htt_rx.c

/*
 * Copyright (c) 2005-2011 Atheros Communications Inc.
 * Copyright (c) 2011-2013 Qualcomm Atheros, Inc.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include "core.h"
#include "htc.h"
#include "htt.h"
#include "txrx.h"
#include "debug.h"
#include "trace.h"
#include "mac.h"

#include <linux/log2.h>

#define HTT_RX_RING_SIZE HTT_RX_RING_SIZE_MAX
#define HTT_RX_RING_FILL_LEVEL (((HTT_RX_RING_SIZE) / 2) - 1)

/* when under memory pressure rx ring refill may fail and needs a retry */
#define HTT_RX_RING_REFILL_RETRY_MS 50

static int ath10k_htt_rx_get_csum_state(struct sk_buff *skb);
static void ath10k_htt_txrx_compl_task(unsigned long ptr);

static struct sk_buff *
ath10k_htt_rx_find_skb_paddr(struct ath10k *ar, u32 paddr)
{
	struct ath10k_skb_rxcb *rxcb;

	hash_for_each_possible(ar->htt.rx_ring.skb_table, rxcb, hlist, paddr)
		if (rxcb->paddr == paddr)
			return ATH10K_RXCB_SKB(rxcb);

	WARN_ON_ONCE(1);
	return NULL;
}

static void ath10k_htt_rx_ring_free(struct ath10k_htt *htt)
{
	struct sk_buff *skb;
	struct ath10k_skb_rxcb *rxcb;
	struct hlist_node *n;
	int i;

	if (htt->rx_ring.in_ord_rx) {
		hash_for_each_safe(htt->rx_ring.skb_table, i, n, rxcb, hlist) {
			skb = ATH10K_RXCB_SKB(rxcb);
			dma_unmap_single(htt->ar->dev, rxcb->paddr,
					 skb->len + skb_tailroom(skb),
					 DMA_FROM_DEVICE);
			hash_del(&rxcb->hlist);
			dev_kfree_skb_any(skb);
		}
	} else {
		for (i = 0; i < htt->rx_ring.size; i++) {
			skb = htt->rx_ring.netbufs_ring[i];
			if (!skb)
				continue;

			rxcb = ATH10K_SKB_RXCB(skb);
			dma_unmap_single(htt->ar->dev, rxcb->paddr,
					 skb->len + skb_tailroom(skb),
					 DMA_FROM_DEVICE);
			dev_kfree_skb_any(skb);
		}
	}

	htt->rx_ring.fill_cnt = 0;
	hash_init(htt->rx_ring.skb_table);
	memset(htt->rx_ring.netbufs_ring, 0,
	       htt->rx_ring.size * sizeof(htt->rx_ring.netbufs_ring[0]));
}

static int __ath10k_htt_rx_ring_fill_n(struct ath10k_htt *htt, int num)
{
	struct htt_rx_desc *rx_desc;
	struct ath10k_skb_rxcb *rxcb;
	struct sk_buff *skb;
	dma_addr_t paddr;
	int ret = 0, idx;

	/* The Full Rx Reorder firmware has no way of telling the host
	 * implicitly when it copied HTT Rx Ring buffers to MAC Rx Ring.
	 * To keep things simple make sure ring is always half empty. This
	 * guarantees there'll be no replenishment overruns possible.
	 */
	BUILD_BUG_ON(HTT_RX_RING_FILL_LEVEL >= HTT_RX_RING_SIZE / 2);

	idx = __le32_to_cpu(*htt->rx_ring.alloc_idx.vaddr);
	while (num > 0) {
		skb = dev_alloc_skb(HTT_RX_BUF_SIZE + HTT_RX_DESC_ALIGN);
		if (!skb) {
			ret = -ENOMEM;
			goto fail;
		}

		if (!IS_ALIGNED((unsigned long)skb->data, HTT_RX_DESC_ALIGN))
			skb_pull(skb,
				 PTR_ALIGN(skb->data, HTT_RX_DESC_ALIGN) -
				 skb->data);

		/* Clear rx_desc attention word before posting to Rx ring */
		rx_desc = (struct htt_rx_desc *)skb->data;
		rx_desc->attention.flags = __cpu_to_le32(0);

		paddr = dma_map_single(htt->ar->dev, skb->data,
				       skb->len + skb_tailroom(skb),
				       DMA_FROM_DEVICE);

		if (unlikely(dma_mapping_error(htt->ar->dev, paddr))) {
			dev_kfree_skb_any(skb);
			ret = -ENOMEM;
			goto fail;
		}

		rxcb = ATH10K_SKB_RXCB(skb);
		rxcb->paddr = paddr;
		htt->rx_ring.netbufs_ring[idx] = skb;
		htt->rx_ring.paddrs_ring[idx] = __cpu_to_le32(paddr);
		htt->rx_ring.fill_cnt++;

		if (htt->rx_ring.in_ord_rx) {
			hash_add(htt->rx_ring.skb_table,
				 &ATH10K_SKB_RXCB(skb)->hlist,
				 (u32)paddr);
		}

		num--;
		idx++;
		idx &= htt->rx_ring.size_mask;
	}

fail:
	/*
	 * Make sure the rx buffer is updated before available buffer
	 * index to avoid any potential rx ring corruption.
	 */
	mb();
	*htt->rx_ring.alloc_idx.vaddr = __cpu_to_le32(idx);
	return ret;
}

static int ath10k_htt_rx_ring_fill_n(struct ath10k_htt *htt, int num)
{
	lockdep_assert_held(&htt->rx_ring.lock);
	return __ath10k_htt_rx_ring_fill_n(htt, num);
}

static void ath10k_htt_rx_msdu_buff_replenish(struct ath10k_htt *htt)
{
	int ret, num_deficit, num_to_fill;

	/* Refilling the whole RX ring buffer proves to be a bad idea. The
	 * reason is RX may take up significant amount of CPU cycles and starve
	 * other tasks, e.g. TX on an ethernet device while acting as a bridge
	 * with ath10k wlan interface. This ended up with very poor performance
	 * once CPU the host system was overwhelmed with RX on ath10k.
	 *
	 * By limiting the number of refills the replenishing occurs
	 * progressively. This in turns makes use of the fact tasklets are
	 * processed in FIFO order. This means actual RX processing can starve
	 * out refilling. If there's not enough buffers on RX ring FW will not
	 * report RX until it is refilled with enough buffers. This
	 * automatically balances load wrt to CPU power.
	 *
	 * This probably comes at a cost of lower maximum throughput but
	 * improves the average and stability. */
	spin_lock_bh(&htt->rx_ring.lock);
	num_deficit = htt->rx_ring.fill_level - htt->rx_ring.fill_cnt;
	num_to_fill = min(ATH10K_HTT_MAX_NUM_REFILL, num_deficit);
	num_deficit -= num_to_fill;
	ret = ath10k_htt_rx_ring_fill_n(htt, num_to_fill);
	if (ret == -ENOMEM) {
		/*
		 * Failed to fill it to the desired level -
		 * we'll start a timer and try again next time.
		 * As long as enough buffers are left in the ring for
		 * another A-MPDU rx, no special recovery is needed.
		 */
		mod_timer(&htt->rx_ring.refill_retry_timer, jiffies +
			  msecs_to_jiffies(HTT_RX_RING_REFILL_RETRY_MS));
	} else if (num_deficit > 0) {
		tasklet_schedule(&htt->rx_replenish_task);
	}
	spin_unlock_bh(&htt->rx_ring.lock);
}

static void ath10k_htt_rx_ring_refill_retry(unsigned long arg)
{
	struct ath10k_htt *htt = (struct ath10k_htt *)arg;

	ath10k_htt_rx_msdu_buff_replenish(htt);
}

int ath10k_htt_rx_ring_refill(struct ath10k *ar)
{
	struct ath10k_htt *htt = &ar->htt;
	int ret;

	spin_lock_bh(&htt->rx_ring.lock);
	ret = ath10k_htt_rx_ring_fill_n(htt, (htt->rx_ring.fill_level -
					      htt->rx_ring.fill_cnt));
	spin_unlock_bh(&htt->rx_ring.lock);

	if (ret)
		ath10k_htt_rx_ring_free(htt);

	return ret;
}

void ath10k_htt_rx_free(struct ath10k_htt *htt)
{
	del_timer_sync(&htt->rx_ring.refill_retry_timer);
	tasklet_kill(&htt->rx_replenish_task);
	tasklet_kill(&htt->txrx_compl_task);

	skb_queue_purge(&htt->rx_compl_q);
	skb_queue_purge(&htt->rx_in_ord_compl_q);
	skb_queue_purge(&htt->tx_fetch_ind_q);

	ath10k_htt_rx_ring_free(htt);

	dma_free_coherent(htt->ar->dev,
			  (htt->rx_ring.size *
			   sizeof(htt->rx_ring.paddrs_ring)),
			  htt->rx_ring.paddrs_ring,
			  htt->rx_ring.base_paddr);

	dma_free_coherent(htt->ar->dev,
			  sizeof(*htt->rx_ring.alloc_idx.vaddr),
			  htt->rx_ring.alloc_idx.vaddr,
			  htt->rx_ring.alloc_idx.paddr);

