[PATCH sched_ext/for-6.19] sched_ext: Move __SCX_DSQ_ITER_ALL_FLAGS BUILD_BUG_ON to the right place

[Tejun Heo <tj@kernel.org>]

The BUILD_BUG_ON() which checks that __SCX_DSQ_ITER_ALL_FLAGS doesn't
overlap with the private lnode bits was in scx_task_iter_start() which has
nothing to do with DSQ iteration. Move it to bpf_iter_scx_dsq_new() where it
belongs.

No functional changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
---
 kernel/sched/ext.c |    5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

--- a/kernel/sched/ext.c
+++ b/kernel/sched/ext.c
@@ -474,9 +474,6 @@ struct scx_task_iter {
  */
 static void scx_task_iter_start(struct scx_task_iter *iter)
 {
-	BUILD_BUG_ON(__SCX_DSQ_ITER_ALL_FLAGS &
-		     ((1U << __SCX_DSQ_LNODE_PRIV_SHIFT) - 1));
-
 	spin_lock_irq(&scx_tasks_lock);

 	iter->cursor = (struct sched_ext_entity){ .flags = SCX_TASK_CURSOR };
@@ -6218,6 +6215,8 @@ __bpf_kfunc int bpf_iter_scx_dsq_new(str
 		     sizeof(struct bpf_iter_scx_dsq));
 	BUILD_BUG_ON(__alignof__(struct bpf_iter_scx_dsq_kern) !=
 		     __alignof__(struct bpf_iter_scx_dsq));
+	BUILD_BUG_ON(__SCX_DSQ_ITER_ALL_FLAGS &
+		     ((1U << __SCX_DSQ_LNODE_PRIV_SHIFT) - 1));

 	/*
 	 * next() and destroy() will be called regardless of the return value.