xref: /openbmc/linux/drivers/infiniband/hw/mlx5/mem.c (revision b830f94f)
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 	if (umem->is_odp) {
60 		unsigned int page_shift = to_ib_umem_odp(umem)->page_shift;
61 
62 		*ncont = ib_umem_page_count(umem);
63 		*count = *ncont << (page_shift - PAGE_SHIFT);
64 		*shift = page_shift;
65 		if (order)
66 			*order = ilog2(roundup_pow_of_two(*ncont));
67 
68 		return;
69 	}
70 
71 	addr = addr >> PAGE_SHIFT;
72 	tmp = (unsigned long)addr;
73 	m = find_first_bit(&tmp, BITS_PER_LONG);
74 	if (max_page_shift)
75 		m = min_t(unsigned long, max_page_shift - PAGE_SHIFT, m);
76 
77 	for_each_sg(umem->sg_head.sgl, sg, umem->nmap, entry) {
78 		len = sg_dma_len(sg) >> PAGE_SHIFT;
79 		pfn = sg_dma_address(sg) >> PAGE_SHIFT;
80 		if (base + p != pfn) {
81 			/* If either the offset or the new
82 			 * base are unaligned update m
83 			 */
84 			tmp = (unsigned long)(pfn | p);
85 			if (!IS_ALIGNED(tmp, 1 << m))
86 				m = find_first_bit(&tmp, BITS_PER_LONG);
87 
88 			base = pfn;
89 			p = 0;
90 		}
91 
92 		p += len;
93 		i += len;
94 	}
95 
96 	if (i) {
97 		m = min_t(unsigned long, ilog2(roundup_pow_of_two(i)), m);
98 
99 		if (order)
100 			*order = ilog2(roundup_pow_of_two(i) >> m);
101 
102 		*ncont = DIV_ROUND_UP(i, (1 << m));
103 	} else {
104 		m  = 0;
105 
106 		if (order)
107 			*order = 0;
108 
109 		*ncont = 0;
110 	}
111 	*shift = PAGE_SHIFT + m;
112 	*count = i;
113 }
114 
115 static u64 umem_dma_to_mtt(dma_addr_t umem_dma)
116 {
117 	u64 mtt_entry = umem_dma & ODP_DMA_ADDR_MASK;
118 
119 	if (umem_dma & ODP_READ_ALLOWED_BIT)
120 		mtt_entry |= MLX5_IB_MTT_READ;
121 	if (umem_dma & ODP_WRITE_ALLOWED_BIT)
122 		mtt_entry |= MLX5_IB_MTT_WRITE;
123 
124 	return mtt_entry;
125 }
126 
127 /*
128  * Populate the given array with bus addresses from the umem.
129  *
130  * dev - mlx5_ib device
131  * umem - umem to use to fill the pages
132  * page_shift - determines the page size used in the resulting array
133  * offset - offset into the umem to start from,
134  *          only implemented for ODP umems
135  * num_pages - total number of pages to fill
136  * pas - bus addresses array to fill
137  * access_flags - access flags to set on all present pages.
138 		  use enum mlx5_ib_mtt_access_flags for this.
139  */
140 void __mlx5_ib_populate_pas(struct mlx5_ib_dev *dev, struct ib_umem *umem,
141 			    int page_shift, size_t offset, size_t num_pages,
142 			    __be64 *pas, int access_flags)
143 {
144 	int shift = page_shift - PAGE_SHIFT;
145 	int mask = (1 << shift) - 1;
146 	int i, k, idx;
147 	u64 cur = 0;
148 	u64 base;
149 	int len;
150 	struct scatterlist *sg;
151 	int entry;
152 
153 	if (umem->is_odp) {
154 		WARN_ON(shift != 0);
155 		WARN_ON(access_flags != (MLX5_IB_MTT_READ | MLX5_IB_MTT_WRITE));
156 
157 		for (i = 0; i < num_pages; ++i) {
158 			dma_addr_t pa =
159 				to_ib_umem_odp(umem)->dma_list[offset + i];
160 
161 			pas[i] = cpu_to_be64(umem_dma_to_mtt(pa));
162 		}
163 		return;
164 	}
165 
166 	i = 0;
167 	for_each_sg(umem->sg_head.sgl, sg, umem->nmap, entry) {
168 		len = sg_dma_len(sg) >> PAGE_SHIFT;
169 		base = sg_dma_address(sg);
170 
171 		/* Skip elements below offset */
172 		if (i + len < offset << shift) {
173 			i += len;
174 			continue;
175 		}
176 
177 		/* Skip pages below offset */
178 		if (i < offset << shift) {
179 			k = (offset << shift) - i;
180 			i = offset << shift;
181 		} else {
182 			k = 0;
183 		}
184 
185 		for (; k < len; k++) {
186 			if (!(i & mask)) {
187 				cur = base + (k << PAGE_SHIFT);
188 				cur |= access_flags;
189 				idx = (i >> shift) - offset;
190 
191 				pas[idx] = cpu_to_be64(cur);
192 				mlx5_ib_dbg(dev, "pas[%d] 0x%llx\n",
193 					    i >> shift, be64_to_cpu(pas[idx]));
194 			}
195 			i++;
196 
197 			/* Stop after num_pages reached */
198 			if (i >> shift >= offset + num_pages)
199 				return;
200 		}
201 	}
202 }
203 
204 void mlx5_ib_populate_pas(struct mlx5_ib_dev *dev, struct ib_umem *umem,
205 			  int page_shift, __be64 *pas, int access_flags)
206 {
207 	return __mlx5_ib_populate_pas(dev, umem, page_shift, 0,
208 				      ib_umem_num_pages(umem), pas,
209 				      access_flags);
210 }
211 int mlx5_ib_get_buf_offset(u64 addr, int page_shift, u32 *offset)
212 {
213 	u64 page_size;
214 	u64 page_mask;
215 	u64 off_size;
216 	u64 off_mask;
217 	u64 buf_off;
218 
219 	page_size = (u64)1 << page_shift;
220 	page_mask = page_size - 1;
221 	buf_off = addr & page_mask;
222 	off_size = page_size >> 6;
223 	off_mask = off_size - 1;
224 
225 	if (buf_off & off_mask)
226 		return -EINVAL;
227 
228 	*offset = buf_off >> ilog2(off_size);
229 	return 0;
230 }
231