RDMA/hns: Support rq record doorbell for kernel space

This patch updates to support rq record doorbell for
the kernel space.

Signed-off-by: Yixian Liu <liuyixian@huawei.com>
Signed-off-by: Lijun Ou <oulijun@huawei.com>
Signed-off-by: Wei Hu (Xavier) <xavier.huwei@huawei.com>
Signed-off-by: Shaobo Xu <xushaobo2@huawei.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/hns/hns_roce_db.c

@@ -66,3 +66,115 @@ void hns_roce_db_unmap_user(struct hns_roce_ucontext *context,
 	mutex_unlock(&context->page_mutex);
 }
 EXPORT_SYMBOL(hns_roce_db_unmap_user);
+
+static struct hns_roce_db_pgdir *hns_roce_alloc_db_pgdir(
+					struct device *dma_device)
+{
+	struct hns_roce_db_pgdir *pgdir;
+
+	pgdir = kzalloc(sizeof(*pgdir), GFP_KERNEL);
+	if (!pgdir)
+		return NULL;
+
+	bitmap_fill(pgdir->order1, HNS_ROCE_DB_PER_PAGE / 2);
+	pgdir->bits[0] = pgdir->order0;
+	pgdir->bits[1] = pgdir->order1;
+	pgdir->page = dma_alloc_coherent(dma_device, PAGE_SIZE,
+					 &pgdir->db_dma, GFP_KERNEL);
+	if (!pgdir->page) {
+		kfree(pgdir);
+		return NULL;
+	}
+
+	return pgdir;
+}
+
+static int hns_roce_alloc_db_from_pgdir(struct hns_roce_db_pgdir *pgdir,
+					struct hns_roce_db *db, int order)
+{
+	int o;
+	int i;
+
+	for (o = order; o <= 1; ++o) {
+		i = find_first_bit(pgdir->bits[o], HNS_ROCE_DB_PER_PAGE >> o);
+		if (i < HNS_ROCE_DB_PER_PAGE >> o)
+			goto found;
+	}
+
+	return -ENOMEM;
+
+found:
+	clear_bit(i, pgdir->bits[o]);
+
+	i <<= o;
+
+	if (o > order)
+		set_bit(i ^ 1, pgdir->bits[order]);
+
+	db->u.pgdir	= pgdir;
+	db->index	= i;
+	db->db_record	= pgdir->page + db->index;
+	db->dma		= pgdir->db_dma  + db->index * 4;
+	db->order	= order;
+
+	return 0;
+}
+
+int hns_roce_alloc_db(struct hns_roce_dev *hr_dev, struct hns_roce_db *db,
+		      int order)
+{
+	struct hns_roce_db_pgdir *pgdir;
+	int ret = 0;
+
+	mutex_lock(&hr_dev->pgdir_mutex);
+
+	list_for_each_entry(pgdir, &hr_dev->pgdir_list, list)
+		if (!hns_roce_alloc_db_from_pgdir(pgdir, db, order))
+			goto out;
+
+	pgdir = hns_roce_alloc_db_pgdir(hr_dev->dev);
+	if (!pgdir) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	list_add(&pgdir->list, &hr_dev->pgdir_list);
+
+	/* This should never fail -- we just allocated an empty page: */
+	WARN_ON(hns_roce_alloc_db_from_pgdir(pgdir, db, order));
+
+out:
+	mutex_unlock(&hr_dev->pgdir_mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(hns_roce_alloc_db);
+
+void hns_roce_free_db(struct hns_roce_dev *hr_dev, struct hns_roce_db *db)
+{
+	int o;
+	int i;
+
+	mutex_lock(&hr_dev->pgdir_mutex);
+
+	o = db->order;
+	i = db->index;
+
+	if (db->order == 0 && test_bit(i ^ 1, db->u.pgdir->order0)) {
+		clear_bit(i ^ 1, db->u.pgdir->order0);
+		++o;
+	}
+
+	i >>= o;
+	set_bit(i, db->u.pgdir->bits[o]);
+
+	if (bitmap_full(db->u.pgdir->order1, HNS_ROCE_DB_PER_PAGE / 2)) {
+		dma_free_coherent(hr_dev->dev, PAGE_SIZE, db->u.pgdir->page,
+				  db->u.pgdir->db_dma);
+		list_del(&db->u.pgdir->list);
+		kfree(db->u.pgdir);
+	}
+
+	mutex_unlock(&hr_dev->pgdir_mutex);
+}
+EXPORT_SYMBOL_GPL(hns_roce_free_db);

drivers/infiniband/hw/hns/hns_roce_device.h

@@ -771,6 +771,8 @@ struct hns_roce_dev {
 	spinlock_t		bt_cmd_lock;
 	struct hns_roce_ib_iboe iboe;
 