	kfree(htt->rx_ring.netbufs_ring);
}

static inline struct sk_buff *ath10k_htt_rx_netbuf_pop(struct ath10k_htt *htt)
{
	struct ath10k *ar = htt->ar;
	int idx;
	struct sk_buff *msdu;

	lockdep_assert_held(&htt->rx_ring.lock);

	if (htt->rx_ring.fill_cnt == 0) {
		ath10k_warn(ar, "tried to pop sk_buff from an empty rx ring\n");
		return NULL;
	}

	idx = htt->rx_ring.sw_rd_idx.msdu_payld;
	msdu = htt->rx_ring.netbufs_ring[idx];
	htt->rx_ring.netbufs_ring[idx] = NULL;
	htt->rx_ring.paddrs_ring[idx] = 0;

	idx++;
	idx &= htt->rx_ring.size_mask;
	htt->rx_ring.sw_rd_idx.msdu_payld = idx;
	htt->rx_ring.fill_cnt--;

	dma_unmap_single(htt->ar->dev,
			 ATH10K_SKB_RXCB(msdu)->paddr,
			 msdu->len + skb_tailroom(msdu),
			 DMA_FROM_DEVICE);
	ath10k_dbg_dump(ar, ATH10K_DBG_HTT_DUMP, NULL, "htt rx netbuf pop: ",
			msdu->data, msdu->len + skb_tailroom(msdu));

	return msdu;
}

/* return: < 0 fatal error, 0 - non chained msdu, 1 chained msdu */
static int ath10k_htt_rx_amsdu_pop(struct ath10k_htt *htt,
				   struct sk_buff_head *amsdu)
{
	struct ath10k *ar = htt->ar;
	int msdu_len, msdu_chaining = 0;
	struct sk_buff *msdu;
	struct htt_rx_desc *rx_desc;

	lockdep_assert_held(&htt->rx_ring.lock);

	for (;;) {
		int last_msdu, msdu_len_invalid, msdu_chained;

		msdu = ath10k_htt_rx_netbuf_pop(htt);
		if (!msdu) {
			__skb_queue_purge(amsdu);
			return -ENOENT;
		}

		__skb_queue_tail(amsdu, msdu);

		rx_desc = (struct htt_rx_desc *)msdu->data;

		/* FIXME: we must report msdu payload since this is what caller
		 *        expects now */
		skb_put(msdu, offsetof(struct htt_rx_desc, msdu_payload));
		skb_pull(msdu, offsetof(struct htt_rx_desc, msdu_payload));

		/*
		 * Sanity check - confirm the HW is finished filling in the
		 * rx data.
		 * If the HW and SW are working correctly, then it's guaranteed
		 * that the HW's MAC DMA is done before this point in the SW.
		 * To prevent the case that we handle a stale Rx descriptor,
		 * just assert for now until we have a way to recover.
		 */
		if (!(__le32_to_cpu(rx_desc->attention.flags)
				& RX_ATTENTION_FLAGS_MSDU_DONE)) {
			__skb_queue_purge(amsdu);
			return -EIO;
		}

		msdu_len_invalid = !!(__le32_to_cpu(rx_desc->attention.flags)
					& (RX_ATTENTION_FLAGS_MPDU_LENGTH_ERR |
					   RX_ATTENTION_FLAGS_MSDU_LENGTH_ERR));
		msdu_len = MS(__le32_to_cpu(rx_desc->msdu_start.common.info0),
			      RX_MSDU_START_INFO0_MSDU_LENGTH);
		msdu_chained = rx_desc->frag_info.ring2_more_count;

		if (msdu_len_invalid)
			msdu_len = 0;

		skb_trim(msdu, 0);
		skb_put(msdu, min(msdu_len, HTT_RX_MSDU_SIZE));
		msdu_len -= msdu->len;

		/* Note: Chained buffers do not contain rx descriptor */
		while (msdu_chained--) {
			msdu = ath10k_htt_rx_netbuf_pop(htt);
			if (!msdu) {
				__skb_queue_purge(amsdu);
				return -ENOENT;
			}

			__skb_queue_tail(amsdu, msdu);
			skb_trim(msdu, 0);
			skb_put(msdu, min(msdu_len, HTT_RX_BUF_SIZE));
			msdu_len -= msdu->len;
			msdu_chaining = 1;
		}

		last_msdu = __le32_to_cpu(rx_desc->msdu_end.common.info0) &
				RX_MSDU_END_INFO0_LAST_MSDU;

		trace_ath10k_htt_rx_desc(ar, &rx_desc->attention,
					 sizeof(*rx_desc) - sizeof(u32));

		if (last_msdu)
			break;
	}

	if (skb_queue_empty(amsdu))
		msdu_chaining = -1;

	/*
	 * Don't refill the ring yet.
	 *
	 * First, the elements popped here are still in use - it is not
	 * safe to overwrite them until the matching call to
	 * mpdu_desc_list_next. Second, for efficiency it is preferable to
	 * refill the rx ring with 1 PPDU's worth of rx buffers (something
	 * like 32 x 3 buffers), rather than one MPDU's worth of rx buffers
	 * (something like 3 buffers). Consequently, we'll rely on the txrx
	 * SW to tell us when it is done pulling all the PPDU's rx buffers
	 * out of the rx ring, and then refill it just once.
	 */

	return msdu_chaining;
}

static void ath10k_htt_rx_replenish_task(unsigned long ptr)
{
	struct ath10k_htt *htt = (struct ath10k_htt *)ptr;

	ath10k_htt_rx_msdu_buff_replenish(htt);
}

static struct sk_buff *ath10k_htt_rx_pop_paddr(struct ath10k_htt *htt,
					       u32 paddr)
{
	struct ath10k *ar = htt->ar;
	struct ath10k_skb_rxcb *rxcb;
	struct sk_buff *msdu;

	lockdep_assert_held(&htt->rx_ring.lock);

	msdu = ath10k_htt_rx_find_skb_paddr(ar, paddr);
	if (!msdu)
		return NULL;

	rxcb = ATH10K_SKB_RXCB(msdu);
	hash_del(&rxcb->hlist);
	htt->rx_ring.fill_cnt--;

	dma_unmap_single(htt->ar->dev, rxcb->paddr,
			 msdu->len + skb_tailroom(msdu),
			 DMA_FROM_DEVICE);
	ath10k_dbg_dump(ar, ATH10K_DBG_HTT_DUMP, NULL, "htt rx netbuf pop: ",
			msdu->data, msdu->len + skb_tailroom(msdu));

	return msdu;
}

static int ath10k_htt_rx_pop_paddr_list(struct ath10k_htt *htt,
					struct htt_rx_in_ord_ind *ev,
					struct sk_buff_head *list)
{
	struct ath10k *ar = htt->ar;
	struct htt_rx_in_ord_msdu_desc *msdu_desc = ev->msdu_descs;
	struct htt_rx_desc *rxd;
	struct sk_buff *msdu;
	int msdu_count;
	bool is_offload;
	u32 paddr;

	lockdep_assert_held(&htt->rx_ring.lock);

	msdu_count = __le16_to_cpu(ev->msdu_count);
	is_offload = !!(ev->info & HTT_RX_IN_ORD_IND_INFO_OFFLOAD_MASK);

	while (msdu_count--) {
		paddr = __le32_to_cpu(msdu_desc->msdu_paddr);

		msdu = ath10k_htt_rx_pop_paddr(htt, paddr);
		if (!msdu) {
			__skb_queue_purge(list);
			return -ENOENT;
		}

		__skb_queue_tail(list, msdu);

		if (!is_offload) {
			rxd = (void *)msdu->data;

			trace_ath10k_htt_rx_desc(ar, rxd, sizeof(*rxd));

			skb_put(msdu, sizeof(*rxd));
			skb_pull(msdu, sizeof(*rxd));
			skb_put(msdu, __le16_to_cpu(msdu_desc->msdu_len));

			if (!(__le32_to_cpu(rxd->attention.flags) &
			      RX_ATTENTION_FLAGS_MSDU_DONE)) {
				ath10k_warn(htt->ar, "tried to pop an incomplete frame, oops!\n");
				return -EIO;
			}
		}

		msdu_desc++;
	}

	return 0;
}

int ath10k_htt_rx_alloc(struct ath10k_htt *htt)
{
	struct ath10k *ar = htt->ar;
	dma_addr_t paddr;
	void *vaddr;
	size_t size;
	struct timer_list *timer = &htt->rx_ring.refill_retry_timer;

	htt->rx_confused = false;

