iwlwifi: move TX code into iwl-tx.c

This patch moves the sending part of the TX code into iwl-tx.c
including sending host commands.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 662 insertions, 0 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-tx.c b/drivers/net/wireless/iwlwifi/iwl-tx.c
index 870d257bded..a37ced58c66 100644
--- a/drivers/net/wireless/iwlwifi/iwl-tx.c
+++ b/drivers/net/wireless/iwlwifi/iwl-tx.c
@@ -27,6 +27,7 @@
  *
  *****************************************************************************/
 
+#include <linux/etherdevice.h>
 #include <net/mac80211.h>
 #include "iwl-eeprom.h"
 #include "iwl-dev.h"
@@ -95,6 +96,89 @@ int iwl_hw_txq_free_tfd(struct iwl_priv *priv, struct iwl_tx_queue *txq)
 }
 EXPORT_SYMBOL(iwl_hw_txq_free_tfd);
 
+
+int iwl_hw_txq_attach_buf_to_tfd(struct iwl_priv *priv, void *ptr,
+				 dma_addr_t addr, u16 len)
+{
+	int index, is_odd;
+	struct iwl_tfd_frame *tfd = ptr;
+	u32 num_tbs = IWL_GET_BITS(*tfd, num_tbs);
+
+	/* Each TFD can point to a maximum 20 Tx buffers */
+	if ((num_tbs >= MAX_NUM_OF_TBS) || (num_tbs < 0)) {
+		IWL_ERROR("Error can not send more than %d chunks\n",
+			  MAX_NUM_OF_TBS);
+		return -EINVAL;
+	}
+
+	index = num_tbs / 2;
+	is_odd = num_tbs & 0x1;
+
+	if (!is_odd) {
+		tfd->pa[index].tb1_addr = cpu_to_le32(addr);
+		IWL_SET_BITS(tfd->pa[index], tb1_addr_hi,
+			     iwl_get_dma_hi_address(addr));
+		IWL_SET_BITS(tfd->pa[index], tb1_len, len);
+	} else {
+		IWL_SET_BITS(tfd->pa[index], tb2_addr_lo16,
+			     (u32) (addr & 0xffff));
+		IWL_SET_BITS(tfd->pa[index], tb2_addr_hi20, addr >> 16);
+		IWL_SET_BITS(tfd->pa[index], tb2_len, len);
+	}
+
+	IWL_SET_BITS(*tfd, num_tbs, num_tbs + 1);
+
+	return 0;
+}
+EXPORT_SYMBOL(iwl_hw_txq_attach_buf_to_tfd);
+
+/**
+ * iwl_txq_update_write_ptr - Send new write index to hardware
+ */
+int iwl_txq_update_write_ptr(struct iwl_priv *priv, struct iwl_tx_queue *txq)
+{
+	u32 reg = 0;
+	int ret = 0;
+	int txq_id = txq->q.id;
+
+	if (txq->need_update == 0)
+		return ret;
+
+	/* if we're trying to save power */
+	if (test_bit(STATUS_POWER_PMI, &priv->status)) {
+		/* wake up nic if it's powered down ...
+		 * uCode will wake up, and interrupt us again, so next
+		 * time we'll skip this part. */
+		reg = iwl_read32(priv, CSR_UCODE_DRV_GP1);
+
+		if (reg & CSR_UCODE_DRV_GP1_BIT_MAC_SLEEP) {
+			IWL_DEBUG_INFO("Requesting wakeup, GP1 = 0x%x\n", reg);
+			iwl_set_bit(priv, CSR_GP_CNTRL,
+				    CSR_GP_CNTRL_REG_FLAG_MAC_ACCESS_REQ);
+			return ret;
+		}
+
+		/* restore this queue's parameters in nic hardware. */
+		ret = iwl_grab_nic_access(priv);
+		if (ret)
+			return ret;
+		iwl_write_direct32(priv, HBUS_TARG_WRPTR,
+				     txq->q.write_ptr | (txq_id << 8));
+		iwl_release_nic_access(priv);
+
+	/* else not in power-save mode, uCode will never sleep when we're
+	 * trying to tx (during RFKILL, we're not trying to tx). */
+	} else
+		iwl_write32(priv, HBUS_TARG_WRPTR,
+			    txq->q.write_ptr | (txq_id << 8));
+
+	txq->need_update = 0;
+
+	return ret;
+}
+EXPORT_SYMBOL(iwl_txq_update_write_ptr);
+
+
 /**
  * iwl_tx_queue_free - Deallocate DMA queue.
