xref: /openbmc/linux/drivers/infiniband/hw/mlx5/mem.c (revision 3c6a73cc)
1 /*
2  * Copyright (c) 2013, Mellanox Technologies inc.  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 #include <linux/module.h>
34 #include <rdma/ib_umem.h>
35 #include "mlx5_ib.h"
36 
37 /* @umem: umem object to scan
38  * @addr: ib virtual address requested by the user
39  * @count: number of PAGE_SIZE pages covered by umem
40  * @shift: page shift for the compound pages found in the region
41  * @ncont: number of compund pages
42  * @order: log2 of the number of compound pages
43  */
44 void mlx5_ib_cont_pages(struct ib_umem *umem, u64 addr, int *count, int *shift,
45 			int *ncont, int *order)
46 {
47 	unsigned long tmp;
48 	unsigned long m;
49 	int i, k;
50 	u64 base = 0;
51 	int p = 0;
52 	int skip;
53 	int mask;
54 	u64 len;
55 	u64 pfn;
56 	struct scatterlist *sg;
57 	int entry;
58 	unsigned long page_shift = ilog2(umem->page_size);
59 
60 	addr = addr >> page_shift;
61 	tmp = (unsigned long)addr;
62 	m = find_first_bit(&tmp, sizeof(tmp));
63 	skip = 1 << m;
64 	mask = skip - 1;
65 	i = 0;
66 	for_each_sg(umem->sg_head.sgl, sg, umem->nmap, entry) {
67 		len = sg_dma_len(sg) >> page_shift;
68 		pfn = sg_dma_address(sg) >> page_shift;
69 		for (k = 0; k < len; k++) {
70 			if (!(i & mask)) {
71 				tmp = (unsigned long)pfn;
72 				m = min(m, find_first_bit(&tmp, sizeof(tmp)));
73 				skip = 1 << m;
74 				mask = skip - 1;
75 				base = pfn;
76 				p = 0;
77 			} else {
78 				if (base + p != pfn) {
79 					tmp = (unsigned long)p;
80 					m = find_first_bit(&tmp, sizeof(tmp));
81 					skip = 1 << m;
82 					mask = skip - 1;
83 					base = pfn;
84 					p = 0;
85 				}
86 			}
87 			p++;
88 			i++;
89 		}
90 	}
91 
92 	if (i) {
93 		m = min_t(unsigned long, ilog2(roundup_pow_of_two(i)), m);
94 
95 		if (order)
96 			*order = ilog2(roundup_pow_of_two(i) >> m);
97 
98 		*ncont = DIV_ROUND_UP(i, (1 << m));
99 	} else {
100 		m  = 0;
101 
102 		if (order)
103 			*order = 0;
104 
105 		*ncont = 0;
106 	}
107 	*shift = page_shift + m;
108 	*count = i;
109 }
110 
111 void mlx5_ib_populate_pas(struct mlx5_ib_dev *dev, struct ib_umem *umem,
112 			  int page_shift, __be64 *pas, int umr)
113 {
114 	unsigned long umem_page_shift = ilog2(umem->page_size);
115 	int shift = page_shift - umem_page_shift;
116 	int mask = (1 << shift) - 1;
117 	int i, k;
118 	u64 cur = 0;
119 	u64 base;
120 	int len;
121 	struct scatterlist *sg;
122 	int entry;
123 
124 	i = 0;
125 	for_each_sg(umem->sg_head.sgl, sg, umem->nmap, entry) {
126 		len = sg_dma_len(sg) >> umem_page_shift;
127 		base = sg_dma_address(sg);
128 		for (k = 0; k < len; k++) {
129 			if (!(i & mask)) {
130 				cur = base + (k << umem_page_shift);
131 				if (umr)
132 					cur |= 3;
133 
134 				pas[i >> shift] = cpu_to_be64(cur);
135 				mlx5_ib_dbg(dev, "pas[%d] 0x%llx\n",
136 					    i >> shift, be64_to_cpu(pas[i >> shift]));
137 			}  else
138 				mlx5_ib_dbg(dev, "=====> 0x%llx\n",
139 					    base + (k << umem_page_shift));
140 			i++;
141 		}
142 	}
143 }
144 
145 int mlx5_ib_get_buf_offset(u64 addr, int page_shift, u32 *offset)
146 {
147 	u64 page_size;
148 	u64 page_mask;
149 	u64 off_size;
150 	u64 off_mask;
151 	u64 buf_off;
152 
153 	page_size = (u64)1 << page_shift;
154 	page_mask = page_size - 1;
155 	buf_off = addr & page_mask;
156 	off_size = page_size >> 6;
157 	off_mask = off_size - 1;
158 
159 	if (buf_off & off_mask)
160 		return -EINVAL;
161 
162 	*offset = buf_off >> ilog2(off_size);
163 	return 0;
164 }
165