	/* XXX: The fill level could be changed during runtime in response to
	 * the host processing latency. Is this really worth it?
	 */
	htt->rx_ring.size = HTT_RX_RING_SIZE;
	htt->rx_ring.size_mask = htt->rx_ring.size - 1;
	htt->rx_ring.fill_level = HTT_RX_RING_FILL_LEVEL;

	if (!is_power_of_2(htt->rx_ring.size)) {
		ath10k_warn(ar, "htt rx ring size is not power of 2\n");
		return -EINVAL;
	}

	htt->rx_ring.netbufs_ring =
		kzalloc(htt->rx_ring.size * sizeof(struct sk_buff *),
			GFP_KERNEL);
	if (!htt->rx_ring.netbufs_ring)
		goto err_netbuf;

	size = htt->rx_ring.size * sizeof(htt->rx_ring.paddrs_ring);

	vaddr = dma_alloc_coherent(htt->ar->dev, size, &paddr, GFP_KERNEL);
	if (!vaddr)
		goto err_dma_ring;

	htt->rx_ring.paddrs_ring = vaddr;
	htt->rx_ring.base_paddr = paddr;

	vaddr = dma_alloc_coherent(htt->ar->dev,
				   sizeof(*htt->rx_ring.alloc_idx.vaddr),
				   &paddr, GFP_KERNEL);
	if (!vaddr)
		goto err_dma_idx;

	htt->rx_ring.alloc_idx.vaddr = vaddr;
	htt->rx_ring.alloc_idx.paddr = paddr;
	htt->rx_ring.sw_rd_idx.msdu_payld = htt->rx_ring.size_mask;
	*htt->rx_ring.alloc_idx.vaddr = 0;

	/* Initialize the Rx refill retry timer */
	setup_timer(timer, ath10k_htt_rx_ring_refill_retry, (unsigned long)htt);

	spin_lock_init(&htt->rx_ring.lock);

	htt->rx_ring.fill_cnt = 0;
	htt->rx_ring.sw_rd_idx.msdu_payld = 0;
	hash_init(htt->rx_ring.skb_table);

	tasklet_init(&htt->rx_replenish_task, ath10k_htt_rx_replenish_task,
		     (unsigned long)htt);

	skb_queue_head_init(&htt->rx_compl_q);
	skb_queue_head_init(&htt->rx_in_ord_compl_q);
	skb_queue_head_init(&htt->tx_fetch_ind_q);
	atomic_set(&htt->num_mpdus_ready, 0);

	tasklet_init(&htt->txrx_compl_task, ath10k_htt_txrx_compl_task,
		     (unsigned long)htt);

	ath10k_dbg(ar, ATH10K_DBG_BOOT, "htt rx ring size %d fill_level %d\n",
		   htt->rx_ring.size, htt->rx_ring.fill_level);
	return 0;

err_dma_idx:
	dma_free_coherent(htt->ar->dev,
			  (htt->rx_ring.size *
			   sizeof(htt->rx_ring.paddrs_ring)),
			  htt->rx_ring.paddrs_ring,
			  htt->rx_ring.base_paddr);
err_dma_ring:
	kfree(htt->rx_ring.netbufs_ring);
err_netbuf:
	return -ENOMEM;
}

static int ath10k_htt_rx_crypto_param_len(struct ath10k *ar,
					  enum htt_rx_mpdu_encrypt_type type)
{
	switch (type) {
	case HTT_RX_MPDU_ENCRYPT_NONE:
		return 0;
	case HTT_RX_MPDU_ENCRYPT_WEP40:
	case HTT_RX_MPDU_ENCRYPT_WEP104:
		return IEEE80211_WEP_IV_LEN;
	case HTT_RX_MPDU_ENCRYPT_TKIP_WITHOUT_MIC:
	case HTT_RX_MPDU_ENCRYPT_TKIP_WPA:
		return IEEE80211_TKIP_IV_LEN;
	case HTT_RX_MPDU_ENCRYPT_AES_CCM_WPA2:
		return IEEE80211_CCMP_HDR_LEN;
	case HTT_RX_MPDU_ENCRYPT_WEP128:
	case HTT_RX_MPDU_ENCRYPT_WAPI:
		break;
	}

	ath10k_warn(ar, "unsupported encryption type %d\n", type);
	return 0;
}

#define MICHAEL_MIC_LEN 8

static int ath10k_htt_rx_crypto_tail_len(struct ath10k *ar,
					 enum htt_rx_mpdu_encrypt_type type)
{
	switch (type) {
	case HTT_RX_MPDU_ENCRYPT_NONE:
		return 0;
	case HTT_RX_MPDU_ENCRYPT_WEP40:
	case HTT_RX_MPDU_ENCRYPT_WEP104:
		return IEEE80211_WEP_ICV_LEN;
	case HTT_RX_MPDU_ENCRYPT_TKIP_WITHOUT_MIC:
	case HTT_RX_MPDU_ENCRYPT_TKIP_WPA:
		return IEEE80211_TKIP_ICV_LEN;
	case HTT_RX_MPDU_ENCRYPT_AES_CCM_WPA2:
		return IEEE80211_CCMP_MIC_LEN;
	case HTT_RX_MPDU_ENCRYPT_WEP128:
	case HTT_RX_MPDU_ENCRYPT_WAPI:
		break;
	}

	ath10k_warn(ar, "unsupported encryption type %d\n", type);
	return 0;
}

struct amsdu_subframe_hdr {
	u8 dst[ETH_ALEN];
	u8 src[ETH_ALEN];
	__be16 len;
} __packed;

#define GROUP_ID_IS_SU_MIMO(x) ((x) == 0 || (x) == 63)

static void ath10k_htt_rx_h_rates(struct ath10k *ar,
				  struct ieee80211_rx_status *status,
				  struct htt_rx_desc *rxd)
{
	struct ieee80211_supported_band *sband;
	u8 cck, rate, bw, sgi, mcs, nss;
	u8 preamble = 0;
	u8 group_id;
	u32 info1, info2, info3;

	info1 = __le32_to_cpu(rxd->ppdu_start.info1);
	info2 = __le32_to_cpu(rxd->ppdu_start.info2);
	info3 = __le32_to_cpu(rxd->ppdu_start.info3);

	preamble = MS(info1, RX_PPDU_START_INFO1_PREAMBLE_TYPE);

	switch (preamble) {
	case HTT_RX_LEGACY:
		/* To get legacy rate index band is required. Since band can't
		 * be undefined check if freq is non-zero.
		 */
		if (!status->freq)
			return;

		cck = info1 & RX_PPDU_START_INFO1_L_SIG_RATE_SELECT;
		rate = MS(info1, RX_PPDU_START_INFO1_L_SIG_RATE);
		rate &= ~RX_PPDU_START_RATE_FLAG;

		sband = &ar->mac.sbands[status->band];
		status->rate_idx = ath10k_mac_hw_rate_to_idx(sband, rate, cck);
		break;
	case HTT_RX_HT:
	case HTT_RX_HT_WITH_TXBF:
		/* HT-SIG - Table 20-11 in info2 and info3 */
		mcs = info2 & 0x1F;
		nss = mcs >> 3;
		bw = (info2 >> 7) & 1;
		sgi = (info3 >> 7) & 1;

		status->rate_idx = mcs;
		status->flag |= RX_FLAG_HT;
		if (sgi)
			status->flag |= RX_FLAG_SHORT_GI;
		if (bw)
			status->flag |= RX_FLAG_40MHZ;
		break;
	case HTT_RX_VHT:
	case HTT_RX_VHT_WITH_TXBF:
		/* VHT-SIG-A1 in info2, VHT-SIG-A2 in info3
		   TODO check this */
		bw = info2 & 3;
		sgi = info3 & 1;
		group_id = (info2 >> 4) & 0x3F;

		if (GROUP_ID_IS_SU_MIMO(group_id)) {
			mcs = (info3 >> 4) & 0x0F;
			nss = ((info2 >> 10) & 0x07) + 1;
		} else {
			/* Hardware doesn't decode VHT-SIG-B into Rx descriptor
			 * so it's impossible to decode MCS. Also since
			 * firmware consumes Group Id Management frames host
			 * has no knowledge regarding group/user position
			 * mapping so it's impossible to pick the correct Nsts
			 * from VHT-SIG-A1.
			 *
			 * Bandwidth and SGI are valid so report the rateinfo
			 * on best-effort basis.
			 */
			mcs = 0;
			nss = 1;
		}

		if (mcs > 0x09) {
			ath10k_warn(ar, "invalid MCS received %u\n", mcs);
			ath10k_warn(ar, "rxd %08x mpdu start %08x %08x msdu start %08x %08x ppdu start %08x %08x %08x %08x %08x\n",
				    __le32_to_cpu(rxd->attention.flags),
				    __le32_to_cpu(rxd->mpdu_start.info0),
				    __le32_to_cpu(rxd->mpdu_start.info1),
				    __le32_to_cpu(rxd->msdu_start.common.info0),
				    __le32_to_cpu(rxd->msdu_start.common.info1),
				    rxd->ppdu_start.info0,
				    __le32_to_cpu(rxd->ppdu_start.info1),
				    __le32_to_cpu(rxd->ppdu_start.info2),
				    __le32_to_cpu(rxd->ppdu_start.info3),
				    __le32_to_cpu(rxd->ppdu_start.info4));

			ath10k_warn(ar, "msdu end %08x mpdu end %08x\n",
				    __le32_to_cpu(rxd->msdu_end.common.info0),
				    __le32_to_cpu(rxd->mpdu_end.info0));

