMPRESSION_CTRL register. (Tejas)

Bspec: 72161
Cc: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Tejas Upadhyay <tejas.upadhyay@intel.com>
Signed-off-by: Gustavo Sousa <gustavo.sousa@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240920211459.255181-3-gustavo.sousa@intel.com
(cherry picked from commit e1f813947ccf2326cfda4558b7d31430d7860c4b)
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>

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