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RDMA/hns: drop dead empty check in setup_root_hem()

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setup_root_hem() reads the first entry of head->root and checks
the returned pointer against NULL:

    root_hem = list_first_entry(&head->root,
                                struct hns_roce_hem_item, list);
    if (!root_hem)
        return -ENOMEM;

list_first_entry() never returns NULL. On an empty list it returns
container_of(head, ..., list), a non-NULL garbage pointer that
aliases the head. So the check is dead.

The only caller adds an entry to head.root right before invoking
setup_root_hem():

    list_add(&root_hem->list, &head.root);
    ret = setup_root_hem(..., &head, ...);

So head.root is guaranteed non-empty on entry. Drop the check.

Link: https://patch.msgid.link/r/20260526054653.2054800-1-maoyixie.tju@gmail.com
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Maoyi Xie <maoyixie.tju@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
This commit is contained in:
Maoyi Xie 2026-05-26 13:46:53 +08:00 committed by Jason Gunthorpe
parent d6ab440240
commit ba7c4912f7
1 changed files with 0 additions and 2 deletions
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2
drivers/infiniband/hw/hns/hns_roce_hem.c
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@ -1269,8 +1269,6 @@ setup_root_hem(struct hns_roce_dev *hr_dev, struct hns_roce_hem_list *hem_list,
root_hem = list_first_entry(&head->root,
struct hns_roce_hem_item, list);
if (!root_hem)
return -ENOMEM;
total = 0;
for (i = 0; i < region_cnt && total <= max_ba_num; i++) {