			ath10k_dbg_dump(ar, ATH10K_DBG_HTT_DUMP, NULL,
					"rx desc msdu payload: ",
					rxd->msdu_payload, 50);
		}

		status->rate_idx = mcs;
		status->vht_nss = nss;

		if (sgi)
			status->flag |= RX_FLAG_SHORT_GI;

		switch (bw) {
		/* 20MHZ */
		case 0:
			break;
		/* 40MHZ */
		case 1:
			status->flag |= RX_FLAG_40MHZ;
			break;
		/* 80MHZ */
		case 2:
			status->vht_flag |= RX_VHT_FLAG_80MHZ;
		}

		status->flag |= RX_FLAG_VHT;
		break;
	default:
		break;
	}
}

static struct ieee80211_channel *
ath10k_htt_rx_h_peer_channel(struct ath10k *ar, struct htt_rx_desc *rxd)
{
	struct ath10k_peer *peer;
	struct ath10k_vif *arvif;
	struct cfg80211_chan_def def;
	u16 peer_id;

	lockdep_assert_held(&ar->data_lock);

	if (!rxd)
		return NULL;

	if (rxd->attention.flags &
	    __cpu_to_le32(RX_ATTENTION_FLAGS_PEER_IDX_INVALID))
		return NULL;

	if (!(rxd->msdu_end.common.info0 &
	      __cpu_to_le32(RX_MSDU_END_INFO0_FIRST_MSDU)))
		return NULL;

	peer_id = MS(__le32_to_cpu(rxd->mpdu_start.info0),
		     RX_MPDU_START_INFO0_PEER_IDX);

	peer = ath10k_peer_find_by_id(ar, peer_id);
	if (!peer)
		return NULL;

	arvif = ath10k_get_arvif(ar, peer->vdev_id);
	if (WARN_ON_ONCE(!arvif))
		return NULL;

	if (WARN_ON(ath10k_mac_vif_chan(arvif->vif, &def)))
		return NULL;

	return def.chan;
}

static struct ieee80211_channel *
ath10k_htt_rx_h_vdev_channel(struct ath10k *ar, u32 vdev_id)
{
	struct ath10k_vif *arvif;
	struct cfg80211_chan_def def;

	lockdep_assert_held(&ar->data_lock);

	list_for_each_entry(arvif, &ar->arvifs, list) {
		if (arvif->vdev_id == vdev_id &&
		    ath10k_mac_vif_chan(arvif->vif, &def) == 0)
			return def.chan;
	}

	return NULL;
}

static void
ath10k_htt_rx_h_any_chan_iter(struct ieee80211_hw *hw,
			      struct ieee80211_chanctx_conf *conf,
			      void *data)
{
	struct cfg80211_chan_def *def = data;

	*def = conf->def;
}

static struct ieee80211_channel *
ath10k_htt_rx_h_any_channel(struct ath10k *ar)
{
	struct cfg80211_chan_def def = {};

	ieee80211_iter_chan_contexts_atomic(ar->hw,
					    ath10k_htt_rx_h_any_chan_iter,
					    &def);

	return def.chan;
}

static bool ath10k_htt_rx_h_channel(struct ath10k *ar,
				    struct ieee80211_rx_status *status,
				    struct htt_rx_desc *rxd,
				    u32 vdev_id)
{
	struct ieee80211_channel *ch;

	spin_lock_bh(&ar->data_lock);
	ch = ar->scan_channel;
	if (!ch)
		ch = ar->rx_channel;
	if (!ch)
		ch = ath10k_htt_rx_h_peer_channel(ar, rxd);
	if (!ch)
		ch = ath10k_htt_rx_h_vdev_channel(ar, vdev_id);
	if (!ch)
		ch = ath10k_htt_rx_h_any_channel(ar);
	if (!ch)
		ch = ar->tgt_oper_chan;
	spin_unlock_bh(&ar->data_lock);

	if (!ch)
		return false;

	status->band = ch->band;
	status->freq = ch->center_freq;

	return true;
}

static void ath10k_htt_rx_h_signal(struct ath10k *ar,
				   struct ieee80211_rx_status *status,
				   struct htt_rx_desc *rxd)
{
	/* FIXME: Get real NF */
	status->signal = ATH10K_DEFAULT_NOISE_FLOOR +
			 rxd->ppdu_start.rssi_comb;
	status->flag &= ~RX_FLAG_NO_SIGNAL_VAL;
}

static void ath10k_htt_rx_h_mactime(struct ath10k *ar,
				    struct ieee80211_rx_status *status,
				    struct htt_rx_desc *rxd)
{
	/* FIXME: TSF is known only at the end of PPDU, in the last MPDU. This
	 * means all prior MSDUs in a PPDU are reported to mac80211 without the
	 * TSF. Is it worth holding frames until end of PPDU is known?
	 *
	 * FIXME: Can we get/compute 64bit TSF?
	 */
	status->mactime = __le32_to_cpu(rxd->ppdu_end.common.tsf_timestamp);
	status->flag |= RX_FLAG_MACTIME_END;
}

static void ath10k_htt_rx_h_ppdu(struct ath10k *ar,
				 struct sk_buff_head *amsdu,
				 struct ieee80211_rx_status *status,
				 u32 vdev_id)
{
	struct sk_buff *first;
	struct htt_rx_desc *rxd;
	bool is_first_ppdu;
	bool is_last_ppdu;

	if (skb_queue_empty(amsdu))
		return;

	first = skb_peek(amsdu);
	rxd = (void *)first->data - sizeof(*rxd);

	is_first_ppdu = !!(rxd->attention.flags &
			   __cpu_to_le32(RX_ATTENTION_FLAGS_FIRST_MPDU));
	is_last_ppdu = !!(rxd->attention.flags &
			  __cpu_to_le32(RX_ATTENTION_FLAGS_LAST_MPDU));

	if (is_first_ppdu) {
		/* New PPDU starts so clear out the old per-PPDU status. */
		status->freq = 0;
		status->rate_idx = 0;
		status->vht_nss = 0;
		status->vht_flag &= ~RX_VHT_FLAG_80MHZ;
		status->flag &= ~(RX_FLAG_HT |
				  RX_FLAG_VHT |
				  RX_FLAG_SHORT_GI |
				  RX_FLAG_40MHZ |
				  RX_FLAG_MACTIME_END);
		status->flag |= RX_FLAG_NO_SIGNAL_VAL;

		ath10k_htt_rx_h_signal(ar, status, rxd);
		ath10k_htt_rx_h_channel(ar, status, rxd, vdev_id);
		ath10k_htt_rx_h_rates(ar, status, rxd);
	}

	if (is_last_ppdu)
		ath10k_htt_rx_h_mactime(ar, status, rxd);
}

static const char * const tid_to_ac[] = {
	"BE",
	"BK",
	"BK",
	"BE",
	"VI",
	"VI",
	"VO",
	"VO",
};

static char *ath10k_get_tid(struct ieee80211_hdr *hdr, char *out, size_t size)
{
	u8 *qc;
	int tid;

	if (!ieee80211_is_data_qos(hdr->frame_control))
		return "";

	qc = ieee80211_get_qos_ctl(hdr);
	tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
	if (tid < 8)
		snprintf(out, size, "tid %d (%s)", tid, tid_to_ac[tid]);
	else
		snprintf(out, size, "tid %d", tid);

	return out;
}

static void ath10k_process_rx(struct ath10k *ar,
			      struct ieee80211_rx_status *rx_status,
			      struct sk_buff *skb)
{
	struct ieee80211_rx_status *status;
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
	char tid[32];

	status = IEEE80211_SKB_RXCB(skb);
	*status = *rx_status;

	ath10k_dbg(ar, ATH10K_DBG_DATA,
		   "rx skb %p len %u peer %pM %s %s sn %u %s%s%s%s%s %srate_idx %u vht_nss %u freq %u band %u flag 0x%x fcs-err %i mic-err %i amsdu-more %i\n",
		   skb,
		   skb->len,
		   ieee80211_get_SA(hdr),
		   ath10k_get_tid(hdr, tid, sizeof(tid)),
		   is_multicast_ether_addr(ieee80211_get_DA(hdr)) ?
							"mcast" : "ucast",
		   (__le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_SEQ) >> 4,
		   status->flag == 0 ? "legacy" : "",
		   status->flag & RX_FLAG_HT ? "ht" : "",
		   status->flag & RX_FLAG_VHT ? "vht" : "",
		   status->flag & RX_FLAG_40MHZ ? "40" : "",
		   status->vht_flag & RX_VHT_FLAG_80MHZ ? "80" : "",
		   status->flag & RX_FLAG_SHORT_GI ? "sgi " : "",
		   status->rate_idx,
		   status->vht_nss,
		   status->freq,
		   status->band, status->flag,
		   !!(status->flag & RX_FLAG_FAILED_FCS_CRC),
		   !!(status->flag & RX_FLAG_MMIC_ERROR),
		   !!(status->flag & RX_FLAG_AMSDU_MORE));
	ath10k_dbg_dump(ar, ATH10K_DBG_HTT_DUMP, NULL, "rx skb: ",
			skb->data, skb->len);
	trace_ath10k_rx_hdr(ar, skb->data, skb->len);
	trace_ath10k_rx_payload(ar, skb->data, skb->len);