  * @txq: Transmit queue to deallocate.
@@ -137,6 +221,47 @@ static void iwl_tx_queue_free(struct iwl_priv *priv, struct iwl_tx_queue *txq)
 	memset(txq, 0, sizeof(*txq));
 }
 
+/*************** DMA-QUEUE-GENERAL-FUNCTIONS  *****
+ * DMA services
+ *
+ * Theory of operation
+ *
+ * A Tx or Rx queue resides in host DRAM, and is comprised of a circular buffer
+ * of buffer descriptors, each of which points to one or more data buffers for
+ * the device to read from or fill.  Driver and device exchange status of each
+ * queue via "read" and "write" pointers.  Driver keeps minimum of 2 empty
+ * entries in each circular buffer, to protect against confusing empty and full
+ * queue states.
+ *
+ * The device reads or writes the data in the queues via the device's several
+ * DMA/FIFO channels.  Each queue is mapped to a single DMA channel.
+ *
+ * For Tx queue, there are low mark and high mark limits. If, after queuing
+ * the packet for Tx, free space become < low mark, Tx queue stopped. When
+ * reclaiming packets (on 'tx done IRQ), if free space become > high mark,
+ * Tx queue resumed.
+ *
+ * See more detailed info in iwl-4965-hw.h.
+ ***************************************************/
+
+int iwl_queue_space(const struct iwl_queue *q)
+{
+	int s = q->read_ptr - q->write_ptr;
+
+	if (q->read_ptr > q->write_ptr)
+		s -= q->n_bd;
+
+	if (s <= 0)
+		s += q->n_window;
+	/* keep some reserve to not confuse empty and full situations */
+	s -= 2;
+	if (s < 0)
+		s = 0;
+	return s;
+}
+EXPORT_SYMBOL(iwl_queue_space);
+
+
 /**
  * iwl_hw_txq_ctx_free - Free TXQ Context
  *
@@ -371,3 +496,540 @@ int iwl_txq_ctx_reset(struct iwl_priv *priv)
  error_kw:
 	return ret;
 }
+
+/*
+ * handle build REPLY_TX command notification.
+ */
+static void iwl_tx_cmd_build_basic(struct iwl_priv *priv,
+				  struct iwl_tx_cmd *tx_cmd,
+				  struct ieee80211_tx_control *ctrl,
+				  struct ieee80211_hdr *hdr,
+				  int is_unicast, u8 std_id)
+{
+	u16 fc = le16_to_cpu(hdr->frame_control);
+	__le32 tx_flags = tx_cmd->tx_flags;
+
+	tx_cmd->stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
+	if (!(ctrl->flags & IEEE80211_TXCTL_NO_ACK)) {
+		tx_flags |= TX_CMD_FLG_ACK_MSK;
