drivers/net/wireless/libertas/tx.c

   1 /*
   2  * This file contains the handling of TX in wlan driver.
   3  */
   4 #include <linux/hardirq.h>
   5 #include <linux/netdevice.h>
   6 #include <linux/etherdevice.h>
   7 #include <linux/sched.h>
   8 #include <net/cfg80211.h>
   9
  10 #include "host.h"
  11 #include "radiotap.h"
  12 #include "decl.h"
  13 #include "defs.h"
  14 #include "dev.h"
  15 #include "mesh.h"
  16
  17 /**
  18  * convert_radiotap_rate_to_mv - converts Tx/Rx rates from IEEE80211_RADIOTAP_RATE
  19  * units (500 Kb/s) into Marvell WLAN format (see Table 8 in Section 3.2.1)
  20  *
  21  * @rate:       Input rate
  22  * returns:     Output Rate (0 if invalid)
  23  */
  24 static u32 convert_radiotap_rate_to_mv(u8 rate)
  25 {
  26         switch (rate) {
  27         case 2:         /*   1 Mbps */
  28                 return 0 | (1 << 4);
  29         case 4:         /*   2 Mbps */
  30                 return 1 | (1 << 4);
  31         case 11:                /* 5.5 Mbps */
  32                 return 2 | (1 << 4);
  33         case 22:                /*  11 Mbps */
  34                 return 3 | (1 << 4);
  35         case 12:                /*   6 Mbps */
  36                 return 4 | (1 << 4);
  37         case 18:                /*   9 Mbps */
  38                 return 5 | (1 << 4);
  39         case 24:                /*  12 Mbps */
  40                 return 6 | (1 << 4);
  41         case 36:                /*  18 Mbps */
  42                 return 7 | (1 << 4);
  43         case 48:                /*  24 Mbps */
  44                 return 8 | (1 << 4);
  45         case 72:                /*  36 Mbps */
  46                 return 9 | (1 << 4);
  47         case 96:                /*  48 Mbps */
  48                 return 10 | (1 << 4);
  49         case 108:               /*  54 Mbps */
  50                 return 11 | (1 << 4);
  51         }
  52         return 0;
  53 }
  54
  55 /**
  56  * lbs_hard_start_xmit - checks the conditions and sends packet to IF
  57  * layer if everything is ok
  58  *
  59  * @skb:        A pointer to skb which includes TX packet
  60  * @dev:        A pointer to the &struct net_device
  61  * returns:     0 or -1
  62  */
  63 netdev_tx_t lbs_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
  64 {
  65         unsigned long flags;
  66         struct lbs_private *priv = dev->ml_priv;
  67         struct txpd *txpd;
  68         char *p802x_hdr;
  69         uint16_t pkt_len;
  70         netdev_tx_t ret = NETDEV_TX_OK;
  71
  72         lbs_deb_enter(LBS_DEB_TX);
  73
  74         /* We need to protect against the queues being restarted before
  75            we get round to stopping them */
  76         spin_lock_irqsave(&priv->driver_lock, flags);
  77
  78         if (priv->surpriseremoved)
  79                 goto free;
  80
  81         if (!skb->len || (skb->len > MRVDRV_ETH_TX_PACKET_BUFFER_SIZE)) {
  82                 lbs_deb_tx("tx err: skb length %d 0 or > %zd\n",
  83                        skb->len, MRVDRV_ETH_TX_PACKET_BUFFER_SIZE);
  84                 /* We'll never manage to send this one; drop it and return 'OK' */
  85
  86                 dev->stats.tx_dropped++;
  87                 dev->stats.tx_errors++;
  88                 goto free;
  89         }
  90
  91
  92         netif_stop_queue(priv->dev);
  93         if (priv->mesh_dev)
  94                 netif_stop_queue(priv->mesh_dev);
  95
  96         if (priv->tx_pending_len) {
  97                 /* This can happen if packets come in on the mesh and eth
  98                    device simultaneously -- there's no mutual exclusion on
  99                    hard_start_xmit() calls between devices. */
 100                 lbs_deb_tx("Packet on %s while busy\n", dev->name);
 101                 ret = NETDEV_TX_BUSY;
 102                 goto unlock;
 103         }
 104
 105         priv->tx_pending_len = -1;
