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-rw-r--r--drivers/infiniband/hw/mlx5/doorbell.c105
1 files changed, 105 insertions, 0 deletions
diff --git a/drivers/infiniband/hw/mlx5/doorbell.c b/drivers/infiniband/hw/mlx5/doorbell.c
new file mode 100644
index 000000000..e32111117
--- /dev/null
+++ b/drivers/infiniband/hw/mlx5/doorbell.c
@@ -0,0 +1,105 @@
+/*
+ * Copyright (c) 2013-2015, Mellanox Technologies. All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses. You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above
+ * copyright notice, this list of conditions and the following
+ * disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following
+ * disclaimer in the documentation and/or other materials
+ * provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <linux/kref.h>
+#include <linux/slab.h>
+#include <linux/sched/mm.h>
+#include <rdma/ib_umem.h>
+
+#include "mlx5_ib.h"
+
+struct mlx5_ib_user_db_page {
+ struct list_head list;
+ struct ib_umem *umem;
+ unsigned long user_virt;
+ int refcnt;
+ struct mm_struct *mm;
+};
+
+int mlx5_ib_db_map_user(struct mlx5_ib_ucontext *context, unsigned long virt,
+ struct mlx5_db *db)
+{
+ struct mlx5_ib_user_db_page *page;
+ int err = 0;
+
+ mutex_lock(&context->db_page_mutex);
+
+ list_for_each_entry(page, &context->db_page_list, list)
+ if ((current->mm == page->mm) &&
+ (page->user_virt == (virt & PAGE_MASK)))
+ goto found;
+
+ page = kmalloc(sizeof(*page), GFP_KERNEL);
+ if (!page) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ page->user_virt = (virt & PAGE_MASK);
+ page->refcnt = 0;
+ page->umem = ib_umem_get(context->ibucontext.device, virt & PAGE_MASK,
+ PAGE_SIZE, 0);
+ if (IS_ERR(page->umem)) {
+ err = PTR_ERR(page->umem);
+ kfree(page);
+ goto out;
+ }
+ mmgrab(current->mm);
+ page->mm = current->mm;
+
+ list_add(&page->list, &context->db_page_list);
+
+found:
+ db->dma = sg_dma_address(page->umem->sgt_append.sgt.sgl) +
+ (virt & ~PAGE_MASK);
+ db->u.user_page = page;
+ ++page->refcnt;
+
+out:
+ mutex_unlock(&context->db_page_mutex);
+
+ return err;
+}
+
+void mlx5_ib_db_unmap_user(struct mlx5_ib_ucontext *context, struct mlx5_db *db)
+{
+ mutex_lock(&context->db_page_mutex);
+
+ if (!--db->u.user_page->refcnt) {
+ list_del(&db->u.user_page->list);
+ mmdrop(db->u.user_page->mm);
+ ib_umem_release(db->u.user_page->umem);
+ kfree(db->u.user_page);
+ }
+
+ mutex_unlock(&context->db_page_mutex);
+}