p54: utilize cryptographic accelerator

This patch allows p54 to utilize its WEP, TKIP and CCMP accelerator.

Tested-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Christian Lamparter <chunkeey@web.de>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

2 files changed, 168 insertions, 13 deletions

diff --git a/drivers/net/wireless/p54/p54.h b/drivers/net/wireless/p54/p54.h
index 491ab96c7b6..ebe1ea1f565 100644
--- a/drivers/net/wireless/p54/p54.h
+++ b/drivers/net/wireless/p54/p54.h
@@ -115,6 +115,8 @@ struct p54_common {
         int noise;
         void *eeprom;
         struct completion eeprom_comp;
+        u8 privacy_caps;
+        u8 rx_keycache_size;
 };
 
 int p54_rx(struct ieee80211_hw *dev, struct sk_buff *skb);
diff --git a/drivers/net/wireless/p54/p54common.c b/drivers/net/wireless/p54/p54common.c
index de92b58d450..6f7e82b56cb 100644
--- a/drivers/net/wireless/p54/p54common.c
+++ b/drivers/net/wireless/p54/p54common.c
@@ -25,6 +25,9 @@
 #include "p54.h"
 #include "p54common.h"
 
+static int modparam_nohwcrypt;
+module_param_named(nohwcrypt, modparam_nohwcrypt, bool, S_IRUGO);
+MODULE_PARM_DESC(nohwcrypt, "Disable hardware encryption.");
 MODULE_AUTHOR("Michael Wu <flamingice@sourmilk.net>");
 MODULE_DESCRIPTION("Softmac Prism54 common code");
 MODULE_LICENSE("GPL");
@@ -185,6 +188,8 @@ int p54_parse_firmware(struct ieee80211_hw *dev, const struct firmware *fw)
                         priv->rx_end = le32_to_cpu(desc->rx_end) - 0x3500;
                         priv->headroom = desc->headroom;
                         priv->tailroom = desc->tailroom;
+                        priv->privacy_caps = desc->privacy_caps;
+                        priv->rx_keycache_size = desc->rx_keycache_size;
                         if (le32_to_cpu(bootrec->len) == 11)
                                 priv->rx_mtu = le16_to_cpu(desc->rx_mtu);
                         else
@@ -228,6 +233,16 @@ int p54_parse_firmware(struct ieee80211_hw *dev, const struct firmware *fw)
                 dev->queues = 4;
         }
 
+        if (!modparam_nohwcrypt)
+                printk(KERN_INFO "%s: cryptographic accelerator "
+                                 "WEP:%s, TKIP:%s, CCMP:%s\n",
+                        wiphy_name(dev->wiphy),
+                        (priv->privacy_caps & BR_DESC_PRIV_CAP_WEP) ? "YES" :
+                        "no", (priv->privacy_caps & (BR_DESC_PRIV_CAP_TKIP |
+                         BR_DESC_PRIV_CAP_MICHAEL)) ? "YES" : "no",
+                        (priv->privacy_caps & BR_DESC_PRIV_CAP_AESCCMP) ?
+                        "YES" : "no");
+
         return 0;
 }
 EXPORT_SYMBOL_GPL(p54_parse_firmware);
@@ -526,6 +541,12 @@ static int p54_rx_data(struct ieee80211_hw *dev, struct sk_buff *skb)
                         return 0;
         }
 
+        if (hdr->decrypt_status == P54_DECRYPT_OK)
+                rx_status.flag |= RX_FLAG_DECRYPTED;
+        if ((hdr->decrypt_status == P54_DECRYPT_FAIL_MICHAEL) ||
+            (hdr->decrypt_status == P54_DECRYPT_FAIL_TKIP))
+                rx_status.flag |= RX_FLAG_MMIC_ERROR;
+
         rx_status.signal = p54_rssi_to_dbm(dev, hdr->rssi);
         rx_status.noise = priv->noise;
         /* XX correct? */
@@ -1107,6 +1128,20 @@ static int p54_tx_fill(struct ieee80211_hw *dev, struct sk_buff *skb,
         return ret;
 }
 
