diff options
Diffstat (limited to '')
-rw-r--r-- | drivers/infiniband/hw/mlx4/doorbell.c | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/drivers/infiniband/hw/mlx4/doorbell.c b/drivers/infiniband/hw/mlx4/doorbell.c new file mode 100644 index 000000000..c51740986 --- /dev/null +++ b/drivers/infiniband/hw/mlx4/doorbell.c @@ -0,0 +1,96 @@ +/* + * Copyright (c) 2007 Cisco Systems, Inc. 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/slab.h> + +#include "mlx4_ib.h" + +struct mlx4_ib_user_db_page { + struct list_head list; + struct ib_umem *umem; + unsigned long user_virt; + int refcnt; +}; + +int mlx4_ib_db_map_user(struct mlx4_ib_ucontext *context, unsigned long virt, + struct mlx4_db *db) +{ + struct mlx4_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 (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, virt & PAGE_MASK, + PAGE_SIZE, 0, 0); + if (IS_ERR(page->umem)) { + err = PTR_ERR(page->umem); + kfree(page); + goto out; + } + + list_add(&page->list, &context->db_page_list); + +found: + db->dma = sg_dma_address(page->umem->sg_head.sgl) + (virt & ~PAGE_MASK); + db->u.user_page = page; + ++page->refcnt; + +out: + mutex_unlock(&context->db_page_mutex); + + return err; +} + +void mlx4_ib_db_unmap_user(struct mlx4_ib_ucontext *context, struct mlx4_db *db) +{ + mutex_lock(&context->db_page_mutex); + + if (!--db->u.user_page->refcnt) { + list_del(&db->u.user_page->list); + ib_umem_release(db->u.user_page->umem); + kfree(db->u.user_page); + } + + mutex_unlock(&context->db_page_mutex); +} |