xref: /openbmc/linux/include/rdma/ib_umem.h (revision 835fd614)
1 /* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
2 /*
3  * Copyright (c) 2007 Cisco Systems.  All rights reserved.
4  */
5 
6 #ifndef IB_UMEM_H
7 #define IB_UMEM_H
8 
9 #include <linux/list.h>
10 #include <linux/scatterlist.h>
11 #include <linux/workqueue.h>
12 #include <rdma/ib_verbs.h>
13 
14 struct ib_ucontext;
15 struct ib_umem_odp;
16 
17 struct ib_umem {
18 	struct ib_device       *ibdev;
19 	struct mm_struct       *owning_mm;
20 	u64 iova;
21 	size_t			length;
22 	unsigned long		address;
23 	u32 writable : 1;
24 	u32 is_odp : 1;
25 	struct work_struct	work;
26 	struct sg_table sg_head;
27 	int             nmap;
28 	unsigned int    sg_nents;
29 };
30 
31 /* Returns the offset of the umem start relative to the first page. */
32 static inline int ib_umem_offset(struct ib_umem *umem)
33 {
34 	return umem->address & ~PAGE_MASK;
35 }
36 
37 static inline size_t ib_umem_num_dma_blocks(struct ib_umem *umem,
38 					    unsigned long pgsz)
39 {
40 	return (size_t)((ALIGN(umem->iova + umem->length, pgsz) -
41 			 ALIGN_DOWN(umem->iova, pgsz))) /
42 	       pgsz;
43 }
44 
45 static inline size_t ib_umem_num_pages(struct ib_umem *umem)
46 {
47 	return ib_umem_num_dma_blocks(umem, PAGE_SIZE);
48 }
49 
50 static inline void __rdma_umem_block_iter_start(struct ib_block_iter *biter,
51 						struct ib_umem *umem,
52 						unsigned long pgsz)
53 {
54 	__rdma_block_iter_start(biter, umem->sg_head.sgl, umem->nmap, pgsz);
55 }
56 
57 /**
58  * rdma_umem_for_each_dma_block - iterate over contiguous DMA blocks of the umem
59  * @umem: umem to iterate over
60  * @pgsz: Page size to split the list into
61  *
62  * pgsz must be <= PAGE_SIZE or computed by ib_umem_find_best_pgsz(). The
63  * returned DMA blocks will be aligned to pgsz and span the range:
64  * ALIGN_DOWN(umem->address, pgsz) to ALIGN(umem->address + umem->length, pgsz)
65  *
66  * Performs exactly ib_umem_num_dma_blocks() iterations.
67  */
68 #define rdma_umem_for_each_dma_block(umem, biter, pgsz)                        \
69 	for (__rdma_umem_block_iter_start(biter, umem, pgsz);                  \
70 	     __rdma_block_iter_next(biter);)
71 
72 #ifdef CONFIG_INFINIBAND_USER_MEM
73 
74 struct ib_umem *ib_umem_get(struct ib_device *device, unsigned long addr,
75 			    size_t size, int access);
76 void ib_umem_release(struct ib_umem *umem);
77 int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset,
78 		      size_t length);
79 unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem,
80 				     unsigned long pgsz_bitmap,
81 				     unsigned long virt);
82 
83 #else /* CONFIG_INFINIBAND_USER_MEM */
84 
85 #include <linux/err.h>
86 
87 static inline struct ib_umem *ib_umem_get(struct ib_device *device,
88 					  unsigned long addr, size_t size,
89 					  int access)
90 {
91 	return ERR_PTR(-EINVAL);
92 }
93 static inline void ib_umem_release(struct ib_umem *umem) { }
94 static inline int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset,
95 		      		    size_t length) {
96 	return -EINVAL;
97 }
98 static inline unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem,
99 						   unsigned long pgsz_bitmap,
100 						   unsigned long virt)
101 {
102 	return 0;
103 }
104 
105 #endif /* CONFIG_INFINIBAND_USER_MEM */
106 
107 #endif /* IB_UMEM_H */
108