[PATCH v4 2/3] Manually revert "drm/i915: Fix a VMA UAF for multi-gt platform"

[Janusz Krzysztofik]

This reverts changes introduced by commit f56fe3e91787, obsoleted by
"drm/i915/vma: Fix UAF on destroy against retire race".

Signed-off-by: Janusz Krzysztofik <janusz.krzyszto...@linux.intel.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c | 17 -----------------
 1 file changed, 17 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c 
b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index d3a771afb083e..cedca8fd8754d 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -2686,7 +2686,6 @@ static int
 eb_select_engine(struct i915_execbuffer *eb)
 {
        struct intel_context *ce, *child;
-       struct intel_gt *gt;
        unsigned int idx;
        int err;
 
@@ -2710,17 +2709,10 @@ eb_select_engine(struct i915_execbuffer *eb)
                }
        }
        eb->num_batches = ce->parallel.number_children + 1;
-       gt = ce->engine->gt;
 
        for_each_child(ce, child)
                intel_context_get(child);
        eb->wakeref = intel_gt_pm_get(ce->engine->gt);
-       /*
-        * Keep GT0 active on MTL so that i915_vma_parked() doesn't
-        * free VMAs while execbuf ioctl is validating VMAs.
-        */
-       if (gt->info.id)
-               eb->wakeref_gt0 = intel_gt_pm_get(to_gt(gt->i915));
 
        if (!test_bit(CONTEXT_ALLOC_BIT, &ce->flags)) {
                err = intel_context_alloc_state(ce);
@@ -2759,9 +2751,6 @@ eb_select_engine(struct i915_execbuffer *eb)
        return err;
 
 err:
-       if (gt->info.id)
-               intel_gt_pm_put(to_gt(gt->i915), eb->wakeref_gt0);
-
        intel_gt_pm_put(ce->engine->gt, eb->wakeref);
        for_each_child(ce, child)
                intel_context_put(child);
@@ -2775,12 +2764,6 @@ eb_put_engine(struct i915_execbuffer *eb)
        struct intel_context *child;
 
        i915_vm_put(eb->context->vm);
-       /*
-        * This works in conjunction with eb_select_engine() to prevent
-        * i915_vma_parked() from interfering while execbuf validates vmas.
-        */
-       if (eb->gt->info.id)
-               intel_gt_pm_put(to_gt(eb->gt->i915), eb->wakeref_gt0);
        intel_gt_pm_put(eb->context->engine->gt, eb->wakeref);
        for_each_child(eb->context, child)
                intel_context_put(child);
-- 
2.43.0