xref: /openbmc/linux/drivers/infiniband/hw/mlx5/mem.c (revision 6279eb3d)
1 /*
2  * Copyright (c) 2013-2015, Mellanox Technologies. 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 <rdma/ib_umem_odp.h>
36 #include "mlx5_ib.h"
37 
38 /* @umem: umem object to scan
39  * @addr: ib virtual address requested by the user
40  * @max_page_shift: high limit for page_shift - 0 means no limit
41  * @count: number of PAGE_SIZE pages covered by umem
42  * @shift: page shift for the compound pages found in the region
43  * @ncont: number of compund pages
44  * @order: log2 of the number of compound pages
45  */
46 void mlx5_ib_cont_pages(struct ib_umem *umem, u64 addr,
47 			unsigned long max_page_shift,
48 			int *count, int *shift,
49 			int *ncont, int *order)
50 {
51 	unsigned long tmp;
52 	unsigned long m;
53 	u64 base = ~0, p = 0;
54 	u64 len, pfn;
55 	int i = 0;
56 	struct scatterlist *sg;
57 	int entry;
58 
59 	addr = addr >> PAGE_SHIFT;
60 	tmp = (unsigned long)addr;
61 	m = find_first_bit(&tmp, BITS_PER_LONG);
62 	if (max_page_shift)
63 		m = min_t(unsigned long, max_page_shift - PAGE_SHIFT, m);
64 
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 		if (base + p != pfn) {
69 			/* If either the offset or the new
70 			 * base are unaligned update m
71 			 */
72 			tmp = (unsigned long)(pfn | p);
73 			if (!IS_ALIGNED(tmp, 1 << m))
74 				m = find_first_bit(&tmp, BITS_PER_LONG);
75 
76 			base = pfn;
77 			p = 0;
78 		}
79 
80 		p += len;
81 		i += len;
82 	}
83 
84 	if (i) {
85 		m = min_t(unsigned long, ilog2(roundup_pow_of_two(i)), m);
86 
87 		if (order)
88 			*order = ilog2(roundup_pow_of_two(i) >> m);
89 
90 		*ncont = DIV_ROUND_UP(i, (1 << m));
91 	} else {
92 		m  = 0;
93 
94 		if (order)
95 			*order = 0;
96 
97 		*ncont = 0;
98 	}
99 	*shift = PAGE_SHIFT + m;
100 	*count = i;
101 }
102 
103 static u64 umem_dma_to_mtt(dma_addr_t umem_dma)
104 {
105 	u64 mtt_entry = umem_dma & ODP_DMA_ADDR_MASK;
106 
107 	if (umem_dma & ODP_READ_ALLOWED_BIT)
108 		mtt_entry |= MLX5_IB_MTT_READ;
109 	if (umem_dma & ODP_WRITE_ALLOWED_BIT)
110 		mtt_entry |= MLX5_IB_MTT_WRITE;
111 
112 	return mtt_entry;
113 }
114 
115 /*
116  * Populate the given array with bus addresses from the umem.
117  *
118  * dev - mlx5_ib device
119  * umem - umem to use to fill the pages
120  * page_shift - determines the page size used in the resulting array
121  * offset - offset into the umem to start from,
122  *          only implemented for ODP umems
123  * num_pages - total number of pages to fill
124  * pas - bus addresses array to fill
125  * access_flags - access flags to set on all present pages.
126 		  use enum mlx5_ib_mtt_access_flags for this.
127  */
128 void __mlx5_ib_populate_pas(struct mlx5_ib_dev *dev, struct ib_umem *umem,
129 			    int page_shift, size_t offset, size_t num_pages,
130 			    __be64 *pas, int access_flags)
131 {
132 	int shift = page_shift - PAGE_SHIFT;
133 	int mask = (1 << shift) - 1;
134 	int i, k, idx;
135 	u64 cur = 0;
136 	u64 base;
137 	int len;
138 	struct scatterlist *sg;
139 	int entry;
140 
141 	if (umem->is_odp) {
142 		WARN_ON(shift != 0);
143 		WARN_ON(access_flags != (MLX5_IB_MTT_READ | MLX5_IB_MTT_WRITE));
144 
145 		for (i = 0; i < num_pages; ++i) {
146 			dma_addr_t pa =
147 				to_ib_umem_odp(umem)->dma_list[offset + i];
148 
149 			pas[i] = cpu_to_be64(umem_dma_to_mtt(pa));
150 		}
151 		return;
152 	}
153 
154 	i = 0;
155 	for_each_sg(umem->sg_head.sgl, sg, umem->nmap, entry) {
156 		len = sg_dma_len(sg) >> PAGE_SHIFT;
157 		base = sg_dma_address(sg);
158 
159 		/* Skip elements below offset */
160 		if (i + len < offset << shift) {
161 			i += len;
162 			continue;
163 		}
164 
165 		/* Skip pages below offset */
166 		if (i < offset << shift) {
167 			k = (offset << shift) - i;
168 			i = offset << shift;
169 		} else {
170 			k = 0;
171 		}
172 
173 		for (; k < len; k++) {
174 			if (!(i & mask)) {
175 				cur = base + (k << PAGE_SHIFT);
176 				cur |= access_flags;
177 				idx = (i >> shift) - offset;
178 
179 				pas[idx] = cpu_to_be64(cur);
180 				mlx5_ib_dbg(dev, "pas[%d] 0x%llx\n",
181 					    i >> shift, be64_to_cpu(pas[idx]));
182 			}
183 			i++;
184 
185 			/* Stop after num_pages reached */
186 			if (i >> shift >= offset + num_pages)
187 				return;
188 		}
189 	}
190 }
191 
192 void mlx5_ib_populate_pas(struct mlx5_ib_dev *dev, struct ib_umem *umem,
193 			  int page_shift, __be64 *pas, int access_flags)
194 {
195 	return __mlx5_ib_populate_pas(dev, umem, page_shift, 0,
196 				      ib_umem_num_pages(umem), pas,
197 				      access_flags);
198 }
199 int mlx5_ib_get_buf_offset(u64 addr, int page_shift, u32 *offset)
200 {
201 	u64 page_size;
202 	u64 page_mask;
203 	u64 off_size;
204 	u64 off_mask;
205 	u64 buf_off;
206 
207 	page_size = (u64)1 << page_shift;
208 	page_mask = page_size - 1;
209 	buf_off = addr & page_mask;
210 	off_size = page_size >> 6;
211 	off_mask = off_size - 1;
212 
213 	if (buf_off & off_mask)
214 		return -EINVAL;
215 
216 	*offset = buf_off >> ilog2(off_size);
217 	return 0;
218 }
219