iwlwifi: split the drivers for agn and legacy devices 3945/4965

Intel WiFi devices 3945 and 4965 now have their own driver in the folder

	drivers/net/wireless/iwlegacy

Add support to build these drivers independently of the driver for
AGN devices. Selecting the 3945 builds iwl3945.ko and iwl_legacy.ko,
and selecting the 4965 builds iwl4965.ko and iwl_legacy.ko. iwl-legacy.ko
contains code shared between both devices.

The 3945 is an ABG/BG device, with no support for 802.11n. The 4965 is a 2x3
ABGN device.

Signed-off-by: Meenakshi Venkataraman <meenakshi.venkataraman@intel.com>
Acked-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>

1 files changed, 1260 insertions, 0 deletions

diff --git a/drivers/net/wireless/iwlegacy/iwl-4965-lib.c b/drivers/net/wireless/iwlegacy/iwl-4965-lib.c
new file mode 100644
index 0000000..c1a2494
--- /dev/null
+++ b/drivers/net/wireless/iwlegacy/iwl-4965-lib.c
@@ -0,0 +1,1260 @@
+/******************************************************************************
+ *
+ * GPL LICENSE SUMMARY
+ *
+ * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
+ *
+ * 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.GPL.
+ *
+ * Contact Information:
+ *  Intel Linux Wireless <ilw@linux.intel.com>
+ * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
+ *
+ *****************************************************************************/
+#include <linux/etherdevice.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+
+#include "iwl-dev.h"
+#include "iwl-core.h"
+#include "iwl-io.h"
+#include "iwl-helpers.h"
+#include "iwl-4965-hw.h"
+#include "iwl-4965.h"
+#include "iwl-sta.h"
+
+void iwl4965_check_abort_status(struct iwl_priv *priv,
+			    u8 frame_count, u32 status)
+{
+	if (frame_count == 1 && status == TX_STATUS_FAIL_RFKILL_FLUSH) {
+		IWL_ERR(priv, "Tx flush command to flush out all frames\n");
+		if (!test_bit(STATUS_EXIT_PENDING, &priv->status))
+			queue_work(priv->workqueue, &priv->tx_flush);
+	}
+}
+
+/*
+ * EEPROM
+ */
+struct iwl_mod_params iwl4965_mod_params = {
+	.amsdu_size_8K = 1,
+	.restart_fw = 1,
+	/* the rest are 0 by default */
+};
+
+void iwl4965_rx_queue_reset(struct iwl_priv *priv, struct iwl_rx_queue *rxq)
+{
+	unsigned long flags;
+	int i;
+	spin_lock_irqsave(&rxq->lock, flags);
+	INIT_LIST_HEAD(&rxq->rx_free);
+	INIT_LIST_HEAD(&rxq->rx_used);
+	/* Fill the rx_used queue with _all_ of the Rx buffers */
+	for (i = 0; i < RX_FREE_BUFFERS + RX_QUEUE_SIZE; i++) {
+		/* In the reset function, these buffers may have been allocated
+		 * to an SKB, so we need to unmap and free potential storage */
+		if (rxq->pool[i].page != NULL) {
+			pci_unmap_page(priv->pci_dev, rxq->pool[i].page_dma,
+				PAGE_SIZE << priv->hw_params.rx_page_order,
+				PCI_DMA_FROMDEVICE);
+			__iwl_legacy_free_pages(priv, rxq->pool[i].page);
+			rxq->pool[i].page = NULL;
+		}
+		list_add_tail(&rxq->pool[i].list, &rxq->rx_used);
+	}
+
+	for (i = 0; i < RX_QUEUE_SIZE; i++)
+		rxq->queue[i] = NULL;
+
+	/* Set us so that we have processed and used all buffers, but have
+	 * not restocked the Rx queue with fresh buffers */
+	rxq->read = rxq->write = 0;
+	rxq->write_actual = 0;
+	rxq->free_count = 0;
+	spin_unlock_irqrestore(&rxq->lock, flags);
+}
+
+int iwl4965_rx_init(struct iwl_priv *priv, struct iwl_rx_queue *rxq)
+{
+	u32 rb_size;
+	const u32 rfdnlog = RX_QUEUE_SIZE_LOG; /* 256 RBDs */
+	u32 rb_timeout = 0;
+
+	if (priv->cfg->mod_params->amsdu_size_8K)
+		rb_size = FH_RCSR_RX_CONFIG_REG_VAL_RB_SIZE_8K;
+	else
+		rb_size = FH_RCSR_RX_CONFIG_REG_VAL_RB_SIZE_4K;
+
+	/* Stop Rx DMA */
+	iwl_legacy_write_direct32(priv, FH_MEM_RCSR_CHNL0_CONFIG_REG, 0);
+
+	/* Reset driver's Rx queue write index */
+	iwl_legacy_write_direct32(priv, FH_RSCSR_CHNL0_RBDCB_WPTR_REG, 0);
+
+	/* Tell device where to find RBD circular buffer in DRAM */
+	iwl_legacy_write_direct32(priv, FH_RSCSR_CHNL0_RBDCB_BASE_REG,
+			   (u32)(rxq->bd_dma >> 8));
+
+	/* Tell device where in DRAM to update its Rx status */
+	iwl_legacy_write_direct32(priv, FH_RSCSR_CHNL0_STTS_WPTR_REG,
+			   rxq->rb_stts_dma >> 4);
+
+	/* Enable Rx DMA
+	 * Direct rx interrupts to hosts
+	 * Rx buffer size 4 or 8k
+	 * RB timeout 0x10
+	 * 256 RBDs
+	 */
+	iwl_legacy_write_direct32(priv, FH_MEM_RCSR_CHNL0_CONFIG_REG,
+			   FH_RCSR_RX_CONFIG_CHNL_EN_ENABLE_VAL |
+			   FH_RCSR_CHNL0_RX_CONFIG_IRQ_DEST_INT_HOST_VAL |
+			   FH_RCSR_CHNL0_RX_CONFIG_SINGLE_FRAME_MSK |
+			   rb_size|
+			   (rb_timeout << FH_RCSR_RX_CONFIG_REG_IRQ_RBTH_POS)|
+			   (rfdnlog << FH_RCSR_RX_CONFIG_RBDCB_SIZE_POS));
+
+	/* Set interrupt coalescing timer to default (2048 usecs) */
+	iwl_write8(priv, CSR_INT_COALESCING, IWL_HOST_INT_TIMEOUT_DEF);
+
+	return 0;
+}
+
+static void iwl4965_set_pwr_vmain(struct iwl_priv *priv)
+{
+/*
