xref: /openbmc/linux/include/rdma/ib_umem.h (revision a71597b4)
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 sg_append_table sgt_append;
29 };
30 
31 struct ib_umem_dmabuf {
32 	struct ib_umem umem;
33 	struct dma_buf_attachment *attach;
34 	struct sg_table *sgt;
35 	struct scatterlist *first_sg;
36 	struct scatterlist *last_sg;
37 	unsigned long first_sg_offset;
38 	unsigned long last_sg_trim;
39 	void *private;
40 	u8 pinned : 1;
41 };
42 
43 static inline struct ib_umem_dmabuf *to_ib_umem_dmabuf(struct ib_umem *umem)
44 {
45 	return container_of(umem, struct ib_umem_dmabuf, umem);
46 }
47 
48 /* Returns the offset of the umem start relative to the first page. */
49 static inline int ib_umem_offset(struct ib_umem *umem)
50 {
51 	return umem->address & ~PAGE_MASK;
52 }
53 
54 static inline unsigned long ib_umem_dma_offset(struct ib_umem *umem,
55 					       unsigned long pgsz)
56 {
57 	return (sg_dma_address(umem->sgt_append.sgt.sgl) + ib_umem_offset(umem)) &
58 	       (pgsz - 1);
59 }
60 
61 static inline size_t ib_umem_num_dma_blocks(struct ib_umem *umem,
62 					    unsigned long pgsz)
63 {
64 	return (size_t)((ALIGN(umem->iova + umem->length, pgsz) -
65 			 ALIGN_DOWN(umem->iova, pgsz))) /
66 	       pgsz;
67 }
68 
69 static inline size_t ib_umem_num_pages(struct ib_umem *umem)
70 {
71 	return ib_umem_num_dma_blocks(umem, PAGE_SIZE);
72 }
73 
74 static inline void __rdma_umem_block_iter_start(struct ib_block_iter *biter,
75 						struct ib_umem *umem,
76 						unsigned long pgsz)
77 {
78 	__rdma_block_iter_start(biter, umem->sgt_append.sgt.sgl,
79 				umem->sgt_append.sgt.nents, pgsz);
80 	biter->__sg_advance = ib_umem_offset(umem) & ~(pgsz - 1);
81 	biter->__sg_numblocks = ib_umem_num_dma_blocks(umem, pgsz);
82 }
83 
84 static inline bool __rdma_umem_block_iter_next(struct ib_block_iter *biter)
85 {
86 	return __rdma_block_iter_next(biter) && biter->__sg_numblocks--;
87 }
88 
89 /**
90  * rdma_umem_for_each_dma_block - iterate over contiguous DMA blocks of the umem
91  * @umem: umem to iterate over
92  * @pgsz: Page size to split the list into
93  *
94  * pgsz must be <= PAGE_SIZE or computed by ib_umem_find_best_pgsz(). The
95  * returned DMA blocks will be aligned to pgsz and span the range:
96  * ALIGN_DOWN(umem->address, pgsz) to ALIGN(umem->address + umem->length, pgsz)
97  *
98  * Performs exactly ib_umem_num_dma_blocks() iterations.
99  */
100 #define rdma_umem_for_each_dma_block(umem, biter, pgsz)                        \
101 	for (__rdma_umem_block_iter_start(biter, umem, pgsz);                  \
102 	     __rdma_umem_block_iter_next(biter);)
103 
104 #ifdef CONFIG_INFINIBAND_USER_MEM
105 
106 struct ib_umem *ib_umem_get(struct ib_device *device, unsigned long addr,
107 			    size_t size, int access);
108 void ib_umem_release(struct ib_umem *umem);
109 int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset,
110 		      size_t length);
111 unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem,
112 				     unsigned long pgsz_bitmap,
113 				     unsigned long virt);
114 
115 /**
116  * ib_umem_find_best_pgoff - Find best HW page size
117  *
118  * @umem: umem struct
119  * @pgsz_bitmap bitmap of HW supported page sizes
120  * @pgoff_bitmask: Mask of bits that can be represented with an offset
121  *
122  * This is very similar to ib_umem_find_best_pgsz() except instead of accepting
123  * an IOVA it accepts a bitmask specifying what address bits can be represented
124  * with a page offset.
