iwl3945-base.c

/******************************************************************************
 *
 * Copyright(c) 2003 - 2010 Intel Corporation. All rights reserved.
 *
 * Portions of this file are derived from the ipw3945 project, as well
 * as portions of the ieee80211 subsystem header files.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA
 *
 * The full GNU General Public License is included in this distribution in the
 * file called LICENSE.
 *
 * Contact Information:
 *  Intel Linux Wireless <ilw@linux.intel.com>
 * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
 *
 *****************************************************************************/

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/pci-aspm.h>
#include <linux/slab.h>
#include <linux/dma-mapping.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/wireless.h>
#include <linux/firmware.h>
#include <linux/etherdevice.h>
#include <linux/if_arp.h>

#include <net/ieee80211_radiotap.h>
#include <net/mac80211.h>

#include <asm/div64.h>

#define DRV_NAME	"iwl3945"

#include "iwl-fh.h"
#include "iwl-3945-fh.h"
#include "iwl-commands.h"
#include "iwl-sta.h"
#include "iwl-3945.h"
#include "iwl-core.h"
#include "iwl-helpers.h"
#include "iwl-dev.h"
#include "iwl-spectrum.h"

/*
 * module name, copyright, version, etc.
 */

#define DRV_DESCRIPTION	\
"Intel(R) PRO/Wireless 3945ABG/BG Network Connection driver for Linux"

#ifdef CONFIG_IWLWIFI_DEBUG
#define VD "d"
#else
#define VD
#endif

/*
 * add "s" to indicate spectrum measurement included.
 * we add it here to be consistent with previous releases in which
 * this was configurable.
 */
#define DRV_VERSION  IWLWIFI_VERSION VD "s"
#define DRV_COPYRIGHT	"Copyright(c) 2003-2010 Intel Corporation"
#define DRV_AUTHOR     "<ilw@linux.intel.com>"

MODULE_DESCRIPTION(DRV_DESCRIPTION);
MODULE_VERSION(DRV_VERSION);
MODULE_AUTHOR(DRV_COPYRIGHT " " DRV_AUTHOR);
MODULE_LICENSE("GPL");

 /* module parameters */
struct iwl_mod_params iwl3945_mod_params = {
	.sw_crypto = 1,
	.restart_fw = 1,
	/* the rest are 0 by default */
};

/**
 * iwl3945_get_antenna_flags - Get antenna flags for RXON command
 * @priv: eeprom and antenna fields are used to determine antenna flags
 *
 * priv->eeprom39  is used to determine if antenna AUX/MAIN are reversed
 * iwl3945_mod_params.antenna specifies the antenna diversity mode:
 *
 * IWL_ANTENNA_DIVERSITY - NIC selects best antenna by itself
 * IWL_ANTENNA_MAIN      - Force MAIN antenna
 * IWL_ANTENNA_AUX       - Force AUX antenna
 */
__le32 iwl3945_get_antenna_flags(const struct iwl_priv *priv)
{
	struct iwl3945_eeprom *eeprom = (struct iwl3945_eeprom *)priv->eeprom;

	switch (iwl3945_mod_params.antenna) {
	case IWL_ANTENNA_DIVERSITY:
		return 0;

	case IWL_ANTENNA_MAIN:
		if (eeprom->antenna_switch_type)
			return RXON_FLG_DIS_DIV_MSK | RXON_FLG_ANT_B_MSK;
		return RXON_FLG_DIS_DIV_MSK | RXON_FLG_ANT_A_MSK;

	case IWL_ANTENNA_AUX:
		if (eeprom->antenna_switch_type)
			return RXON_FLG_DIS_DIV_MSK | RXON_FLG_ANT_A_MSK;
		return RXON_FLG_DIS_DIV_MSK | RXON_FLG_ANT_B_MSK;
	}

	/* bad antenna selector value */
	IWL_ERR(priv, "Bad antenna selector value (0x%x)\n",
		iwl3945_mod_params.antenna);

	return 0;		/* "diversity" is default if error */
}

static int iwl3945_set_ccmp_dynamic_key_info(struct iwl_priv *priv,
				   struct ieee80211_key_conf *keyconf,
				   u8 sta_id)
{
	unsigned long flags;
	__le16 key_flags = 0;
	int ret;

	key_flags |= (STA_KEY_FLG_CCMP | STA_KEY_FLG_MAP_KEY_MSK);
	key_flags |= cpu_to_le16(keyconf->keyidx << STA_KEY_FLG_KEYID_POS);

	if (sta_id == priv->hw_params.bcast_sta_id)
		key_flags |= STA_KEY_MULTICAST_MSK;