+		if ((fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_MGMT)
+			tx_flags |= TX_CMD_FLG_SEQ_CTL_MSK;
+		if (ieee80211_is_probe_response(fc) &&
+		    !(le16_to_cpu(hdr->seq_ctrl) & 0xf))
+			tx_flags |= TX_CMD_FLG_TSF_MSK;
+	} else {
+		tx_flags &= (~TX_CMD_FLG_ACK_MSK);
+		tx_flags |= TX_CMD_FLG_SEQ_CTL_MSK;
+	}
+
+	if (ieee80211_is_back_request(fc))
+		tx_flags |= TX_CMD_FLG_ACK_MSK | TX_CMD_FLG_IMM_BA_RSP_MASK;
+
+
+	tx_cmd->sta_id = std_id;
+	if (ieee80211_get_morefrag(hdr))
+		tx_flags |= TX_CMD_FLG_MORE_FRAG_MSK;
+
+	if (ieee80211_is_qos_data(fc)) {
+		u8 *qc = ieee80211_get_qos_ctrl(hdr, ieee80211_get_hdrlen(fc));
+		tx_cmd->tid_tspec = qc[0] & 0xf;
+		tx_flags &= ~TX_CMD_FLG_SEQ_CTL_MSK;
+	} else {
+		tx_flags |= TX_CMD_FLG_SEQ_CTL_MSK;
+	}
+
+	if (ctrl->flags & IEEE80211_TXCTL_USE_RTS_CTS) {
+		tx_flags |= TX_CMD_FLG_RTS_MSK;
+		tx_flags &= ~TX_CMD_FLG_CTS_MSK;
+	} else if (ctrl->flags & IEEE80211_TXCTL_USE_CTS_PROTECT) {
+		tx_flags &= ~TX_CMD_FLG_RTS_MSK;
+		tx_flags |= TX_CMD_FLG_CTS_MSK;
+	}
+
+	if ((tx_flags & TX_CMD_FLG_RTS_MSK) || (tx_flags & TX_CMD_FLG_CTS_MSK))
+		tx_flags |= TX_CMD_FLG_FULL_TXOP_PROT_MSK;
+
+	tx_flags &= ~(TX_CMD_FLG_ANT_SEL_MSK);
+	if ((fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_MGMT) {
+		if ((fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_ASSOC_REQ ||
+		    (fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_REASSOC_REQ)
+			tx_cmd->timeout.pm_frame_timeout = cpu_to_le16(3);
+		else
+			tx_cmd->timeout.pm_frame_timeout = cpu_to_le16(2);
+	} else {
+		tx_cmd->timeout.pm_frame_timeout = 0;
+	}
+
+	tx_cmd->driver_txop = 0;
+	tx_cmd->tx_flags = tx_flags;
+	tx_cmd->next_frame_len = 0;
+}
+
+#define RTS_HCCA_RETRY_LIMIT		3
+#define RTS_DFAULT_RETRY_LIMIT		60
+
+static void iwl_tx_cmd_build_rate(struct iwl_priv *priv,
+			      struct iwl_tx_cmd *tx_cmd,
+			      struct ieee80211_tx_control *ctrl,
+			      u16 fc, int sta_id,
+			      int is_hcca)
+{
+	u8 rts_retry_limit = 0;
+	u8 data_retry_limit = 0;
+	u8 rate_plcp;
+	u16 rate_flags = 0;
+	int rate_idx = min(ctrl->tx_rate->hw_value & 0xffff, IWL_RATE_COUNT - 1);
+
+	rate_plcp = iwl_rates[rate_idx].plcp;
+
+	rts_retry_limit = (is_hcca) ?