	ieee80211_rx(ar->hw, skb);
}

static int ath10k_htt_rx_nwifi_hdrlen(struct ath10k *ar,
				      struct ieee80211_hdr *hdr)
{
	int len = ieee80211_hdrlen(hdr->frame_control);

	if (!test_bit(ATH10K_FW_FEATURE_NO_NWIFI_DECAP_4ADDR_PADDING,
		      ar->fw_features))
		len = round_up(len, 4);

	return len;
}

static void ath10k_htt_rx_h_undecap_raw(struct ath10k *ar,
					struct sk_buff *msdu,
					struct ieee80211_rx_status *status,
					enum htt_rx_mpdu_encrypt_type enctype,
					bool is_decrypted)
{
	struct ieee80211_hdr *hdr;
	struct htt_rx_desc *rxd;
	size_t hdr_len;
	size_t crypto_len;
	bool is_first;
	bool is_last;

	rxd = (void *)msdu->data - sizeof(*rxd);
	is_first = !!(rxd->msdu_end.common.info0 &
		      __cpu_to_le32(RX_MSDU_END_INFO0_FIRST_MSDU));
	is_last = !!(rxd->msdu_end.common.info0 &
		     __cpu_to_le32(RX_MSDU_END_INFO0_LAST_MSDU));

	/* Delivered decapped frame:
	 * [802.11 header]
	 * [crypto param] <-- can be trimmed if !fcs_err &&
	 *                    !decrypt_err && !peer_idx_invalid
	 * [amsdu header] <-- only if A-MSDU
	 * [rfc1042/llc]
	 * [payload]
	 * [FCS] <-- at end, needs to be trimmed
	 */

	/* This probably shouldn't happen but warn just in case */
	if (unlikely(WARN_ON_ONCE(!is_first)))
		return;

	/* This probably shouldn't happen but warn just in case */
	if (unlikely(WARN_ON_ONCE(!(is_first && is_last))))
		return;

	skb_trim(msdu, msdu->len - FCS_LEN);

	/* In most cases this will be true for sniffed frames. It makes sense
	 * to deliver them as-is without stripping the crypto param. This is
	 * necessary for software based decryption.
	 *
	 * If there's no error then the frame is decrypted. At least that is
	 * the case for frames that come in via fragmented rx indication.
	 */
	if (!is_decrypted)
		return;

	/* The payload is decrypted so strip crypto params. Start from tail
	 * since hdr is used to compute some stuff.
	 */

	hdr = (void *)msdu->data;

	/* Tail */
	if (status->flag & RX_FLAG_IV_STRIPPED)
		skb_trim(msdu, msdu->len -
			 ath10k_htt_rx_crypto_tail_len(ar, enctype));

	/* MMIC */
	if ((status->flag & RX_FLAG_MMIC_STRIPPED) &&
	    !ieee80211_has_morefrags(hdr->frame_control) &&
	    enctype == HTT_RX_MPDU_ENCRYPT_TKIP_WPA)
		skb_trim(msdu, msdu->len - 8);

	/* Head */
	if (status->flag & RX_FLAG_IV_STRIPPED) {
		hdr_len = ieee80211_hdrlen(hdr->frame_control);
		crypto_len = ath10k_htt_rx_crypto_param_len(ar, enctype);

		memmove((void *)msdu->data + crypto_len,
			(void *)msdu->data, hdr_len);
		skb_pull(msdu, crypto_len);
	}
}

static void ath10k_htt_rx_h_undecap_nwifi(struct ath10k *ar,
					  struct sk_buff *msdu,
					  struct ieee80211_rx_status *status,
					  const u8 first_hdr[64])
{
	struct ieee80211_hdr *hdr;
	size_t hdr_len;
	u8 da[ETH_ALEN];
	u8 sa[ETH_ALEN];

	/* Delivered decapped frame:
	 * [nwifi 802.11 header] <-- replaced with 802.11 hdr
	 * [rfc1042/llc]
	 *
	 * Note: The nwifi header doesn't have QoS Control and is
	 * (always?) a 3addr frame.
	 *
	 * Note2: There's no A-MSDU subframe header. Even if it's part
	 * of an A-MSDU.
	 */

	/* pull decapped header and copy SA & DA */
	if ((ar->hw_params.hw_4addr_pad == ATH10K_HW_4ADDR_PAD_BEFORE) &&
	    ieee80211_has_a4(((struct ieee80211_hdr *)first_hdr)->frame_control)) {
		/* The QCA99X0 4 address mode pad 2 bytes at the
		 * beginning of MSDU
		 */
		hdr = (struct ieee80211_hdr *)(msdu->data + 2);
		/* The skb length need be extended 2 as the 2 bytes at the tail
		 * be excluded due to the padding
		 */
		skb_put(msdu, 2);
	} else {
		hdr = (struct ieee80211_hdr *)(msdu->data);
	}

	hdr_len = ath10k_htt_rx_nwifi_hdrlen(ar, hdr);
	ether_addr_copy(da, ieee80211_get_DA(hdr));
	ether_addr_copy(sa, ieee80211_get_SA(hdr));
	skb_pull(msdu, hdr_len);

	/* push original 802.11 header */
	hdr = (struct ieee80211_hdr *)first_hdr;
	hdr_len = ieee80211_hdrlen(hdr->frame_control);
	memcpy(skb_push(msdu, hdr_len), hdr, hdr_len);

	/* original 802.11 header has a different DA and in
	 * case of 4addr it may also have different SA
	 */
	hdr = (struct ieee80211_hdr *)msdu->data;
	ether_addr_copy(ieee80211_get_DA(hdr), da);
	ether_addr_copy(ieee80211_get_SA(hdr), sa);
}

static void *ath10k_htt_rx_h_find_rfc1042(struct ath10k *ar,
					  struct sk_buff *msdu,
					  enum htt_rx_mpdu_encrypt_type enctype)
{
	struct ieee80211_hdr *hdr;
	struct htt_rx_desc *rxd;
	size_t hdr_len, crypto_len;
	void *rfc1042;
	bool is_first, is_last, is_amsdu;

	rxd = (void *)msdu->data - sizeof(*rxd);
	hdr = (void *)rxd->rx_hdr_status;

	is_first = !!(rxd->msdu_end.common.info0 &
		      __cpu_to_le32(RX_MSDU_END_INFO0_FIRST_MSDU));
	is_last = !!(rxd->msdu_end.common.info0 &
		     __cpu_to_le32(RX_MSDU_END_INFO0_LAST_MSDU));
	is_amsdu = !(is_first && is_last);

	rfc1042 = hdr;

	if (is_first) {
		hdr_len = ieee80211_hdrlen(hdr->frame_control);
		crypto_len = ath10k_htt_rx_crypto_param_len(ar, enctype);

		rfc1042 += round_up(hdr_len, 4) +
			   round_up(crypto_len, 4);
	}

	if (is_amsdu)
		rfc1042 += sizeof(struct amsdu_subframe_hdr);

	return rfc1042;
}

static void ath10k_htt_rx_h_undecap_eth(struct ath10k *ar,
					struct sk_buff *msdu,
					struct ieee80211_rx_status *status,
					const u8 first_hdr[64],
					enum htt_rx_mpdu_encrypt_type enctype)
{
	struct ieee80211_hdr *hdr;
	struct ethhdr *eth;
	size_t hdr_len;
	void *rfc1042;
	u8 da[ETH_ALEN];
	u8 sa[ETH_ALEN];

	/* Delivered decapped frame:
	 * [eth header] <-- replaced with 802.11 hdr & rfc1042/llc
	 * [payload]
	 */

	rfc1042 = ath10k_htt_rx_h_find_rfc1042(ar, msdu, enctype);
	if (WARN_ON_ONCE(!rfc1042))
		return;

	/* pull decapped header and copy SA & DA */
	eth = (struct ethhdr *)msdu->data;
	ether_addr_copy(da, eth->h_dest);
	ether_addr_copy(sa, eth->h_source);
	skb_pull(msdu, sizeof(struct ethhdr));

	/* push rfc1042/llc/snap */
	memcpy(skb_push(msdu, sizeof(struct rfc1042_hdr)), rfc1042,
	       sizeof(struct rfc1042_hdr));

	/* push original 802.11 header */
	hdr = (struct ieee80211_hdr *)first_hdr;
	hdr_len = ieee80211_hdrlen(hdr->frame_control);
	memcpy(skb_push(msdu, hdr_len), hdr, hdr_len);

	/* original 802.11 header has a different DA and in
	 * case of 4addr it may also have different SA
	 */
	hdr = (struct ieee80211_hdr *)msdu->data;
	ether_addr_copy(ieee80211_get_DA(hdr), da);
	ether_addr_copy(ieee80211_get_SA(hdr), sa);
}

static void ath10k_htt_rx_h_undecap_snap(struct ath10k *ar,
					 struct sk_buff *msdu,
					 struct ieee80211_rx_status *status,
					 const u8 first_hdr[64])
{
	struct ieee80211_hdr *hdr;
	size_t hdr_len;