	keyconf->flags |= IEEE80211_KEY_FLAG_GENERATE_IV;
	keyconf->hw_key_idx = keyconf->keyidx;
	key_flags &= ~STA_KEY_FLG_INVALID;

	spin_lock_irqsave(&priv->sta_lock, flags);
	priv->stations[sta_id].keyinfo.cipher = keyconf->cipher;
	priv->stations[sta_id].keyinfo.keylen = keyconf->keylen;
	memcpy(priv->stations[sta_id].keyinfo.key, keyconf->key,
	       keyconf->keylen);

	memcpy(priv->stations[sta_id].sta.key.key, keyconf->key,
	       keyconf->keylen);

	if ((priv->stations[sta_id].sta.key.key_flags & STA_KEY_FLG_ENCRYPT_MSK)
			== STA_KEY_FLG_NO_ENC)
		priv->stations[sta_id].sta.key.key_offset =
				 iwl_get_free_ucode_key_index(priv);
	/* else, we are overriding an existing key => no need to allocated room
	* in uCode. */

	WARN(priv->stations[sta_id].sta.key.key_offset == WEP_INVALID_OFFSET,
		"no space for a new key");

	priv->stations[sta_id].sta.key.key_flags = key_flags;
	priv->stations[sta_id].sta.sta.modify_mask = STA_MODIFY_KEY_MASK;
	priv->stations[sta_id].sta.mode = STA_CONTROL_MODIFY_MSK;

	IWL_DEBUG_INFO(priv, "hwcrypto: modify ucode station key info\n");

	ret = iwl_send_add_sta(priv, &priv->stations[sta_id].sta, CMD_ASYNC);

	spin_unlock_irqrestore(&priv->sta_lock, flags);

	return ret;
}

static int iwl3945_set_tkip_dynamic_key_info(struct iwl_priv *priv,
				  struct ieee80211_key_conf *keyconf,
				  u8 sta_id)
{
	return -EOPNOTSUPP;
}

static int iwl3945_set_wep_dynamic_key_info(struct iwl_priv *priv,
				  struct ieee80211_key_conf *keyconf,
				  u8 sta_id)
{
	return -EOPNOTSUPP;
}

static int iwl3945_clear_sta_key_info(struct iwl_priv *priv, u8 sta_id)
{
	unsigned long flags;
	struct iwl_addsta_cmd sta_cmd;

	spin_lock_irqsave(&priv->sta_lock, flags);
	memset(&priv->stations[sta_id].keyinfo, 0, sizeof(struct iwl_hw_key));
	memset(&priv->stations[sta_id].sta.key, 0,
		sizeof(struct iwl4965_keyinfo));
	priv->stations[sta_id].sta.key.key_flags = STA_KEY_FLG_NO_ENC;
	priv->stations[sta_id].sta.sta.modify_mask = STA_MODIFY_KEY_MASK;
	priv->stations[sta_id].sta.mode = STA_CONTROL_MODIFY_MSK;
	memcpy(&sta_cmd, &priv->stations[sta_id].sta, sizeof(struct iwl_addsta_cmd));
	spin_unlock_irqrestore(&priv->sta_lock, flags);

	IWL_DEBUG_INFO(priv, "hwcrypto: clear ucode station key info\n");
	return iwl_send_add_sta(priv, &sta_cmd, CMD_SYNC);
}

static int iwl3945_set_dynamic_key(struct iwl_priv *priv,
			struct ieee80211_key_conf *keyconf, u8 sta_id)
{
	int ret = 0;

	keyconf->hw_key_idx = HW_KEY_DYNAMIC;

	switch (keyconf->cipher) {
	case WLAN_CIPHER_SUITE_CCMP:
		ret = iwl3945_set_ccmp_dynamic_key_info(priv, keyconf, sta_id);
		break;
	case WLAN_CIPHER_SUITE_TKIP:
		ret = iwl3945_set_tkip_dynamic_key_info(priv, keyconf, sta_id);
		break;
	case WLAN_CIPHER_SUITE_WEP40:
	case WLAN_CIPHER_SUITE_WEP104:
		ret = iwl3945_set_wep_dynamic_key_info(priv, keyconf, sta_id);
		break;
	default:
		IWL_ERR(priv, "Unknown alg: %s alg=%x\n", __func__,
			keyconf->cipher);
		ret = -EINVAL;
	}