+ * (for documentation purposes)
+ * to set power to V_AUX, do:
+
+		if (pci_pme_capable(priv->pci_dev, PCI_D3cold))
+			iwl_legacy_set_bits_mask_prph(priv, APMG_PS_CTRL_REG,
+					       APMG_PS_CTRL_VAL_PWR_SRC_VAUX,
+					       ~APMG_PS_CTRL_MSK_PWR_SRC);
+ */
+
+	iwl_legacy_set_bits_mask_prph(priv, APMG_PS_CTRL_REG,
+			       APMG_PS_CTRL_VAL_PWR_SRC_VMAIN,
+			       ~APMG_PS_CTRL_MSK_PWR_SRC);
+}
+
+int iwl4965_hw_nic_init(struct iwl_priv *priv)
+{
+	unsigned long flags;
+	struct iwl_rx_queue *rxq = &priv->rxq;
+	int ret;
+
+	/* nic_init */
+	spin_lock_irqsave(&priv->lock, flags);
+	priv->cfg->ops->lib->apm_ops.init(priv);
+
+	/* Set interrupt coalescing calibration timer to default (512 usecs) */
+	iwl_write8(priv, CSR_INT_COALESCING, IWL_HOST_INT_CALIB_TIMEOUT_DEF);
+
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	iwl4965_set_pwr_vmain(priv);
+
+	priv->cfg->ops->lib->apm_ops.config(priv);
+
+	/* Allocate the RX queue, or reset if it is already allocated */
+	if (!rxq->bd) {
+		ret = iwl_legacy_rx_queue_alloc(priv);
+		if (ret) {
+			IWL_ERR(priv, "Unable to initialize Rx queue\n");
+			return -ENOMEM;
+		}
+	} else
+		iwl4965_rx_queue_reset(priv, rxq);
+
+	iwl4965_rx_replenish(priv);
+
+	iwl4965_rx_init(priv, rxq);
+
+	spin_lock_irqsave(&priv->lock, flags);
+
+	rxq->need_update = 1;
+	iwl_legacy_rx_queue_update_write_ptr(priv, rxq);
+
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	/* Allocate or reset and init all Tx and Command queues */
+	if (!priv->txq) {
+		ret = iwl4965_txq_ctx_alloc(priv);
+		if (ret)
+			return ret;
+	} else
+		iwl4965_txq_ctx_reset(priv);
+
+	set_bit(STATUS_INIT, &priv->status);
+
+	return 0;
+}
+
+/**
+ * iwl4965_dma_addr2rbd_ptr - convert a DMA address to a uCode read buffer ptr
+ */
+static inline __le32 iwl4965_dma_addr2rbd_ptr(struct iwl_priv *priv,
+					  dma_addr_t dma_addr)
+{
+	return cpu_to_le32((u32)(dma_addr >> 8));
+}
+
+/**
+ * iwl4965_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.
+ */
+void iwl4965_rx_queue_restock(struct iwl_priv *priv)
+{
+	struct iwl_rx_queue *rxq = &priv->rxq;
+	struct list_head *element;
+	struct iwl_rx_mem_buffer *rxb;
+	unsigned long flags;
+
+	spin_lock_irqsave(&rxq->lock, flags);
+	while ((iwl_legacy_rx_queue_space(rxq) > 0) && (rxq->free_count)) {
+		/* The overwritten rxb must be a used one */
+		rxb = rxq->queue[rxq->write];
+		BUG_ON(rxb && rxb->page);
+
+		/* Get next free Rx buffer, remove from free list */
+		element = rxq->rx_free.next;
+		rxb = list_entry(element, struct iwl_rx_mem_buffer, list);
+		list_del(element);
+
+		/* Point to Rx buffer via next RBD in circular buffer */
+		rxq->bd[rxq->write] = iwl4965_dma_addr2rbd_ptr(priv,
+							      rxb->page_dma);
+		rxq->queue[rxq->write] = rxb;
+		rxq->write = (rxq->write + 1) & RX_QUEUE_MASK;
+		rxq->free_count--;
+	}
+	spin_unlock_irqrestore(&rxq->lock, flags);
+	/* If the pre-allocated buffer pool is dropping low, schedule to
+	 * refill it */
+	if (rxq->free_count <= RX_LOW_WATERMARK)
+		queue_work(priv->workqueue, &priv->rx_replenish);
+
+
+	/* If we've added more space for the firmware to place data, tell it.
+	 * Increment device's write pointer in multiples of 8. */
+	if (rxq->write_actual != (rxq->write & ~0x7)) {
+		spin_lock_irqsave(&rxq->lock, flags);
+		rxq->need_update = 1;
+		spin_unlock_irqrestore(&rxq->lock, flags);
+		iwl_legacy_rx_queue_update_write_ptr(priv, rxq);
+	}
+}
+
+/**
+ * iwl4965_rx_replenish - Move all used packet from rx_used to rx_free
+ *
+ * When moving to rx_free an SKB is allocated for the slot.
+ *
+ * Also restock the Rx queue via iwl_rx_queue_restock.
+ * This is called as a scheduled work item (except for during initialization)
+ */
+static void iwl4965_rx_allocate(struct iwl_priv *priv, gfp_t priority)
+{
+	struct iwl_rx_queue *rxq = &priv->rxq;
+	struct list_head *element;
+	struct iwl_rx_mem_buffer *rxb;
+	struct page *page;
+	unsigned long flags;
+	gfp_t gfp_mask = priority;
+
+	while (1) {
+		spin_lock_irqsave(&rxq->lock, flags);
+		if (list_empty(&rxq->rx_used)) {
+			spin_unlock_irqrestore(&rxq->lock, flags);
+			return;
+		}
+		spin_unlock_irqrestore(&rxq->lock, flags);
+
+		if (rxq->free_count > RX_LOW_WATERMARK)
+			gfp_mask |= __GFP_NOWARN;
+
+		if (priv->hw_params.rx_page_order > 0)
+			gfp_mask |= __GFP_COMP;
+
+		/* Alloc a new receive buffer */
+		page = alloc_pages(gfp_mask, priv->hw_params.rx_page_order);
+		if (!page) {
+			if (net_ratelimit())
+				IWL_DEBUG_INFO(priv, "alloc_pages failed, "
+					       "order: %d\n",
+					       priv->hw_params.rx_page_order);
+
+			if ((rxq->free_count <= RX_LOW_WATERMARK) &&
+			    net_ratelimit())
+				IWL_CRIT(priv,
+					"Failed to alloc_pages with %s. "
+					"Only %u free buffers remaining.\n",
+					 priority == GFP_ATOMIC ?