	/* Delivered decapped frame:
	 * [amsdu header] <-- replaced with 802.11 hdr
	 * [rfc1042/llc]
	 * [payload]
	 */

	skb_pull(msdu, sizeof(struct amsdu_subframe_hdr));

	hdr = (struct ieee80211_hdr *)first_hdr;
	hdr_len = ieee80211_hdrlen(hdr->frame_control);
	memcpy(skb_push(msdu, hdr_len), hdr, hdr_len);
}

static void ath10k_htt_rx_h_undecap(struct ath10k *ar,
				    struct sk_buff *msdu,
				    struct ieee80211_rx_status *status,
				    u8 first_hdr[64],
				    enum htt_rx_mpdu_encrypt_type enctype,
				    bool is_decrypted)
{
	struct htt_rx_desc *rxd;
	enum rx_msdu_decap_format decap;

	/* First msdu's decapped header:
	 * [802.11 header] <-- padded to 4 bytes long
	 * [crypto param] <-- padded to 4 bytes long
	 * [amsdu header] <-- only if A-MSDU
	 * [rfc1042/llc]
	 *
	 * Other (2nd, 3rd, ..) msdu's decapped header:
	 * [amsdu header] <-- only if A-MSDU
	 * [rfc1042/llc]
	 */

	rxd = (void *)msdu->data - sizeof(*rxd);
	decap = MS(__le32_to_cpu(rxd->msdu_start.common.info1),
		   RX_MSDU_START_INFO1_DECAP_FORMAT);

	switch (decap) {
	case RX_MSDU_DECAP_RAW:
		ath10k_htt_rx_h_undecap_raw(ar, msdu, status, enctype,
					    is_decrypted);
		break;
	case RX_MSDU_DECAP_NATIVE_WIFI:
		ath10k_htt_rx_h_undecap_nwifi(ar, msdu, status, first_hdr);
		break;
	case RX_MSDU_DECAP_ETHERNET2_DIX:
		ath10k_htt_rx_h_undecap_eth(ar, msdu, status, first_hdr, enctype);
		break;
	case RX_MSDU_DECAP_8023_SNAP_LLC:
		ath10k_htt_rx_h_undecap_snap(ar, msdu, status, first_hdr);
		break;
	}
}

static int ath10k_htt_rx_get_csum_state(struct sk_buff *skb)
{
	struct htt_rx_desc *rxd;
	u32 flags, info;
	bool is_ip4, is_ip6;
	bool is_tcp, is_udp;
	bool ip_csum_ok, tcpudp_csum_ok;

	rxd = (void *)skb->data - sizeof(*rxd);
	flags = __le32_to_cpu(rxd->attention.flags);
	info = __le32_to_cpu(rxd->msdu_start.common.info1);

	is_ip4 = !!(info & RX_MSDU_START_INFO1_IPV4_PROTO);
	is_ip6 = !!(info & RX_MSDU_START_INFO1_IPV6_PROTO);
	is_tcp = !!(info & RX_MSDU_START_INFO1_TCP_PROTO);
	is_udp = !!(info & RX_MSDU_START_INFO1_UDP_PROTO);
	ip_csum_ok = !(flags & RX_ATTENTION_FLAGS_IP_CHKSUM_FAIL);
	tcpudp_csum_ok = !(flags & RX_ATTENTION_FLAGS_TCP_UDP_CHKSUM_FAIL);

	if (!is_ip4 && !is_ip6)
		return CHECKSUM_NONE;
	if (!is_tcp && !is_udp)
		return CHECKSUM_NONE;
	if (!ip_csum_ok)
		return CHECKSUM_NONE;
	if (!tcpudp_csum_ok)
		return CHECKSUM_NONE;

	return CHECKSUM_UNNECESSARY;
}

static void ath10k_htt_rx_h_csum_offload(struct sk_buff *msdu)
{
	msdu->ip_summed = ath10k_htt_rx_get_csum_state(msdu);
}

static void ath10k_htt_rx_h_mpdu(struct ath10k *ar,
				 struct sk_buff_head *amsdu,
				 struct ieee80211_rx_status *status)
{
	struct sk_buff *first;
	struct sk_buff *last;
	struct sk_buff *msdu;
	struct htt_rx_desc *rxd;
	struct ieee80211_hdr *hdr;
	enum htt_rx_mpdu_encrypt_type enctype;
	u8 first_hdr[64];
	u8 *qos;
	size_t hdr_len;
	bool has_fcs_err;
	bool has_crypto_err;
	bool has_tkip_err;
	bool has_peer_idx_invalid;
	bool is_decrypted;
	bool is_mgmt;
	u32 attention;

	if (skb_queue_empty(amsdu))
		return;

	first = skb_peek(amsdu);
	rxd = (void *)first->data - sizeof(*rxd);

	is_mgmt = !!(rxd->attention.flags &
		     __cpu_to_le32(RX_ATTENTION_FLAGS_MGMT_TYPE));

	enctype = MS(__le32_to_cpu(rxd->mpdu_start.info0),
		     RX_MPDU_START_INFO0_ENCRYPT_TYPE);

	/* First MSDU's Rx descriptor in an A-MSDU contains full 802.11
	 * decapped header. It'll be used for undecapping of each MSDU.
	 */
	hdr = (void *)rxd->rx_hdr_status;
	hdr_len = ieee80211_hdrlen(hdr->frame_control);
	memcpy(first_hdr, hdr, hdr_len);

	/* Each A-MSDU subframe will use the original header as the base and be
	 * reported as a separate MSDU so strip the A-MSDU bit from QoS Ctl.
	 */
	hdr = (void *)first_hdr;
	qos = ieee80211_get_qos_ctl(hdr);
	qos[0] &= ~IEEE80211_QOS_CTL_A_MSDU_PRESENT;

	/* Some attention flags are valid only in the last MSDU. */
	last = skb_peek_tail(amsdu);
	rxd = (void *)last->data - sizeof(*rxd);
	attention = __le32_to_cpu(rxd->attention.flags);

	has_fcs_err = !!(attention & RX_ATTENTION_FLAGS_FCS_ERR);
	has_crypto_err = !!(attention & RX_ATTENTION_FLAGS_DECRYPT_ERR);
	has_tkip_err = !!(attention & RX_ATTENTION_FLAGS_TKIP_MIC_ERR);
	has_peer_idx_invalid = !!(attention & RX_ATTENTION_FLAGS_PEER_IDX_INVALID);

	/* Note: If hardware captures an encrypted frame that it can't decrypt,
	 * e.g. due to fcs error, missing peer or invalid key data it will
	 * report the frame as raw.
	 */
	is_decrypted = (enctype != HTT_RX_MPDU_ENCRYPT_NONE &&
			!has_fcs_err &&
			!has_crypto_err &&
			!has_peer_idx_invalid);

	/* Clear per-MPDU flags while leaving per-PPDU flags intact. */
	status->flag &= ~(RX_FLAG_FAILED_FCS_CRC |
			  RX_FLAG_MMIC_ERROR |
			  RX_FLAG_DECRYPTED |
			  RX_FLAG_IV_STRIPPED |
			  RX_FLAG_ONLY_MONITOR |
			  RX_FLAG_MMIC_STRIPPED);

	if (has_fcs_err)
		status->flag |= RX_FLAG_FAILED_FCS_CRC;

	if (has_tkip_err)
		status->flag |= RX_FLAG_MMIC_ERROR;

	/* Firmware reports all necessary management frames via WMI already.
	 * They are not reported to monitor interfaces at all so pass the ones
	 * coming via HTT to monitor interfaces instead. This simplifies
	 * matters a lot.
	 */
	if (is_mgmt)
		status->flag |= RX_FLAG_ONLY_MONITOR;

	if (is_decrypted) {
		status->flag |= RX_FLAG_DECRYPTED;

		if (likely(!is_mgmt))
			status->flag |= RX_FLAG_IV_STRIPPED |
					RX_FLAG_MMIC_STRIPPED;
}

	skb_queue_walk(amsdu, msdu) {
		ath10k_htt_rx_h_csum_offload(msdu);
		ath10k_htt_rx_h_undecap(ar, msdu, status, first_hdr, enctype,
					is_decrypted);

		/* Undecapping involves copying the original 802.11 header back
		 * to sk_buff. If frame is protected and hardware has decrypted
		 * it then remove the protected bit.
		 */
		if (!is_decrypted)
			continue;
		if (is_mgmt)
			continue;

		hdr = (void *)msdu->data;
		hdr->frame_control &= ~__cpu_to_le16(IEEE80211_FCTL_PROTECTED);
	}
}

static void ath10k_htt_rx_h_deliver(struct ath10k *ar,
				    struct sk_buff_head *amsdu,
				    struct ieee80211_rx_status *status)
{
	struct sk_buff *msdu;

	while ((msdu = __skb_dequeue(amsdu))) {
		/* Setup per-MSDU flags */
		if (skb_queue_empty(amsdu))
			status->flag &= ~RX_FLAG_AMSDU_MORE;
		else
			status->flag |= RX_FLAG_AMSDU_MORE;

		ath10k_process_rx(ar, status, msdu);
	}
}

static int ath10k_unchain_msdu(struct sk_buff_head *amsdu)
{
	struct sk_buff *skb, *first;
	int space;
	int total_len = 0;