+	    RTS_HCCA_RETRY_LIMIT : RTS_DFAULT_RETRY_LIMIT;
+
+	if ((rate_idx >= IWL_FIRST_CCK_RATE) && (rate_idx <= IWL_LAST_CCK_RATE))
+		rate_flags |= RATE_MCS_CCK_MSK;
+
+
+	if (ieee80211_is_probe_response(fc)) {
+		data_retry_limit = 3;
+		if (data_retry_limit < rts_retry_limit)
+			rts_retry_limit = data_retry_limit;
+	} else
+		data_retry_limit = IWL_DEFAULT_TX_RETRY;
+
+	if (priv->data_retry_limit != -1)
+		data_retry_limit = priv->data_retry_limit;
+
+
+	if (ieee80211_is_data(fc)) {
+		tx_cmd->initial_rate_index = 0;
+		tx_cmd->tx_flags |= TX_CMD_FLG_STA_RATE_MSK;
+	} else {
+		switch (fc & IEEE80211_FCTL_STYPE) {
+		case IEEE80211_STYPE_AUTH:
+		case IEEE80211_STYPE_DEAUTH:
+		case IEEE80211_STYPE_ASSOC_REQ:
+		case IEEE80211_STYPE_REASSOC_REQ:
+			if (tx_cmd->tx_flags & TX_CMD_FLG_RTS_MSK) {
+				tx_cmd->tx_flags &= ~TX_CMD_FLG_RTS_MSK;
+				tx_cmd->tx_flags |= TX_CMD_FLG_CTS_MSK;
+			}
+			break;
+		default:
+			break;
+		}
+
+		/* Alternate between antenna A and B for successive frames */
+		if (priv->use_ant_b_for_management_frame) {
+			priv->use_ant_b_for_management_frame = 0;
+			rate_flags |= RATE_MCS_ANT_B_MSK;
+		} else {
+			priv->use_ant_b_for_management_frame = 1;
+			rate_flags |= RATE_MCS_ANT_A_MSK;
+		}
+	}
+
+	tx_cmd->rts_retry_limit = rts_retry_limit;
+	tx_cmd->data_retry_limit = data_retry_limit;
+	tx_cmd->rate_n_flags = iwl4965_hw_set_rate_n_flags(rate_plcp, rate_flags);
+}
+
+static void iwl_tx_cmd_build_hwcrypto(struct iwl_priv *priv,
+				      struct ieee80211_tx_control *ctl,
+				      struct iwl_tx_cmd *tx_cmd,
+				      struct sk_buff *skb_frag,
+				      int sta_id)
+{
+	struct iwl_hw_key *keyinfo = &priv->stations[sta_id].keyinfo;
+	struct iwl_wep_key *wepkey;
+	int keyidx = 0;
+
+	BUG_ON(ctl->hw_key->hw_key_idx > 3);
+
+	switch (keyinfo->alg) {
+	case ALG_CCMP:
+		tx_cmd->sec_ctl = TX_CMD_SEC_CCM;
+		memcpy(tx_cmd->key, keyinfo->key, keyinfo->keylen);
+		if (ctl->flags & IEEE80211_TXCTL_AMPDU)
+			tx_cmd->tx_flags |= TX_CMD_FLG_AGG_CCMP_MSK;
+		IWL_DEBUG_TX("tx_cmd with aes hwcrypto\n");
+		break;
+
+	case ALG_TKIP:
+		tx_cmd->sec_ctl = TX_CMD_SEC_TKIP;
+		ieee80211_get_tkip_key(keyinfo->conf, skb_frag,
+			IEEE80211_TKIP_P2_KEY, tx_cmd->key);
+		IWL_DEBUG_TX("tx_cmd with tkip hwcrypto\n");
+		break;
+
+	case ALG_WEP:
+		wepkey = &priv->wep_keys[ctl->hw_key->hw_key_idx];
+		tx_cmd->sec_ctl = 0;
+		if (priv->default_wep_key) {
+			/* the WEP key was sent as static */
+			keyidx = ctl->hw_key->hw_key_idx;
+			memcpy(&tx_cmd->key[3], wepkey->key,
+							wepkey->key_size);
+			if (wepkey->key_size == WEP_KEY_LEN_128)
+				tx_cmd->sec_ctl |= TX_CMD_SEC_KEY128;
+		} else {
