mainline  inclusion
from mainline-v5.7
commit 24c22112
category: bugfix
bugzilla: NA
CVE: NA

Encapsulate qp buffer allocation related code into 3 functions:
alloc_qp_buf(), map_wqe_buf() and free_qp_buf().

Link: https://lore.kernel.org/r/1582526258-13825-5-git-send-email-liweihang@huawei.comSigned-off-by: NXi Wang <wangxi11@huawei.com>
Signed-off-by: NWeihang Li <liweihang@huawei.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: NShunfeng Yang <yangshunfeng2@huawei.com>
Reviewed-by: Nchunzhi hu <huchunzhi@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>