mlx4: add MOFED 3.0 compatibility to interface name retrieval

Since Mellanox OFED 3.0 and Linux 3.15, interface port numbers are stored
in dev_port instead of dev_id sysfs files.

Signed-off-by: Or Ami <ora@mellanox.com>
Signed-off-by: Nitzan Weller <nitzanwe@mellanox.com>
Signed-off-by: Adrien Mazarguil <adrien.mazarguil@6wind.com>

diff --git a/drivers/net/mlx4/mlx4.c b/drivers/net/mlx4/mlx4.c
index d1166b2..ad37e01 100644 (file)
--- a/drivers/net/mlx4/mlx4.c
+++ b/drivers/net/mlx4/mlx4.c
@@ -337,9 +337,11 @@ priv_unlock(struct priv *priv)
 static int
 priv_get_ifname(const struct priv *priv, char (*ifname)[IF_NAMESIZE])
 {
-       int ret = -1;
        DIR *dir;
        struct dirent *dent;
+       unsigned int dev_type = 0;
+       unsigned int dev_port_prev = ~0u;
+       char match[IF_NAMESIZE] = "";
 
        {
                MKSTR(path, "%s/device/net", priv->ctx->device->ibdev_path);
@@ -351,7 +353,7 @@ priv_get_ifname(const struct priv *priv, char (*ifname)[IF_NAMESIZE])
        while ((dent = readdir(dir)) != NULL) {
                char *name = dent->d_name;
                FILE *file;
-               unsigned int dev_id;
+               unsigned int dev_port;
                int r;
 
                if ((name[0] == '.') &&
@@ -359,22 +361,47 @@ priv_get_ifname(const struct priv *priv, char (*ifname)[IF_NAMESIZE])
                     ((name[1] == '.') && (name[2] == '\0'))))
                        continue;
 
-               MKSTR(path, "%s/device/net/%s/dev_id",
-                     priv->ctx->device->ibdev_path, name);
+               MKSTR(path, "%s/device/net/%s/%s",
+                     priv->ctx->device->ibdev_path, name,
+                     (dev_type ? "dev_id" : "dev_port"));
 
                file = fopen(path, "rb");
-               if (file == NULL)
+               if (file == NULL) {
+                       if (errno != ENOENT)
+                               continue;
+                       /*
+                        * Switch to dev_id when dev_port does not exist as
+                        * is the case with Linux kernel versions < 3.15.
+                        */
+try_dev_id:
+                       match[0] = '\0';
+                       if (dev_type)
+                               break;
+                       dev_type = 1;
+                       dev_port_prev = ~0u;
+                       rewinddir(dir);
                        continue;
-               r = fscanf(file, "%x", &dev_id);
-               fclose(file);
-               if ((r == 1) && (dev_id == (priv->port - 1u))) {
-                       snprintf(*ifname, sizeof(*ifname), "%s", name);
-                       ret = 0;
-                       break;
                }
+               r = fscanf(file, (dev_type ? "%x" : "%u"), &dev_port);
+               fclose(file);
+               if (r != 1)
+                       continue;
+               /*
+                * Switch to dev_id when dev_port returns the same value for
+                * all ports. May happen when using a MOFED release older than
+                * 3.0 with a Linux kernel >= 3.15.
+                */
+               if (dev_port == dev_port_prev)
+                       goto try_dev_id;
+               dev_port_prev = dev_port;
+               if (dev_port == (priv->port - 1u))
+                       snprintf(match, sizeof(match), "%s", name);
        }
        closedir(dir);
-       return ret;
+       if (match[0] == '\0')
+               return -1;
+       strncpy(*ifname, match, sizeof(*ifname));
+       return 0;
 }
 
 /**