drm/i915: Perform GGTT restore much earlier during resume

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

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_pm.c b/drivers/gpu/drm/i915/gem/i915_gem_pm.c
index b3993d24b83dbcc34ab7ad5ee83de5ac5b8d4667..9b1129aaacfe57cca76eac6289eaccb09d090424 100644 (file)
--- 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 63e52e15341432256ed8192b418cf68f9b5134a6..0aadff9b8c88e8ad5ed7f38923a3c10a7f420803 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1914,6 +1914,11 @@ 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 bb6dd54a6ff3ed1e8201114e1a2f857f9f9e1ba1..37593831b539495473c666f5f1e06875879b00fd 100644 (file)
--- 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);
        }
 }