	/* TODO:  Might could optimize this by using
	 * skb_try_coalesce or similar method to
	 * decrease copying, or maybe get mac80211 to
	 * provide a way to just receive a list of
	 * skb?
	 */

	first = __skb_dequeue(amsdu);

	/* Allocate total length all at once. */
	skb_queue_walk(amsdu, skb)
		total_len += skb->len;

	space = total_len - skb_tailroom(first);
	if ((space > 0) &&
	    (pskb_expand_head(first, 0, space, GFP_ATOMIC) < 0)) {
		/* TODO:  bump some rx-oom error stat */
		/* put it back together so we can free the
		 * whole list at once.
		 */
		__skb_queue_head(amsdu, first);
		return -1;
	}

	/* Walk list again, copying contents into
	 * msdu_head
	 */
	while ((skb = __skb_dequeue(amsdu))) {
		skb_copy_from_linear_data(skb, skb_put(first, skb->len),
					  skb->len);
		dev_kfree_skb_any(skb);
	}

	__skb_queue_head(amsdu, first);
	return 0;
}

static void ath10k_htt_rx_h_unchain(struct ath10k *ar,
				    struct sk_buff_head *amsdu,
				    bool chained)
{
	struct sk_buff *first;
	struct htt_rx_desc *rxd;
	enum rx_msdu_decap_format decap;

	first = skb_peek(amsdu);
	rxd = (void *)first->data - sizeof(*rxd);
	decap = MS(__le32_to_cpu(rxd->msdu_start.common.info1),
		   RX_MSDU_START_INFO1_DECAP_FORMAT);

	if (!chained)
		return;

	/* FIXME: Current unchaining logic can only handle simple case of raw
	 * msdu chaining. If decapping is other than raw the chaining may be
	 * more complex and this isn't handled by the current code. Don't even
	 * try re-constructing such frames - it'll be pretty much garbage.
	 */
	if (decap != RX_MSDU_DECAP_RAW ||
	    skb_queue_len(amsdu) != 1 + rxd->frag_info.ring2_more_count) {
		__skb_queue_purge(amsdu);
		return;
	}

	ath10k_unchain_msdu(amsdu);
}

static bool ath10k_htt_rx_amsdu_allowed(struct ath10k *ar,
					struct sk_buff_head *amsdu,
					struct ieee80211_rx_status *rx_status)
{
	/* FIXME: It might be a good idea to do some fuzzy-testing to drop
	 * invalid/dangerous frames.
	 */

	if (!rx_status->freq) {
		ath10k_warn(ar, "no channel configured; ignoring frame(s)!\n");
		return false;
	}

	if (test_bit(ATH10K_CAC_RUNNING, &ar->dev_flags)) {
		ath10k_dbg(ar, ATH10K_DBG_HTT, "htt rx cac running\n");
		return false;
	}

	return true;
}

static void ath10k_htt_rx_h_filter(struct ath10k *ar,
				   struct sk_buff_head *amsdu,
				   struct ieee80211_rx_status *rx_status)
{
	if (skb_queue_empty(amsdu))
		return;

	if (ath10k_htt_rx_amsdu_allowed(ar, amsdu, rx_status))
		return;

	__skb_queue_purge(amsdu);
}

static int ath10k_htt_rx_handle_amsdu(struct ath10k_htt *htt)
{
	struct ath10k *ar = htt->ar;
	static struct ieee80211_rx_status rx_status;
	struct sk_buff_head amsdu;
	int ret;

	__skb_queue_head_init(&amsdu);

	spin_lock_bh(&htt->rx_ring.lock);
	if (htt->rx_confused) {
		spin_unlock_bh(&htt->rx_ring.lock);
		return -EIO;
	}
	ret = ath10k_htt_rx_amsdu_pop(htt, &amsdu);
	spin_unlock_bh(&htt->rx_ring.lock);

	if (ret < 0) {
		ath10k_warn(ar, "rx ring became corrupted: %d\n", ret);
		__skb_queue_purge(&amsdu);
		/* FIXME: It's probably a good idea to reboot the
		 * device instead of leaving it inoperable.
		 */
		htt->rx_confused = true;
		return ret;
	}

	ath10k_htt_rx_h_ppdu(ar, &amsdu, &rx_status, 0xffff);
	ath10k_htt_rx_h_unchain(ar, &amsdu, ret > 0);
	ath10k_htt_rx_h_filter(ar, &amsdu, &rx_status);
	ath10k_htt_rx_h_mpdu(ar, &amsdu, &rx_status);
	ath10k_htt_rx_h_deliver(ar, &amsdu, &rx_status);

	return 0;
}

static void ath10k_htt_rx_proc_rx_ind(struct ath10k_htt *htt,
				      struct htt_rx_indication *rx)
{
	struct ath10k *ar = htt->ar;
	struct htt_rx_indication_mpdu_range *mpdu_ranges;
	int num_mpdu_ranges;
	int i, mpdu_count = 0;

	num_mpdu_ranges = MS(__le32_to_cpu(rx->hdr.info1),
			     HTT_RX_INDICATION_INFO1_NUM_MPDU_RANGES);
	mpdu_ranges = htt_rx_ind_get_mpdu_ranges(rx);

	ath10k_dbg_dump(ar, ATH10K_DBG_HTT_DUMP, NULL, "htt rx ind: ",
			rx, sizeof(*rx) +
			(sizeof(struct htt_rx_indication_mpdu_range) *
				num_mpdu_ranges));

	for (i = 0; i < num_mpdu_ranges; i++)
		mpdu_count += mpdu_ranges[i].mpdu_count;

	atomic_add(mpdu_count, &htt->num_mpdus_ready);

	tasklet_schedule(&htt->txrx_compl_task);
}

static void ath10k_htt_rx_frag_handler(struct ath10k_htt *htt)
{
	atomic_inc(&htt->num_mpdus_ready);

	tasklet_schedule(&htt->txrx_compl_task);
}

static void ath10k_htt_rx_tx_compl_ind(struct ath10k *ar,
				       struct sk_buff *skb)
{
	struct ath10k_htt *htt = &ar->htt;
	struct htt_resp *resp = (struct htt_resp *)skb->data;
	struct htt_tx_done tx_done = {};
	int status = MS(resp->data_tx_completion.flags, HTT_DATA_TX_STATUS);
	__le16 msdu_id;
	int i;

	switch (status) {
	case HTT_DATA_TX_STATUS_NO_ACK:
		tx_done.status = HTT_TX_COMPL_STATE_NOACK;
		break;
	case HTT_DATA_TX_STATUS_OK:
		tx_done.status = HTT_TX_COMPL_STATE_ACK;
		break;
	case HTT_DATA_TX_STATUS_DISCARD:
	case HTT_DATA_TX_STATUS_POSTPONE:
	case HTT_DATA_TX_STATUS_DOWNLOAD_FAIL:
		tx_done.status = HTT_TX_COMPL_STATE_DISCARD;
		break;
	default:
		ath10k_warn(ar, "unhandled tx completion status %d\n", status);
		tx_done.status = HTT_TX_COMPL_STATE_DISCARD;
		break;
	}

	ath10k_dbg(ar, ATH10K_DBG_HTT, "htt tx completion num_msdus %d\n",
		   resp->data_tx_completion.num_msdus);

	for (i = 0; i < resp->data_tx_completion.num_msdus; i++) {
		msdu_id = resp->data_tx_completion.msdus[i];
		tx_done.msdu_id = __le16_to_cpu(msdu_id);

