xref: /dpdk/drivers/common/mlx5/linux/mlx5_common_os.c (revision 262c7ad0dd745251ca5a4cf8dc18fbde3123c3cc)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright 2020 Mellanox Technologies, Ltd
3  */
4 
5 #include <unistd.h>
6 #include <string.h>
7 #include <stdio.h>
8 #ifdef RTE_IBVERBS_LINK_DLOPEN
9 #include <dlfcn.h>
10 #endif
11 #include <dirent.h>
12 #include <net/if.h>
13 
14 #include <rte_errno.h>
15 #include <rte_string_fns.h>
16 
17 #include "mlx5_common.h"
18 #include "mlx5_common_utils.h"
19 #include "mlx5_glue.h"
20 
21 #ifdef MLX5_GLUE
22 const struct mlx5_glue *mlx5_glue;
23 #endif
24 
25 /**
26  * Get PCI information by sysfs device path.
27  *
28  * @param dev_path
29  *   Pointer to device sysfs folder name.
30  * @param[out] pci_addr
31  *   PCI bus address output buffer.
32  *
33  * @return
34  *   0 on success, a negative errno value otherwise and rte_errno is set.
35  */
36 int
37 mlx5_dev_to_pci_addr(const char *dev_path,
38 		     struct rte_pci_addr *pci_addr)
39 {
40 	FILE *file;
41 	char line[32];
42 	MKSTR(path, "%s/device/uevent", dev_path);
43 
44 	file = fopen(path, "rb");
45 	if (file == NULL) {
46 		rte_errno = errno;
47 		return -rte_errno;
48 	}
49 	while (fgets(line, sizeof(line), file) == line) {
50 		size_t len = strlen(line);
51 		int ret;
52 
53 		/* Truncate long lines. */
54 		if (len == (sizeof(line) - 1))
55 			while (line[(len - 1)] != '\n') {
56 				ret = fgetc(file);
57 				if (ret == EOF)
58 					break;
59 				line[(len - 1)] = ret;
60 			}
61 		/* Extract information. */
62 		if (sscanf(line,
63 			   "PCI_SLOT_NAME="
64 			   "%" SCNx32 ":%" SCNx8 ":%" SCNx8 ".%" SCNx8 "\n",
65 			   &pci_addr->domain,
66 			   &pci_addr->bus,
67 			   &pci_addr->devid,
68 			   &pci_addr->function) == 4) {
69 			ret = 0;
70 			break;
71 		}
72 	}
73 	fclose(file);
74 	return 0;
75 }
76 
77 /**
78  * Extract port name, as a number, from sysfs or netlink information.
79  *
80  * @param[in] port_name_in
81  *   String representing the port name.
82  * @param[out] port_info_out
83  *   Port information, including port name as a number and port name
84  *   type if recognized
85  *
86  * @return
87  *   port_name field set according to recognized name format.
88  */
89 void
90 mlx5_translate_port_name(const char *port_name_in,
91 			 struct mlx5_switch_info *port_info_out)
92 {
93 	char pf_c1, pf_c2, vf_c1, vf_c2;
94 	char *end;
95 	int sc_items;
96 
97 	/*
98 	 * Check for port-name as a string of the form pf0vf0
99 	 * (support kernel ver >= 5.0 or OFED ver >= 4.6).
100 	 */
101 	sc_items = sscanf(port_name_in, "%c%c%d%c%c%d",
102 			  &pf_c1, &pf_c2, &port_info_out->pf_num,
103 			  &vf_c1, &vf_c2, &port_info_out->port_name);
104 	if (sc_items == 6 &&
105 	    pf_c1 == 'p' && pf_c2 == 'f' &&
106 	    vf_c1 == 'v' && vf_c2 == 'f') {
107 		port_info_out->name_type = MLX5_PHYS_PORT_NAME_TYPE_PFVF;
108 		return;
109 	}
110 	/*
111 	 * Check for port-name as a string of the form p0
112 	 * (support kernel ver >= 5.0, or OFED ver >= 4.6).
113 	 */
114 	sc_items = sscanf(port_name_in, "%c%d",
115 			  &pf_c1, &port_info_out->port_name);
116 	if (sc_items == 2 && pf_c1 == 'p') {
117 		port_info_out->name_type = MLX5_PHYS_PORT_NAME_TYPE_UPLINK;
118 		return;
119 	}
120 	/* Check for port-name as a number (support kernel ver < 5.0 */
121 	errno = 0;
122 	port_info_out->port_name = strtol(port_name_in, &end, 0);
123 	if (!errno &&
124 	    (size_t)(end - port_name_in) == strlen(port_name_in)) {
125 		port_info_out->name_type = MLX5_PHYS_PORT_NAME_TYPE_LEGACY;
126 		return;
127 	}
128 	port_info_out->name_type = MLX5_PHYS_PORT_NAME_TYPE_UNKNOWN;
129 }
130 
131 /**
132  * Get kernel interface name from IB device path.