+static u8 p54_convert_algo(enum ieee80211_key_alg alg)
+{
+        switch (alg) {
+        case ALG_WEP:
+                return P54_CRYPTO_WEP;
+        case ALG_TKIP:
+                return P54_CRYPTO_TKIPMICHAEL;
+        case ALG_CCMP:
+                return P54_CRYPTO_AESCCMP;
+        default:
+                return 0;
+        }
+}
+
 static int p54_tx(struct ieee80211_hw *dev, struct sk_buff *skb)
 {
         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
@@ -1117,7 +1152,7 @@ static int p54_tx(struct ieee80211_hw *dev, struct sk_buff *skb)
         size_t padding, len, tim_len = 0;
         int i, j, ridx, ret;
         u16 hdr_flags = 0, aid = 0;
-        u8 rate, queue;
+        u8 rate, queue, crypt_offset = 0;
         u8 cts_rate = 0x20;
         u8 rc_flags;
         u8 calculated_tries[4];
@@ -1137,12 +1172,25 @@ static int p54_tx(struct ieee80211_hw *dev, struct sk_buff *skb)
         padding = (unsigned long)(skb->data - (sizeof(*hdr) + sizeof(*txhdr))) & 3;
         len = skb->len;
 
+        if (info->control.hw_key) {
+                crypt_offset = ieee80211_get_hdrlen_from_skb(skb);
+                if (info->control.hw_key->alg == ALG_TKIP) {
+                        u8 *iv = (u8 *)(skb->data + crypt_offset);
+                        /*
+                         * The firmware excepts that the IV has to have
+                         * this special format
+                         */
+                        iv[1] = iv[0];
+                        iv[0] = iv[2];
+                        iv[2] = 0;
+                }
+        }
+
         txhdr = (struct p54_tx_data *) skb_push(skb, sizeof(*txhdr) + padding);
         hdr = (struct p54_hdr *) skb_push(skb, sizeof(*hdr));
 
         if (padding)
                 hdr_flags |= P54_HDR_FLAG_DATA_ALIGN;
-        hdr->len = cpu_to_le16(len);
         hdr->type = cpu_to_le16(aid);
         hdr->rts_tries = info->control.rates[0].count;
 
@@ -1217,10 +1265,27 @@ static int p54_tx(struct ieee80211_hw *dev, struct sk_buff *skb)
         /* TODO: enable bursting */
         hdr->flags = cpu_to_le16(hdr_flags);
         hdr->tries = ridx;
-        txhdr->crypt_offset = 0;
         txhdr->rts_rate_idx = 0;
-        txhdr->key_type = 0;
-        txhdr->key_len = 0;
+        if (info->control.hw_key) {
+                crypt_offset += info->control.hw_key->iv_len;
+                txhdr->key_type = p54_convert_algo(info->control.hw_key->alg);
+                txhdr->key_len = min((u8)16, info->control.hw_key->keylen);
+                memcpy(txhdr->key, info->control.hw_key->key, txhdr->key_len);
+                if (info->control.hw_key->alg == ALG_TKIP) {
+                        if (unlikely(skb_tailroom(skb) < 12))
+                                goto err;
+                        /* reserve space for the MIC key */
+                        len += 8;
+                        memcpy(skb_put(skb, 8), &(info->control.hw_key->key
+                                [NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY]), 8);
+                }
+                /* reserve some space for ICV */
+                len += info->control.hw_key->icv_len;
+        } else {
+                txhdr->key_type = 0;
+                txhdr->key_len = 0;
+        }
+        txhdr->crypt_offset = crypt_offset;
         txhdr->hw_queue = queue;
         if (current_queue)
                 txhdr->backlog = current_queue->len;
@@ -1234,17 +1299,20 @@ static int p54_tx(struct ieee80211_hw *dev, struct sk_buff *skb)
         if (padding)
                 txhdr->align[0] = padding;
 
+        hdr->len = cpu_to_le16(len);
         /* modifies skb->cb and with it info, so must be last! */
-        if (unlikely(p54_assign_address(dev, skb, hdr, skb->len + tim_len))) {
-                skb_pull(skb, sizeof(*hdr) + sizeof(*txhdr) + padding);
-                if (current_queue) {
-                        current_queue->len--;
-                        current_queue->count--;
-                }
-                return NETDEV_TX_BUSY;
-        }
+        if (unlikely(p54_assign_address(dev, skb, hdr, skb->len + tim_len)))
+                goto err;
         priv->tx(dev, skb, 0);
         return 0;
+
+ err:
+        skb_pull(skb, sizeof(*hdr) + sizeof(*txhdr) + padding);
+        if (current_queue) {
+                current_queue->len--;
+                current_queue->count--;
+        }
+        return NETDEV_TX_BUSY;
 }
 
 static int p54_setup_mac(struct ieee80211_hw *dev, u16 mode, const u8 *bssid)
@@ -1848,6 +1916,90 @@ static void p54_bss_info_changed(struct ieee80211_hw *dev,
 