	IWL_DEBUG_WEP(priv, "Set dynamic key: alg=%x len=%d idx=%d sta=%d ret=%d\n",
		      keyconf->cipher, keyconf->keylen, keyconf->keyidx,
		      sta_id, ret);

	return ret;
}

static int iwl3945_remove_static_key(struct iwl_priv *priv)
{
	int ret = -EOPNOTSUPP;

	return ret;
}

static int iwl3945_set_static_key(struct iwl_priv *priv,
				struct ieee80211_key_conf *key)
{
	if (key->cipher == WLAN_CIPHER_SUITE_WEP40 ||
	    key->cipher == WLAN_CIPHER_SUITE_WEP104)
		return -EOPNOTSUPP;

	IWL_ERR(priv, "Static key invalid: cipher %x\n", key->cipher);
	return -EINVAL;
}

static void iwl3945_clear_free_frames(struct iwl_priv *priv)
{
	struct list_head *element;

	IWL_DEBUG_INFO(priv, "%d frames on pre-allocated heap on clear.\n",
		       priv->frames_count);

	while (!list_empty(&priv->free_frames)) {
		element = priv->free_frames.next;
		list_del(element);
		kfree(list_entry(element, struct iwl3945_frame, list));
		priv->frames_count--;
	}

	if (priv->frames_count) {
		IWL_WARN(priv, "%d frames still in use.  Did we lose one?\n",
			    priv->frames_count);
		priv->frames_count = 0;
	}
}

static struct iwl3945_frame *iwl3945_get_free_frame(struct iwl_priv *priv)
{
	struct iwl3945_frame *frame;
	struct list_head *element;
	if (list_empty(&priv->free_frames)) {
		frame = kzalloc(sizeof(*frame), GFP_KERNEL);
		if (!frame) {
			IWL_ERR(priv, "Could not allocate frame!\n");
			return NULL;
		}

		priv->frames_count++;
		return frame;
	}

	element = priv->free_frames.next;
	list_del(element);
	return list_entry(element, struct iwl3945_frame, list);
}

static void iwl3945_free_frame(struct iwl_priv *priv, struct iwl3945_frame *frame)
{
	memset(frame, 0, sizeof(*frame));
	list_add(&frame->list, &priv->free_frames);
}

unsigned int iwl3945_fill_beacon_frame(struct iwl_priv *priv,
				struct ieee80211_hdr *hdr,
				int left)
{

	if (!iwl_is_associated(priv) || !priv->ibss_beacon)
		return 0;

	if (priv->ibss_beacon->len > left)
		return 0;

	memcpy(hdr, priv->ibss_beacon->data, priv->ibss_beacon->len);

	return priv->ibss_beacon->len;
}

static int iwl3945_send_beacon_cmd(struct iwl_priv *priv)
{
	struct iwl3945_frame *frame;
	unsigned int frame_size;
	int rc;
	u8 rate;

	frame = iwl3945_get_free_frame(priv);

	if (!frame) {
		IWL_ERR(priv, "Could not obtain free frame buffer for beacon "
			  "command.\n");
		return -ENOMEM;
	}

	rate = iwl_rate_get_lowest_plcp(priv);

	frame_size = iwl3945_hw_get_beacon_cmd(priv, frame, rate);

	rc = iwl_send_cmd_pdu(priv, REPLY_TX_BEACON, frame_size,
			      &frame->u.cmd[0]);

	iwl3945_free_frame(priv, frame);

	return rc;
}

static void iwl3945_unset_hw_params(struct iwl_priv *priv)
{
	if (priv->_3945.shared_virt)
		dma_free_coherent(&priv->pci_dev->dev,
				  sizeof(struct iwl3945_shared),
				  priv->_3945.shared_virt,
				  priv->_3945.shared_phys);
}

static void iwl3945_build_tx_cmd_hwcrypto(struct iwl_priv *priv,
				      struct ieee80211_tx_info *info,
				      struct iwl_device_cmd *cmd,
				      struct sk_buff *skb_frag,
				      int sta_id)
{
	struct iwl3945_tx_cmd *tx_cmd = (struct iwl3945_tx_cmd *)cmd->cmd.payload;
	struct iwl_hw_key *keyinfo = &priv->stations[sta_id].keyinfo;

	tx_cmd->sec_ctl = 0;

	switch (keyinfo->cipher) {
	case WLAN_CIPHER_SUITE_CCMP:
		tx_cmd->sec_ctl = TX_CMD_SEC_CCM;
		memcpy(tx_cmd->key, keyinfo->key, keyinfo->keylen);
		IWL_DEBUG_TX(priv, "tx_cmd with AES hwcrypto\n");
		break;

	case WLAN_CIPHER_SUITE_TKIP:
		break;

	case WLAN_CIPHER_SUITE_WEP104:
		tx_cmd->sec_ctl |= TX_CMD_SEC_KEY128;
		/* fall through */
	case WLAN_CIPHER_SUITE_WEP40:
		tx_cmd->sec_ctl |= TX_CMD_SEC_WEP |
		    (info->control.hw_key->hw_key_idx & TX_CMD_SEC_MSK) << TX_CMD_SEC_SHIFT;

		memcpy(&tx_cmd->key[3], keyinfo->key, keyinfo->keylen);

