xref: /linux/drivers/infiniband/hw/mlx5/mem.c (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
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 = ilog2(umem->page_size);
63 
64 	/* With ODP we must always match OS page size. */
65 	if (umem->odp_data) {
66 		*count = ib_umem_page_count(umem);
67 		*shift = PAGE_SHIFT;
68 		*ncont = *count;
69 		if (order)
70 			*order = ilog2(roundup_pow_of_two(*count));
71 
72 		return;
73 	}
74 
75 	addr = addr >> page_shift;
76 	tmp = (unsigned long)addr;
77 	m = find_first_bit(&tmp, BITS_PER_LONG);
78 	if (max_page_shift)
79 		m = min_t(unsigned long, max_page_shift - page_shift, m);
80 	skip = 1 << m;
81 	mask = skip - 1;
82 	i = 0;
83 	for_each_sg(umem->sg_head.sgl, sg, umem->nmap, entry) {
84 		len = sg_dma_len(sg) >> page_shift;
85 		pfn = sg_dma_address(sg) >> page_shift;
86 		for (k = 0; k < len; k++) {
87 			if (!(i & mask)) {
88 				tmp = (unsigned long)pfn;
89 				m = min_t(unsigned long, m, find_first_bit(&tmp, BITS_PER_LONG));
90 				skip = 1 << m;
91 				mask = skip - 1;
92 				base = pfn;
93 				p = 0;
94 			} else {
95 				if (base + p != pfn) {
96 					tmp = (unsigned long)p;
97 					m = find_first_bit(&tmp, BITS_PER_LONG);
98 					skip = 1 << m;
99 					mask = skip - 1;
100 					base = pfn;
101 					p = 0;
102 				}
103 			}
104 			p++;
105 			i++;
106 		}
107 	}
108 
109 	if (i) {
110 		m = min_t(unsigned long, ilog2(roundup_pow_of_two(i)), m);
111 
112 		if (order)
113 			*order = ilog2(roundup_pow_of_two(i) >> m);
114 
115 		*ncont = DIV_ROUND_UP(i, (1 << m));
116 	} else {
117 		m  = 0;
118 
119 		if (order)
120 			*order = 0;
121 
122 		*ncont = 0;
123 	}
124 	*shift = page_shift + m;
125 	*count = i;
126 }
127 
128 #ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
129 static u64 umem_dma_to_mtt(dma_addr_t umem_dma)
130 {
131 	u64 mtt_entry = umem_dma & ODP_DMA_ADDR_MASK;
132 
133 	if (umem_dma & ODP_READ_ALLOWED_BIT)
134 		mtt_entry |= MLX5_IB_MTT_READ;
135 	if (umem_dma & ODP_WRITE_ALLOWED_BIT)
136 		mtt_entry |= MLX5_IB_MTT_WRITE;
137 
138 	return mtt_entry;
139 }
140 #endif
141 
142 /*
143  * Populate the given array with bus addresses from the umem.
144  *
145  * dev - mlx5_ib device
146  * umem - umem to use to fill the pages
147  * page_shift - determines the page size used in the resulting array
148  * offset - offset into the umem to start from,
149  *          only implemented for ODP umems
150  * num_pages - total number of pages to fill
151  * pas - bus addresses array to fill
152  * access_flags - access flags to set on all present pages.
153 		  use enum mlx5_ib_mtt_access_flags for this.
154  */
155 void __mlx5_ib_populate_pas(struct mlx5_ib_dev *dev, struct ib_umem *umem,
156 			    int page_shift, size_t offset, size_t num_pages,
157 			    __be64 *pas, int access_flags)
158 {
159 	unsigned long umem_page_shift = ilog2(umem->page_size);
160 	int shift = page_shift - umem_page_shift;
161 	int mask = (1 << shift) - 1;
162 	int i, k, idx;
163 	u64 cur = 0;
164 	u64 base;
165 	int len;
166 	struct scatterlist *sg;
167 	int entry;
168 #ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
169 	const bool odp = umem->odp_data != NULL;
170 
171 	if (odp) {
172 		WARN_ON(shift != 0);
173 		WARN_ON(access_flags != (MLX5_IB_MTT_READ | MLX5_IB_MTT_WRITE));
174 
175 		for (i = 0; i < num_pages; ++i) {
176 			dma_addr_t pa = umem->odp_data->dma_list[offset + i];
177 
178 			pas[i] = cpu_to_be64(umem_dma_to_mtt(pa));
179 		}
180 		return;
181 	}
182 #endif
183 
184 	i = 0;
185 	for_each_sg(umem->sg_head.sgl, sg, umem->nmap, entry) {
186 		len = sg_dma_len(sg) >> umem_page_shift;
187 		base = sg_dma_address(sg);
188 
189 		/* Skip elements below offset */
190 		if (i + len < offset << shift) {
191 			i += len;
192 			continue;
193 		}
194 
195 		/* Skip pages below offset */
196 		if (i < offset << shift) {
197 			k = (offset << shift) - i;
198 			i = offset << shift;
199 		} else {
200 			k = 0;
201 		}
202 
203 		for (; k < len; k++) {
204 			if (!(i & mask)) {
205 				cur = base + (k << umem_page_shift);
206 				cur |= access_flags;
207 				idx = (i >> shift) - offset;
208 
209 				pas[idx] = cpu_to_be64(cur);
210 				mlx5_ib_dbg(dev, "pas[%d] 0x%llx\n",
211 					    i >> shift, be64_to_cpu(pas[idx]));
212 			}
213 			i++;
214 
215 			/* Stop after num_pages reached */
216 			if (i >> shift >= offset + num_pages)
217 				return;
218 		}
219 	}
220 }
221 
222 void mlx5_ib_populate_pas(struct mlx5_ib_dev *dev, struct ib_umem *umem,
223 			  int page_shift, __be64 *pas, int access_flags)
224 {
225 	return __mlx5_ib_populate_pas(dev, umem, page_shift, 0,
226 				      ib_umem_num_pages(umem), pas,
227 				      access_flags);
228 }
229 int mlx5_ib_get_buf_offset(u64 addr, int page_shift, u32 *offset)
230 {
231 	u64 page_size;
232 	u64 page_mask;
233 	u64 off_size;
234 	u64 off_mask;
235 	u64 buf_off;
236 
237 	page_size = (u64)1 << page_shift;
238 	page_mask = page_size - 1;
239 	buf_off = addr & page_mask;
240 	off_size = page_size >> 6;
241 	off_mask = off_size - 1;
242 
243 	if (buf_off & off_mask)
244 		return -EINVAL;
245 
246 	*offset = buf_off >> ilog2(off_size);
247 	return 0;
248 }
249