iwlwifi: better station table maintenance

This patch makes the station table maintenance safer. Two flags are
maintained:

1) if station is present in driver
2) if station is present in uCode

This will allow us in the future to deal with more stations than the
firmware allows.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 95 insertions, 51 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-sta.c b/drivers/net/wireless/iwlwifi/iwl-sta.c
index f874e7d7b225..c81ab5f9830f 100644
--- a/drivers/net/wireless/iwlwifi/iwl-sta.c
+++ b/drivers/net/wireless/iwlwifi/iwl-sta.c
@@ -36,8 +36,8 @@
 #include "iwl-helpers.h"
 
 
-#define IWL_STA_DRIVER_ACTIVE           0x1     /* ucode entry is active */
-#define IWL_STA_UCODE_ACTIVE            0x2     /* ucode entry is active */
+#define IWL_STA_DRIVER_ACTIVE BIT(0) /* driver entry is active */
+#define IWL_STA_UCODE_ACTIVE  BIT(1) /* ucode entry is active */
 
 u8 iwl_find_station(struct iwl_priv *priv, const u8 *addr)
 {
@@ -83,10 +83,28 @@ int iwl_get_ra_sta_id(struct iwl_priv *priv, struct ieee80211_hdr *hdr)
 }
 EXPORT_SYMBOL(iwl_get_ra_sta_id);
 
+static void iwl_sta_ucode_activate(struct iwl_priv *priv, u8 sta_id)
+{
+        unsigned long flags;
+        DECLARE_MAC_BUF(mac);
+
+        spin_lock_irqsave(&priv->sta_lock, flags);
+
+        if (!(priv->stations[sta_id].used & IWL_STA_DRIVER_ACTIVE))
+                IWL_ERROR("ACTIVATE a non DRIVER active station %d\n", sta_id);
+
+        priv->stations[sta_id].used |= IWL_STA_UCODE_ACTIVE;
+        IWL_DEBUG_ASSOC("Added STA to Ucode: %s\n",
+                        print_mac(mac, priv->stations[sta_id].sta.sta.addr));
+
+        spin_unlock_irqrestore(&priv->sta_lock, flags);
+}
+
 static int iwl_add_sta_callback(struct iwl_priv *priv,
                                    struct iwl_cmd *cmd, struct sk_buff *skb)
 {
         struct iwl_rx_packet *res = NULL;
+        u8 sta_id = cmd->cmd.addsta.sta.sta_id;
 
         if (!skb) {
                 IWL_ERROR("Error: Response NULL in REPLY_ADD_STA.\n");
@@ -102,8 +120,8 @@ static int iwl_add_sta_callback(struct iwl_priv *priv,
 
         switch (res->u.add_sta.status) {
         case ADD_STA_SUCCESS_MSK:
-                /* FIXME: implement iwl_sta_ucode_activate(priv, addr); */
-                /* fail through */
+                iwl_sta_ucode_activate(priv, sta_id);
+                 /* fall through */
         default:
                 IWL_DEBUG_HC("Received REPLY_ADD_STA:(0x%08X)\n",
                              res->u.add_sta.status);
@@ -147,6 +165,7 @@ int iwl_send_add_sta(struct iwl_priv *priv,
         if (ret == 0) {
                 switch (res->u.add_sta.status) {
                 case ADD_STA_SUCCESS_MSK:
+                        iwl_sta_ucode_activate(priv, sta->sta.sta_id);
                         IWL_DEBUG_INFO("REPLY_ADD_STA PASSED\n");
                         break;
                 default:
@@ -215,88 +234,92 @@ u8 iwl_add_station_flags(struct iwl_priv *priv, const u8 *addr, int is_ap,
                          u8 flags, struct ieee80211_ht_info *ht_info)
 {
         int i;
-        int index = IWL_INVALID_STATION;
+        int sta_id = IWL_INVALID_STATION;
         struct iwl_station_entry *station;
         unsigned long flags_spin;
         DECLARE_MAC_BUF(mac);
 
         spin_lock_irqsave(&priv->sta_lock, flags_spin);
         if (is_ap)
-                index = IWL_AP_ID;
+                sta_id = IWL_AP_ID;
         else if (is_broadcast_ether_addr(addr))
-                index = priv->hw_params.bcast_sta_id;
+                sta_id = priv->hw_params.bcast_sta_id;
         else
                 for (i = IWL_STA_ID; i < priv->hw_params.max_stations; i++) {
                         if (!compare_ether_addr(priv->stations[i].sta.sta.addr,
                                                 addr)) {
-                                index = i;
+                                sta_id = i;
                                 break;
                         }
 