		IWL_DEBUG_TX(priv, "Configuring packet for WEP encryption "
			     "with key %d\n", info->control.hw_key->hw_key_idx);
		break;

	default:
		IWL_ERR(priv, "Unknown encode cipher %x\n", keyinfo->cipher);
		break;
	}
}

/*
 * handle build REPLY_TX command notification.
 */
static void iwl3945_build_tx_cmd_basic(struct iwl_priv *priv,
				  struct iwl_device_cmd *cmd,
				  struct ieee80211_tx_info *info,
				  struct ieee80211_hdr *hdr, u8 std_id)
{
	struct iwl3945_tx_cmd *tx_cmd = (struct iwl3945_tx_cmd *)cmd->cmd.payload;
	__le32 tx_flags = tx_cmd->tx_flags;
	__le16 fc = hdr->frame_control;

	tx_cmd->stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
	if (!(info->flags & IEEE80211_TX_CTL_NO_ACK)) {
		tx_flags |= TX_CMD_FLG_ACK_MSK;
		if (ieee80211_is_mgmt(fc))
			tx_flags |= TX_CMD_FLG_SEQ_CTL_MSK;
		if (ieee80211_is_probe_resp(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;
	}

	tx_cmd->sta_id = std_id;
	if (ieee80211_has_morefrags(fc))
		tx_flags |= TX_CMD_FLG_MORE_FRAG_MSK;

	if (ieee80211_is_data_qos(fc)) {
		u8 *qc = ieee80211_get_qos_ctl(hdr);
		tx_cmd->tid_tspec = qc[0] & 0xf;
		tx_flags &= ~TX_CMD_FLG_SEQ_CTL_MSK;
	} else {
		tx_flags |= TX_CMD_FLG_SEQ_CTL_MSK;
	}

	priv->cfg->ops->utils->tx_cmd_protection(priv, info, fc, &tx_flags);

	tx_flags &= ~(TX_CMD_FLG_ANT_SEL_MSK);
	if (ieee80211_is_mgmt(fc)) {
		if (ieee80211_is_assoc_req(fc) || ieee80211_is_reassoc_req(fc))
			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;
}

/*
 * start REPLY_TX command process
 */
static int iwl3945_tx_skb(struct iwl_priv *priv, struct sk_buff *skb)
{
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
	struct iwl3945_tx_cmd *tx_cmd;
	struct iwl_tx_queue *txq = NULL;
	struct iwl_queue *q = NULL;
	struct iwl_device_cmd *out_cmd;
	struct iwl_cmd_meta *out_meta;
	dma_addr_t phys_addr;
	dma_addr_t txcmd_phys;
	int txq_id = skb_get_queue_mapping(skb);
	u16 len, idx, len_org, hdr_len; /* TODO: len_org is not used */
	u8 id;
	u8 unicast;
	u8 sta_id;
	u8 tid = 0;
	__le16 fc;
	u8 wait_write_ptr = 0;
	unsigned long flags;

	spin_lock_irqsave(&priv->lock, flags);
	if (iwl_is_rfkill(priv)) {
		IWL_DEBUG_DROP(priv, "Dropping - RF KILL\n");
		goto drop_unlock;
	}

	if ((ieee80211_get_tx_rate(priv->hw, info)->hw_value & 0xFF) == IWL_INVALID_RATE) {
		IWL_ERR(priv, "ERROR: No TX rate available.\n");
		goto drop_unlock;
	}

	unicast = !is_multicast_ether_addr(hdr->addr1);
	id = 0;

	fc = hdr->frame_control;

#ifdef CONFIG_IWLWIFI_DEBUG
	if (ieee80211_is_auth(fc))
		IWL_DEBUG_TX(priv, "Sending AUTH frame\n");
	else if (ieee80211_is_assoc_req(fc))
		IWL_DEBUG_TX(priv, "Sending ASSOC frame\n");
	else if (ieee80211_is_reassoc_req(fc))
		IWL_DEBUG_TX(priv, "Sending REASSOC frame\n");
#endif

	spin_unlock_irqrestore(&priv->lock, flags);

	hdr_len = ieee80211_hdrlen(fc);

	/* Find index into station table for destination station */
	sta_id = iwl_sta_id_or_broadcast(priv, info->control.sta);
	if (sta_id == IWL_INVALID_STATION) {
		IWL_DEBUG_DROP(priv, "Dropping - INVALID STATION: %pM\n",
			       hdr->addr1);
		goto drop;
	}