125  *
126  * For instance if the HW has multiple page sizes, requires 64 byte alignemnt,
127  * and can support aligned offsets up to 4032 then pgoff_bitmask would be
128  * "111111000000".
129  *
130  * If the pgoff_bitmask requires either alignment in the low bit or an
131  * unavailable page size for the high bits, this function returns 0.
132  */
133 static inline unsigned long ib_umem_find_best_pgoff(struct ib_umem *umem,
134 						    unsigned long pgsz_bitmap,
135 						    u64 pgoff_bitmask)
136 {
137 	struct scatterlist *sg = umem->sgt_append.sgt.sgl;
138 	dma_addr_t dma_addr;
139 
140 	dma_addr = sg_dma_address(sg) + (umem->address & ~PAGE_MASK);
141 	return ib_umem_find_best_pgsz(umem, pgsz_bitmap,
142 				      dma_addr & pgoff_bitmask);
143 }
144 
145 struct ib_umem_dmabuf *ib_umem_dmabuf_get(struct ib_device *device,
146 					  unsigned long offset, size_t size,
147 					  int fd, int access,
148 					  const struct dma_buf_attach_ops *ops);
149 struct ib_umem_dmabuf *ib_umem_dmabuf_get_pinned(struct ib_device *device,
150 						 unsigned long offset,
151 						 size_t size, int fd,
152 						 int access);
153 int ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf *umem_dmabuf);
154 void ib_umem_dmabuf_unmap_pages(struct ib_umem_dmabuf *umem_dmabuf);
155 void ib_umem_dmabuf_release(struct ib_umem_dmabuf *umem_dmabuf);
156 
157 #else /* CONFIG_INFINIBAND_USER_MEM */
158 
159 #include <linux/err.h>
160 
161 static inline struct ib_umem *ib_umem_get(struct ib_device *device,
162 					  unsigned long addr, size_t size,
163 					  int access)
164 {
165 	return ERR_PTR(-EOPNOTSUPP);
166 }
167 static inline void ib_umem_release(struct ib_umem *umem) { }
168 static inline int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset,
169 		      		    size_t length) {
170 	return -EOPNOTSUPP;
171 }
172 static inline unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem,
173 						   unsigned long pgsz_bitmap,
174 						   unsigned long virt)
175 {
176 	return 0;
177 }
178 static inline unsigned long ib_umem_find_best_pgoff(struct ib_umem *umem,
179 						    unsigned long pgsz_bitmap,
180 						    u64 pgoff_bitmask)
181 {
182 	return 0;
183 }
184 static inline
185 struct ib_umem_dmabuf *ib_umem_dmabuf_get(struct ib_device *device,
186 					  unsigned long offset,
187 					  size_t size, int fd,
188 					  int access,
189 					  struct dma_buf_attach_ops *ops)
190 {
191 	return ERR_PTR(-EOPNOTSUPP);
192 }
193 static inline struct ib_umem_dmabuf *
194 ib_umem_dmabuf_get_pinned(struct ib_device *device, unsigned long offset,
195 			  size_t size, int fd, int access)
196 {
197 	return ERR_PTR(-EOPNOTSUPP);
198 }
199 static inline int ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf *umem_dmabuf)
200 {
201 	return -EOPNOTSUPP;
202 }
203 static inline void ib_umem_dmabuf_unmap_pages(struct ib_umem_dmabuf *umem_dmabuf) { }
204 static inline void ib_umem_dmabuf_release(struct ib_umem_dmabuf *umem_dmabuf) { }
205 
206 #endif /* CONFIG_INFINIBAND_USER_MEM */
207 #endif /* IB_UMEM_H */
208