drm/i915: Remove short-term pins from execbuf, v6.

Add a flag PIN_VALIDATE, to indicate we don't need to pin and only
protected by the object lock.

This removes the need to unpin, which is done by just releasing the
lock.

eb_reserve is slightly reworked for readability, but the same steps
are still done:
- First pass pins with NONBLOCK.
- Second pass unbinds all objects first, then pins.
- Third pass is only called when not all objects are softpinned, and
  unbinds all objects, then calls i915_gem_evict_vm(), then pins.

Changes since v1:
- Split out eb_reserve() into separate functions for readability.
Changes since v2:
- Make batch buffer mappable on platforms where only GGTT is available,
  to prevent moving the batch buffer during relocations.
Changes since v3:
- Preserve current behavior for batch buffer, instead be cautious when
  calling i915_gem_object_ggtt_pin_ww, and re-use the current batch vma
  if it's inside ggtt and map-and-fenceable.
- Remove impossible condition check from eb_reserve. (Matt)
Changes since v5:
- Do not even temporarily pin, just call i915_gem_evict_vm() and mark
  all vma's as unpinned.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220114132320.109030-7-maarten.lankhorst@linux.intel.com

1 files changed, 0 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/gt/intel_ggtt_fencing.c b/drivers/gpu/drm/i915/gt/intel_ggtt_fencing.c
index beabf3bc9b75..c52d255e8ef3 100644
--- a/drivers/gpu/drm/i915/gt/intel_ggtt_fencing.c
+++ b/drivers/gpu/drm/i915/gt/intel_ggtt_fencing.c
@@ -425,7 +425,6 @@ int i915_vma_pin_fence(struct i915_vma *vma)
 	 * must keep the device awake whilst using the fence.
 	 */
 	assert_rpm_wakelock_held(vma->vm->gt->uncore->rpm);
-	GEM_BUG_ON(!i915_vma_is_pinned(vma));
 	GEM_BUG_ON(!i915_vma_is_ggtt(vma));
 
 	err = mutex_lock_interruptible(&vma->vm->mutex);