	IWL_DEBUG_RATE(priv, "station Id %d\n", sta_id);

	if (ieee80211_is_data_qos(fc)) {
		u8 *qc = ieee80211_get_qos_ctl(hdr);
		tid = qc[0] & IEEE80211_QOS_CTL_TID_MASK;
		if (unlikely(tid >= MAX_TID_COUNT))
			goto drop;
	}

	/* Descriptor for chosen Tx queue */
	txq = &priv->txq[txq_id];
	q = &txq->q;

	if ((iwl_queue_space(q) < q->high_mark))
		goto drop;

	spin_lock_irqsave(&priv->lock, flags);

	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 = skb;

	/* Init first empty entry in queue's array of Tx/cmd buffers */
	out_cmd = txq->cmd[idx];
	out_meta = &txq->meta[idx];
	tx_cmd = (struct iwl3945_tx_cmd *)out_cmd->cmd.payload;
	memset(&out_cmd->hdr, 0, sizeof(out_cmd->hdr));
	memset(tx_cmd, 0, sizeof(*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);


	if (info->control.hw_key)
		iwl3945_build_tx_cmd_hwcrypto(priv, info, out_cmd, skb, sta_id);

	/* TODO need this for burst mode later on */
	iwl3945_build_tx_cmd_basic(priv, out_cmd, info, hdr, sta_id);

	/* set is_hcca to 0; it probably will never be implemented */
	iwl3945_hw_build_tx_cmd_rate(priv, out_cmd, info, hdr, sta_id, 0);

	/* Total # bytes to be transmitted */
	len = (u16)skb->len;
	tx_cmd->len = cpu_to_le16(len);

	iwl_dbg_log_tx_data_frame(priv, len, hdr);
	iwl_update_stats(priv, true, fc, len);
	tx_cmd->tx_flags &= ~TX_CMD_FLG_ANT_A_MSK;
	tx_cmd->tx_flags &= ~TX_CMD_FLG_ANT_B_MSK;

	if (!ieee80211_has_morefrags(hdr->frame_control)) {
		txq->need_update = 1;
	} else {
		wait_write_ptr = 1;
		txq->need_update = 0;
	}

	IWL_DEBUG_TX(priv, "sequence nr = 0X%x\n",
		     le16_to_cpu(out_cmd->hdr.sequence));
	IWL_DEBUG_TX(priv, "tx_flags = 0X%x\n", le32_to_cpu(tx_cmd->tx_flags));
	iwl_print_hex_dump(priv, IWL_DL_TX, tx_cmd, sizeof(*tx_cmd));
	iwl_print_hex_dump(priv, IWL_DL_TX, (u8 *)tx_cmd->hdr,
			   ieee80211_hdrlen(fc));

	/*
	 * 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 iwl3945_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 = pci_map_single(priv->pci_dev, &out_cmd->hdr,
				    len, PCI_DMA_TODEVICE);
	/* we do not map meta data ... so we can safely access address to
	 * provide to unmap command*/
	dma_unmap_addr_set(out_meta, mapping, txcmd_phys);
	dma_unmap_len_set(out_meta, len, len);

	/* Add buffer containing Tx command and MAC(!) header to TFD's
	 * first entry */
	priv->cfg->ops->lib->txq_attach_buf_to_tfd(priv, txq,
						   txcmd_phys, len, 1, 0);


	/* 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);
		priv->cfg->ops->lib->txq_attach_buf_to_tfd(priv, txq,
							   phys_addr, len,
							   0, U32_PAD(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);
	iwl_txq_update_write_ptr(priv, txq);
	spin_unlock_irqrestore(&priv->lock, flags);

	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);
		}

		iwl_stop_queue(priv, skb_get_queue_mapping(skb));
	}

	return 0;

drop_unlock:
	spin_unlock_irqrestore(&priv->lock, flags);
drop:
	return -1;
}

static int iwl3945_get_measurement(struct iwl_priv *priv,
			       struct ieee80211_measurement_params *params,
			       u8 type)
{
	struct iwl_spectrum_cmd spectrum;
	struct iwl_rx_packet *pkt;
	struct iwl_host_cmd cmd = {
		.id = REPLY_SPECTRUM_MEASUREMENT_CMD,
		.data = (void *)&spectrum,
		.flags = CMD_WANT_SKB,
	};
	u32 add_time = le64_to_cpu(params->start_time);
	int rc;
	int spectrum_resp_status;
	int duration = le16_to_cpu(params->duration);