133  *
134  * @param[in] ibdev_path
135  *   Pointer to IB device path.
136  * @param[out] ifname
137  *   Interface name output buffer.
138  *
139  * @return
140  *   0 on success, a negative errno value otherwise and rte_errno is set.
141  */
142 int
143 mlx5_get_ifname_sysfs(const char *ibdev_path, char *ifname)
144 {
145 	DIR *dir;
146 	struct dirent *dent;
147 	unsigned int dev_type = 0;
148 	unsigned int dev_port_prev = ~0u;
149 	char match[IF_NAMESIZE] = "";
150 
151 	MLX5_ASSERT(ibdev_path);
152 	{
153 		MKSTR(path, "%s/device/net", ibdev_path);
154 
155 		dir = opendir(path);
156 		if (dir == NULL) {
157 			rte_errno = errno;
158 			return -rte_errno;
159 		}
160 	}
161 	while ((dent = readdir(dir)) != NULL) {
162 		char *name = dent->d_name;
163 		FILE *file;
164 		unsigned int dev_port;
165 		int r;
166 
167 		if ((name[0] == '.') &&
168 		    ((name[1] == '\0') ||
169 		     ((name[1] == '.') && (name[2] == '\0'))))
170 			continue;
171 
172 		MKSTR(path, "%s/device/net/%s/%s",
173 		      ibdev_path, name,
174 		      (dev_type ? "dev_id" : "dev_port"));
175 
176 		file = fopen(path, "rb");
177 		if (file == NULL) {
178 			if (errno != ENOENT)
179 				continue;
180 			/*
181 			 * Switch to dev_id when dev_port does not exist as
182 			 * is the case with Linux kernel versions < 3.15.
183 			 */
184 try_dev_id:
185 			match[0] = '\0';
186 			if (dev_type)
187 				break;
188 			dev_type = 1;
189 			dev_port_prev = ~0u;
190 			rewinddir(dir);
191 			continue;
192 		}
193 		r = fscanf(file, (dev_type ? "%x" : "%u"), &dev_port);
194 		fclose(file);
195 		if (r != 1)
196 			continue;
197 		/*
198 		 * Switch to dev_id when dev_port returns the same value for
199 		 * all ports. May happen when using a MOFED release older than
200 		 * 3.0 with a Linux kernel >= 3.15.
201 		 */
202 		if (dev_port == dev_port_prev)
203 			goto try_dev_id;
204 		dev_port_prev = dev_port;
205 		if (dev_port == 0)
206 			strlcpy(match, name, IF_NAMESIZE);
207 	}
208 	closedir(dir);
209 	if (match[0] == '\0') {
210 		rte_errno = ENOENT;
211 		return -rte_errno;
212 	}
213 	strncpy(ifname, match, IF_NAMESIZE);
214 	return 0;
215 }
216 
217 #ifdef MLX5_GLUE
218 
219 /**
220  * Suffix RTE_EAL_PMD_PATH with "-glue".
221  *
222  * This function performs a sanity check on RTE_EAL_PMD_PATH before
223  * suffixing its last component.
224  *
225  * @param buf[out]
226  *   Output buffer, should be large enough otherwise NULL is returned.
227  * @param size
228  *   Size of @p out.
229  *
230  * @return
231  *   Pointer to @p buf or @p NULL in case suffix cannot be appended.
232  */
233 static char *
234 mlx5_glue_path(char *buf, size_t size)
235 {
236 	static const char *const bad[] = { "/", ".", "..", NULL };
237 	const char *path = RTE_EAL_PMD_PATH;
238 	size_t len = strlen(path);
239 	size_t off;
240 	int i;
241 
242 	while (len && path[len - 1] == '/')
243 		--len;
244 	for (off = len; off && path[off - 1] != '/'; --off)
245 		;
246 	for (i = 0; bad[i]; ++i)
247 		if (!strncmp(path + off, bad[i], (int)(len - off)))
248 			goto error;
249 	i = snprintf(buf, size, "%.*s-glue", (int)len, path);
250 	if (i == -1 || (size_t)i >= size)
251 		goto error;
252 	return buf;
253 error:
254 	RTE_LOG(ERR, PMD, "unable to append \"-glue\" to last component of"
255 		" RTE_EAL_PMD_PATH (\"" RTE_EAL_PMD_PATH "\"), please"
256 		" re-configure DPDK");
257 	return NULL;
258 }
259 
260 static int
261 mlx5_glue_dlopen(void)
262 {
263 	char glue_path[sizeof(RTE_EAL_PMD_PATH) - 1 + sizeof("-glue")];
264 	void *handle = NULL;
265 
266 	char const *path[] = {
267 		/*
268 		 * A basic security check is necessary before trusting
269 		 * MLX5_GLUE_PATH, which may override RTE_EAL_PMD_PATH.
