xref: /openbmc/linux/drivers/infiniband/hw/mlx5/mem.c (revision 206204a1)
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 
59 	addr = addr >> PAGE_SHIFT;
60 	tmp = (unsigned long)addr;
61 	m = find_first_bit(&tmp, sizeof(tmp));
62 	skip = 1 << m;
63 	mask = skip - 1;
64 	i = 0;
65 	for_each_sg(umem->sg_head.sgl, sg, umem->nmap, entry) {
66 		len = sg_dma_len(sg) >> PAGE_SHIFT;
67 		pfn = sg_dma_address(sg) >> PAGE_SHIFT;
68 		for (k = 0; k < len; k++) {
69 			if (!(i & mask)) {
70 				tmp = (unsigned long)pfn;
71 				m = min(m, find_first_bit(&tmp, sizeof(tmp)));
72 				skip = 1 << m;
73 				mask = skip - 1;
74 				base = pfn;
75 				p = 0;
76 			} else {
77 				if (base + p != pfn) {
78 					tmp = (unsigned long)p;
79 					m = find_first_bit(&tmp, sizeof(tmp));
80 					skip = 1 << m;
81 					mask = skip - 1;
82 					base = pfn;
83 					p = 0;
84 				}
85 			}
86 			p++;
87 			i++;
88 		}
89 	}
90 
91 	if (i) {
92 		m = min_t(unsigned long, ilog2(roundup_pow_of_two(i)), m);
93 
94 		if (order)
95 			*order = ilog2(roundup_pow_of_two(i) >> m);
96 
97 		*ncont = DIV_ROUND_UP(i, (1 << m));
98 	} else {
99 		m  = 0;
100 
101 		if (order)
102 			*order = 0;
103 
104 		*ncont = 0;
105 	}
106 	*shift = PAGE_SHIFT + m;
107 	*count = i;
108 }
109 
110 void mlx5_ib_populate_pas(struct mlx5_ib_dev *dev, struct ib_umem *umem,
111 			  int page_shift, __be64 *pas, int umr)
112 {
113 	int shift = page_shift - PAGE_SHIFT;
114 	int mask = (1 << shift) - 1;
115 	int i, k;
116 	u64 cur = 0;
117 	u64 base;
118 	int len;
119 	struct scatterlist *sg;
120 	int entry;
121 
122 	i = 0;
123 	for_each_sg(umem->sg_head.sgl, sg, umem->nmap, entry) {
124 		len = sg_dma_len(sg) >> PAGE_SHIFT;
125 		base = sg_dma_address(sg);
126 		for (k = 0; k < len; k++) {
127 			if (!(i & mask)) {
128 				cur = base + (k << PAGE_SHIFT);
129 				if (umr)
130 					cur |= 3;
131 
132 				pas[i >> shift] = cpu_to_be64(cur);
133 				mlx5_ib_dbg(dev, "pas[%d] 0x%llx\n",
134 					    i >> shift, be64_to_cpu(pas[i >> shift]));
135 			}  else
136 				mlx5_ib_dbg(dev, "=====> 0x%llx\n",
137 					    base + (k << PAGE_SHIFT));
138 			i++;
139 		}
140 	}
141 }
142 
143 int mlx5_ib_get_buf_offset(u64 addr, int page_shift, u32 *offset)
144 {
145 	u64 page_size;
146 	u64 page_mask;
147 	u64 off_size;
148 	u64 off_mask;
149 	u64 buf_off;
150 
151 	page_size = 1 << page_shift;
152 	page_mask = page_size - 1;
153 	buf_off = addr & page_mask;
154 	off_size = page_size >> 6;
155 	off_mask = off_size - 1;
156 
157 	if (buf_off & off_mask)
158 		return -EINVAL;
159 
160 	*offset = buf_off >> ilog2(off_size);
161 	return 0;
162 }
163