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>

1 files changed, 112 insertions, 0 deletions

diff --git a/drivers/infiniband/hw/hns/hns_roce_db.c b/drivers/infiniband/hw/hns/hns_roce_db.c
index 987f2811d2c4..ebee2782a573 100644
--- a/drivers/infiniband/hw/hns/hns_roce_db.c
+++ b/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);