net/ncsi/ncsi-aen.c

   1 /*
   2  * Copyright Gavin Shan, IBM Corporation 2016.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  */
   9
  10 #include <linux/module.h>
  11 #include <linux/kernel.h>
  12 #include <linux/init.h>
  13 #include <linux/netdevice.h>
  14 #include <linux/skbuff.h>
  15
  16 #include <net/ncsi.h>
  17 #include <net/net_namespace.h>
  18 #include <net/sock.h>
  19
  20 #include "internal.h"
  21 #include "ncsi-pkt.h"
  22
  23 static int ncsi_validate_aen_pkt(struct ncsi_aen_pkt_hdr *h,
  24                                  const unsigned short payload)
  25 {
  26         u32 checksum;
  27         __be32 *pchecksum;
  28
  29         if (h->common.revision != NCSI_PKT_REVISION)
  30                 return -EINVAL;
  31         if (ntohs(h->common.length) != payload)
  32                 return -EINVAL;
  33
  34         /* Validate checksum, which might be zeroes if the
  35          * sender doesn't support checksum according to NCSI
  36          * specification.
  37          */
  38         pchecksum = (__be32 *)((void *)(h + 1) + payload - 4);
  39         if (ntohl(*pchecksum) == 0)
  40                 return 0;
  41
  42         checksum = ncsi_calculate_checksum((unsigned char *)h,
  43                                            sizeof(*h) + payload - 4);
  44         if (*pchecksum != htonl(checksum))
  45                 return -EINVAL;
  46
  47         return 0;
  48 }
  49
  50 static int ncsi_aen_handler_lsc(struct ncsi_dev_priv *ndp,
  51                                 struct ncsi_aen_pkt_hdr *h)
  52 {
  53         struct ncsi_aen_lsc_pkt *lsc;
  54         struct ncsi_channel *nc;
  55         struct ncsi_channel_mode *ncm;
  56         bool chained;
  57         int state;
  58         unsigned long old_data, data;
  59         unsigned long flags;
  60
  61         /* Find the NCSI channel */
  62         ncsi_find_package_and_channel(ndp, h->common.channel, NULL, &nc);
  63         if (!nc)
  64                 return -ENODEV;
  65
  66         /* Update the link status */
  67         lsc = (struct ncsi_aen_lsc_pkt *)h;
  68
  69         spin_lock_irqsave(&nc->lock, flags);
  70         ncm = &nc->modes[NCSI_MODE_LINK];
  71         old_data = ncm->data[2];
  72         data = ntohl(lsc->status);
  73         ncm->data[2] = data;
  74         ncm->data[4] = ntohl(lsc->oem_status);
  75
  76         chained = !list_empty(&nc->link);
  77         state = nc->state;
  78         spin_unlock_irqrestore(&nc->lock, flags);
  79
  80         if (!((old_data ^ data) & 0x1) || chained)
  81                 return 0;
  82         if (!(state == NCSI_CHANNEL_INACTIVE && (data & 0x1)) &&
  83             !(state == NCSI_CHANNEL_ACTIVE && !(data & 0x1)))
  84                 return 0;
  85
  86         if (!(ndp->flags & NCSI_DEV_HWA) &&
  87             state == NCSI_CHANNEL_ACTIVE)
  88                 ndp->flags |= NCSI_DEV_RESHUFFLE;
  89
  90         ncsi_stop_channel_monitor(nc);
  91         spin_lock_irqsave(&ndp->lock, flags);
  92         list_add_tail_rcu(&nc->link, &ndp->channel_queue);
  93         spin_unlock_irqrestore(&ndp->lock, flags);
  94
  95         return ncsi_process_next_channel(ndp);
  96 }
  97
  98 static int ncsi_aen_handler_cr(struct ncsi_dev_priv *ndp,
  99                                struct ncsi_aen_pkt_hdr *h)
 100 {
 101         struct ncsi_channel *nc;
 102         unsigned long flags;
 103
 104         /* Find the NCSI channel */
 105         ncsi_find_package_and_channel(ndp, h->common.channel, NULL, &nc);
 106         if (!nc)
 107                 return -ENODEV;
 108
 109         spin_lock_irqsave(&nc->lock, flags);
 110         if (!list_empty(&nc->link) ||
 111             nc->state != NCSI_CHANNEL_ACTIVE) {
