1/*
2 * Copyright (c) 2017 Cisco and/or its affiliates.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at:
6 *
7 *     http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15
16#include <vppinfra/clib.h>
17#include <vppinfra/clib_error.h>
18#include <vppinfra/format.h>
19
20#include <sys/types.h>
21#include <sys/stat.h>
22#include <fcntl.h>
23#include <dirent.h>
24
25clib_error_t *
26clib_sysfs_write (char *file_name, char *fmt, ...)
27{
28  u8 *s;
29  int fd;
30  clib_error_t *error = 0;
31
32  fd = open (file_name, O_WRONLY);
33  if (fd < 0)
34    return clib_error_return_unix (0, "open `%s'", file_name);
35
36  va_list va;
37  va_start (va, fmt);
38  s = va_format (0, fmt, &va);
39  va_end (va);
40
41  if (write (fd, s, vec_len (s)) < 0)
42    error = clib_error_return_unix (0, "write `%s'", file_name);
43
44  vec_free (s);
45  close (fd);
46  return error;
47}
48
49clib_error_t *
50clib_sysfs_read (char *file_name, char *fmt, ...)
51{
52  unformat_input_t input;
53  u8 *s = 0;
54  int fd;
55  ssize_t sz;
56  uword result;
57
58  fd = open (file_name, O_RDONLY);
59  if (fd < 0)
60    return clib_error_return_unix (0, "open `%s'", file_name);
61
62  vec_validate (s, 4095);
63
64  sz = read (fd, s, vec_len (s));
65  if (sz < 0)
66    {
67      close (fd);
68      vec_free (s);
69      return clib_error_return_unix (0, "read `%s'", file_name);
70    }
71
72  _vec_len (s) = sz;
73  unformat_init_vector (&input, s);
74
75  va_list va;
76  va_start (va, fmt);
77  result = va_unformat (&input, fmt, &va);
78  va_end (va);
79
80  vec_free (s);
81  close (fd);
82
83  if (result == 0)
84    return clib_error_return (0, "unformat error");
85
86  return 0;
87}
88
89u8 *
90clib_sysfs_link_to_name (char *link)
91{
92  char *p, buffer[64];
93  unformat_input_t in;
94  u8 *s = 0;
95  int r;
96
97  r = readlink (link, buffer, sizeof (buffer) - 1);
98
99  if (r < 0)
100    return 0;
101
102  buffer[r] = 0;
103  p = strrchr (buffer, '/');
104
105  if (!p)
106    return 0;
107
108  unformat_init_string (&in, p + 1, strlen (p + 1));
109  if (unformat (&in, "%s", &s) != 1)
110    clib_unix_warning ("no string?");
111  unformat_free (&in);
112
113  return s;
114}
115
116clib_error_t *
117clib_sysfs_set_nr_hugepages (int numa_node, int log2_page_size, int nr)
118{
119  clib_error_t *error = 0;
120  struct stat sb;
121  u8 *p = 0;
122  uword page_size;
123
124  if (log2_page_size == 0)
125    log2_page_size = min_log2 (clib_mem_get_default_hugepage_size ());
126
127  page_size = 1ULL << (log2_page_size - 10);
128
129  p = format (p, "/sys/devices/system/node/node%u%c", numa_node, 0);
130
131  if (stat ((char *) p, &sb) == 0)
132    {
133      if (S_ISDIR (sb.st_mode) == 0)
134	{
135	  error = clib_error_return (0, "'%s' is not directory", p);
136	  goto done;
137	}
138    }
139  else if (numa_node == 0)
140    {
141      vec_reset_length (p);
142      p = format (p, "/sys/kernel/mm%c", 0);
143      if (stat ((char *) p, &sb) < 0 || S_ISDIR (sb.st_mode) == 0)
144	{
145	  error = clib_error_return (0, "'%s' does not exist or it is not "
146				     "directory", p);
147	  goto done;
148	}
149    }
150  else
151    {