	if (iwl_is_associated(priv))
		add_time = iwl_usecs_to_beacons(priv,
			le64_to_cpu(params->start_time) - priv->_3945.last_tsf,
			le16_to_cpu(priv->rxon_timing.beacon_interval));

	memset(&spectrum, 0, sizeof(spectrum));

	spectrum.channel_count = cpu_to_le16(1);
	spectrum.flags =
	    RXON_FLG_TSF2HOST_MSK | RXON_FLG_ANT_A_MSK | RXON_FLG_DIS_DIV_MSK;
	spectrum.filter_flags = MEASUREMENT_FILTER_FLAG;
	cmd.len = sizeof(spectrum);
	spectrum.len = cpu_to_le16(cmd.len - sizeof(spectrum.len));

	if (iwl_is_associated(priv))
		spectrum.start_time =
			iwl_add_beacon_time(priv,
				priv->_3945.last_beacon_time, add_time,
				le16_to_cpu(priv->rxon_timing.beacon_interval));
	else
		spectrum.start_time = 0;

	spectrum.channels[0].duration = cpu_to_le32(duration * TIME_UNIT);
	spectrum.channels[0].channel = params->channel;
	spectrum.channels[0].type = type;
	if (priv->active_rxon.flags & RXON_FLG_BAND_24G_MSK)
		spectrum.flags |= RXON_FLG_BAND_24G_MSK |
		    RXON_FLG_AUTO_DETECT_MSK | RXON_FLG_TGG_PROTECT_MSK;

	rc = iwl_send_cmd_sync(priv, &cmd);
	if (rc)
		return rc;

	pkt = (struct iwl_rx_packet *)cmd.reply_page;
	if (pkt->hdr.flags & IWL_CMD_FAILED_MSK) {
		IWL_ERR(priv, "Bad return from REPLY_RX_ON_ASSOC command\n");
		rc = -EIO;
	}

	spectrum_resp_status = le16_to_cpu(pkt->u.spectrum.status);
	switch (spectrum_resp_status) {
	case 0:		/* Command will be handled */
		if (pkt->u.spectrum.id != 0xff) {
			IWL_DEBUG_INFO(priv, "Replaced existing measurement: %d\n",
						pkt->u.spectrum.id);
			priv->measurement_status &= ~MEASUREMENT_READY;
		}
		priv->measurement_status |= MEASUREMENT_ACTIVE;
		rc = 0;
		break;

	case 1:		/* Command will not be handled */
		rc = -EAGAIN;
		break;
	}

	iwl_free_pages(priv, cmd.reply_page);

	return rc;
}

static void iwl3945_rx_reply_alive(struct iwl_priv *priv,
			       struct iwl_rx_mem_buffer *rxb)
{
	struct iwl_rx_packet *pkt = rxb_addr(rxb);
	struct iwl_alive_resp *palive;
	struct delayed_work *pwork;

	palive = &pkt->u.alive_frame;

	IWL_DEBUG_INFO(priv, "Alive ucode status 0x%08X revision "
		       "0x%01X 0x%01X\n",
		       palive->is_valid, palive->ver_type,
		       palive->ver_subtype);

	if (palive->ver_subtype == INITIALIZE_SUBTYPE) {
		IWL_DEBUG_INFO(priv, "Initialization Alive received.\n");
		memcpy(&priv->card_alive_init, &pkt->u.alive_frame,
		       sizeof(struct iwl_alive_resp));
		pwork = &priv->init_alive_start;
	} else {
		IWL_DEBUG_INFO(priv, "Runtime Alive received.\n");
		memcpy(&priv->card_alive, &pkt->u.alive_frame,
		       sizeof(struct iwl_alive_resp));
		pwork = &priv->alive_start;
		iwl3945_disable_events(priv);
	}

	/* We delay the ALIVE response by 5ms to
	 * give the HW RF Kill time to activate... */
	if (palive->is_valid == UCODE_VALID_OK)
		queue_delayed_work(priv->workqueue, pwork,
				   msecs_to_jiffies(5));
	else
		IWL_WARN(priv, "uCode did not respond OK.\n");
}

static void iwl3945_rx_reply_add_sta(struct iwl_priv *priv,
				 struct iwl_rx_mem_buffer *rxb)
{
#ifdef CONFIG_IWLWIFI_DEBUG
	struct iwl_rx_packet *pkt = rxb_addr(rxb);
#endif

	IWL_DEBUG_RX(priv, "Received REPLY_ADD_STA: 0x%02X\n", pkt->u.status);
}

static void iwl3945_bg_beacon_update(struct work_struct *work)
{
	struct iwl_priv *priv =
		container_of(work, struct iwl_priv, beacon_update);
	struct sk_buff *beacon;