                         if (!priv->stations[i].used &&
-                            index == IWL_INVALID_STATION)
-                                index = i;
+                            sta_id == IWL_INVALID_STATION)
+                                sta_id = i;
                 }
 
-
         /* These two conditions have the same outcome, but keep them separate
-          since they have different meanings */
-        if (unlikely(index == IWL_INVALID_STATION)) {
+           since they have different meanings */
+        if (unlikely(sta_id == IWL_INVALID_STATION)) {
                 spin_unlock_irqrestore(&priv->sta_lock, flags_spin);
-                return index;
+                return sta_id;
         }
 
-        if (priv->stations[index].used &&
-            !compare_ether_addr(priv->stations[index].sta.sta.addr, addr)) {
+        if (priv->stations[sta_id].used &&
+            !compare_ether_addr(priv->stations[sta_id].sta.sta.addr, addr)) {
                 spin_unlock_irqrestore(&priv->sta_lock, flags_spin);
-                return index;
+                return sta_id;
         }
 
 
-        IWL_DEBUG_ASSOC("Add STA ID %d: %s\n", index, print_mac(mac, addr));
-        station = &priv->stations[index];
-        station->used = 1;
+        station = &priv->stations[sta_id];
+        station->used = IWL_STA_DRIVER_ACTIVE;
+        IWL_DEBUG_ASSOC("Add STA to driver ID %d: %s\n",
+                        sta_id, print_mac(mac, addr));
         priv->num_stations++;
 
         /* Set up the REPLY_ADD_STA command to send to device */
         memset(&station->sta, 0, sizeof(struct iwl_addsta_cmd));
         memcpy(station->sta.sta.addr, addr, ETH_ALEN);
         station->sta.mode = 0;
-        station->sta.sta.sta_id = index;
+        station->sta.sta.sta_id = sta_id;
         station->sta.station_flags = 0;
 
         /* BCAST station and IBSS stations do not work in HT mode */
-        if (index != priv->hw_params.bcast_sta_id &&
+        if (sta_id != priv->hw_params.bcast_sta_id &&
             priv->iw_mode != IEEE80211_IF_TYPE_IBSS)
-                iwl_set_ht_add_station(priv, index, ht_info);
+                iwl_set_ht_add_station(priv, sta_id, ht_info);
 
         spin_unlock_irqrestore(&priv->sta_lock, flags_spin);
 
         /* Add station to device's station table */
         iwl_send_add_sta(priv, &station->sta, flags);
-        return index;
+        return sta_id;
 
 }
 EXPORT_SYMBOL(iwl_add_station_flags);
 
-static int iwl_sta_ucode_deactivate(struct iwl_priv *priv, const char *addr)
+static void iwl_sta_ucode_deactivate(struct iwl_priv *priv, const char *addr)
 {
         unsigned long flags;
-        u8 sta_id;
         DECLARE_MAC_BUF(mac);
 
-        sta_id = iwl_find_station(priv, addr);
-        if (sta_id != IWL_INVALID_STATION) {
-                IWL_DEBUG_ASSOC("Removed STA from Ucode: %s\n",
-                                print_mac(mac, addr));
-                spin_lock_irqsave(&priv->sta_lock, flags);
-                priv->stations[sta_id].used &= ~IWL_STA_UCODE_ACTIVE;
-                memset(&priv->stations[sta_id], 0,
-                        sizeof(struct iwl_station_entry));
-                spin_unlock_irqrestore(&priv->sta_lock, flags);
-                return 0;
-        }
-        return -EINVAL;
+        u8 sta_id = iwl_find_station(priv, addr);
+
+        BUG_ON(sta_id == IWL_INVALID_STATION);
+
+        IWL_DEBUG_ASSOC("Removed STA from Ucode: %s\n",
+                        print_mac(mac, addr));
+
+        spin_lock_irqsave(&priv->sta_lock, flags);
+
+        /* Ucode must be active and driver must be non active */
+        if (priv->stations[sta_id].used != IWL_STA_UCODE_ACTIVE)
+                IWL_ERROR("removed non active STA %d\n", sta_id);
+
+        priv->stations[sta_id].used &= ~IWL_STA_UCODE_ACTIVE;
+
+        memset(&priv->stations[sta_id], 0, sizeof(struct iwl_station_entry));
+        spin_unlock_irqrestore(&priv->sta_lock, flags);
 }
 