+			/* the WEP key was sent as dynamic */
+			keyidx = keyinfo->keyidx;
+			memcpy(&tx_cmd->key[3], keyinfo->key,
+							keyinfo->keylen);
+			if (keyinfo->keylen == WEP_KEY_LEN_128)
+				tx_cmd->sec_ctl |= TX_CMD_SEC_KEY128;
+		}
+
+		tx_cmd->sec_ctl |= (TX_CMD_SEC_WEP |
+			(keyidx & TX_CMD_SEC_MSK) << TX_CMD_SEC_SHIFT);
+
+		IWL_DEBUG_TX("Configuring packet for WEP encryption "
+			     "with key %d\n", keyidx);
+		break;
+
+	default:
+		printk(KERN_ERR "Unknown encode alg %d\n", keyinfo->alg);
+		break;
+	}
+}
+
+static void iwl_update_tx_stats(struct iwl_priv *priv, u16 fc, u16 len)
+{
+	/* 0 - mgmt, 1 - cnt, 2 - data */
+	int idx = (fc & IEEE80211_FCTL_FTYPE) >> 2;
+	priv->tx_stats[idx].cnt++;
+	priv->tx_stats[idx].bytes += len;
+}
+
+/*
+ * start REPLY_TX command process
+ */
+int iwl_tx_skb(struct iwl_priv *priv,
+		struct sk_buff *skb, struct ieee80211_tx_control *ctl)
+{
+	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
+	struct iwl_tfd_frame *tfd;
+	u32 *control_flags;
+	int txq_id = ctl->queue;
+	struct iwl_tx_queue *txq = NULL;
+	struct iwl_queue *q = NULL;
+	dma_addr_t phys_addr;
+	dma_addr_t txcmd_phys;
+	dma_addr_t scratch_phys;
+	struct iwl_cmd *out_cmd = NULL;
+	struct iwl_tx_cmd *tx_cmd;
+	u16 len, idx, len_org;
+	u16 seq_number = 0;
+	u8 id, hdr_len, unicast;
+	u8 sta_id;
+	u16 fc;
+	u8 wait_write_ptr = 0;
+	u8 tid = 0;
+	u8 *qc = NULL;
+	unsigned long flags;
+	int ret;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	if (iwl_is_rfkill(priv)) {
+		IWL_DEBUG_DROP("Dropping - RF KILL\n");
+		goto drop_unlock;
+	}
+
+	if (!priv->vif) {
+		IWL_DEBUG_DROP("Dropping - !priv->vif\n");
+		goto drop_unlock;
+	}
+
+	if ((ctl->tx_rate->hw_value & 0xFF) == IWL_INVALID_RATE) {
+		IWL_ERROR("ERROR: No TX rate available.\n");
+		goto drop_unlock;
+	}
+
+	unicast = !is_multicast_ether_addr(hdr->addr1);
+	id = 0;
+
+	fc = le16_to_cpu(hdr->frame_control);
+
+#ifdef CONFIG_IWLWIFI_DEBUG
+	if (ieee80211_is_auth(fc))
+		IWL_DEBUG_TX("Sending AUTH frame\n");
+	else if (ieee80211_is_assoc_request(fc))
+		IWL_DEBUG_TX("Sending ASSOC frame\n");
+	else if (ieee80211_is_reassoc_request(fc))
+		IWL_DEBUG_TX("Sending REASSOC frame\n");
+#endif
+
+	/* drop all data frame if we are not associated */
+	if (((fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA) &&
+	   (!iwl_is_associated(priv) ||
+	    ((priv->iw_mode == IEEE80211_IF_TYPE_STA) && !priv->assoc_id) ||
+	    !priv->assoc_station_added)) {
+		IWL_DEBUG_DROP("Dropping - !iwl_is_associated\n");
+		goto drop_unlock;
+	}
+
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	hdr_len = ieee80211_get_hdrlen(fc);
+
