106 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			106 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
 | |
|  * 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);
 | |
| }
 |