+						 "GFP_ATOMIC" : "GFP_KERNEL",
+					 rxq->free_count);
+			/* We don't reschedule replenish work here -- we will
+			 * call the restock method and if it still needs
+			 * more buffers it will schedule replenish */
+			return;
+		}
+
+		spin_lock_irqsave(&rxq->lock, flags);
+
+		if (list_empty(&rxq->rx_used)) {
+			spin_unlock_irqrestore(&rxq->lock, flags);
+			__free_pages(page, priv->hw_params.rx_page_order);
+			return;
+		}
+		element = rxq->rx_used.next;
+		rxb = list_entry(element, struct iwl_rx_mem_buffer, list);
+		list_del(element);
+
+		spin_unlock_irqrestore(&rxq->lock, flags);
+
+		BUG_ON(rxb->page);
+		rxb->page = page;
+		/* Get physical address of the RB */
+		rxb->page_dma = pci_map_page(priv->pci_dev, page, 0,
+				PAGE_SIZE << priv->hw_params.rx_page_order,
+				PCI_DMA_FROMDEVICE);
+		/* dma address must be no more than 36 bits */
+		BUG_ON(rxb->page_dma & ~DMA_BIT_MASK(36));
+		/* and also 256 byte aligned! */
+		BUG_ON(rxb->page_dma & DMA_BIT_MASK(8));
+
+		spin_lock_irqsave(&rxq->lock, flags);
+
+		list_add_tail(&rxb->list, &rxq->rx_free);
+		rxq->free_count++;
+		priv->alloc_rxb_page++;
+
+		spin_unlock_irqrestore(&rxq->lock, flags);
+	}
+}
+
+void iwl4965_rx_replenish(struct iwl_priv *priv)
+{
+	unsigned long flags;
+
+	iwl4965_rx_allocate(priv, GFP_KERNEL);
+
+	spin_lock_irqsave(&priv->lock, flags);
+	iwl4965_rx_queue_restock(priv);
+	spin_unlock_irqrestore(&priv->lock, flags);
+}
+
+void iwl4965_rx_replenish_now(struct iwl_priv *priv)
+{
+	iwl4965_rx_allocate(priv, GFP_ATOMIC);
+
+	iwl4965_rx_queue_restock(priv);
+}
+
+/* Assumes that the skb field of the buffers in 'pool' is kept accurate.
+ * If an SKB has been detached, the POOL needs to have its SKB set to NULL
+ * This free routine walks the list of POOL entries and if SKB is set to
+ * non NULL it is unmapped and freed
+ */
+void iwl4965_rx_queue_free(struct iwl_priv *priv, struct iwl_rx_queue *rxq)
+{
+	int i;
+	for (i = 0; i < RX_QUEUE_SIZE + RX_FREE_BUFFERS; i++) {
+		if (rxq->pool[i].page != NULL) {
+			pci_unmap_page(priv->pci_dev, rxq->pool[i].page_dma,
+				PAGE_SIZE << priv->hw_params.rx_page_order,
+				PCI_DMA_FROMDEVICE);
+			__iwl_legacy_free_pages(priv, rxq->pool[i].page);
+			rxq->pool[i].page = NULL;
+		}
+	}
+
+	dma_free_coherent(&priv->pci_dev->dev, 4 * RX_QUEUE_SIZE, rxq->bd,
+			  rxq->bd_dma);
+	dma_free_coherent(&priv->pci_dev->dev, sizeof(struct iwl_rb_status),
+			  rxq->rb_stts, rxq->rb_stts_dma);
+	rxq->bd = NULL;
+	rxq->rb_stts  = NULL;
+}
+
+int iwl4965_rxq_stop(struct iwl_priv *priv)
+{
+
+	/* stop Rx DMA */
+	iwl_legacy_write_direct32(priv, FH_MEM_RCSR_CHNL0_CONFIG_REG, 0);
+	iwl_poll_direct_bit(priv, FH_MEM_RSSR_RX_STATUS_REG,
+			    FH_RSSR_CHNL0_RX_STATUS_CHNL_IDLE, 1000);
+
+	return 0;
+}
+
+int iwl4965_hwrate_to_mac80211_idx(u32 rate_n_flags, enum ieee80211_band band)
+{
+	int idx = 0;
+	int band_offset = 0;
+
+	/* HT rate format: mac80211 wants an MCS number, which is just LSB */
+	if (rate_n_flags & RATE_MCS_HT_MSK) {
+		idx = (rate_n_flags & 0xff);
+		return idx;
+	/* Legacy rate format, search for match in table */
+	} else {
+		if (band == IEEE80211_BAND_5GHZ)
+			band_offset = IWL_FIRST_OFDM_RATE;
+		for (idx = band_offset; idx < IWL_RATE_COUNT_LEGACY; idx++)
+			if (iwl_rates[idx].plcp == (rate_n_flags & 0xFF))
+				return idx - band_offset;
+	}
+
+	return -1;
+}
+
+static int iwl4965_calc_rssi(struct iwl_priv *priv,
+			     struct iwl_rx_phy_res *rx_resp)
+{
+	/* data from PHY/DSP regarding signal strength, etc.,
+	 *   contents are always there, not configurable by host.  */
+	struct iwl4965_rx_non_cfg_phy *ncphy =
+	    (struct iwl4965_rx_non_cfg_phy *)rx_resp->non_cfg_phy_buf;
+	u32 agc = (le16_to_cpu(ncphy->agc_info) & IWL49_AGC_DB_MASK)
+			>> IWL49_AGC_DB_POS;
+
+	u32 valid_antennae =
+	    (le16_to_cpu(rx_resp->phy_flags) & IWL49_RX_PHY_FLAGS_ANTENNAE_MASK)
+			>> IWL49_RX_PHY_FLAGS_ANTENNAE_OFFSET;
+	u8 max_rssi = 0;
+	u32 i;
+
+	/* Find max rssi among 3 possible receivers.
+	 * These values are measured by the digital signal processor (DSP).
+	 * They should stay fairly constant even as the signal strength varies,
+	 *   if the radio's automatic gain control (AGC) is working right.
+	 * AGC value (see below) will provide the "interesting" info. */
+	for (i = 0; i < 3; i++)
+		if (valid_antennae & (1 << i))
+			max_rssi = max(ncphy->rssi_info[i << 1], max_rssi);
+
+	IWL_DEBUG_STATS(priv, "Rssi In A %d B %d C %d Max %d AGC dB %d\n",
+		ncphy->rssi_info[0], ncphy->rssi_info[2], ncphy->rssi_info[4],
+		max_rssi, agc);
+
+	/* dBm = max_rssi dB - agc dB - constant.
