RDMA/hns: Support rq record doorbell for the user space

This patch adds interfaces and definitions to support the rq record
doorbell for the user 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, 68 insertions, 0 deletions

diff --git a/drivers/infiniband/hw/hns/hns_roce_db.c b/drivers/infiniband/hw/hns/hns_roce_db.c
new file mode 100644
index 000000000000..987f2811d2c4
--- /dev/null
+++ b/drivers/infiniband/hw/hns/hns_roce_db.c
@@ -0,0 +1,68 @@
+/* SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) */
+/*
+ * Copyright (c) 2017 Hisilicon Limited.
+ * Copyright (c) 2007, 2008 Mellanox Technologies. All rights reserved.
+ */
+
+#include <linux/platform_device.h>
+#include <rdma/ib_umem.h>
+#include "hns_roce_device.h"
+
+int hns_roce_db_map_user(struct hns_roce_ucontext *context, unsigned long virt,
+			 struct hns_roce_db *db)
+{
+	struct hns_roce_user_db_page *page;
+	int ret = 0;
+
+	mutex_lock(&context->page_mutex);
+
+	list_for_each_entry(page, &context->page_list, list)
+		if (page->user_virt == (virt & PAGE_MASK))
+			goto found;
+
+	page = kmalloc(sizeof(*page), GFP_KERNEL);
+	if (!page) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	refcount_set(&page->refcount, 1);
+	page->user_virt = (virt & PAGE_MASK);
+	page->umem = ib_umem_get(&context->ibucontext, virt & PAGE_MASK,
+				 PAGE_SIZE, 0, 0);
+	if (IS_ERR(page->umem)) {
+		ret = PTR_ERR(page->umem);
+		kfree(page);
+		goto out;
+	}
+
+	list_add(&page->list, &context->page_list);
+
+found:
+	db->dma = sg_dma_address(page->umem->sg_head.sgl) +
+		  (virt & ~PAGE_MASK);
+	db->u.user_page = page;
+	refcount_inc(&page->refcount);
+
+out:
+	mutex_unlock(&context->page_mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL(hns_roce_db_map_user);
+
+void hns_roce_db_unmap_user(struct hns_roce_ucontext *context,
+			    struct hns_roce_db *db)
+{
+	mutex_lock(&context->page_mutex);
+
+	refcount_dec(&db->u.user_page->refcount);
+	if (refcount_dec_if_one(&db->u.user_page->refcount)) {
+		list_del(&db->u.user_page->list);
+		ib_umem_release(db->u.user_page->umem);
+		kfree(db->u.user_page);
+	}
+
+	mutex_unlock(&context->page_mutex);
+}
+EXPORT_SYMBOL(hns_roce_db_unmap_user);