 112                 spin_unlock_irqrestore(&nc->lock, flags);
 113                 return 0;
 114         }
 115         spin_unlock_irqrestore(&nc->lock, flags);
 116
 117         ncsi_stop_channel_monitor(nc);
 118         spin_lock_irqsave(&nc->lock, flags);
 119         nc->state = NCSI_CHANNEL_INVISIBLE;
 120         spin_unlock_irqrestore(&nc->lock, flags);
 121
 122         spin_lock_irqsave(&ndp->lock, flags);
 123         nc->state = NCSI_CHANNEL_INACTIVE;
 124         list_add_tail_rcu(&nc->link, &ndp->channel_queue);
 125         spin_unlock_irqrestore(&ndp->lock, flags);
 126
 127         return ncsi_process_next_channel(ndp);
 128 }
 129
 130 static int ncsi_aen_handler_hncdsc(struct ncsi_dev_priv *ndp,
 131                                    struct ncsi_aen_pkt_hdr *h)
 132 {
 133         struct ncsi_channel *nc;
 134         struct ncsi_channel_mode *ncm;
 135         struct ncsi_aen_hncdsc_pkt *hncdsc;
 136         unsigned long flags;
 137
 138         /* Find the NCSI channel */
 139         ncsi_find_package_and_channel(ndp, h->common.channel, NULL, &nc);
 140         if (!nc)
 141                 return -ENODEV;
 142
 143         /* If the channel is active one, we need reconfigure it */
 144         ncm = &nc->modes[NCSI_MODE_LINK];
 145         hncdsc = (struct ncsi_aen_hncdsc_pkt *)h;
 146         ncm->data[3] = ntohl(hncdsc->status);
 147         if (!list_empty(&nc->link) ||
 148             nc->state != NCSI_CHANNEL_ACTIVE ||
 149             (ncm->data[3] & 0x1))
 150                 return 0;
 151
 152         if (ndp->flags & NCSI_DEV_HWA)
 153                 ndp->flags |= NCSI_DEV_RESHUFFLE;
 154
 155         /* If this channel is the active one and the link doesn't
 156          * work, we have to choose another channel to be active one.
 157          * The logic here is exactly similar to what we do when link
 158          * is down on the active channel.
 159          */
 160         ncsi_stop_channel_monitor(nc);
 161         spin_lock_irqsave(&ndp->lock, flags);
 162         list_add_tail_rcu(&nc->link, &ndp->channel_queue);
 163         spin_unlock_irqrestore(&ndp->lock, flags);
 164
 165         ncsi_process_next_channel(ndp);
 166
 167         return 0;
 168 }
 169
 170 static struct ncsi_aen_handler {
 171         unsigned char type;
 172         int           payload;
 173         int           (*handler)(struct ncsi_dev_priv *ndp,
 174                                  struct ncsi_aen_pkt_hdr *h);
 175 } ncsi_aen_handlers[] = {
 176         { NCSI_PKT_AEN_LSC,    12, ncsi_aen_handler_lsc    },
 177         { NCSI_PKT_AEN_CR,      4, ncsi_aen_handler_cr     },
 178         { NCSI_PKT_AEN_HNCDSC,  4, ncsi_aen_handler_hncdsc }
 179 };
 180
 181 int ncsi_aen_handler(struct ncsi_dev_priv *ndp, struct sk_buff *skb)
 182 {
 183         struct ncsi_aen_pkt_hdr *h;
 184         struct ncsi_aen_handler *nah = NULL;
 185         int i, ret;
 186
 187         /* Find the handler */
 188         h = (struct ncsi_aen_pkt_hdr *)skb_network_header(skb);
 189         for (i = 0; i < ARRAY_SIZE(ncsi_aen_handlers); i++) {
 190                 if (ncsi_aen_handlers[i].type == h->type) {
 191                         nah = &ncsi_aen_handlers[i];
 192                         break;
 193                 }
 194         }
 195
 196         if (!nah) {
 197                 netdev_warn(ndp->ndev.dev, "Invalid AEN (0x%x) received\n",
 198                             h->type);
 199                 return -ENOENT;
 200         }
 201
 202         ret = ncsi_validate_aen_pkt(h, nah->payload);
 203         if (ret)
 204                 goto out;
 205
 206         ret = nah->handler(ndp, h);
 207 out:
 208         consume_skb(skb);
 209         return ret;
 210 }