+	 * Higher AGC (higher radio gain) means lower signal. */
+	return max_rssi - agc - IWL4965_RSSI_OFFSET;
+}
+
+
+static u32 iwl4965_translate_rx_status(struct iwl_priv *priv, u32 decrypt_in)
+{
+	u32 decrypt_out = 0;
+
+	if ((decrypt_in & RX_RES_STATUS_STATION_FOUND) ==
+					RX_RES_STATUS_STATION_FOUND)
+		decrypt_out |= (RX_RES_STATUS_STATION_FOUND |
+				RX_RES_STATUS_NO_STATION_INFO_MISMATCH);
+
+	decrypt_out |= (decrypt_in & RX_RES_STATUS_SEC_TYPE_MSK);
+
+	/* packet was not encrypted */
+	if ((decrypt_in & RX_RES_STATUS_SEC_TYPE_MSK) ==
+					RX_RES_STATUS_SEC_TYPE_NONE)
+		return decrypt_out;
+
+	/* packet was encrypted with unknown alg */
+	if ((decrypt_in & RX_RES_STATUS_SEC_TYPE_MSK) ==
+					RX_RES_STATUS_SEC_TYPE_ERR)
+		return decrypt_out;
+
+	/* decryption was not done in HW */
+	if ((decrypt_in & RX_MPDU_RES_STATUS_DEC_DONE_MSK) !=
+					RX_MPDU_RES_STATUS_DEC_DONE_MSK)
+		return decrypt_out;
+
+	switch (decrypt_in & RX_RES_STATUS_SEC_TYPE_MSK) {
+
+	case RX_RES_STATUS_SEC_TYPE_CCMP:
+		/* alg is CCM: check MIC only */
+		if (!(decrypt_in & RX_MPDU_RES_STATUS_MIC_OK))
+			/* Bad MIC */
+			decrypt_out |= RX_RES_STATUS_BAD_ICV_MIC;
+		else
+			decrypt_out |= RX_RES_STATUS_DECRYPT_OK;
+
+		break;
+
+	case RX_RES_STATUS_SEC_TYPE_TKIP:
+		if (!(decrypt_in & RX_MPDU_RES_STATUS_TTAK_OK)) {
+			/* Bad TTAK */
+			decrypt_out |= RX_RES_STATUS_BAD_KEY_TTAK;
+			break;
+		}
+		/* fall through if TTAK OK */
+	default:
+		if (!(decrypt_in & RX_MPDU_RES_STATUS_ICV_OK))
+			decrypt_out |= RX_RES_STATUS_BAD_ICV_MIC;
+		else
+			decrypt_out |= RX_RES_STATUS_DECRYPT_OK;
+		break;
+	}
+
+	IWL_DEBUG_RX(priv, "decrypt_in:0x%x  decrypt_out = 0x%x\n",
+					decrypt_in, decrypt_out);
+
+	return decrypt_out;
+}
+
+static void iwl4965_pass_packet_to_mac80211(struct iwl_priv *priv,
+					struct ieee80211_hdr *hdr,
+					u16 len,
+					u32 ampdu_status,
+					struct iwl_rx_mem_buffer *rxb,
+					struct ieee80211_rx_status *stats)
+{
+	struct sk_buff *skb;
+	__le16 fc = hdr->frame_control;
+
+	/* We only process data packets if the interface is open */
+	if (unlikely(!priv->is_open)) {
+		IWL_DEBUG_DROP_LIMIT(priv,
+		    "Dropping packet while interface is not open.\n");
+		return;
+	}
+
+	/* In case of HW accelerated crypto and bad decryption, drop */
+	if (!priv->cfg->mod_params->sw_crypto &&
+	    iwl_legacy_set_decrypted_flag(priv, hdr, ampdu_status, stats))
+		return;
+
+	skb = dev_alloc_skb(128);
+	if (!skb) {
+		IWL_ERR(priv, "dev_alloc_skb failed\n");
+		return;
+	}
+
+	skb_add_rx_frag(skb, 0, rxb->page, (void *)hdr - rxb_addr(rxb), len);
+
+	iwl_legacy_update_stats(priv, false, fc, len);
+	memcpy(IEEE80211_SKB_RXCB(skb), stats, sizeof(*stats));
+
+	ieee80211_rx(priv->hw, skb);
+	priv->alloc_rxb_page--;
+	rxb->page = NULL;
+}
+
+/* Called for REPLY_RX (legacy ABG frames), or
+ * REPLY_RX_MPDU_CMD (HT high-throughput N frames). */
+void iwl4965_rx_reply_rx(struct iwl_priv *priv,
+				struct iwl_rx_mem_buffer *rxb)
+{
+	struct ieee80211_hdr *header;
+	struct ieee80211_rx_status rx_status;
+	struct iwl_rx_packet *pkt = rxb_addr(rxb);
+	struct iwl_rx_phy_res *phy_res;
+	__le32 rx_pkt_status;
+	struct iwl_rx_mpdu_res_start *amsdu;
+	u32 len;
+	u32 ampdu_status;
+	u32 rate_n_flags;
+
+	/**
+	 * REPLY_RX and REPLY_RX_MPDU_CMD are handled differently.
+	 *	REPLY_RX: physical layer info is in this buffer
+	 *	REPLY_RX_MPDU_CMD: physical layer info was sent in separate
+	 *		command and cached in priv->last_phy_res
+	 *
+	 * Here we set up local variables depending on which command is
+	 * received.
+	 */
+	if (pkt->hdr.cmd == REPLY_RX) {
+		phy_res = (struct iwl_rx_phy_res *)pkt->u.raw;
+		header = (struct ieee80211_hdr *)(pkt->u.raw + sizeof(*phy_res)
+				+ phy_res->cfg_phy_cnt);
+
+		len = le16_to_cpu(phy_res->byte_count);
+		rx_pkt_status = *(__le32 *)(pkt->u.raw + sizeof(*phy_res) +
+				phy_res->cfg_phy_cnt + len);
+		ampdu_status = le32_to_cpu(rx_pkt_status);
+	} else {
+		if (!priv->_4965.last_phy_res_valid) {
+			IWL_ERR(priv, "MPDU frame without cached PHY data\n");
+			return;
+		}
+		phy_res = &priv->_4965.last_phy_res;
+		amsdu = (struct iwl_rx_mpdu_res_start *)pkt->u.raw;
+		header = (struct ieee80211_hdr *)(pkt->u.raw + sizeof(*amsdu));
+		len = le16_to_cpu(amsdu->byte_count);
+		rx_pkt_status = *(__le32 *)(pkt->u.raw + sizeof(*amsdu) + len);
+		ampdu_status = iwl4965_translate_rx_status(priv,
+				le32_to_cpu(rx_pkt_status));
+	}
+
+	if ((unlikely(phy_res->cfg_phy_cnt > 20))) {
+		IWL_DEBUG_DROP(priv, "dsp size out of range [0,20]: %d/n",
+				phy_res->cfg_phy_cnt);
+		return;
+	}
+
+	if (!(rx_pkt_status & RX_RES_STATUS_NO_CRC32_ERROR) ||
+	    !(rx_pkt_status & RX_RES_STATUS_NO_RXE_OVERFLOW)) {
+		IWL_DEBUG_RX(priv, "Bad CRC or FIFO: 0x%08X.\n",
+				le32_to_cpu(rx_pkt_status));
+		return;
+	}
+
+	/* This will be used in several places later */
+	rate_n_flags = le32_to_cpu(phy_res->rate_n_flags);
+
+	/* rx_status carries information about the packet to mac80211 */
+	rx_status.mactime = le64_to_cpu(phy_res->timestamp);
+	rx_status.freq =
+		ieee80211_channel_to_frequency(le16_to_cpu(phy_res->channel),
+							rx_status.band);
+	rx_status.band = (phy_res->phy_flags & RX_RES_PHY_FLAGS_BAND_24_MSK) ?
