From 6c76a93c453643e11a1063906c7c39168dd8d163 Mon Sep 17 00:00:00 2001

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: v5.4-rc3

References: bsc#1152489

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>

Acked-by: Thomas Zimmermann <tzimmermann@suse.de>

---

 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 92e53c25424c..ad2a63dbcac2 100644

--- a/drivers/gpu/drm/i915/gem/i915_gem_pm.c

+++ b/drivers/gpu/drm/i915/gem/i915_gem_pm.c

@@ -241,9 +241,6 @@ 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 020696726f9e..bb6f86c7067a 100644

--- a/drivers/gpu/drm/i915/i915_drv.c

+++ b/drivers/gpu/drm/i915/i915_drv.c

@@ -1924,6 +1924,11 @@ 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);

 	}

 }

-- 

2.28.0