IB: Refactor umem to use linear SG table

This patch refactors the IB core umem code and vendor drivers to use a
linear (chained) SG table instead of chunk list.  With this change the
relevant code becomes clearer—no need for nested loops to build and
use umem.

Signed-off-by: Shachar Raindel <raindel@mellanox.com>
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

1 files changed, 3 insertions, 8 deletions

diff --git a/include/rdma/ib_umem.h b/include/rdma/ib_umem.h
index 9ee0d2e51b16..1ea0b65c4cfb 100644
--- a/include/rdma/ib_umem.h
+++ b/include/rdma/ib_umem.h
@@ -46,17 +46,12 @@ struct ib_umem {
         int                     page_size;
         int                     writable;
         int                     hugetlb;
-        struct list_head        chunk_list;
         struct work_struct      work;
         struct mm_struct       *mm;
         unsigned long           diff;
-};
-
-struct ib_umem_chunk {
-        struct list_head        list;
-        int                     nents;
-        int                     nmap;
-        struct scatterlist      page_list[0];
+        struct sg_table sg_head;
+        int             nmap;
+        int             npages;
 };
 
 #ifdef CONFIG_INFINIBAND_USER_MEM