+				IEEE80211_BAND_2GHZ : IEEE80211_BAND_5GHZ;
+	rx_status.rate_idx =
+		iwl4965_hwrate_to_mac80211_idx(rate_n_flags, rx_status.band);
+	rx_status.flag = 0;
+
+	/* TSF isn't reliable. In order to allow smooth user experience,
+	 * this W/A doesn't propagate it to the mac80211 */
+	/*rx_status.flag |= RX_FLAG_TSFT;*/
+
+	priv->ucode_beacon_time = le32_to_cpu(phy_res->beacon_time_stamp);
+
+	/* Find max signal strength (dBm) among 3 antenna/receiver chains */
+	rx_status.signal = iwl4965_calc_rssi(priv, phy_res);
+
+	iwl_legacy_dbg_log_rx_data_frame(priv, len, header);
+	IWL_DEBUG_STATS_LIMIT(priv, "Rssi %d, TSF %llu\n",
+		rx_status.signal, (unsigned long long)rx_status.mactime);
+
+	/*
+	 * "antenna number"
+	 *
+	 * It seems that the antenna field in the phy flags value
+	 * is actually a bit field. This is undefined by radiotap,
+	 * it wants an actual antenna number but I always get "7"
+	 * for most legacy frames I receive indicating that the
+	 * same frame was received on all three RX chains.
+	 *
+	 * I think this field should be removed in favor of a
+	 * new 802.11n radiotap field "RX chains" that is defined
+	 * as a bitmask.
+	 */
+	rx_status.antenna =
+		(le16_to_cpu(phy_res->phy_flags) & RX_RES_PHY_FLAGS_ANTENNA_MSK)
+		>> RX_RES_PHY_FLAGS_ANTENNA_POS;
+
+	/* set the preamble flag if appropriate */
+	if (phy_res->phy_flags & RX_RES_PHY_FLAGS_SHORT_PREAMBLE_MSK)
+		rx_status.flag |= RX_FLAG_SHORTPRE;
+
+	/* Set up the HT phy flags */
+	if (rate_n_flags & RATE_MCS_HT_MSK)
+		rx_status.flag |= RX_FLAG_HT;
+	if (rate_n_flags & RATE_MCS_HT40_MSK)
+		rx_status.flag |= RX_FLAG_40MHZ;
+	if (rate_n_flags & RATE_MCS_SGI_MSK)
+		rx_status.flag |= RX_FLAG_SHORT_GI;
+
+	iwl4965_pass_packet_to_mac80211(priv, header, len, ampdu_status,
+				    rxb, &rx_status);
+}
+
+/* Cache phy data (Rx signal strength, etc) for HT frame (REPLY_RX_PHY_CMD).
+ * This will be used later in iwl_rx_reply_rx() for REPLY_RX_MPDU_CMD. */
+void iwl4965_rx_reply_rx_phy(struct iwl_priv *priv,
+			    struct iwl_rx_mem_buffer *rxb)
+{
+	struct iwl_rx_packet *pkt = rxb_addr(rxb);
+	priv->_4965.last_phy_res_valid = true;
+	memcpy(&priv->_4965.last_phy_res, pkt->u.raw,
+	       sizeof(struct iwl_rx_phy_res));
+}
+
+static int iwl4965_get_single_channel_for_scan(struct iwl_priv *priv,
+					   struct ieee80211_vif *vif,
+					   enum ieee80211_band band,
+					   struct iwl_scan_channel *scan_ch)
+{
+	const struct ieee80211_supported_band *sband;
+	u16 passive_dwell = 0;
+	u16 active_dwell = 0;
+	int added = 0;
+	u16 channel = 0;
+
+	sband = iwl_get_hw_mode(priv, band);
+	if (!sband) {
+		IWL_ERR(priv, "invalid band\n");
+		return added;
+	}
+
+	active_dwell = iwl_legacy_get_active_dwell_time(priv, band, 0);
+	passive_dwell = iwl_legacy_get_passive_dwell_time(priv, band, vif);
+
+	if (passive_dwell <= active_dwell)
+		passive_dwell = active_dwell + 1;
+
+	channel = iwl_legacy_get_single_channel_number(priv, band);
+	if (channel) {
+		scan_ch->channel = cpu_to_le16(channel);
+		scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
+		scan_ch->active_dwell = cpu_to_le16(active_dwell);
+		scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
+		/* Set txpower levels to defaults */
+		scan_ch->dsp_atten = 110;
+		if (band == IEEE80211_BAND_5GHZ)
+			scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
+		else
+			scan_ch->tx_gain = ((1 << 5) | (5 << 3));
+		added++;
+	} else
+		IWL_ERR(priv, "no valid channel found\n");
+	return added;
+}
+
+static int iwl4965_get_channels_for_scan(struct iwl_priv *priv,
+				     struct ieee80211_vif *vif,
+				     enum ieee80211_band band,
+				     u8 is_active, u8 n_probes,
+				     struct iwl_scan_channel *scan_ch)
+{
+	struct ieee80211_channel *chan;
+	const struct ieee80211_supported_band *sband;
+	const struct iwl_channel_info *ch_info;
+	u16 passive_dwell = 0;
+	u16 active_dwell = 0;
+	int added, i;
+	u16 channel;
+
+	sband = iwl_get_hw_mode(priv, band);
+	if (!sband)
+		return 0;
+
+	active_dwell = iwl_legacy_get_active_dwell_time(priv, band, n_probes);
+	passive_dwell = iwl_legacy_get_passive_dwell_time(priv, band, vif);
+
+	if (passive_dwell <= active_dwell)
+		passive_dwell = active_dwell + 1;
+
+	for (i = 0, added = 0; i < priv->scan_request->n_channels; i++) {
+		chan = priv->scan_request->channels[i];
+
+		if (chan->band != band)
+			continue;
+
+		channel = chan->hw_value;
+		scan_ch->channel = cpu_to_le16(channel);
+
+		ch_info = iwl_legacy_get_channel_info(priv, band, channel);
+		if (!iwl_legacy_is_channel_valid(ch_info)) {
+			IWL_DEBUG_SCAN(priv,
+				 "Channel %d is INVALID for this band.\n",
+					channel);
+			continue;
+		}
+
+		if (!is_active || iwl_legacy_is_channel_passive(ch_info) ||
+		    (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN))
+			scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
+		else
+			scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;
+
+		if (n_probes)
+			scan_ch->type |= IWL_SCAN_PROBE_MASK(n_probes);