	/* Pull updated AP beacon from mac80211. will fail if not in AP mode */
	beacon = ieee80211_beacon_get(priv->hw, priv->vif);

	if (!beacon) {
		IWL_ERR(priv, "update beacon failed\n");
		return;
	}

	mutex_lock(&priv->mutex);
	/* new beacon skb is allocated every time; dispose previous.*/
	if (priv->ibss_beacon)
		dev_kfree_skb(priv->ibss_beacon);

	priv->ibss_beacon = beacon;
	mutex_unlock(&priv->mutex);

	iwl3945_send_beacon_cmd(priv);
}

static void iwl3945_rx_beacon_notif(struct iwl_priv *priv,
				struct iwl_rx_mem_buffer *rxb)
{
	struct iwl_rx_packet *pkt = rxb_addr(rxb);
	struct iwl3945_beacon_notif *beacon = &(pkt->u.beacon_status);
#ifdef CONFIG_IWLWIFI_DEBUG
	u8 rate = beacon->beacon_notify_hdr.rate;

	IWL_DEBUG_RX(priv, "beacon status %x retries %d iss %d "
		"tsf %d %d rate %d\n",
		le32_to_cpu(beacon->beacon_notify_hdr.status) & TX_STATUS_MSK,
		beacon->beacon_notify_hdr.failure_frame,
		le32_to_cpu(beacon->ibss_mgr_status),
		le32_to_cpu(beacon->high_tsf),
		le32_to_cpu(beacon->low_tsf), rate);
#endif

	priv->ibss_manager = le32_to_cpu(beacon->ibss_mgr_status);

	if ((priv->iw_mode == NL80211_IFTYPE_AP) &&
	    (!test_bit(STATUS_EXIT_PENDING, &priv->status)))
		queue_work(priv->workqueue, &priv->beacon_update);
}

/* Handle notification from uCode that card's power state is changing
 * due to software, hardware, or critical temperature RFKILL */
static void iwl3945_rx_card_state_notif(struct iwl_priv *priv,
				    struct iwl_rx_mem_buffer *rxb)
{
	struct iwl_rx_packet *pkt = rxb_addr(rxb);
	u32 flags = le32_to_cpu(pkt->u.card_state_notif.flags);
	unsigned long status = priv->status;

	IWL_WARN(priv, "Card state received: HW:%s SW:%s\n",
			  (flags & HW_CARD_DISABLED) ? "Kill" : "On",
			  (flags & SW_CARD_DISABLED) ? "Kill" : "On");

	iwl_write32(priv, CSR_UCODE_DRV_GP1_SET,
		    CSR_UCODE_DRV_GP1_BIT_CMD_BLOCKED);

	if (flags & HW_CARD_DISABLED)
		set_bit(STATUS_RF_KILL_HW, &priv->status);
	else
		clear_bit(STATUS_RF_KILL_HW, &priv->status);


	iwl_scan_cancel(priv);

	if ((test_bit(STATUS_RF_KILL_HW, &status) !=
	     test_bit(STATUS_RF_KILL_HW, &priv->status)))
		wiphy_rfkill_set_hw_state(priv->hw->wiphy,
				test_bit(STATUS_RF_KILL_HW, &priv->status));
	else
		wake_up_interruptible(&priv->wait_command_queue);
}

/**
 * iwl3945_setup_rx_handlers - Initialize Rx handler callbacks
 *
 * Setup the RX handlers for each of the reply types sent from the uCode
 * to the host.
 *
 * This function chains into the hardware specific files for them to setup
 * any hardware specific handlers as well.
 */
static void iwl3945_setup_rx_handlers(struct iwl_priv *priv)
{
	priv->rx_handlers[REPLY_ALIVE] = iwl3945_rx_reply_alive;
	priv->rx_handlers[REPLY_ADD_STA] = iwl3945_rx_reply_add_sta;
	priv->rx_handlers[REPLY_ERROR] = iwl_rx_reply_error;
	priv->rx_handlers[CHANNEL_SWITCH_NOTIFICATION] = iwl_rx_csa;
	priv->rx_handlers[SPECTRUM_MEASURE_NOTIFICATION] =
			iwl_rx_spectrum_measure_notif;
	priv->rx_handlers[PM_SLEEP_NOTIFICATION] = iwl_rx_pm_sleep_notif;
	priv->rx_handlers[PM_DEBUG_STATISTIC_NOTIFIC] =
	    iwl_rx_pm_debug_statistics_notif;
	priv->rx_handlers[BEACON_NOTIFICATION] = iwl3945_rx_beacon_notif;

