RDMA/rxe: Implement flush execution in responder side

Only the requested placement types that also registered in the destination
memory region are acceptable.
Otherwise, responder will also reply NAK "Remote Access Error" if it
found a placement type violation.

We will persist data via arch_wb_cache_pmem(), which could be
architecture specific.

This commit also adds 2 helpers to update qp.resp from the incoming packet.

Link: https://lore.kernel.org/r/20221206130201.30986-8-lizhijian@fujitsu.com
Reviewed-by: Zhu Yanjun <zyjzyj2000@gmail.com>
Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

1 files changed, 36 insertions, 0 deletions

diff --git a/drivers/infiniband/sw/rxe/rxe_mr.c b/drivers/infiniband/sw/rxe/rxe_mr.c
index 81a438e5010a..072eac4b65d2 100644
--- a/drivers/infiniband/sw/rxe/rxe_mr.c
+++ b/drivers/infiniband/sw/rxe/rxe_mr.c
@@ -4,6 +4,8 @@
  * Copyright (c) 2015 System Fabric Works, Inc. All rights reserved.
  */
 
+#include <linux/libnvdimm.h>
+
 #include "rxe.h"
 #include "rxe_loc.h"
 
@@ -192,6 +194,7 @@ int rxe_mr_init_user(struct rxe_dev *rxe, u64 start, u64 length, u64 iova,
 	mr->offset = ib_umem_offset(umem);
 	mr->state = RXE_MR_STATE_VALID;
 	mr->ibmr.type = IB_MR_TYPE_USER;
+	mr->ibmr.page_size = PAGE_SIZE;
 
 	return 0;
 
@@ -295,6 +298,39 @@ out:
 	return addr;
 }
 
+int rxe_flush_pmem_iova(struct rxe_mr *mr, u64 iova, int length)
+{
+	size_t offset;
+
+	if (length == 0)
+		return 0;
+
+	if (mr->ibmr.type == IB_MR_TYPE_DMA)
+		return -EFAULT;
+
+	offset = (iova - mr->ibmr.iova + mr->offset) & mr->page_mask;
+	while (length > 0) {
+		u8 *va;
+		int bytes;
+
+		bytes = mr->ibmr.page_size - offset;
+		if (bytes > length)
+			bytes = length;
+
+		va = iova_to_vaddr(mr, iova, length);
+		if (!va)
+			return -EFAULT;
+
+		arch_wb_cache_pmem(va, bytes);
+
+		length -= bytes;
+		iova += bytes;
+		offset = 0;
+	}
+
+	return 0;
+}
+
 /* copy data from a range (vaddr, vaddr+length-1) to or from
  * a mr object starting at iova.
  */