+	/* Find (or create) index into station table for destination station */
+	sta_id = iwl_get_sta_id(priv, hdr);
+	if (sta_id == IWL_INVALID_STATION) {
+		DECLARE_MAC_BUF(mac);
+
+		IWL_DEBUG_DROP("Dropping - INVALID STATION: %s\n",
+			       print_mac(mac, hdr->addr1));
+		goto drop;
+	}
+
+	IWL_DEBUG_TX("station Id %d\n", sta_id);
+
+	if (ieee80211_is_qos_data(fc)) {
+		qc = ieee80211_get_qos_ctrl(hdr, hdr_len);
+		tid = qc[0] & 0xf;
+		seq_number = priv->stations[sta_id].tid[tid].seq_number &
+				IEEE80211_SCTL_SEQ;
+		hdr->seq_ctrl = cpu_to_le16(seq_number) |
+			(hdr->seq_ctrl &
+				__constant_cpu_to_le16(IEEE80211_SCTL_FRAG));
+		seq_number += 0x10;
+#ifdef CONFIG_IWL4965_HT
+		/* aggregation is on for this <sta,tid> */
+		if (ctl->flags & IEEE80211_TXCTL_AMPDU)
+			txq_id = priv->stations[sta_id].tid[tid].agg.txq_id;
+		priv->stations[sta_id].tid[tid].tfds_in_queue++;
+#endif /* CONFIG_IWL4965_HT */
+	}
+
+	/* Descriptor for chosen Tx queue */
+	txq = &priv->txq[txq_id];
+	q = &txq->q;
+
+	spin_lock_irqsave(&priv->lock, flags);
+
+	/* Set up first empty TFD within this queue's circular TFD buffer */
+	tfd = &txq->bd[q->write_ptr];
+	memset(tfd, 0, sizeof(*tfd));
+	control_flags = (u32 *) tfd;
+	idx = get_cmd_index(q, q->write_ptr, 0);
+
+	/* Set up driver data for this TFD */
+	memset(&(txq->txb[q->write_ptr]), 0, sizeof(struct iwl_tx_info));
+	txq->txb[q->write_ptr].skb[0] = skb;
+	memcpy(&(txq->txb[q->write_ptr].status.control),
+	       ctl, sizeof(struct ieee80211_tx_control));
+
+	/* Set up first empty entry in queue's array of Tx/cmd buffers */
+	out_cmd = &txq->cmd[idx];
+	tx_cmd = &out_cmd->cmd.tx;
+	memset(&out_cmd->hdr, 0, sizeof(out_cmd->hdr));
+	memset(tx_cmd, 0, sizeof(struct iwl_tx_cmd));
+
+	/*
+	 * Set up the Tx-command (not MAC!) header.
+	 * Store the chosen Tx queue and TFD index within the sequence field;
+	 * after Tx, uCode's Tx response will return this value so driver can
+	 * locate the frame within the tx queue and do post-tx processing.
+	 */
+	out_cmd->hdr.cmd = REPLY_TX;
+	out_cmd->hdr.sequence = cpu_to_le16((u16)(QUEUE_TO_SEQ(txq_id) |
+				INDEX_TO_SEQ(q->write_ptr)));
+
+	/* Copy MAC header from skb into command buffer */
+	memcpy(tx_cmd->hdr, hdr, hdr_len);
+
+	/*
+	 * Use the first empty entry in this queue's command buffer array
+	 * to contain the Tx command and MAC header concatenated together
+	 * (payload data will be in another buffer).
+	 * Size of this varies, due to varying MAC header length.
+	 * If end is not dword aligned, we'll have 2 extra bytes at the end
+	 * of the MAC header (device reads on dword boundaries).
+	 * We'll tell device about this padding later.
