xref: /openbmc/linux/drivers/infiniband/hw/mlx5/mem.c (revision 4da722ca19f30f7db250db808d1ab1703607a932)
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 	int i, k;
54 	u64 base = 0;
55 	int p = 0;
56 	int skip;
57 	int mask;
58 	u64 len;
59 	u64 pfn;
60 	struct scatterlist *sg;
61 	int entry;
62 	unsigned long page_shift = umem->page_shift;
63 
64 	if (umem->odp_data) {
65 		*ncont = ib_umem_page_count(umem);
66 		*count = *ncont << (page_shift - PAGE_SHIFT);
67 		*shift = page_shift;
68 		if (order)
69 			*order = ilog2(roundup_pow_of_two(*ncont));
70 
71 		return;
72 	}
73 
74 	addr = addr >> page_shift;
75 	tmp = (unsigned long)addr;
76 	m = find_first_bit(&tmp, BITS_PER_LONG);
77 	if (max_page_shift)
78 		m = min_t(unsigned long, max_page_shift - page_shift, m);
79 	skip = 1 << m;
80 	mask = skip - 1;
81 	i = 0;
82 	for_each_sg(umem->sg_head.sgl, sg, umem->nmap, entry) {
83 		len = sg_dma_len(sg) >> page_shift;
84 		pfn = sg_dma_address(sg) >> page_shift;
85 		for (k = 0; k < len; k++) {
86 			if (!(i & mask)) {
87 				tmp = (unsigned long)pfn;
88 				m = min_t(unsigned long, m, find_first_bit(&tmp, BITS_PER_LONG));
89 				skip = 1 << m;
90 				mask = skip - 1;
91 				base = pfn;
92 				p = 0;
93 			} else {
94 				if (base + p != pfn) {
95 					tmp = (unsigned long)p;
96 					m = find_first_bit(&tmp, BITS_PER_LONG);
97 					skip = 1 << m;
98 					mask = skip - 1;
99 					base = pfn;
100 					p = 0;
101 				}
102 			}
103 			p++;
104 			i++;
105 		}
106 	}
107 
108 	if (i) {
109 		m = min_t(unsigned long, ilog2(roundup_pow_of_two(i)), m);
110 
111 		if (order)
112 			*order = ilog2(roundup_pow_of_two(i) >> m);
113 
114 		*ncont = DIV_ROUND_UP(i, (1 << m));
115 	} else {
116 		m  = 0;
117 
118 		if (order)
119 			*order = 0;
120 
121 		*ncont = 0;
122 	}
123 	*shift = page_shift + m;
124 	*count = i;
125 }
126 
127 #ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
128 static u64 umem_dma_to_mtt(dma_addr_t umem_dma)
129 {
130 	u64 mtt_entry = umem_dma & ODP_DMA_ADDR_MASK;
131 
132 	if (umem_dma & ODP_READ_ALLOWED_BIT)
133 		mtt_entry |= MLX5_IB_MTT_READ;
134 	if (umem_dma & ODP_WRITE_ALLOWED_BIT)
135 		mtt_entry |= MLX5_IB_MTT_WRITE;
136 
137 	return mtt_entry;
138 }
139 #endif
140 
141 /*
142  * Populate the given array with bus addresses from the umem.
143  *
144  * dev - mlx5_ib device
145  * umem - umem to use to fill the pages
146  * page_shift - determines the page size used in the resulting array
147  * offset - offset into the umem to start from,
148  *          only implemented for ODP umems
149  * num_pages - total number of pages to fill
150  * pas - bus addresses array to fill
151  * access_flags - access flags to set on all present pages.
152 		  use enum mlx5_ib_mtt_access_flags for this.
153  */
154 void __mlx5_ib_populate_pas(struct mlx5_ib_dev *dev, struct ib_umem *umem,
155 			    int page_shift, size_t offset, size_t num_pages,
156 			    __be64 *pas, int access_flags)
157 {
158 	unsigned long umem_page_shift = umem->page_shift;
159 	int shift = page_shift - umem_page_shift;
160 	int mask = (1 << shift) - 1;
161 	int i, k, idx;
162 	u64 cur = 0;
163 	u64 base;
164 	int len;
165 	struct scatterlist *sg;
166 	int entry;
167 #ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
168 	const bool odp = umem->odp_data != NULL;
169 
170 	if (odp) {
171 		WARN_ON(shift != 0);
172 		WARN_ON(access_flags != (MLX5_IB_MTT_READ | MLX5_IB_MTT_WRITE));
173 
174 		for (i = 0; i < num_pages; ++i) {
175 			dma_addr_t pa = umem->odp_data->dma_list[offset + i];
176 
177 			pas[i] = cpu_to_be64(umem_dma_to_mtt(pa));
178 		}
179 		return;
180 	}
181 #endif
182 
183 	i = 0;
184 	for_each_sg(umem->sg_head.sgl, sg, umem->nmap, entry) {
185 		len = sg_dma_len(sg) >> umem_page_shift;
186 		base = sg_dma_address(sg);
187 
188 		/* Skip elements below offset */
189 		if (i + len < offset << shift) {
190 			i += len;
191 			continue;
192 		}
193 
194 		/* Skip pages below offset */
195 		if (i < offset << shift) {
196 			k = (offset << shift) - i;
197 			i = offset << shift;
198 		} else {
199 			k = 0;
200 		}
201 
202 		for (; k < len; k++) {
203 			if (!(i & mask)) {
204 				cur = base + (k << umem_page_shift);
205 				cur |= access_flags;
206 				idx = (i >> shift) - offset;
207 
208 				pas[idx] = cpu_to_be64(cur);
209 				mlx5_ib_dbg(dev, "pas[%d] 0x%llx\n",
210 					    i >> shift, be64_to_cpu(pas[idx]));
211 			}
212 			i++;
213 
214 			/* Stop after num_pages reached */
215 			if (i >> shift >= offset + num_pages)
216 				return;
217 		}
218 	}
219 }
220 
221 void mlx5_ib_populate_pas(struct mlx5_ib_dev *dev, struct ib_umem *umem,
222 			  int page_shift, __be64 *pas, int access_flags)
223 {
224 	return __mlx5_ib_populate_pas(dev, umem, page_shift, 0,
225 				      ib_umem_num_pages(umem), pas,
226 				      access_flags);
227 }
228 int mlx5_ib_get_buf_offset(u64 addr, int page_shift, u32 *offset)
229 {
230 	u64 page_size;
231 	u64 page_mask;
232 	u64 off_size;
233 	u64 off_mask;
234 	u64 buf_off;
235 
236 	page_size = (u64)1 << page_shift;
237 	page_mask = page_size - 1;
238 	buf_off = addr & page_mask;
239 	off_size = page_size >> 6;
240 	off_mask = off_size - 1;
241 
242 	if (buf_off & off_mask)
243 		return -EINVAL;
244 
245 	*offset = buf_off >> ilog2(off_size);
246 	return 0;
247 }
248