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| author | Ville Syrjälä <ville.syrjala@linux.intel.com> | 2024-02-02 23:43:28 +0100 |
|---|---|---|
| committer | Ville Syrjälä <ville.syrjala@linux.intel.com> | 2024-02-07 00:58:54 +0100 |
| commit | c08c364102d07288610734de34111a666e730ae7 (patch) | |
| tree | 176a8848e9cd2f401a43bf725ccdc27f1c2e81a7 /drivers/gpu/drm/i915/i915_utils.h | |
| parent | drm/i915: Remove ad-hoc lmem/stolen debugs (diff) | |
| download | linux-c08c364102d07288610734de34111a666e730ae7.tar.xz linux-c08c364102d07288610734de34111a666e730ae7.zip | |
drm/i915: Bypass LMEMBAR/GTTMMADR for MTL stolen memory access
On MTL accessing stolen memory via the BARs is somehow borked,
and it can hang the machine. As a workaround let's bypass the
BARs and just go straight to DSMBASE/GSMBASE instead.
Note that on every other platform this itself would hang the
machine, but on MTL the system firmware is expected to relax
the access permission guarding stolen memory to enable this
workaround, and thus direct CPU accesses should be fine.
The raw stolen memory areas won't be passed to VMs so we'll
need to risk using the BAR there for the initial setup. Once
command submission is up we should switch to MI_UPDATE_GTT
which at least shouldn't hang the whole machine.
v2: Don't use direct GSM/DSM access on guests
Add w/a number
v3: Check register 0x138914 to see if pcode did its job
Add some debug prints
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
Reviewed-by: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
Reviewed-by: Nirmoy Das <nirmoy.das@intel.com>
Tested-by: Paz Zcharya <pazz@chromium.org>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240202224340.30647-5-ville.syrjala@linux.intel.com
Diffstat (limited to 'drivers/gpu/drm/i915/i915_utils.h')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_utils.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_utils.h b/drivers/gpu/drm/i915/i915_utils.h index f98577967b7f..b45ef0560611 100644 --- a/drivers/gpu/drm/i915/i915_utils.h +++ b/drivers/gpu/drm/i915/i915_utils.h @@ -391,4 +391,6 @@ static inline bool i915_run_as_guest(void) bool i915_vtd_active(struct drm_i915_private *i915); +bool i915_direct_stolen_access(struct drm_i915_private *i915); + #endif /* !__I915_UTILS_H */ |