+	 */
+	len = sizeof(struct iwl_tx_cmd) +
+		sizeof(struct iwl_cmd_header) + hdr_len;
+
+	len_org = len;
+	len = (len + 3) & ~3;
+
+	if (len_org != len)
+		len_org = 1;
+	else
+		len_org = 0;
+
+	/* Physical address of this Tx command's header (not MAC header!),
+	 * within command buffer array. */
+	txcmd_phys = txq->dma_addr_cmd + sizeof(struct iwl_cmd) * idx +
+		     offsetof(struct iwl_cmd, hdr);
+
+	/* Add buffer containing Tx command and MAC(!) header to TFD's
+	 * first entry */
+	iwl_hw_txq_attach_buf_to_tfd(priv, tfd, txcmd_phys, len);
+
+	if (!(ctl->flags & IEEE80211_TXCTL_DO_NOT_ENCRYPT))
+		iwl_tx_cmd_build_hwcrypto(priv, ctl, tx_cmd, skb, sta_id);
+
+	/* Set up TFD's 2nd entry to point directly to remainder of skb,
+	 * if any (802.11 null frames have no payload). */
+	len = skb->len - hdr_len;
+	if (len) {
+		phys_addr = pci_map_single(priv->pci_dev, skb->data + hdr_len,
+					   len, PCI_DMA_TODEVICE);
+		iwl_hw_txq_attach_buf_to_tfd(priv, tfd, phys_addr, len);
+	}
+
+	/* Tell NIC about any 2-byte padding after MAC header */
+	if (len_org)
+		tx_cmd->tx_flags |= TX_CMD_FLG_MH_PAD_MSK;
+
+	/* Total # bytes to be transmitted */
+	len = (u16)skb->len;
+	tx_cmd->len = cpu_to_le16(len);
+	/* TODO need this for burst mode later on */
+	iwl_tx_cmd_build_basic(priv, tx_cmd, ctl, hdr, unicast, sta_id);
+
+	/* set is_hcca to 0; it probably will never be implemented */
+	iwl_tx_cmd_build_rate(priv, tx_cmd, ctl, fc, sta_id, 0);
+
+	iwl_update_tx_stats(priv, fc, len);
+
+	scratch_phys = txcmd_phys + sizeof(struct iwl_cmd_header) +
+		offsetof(struct iwl_tx_cmd, scratch);
+	tx_cmd->dram_lsb_ptr = cpu_to_le32(scratch_phys);
+	tx_cmd->dram_msb_ptr = iwl_get_dma_hi_address(scratch_phys);
+
+	if (!ieee80211_get_morefrag(hdr)) {
+		txq->need_update = 1;
+		if (qc)
+			priv->stations[sta_id].tid[tid].seq_number = seq_number;
+	} else {
+		wait_write_ptr = 1;
+		txq->need_update = 0;
+	}
+
+	iwl_print_hex_dump(priv, IWL_DL_TX, (u8 *)tx_cmd, sizeof(*tx_cmd));
+
+	iwl_print_hex_dump(priv, IWL_DL_TX, (u8 *)tx_cmd->hdr, hdr_len);
+
+	/* Set up entry for this TFD in Tx byte-count array */
+	priv->cfg->ops->lib->txq_update_byte_cnt_tbl(priv, txq, len);
+
+	/* Tell device the write index *just past* this latest filled TFD */
+	q->write_ptr = iwl_queue_inc_wrap(q->write_ptr, q->n_bd);
+	ret = iwl_txq_update_write_ptr(priv, txq);
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	if (ret)
+		return ret;
+
+	if ((iwl_queue_space(q) < q->high_mark)
+	    && priv->mac80211_registered) {
+		if (wait_write_ptr) {
+			spin_lock_irqsave(&priv->lock, flags);
+			txq->need_update = 1;
+			iwl_txq_update_write_ptr(priv, txq);
+			spin_unlock_irqrestore(&priv->lock, flags);
+		}
+
+		ieee80211_stop_queue(priv->hw, ctl->queue);
+	}
+
+	return 0;
+
+drop_unlock:
+	spin_unlock_irqrestore(&priv->lock, flags);
+drop:
+	return -1;
+}
+EXPORT_SYMBOL(iwl_tx_skb);
+
+/*************** HOST COMMAND QUEUE FUNCTIONS   *****/
+
+/**
+ * iwl_enqueue_hcmd - enqueue a uCode command
+ * @priv: device private data point
+ * @cmd: a point to the ucode command structure
+ *
+ * The function returns < 0 values to indicate the operation is
+ * failed. On success, it turns the index (> 0) of command in the
+ * command queue.