+
+		scan_ch->active_dwell = cpu_to_le16(active_dwell);
+		scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
+
+		/* Set txpower levels to defaults */
+		scan_ch->dsp_atten = 110;
+
+		/* NOTE: if we were doing 6Mb OFDM for scans we'd use
+		 * power level:
+		 * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
+		 */
+		if (band == IEEE80211_BAND_5GHZ)
+			scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
+		else
+			scan_ch->tx_gain = ((1 << 5) | (5 << 3));
+
+		IWL_DEBUG_SCAN(priv, "Scanning ch=%d prob=0x%X [%s %d]\n",
+			       channel, le32_to_cpu(scan_ch->type),
+			       (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
+				"ACTIVE" : "PASSIVE",
+			       (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
+			       active_dwell : passive_dwell);
+
+		scan_ch++;
+		added++;
+	}
+
+	IWL_DEBUG_SCAN(priv, "total channels to scan %d\n", added);
+	return added;
+}
+
+int iwl4965_request_scan(struct iwl_priv *priv, struct ieee80211_vif *vif)
+{
+	struct iwl_host_cmd cmd = {
+		.id = REPLY_SCAN_CMD,
+		.len = sizeof(struct iwl_scan_cmd),
+		.flags = CMD_SIZE_HUGE,
+	};
+	struct iwl_scan_cmd *scan;
+	struct iwl_rxon_context *ctx = &priv->contexts[IWL_RXON_CTX_BSS];
+	u32 rate_flags = 0;
+	u16 cmd_len;
+	u16 rx_chain = 0;
+	enum ieee80211_band band;
+	u8 n_probes = 0;
+	u8 rx_ant = priv->hw_params.valid_rx_ant;
+	u8 rate;
+	bool is_active = false;
+	int  chan_mod;
+	u8 active_chains;
+	u8 scan_tx_antennas = priv->hw_params.valid_tx_ant;
+	int ret;
+
+	lockdep_assert_held(&priv->mutex);
+
+	if (vif)
+		ctx = iwl_legacy_rxon_ctx_from_vif(vif);
+
+	if (!priv->scan_cmd) {
+		priv->scan_cmd = kmalloc(sizeof(struct iwl_scan_cmd) +
+					 IWL_MAX_SCAN_SIZE, GFP_KERNEL);
+		if (!priv->scan_cmd) {
+			IWL_DEBUG_SCAN(priv,
+				       "fail to allocate memory for scan\n");
+			return -ENOMEM;
+		}
+	}
+	scan = priv->scan_cmd;
+	memset(scan, 0, sizeof(struct iwl_scan_cmd) + IWL_MAX_SCAN_SIZE);
+
+	scan->quiet_plcp_th = IWL_PLCP_QUIET_THRESH;
+	scan->quiet_time = IWL_ACTIVE_QUIET_TIME;
+
+	if (iwl_legacy_is_any_associated(priv)) {
+		u16 interval = 0;
+		u32 extra;
+		u32 suspend_time = 100;
+		u32 scan_suspend_time = 100;
+
+		IWL_DEBUG_INFO(priv, "Scanning while associated...\n");
+		if (priv->is_internal_short_scan)
+			interval = 0;
+		else
+			interval = vif->bss_conf.beacon_int;
+
+		scan->suspend_time = 0;
+		scan->max_out_time = cpu_to_le32(200 * 1024);
+		if (!interval)
+			interval = suspend_time;
+
+		extra = (suspend_time / interval) << 22;
+		scan_suspend_time = (extra |
+		    ((suspend_time % interval) * 1024));
+		scan->suspend_time = cpu_to_le32(scan_suspend_time);
+		IWL_DEBUG_SCAN(priv, "suspend_time 0x%X beacon interval %d\n",
+			       scan_suspend_time, interval);
+	}
+
+	if (priv->is_internal_short_scan) {
+		IWL_DEBUG_SCAN(priv, "Start internal passive scan.\n");
+	} else if (priv->scan_request->n_ssids) {
+		int i, p = 0;
+		IWL_DEBUG_SCAN(priv, "Kicking off active scan\n");
+		for (i = 0; i < priv->scan_request->n_ssids; i++) {
+			/* always does wildcard anyway */
+			if (!priv->scan_request->ssids[i].ssid_len)
+				continue;
+			scan->direct_scan[p].id = WLAN_EID_SSID;
+			scan->direct_scan[p].len =
+				priv->scan_request->ssids[i].ssid_len;
+			memcpy(scan->direct_scan[p].ssid,
+			       priv->scan_request->ssids[i].ssid,
+			       priv->scan_request->ssids[i].ssid_len);
+			n_probes++;
+			p++;
+		}
+		is_active = true;
+	} else
+		IWL_DEBUG_SCAN(priv, "Start passive scan.\n");
+
+	scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
+	scan->tx_cmd.sta_id = ctx->bcast_sta_id;
+	scan->tx_cmd.stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
+
+	switch (priv->scan_band) {
+	case IEEE80211_BAND_2GHZ:
+		scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
+		chan_mod = le32_to_cpu(
+			priv->contexts[IWL_RXON_CTX_BSS].active.flags &
+						RXON_FLG_CHANNEL_MODE_MSK)
+				       >> RXON_FLG_CHANNEL_MODE_POS;
+		if (chan_mod == CHANNEL_MODE_PURE_40) {
+			rate = IWL_RATE_6M_PLCP;
+		} else {
+			rate = IWL_RATE_1M_PLCP;
+			rate_flags = RATE_MCS_CCK_MSK;
+		}
+		break;
+	case IEEE80211_BAND_5GHZ:
+		rate = IWL_RATE_6M_PLCP;
+		break;
+	default:
+		IWL_WARN(priv, "Invalid scan band\n");
+		return -EIO;
+	}
+
+	/*
+	 * If active scanning is requested but a certain channel is
+	 * marked passive, we can do active scanning if we detect
+	 * transmissions.
+	 *
+	 * There is an issue with some firmware versions that triggers
+	 * a sysassert on a "good CRC threshold" of zero (== disabled),
+	 * on a radar channel even though this means that we should NOT
+	 * send probes.
+	 *
+	 * The "good CRC threshold" is the number of frames that we
+	 * need to receive during our dwell time on a channel before
+	 * sending out probes -- setting this to a huge value will
+	 * mean we never reach it, but at the same time work around
+	 * the aforementioned issue. Thus use IWL_GOOD_CRC_TH_NEVER
+	 * here instead of IWL_GOOD_CRC_TH_DISABLED.