270 		 */
271 		(geteuid() == getuid() && getegid() == getgid() ?
272 		 getenv("MLX5_GLUE_PATH") : NULL),
273 		/*
274 		 * When RTE_EAL_PMD_PATH is set, use its glue-suffixed
275 		 * variant, otherwise let dlopen() look up libraries on its
276 		 * own.
277 		 */
278 		(*RTE_EAL_PMD_PATH ?
279 		 mlx5_glue_path(glue_path, sizeof(glue_path)) : ""),
280 	};
281 	unsigned int i = 0;
282 	void **sym;
283 	const char *dlmsg;
284 
285 	while (!handle && i != RTE_DIM(path)) {
286 		const char *end;
287 		size_t len;
288 		int ret;
289 
290 		if (!path[i]) {
291 			++i;
292 			continue;
293 		}
294 		end = strpbrk(path[i], ":;");
295 		if (!end)
296 			end = path[i] + strlen(path[i]);
297 		len = end - path[i];
298 		ret = 0;
299 		do {
300 			char name[ret + 1];
301 
302 			ret = snprintf(name, sizeof(name), "%.*s%s" MLX5_GLUE,
303 				       (int)len, path[i],
304 				       (!len || *(end - 1) == '/') ? "" : "/");
305 			if (ret == -1)
306 				break;
307 			if (sizeof(name) != (size_t)ret + 1)
308 				continue;
309 			DRV_LOG(DEBUG, "Looking for rdma-core glue as "
310 				"\"%s\"", name);
311 			handle = dlopen(name, RTLD_LAZY);
312 			break;
313 		} while (1);
314 		path[i] = end + 1;
315 		if (!*end)
316 			++i;
317 	}
318 	if (!handle) {
319 		rte_errno = EINVAL;
320 		dlmsg = dlerror();
321 		if (dlmsg)
322 			DRV_LOG(WARNING, "Cannot load glue library: %s", dlmsg);
323 		goto glue_error;
324 	}
325 	sym = dlsym(handle, "mlx5_glue");
326 	if (!sym || !*sym) {
327 		rte_errno = EINVAL;
328 		dlmsg = dlerror();
329 		if (dlmsg)
330 			DRV_LOG(ERR, "Cannot resolve glue symbol: %s", dlmsg);
331 		goto glue_error;
332 	}
333 	mlx5_glue = *sym;
334 	return 0;
335 
336 glue_error:
337 	if (handle)
338 		dlclose(handle);
339 	return -1;
340 }
341 
342 #endif
343 
344 /**
345  * Initialization routine for run-time dependency on rdma-core.
346  */
347 void
348 mlx5_glue_constructor(void)
349 {
350 	/*
351 	 * RDMAV_HUGEPAGES_SAFE tells ibv_fork_init() we intend to use
352 	 * huge pages. Calling ibv_fork_init() during init allows
353 	 * applications to use fork() safely for purposes other than
354 	 * using this PMD, which is not supported in forked processes.
355 	 */
356 	setenv("RDMAV_HUGEPAGES_SAFE", "1", 1);
357 	/* Match the size of Rx completion entry to the size of a cacheline. */
358 	if (RTE_CACHE_LINE_SIZE == 128)
359 		setenv("MLX5_CQE_SIZE", "128", 0);
360 	/*
361 	 * MLX5_DEVICE_FATAL_CLEANUP tells ibv_destroy functions to
362 	 * cleanup all the Verbs resources even when the device was removed.
363 	 */
364 	setenv("MLX5_DEVICE_FATAL_CLEANUP", "1", 1);
365 
366 #ifdef MLX5_GLUE
367 	if (mlx5_glue_dlopen() != 0)
368 		goto glue_error;
369 #endif
370 
371 #ifdef RTE_LIBRTE_MLX5_DEBUG
372 	/* Glue structure must not contain any NULL pointers. */
373 	{
374 		unsigned int i;
375 
376 		for (i = 0; i != sizeof(*mlx5_glue) / sizeof(void *); ++i)
377 			MLX5_ASSERT(((const void *const *)mlx5_glue)[i]);
378 	}
379 #endif
380 	if (strcmp(mlx5_glue->version, MLX5_GLUE_VERSION)) {
381 		rte_errno = EINVAL;
382 		DRV_LOG(ERR, "rdma-core glue \"%s\" mismatch: \"%s\" is "
383 			"required", mlx5_glue->version, MLX5_GLUE_VERSION);
384 		goto glue_error;
385 	}
386 	mlx5_glue->fork_init();
387 	return;
388 
389 glue_error:
390 	DRV_LOG(WARNING, "Cannot initialize MLX5 common due to missing"
391 		" run-time dependency on rdma-core libraries (libibverbs,"
392 		" libmlx5)");
393 	mlx5_glue = NULL;
394 }
395 
396