+ */
+int iwl_enqueue_hcmd(struct iwl_priv *priv, struct iwl_host_cmd *cmd)
+{
+	struct iwl_tx_queue *txq = &priv->txq[IWL_CMD_QUEUE_NUM];
+	struct iwl_queue *q = &txq->q;
+	struct iwl_tfd_frame *tfd;
+	u32 *control_flags;
+	struct iwl_cmd *out_cmd;
+	u32 idx;
+	u16 fix_size;
+	dma_addr_t phys_addr;
+	int ret;
+	unsigned long flags;
+
+	cmd->len = priv->cfg->ops->utils->get_hcmd_size(cmd->id, cmd->len);
+	fix_size = (u16)(cmd->len + sizeof(out_cmd->hdr));
+
+	/* If any of the command structures end up being larger than
+	 * the TFD_MAX_PAYLOAD_SIZE, and it sent as a 'small' command then
+	 * we will need to increase the size of the TFD entries */
+	BUG_ON((fix_size > TFD_MAX_PAYLOAD_SIZE) &&
+	       !(cmd->meta.flags & CMD_SIZE_HUGE));
+
+	if (iwl_is_rfkill(priv)) {
+		IWL_DEBUG_INFO("Not sending command - RF KILL");
+		return -EIO;
+	}
+
+	if (iwl_queue_space(q) < ((cmd->meta.flags & CMD_ASYNC) ? 2 : 1)) {
+		IWL_ERROR("No space for Tx\n");
+		return -ENOSPC;
+	}
+
+	spin_lock_irqsave(&priv->hcmd_lock, flags);
+
+	tfd = &txq->bd[q->write_ptr];
+	memset(tfd, 0, sizeof(*tfd));
+
+	control_flags = (u32 *) tfd;
+
+	idx = get_cmd_index(q, q->write_ptr, cmd->meta.flags & CMD_SIZE_HUGE);
+	out_cmd = &txq->cmd[idx];
+
+	out_cmd->hdr.cmd = cmd->id;
+	memcpy(&out_cmd->meta, &cmd->meta, sizeof(cmd->meta));
+	memcpy(&out_cmd->cmd.payload, cmd->data, cmd->len);
+
+	/* At this point, the out_cmd now has all of the incoming cmd
+	 * information */
+
+	out_cmd->hdr.flags = 0;
+	out_cmd->hdr.sequence = cpu_to_le16(QUEUE_TO_SEQ(IWL_CMD_QUEUE_NUM) |
+			INDEX_TO_SEQ(q->write_ptr));
+	if (out_cmd->meta.flags & CMD_SIZE_HUGE)
+		out_cmd->hdr.sequence |= cpu_to_le16(SEQ_HUGE_FRAME);
+
+	phys_addr = txq->dma_addr_cmd + sizeof(txq->cmd[0]) * idx +
+			offsetof(struct iwl_cmd, hdr);
+	iwl_hw_txq_attach_buf_to_tfd(priv, tfd, phys_addr, fix_size);
+
+	IWL_DEBUG_HC("Sending command %s (#%x), seq: 0x%04X, "
+		     "%d bytes at %d[%d]:%d\n",
+		     get_cmd_string(out_cmd->hdr.cmd),
+		     out_cmd->hdr.cmd, le16_to_cpu(out_cmd->hdr.sequence),
+		     fix_size, q->write_ptr, idx, IWL_CMD_QUEUE_NUM);
+
+	txq->need_update = 1;
+
+	/* Set up entry in queue's byte count circular buffer */
+	priv->cfg->ops->lib->txq_update_byte_cnt_tbl(priv, txq, 0);
+
+	/* Increment and update queue's write index */
+	q->write_ptr = iwl_queue_inc_wrap(q->write_ptr, q->n_bd);
+	ret = iwl_txq_update_write_ptr(priv, txq);
+
+	spin_unlock_irqrestore(&priv->hcmd_lock, flags);
+	return ret ? ret : idx;
+}
+