FAILED: patch "[PATCH] drm/i915: Fix mismatch between misplaced vma check and vma" failed to apply to 4.14-stable tree

The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 0e53656ad8abc99e0a80c3de611e593ebbf55829 Mon Sep 17 00:00:00 2001
From: Chris Wilson <[email protected]>
Date: Wed, 16 Dec 2020 09:29:51 +0000
Subject: [PATCH] drm/i915: Fix mismatch between misplaced vma check and vma
insert

When inserting a VMA, we restrict the placement to the low 4G unless the caller opts into using the full range. This was done to allow usersapce the opportunity to transition slowly from a 32b address space, and to avoid breaking inherent 32b assumptions of some commands.

However, for insert we limited ourselves to 4G-4K, but on verification we allowed the full 4G. This causes some attempts to bind a new buffer to sporadically fail with -ENOSPC, but at other times be bound successfully.

commit 48ea1e32c39d ("drm/i915/gen9: Set PIN_ZONE_4G end to 4GB - 1 page") suggests that there is a genuine problem with stateless addressing that cannot utilize the last page in 4G and so we purposefully excluded it. This means that the quick pin pass may cause us to utilize a buggy placement.

Testcase: igt/gem_exec_params/larger-than-life-batch

index b07dc1156a0e..bcc80f428172 100644
@@ -382,7 +382,7 @@ eb_vma_misplaced(const struct drm_i915_gem_exec_object2 *entry,
 		return true;
 
 	if (!(flags & EXEC_OBJECT_SUPPORTS_48B_ADDRESS) &&
-	    (vma->node.start + vma->node.size - 1) >> 32)
+	    (vma->node.start + vma->node.size + 4095) >> 32)
 		return true;
 
 	if (flags & __EXEC_OBJECT_NEEDS_MAP &&