Revert "amdgpu: clean up non list code path for vamgr"

This reverts commit 41b94a3fb6e87d057fad78568d920d29489e5060.

It caused crashes with radeonsi in at least glxgears and Xorg.
diff --git a/amdgpu/amdgpu_vamgr.c b/amdgpu/amdgpu_vamgr.c
index 2311e5e..a2852b5 100644
--- a/amdgpu/amdgpu_vamgr.c
+++ b/amdgpu/amdgpu_vamgr.c
@@ -48,19 +48,12 @@
 drm_private void amdgpu_vamgr_init(struct amdgpu_bo_va_mgr *mgr, uint64_t start,
 				   uint64_t max, uint64_t alignment)
 {
-	struct amdgpu_bo_va_hole *n;
-
+	mgr->va_offset = start;
 	mgr->va_max = max;
 	mgr->va_alignment = alignment;
 
 	list_inithead(&mgr->va_holes);
 	pthread_mutex_init(&mgr->bo_va_mutex, NULL);
-	pthread_mutex_lock(&mgr->bo_va_mutex);
-	n = calloc(1, sizeof(struct amdgpu_bo_va_hole));
-	n->size = mgr->va_max;
-	n->offset = start;
-	list_add(&n->list, &mgr->va_holes);
-	pthread_mutex_unlock(&mgr->bo_va_mutex);
 }
 
 drm_private void amdgpu_vamgr_deinit(struct amdgpu_bo_va_mgr *mgr)
@@ -129,14 +122,41 @@
 		}
 	}
 
+	if (base_required) {
+		if (base_required < mgr->va_offset) {
+			pthread_mutex_unlock(&mgr->bo_va_mutex);
+			return AMDGPU_INVALID_VA_ADDRESS;
+		}
+		offset = mgr->va_offset;
+		waste = base_required - mgr->va_offset;
+	} else {
+		offset = mgr->va_offset;
+		waste = offset % alignment;
+		waste = waste ? alignment - waste : 0;
+	}
+
+	if (offset + waste + size > mgr->va_max) {
+		pthread_mutex_unlock(&mgr->bo_va_mutex);
+		return AMDGPU_INVALID_VA_ADDRESS;
+	}
+
+	if (waste) {
+		n = calloc(1, sizeof(struct amdgpu_bo_va_hole));
+		n->size = waste;
+		n->offset = offset;
+		list_add(&n->list, &mgr->va_holes);
+	}
+
+	offset += waste;
+	mgr->va_offset += size + waste;
 	pthread_mutex_unlock(&mgr->bo_va_mutex);
-	return AMDGPU_INVALID_VA_ADDRESS;
+	return offset;
 }
 
 static drm_private void
 amdgpu_vamgr_free_va(struct amdgpu_bo_va_mgr *mgr, uint64_t va, uint64_t size)
 {
-	struct amdgpu_bo_va_hole *hole, *next;
+	struct amdgpu_bo_va_hole *hole;
 
 	if (va == AMDGPU_INVALID_VA_ADDRESS)
 		return;
@@ -144,46 +164,61 @@
 	size = ALIGN(size, mgr->va_alignment);
 
 	pthread_mutex_lock(&mgr->bo_va_mutex);
-	hole = container_of(&mgr->va_holes, hole, list);
-	LIST_FOR_EACH_ENTRY(next, &mgr->va_holes, list) {
-		if (next->offset < va)
-			break;
-		hole = next;
-	}
-
-	if (&hole->list != &mgr->va_holes) {
-		/* Grow upper hole if it's adjacent */
-		if (hole->offset == (va + size)) {
-			hole->offset = va;
-			hole->size += size;
-			/* Merge lower hole if it's adjacent */
-			if (next != hole &&
-			    &next->list != &mgr->va_holes &&
-			    (next->offset + next->size) == va) {
-				next->size += hole->size;
+	if ((va + size) == mgr->va_offset) {
+		mgr->va_offset = va;
+		/* Delete uppermost hole if it reaches the new top */
+		if (!LIST_IS_EMPTY(&mgr->va_holes)) {
+			hole = container_of(mgr->va_holes.next, hole, list);
+			if ((hole->offset + hole->size) == va) {
+				mgr->va_offset = hole->offset;
 				list_del(&hole->list);
 				free(hole);
 			}
 		}
-	}
+	} else {
+		struct amdgpu_bo_va_hole *next;
 
-	/* Grow lower hole if it's adjacent */
-	if (next != hole && &next->list != &mgr->va_holes &&
-	    (next->offset + next->size) == va) {
-		next->size += size;
-		goto out;
-	}
+		hole = container_of(&mgr->va_holes, hole, list);
+		LIST_FOR_EACH_ENTRY(next, &mgr->va_holes, list) {
+			if (next->offset < va)
+				break;
+			hole = next;
+		}
 
-	/* FIXME on allocation failure we just lose virtual address space
-	 * maybe print a warning
-	 */
-	next = calloc(1, sizeof(struct amdgpu_bo_va_hole));
-	if (next) {
-		next->size = size;
-		next->offset = va;
-		list_add(&next->list, &hole->list);
-	}
+		if (&hole->list != &mgr->va_holes) {
+			/* Grow upper hole if it's adjacent */
+			if (hole->offset == (va + size)) {
+				hole->offset = va;
+				hole->size += size;
+				/* Merge lower hole if it's adjacent */
+				if (next != hole &&
+				    &next->list != &mgr->va_holes &&
+				    (next->offset + next->size) == va) {
+					next->size += hole->size;
+					list_del(&hole->list);
+					free(hole);
+				}
+				goto out;
+			}
+		}
 
+		/* Grow lower hole if it's adjacent */
+		if (next != hole && &next->list != &mgr->va_holes &&
+				(next->offset + next->size) == va) {
+			next->size += size;
+			goto out;
+		}
+
+		/* FIXME on allocation failure we just lose virtual address space
+		 * maybe print a warning
+		 */
+		next = calloc(1, sizeof(struct amdgpu_bo_va_hole));
+		if (next) {
+			next->size = size;
+			next->offset = va;
+			list_add(&next->list, &hole->list);
+		}
+	}
 out:
 	pthread_mutex_unlock(&mgr->bo_va_mutex);
 }