+	 */
+	scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH_DEFAULT :
+					IWL_GOOD_CRC_TH_NEVER;
+
+	band = priv->scan_band;
+
+	if (priv->cfg->scan_rx_antennas[band])
+		rx_ant = priv->cfg->scan_rx_antennas[band];
+
+	if (priv->cfg->scan_tx_antennas[band])
+		scan_tx_antennas = priv->cfg->scan_tx_antennas[band];
+
+	priv->scan_tx_ant[band] = iwl4965_toggle_tx_ant(priv,
+						priv->scan_tx_ant[band],
+						    scan_tx_antennas);
+	rate_flags |= iwl4965_ant_idx_to_flags(priv->scan_tx_ant[band]);
+	scan->tx_cmd.rate_n_flags = iwl4965_hw_set_rate_n_flags(rate, rate_flags);
+
+	/* In power save mode use one chain, otherwise use all chains */
+	if (test_bit(STATUS_POWER_PMI, &priv->status)) {
+		/* rx_ant has been set to all valid chains previously */
+		active_chains = rx_ant &
+				((u8)(priv->chain_noise_data.active_chains));
+		if (!active_chains)
+			active_chains = rx_ant;
+
+		IWL_DEBUG_SCAN(priv, "chain_noise_data.active_chains: %u\n",
+				priv->chain_noise_data.active_chains);
+
+		rx_ant = iwl4965_first_antenna(active_chains);
+	}
+
+	/* MIMO is not used here, but value is required */
+	rx_chain |= priv->hw_params.valid_rx_ant << RXON_RX_CHAIN_VALID_POS;
+	rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS;
+	rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_SEL_POS;
+	rx_chain |= 0x1 << RXON_RX_CHAIN_DRIVER_FORCE_POS;
+	scan->rx_chain = cpu_to_le16(rx_chain);
+	if (!priv->is_internal_short_scan) {
+		cmd_len = iwl_legacy_fill_probe_req(priv,
+					(struct ieee80211_mgmt *)scan->data,
+					vif->addr,
+					priv->scan_request->ie,
+					priv->scan_request->ie_len,
+					IWL_MAX_SCAN_SIZE - sizeof(*scan));
+	} else {
+		/* use bcast addr, will not be transmitted but must be valid */
+		cmd_len = iwl_legacy_fill_probe_req(priv,
+					(struct ieee80211_mgmt *)scan->data,
+					iwl_bcast_addr, NULL, 0,
+					IWL_MAX_SCAN_SIZE - sizeof(*scan));
+
+	}
+	scan->tx_cmd.len = cpu_to_le16(cmd_len);
+
+	scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
+			       RXON_FILTER_BCON_AWARE_MSK);
+
+	if (priv->is_internal_short_scan) {
+		scan->channel_count =
+			iwl4965_get_single_channel_for_scan(priv, vif, band,
+				(void *)&scan->data[le16_to_cpu(
+				scan->tx_cmd.len)]);
+	} else {
+		scan->channel_count =
+			iwl4965_get_channels_for_scan(priv, vif, band,
+				is_active, n_probes,
+				(void *)&scan->data[le16_to_cpu(
+				scan->tx_cmd.len)]);
+	}
+	if (scan->channel_count == 0) {
+		IWL_DEBUG_SCAN(priv, "channel count %d\n", scan->channel_count);
+		return -EIO;
+	}
+
+	cmd.len += le16_to_cpu(scan->tx_cmd.len) +
+	    scan->channel_count * sizeof(struct iwl_scan_channel);
+	cmd.data = scan;
+	scan->len = cpu_to_le16(cmd.len);
+
+	set_bit(STATUS_SCAN_HW, &priv->status);
+
+	ret = iwl_legacy_send_cmd_sync(priv, &cmd);
+	if (ret)
+		clear_bit(STATUS_SCAN_HW, &priv->status);
+
+	return ret;
+}
+
+int iwl4965_manage_ibss_station(struct iwl_priv *priv,
+			       struct ieee80211_vif *vif, bool add)
+{
+	struct iwl_vif_priv *vif_priv = (void *)vif->drv_priv;
+
+	if (add)
+		return iwl4965_add_bssid_station(priv, vif_priv->ctx,
+						vif->bss_conf.bssid,
+						&vif_priv->ibss_bssid_sta_id);
+	return iwl_legacy_remove_station(priv, vif_priv->ibss_bssid_sta_id,
+				  vif->bss_conf.bssid);
+}
+
+void iwl4965_free_tfds_in_queue(struct iwl_priv *priv,
+			    int sta_id, int tid, int freed)
+{
+	lockdep_assert_held(&priv->sta_lock);
+
+	if (priv->stations[sta_id].tid[tid].tfds_in_queue >= freed)
+		priv->stations[sta_id].tid[tid].tfds_in_queue -= freed;
+	else {
+		IWL_DEBUG_TX(priv, "free more than tfds_in_queue (%u:%d)\n",
+			priv->stations[sta_id].tid[tid].tfds_in_queue,
+			freed);
+		priv->stations[sta_id].tid[tid].tfds_in_queue = 0;
+	}
+}
+
+#define IWL_TX_QUEUE_MSK	0xfffff
+
+static bool iwl4965_is_single_rx_stream(struct iwl_priv *priv)
+{
+	return priv->current_ht_config.smps == IEEE80211_SMPS_STATIC ||
+	       priv->current_ht_config.single_chain_sufficient;
+}
+
+#define IWL_NUM_RX_CHAINS_MULTIPLE	3
+#define IWL_NUM_RX_CHAINS_SINGLE	2
+#define IWL_NUM_IDLE_CHAINS_DUAL	2
+#define IWL_NUM_IDLE_CHAINS_SINGLE	1
+
+/*
+ * Determine how many receiver/antenna chains to use.
+ *
+ * More provides better reception via diversity.  Fewer saves power
+ * at the expense of throughput, but only when not in powersave to
+ * start with.
+ *
+ * MIMO (dual stream) requires at least 2, but works better with 3.
+ * This does not determine *which* chains to use, just how many.
+ */
+static int iwl4965_get_active_rx_chain_count(struct iwl_priv *priv)
+{
+	/* # of Rx chains to use when expecting MIMO. */
+	if (iwl4965_is_single_rx_stream(priv))
+		return IWL_NUM_RX_CHAINS_SINGLE;
+	else
+		return IWL_NUM_RX_CHAINS_MULTIPLE;
+}
+
+/*
+ * When we are in power saving mode, unless device support spatial
+ * multiplexing power save, use the active count for rx chain count.
+ */
+static int
+iwl4965_get_idle_rx_chain_count(struct iwl_priv *priv, int active_cnt)
+{
+	/* # Rx chains when idling, depending on SMPS mode */
+	switch (priv->current_ht_config.smps) {
+	case IEEE80211_SMPS_STATIC:
+	case IEEE80211_SMPS_DYNAMIC:
+		return IWL_NUM_IDLE_CHAINS_SINGLE;
+	case IEEE80211_SMPS_OFF:
+		return active_cnt;
+	default:
+		WARN(1, "invalid SMPS mode %d",
+		     priv->current_ht_config.smps);
+		return active_cnt;
+	}
+}
+
+/* up to 4 chains */
+static u8 iwl4965_count_chain_bitmap(u32 chain_bitmap)
+{
+	u8 res;
+	res = (chain_bitmap & BIT(0)) >> 0;
+	res += (chain_bitmap & BIT(1)) >> 1;
+	res += (chain_bitmap & BIT(2)) >> 2;
+	res += (chain_bitmap & BIT(3)) >> 3;
+	return res;
+}
+
+/**
+ * iwl4965_set_rxon_chain - Set up Rx chain usage in "staging" RXON image
+ *
+ * Selects how many and which Rx receivers/antennas/chains to use.
