xref: /openbmc/linux/include/rdma/ib_umem.h (revision 62eab49f)
1 /* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
2 /*
3  * Copyright (c) 2007 Cisco Systems.  All rights reserved.
4  * Copyright (c) 2020 Intel Corporation.  All rights reserved.
5  */
6 
7 #ifndef IB_UMEM_H
8 #define IB_UMEM_H
9 
10 #include <linux/list.h>
11 #include <linux/scatterlist.h>
12 #include <linux/workqueue.h>
13 #include <rdma/ib_verbs.h>
14 
15 struct ib_ucontext;
16 struct ib_umem_odp;
17 struct dma_buf_attach_ops;
18 
19 struct ib_umem {
20 	struct ib_device       *ibdev;
21 	struct mm_struct       *owning_mm;
22 	u64 iova;
23 	size_t			length;
24 	unsigned long		address;
25 	u32 writable : 1;
26 	u32 is_odp : 1;
27 	u32 is_dmabuf : 1;
28 	struct work_struct	work;
29 	struct sg_table sg_head;
30 	int             nmap;
31 	unsigned int    sg_nents;
32 };
33 
34 struct ib_umem_dmabuf {
35 	struct ib_umem umem;
36 	struct dma_buf_attachment *attach;
37 	struct sg_table *sgt;
38 	struct scatterlist *first_sg;
39 	struct scatterlist *last_sg;
40 	unsigned long first_sg_offset;
41 	unsigned long last_sg_trim;
42 	void *private;
43 };
44 
45 static inline struct ib_umem_dmabuf *to_ib_umem_dmabuf(struct ib_umem *umem)
46 {
47 	return container_of(umem, struct ib_umem_dmabuf, umem);
48 }
49 
50 /* Returns the offset of the umem start relative to the first page. */
51 static inline int ib_umem_offset(struct ib_umem *umem)
52 {
53 	return umem->address & ~PAGE_MASK;
54 }
55 
56 static inline unsigned long ib_umem_dma_offset(struct ib_umem *umem,
57 					       unsigned long pgsz)
58 {
59 	return (sg_dma_address(umem->sg_head.sgl) + ib_umem_offset(umem)) &
60 	       (pgsz - 1);
61 }
62 
63 static inline size_t ib_umem_num_dma_blocks(struct ib_umem *umem,
64 					    unsigned long pgsz)
65 {
66 	return (size_t)((ALIGN(umem->iova + umem->length, pgsz) -
67 			 ALIGN_DOWN(umem->iova, pgsz))) /
68 	       pgsz;
69 }
70 
71 static inline size_t ib_umem_num_pages(struct ib_umem *umem)
72 {
73 	return ib_umem_num_dma_blocks(umem, PAGE_SIZE);
74 }
75 
76 static inline void __rdma_umem_block_iter_start(struct ib_block_iter *biter,
77 						struct ib_umem *umem,
78 						unsigned long pgsz)
79 {
80 	__rdma_block_iter_start(biter, umem->sg_head.sgl, umem->nmap, pgsz);
81 }
82 
83 /**
84  * rdma_umem_for_each_dma_block - iterate over contiguous DMA blocks of the umem
85  * @umem: umem to iterate over
86  * @pgsz: Page size to split the list into
87  *
88  * pgsz must be <= PAGE_SIZE or computed by ib_umem_find_best_pgsz(). The
89  * returned DMA blocks will be aligned to pgsz and span the range:
90  * ALIGN_DOWN(umem->address, pgsz) to ALIGN(umem->address + umem->length, pgsz)
91  *
92  * Performs exactly ib_umem_num_dma_blocks() iterations.
