RDMA/erdma: Refactor the storage structure of MTT entries

Currently our MTT only support inline mtt entries (0 level MTT) and
indirect MTT entries (1 level mtt), which will limit the maximum length
of MRs. In order to implement a multi-level MTT, we refactor the
structure of MTT first.
Signed-off-by: Cheng Xu <chengyou@linux.alibaba.com>
Link: https://lore.kernel.org/r/20230817102151.75964-3-chengyou@linux.alibaba.comSigned-off-by: Leon Romanovsky <leon@kernel.org>

drivers/infiniband/hw/erdma/erdma_hw.h

@@ -228,7 +228,7 @@ struct erdma_cmdq_ext_db_req {
 
 /* create_cq cfg1 */
 #define ERDMA_CMD_CREATE_CQ_MTT_CNT_MASK GENMASK(31, 16)
-#define ERDMA_CMD_CREATE_CQ_MTT_TYPE_MASK BIT(15)
+#define ERDMA_CMD_CREATE_CQ_MTT_LEVEL_MASK BIT(15)
 #define ERDMA_CMD_CREATE_CQ_MTT_DB_CFG_MASK BIT(11)
 #define ERDMA_CMD_CREATE_CQ_EQN_MASK GENMASK(9, 0)
 
@@ -258,7 +258,7 @@ struct erdma_cmdq_create_cq_req {
 
 /* regmr cfg2 */
 #define ERDMA_CMD_REGMR_PAGESIZE_MASK GENMASK(31, 27)
-#define ERDMA_CMD_REGMR_MTT_TYPE_MASK GENMASK(21, 20)
+#define ERDMA_CMD_REGMR_MTT_LEVEL_MASK GENMASK(21, 20)
 #define ERDMA_CMD_REGMR_MTT_CNT_MASK GENMASK(19, 0)
 
 struct erdma_cmdq_reg_mr_req {

drivers/infiniband/hw/erdma/erdma_qp.c

@@ -410,7 +410,7 @@ static int erdma_push_one_sqe(struct erdma_qp *qp, u16 *pi,
 			/* Copy SGLs to SQE content to accelerate */
 			memcpy(get_queue_entry(qp->kern_qp.sq_buf, idx + 1,
 					       qp->attrs.sq_size, SQEBB_SHIFT),
-			       mr->mem.mtt_buf, MTT_SIZE(mr->mem.mtt_nents));
+			       mr->mem.mtt->buf, MTT_SIZE(mr->mem.mtt_nents));
 			wqe_size = sizeof(struct erdma_reg_mr_sqe) +
 				   MTT_SIZE(mr->mem.mtt_nents);
 		} else {

drivers/infiniband/hw/erdma/erdma_verbs.h

@@ -65,7 +65,7 @@ struct erdma_pd {
  * MemoryRegion definition.
  */
 #define ERDMA_MAX_INLINE_MTT_ENTRIES 4
-#define MTT_SIZE(mtt_cnt) (mtt_cnt << 3) /* per mtt entry takes 8 Bytes. */
+#define MTT_SIZE(mtt_cnt) ((mtt_cnt) << 3) /* per mtt entry takes 8 Bytes. */
 #define ERDMA_MR_MAX_MTT_CNT 524288
 #define ERDMA_MTT_ENTRY_SIZE 8
 
@@ -90,10 +90,28 @@ static inline u8 to_erdma_access_flags(int access)
 	       (access & IB_ACCESS_REMOTE_ATOMIC ? ERDMA_MR_ACC_RA : 0);
 }
 
+/* Hierarchical storage structure for MTT entries */
+struct erdma_mtt {
+	u64 *buf;
+	size_t size;
+
+	bool continuous;
+	union {
+		dma_addr_t buf_dma;
+		struct {
+			struct scatterlist *sglist;
+			u32 nsg;
+			u32 level;
+		};
+	};
+
+	struct erdma_mtt *low_level;
+};
+
 struct erdma_mem {
 	struct ib_umem *umem;
-	void *mtt_buf;
-	u32 mtt_type;
+	struct erdma_mtt *mtt;
+
 	u32 page_size;
 	u32 page_offset;
 	u32 page_cnt;
@@ -101,8 +119,6 @@ struct erdma_mem {
 
 	u64 va;
 	u64 len;
-
-	u64 mtt_entry[ERDMA_MAX_INLINE_MTT_ENTRIES];
 };
 
 struct erdma_mr {