From: Chris Wilson <[email protected]>

commit 6c76a93c453643e11a1063906c7c39168dd8d163 upstream.

As soon as we re-enable the various functions within the HW, they may go
off and read data via a GGTT offset. Hence, if we have not yet restored
the GGTT PTE before then, they may read and even *write* random locations
in memory.

Detected by DMAR faults during resume.

Signed-off-by: Chris Wilson <[email protected]>
Cc: Mika Kuoppala <[email protected]>
Cc: Martin Peres <[email protected]>
Cc: Joonas Lahtinen <[email protected]>
Cc: [email protected]
Reviewed-by: Mika Kuoppala <[email protected]>
Link: 
https://patchwork.freedesktop.org/patch/msgid/[email protected]
(cherry picked from commit cec5ca08e36fd18d2939b98055346b3b06f56c6c)
Signed-off-by: Rodrigo Vivi <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
 drivers/gpu/drm/i915/gem/i915_gem_pm.c    |    3 ---
 drivers/gpu/drm/i915/i915_drv.c           |    5 +++++
 drivers/gpu/drm/i915/selftests/i915_gem.c |    6 ++++++
 3 files changed, 11 insertions(+), 3 deletions(-)

--- a/drivers/gpu/drm/i915/gem/i915_gem_pm.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_pm.c
@@ -250,9 +250,6 @@ void i915_gem_resume(struct drm_i915_pri
        mutex_lock(&i915->drm.struct_mutex);
        intel_uncore_forcewake_get(&i915->uncore, FORCEWAKE_ALL);
 
-       i915_gem_restore_gtt_mappings(i915);
-       i915_gem_restore_fences(i915);
-
        if (i915_gem_init_hw(i915))
                goto err_wedged;
 
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -2238,6 +2238,11 @@ static int i915_drm_resume(struct drm_de
        if (ret)
                DRM_ERROR("failed to re-enable GGTT\n");
 
+       mutex_lock(&dev_priv->drm.struct_mutex);
+       i915_gem_restore_gtt_mappings(dev_priv);
+       i915_gem_restore_fences(dev_priv);
+       mutex_unlock(&dev_priv->drm.struct_mutex);
+
        intel_csr_ucode_resume(dev_priv);
 
        i915_restore_state(dev_priv);
--- a/drivers/gpu/drm/i915/selftests/i915_gem.c
+++ b/drivers/gpu/drm/i915/selftests/i915_gem.c
@@ -117,6 +117,12 @@ static void pm_resume(struct drm_i915_pr
        with_intel_runtime_pm(&i915->runtime_pm, wakeref) {
                intel_gt_sanitize(i915, false);
                i915_gem_sanitize(i915);
+
+               mutex_lock(&i915->drm.struct_mutex);
+               i915_gem_restore_gtt_mappings(i915);
+               i915_gem_restore_fences(i915);
+               mutex_unlock(&i915->drm.struct_mutex);
+
                i915_gem_resume(i915);
        }
 }


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