[PATCH] RDMA/siw: use kzalloc_flex

[Rosen Penev]

Simplifies allocations by using a flexible array member in this struct.

Add __counted_by to get extra runtime analysis.

Signed-off-by: Rosen Penev <rosenp@xxxxxxxxx>
---
 drivers/infiniband/sw/siw/siw.h     |  2 +-
 drivers/infiniband/sw/siw/siw_mem.c | 12 +++---------
 2 files changed, 4 insertions(+), 10 deletions(-)

diff --git a/drivers/infiniband/sw/siw/siw.h b/drivers/infiniband/sw/siw/siw.h
index f5fd71717b80..2b327a899a1c 100644
--- a/drivers/infiniband/sw/siw/siw.h
+++ b/drivers/infiniband/sw/siw/siw.h
@@ -119,9 +119,9 @@ struct siw_page_chunk {
 
 struct siw_umem {
 	struct ib_umem *base_mem;
-	struct siw_page_chunk *page_chunk;
 	int num_pages;
 	u64 fp_addr; /* First page base address */
+	struct siw_page_chunk page_chunk[] __counted_by(num_pages);
 };
 
 struct siw_pble {
diff --git a/drivers/infiniband/sw/siw/siw_mem.c b/drivers/infiniband/sw/siw/siw_mem.c
index 98c802b3ed72..08047fcf0df1 100644
--- a/drivers/infiniband/sw/siw/siw_mem.c
+++ b/drivers/infiniband/sw/siw/siw_mem.c
@@ -50,7 +50,6 @@ void siw_umem_release(struct siw_umem *umem)
 		kfree(umem->page_chunk[i].plist);
 		num_pages -= PAGES_PER_CHUNK;
 	}
-	kfree(umem->page_chunk);
 	kfree(umem);
 }
 
@@ -347,16 +346,12 @@ struct siw_umem *siw_umem_get(struct ib_device *base_dev, u64 start,
 	num_pages = PAGE_ALIGN(start + len - first_page_va) >> PAGE_SHIFT;
 	num_chunks = (num_pages >> CHUNK_SHIFT) + 1;
 
-	umem = kzalloc_obj(*umem);
+	umem = kzalloc_flex(*umem, page_chunk, num_chunks);
 	if (!umem)
 		return ERR_PTR(-ENOMEM);
 
-	umem->page_chunk =
-		kzalloc_objs(struct siw_page_chunk, num_chunks);
-	if (!umem->page_chunk) {
-		rv = -ENOMEM;
-		goto err_out;
-	}
+	umem->num_pages = num_pages;
+
 	base_mem = ib_umem_get(base_dev, start, len, rights);
 	if (IS_ERR(base_mem)) {
 		rv = PTR_ERR(base_mem);
@@ -385,7 +380,6 @@ struct siw_umem *siw_umem_get(struct ib_device *base_dev, u64 start,
 		umem->page_chunk[i].plist = plist;
 		while (nents--) {
 			*plist = sg_page_iter_page(&sg_iter);
-			umem->num_pages++;
 			num_pages--;
 			plist++;
 			if (!__sg_page_iter_next(&sg_iter))
-- 
2.53.0