RDMA/hns: Simplify 'struct hns_roce_hem' allocation

'struct hns_roce_hem' is used to refer to the last level of
dma buffer managed by the hw, pointed by a single BA(base
address) in the previous level of BT(base table), so the dma
buffer in 'struct hns_roce_hem' must be contiguous.

Right now the size of dma buffer in 'struct hns_roce_hem' is
decided by mhop->buf_chunk_size in get_hem_table_config(),
which ensure the mhop->buf_chunk_size is power of two of
PAGE_SIZE, so there will be only one contiguous dma buffer
allocated in hns_roce_alloc_hem(), which means hem->chunk_list
and chunk->mem for linking multi dma buffers is unnecessary.

This patch removes the hem->chunk_list and chunk->mem and other
related macro and function accordingly.

Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: Junxian Huang <huangjunxian6@hisilicon.com>
Link: https://lore.kernel.org/r/20240113085935.2838701-7-huangjunxian6@hisilicon.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>

1 files changed, 3 insertions, 53 deletions

diff --git a/drivers/infiniband/hw/hns/hns_roce_hem.h b/drivers/infiniband/hw/hns/hns_roce_hem.h
index 7d23d3c51da4..6fb51db9682b 100644
--- a/drivers/infiniband/hw/hns/hns_roce_hem.h
+++ b/drivers/infiniband/hw/hns/hns_roce_hem.h
@@ -56,10 +56,6 @@ enum {
 	HEM_TYPE_TRRL,
 };
 
-#define HNS_ROCE_HEM_CHUNK_LEN	\
-	 ((256 - sizeof(struct list_head) - 2 * sizeof(int)) /	 \
-	 (sizeof(struct scatterlist) + sizeof(void *)))
-
 #define check_whether_bt_num_3(type, hop_num) \
 	(type < HEM_TYPE_MTT && hop_num == 2)
 
@@ -72,25 +68,13 @@ enum {
 	(type >= HEM_TYPE_MTT && hop_num == 1) || \
 	(type >= HEM_TYPE_MTT && hop_num == HNS_ROCE_HOP_NUM_0))
 
-struct hns_roce_hem_chunk {
-	struct list_head	 list;
-	int			 npages;
-	int			 nsg;
-	struct scatterlist	 mem[HNS_ROCE_HEM_CHUNK_LEN];
-	void			 *buf[HNS_ROCE_HEM_CHUNK_LEN];
-};
-
 struct hns_roce_hem {
-	struct list_head chunk_list;
+	void *buf;
+	dma_addr_t dma;
+	unsigned long size;
 	refcount_t refcount;
 };
 
-struct hns_roce_hem_iter {
-	struct hns_roce_hem		 *hem;
-	struct hns_roce_hem_chunk	 *chunk;
-	int				 page_idx;
-};
-
 struct hns_roce_hem_mhop {
 	u32	hop_num;
 	u32	buf_chunk_size;
@@ -133,38 +117,4 @@ void *hns_roce_hem_list_find_mtt(struct hns_roce_dev *hr_dev,
 				 struct hns_roce_hem_list *hem_list,
 				 int offset, int *mtt_cnt);
 
-static inline void hns_roce_hem_first(struct hns_roce_hem *hem,
-				      struct hns_roce_hem_iter *iter)
-{
-	iter->hem = hem;
-	iter->chunk = list_empty(&hem->chunk_list) ? NULL :
-				 list_entry(hem->chunk_list.next,
-					    struct hns_roce_hem_chunk, list);
-	iter->page_idx = 0;
-}
-
-static inline int hns_roce_hem_last(struct hns_roce_hem_iter *iter)
-{
-	return !iter->chunk;
-}
-
-static inline void hns_roce_hem_next(struct hns_roce_hem_iter *iter)
-{
-	if (++iter->page_idx >= iter->chunk->nsg) {
-		if (iter->chunk->list.next == &iter->hem->chunk_list) {
-			iter->chunk = NULL;
-			return;
-		}
-
-		iter->chunk = list_entry(iter->chunk->list.next,
-					 struct hns_roce_hem_chunk, list);
-		iter->page_idx = 0;
-	}
-}
-
-static inline dma_addr_t hns_roce_hem_addr(struct hns_roce_hem_iter *iter)
-{
-	return sg_dma_address(&iter->chunk->mem[iter->page_idx]);
-}
-
 #endif /* _HNS_ROCE_HEM_H */