drivers/common/mlx5/mlx5_common.c

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright 2019 Mellanox Technologies, Ltd
   3  */
   4
   5 #include <dlfcn.h>
   6 #include <unistd.h>
   7 #include <string.h>
   8 #include <stdio.h>
   9
  10 #include <rte_errno.h>
  11
  12 #include "mlx5_common.h"
  13 #include "mlx5_common_utils.h"
  14 #include "mlx5_glue.h"
  15
  16
  17 int mlx5_common_logtype;
  18
  19
  20 /**
  21  * Get PCI information by sysfs device path.
  22  *
  23  * @param dev_path
  24  *   Pointer to device sysfs folder name.
  25  * @param[out] pci_addr
  26  *   PCI bus address output buffer.
  27  *
  28  * @return
  29  *   0 on success, a negative errno value otherwise and rte_errno is set.
  30  */
  31 int
  32 mlx5_dev_to_pci_addr(const char *dev_path,
  33                      struct rte_pci_addr *pci_addr)
  34 {
  35         FILE *file;
  36         char line[32];
  37         MKSTR(path, "%s/device/uevent", dev_path);
  38
  39         file = fopen(path, "rb");
  40         if (file == NULL) {
  41                 rte_errno = errno;
  42                 return -rte_errno;
  43         }
  44         while (fgets(line, sizeof(line), file) == line) {
  45                 size_t len = strlen(line);
  46                 int ret;
  47
  48                 /* Truncate long lines. */
  49                 if (len == (sizeof(line) - 1))
  50                         while (line[(len - 1)] != '\n') {
  51                                 ret = fgetc(file);
  52                                 if (ret == EOF)
  53                                         break;
  54                                 line[(len - 1)] = ret;
  55                         }
  56                 /* Extract information. */
  57                 if (sscanf(line,
  58                            "PCI_SLOT_NAME="
  59                            "%" SCNx32 ":%" SCNx8 ":%" SCNx8 ".%" SCNx8 "\n",
  60                            &pci_addr->domain,
  61                            &pci_addr->bus,
  62                            &pci_addr->devid,
  63                            &pci_addr->function) == 4) {
  64                         ret = 0;
  65                         break;
  66                 }
  67         }
  68         fclose(file);
  69         return 0;
  70 }
  71
  72 #ifdef RTE_IBVERBS_LINK_DLOPEN
  73
  74 /**
  75  * Suffix RTE_EAL_PMD_PATH with "-glue".
  76  *
  77  * This function performs a sanity check on RTE_EAL_PMD_PATH before
  78  * suffixing its last component.
  79  *
  80  * @param buf[out]
  81  *   Output buffer, should be large enough otherwise NULL is returned.
  82  * @param size
  83  *   Size of @p out.
  84  *
  85  * @return
  86  *   Pointer to @p buf or @p NULL in case suffix cannot be appended.
  87  */
  88 static char *
  89 mlx5_glue_path(char *buf, size_t size)
  90 {
  91         static const char *const bad[] = { "/", ".", "..", NULL };
  92         const char *path = RTE_EAL_PMD_PATH;
  93         size_t len = strlen(path);
  94         size_t off;
  95         int i;
  96
  97         while (len && path[len - 1] == '/')
  98                 --len;
  99         for (off = len; off && path[off - 1] != '/'; --off)
 100                 ;
 101         for (i = 0; bad[i]; ++i)
 102                 if (!strncmp(path + off, bad[i], (int)(len - off)))
 103                         goto error;
 104         i = snprintf(buf, size, "%.*s-glue", (int)len, path);
 105         if (i == -1 || (size_t)i >= size)
 106                 goto error;
 107         return buf;
 108 error:
 109         RTE_LOG(ERR, PMD, "unable to append \"-glue\" to last component of"
 110                 " RTE_EAL_PMD_PATH (\"" RTE_EAL_PMD_PATH "\"), please"
 111                 " re-configure DPDK");
 112         return NULL;
 113 }
 114 #endif
 115
 116 /**
 117  * Initialization routine for run-time dependency on rdma-core.
 118  */
 119 RTE_INIT_PRIO(mlx5_glue_init, CLASS)
 120 {
 121         void *handle = NULL;
 122
 123         /* Initialize common log type. */
 124         mlx5_common_logtype = rte_log_register("pmd.common.mlx5");
 125         if (mlx5_common_logtype >= 0)
 126                 rte_log_set_level(mlx5_common_logtype, RTE_LOG_NOTICE);
 127         /*
 128          * RDMAV_HUGEPAGES_SAFE tells ibv_fork_init() we intend to use
 129          * huge pages. Calling ibv_fork_init() during init allows
 130          * applications to use fork() safely for purposes other than
 131          * using this PMD, which is not supported in forked processes.
