xref: /linux/include/rdma/ib_umem.h (revision 74ce1896c6c65b2f8cccbf59162d542988835835)
1 /*
2  * Copyright (c) 2007 Cisco Systems.  All rights reserved.
3  *
4  * This software is available to you under a choice of one of two
5  * licenses.  You may choose to be licensed under the terms of the GNU
6  * General Public License (GPL) Version 2, available from the file
7  * COPYING in the main directory of this source tree, or the
8  * OpenIB.org BSD license below:
9  *
10  *     Redistribution and use in source and binary forms, with or
11  *     without modification, are permitted provided that the following
12  *     conditions are met:
13  *
14  *      - Redistributions of source code must retain the above
15  *        copyright notice, this list of conditions and the following
16  *        disclaimer.
17  *
18  *      - Redistributions in binary form must reproduce the above
19  *        copyright notice, this list of conditions and the following
20  *        disclaimer in the documentation and/or other materials
21  *        provided with the distribution.
22  *
23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30  * SOFTWARE.
31  */
32 
33 #ifndef IB_UMEM_H
34 #define IB_UMEM_H
35 
36 #include <linux/list.h>
37 #include <linux/scatterlist.h>
38 #include <linux/workqueue.h>
39 
40 struct ib_ucontext;
41 struct ib_umem_odp;
42 
43 struct ib_umem {
44 	struct ib_ucontext     *context;
45 	size_t			length;
46 	unsigned long		address;
47 	int			page_shift;
48 	int                     writable;
49 	int                     hugetlb;
50 	struct work_struct	work;
51 	struct pid             *pid;
52 	struct mm_struct       *mm;
53 	unsigned long		diff;
54 	struct ib_umem_odp     *odp_data;
55 	struct sg_table sg_head;
56 	int             nmap;
57 	int             npages;
58 };
59 
60 /* Returns the offset of the umem start relative to the first page. */
61 static inline int ib_umem_offset(struct ib_umem *umem)
62 {
63 	return umem->address & (BIT(umem->page_shift) - 1);
64 }
65 
66 /* Returns the first page of an ODP umem. */
67 static inline unsigned long ib_umem_start(struct ib_umem *umem)
68 {
69 	return umem->address - ib_umem_offset(umem);
70 }
71 
72 /* Returns the address of the page after the last one of an ODP umem. */
73 static inline unsigned long ib_umem_end(struct ib_umem *umem)
74 {
75 	return ALIGN(umem->address + umem->length, BIT(umem->page_shift));
76 }
77 
78 static inline size_t ib_umem_num_pages(struct ib_umem *umem)
79 {
80 	return (ib_umem_end(umem) - ib_umem_start(umem)) >> umem->page_shift;
81 }
82 
83 #ifdef CONFIG_INFINIBAND_USER_MEM
84 
85 struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
86 			    size_t size, int access, int dmasync);
87 void ib_umem_release(struct ib_umem *umem);
88 int ib_umem_page_count(struct ib_umem *umem);
89 int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset,
90 		      size_t length);
91 
92 #else /* CONFIG_INFINIBAND_USER_MEM */
93 
94 #include <linux/err.h>
95 
96 static inline struct ib_umem *ib_umem_get(struct ib_ucontext *context,
97 					  unsigned long addr, size_t size,
98 					  int access, int dmasync) {
99 	return ERR_PTR(-EINVAL);
100 }
101 static inline void ib_umem_release(struct ib_umem *umem) { }
102 static inline int ib_umem_page_count(struct ib_umem *umem) { return 0; }
103 static inline int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset,
104 		      		    size_t length) {
105 	return -EINVAL;
106 }
107 #endif /* CONFIG_INFINIBAND_USER_MEM */
108 
109 #endif /* IB_UMEM_H */
110