[RFC PATCH rdma-next 05/10] RDMA/rxe: Allow registering persistent flag for pmem MR only

[Li Zhijian]

Memory region should support 2 placement types: IB_ACCESS_FLUSH_PERSISTENT
and IB_ACCESS_FLUSH_GLOBAL_VISIBILITY, and only pmem/nvdimm has ability to
persist data(IB_ACCESS_FLUSH_PERSISTENT).

Signed-off-by: Li Zhijian <lizhijian@xxxxxxxxxxxxxx>
---
 drivers/infiniband/sw/rxe/rxe_mr.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/infiniband/sw/rxe/rxe_mr.c b/drivers/infiniband/sw/rxe/rxe_mr.c
index bcd5e7afa475..21616d058f29 100644
--- a/drivers/infiniband/sw/rxe/rxe_mr.c
+++ b/drivers/infiniband/sw/rxe/rxe_mr.c
@@ -206,6 +206,11 @@ static bool iova_in_pmem(struct rxe_mr *mr, u64 iova, int length)
 	return page_in_dev_pagemap(page);
 }
 
+static bool ib_check_flush_access_flags(struct ib_mr *mr, u32 flags)
+{
+	return mr->is_pmem || !(flags & IB_ACCESS_FLUSH_PERSISTENT);
+}
+
 int rxe_mr_init_user(struct rxe_pd *pd, u64 start, u64 length, u64 iova,
 		     int access, struct rxe_mr *mr)
 {
@@ -282,6 +287,13 @@ int rxe_mr_init_user(struct rxe_pd *pd, u64 start, u64 length, u64 iova,
 
 	// iova_in_pmem must be called after set is updated
 	mr->ibmr.is_pmem = iova_in_pmem(mr, iova, length);
+	if (!ib_check_flush_access_flags(&mr->ibmr, access)) {
+		pr_err("Cannot set IB_ACCESS_FLUSH_PERSISTENT for non-pmem memory\n");
+		mr->state = RXE_MR_STATE_INVALID;
+		mr->umem = NULL;
+		err = -EINVAL;
+		goto err_release_umem;
+	}
 
 	return 0;
 
-- 
2.31.1