	/*
	 * The same handler is used for both the REPLY to a discrete
	 * statistics request from the host as well as for the periodic
	 * statistics notifications (after received beacons) from the uCode.
	 */
	priv->rx_handlers[REPLY_STATISTICS_CMD] = iwl3945_reply_statistics;
	priv->rx_handlers[STATISTICS_NOTIFICATION] = iwl3945_hw_rx_statistics;

	iwl_setup_rx_scan_handlers(priv);
	priv->rx_handlers[CARD_STATE_NOTIFICATION] = iwl3945_rx_card_state_notif;

	/* Set up hardware specific Rx handlers */
	iwl3945_hw_rx_handler_setup(priv);
}

/************************** RX-FUNCTIONS ****************************/
/*
 * Rx theory of operation
 *
 * The host allocates 32 DMA target addresses and passes the host address
 * to the firmware at register IWL_RFDS_TABLE_LOWER + N * RFD_SIZE where N is
 * 0 to 31
 *
 * Rx Queue Indexes
 * The host/firmware share two index registers for managing the Rx buffers.
 *
 * The READ index maps to the first position that the firmware may be writing
 * to -- the driver can read up to (but not including) this position and get
 * good data.
 * The READ index is managed by the firmware once the card is enabled.
 *
 * The WRITE index maps to the last position the driver has read from -- the
 * position preceding WRITE is the last slot the firmware can place a packet.
 *
 * The queue is empty (no good data) if WRITE = READ - 1, and is full if
 * WRITE = READ.
 *
 * During initialization, the host sets up the READ queue position to the first
 * INDEX position, and WRITE to the last (READ - 1 wrapped)
 *
 * When the firmware places a packet in a buffer, it will advance the READ index
 * and fire the RX interrupt.  The driver can then query the READ index and
 * process as many packets as possible, moving the WRITE index forward as it
 * resets the Rx queue buffers with new memory.
 *
 * The management in the driver is as follows:
 * + A list of pre-allocated SKBs is stored in iwl->rxq->rx_free.  When
 *   iwl->rxq->free_count drops to or below RX_LOW_WATERMARK, work is scheduled
 *   to replenish the iwl->rxq->rx_free.
 * + In iwl3945_rx_replenish (scheduled) if 'processed' != 'read' then the
 *   iwl->rxq is replenished and the READ INDEX is updated (updating the
 *   'processed' and 'read' driver indexes as well)
 * + A received packet is processed and handed to the kernel network stack,
 *   detached from the iwl->rxq.  The driver 'processed' index is updated.
 * + The Host/Firmware iwl->rxq is replenished at tasklet time from the rx_free
 *   list. If there are no allocated buffers in iwl->rxq->rx_free, the READ
 *   INDEX is not incremented and iwl->status(RX_STALLED) is set.  If there
 *   were enough free buffers and RX_STALLED is set it is cleared.
 *
 *
 * Driver sequence:
 *
 * iwl3945_rx_replenish()     Replenishes rx_free list from rx_used, and calls
 *                            iwl3945_rx_queue_restock
 * iwl3945_rx_queue_restock() Moves available buffers from rx_free into Rx
 *                            queue, updates firmware pointers, and updates
 *                            the WRITE index.  If insufficient rx_free buffers
 *                            are available, schedules iwl3945_rx_replenish
 *
 * -- enable interrupts --
 * ISR - iwl3945_rx()         Detach iwl_rx_mem_buffers from pool up to the
 *                            READ INDEX, detaching the SKB from the pool.
 *                            Moves the packet buffer from queue to rx_used.
 *                            Calls iwl3945_rx_queue_restock to refill any empty
 *                            slots.
 * ...
 *
 */

/**
 * iwl3945_dma_addr2rbd_ptr - convert a DMA address to a uCode read buffer ptr
 */
static inline __le32 iwl3945_dma_addr2rbd_ptr(struct iwl_priv *priv,
					  dma_addr_t dma_addr)
{
	return cpu_to_le32((u32)dma_addr);
}

/**
 * iwl3945_rx_queue_restock - refill RX queue from pre-allocated pool
 *
 * If there are slots in the RX queue that need to be restocked,
 * and we have free pre-allocated buffers, fill the ranks as much
 * as we can, pulling from rx_free.
 *
 * This moves the 'write' index forward to catch up with 'processed', and
 * also updates the memory address in the firmware to reference the new
 * target buffer.
 */
static void iwl3945_rx_queue_restock(struct iwl_priv *priv)
{
	struct iwl_rx_queue *rxq = &priv->rxq;
	struct list_head *element;
	struct iwl_rx_mem_buffer *rxb;