From: Lijun Ou <oulijun@huawei.com>
Date: Sun, 7 Apr 2019 13:23:38 +0800
Subject: RDMA/hns: Fix bug that caused srq creation to fail
Patch-mainline: v5.1-rc5
Git-commit: 4772e03d239484f3461e33c79d721c8ea03f7416
References: bsc#1104427 FATE#326416

Due to the incorrect use of the seg and obj information, the position of
the mtt is calculated incorrectly, and the free space of the page is not
enough to store the entire mtt, resulting in access to the next page. This
patch fixes this problem.

 Unable to handle kernel paging request at virtual address ffff00006e3cd000
 ...
 Call trace:
  hns_roce_write_mtt+0x154/0x2f0 [hns_roce]
  hns_roce_buf_write_mtt+0xa8/0xd8 [hns_roce]
  hns_roce_create_srq+0x74c/0x808 [hns_roce]
  ib_create_srq+0x28/0xc8

Fixes: 0203b14c4f32 ("RDMA/hns: Unify the calculation for hem index in hip08")
Signed-off-by: chenglang <chenglang@huawei.com>
Signed-off-by: Lijun Ou <oulijun@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/infiniband/hw/hns/hns_roce_hem.c |    6 ++++--
 drivers/infiniband/hw/hns/hns_roce_mr.c  |    4 ++--
 2 files changed, 6 insertions(+), 4 deletions(-)

--- a/drivers/infiniband/hw/hns/hns_roce_hem.c
+++ b/drivers/infiniband/hw/hns/hns_roce_hem.c
@@ -742,6 +742,8 @@ void *hns_roce_table_find(struct hns_roc
 		idx_offset = (obj & (table->num_obj - 1)) % obj_per_chunk;
 		dma_offset = offset = idx_offset * table->obj_size;
 	} else {
+		u32 seg_size = 64; /* 8 bytes per BA and 8 BA per segment */
+
 		hns_roce_calc_hem_mhop(hr_dev, table, &mhop_obj, &mhop);
 		/* mtt mhop */
 		i = mhop.l0_idx;
@@ -753,8 +755,8 @@ void *hns_roce_table_find(struct hns_roc
 			hem_idx = i;
 
 		hem = table->hem[hem_idx];
-		dma_offset = offset = (obj & (table->num_obj - 1)) *
-				       table->obj_size % mhop.bt_chunk_size;
+		dma_offset = offset = (obj & (table->num_obj - 1)) * seg_size %
+				       mhop.bt_chunk_size;
 		if (mhop.hop_num == 2)
 			dma_offset = offset = 0;
 	}
--- a/drivers/infiniband/hw/hns/hns_roce_mr.c
+++ b/drivers/infiniband/hw/hns/hns_roce_mr.c
@@ -707,7 +707,6 @@ static int hns_roce_write_mtt_chunk(stru
 	struct hns_roce_hem_table *table;
 	dma_addr_t dma_handle;
 	__le64 *mtts;
-	u32 s = start_index * sizeof(u64);
 	u32 bt_page_size;
 	u32 i;
 
@@ -730,7 +729,8 @@ static int hns_roce_write_mtt_chunk(stru
 		return -EINVAL;
 
 	mtts = hns_roce_table_find(hr_dev, table,
-				mtt->first_seg + s / hr_dev->caps.mtt_entry_sz,
+				mtt->first_seg +
+				start_index / HNS_ROCE_MTT_ENTRY_PER_SEG,
 				&dma_handle);
 	if (!mtts)
 		return -ENOMEM;