net/dsa/master.c

   1 /*
   2  * Handling of a master device, switching frames via its switch fabric CPU port
   3  *
   4  * Copyright (c) 2017 Savoir-faire Linux Inc.
   5  *      Vivien Didelot <vivien.didelot@savoirfairelinux.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  */
  12
  13 #include "dsa_priv.h"
  14
  15 static void dsa_master_get_ethtool_stats(struct net_device *dev,
  16                                          struct ethtool_stats *stats,
  17                                          uint64_t *data)
  18 {
  19         struct dsa_port *cpu_dp = dev->dsa_ptr;
  20         const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
  21         struct dsa_switch *ds = cpu_dp->ds;
  22         int port = cpu_dp->index;
  23         int count = 0;
  24
  25         if (ops && ops->get_sset_count && ops->get_ethtool_stats) {
  26                 count = ops->get_sset_count(dev, ETH_SS_STATS);
  27                 ops->get_ethtool_stats(dev, stats, data);
  28         }
  29
  30         if (ds->ops->get_ethtool_stats)
  31                 ds->ops->get_ethtool_stats(ds, port, data + count);
  32 }
  33
  34 static int dsa_master_get_sset_count(struct net_device *dev, int sset)
  35 {
  36         struct dsa_port *cpu_dp = dev->dsa_ptr;
  37         const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
  38         struct dsa_switch *ds = cpu_dp->ds;
  39         int count = 0;
  40
  41         if (ops && ops->get_sset_count)
  42                 count += ops->get_sset_count(dev, sset);
  43
  44         if (sset == ETH_SS_STATS && ds->ops->get_sset_count)
  45                 count += ds->ops->get_sset_count(ds);
  46
  47         return count;
  48 }
  49
  50 static void dsa_master_get_strings(struct net_device *dev, uint32_t stringset,
  51                                    uint8_t *data)
  52 {
  53         struct dsa_port *cpu_dp = dev->dsa_ptr;
  54         const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
  55         struct dsa_switch *ds = cpu_dp->ds;
  56         int port = cpu_dp->index;
  57         int len = ETH_GSTRING_LEN;
  58         int mcount = 0, count;
  59         unsigned int i;
  60         uint8_t pfx[4];
  61         uint8_t *ndata;
  62
  63         snprintf(pfx, sizeof(pfx), "p%.2d", port);
  64         /* We do not want to be NULL-terminated, since this is a prefix */
  65         pfx[sizeof(pfx) - 1] = '_';
  66
  67         if (ops && ops->get_sset_count && ops->get_strings) {
  68                 mcount = ops->get_sset_count(dev, ETH_SS_STATS);
  69                 ops->get_strings(dev, stringset, data);
  70         }
  71
  72         if (stringset == ETH_SS_STATS && ds->ops->get_strings) {
  73                 ndata = data + mcount * len;
  74                 /* This function copies ETH_GSTRINGS_LEN bytes, we will mangle
  75                  * the output after to prepend our CPU port prefix we
  76                  * constructed earlier
  77                  */
  78                 ds->ops->get_strings(ds, port, ndata);
  79                 count = ds->ops->get_sset_count(ds);
  80                 for (i = 0; i < count; i++) {
  81                         memmove(ndata + (i * len + sizeof(pfx)),
  82                                 ndata + i * len, len - sizeof(pfx));
  83                         memcpy(ndata + i * len, pfx, sizeof(pfx));
  84                 }
  85         }
  86 }
  87
  88 static int dsa_master_ethtool_setup(struct net_device *dev)
  89 {
  90         struct dsa_port *cpu_dp = dev->dsa_ptr;
  91         struct dsa_switch *ds = cpu_dp->ds;
  92         struct ethtool_ops *ops;
  93
  94         ops = devm_kzalloc(ds->dev, sizeof(*ops), GFP_KERNEL);
  95         if (!ops)
  96                 return -ENOMEM;
  97
  98         cpu_dp->orig_ethtool_ops = dev->ethtool_ops;
  99         if (cpu_dp->orig_ethtool_ops)
 100                 memcpy(ops, cpu_dp->orig_ethtool_ops, sizeof(*ops));
 101
 102         ops->get_sset_count = dsa_master_get_sset_count;
 103         ops->get_ethtool_stats = dsa_master_get_ethtool_stats;
 104         ops->get_strings = dsa_master_get_strings;
 105
 106         dev->ethtool_ops = ops;
 107
 108         return 0;
 109 }
 110
 111 static void dsa_master_ethtool_teardown(struct net_device *dev)
 112 {
 113         struct dsa_port *cpu_dp = dev->dsa_ptr;
 114
 115         dev->ethtool_ops = cpu_dp->orig_ethtool_ops;
 116         cpu_dp->orig_ethtool_ops = NULL;
 117 }
 118
 119 int dsa_master_setup(struct net_device *dev, struct dsa_port *cpu_dp)
 120 {
 121         /* If we use a tagging format that doesn't have an ethertype
 122          * field, make sure that all packets from this point on get
 123          * sent to the tag format's receive function.
 124          */
 125         wmb();
 126
 127         dev->dsa_ptr = cpu_dp;
 128
 129         return dsa_master_ethtool_setup(dev);
 130 }
 131
 132 void dsa_master_teardown(struct net_device *dev)
 133 {
 134         dsa_master_ethtool_teardown(dev);
 135
 136         dev->dsa_ptr = NULL;
 137
 138         /* If we used a tagging format that doesn't have an ethertype
 139          * field, make sure that all packets from this point get sent
 140          * without the tag and go through the regular receive path.
 141          */
 142         wmb();
 143 }