152      error = clib_error_return (0, "'%s' does not exist", p);
153      goto done;
154    }
155
156  _vec_len (p) -= 1;
157  p = format (p, "/hugepages/hugepages-%ukB/nr_hugepages%c", page_size, 0);
158  clib_sysfs_write ((char *) p, "%d", nr);
159
160done:
161  vec_free (p);
162  return error;
163}
164
165
166static clib_error_t *
167clib_sysfs_get_xxx_hugepages (char *type, int numa_node,
168			      int log2_page_size, int *val)
169{
170  clib_error_t *error = 0;
171  struct stat sb;
172  u8 *p = 0;
173
174  uword page_size;
175
176  if (log2_page_size == 0)
177    log2_page_size = min_log2 (clib_mem_get_default_hugepage_size ());
178
179  page_size = 1ULL << (log2_page_size - 10);
180
181
182  p = format (p, "/sys/devices/system/node/node%u%c", numa_node, 0);
183
184  if (stat ((char *) p, &sb) == 0)
185    {
186      if (S_ISDIR (sb.st_mode) == 0)
187	{
188	  error = clib_error_return (0, "'%s' is not directory", p);
189	  goto done;
190	}
191    }
192  else if (numa_node == 0)
193    {
194      vec_reset_length (p);
195      p = format (p, "/sys/kernel/mm%c", 0);
196      if (stat ((char *) p, &sb) < 0 || S_ISDIR (sb.st_mode) == 0)
197	{
198	  error = clib_error_return (0, "'%s' does not exist or it is not "
199				     "directory", p);
200	  goto done;
201	}
202    }
203  else
204    {
205      error = clib_error_return (0, "'%s' does not exist", p);
206      goto done;
207    }
208
209  _vec_len (p) -= 1;
210  p = format (p, "/hugepages/hugepages-%ukB/%s_hugepages%c", page_size,
211	      type, 0);
212  error = clib_sysfs_read ((char *) p, "%d", val);
213
214done:
215  vec_free (p);
216  return error;
217}
218
219clib_error_t *
220clib_sysfs_get_free_hugepages (int numa_node, int log2_page_size, int *v)
221{
222  return clib_sysfs_get_xxx_hugepages ("free", numa_node, log2_page_size, v);
223}
224
225clib_error_t *
226clib_sysfs_get_nr_hugepages (int numa_node, int log2_page_size, int *v)
227{
228  return clib_sysfs_get_xxx_hugepages ("nr", numa_node, log2_page_size, v);
229}
230
231clib_error_t *
232clib_sysfs_get_surplus_hugepages (int numa_node, int log2_page_size, int *v)
233{
234  return clib_sysfs_get_xxx_hugepages ("surplus", numa_node, log2_page_size,
235				       v);
236}
237
238clib_error_t *
239clib_sysfs_prealloc_hugepages (int numa_node, int log2_page_size, int nr)
240{
241  clib_error_t *error = 0;
242  int n, needed;
243  uword page_size;
244
245  if (log2_page_size == 0)
246    log2_page_size = min_log2 (clib_mem_get_default_hugepage_size ());
247
248  page_size = 1ULL << (log2_page_size - 10);
249
250  error = clib_sysfs_get_free_hugepages (numa_node, log2_page_size, &n);
251  if (error)
252    return error;
253  needed = nr - n;
254  if (needed <= 0)
255    return 0;
256
257  error = clib_sysfs_get_nr_hugepages (numa_node, log2_page_size, &n);
258  if (error)
259    return error;
260  clib_warning ("pre-allocating %u additional %uK hugepages on numa node %u",
261		needed, page_size, numa_node);
262  return clib_sysfs_set_nr_hugepages (numa_node, log2_page_size, n + needed);
263}
264
265
266/*
267 * fd.io coding-style-patch-verification: ON
268 *
269 * Local Variables:
270 * eval: (c-set-style "gnu")
271 * End:
272 */
273