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, 1 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.h b/drivers/gpu/drm/i915/i915_gem_gtt.h
index e4938aba3fe9..8c2f57eb5dda 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.h
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.h
@@ -44,6 +44,7 @@ int i915_gem_gtt_insert(struct i915_address_space *vm,
 #define PIN_HIGH		BIT_ULL(5)
 #define PIN_OFFSET_BIAS		BIT_ULL(6)
 #define PIN_OFFSET_FIXED	BIT_ULL(7)
+#define PIN_VALIDATE		BIT_ULL(8) /* validate placement only, no need to call unpin() */
 
 #define PIN_GLOBAL		BIT_ULL(10) /* I915_VMA_GLOBAL_BIND */
 #define PIN_USER		BIT_ULL(11) /* I915_VMA_LOCAL_BIND */