drm/i915: Mark shadow batch buffers as purgeable

By adding a new exec_entry flag, we cleanly mark the shadow objects
as purgeable after they are on the active list.

v2:
- Move 'shadow_batch_obj->madv = I915_MADV_WILLNEED' inside _get
  fnc (danvet, from v4 6/7 feedback)

v3:
- Remove duplicate 'madv = I915_MADV_WILLNEED' (danvet, from v6 4/5)

Issue: VIZ-4719
Signed-off-by: Brad Volkin <bradley.d.volkin@intel.com>
Reviewed-By: Jon Bloomfield <jon.bloomfield@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 8 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index 5973e2005e89..86de3720527b 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -37,6 +37,7 @@
 #define  __EXEC_OBJECT_HAS_FENCE (1<<30)
 #define  __EXEC_OBJECT_NEEDS_MAP (1<<29)
 #define  __EXEC_OBJECT_NEEDS_BIAS (1<<28)
+#define  __EXEC_OBJECT_PURGEABLE (1<<27)
 
 #define BATCH_OFFSET_BIAS (256*1024)
 
@@ -226,7 +227,12 @@ i915_gem_execbuffer_unreserve_vma(struct i915_vma *vma)
         if (entry->flags & __EXEC_OBJECT_HAS_PIN)
                 vma->pin_count--;
 
-        entry->flags &= ~(__EXEC_OBJECT_HAS_FENCE | __EXEC_OBJECT_HAS_PIN);
+        if (entry->flags & __EXEC_OBJECT_PURGEABLE)
+                obj->madv = I915_MADV_DONTNEED;
+
+        entry->flags &= ~(__EXEC_OBJECT_HAS_FENCE |
+                          __EXEC_OBJECT_HAS_PIN |
+                          __EXEC_OBJECT_PURGEABLE);
 }
 
 static void eb_destroy(struct eb_vmas *eb)
@@ -1436,6 +1442,7 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
 
                         vma = i915_gem_obj_to_ggtt(shadow_batch_obj);
                         vma->exec_entry = &shadow_exec_entry;
+                        vma->exec_entry->flags = __EXEC_OBJECT_PURGEABLE;
                         drm_gem_object_reference(&shadow_batch_obj->base);
                         list_add_tail(&vma->exec_list, &eb->vmas);