From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Mon, 9 Sep 2019 12:00:08 +0100
Subject: drm/i915: Perform GGTT restore much earlier during resume
Git-commit: 6c76a93c453643e11a1063906c7c39168dd8d163
Patch-mainline: 5.4-rc3
No-fix: cec5ca08e36fd18d2939b98055346b3b06f56c6c
References: bnc#1151927 5.3.7

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>
Link: https://patchwork.freedesktop.org/patch/msgid/20190909110011.8958-4-chris@chris-wilson.co.uk
(cherry picked from commit cec5ca08e36fd18d2939b98055346b3b06f56c6c)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 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
@@ -2254,6 +2254,11 @@ 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->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);
 	}
 }