 132          */
 133         setenv("RDMAV_HUGEPAGES_SAFE", "1", 1);
 134         /* Match the size of Rx completion entry to the size of a cacheline. */
 135         if (RTE_CACHE_LINE_SIZE == 128)
 136                 setenv("MLX5_CQE_SIZE", "128", 0);
 137         /*
 138          * MLX5_DEVICE_FATAL_CLEANUP tells ibv_destroy functions to
 139          * cleanup all the Verbs resources even when the device was removed.
 140          */
 141         setenv("MLX5_DEVICE_FATAL_CLEANUP", "1", 1);
 142         /* The glue initialization was done earlier by mlx5 common library. */
 143 #ifdef RTE_IBVERBS_LINK_DLOPEN
 144         char glue_path[sizeof(RTE_EAL_PMD_PATH) - 1 + sizeof("-glue")];
 145         const char *path[] = {
 146                 /*
 147                  * A basic security check is necessary before trusting
 148                  * MLX5_GLUE_PATH, which may override RTE_EAL_PMD_PATH.
 149                  */
 150                 (geteuid() == getuid() && getegid() == getgid() ?
 151                  getenv("MLX5_GLUE_PATH") : NULL),
 152                 /*
 153                  * When RTE_EAL_PMD_PATH is set, use its glue-suffixed
 154                  * variant, otherwise let dlopen() look up libraries on its
 155                  * own.
 156                  */
 157                 (*RTE_EAL_PMD_PATH ?
 158                  mlx5_glue_path(glue_path, sizeof(glue_path)) : ""),
 159         };
 160         unsigned int i = 0;
 161         void **sym;
 162         const char *dlmsg;
 163
 164         while (!handle && i != RTE_DIM(path)) {
 165                 const char *end;
 166                 size_t len;
 167                 int ret;
 168
 169                 if (!path[i]) {
 170                         ++i;
 171                         continue;
 172                 }
 173                 end = strpbrk(path[i], ":;");
 174                 if (!end)
 175                         end = path[i] + strlen(path[i]);
 176                 len = end - path[i];
 177                 ret = 0;
 178                 do {
 179                         char name[ret + 1];
 180
 181                         ret = snprintf(name, sizeof(name), "%.*s%s" MLX5_GLUE,
 182                                        (int)len, path[i],
 183                                        (!len || *(end - 1) == '/') ? "" : "/");
 184                         if (ret == -1)
 185                                 break;
 186                         if (sizeof(name) != (size_t)ret + 1)
 187                                 continue;
 188                         DRV_LOG(DEBUG, "Looking for rdma-core glue as "
 189                                 "\"%s\"", name);
 190                         handle = dlopen(name, RTLD_LAZY);
 191                         break;
 192                 } while (1);
 193                 path[i] = end + 1;
 194                 if (!*end)
 195                         ++i;
 196         }
 197         if (!handle) {
 198                 rte_errno = EINVAL;
 199                 dlmsg = dlerror();
 200                 if (dlmsg)
 201                         DRV_LOG(WARNING, "Cannot load glue library: %s", dlmsg);
 202                 goto glue_error;
 203         }
 204         sym = dlsym(handle, "mlx5_glue");
 205         if (!sym || !*sym) {
 206                 rte_errno = EINVAL;
 207                 dlmsg = dlerror();
 208                 if (dlmsg)
 209                         DRV_LOG(ERR, "Cannot resolve glue symbol: %s", dlmsg);
 210                 goto glue_error;
 211         }
 212         mlx5_glue = *sym;
 213 #endif /* RTE_IBVERBS_LINK_DLOPEN */
 214 #ifndef NDEBUG
 215         /* Glue structure must not contain any NULL pointers. */
 216         {
 217                 unsigned int i;
 218
 219                 for (i = 0; i != sizeof(*mlx5_glue) / sizeof(void *); ++i)
 220                         assert(((const void *const *)mlx5_glue)[i]);
 221         }
 222 #endif
 223         if (strcmp(mlx5_glue->version, MLX5_GLUE_VERSION)) {
 224                 rte_errno = EINVAL;
 225                 DRV_LOG(ERR, "rdma-core glue \"%s\" mismatch: \"%s\" is "
 226                         "required", mlx5_glue->version, MLX5_GLUE_VERSION);
 227                 goto glue_error;
 228         }
 229         mlx5_glue->fork_init();
 230         return;
 231 glue_error:
 232         if (handle)
 233                 dlclose(handle);
 234         DRV_LOG(WARNING, "Cannot initialize MLX5 common due to missing"
 235                 " run-time dependency on rdma-core libraries (libibverbs,"
 236                 " libmlx5)");
 237         mlx5_glue = NULL;
 238         return;
 239 }