93  */
94 #define rdma_umem_for_each_dma_block(umem, biter, pgsz)                        \
95 	for (__rdma_umem_block_iter_start(biter, umem, pgsz);                  \
96 	     __rdma_block_iter_next(biter);)
97 
98 #ifdef CONFIG_INFINIBAND_USER_MEM
99 
100 struct ib_umem *ib_umem_get(struct ib_device *device, unsigned long addr,
101 			    size_t size, int access);
102 void ib_umem_release(struct ib_umem *umem);
103 int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset,
104 		      size_t length);
105 unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem,
106 				     unsigned long pgsz_bitmap,
107 				     unsigned long virt);
108 
109 /**
110  * ib_umem_find_best_pgoff - Find best HW page size
111  *
112  * @umem: umem struct
113  * @pgsz_bitmap bitmap of HW supported page sizes
114  * @pgoff_bitmask: Mask of bits that can be represented with an offset
115  *
116  * This is very similar to ib_umem_find_best_pgsz() except instead of accepting
117  * an IOVA it accepts a bitmask specifying what address bits can be represented
118  * with a page offset.
119  *
120  * For instance if the HW has multiple page sizes, requires 64 byte alignemnt,
121  * and can support aligned offsets up to 4032 then pgoff_bitmask would be
122  * "111111000000".
123  *
124  * If the pgoff_bitmask requires either alignment in the low bit or an
125  * unavailable page size for the high bits, this function returns 0.
126  */
127 static inline unsigned long ib_umem_find_best_pgoff(struct ib_umem *umem,
128 						    unsigned long pgsz_bitmap,
129 						    u64 pgoff_bitmask)
130 {
131 	struct scatterlist *sg = umem->sg_head.sgl;
132 	dma_addr_t dma_addr;
133 
134 	dma_addr = sg_dma_address(sg) + (umem->address & ~PAGE_MASK);
135 	return ib_umem_find_best_pgsz(umem, pgsz_bitmap,
136 				      dma_addr & pgoff_bitmask);
137 }
138 
139 struct ib_umem_dmabuf *ib_umem_dmabuf_get(struct ib_device *device,
140 					  unsigned long offset, size_t size,
141 					  int fd, int access,
142 					  const struct dma_buf_attach_ops *ops);
143 int ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf *umem_dmabuf);
144 void ib_umem_dmabuf_unmap_pages(struct ib_umem_dmabuf *umem_dmabuf);
145 void ib_umem_dmabuf_release(struct ib_umem_dmabuf *umem_dmabuf);
146 
147 #else /* CONFIG_INFINIBAND_USER_MEM */
148 
149 #include <linux/err.h>
150 
151 static inline struct ib_umem *ib_umem_get(struct ib_device *device,
152 					  unsigned long addr, size_t size,
153 					  int access)
154 {
155 	return ERR_PTR(-EOPNOTSUPP);
156 }
157 static inline void ib_umem_release(struct ib_umem *umem) { }
158 static inline int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset,
159 		      		    size_t length) {
160 	return -EOPNOTSUPP;
161 }
162 static inline unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem,
163 						   unsigned long pgsz_bitmap,
164 						   unsigned long virt)
165 {
166 	return 0;
167 }
168 static inline unsigned long ib_umem_find_best_pgoff(struct ib_umem *umem,
169 						    unsigned long pgsz_bitmap,
170 						    u64 pgoff_bitmask)
171 {
172 	return 0;
173 }
174 static inline
175 struct ib_umem_dmabuf *ib_umem_dmabuf_get(struct ib_device *device,
176 					  unsigned long offset,
177 					  size_t size, int fd,
178 					  int access,
179 					  struct dma_buf_attach_ops *ops)
180 {
181 	return ERR_PTR(-EOPNOTSUPP);
182 }
183 static inline int ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf *umem_dmabuf)
184 {
185 	return -EOPNOTSUPP;
186 }
187 static inline void ib_umem_dmabuf_unmap_pages(struct ib_umem_dmabuf *umem_dmabuf) { }
188 static inline void ib_umem_dmabuf_release(struct ib_umem_dmabuf *umem_dmabuf) { }
189 
190 #endif /* CONFIG_INFINIBAND_USER_MEM */
191 #endif /* IB_UMEM_H */
192