 106         spin_unlock_irqrestore(&priv->driver_lock, flags);
 107
 108         lbs_deb_hex(LBS_DEB_TX, "TX Data", skb->data, min_t(unsigned int, skb->len, 100));
 109
 110         txpd = (void *)priv->tx_pending_buf;
 111         memset(txpd, 0, sizeof(struct txpd));
 112
 113         p802x_hdr = skb->data;
 114         pkt_len = skb->len;
 115
 116         if (priv->wdev->iftype == NL80211_IFTYPE_MONITOR) {
 117                 struct tx_radiotap_hdr *rtap_hdr = (void *)skb->data;
 118
 119                 /* set txpd fields from the radiotap header */
 120                 txpd->tx_control = cpu_to_le32(convert_radiotap_rate_to_mv(rtap_hdr->rate));
 121
 122                 /* skip the radiotap header */
 123                 p802x_hdr += sizeof(*rtap_hdr);
 124                 pkt_len -= sizeof(*rtap_hdr);
 125
 126                 /* copy destination address from 802.11 header */
 127                 memcpy(txpd->tx_dest_addr_high, p802x_hdr + 4, ETH_ALEN);
 128         } else {
 129                 /* copy destination address from 802.3 header */
 130                 memcpy(txpd->tx_dest_addr_high, p802x_hdr, ETH_ALEN);
 131         }
 132
 133         txpd->tx_packet_length = cpu_to_le16(pkt_len);
 134         txpd->tx_packet_location = cpu_to_le32(sizeof(struct txpd));
 135
 136         lbs_mesh_set_txpd(priv, dev, txpd);
 137
 138         lbs_deb_hex(LBS_DEB_TX, "txpd", (u8 *) &txpd, sizeof(struct txpd));
 139
 140         lbs_deb_hex(LBS_DEB_TX, "Tx Data", (u8 *) p802x_hdr, le16_to_cpu(txpd->tx_packet_length));
 141
 142         memcpy(&txpd[1], p802x_hdr, le16_to_cpu(txpd->tx_packet_length));
 143
 144         spin_lock_irqsave(&priv->driver_lock, flags);
 145         priv->tx_pending_len = pkt_len + sizeof(struct txpd);
 146
 147         lbs_deb_tx("%s lined up packet\n", __func__);
 148
 149         dev->stats.tx_packets++;
 150         dev->stats.tx_bytes += skb->len;
 151
 152         if (priv->wdev->iftype == NL80211_IFTYPE_MONITOR) {
 153                 /* Keep the skb to echo it back once Tx feedback is
 154                    received from FW */
 155                 skb_orphan(skb);
 156
 157                 /* Keep the skb around for when we get feedback */
 158                 priv->currenttxskb = skb;
 159         } else {
 160  free:
 161                 dev_kfree_skb_any(skb);
 162         }
 163
 164  unlock:
 165         spin_unlock_irqrestore(&priv->driver_lock, flags);
 166         wake_up(&priv->waitq);
 167
 168         lbs_deb_leave_args(LBS_DEB_TX, "ret %d", ret);
 169         return ret;
 170 }
 171
 172 /**
 173  * lbs_send_tx_feedback - sends to the host the last transmitted packet,
 174  * filling the radiotap headers with transmission information.
 175  *
 176  * @priv:       A pointer to &struct lbs_private structure
 177  * @try_count:  A 32-bit value containing transmission retry status.
 178  *
 179  * returns:     void
 180  */
 181 void lbs_send_tx_feedback(struct lbs_private *priv, u32 try_count)
 182 {
 183         struct tx_radiotap_hdr *radiotap_hdr;
 184
 185         if (priv->wdev->iftype != NL80211_IFTYPE_MONITOR ||
 186             priv->currenttxskb == NULL)
 187                 return;
 188
 189         radiotap_hdr = (struct tx_radiotap_hdr *)priv->currenttxskb->data;
 190
 191         radiotap_hdr->data_retries = try_count ?
 192                 (1 + priv->txretrycount - try_count) : 0;
 193
 194         priv->currenttxskb->protocol = eth_type_trans(priv->currenttxskb,
 195                                                       priv->dev);
 196         netif_rx(priv->currenttxskb);
 197
 198         priv->currenttxskb = NULL;
 199
 200         if (priv->connect_status == LBS_CONNECTED)
 201                 netif_wake_queue(priv->dev);
 202
 203         if (priv->mesh_dev && netif_running(priv->mesh_dev))
 204                 netif_wake_queue(priv->mesh_dev);
 205 }
 206 EXPORT_SYMBOL_GPL(lbs_send_tx_feedback);