 static int iwl_remove_sta_callback(struct iwl_priv *priv,
@@ -322,6 +345,7 @@ static int iwl_remove_sta_callback(struct iwl_priv *priv,
                 iwl_sta_ucode_deactivate(priv, addr);
                 break;
         default:
+                IWL_ERROR("REPLY_REMOVE_STA failed\n");
                 break;
         }
 
@@ -386,44 +410,63 @@ static int iwl_send_remove_station(struct iwl_priv *priv, const u8 *addr,
 /**
  * iwl_remove_station - Remove driver's knowledge of station.
  */
-u8 iwl_remove_station(struct iwl_priv *priv, const u8 *addr, int is_ap)
+int iwl_remove_station(struct iwl_priv *priv, const u8 *addr, int is_ap)
 {
-        int index = IWL_INVALID_STATION;
-        int i;
+        int sta_id = IWL_INVALID_STATION;
+        int i, ret = -EINVAL;
         unsigned long flags;
+        DECLARE_MAC_BUF(mac);
 
         spin_lock_irqsave(&priv->sta_lock, flags);
 
         if (is_ap)
-                index = IWL_AP_ID;
+                sta_id = IWL_AP_ID;
         else if (is_broadcast_ether_addr(addr))
-                index = priv->hw_params.bcast_sta_id;
+                sta_id = priv->hw_params.bcast_sta_id;
         else
                 for (i = IWL_STA_ID; i < priv->hw_params.max_stations; i++)
                         if (priv->stations[i].used &&
                             !compare_ether_addr(priv->stations[i].sta.sta.addr,
                                                 addr)) {
-                                index = i;
+                                sta_id = i;
                                 break;
                         }
 
-        if (unlikely(index == IWL_INVALID_STATION))
+        if (unlikely(sta_id == IWL_INVALID_STATION))
                 goto out;
 
-        if (priv->stations[index].used) {
-                priv->stations[index].used = 0;
-                priv->num_stations--;
+        IWL_DEBUG_ASSOC("Removing STA from driver:%d  %s\n",
+                sta_id, print_mac(mac, addr));
+
+        if (!(priv->stations[sta_id].used & IWL_STA_DRIVER_ACTIVE)) {
+                IWL_ERROR("Removing %s but non DRIVER active\n",
+                                print_mac(mac, addr));
+                goto out;
+        }
+
+        if (!(priv->stations[sta_id].used & IWL_STA_UCODE_ACTIVE)) {
+                IWL_ERROR("Removing %s but non UCODE active\n",
+                                print_mac(mac, addr));
+                goto out;
         }
 
+
+        priv->stations[sta_id].used &= ~IWL_STA_DRIVER_ACTIVE;
+
+        priv->num_stations--;
+
         BUG_ON(priv->num_stations < 0);
+
         spin_unlock_irqrestore(&priv->sta_lock, flags);
-        iwl_send_remove_station(priv, addr, CMD_ASYNC);
-        return index;
+
+        ret = iwl_send_remove_station(priv, addr, CMD_ASYNC);
+        return ret;
 out:
         spin_unlock_irqrestore(&priv->sta_lock, flags);
-        return 0;
+        return ret;
 }
 EXPORT_SYMBOL(iwl_remove_station);
+
 static int iwl_get_free_ucode_key_index(struct iwl_priv *priv)
 {
         int i;
@@ -845,6 +888,7 @@ static void iwl_sta_init_lq(struct iwl_priv *priv, const u8 *addr, int is_ap)
         iwl_send_cmd_pdu_async(priv, REPLY_TX_LINK_QUALITY_CMD,
                                sizeof(link_cmd), &link_cmd, NULL);
 }
+
 /**
  * iwl_rxon_add_station - add station into station table.
  *