+	struct list_head        pgdir_list;
+	struct mutex            pgdir_mutex;
 	int			irq[HNS_ROCE_MAX_IRQ_NUM];
 	u8 __iomem		*reg_base;
 	struct hns_roce_caps	caps;
@@ -980,6 +982,10 @@ int hns_roce_db_map_user(struct hns_roce_ucontext *context, unsigned long virt,
 			 struct hns_roce_db *db);
 void hns_roce_db_unmap_user(struct hns_roce_ucontext *context,
 			    struct hns_roce_db *db);
+int hns_roce_alloc_db(struct hns_roce_dev *hr_dev, struct hns_roce_db *db,
+		      int order);
+void hns_roce_free_db(struct hns_roce_dev *hr_dev, struct hns_roce_db *db);
+
 void hns_roce_cq_completion(struct hns_roce_dev *hr_dev, u32 cqn);
 void hns_roce_cq_event(struct hns_roce_dev *hr_dev, u32 cqn, int event_type);
 void hns_roce_qp_event(struct hns_roce_dev *hr_dev, u32 qpn, int event_type);

drivers/infiniband/hw/hns/hns_roce_hw_v2.c

@@ -498,7 +498,6 @@ static int hns_roce_v2_post_recv(struct ib_qp *ibqp, struct ib_recv_wr *wr,
 	struct hns_roce_v2_wqe_data_seg *dseg;
 	struct hns_roce_rinl_sge *sge_list;
 	struct device *dev = hr_dev->dev;
-	struct hns_roce_v2_db rq_db;
 	unsigned long flags;
 	void *wqe = NULL;
 	int ret = 0;
@@ -564,17 +563,7 @@ out:
 		/* Memory barrier */
 		wmb();
 
-		rq_db.byte_4 = 0;
-		rq_db.parameter = 0;
-
-		roce_set_field(rq_db.byte_4, V2_DB_BYTE_4_TAG_M,
-			       V2_DB_BYTE_4_TAG_S, hr_qp->qpn);
-		roce_set_field(rq_db.byte_4, V2_DB_BYTE_4_CMD_M,
-			       V2_DB_BYTE_4_CMD_S, HNS_ROCE_V2_RQ_DB);
-		roce_set_field(rq_db.parameter, V2_DB_PARAMETER_CONS_IDX_M,
-			       V2_DB_PARAMETER_CONS_IDX_S, hr_qp->rq.head);
-
-		hns_roce_write64_k((__le32 *)&rq_db, hr_qp->rq.db_reg_l);
+		*hr_qp->rdb.db_record = hr_qp->rq.head & 0xffff;
 	}
 	spin_unlock_irqrestore(&hr_qp->rq.lock, flags);
 
@@ -3476,6 +3465,8 @@ static int hns_roce_v2_destroy_qp_common(struct hns_roce_dev *hr_dev,
 		kfree(hr_qp->sq.wrid);
 		kfree(hr_qp->rq.wrid);
 		hns_roce_buf_free(hr_dev, hr_qp->buff_size, &hr_qp->hr_buf);
+		if (hr_qp->rq.wqe_cnt)
+			hns_roce_free_db(hr_dev, &hr_qp->rdb);
 	}
 
 	if (hr_dev->caps.flags & HNS_ROCE_CAP_FLAG_RQ_INLINE) {

drivers/infiniband/hw/hns/hns_roce_main.c

@@ -665,6 +665,11 @@ static int hns_roce_setup_hca(struct hns_roce_dev *hr_dev)
 	spin_lock_init(&hr_dev->sm_lock);
 	spin_lock_init(&hr_dev->bt_cmd_lock);
 
+	if (hr_dev->caps.flags & HNS_ROCE_CAP_FLAG_RECORD_DB) {
+		INIT_LIST_HEAD(&hr_dev->pgdir_list);
+		mutex_init(&hr_dev->pgdir_mutex);
+	}
+
 	ret = hns_roce_init_uar_table(hr_dev);
 	if (ret) {
 		dev_err(dev, "Failed to initialize uar table. aborting\n");

drivers/infiniband/hw/hns/hns_roce_qp.c

@@ -652,6 +652,16 @@ static int hns_roce_create_qp_common(struct hns_roce_dev *hr_dev,
 		hr_qp->rq.db_reg_l = hr_dev->reg_base + hr_dev->odb_offset +
 				     DB_REG_OFFSET * hr_dev->priv_uar.index;
 
+		if ((hr_dev->caps.flags & HNS_ROCE_CAP_FLAG_RECORD_DB) &&
+		    hns_roce_qp_has_rq(init_attr)) {
+			ret = hns_roce_alloc_db(hr_dev, &hr_qp->rdb, 0);
+			if (ret) {
+				dev_err(dev, "rq record doorbell alloc failed!\n");
+				goto err_rq_sge_list;
+			}
+			*hr_qp->rdb.db_record = 0;
+		}
+
 		/* Allocate QP buf */
 		page_shift = PAGE_SHIFT + hr_dev->caps.mtt_buf_pg_sz;
 		if (hns_roce_buf_alloc(hr_dev, hr_qp->buff_size,
@@ -659,7 +669,7 @@ static int hns_roce_create_qp_common(struct hns_roce_dev *hr_dev,
 				       &hr_qp->hr_buf, page_shift)) {
 			dev_err(dev, "hns_roce_buf_alloc error!\n");
 			ret = -ENOMEM;
-			goto err_rq_sge_list;
+			goto err_db;
 		}
 
 		hr_qp->mtt.mtt_type = MTT_TYPE_WQE;
@@ -768,6 +778,11 @@ err_buf:
 	else
 		hns_roce_buf_free(hr_dev, hr_qp->buff_size, &hr_qp->hr_buf);
 
+err_db:
+	if (!ib_pd->uobject && hns_roce_qp_has_rq(init_attr) &&
+	    (hr_dev->caps.flags & HNS_ROCE_CAP_FLAG_RECORD_DB))
+		hns_roce_free_db(hr_dev, &hr_qp->rdb);
+
 err_rq_sge_list:
 	if (hr_dev->caps.flags & HNS_ROCE_CAP_FLAG_RQ_INLINE)
 		kfree(hr_qp->rq_inl_buf.wqe_list[0].sg_list);