Chris Wilson chris@chris-wilson.co.uk writes:

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 chris@chris-wilson.co.uk Cc: Mika Kuoppala mika.kuoppala@linux.intel.com Cc: Martin Peres martin.peres@linux.intel.com Cc: Joonas Lahtinen joonas.lahtinen@linux.intel.com Cc: stable@vger.kernel.org

Reviewed-by: Mika Kuoppala mika.kuoppala@linux.intel.com

---

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(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_pm.c b/drivers/gpu/drm/i915/gem/i915_gem_pm.c index b3993d24b83d..9b1129aaacfe 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_pm.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_pm.c @@ -242,9 +242,6 @@ void i915_gem_resume(struct drm_i915_private *i915) 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;

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c index 7b2c81a8bbaa..1af4eba968c0 100644 --- a/drivers/gpu/drm/i915/i915_drv.c +++ b/drivers/gpu/drm/i915/i915_drv.c @@ -1877,6 +1877,11 @@ static int i915_drm_resume(struct drm_device *dev) 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); diff --git a/drivers/gpu/drm/i915/selftests/i915_gem.c b/drivers/gpu/drm/i915/selftests/i915_gem.c index bb6dd54a6ff3..37593831b539 100644 --- a/drivers/gpu/drm/i915/selftests/i915_gem.c +++ b/drivers/gpu/drm/i915/selftests/i915_gem.c @@ -118,6 +118,12 @@ static void pm_resume(struct drm_i915_private *i915) with_intel_runtime_pm(&i915->runtime_pm, wakeref) { intel_gt_sanitize(&i915->gt, 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); }

}

2.23.0