 }
 
+static int p54_set_key(struct ieee80211_hw *dev, enum set_key_cmd cmd,
+                       const u8 *local_address, const u8 *address,
+                       struct ieee80211_key_conf *key)
+{
+        struct p54_common *priv = dev->priv;
+        struct sk_buff *skb;
+        struct p54_keycache *rxkey;
+        u8 algo = 0;
+
+        if (modparam_nohwcrypt)
+                return -EOPNOTSUPP;
+
+        if (cmd == DISABLE_KEY)
+                algo = 0;
+        else {
+                switch (key->alg) {
+                case ALG_TKIP:
+                        if (!(priv->privacy_caps & (BR_DESC_PRIV_CAP_MICHAEL |
+                              BR_DESC_PRIV_CAP_TKIP)))
+                                return -EOPNOTSUPP;
+                        key->flags |= IEEE80211_KEY_FLAG_GENERATE_IV;
+                        algo = P54_CRYPTO_TKIPMICHAEL;
+                        break;
+                case ALG_WEP:
+                        if (!(priv->privacy_caps & BR_DESC_PRIV_CAP_WEP))
+                                return -EOPNOTSUPP;
+                        key->flags |= IEEE80211_KEY_FLAG_GENERATE_IV;
+                        algo = P54_CRYPTO_WEP;
+                        break;
+                case ALG_CCMP:
+                        if (!(priv->privacy_caps & BR_DESC_PRIV_CAP_AESCCMP))
+                                return -EOPNOTSUPP;
+                        key->flags |= IEEE80211_KEY_FLAG_GENERATE_IV;
+                        algo = P54_CRYPTO_AESCCMP;
+                        break;
+                default:
+                        return -EINVAL;
+                }
+        }
+
+        if (key->keyidx > priv->rx_keycache_size) {
+                /*
+                 * The device supports the choosen algorithm, but the firmware
+                 * does not provide enough key slots to store all of them.
+                 * So, incoming frames have to be decoded by the mac80211 stack,
+                 * but we can still offload encryption for outgoing frames.
+                 */
+
+                return 0;
+        }
+
+        mutex_lock(&priv->conf_mutex);
+        skb = p54_alloc_skb(dev, P54_HDR_FLAG_CONTROL_OPSET, sizeof(*rxkey) +
+                        sizeof(struct p54_hdr), P54_CONTROL_TYPE_RX_KEYCACHE,
+                        GFP_ATOMIC);
+        if (!skb) {
+                mutex_unlock(&priv->conf_mutex);
+                return -ENOMEM;
+        }
+
+        /* TODO: some devices have 4 more free slots for rx keys */
+        rxkey = (struct p54_keycache *)skb_put(skb, sizeof(*rxkey));
+        rxkey->entry = key->keyidx;
+        rxkey->key_id = key->keyidx;
+        rxkey->key_type = algo;
+        if (address)
+                memcpy(rxkey->mac, address, ETH_ALEN);
+        else
+                memset(rxkey->mac, ~0, ETH_ALEN);
+        if (key->alg != ALG_TKIP) {
+                rxkey->key_len = min((u8)16, key->keylen);
+                memcpy(rxkey->key, key->key, rxkey->key_len);
+        } else {
+                rxkey->key_len = 24;
+                memcpy(rxkey->key, key->key, 16);
+                memcpy(&(rxkey->key[16]), &(key->key
+                        [NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY]), 8);
+        }
+
+        priv->tx(dev, skb, 1);
+        mutex_unlock(&priv->conf_mutex);
+        return 0;
+}
+
 static const struct ieee80211_ops p54_ops = {
         .tx                     = p54_tx,
         .start                  = p54_start,
@@ -1857,6 +2009,7 @@ static const struct ieee80211_ops p54_ops = {
         .set_tim                = p54_set_tim,
         .sta_notify_ps          = p54_sta_notify_ps,
         .sta_notify             = p54_sta_notify,
+        .set_key                = p54_set_key,
         .config                 = p54_config,
         .config_interface       = p54_config_interface,
         .bss_info_changed       = p54_bss_info_changed,