From 04cacd6746ef755915bcfd77a3573987df90bf0f Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Wed, 1 Apr 2020 20:41:35 +0100
Subject: drm/i915/gem: Try allocating va from free space
Git-commit: 8a338f4bf64242e3284b4d937890aee8899500cd
Patch-mainline: v5.8-rc1
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322

If the current node/entry location is occupied, and the object is not
pinned, try assigning it some free space. We cannot wait here, so if in
doubt, we unreserve and try to grab all at once.

v2: Use the final pin_flags so that we won't have to move the object if
we find the wrong free space.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200401194135.5442-1-chris@chris-wilson.co.uk
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 .../gpu/drm/i915/gem/i915_gem_execbuffer.c    | 68 ++++++++++++-------
 1 file changed, 43 insertions(+), 25 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index 9c045a28f845..02c1f29213b6 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -429,6 +429,32 @@ eb_vma_misplaced(const struct drm_i915_gem_exec_object2 *entry,
 	return false;
 }
 
+static u64 eb_pin_flags(const struct drm_i915_gem_exec_object2 *entry,
+			unsigned int exec_flags)
+{
+	u64 pin_flags = 0;
+
+	if (exec_flags & EXEC_OBJECT_NEEDS_GTT)
+		pin_flags |= PIN_GLOBAL;
+
+	/*
+	 * Wa32bitGeneralStateOffset & Wa32bitInstructionBaseOffset,
+	 * limit address to the first 4GBs for unflagged objects.
+	 */
+	if (!(exec_flags & EXEC_OBJECT_SUPPORTS_48B_ADDRESS))
+		pin_flags |= PIN_ZONE_4G;
+
+	if (exec_flags & __EXEC_OBJECT_NEEDS_MAP)
+		pin_flags |= PIN_MAPPABLE;
+
+	if (exec_flags & EXEC_OBJECT_PINNED)
+		pin_flags |= entry->offset | PIN_OFFSET_FIXED;
+	else if (exec_flags & __EXEC_OBJECT_NEEDS_BIAS)
+		pin_flags |= BATCH_OFFSET_BIAS | PIN_OFFSET_BIAS;
+
+	return pin_flags;
+}
+
 static inline bool
 eb_pin_vma(struct i915_execbuffer *eb,
 	   const struct drm_i915_gem_exec_object2 *entry,
@@ -446,8 +472,19 @@ eb_pin_vma(struct i915_execbuffer *eb,
 	if (unlikely(ev->flags & EXEC_OBJECT_NEEDS_GTT))
 		pin_flags |= PIN_GLOBAL;
 
-	if (unlikely(i915_vma_pin(vma, 0, 0, pin_flags)))
-		return false;
+	/* Attempt to reuse the current location if available */
+	if (unlikely(i915_vma_pin(vma, 0, 0, pin_flags))) {
+		if (entry->flags & EXEC_OBJECT_PINNED)
+			return false;
+
+		/* Failing that pick any _free_ space if suitable */
+		if (unlikely(i915_vma_pin(vma,
+					  entry->pad_to_size,
+					  entry->alignment,
+					  eb_pin_flags(entry, ev->flags) |
+					  PIN_USER | PIN_NOEVICT)))
+			return false;
+	}
 
 	if (unlikely(ev->flags & EXEC_OBJECT_NEEDS_FENCE)) {
 		if (unlikely(i915_vma_pin_fence(vma))) {
@@ -588,28 +625,9 @@ static int eb_reserve_vma(const struct i915_execbuffer *eb,
 			  u64 pin_flags)
 {
 	struct drm_i915_gem_exec_object2 *entry = ev->exec;
-	unsigned int exec_flags = ev->flags;
 	struct i915_vma *vma = ev->vma;
 	int err;
 
-	if (exec_flags & EXEC_OBJECT_NEEDS_GTT)
-		pin_flags |= PIN_GLOBAL;
-
-	/*
-	 * Wa32bitGeneralStateOffset & Wa32bitInstructionBaseOffset,
-	 * limit address to the first 4GBs for unflagged objects.
-	 */
-	if (!(exec_flags & EXEC_OBJECT_SUPPORTS_48B_ADDRESS))
-		pin_flags |= PIN_ZONE_4G;
-
-	if (exec_flags & __EXEC_OBJECT_NEEDS_MAP)
-		pin_flags |= PIN_MAPPABLE;
-
-	if (exec_flags & EXEC_OBJECT_PINNED)
-		pin_flags |= entry->offset | PIN_OFFSET_FIXED;
-	else if (exec_flags & __EXEC_OBJECT_NEEDS_BIAS)
-		pin_flags |= BATCH_OFFSET_BIAS | PIN_OFFSET_BIAS;
-
 	if (drm_mm_node_allocated(&vma->node) &&
 	    eb_vma_misplaced(entry, vma, ev->flags)) {
 		err = i915_vma_unbind(vma);
@@ -619,7 +637,7 @@ static int eb_reserve_vma(const struct i915_execbuffer *eb,
 
 	err = i915_vma_pin(vma,
 			   entry->pad_to_size, entry->alignment,
-			   pin_flags);
+			   eb_pin_flags(entry, ev->flags) | pin_flags);
 	if (err)
 		return err;
 
@@ -628,7 +646,7 @@ static int eb_reserve_vma(const struct i915_execbuffer *eb,
 		eb->args->flags |= __EXEC_HAS_RELOC;
 	}
 
-	if (unlikely(exec_flags & EXEC_OBJECT_NEEDS_FENCE)) {
+	if (unlikely(ev->flags & EXEC_OBJECT_NEEDS_FENCE)) {
 		err = i915_vma_pin_fence(vma);
 		if (unlikely(err)) {
 			i915_vma_unpin(vma);
@@ -636,10 +654,10 @@ static int eb_reserve_vma(const struct i915_execbuffer *eb,
 		}
 
 		if (vma->fence)
-			exec_flags |= __EXEC_OBJECT_HAS_FENCE;
+			ev->flags |= __EXEC_OBJECT_HAS_FENCE;
 	}
 
-	ev->flags = exec_flags | __EXEC_OBJECT_HAS_PIN;
+	ev->flags |= __EXEC_OBJECT_HAS_PIN;
 	GEM_BUG_ON(eb_vma_misplaced(entry, vma, ev->flags));
 
 	return 0;
-- 
2.28.0