+ * This should not be used for scan command ... it puts data in wrong place.
+ */
+void iwl4965_set_rxon_chain(struct iwl_priv *priv, struct iwl_rxon_context *ctx)
+{
+	bool is_single = iwl4965_is_single_rx_stream(priv);
+	bool is_cam = !test_bit(STATUS_POWER_PMI, &priv->status);
+	u8 idle_rx_cnt, active_rx_cnt, valid_rx_cnt;
+	u32 active_chains;
+	u16 rx_chain;
+
+	/* Tell uCode which antennas are actually connected.
+	 * Before first association, we assume all antennas are connected.
+	 * Just after first association, iwl4965_chain_noise_calibration()
+	 *    checks which antennas actually *are* connected. */
+	if (priv->chain_noise_data.active_chains)
+		active_chains = priv->chain_noise_data.active_chains;
+	else
+		active_chains = priv->hw_params.valid_rx_ant;
+
+	rx_chain = active_chains << RXON_RX_CHAIN_VALID_POS;
+
+	/* How many receivers should we use? */
+	active_rx_cnt = iwl4965_get_active_rx_chain_count(priv);
+	idle_rx_cnt = iwl4965_get_idle_rx_chain_count(priv, active_rx_cnt);
+
+
+	/* correct rx chain count according hw settings
+	 * and chain noise calibration
+	 */
+	valid_rx_cnt = iwl4965_count_chain_bitmap(active_chains);
+	if (valid_rx_cnt < active_rx_cnt)
+		active_rx_cnt = valid_rx_cnt;
+
+	if (valid_rx_cnt < idle_rx_cnt)
+		idle_rx_cnt = valid_rx_cnt;
+
+	rx_chain |= active_rx_cnt << RXON_RX_CHAIN_MIMO_CNT_POS;
+	rx_chain |= idle_rx_cnt  << RXON_RX_CHAIN_CNT_POS;
+
+	ctx->staging.rx_chain = cpu_to_le16(rx_chain);
+
+	if (!is_single && (active_rx_cnt >= IWL_NUM_RX_CHAINS_SINGLE) && is_cam)
+		ctx->staging.rx_chain |= RXON_RX_CHAIN_MIMO_FORCE_MSK;
+	else
+		ctx->staging.rx_chain &= ~RXON_RX_CHAIN_MIMO_FORCE_MSK;
+
+	IWL_DEBUG_ASSOC(priv, "rx_chain=0x%X active=%d idle=%d\n",
+			ctx->staging.rx_chain,
+			active_rx_cnt, idle_rx_cnt);
+
+	WARN_ON(active_rx_cnt == 0 || idle_rx_cnt == 0 ||
+		active_rx_cnt < idle_rx_cnt);
+}
+
+u8 iwl4965_toggle_tx_ant(struct iwl_priv *priv, u8 ant, u8 valid)
+{
+	int i;
+	u8 ind = ant;
+
+	for (i = 0; i < RATE_ANT_NUM - 1; i++) {
+		ind = (ind + 1) < RATE_ANT_NUM ?  ind + 1 : 0;
+		if (valid & BIT(ind))
+			return ind;
+	}
+	return ant;
+}
+
+static const char *iwl4965_get_fh_string(int cmd)
+{
+	switch (cmd) {
+	IWL_CMD(FH_RSCSR_CHNL0_STTS_WPTR_REG);
+	IWL_CMD(FH_RSCSR_CHNL0_RBDCB_BASE_REG);
+	IWL_CMD(FH_RSCSR_CHNL0_WPTR);
+	IWL_CMD(FH_MEM_RCSR_CHNL0_CONFIG_REG);
+	IWL_CMD(FH_MEM_RSSR_SHARED_CTRL_REG);
+	IWL_CMD(FH_MEM_RSSR_RX_STATUS_REG);
+	IWL_CMD(FH_MEM_RSSR_RX_ENABLE_ERR_IRQ2DRV);
+	IWL_CMD(FH_TSSR_TX_STATUS_REG);
+	IWL_CMD(FH_TSSR_TX_ERROR_REG);
+	default:
+		return "UNKNOWN";
+	}
+}
+
+int iwl4965_dump_fh(struct iwl_priv *priv, char **buf, bool display)
+{
+	int i;
+#ifdef CONFIG_IWLWIFI_LEGACY_DEBUG
+	int pos = 0;
+	size_t bufsz = 0;
+#endif
+	static const u32 fh_tbl[] = {
+		FH_RSCSR_CHNL0_STTS_WPTR_REG,
+		FH_RSCSR_CHNL0_RBDCB_BASE_REG,
+		FH_RSCSR_CHNL0_WPTR,
+		FH_MEM_RCSR_CHNL0_CONFIG_REG,
+		FH_MEM_RSSR_SHARED_CTRL_REG,
+		FH_MEM_RSSR_RX_STATUS_REG,
+		FH_MEM_RSSR_RX_ENABLE_ERR_IRQ2DRV,
+		FH_TSSR_TX_STATUS_REG,
+		FH_TSSR_TX_ERROR_REG
+	};
+#ifdef CONFIG_IWLWIFI_LEGACY_DEBUG
+	if (display) {
+		bufsz = ARRAY_SIZE(fh_tbl) * 48 + 40;
+		*buf = kmalloc(bufsz, GFP_KERNEL);
+		if (!*buf)
+			return -ENOMEM;
+		pos += scnprintf(*buf + pos, bufsz - pos,
+				"FH register values:\n");
+		for (i = 0; i < ARRAY_SIZE(fh_tbl); i++) {
+			pos += scnprintf(*buf + pos, bufsz - pos,
+				"  %34s: 0X%08x\n",
+				iwl4965_get_fh_string(fh_tbl[i]),
+				iwl_legacy_read_direct32(priv, fh_tbl[i]));
+		}
+		return pos;
+	}
+#endif
+	IWL_ERR(priv, "FH register values:\n");
+	for (i = 0; i <  ARRAY_SIZE(fh_tbl); i++) {
+		IWL_ERR(priv, "  %34s: 0X%08x\n",
+			iwl4965_get_fh_string(fh_tbl[i]),
+			iwl_legacy_read_direct32(priv, fh_tbl[i]));
+	}
+	return 0;
+}