		/* kfifo_put: In practice firmware shouldn't fire off per-CE
		 * interrupt and main interrupt (MSI/-X range case) for the same
		 * HTC service so it should be safe to use kfifo_put w/o lock.
		 *
		 * From kfifo_put() documentation:
		 *  Note that with only one concurrent reader and one concurrent
		 *  writer, you don't need extra locking to use these macro.
		 */
		if (!kfifo_put(&htt->txdone_fifo, tx_done)) {
			ath10k_warn(ar, "txdone fifo overrun, msdu_id %d status %d\n",
				    tx_done.msdu_id, tx_done.status);
			ath10k_txrx_tx_unref(htt, &tx_done);
		}
	}
}

static void ath10k_htt_rx_addba(struct ath10k *ar, struct htt_resp *resp)
{
	struct htt_rx_addba *ev = &resp->rx_addba;
	struct ath10k_peer *peer;
	struct ath10k_vif *arvif;
	u16 info0, tid, peer_id;

	info0 = __le16_to_cpu(ev->info0);
	tid = MS(info0, HTT_RX_BA_INFO0_TID);
	peer_id = MS(info0, HTT_RX_BA_INFO0_PEER_ID);

	ath10k_dbg(ar, ATH10K_DBG_HTT,
		   "htt rx addba tid %hu peer_id %hu size %hhu\n",
		   tid, peer_id, ev->window_size);

	spin_lock_bh(&ar->data_lock);
	peer = ath10k_peer_find_by_id(ar, peer_id);
	if (!peer) {
		ath10k_warn(ar, "received addba event for invalid peer_id: %hu\n",
			    peer_id);
		spin_unlock_bh(&ar->data_lock);
		return;
	}

	arvif = ath10k_get_arvif(ar, peer->vdev_id);
	if (!arvif) {
		ath10k_warn(ar, "received addba event for invalid vdev_id: %u\n",
			    peer->vdev_id);
		spin_unlock_bh(&ar->data_lock);
		return;
	}

	ath10k_dbg(ar, ATH10K_DBG_HTT,
		   "htt rx start rx ba session sta %pM tid %hu size %hhu\n",
		   peer->addr, tid, ev->window_size);

	ieee80211_start_rx_ba_session_offl(arvif->vif, peer->addr, tid);
	spin_unlock_bh(&ar->data_lock);
}

static void ath10k_htt_rx_delba(struct ath10k *ar, struct htt_resp *resp)
{
	struct htt_rx_delba *ev = &resp->rx_delba;
	struct ath10k_peer *peer;
	struct ath10k_vif *arvif;
	u16 info0, tid, peer_id;

	info0 = __le16_to_cpu(ev->info0);
	tid = MS(info0, HTT_RX_BA_INFO0_TID);
	peer_id = MS(info0, HTT_RX_BA_INFO0_PEER_ID);

	ath10k_dbg(ar, ATH10K_DBG_HTT,
		   "htt rx delba tid %hu peer_id %hu\n",
		   tid, peer_id);

	spin_lock_bh(&ar->data_lock);
	peer = ath10k_peer_find_by_id(ar, peer_id);
	if (!peer) {
		ath10k_warn(ar, "received addba event for invalid peer_id: %hu\n",
			    peer_id);
		spin_unlock_bh(&ar->data_lock);
		return;
	}

	arvif = ath10k_get_arvif(ar, peer->vdev_id);
	if (!arvif) {
		ath10k_warn(ar, "received addba event for invalid vdev_id: %u\n",
			    peer->vdev_id);
		spin_unlock_bh(&ar->data_lock);
		return;
	}

	ath10k_dbg(ar, ATH10K_DBG_HTT,
		   "htt rx stop rx ba session sta %pM tid %hu\n",
		   peer->addr, tid);

	ieee80211_stop_rx_ba_session_offl(arvif->vif, peer->addr, tid);
	spin_unlock_bh(&ar->data_lock);
}

static int ath10k_htt_rx_extract_amsdu(struct sk_buff_head *list,
				       struct sk_buff_head *amsdu)
{
	struct sk_buff *msdu;
	struct htt_rx_desc *rxd;

	if (skb_queue_empty(list))
		return -ENOBUFS;

	if (WARN_ON(!skb_queue_empty(amsdu)))
		return -EINVAL;

	while ((msdu = __skb_dequeue(list))) {
		__skb_queue_tail(amsdu, msdu);

		rxd = (void *)msdu->data - sizeof(*rxd);
		if (rxd->msdu_end.common.info0 &
		    __cpu_to_le32(RX_MSDU_END_INFO0_LAST_MSDU))
			break;
	}

	msdu = skb_peek_tail(amsdu);
	rxd = (void *)msdu->data - sizeof(*rxd);
	if (!(rxd->msdu_end.common.info0 &
	      __cpu_to_le32(RX_MSDU_END_INFO0_LAST_MSDU))) {
		skb_queue_splice_init(amsdu, list);
		return -EAGAIN;
	}

	return 0;
}

static void ath10k_htt_rx_h_rx_offload_prot(struct ieee80211_rx_status *status,
					    struct sk_buff *skb)
{
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;

	if (!ieee80211_has_protected(hdr->frame_control))
		return;

	/* Offloaded frames are already decrypted but firmware insists they are
	 * protected in the 802.11 header. Strip the flag.  Otherwise mac80211
	 * will drop the frame.
	 */

	hdr->frame_control &= ~__cpu_to_le16(IEEE80211_FCTL_PROTECTED);
	status->flag |= RX_FLAG_DECRYPTED |
			RX_FLAG_IV_STRIPPED |
			RX_FLAG_MMIC_STRIPPED;
}

static void ath10k_htt_rx_h_rx_offload(struct ath10k *ar,
				       struct sk_buff_head *list)
{
	struct ath10k_htt *htt = &ar->htt;
	struct ieee80211_rx_status *status = &htt->rx_status;
	struct htt_rx_offload_msdu *rx;
	struct sk_buff *msdu;
	size_t offset;

	while ((msdu = __skb_dequeue(list))) {
		/* Offloaded frames don't have Rx descriptor. Instead they have
		 * a short meta information header.
		 */

		rx = (void *)msdu->data;

		skb_put(msdu, sizeof(*rx));
		skb_pull(msdu, sizeof(*rx));

		if (skb_tailroom(msdu) < __le16_to_cpu(rx->msdu_len)) {
			ath10k_warn(ar, "dropping frame: offloaded rx msdu is too long!\n");
			dev_kfree_skb_any(msdu);
			continue;
		}

		skb_put(msdu, __le16_to_cpu(rx->msdu_len));

		/* Offloaded rx header length isn't multiple of 2 nor 4 so the
		 * actual payload is unaligned. Align the frame.  Otherwise
		 * mac80211 complains.  This shouldn't reduce performance much
		 * because these offloaded frames are rare.
		 */
		offset = 4 - ((unsigned long)msdu->data & 3);
		skb_put(msdu, offset);
		memmove(msdu->data + offset, msdu->data, msdu->len);
		skb_pull(msdu, offset);

		/* FIXME: The frame is NWifi. Re-construct QoS Control
		 * if possible later.
		 */

		memset(status, 0, sizeof(*status));
		status->flag |= RX_FLAG_NO_SIGNAL_VAL;

		ath10k_htt_rx_h_rx_offload_prot(status, msdu);
		ath10k_htt_rx_h_channel(ar, status, NULL, rx->vdev_id);
		ath10k_process_rx(ar, status, msdu);
	}
}

static void ath10k_htt_rx_in_ord_ind(struct ath10k *ar, struct sk_buff *skb)
{
	struct ath10k_htt *htt = &ar->htt;
	struct htt_resp *resp = (void *)skb->data;
	struct ieee80211_rx_status *status = &htt->rx_status;
	struct sk_buff_head list;
	struct sk_buff_head amsdu;
	u16 peer_id;
	u16 msdu_count;
	u8 vdev_id;
	u8 tid;
	bool offload;
	bool frag;
	int ret;

	lockdep_assert_held(&htt->rx_ring.lock);

	if (htt->rx_confused)
		return;

	skb_pull(skb, sizeof(resp->hdr));
	skb_pull(skb, sizeof(resp->rx_in_ord_ind));

	peer_id = __le16_to_cpu(resp->rx_in_ord_ind.peer_id);
	msdu_count = __le16_to_cpu(resp->rx_in_ord_ind.msdu_count);
	vdev_id = resp->rx_in_ord_ind.vdev_id;
	tid = SM(resp->rx_in_ord_ind.info, HTT_RX_IN_ORD_IND_INFO_TID);
	offload = !!(resp->rx_in_ord_ind.info &
			HTT_RX_IN_ORD_IND_INFO_OFFLOAD_MASK);
	frag = !!(resp->rx_in_ord_ind.info & HTT_RX_IN_ORD_IND_INFO_FRAG_MASK);

	ath10k_dbg(ar, ATH10K_DBG_HTT,
		   "htt rx in ord vdev %i peer %i tid %i offload %i frag %i msdu count %i\n",
		   vdev_id, peer_id, tid, offload, frag, msdu_count);

	if (skb->len < msdu_count * sizeof(*resp->rx_in_ord_ind.msdu_descs)) {
		ath10k_warn(ar, "dropping invalid in order rx indication\n");
		return;
	}

	/* The event can deliver more than 1 A-MSDU. Each A-MSDU is later
	 * extracted and processed.
	 */
	__skb_queue_head_init(&list);
	ret = ath10k_htt_rx_pop_paddr_list(htt, &resp->rx_in_ord_ind, &list);
	if (ret < 0) {
		ath10k_warn(ar, "failed to pop paddr list: %d\n", ret);
		htt->rx_confused = true;
		return;
	}

	/* Offloaded frames are very different and need to be handled
	 * separately.
	 */
	if (offload)
		ath10k_htt_rx_h_rx_offload(ar, &list);

	while (!skb_queue_empty(&list)) {
		__skb_queue_head_init(&amsdu);
		ret = ath10k_htt_rx_extract_amsdu(&list, &amsdu);
		switch (ret) {
		case 0:
			/* Note: The in-order indication may report interleaved
			 * frames from different PPDUs meaning reported rx rate
			 * to mac80211 isn't accurate/reliable. It's still
			 * better to report something than nothing though. This
			 * should still give an idea about rx rate to the user.
			 */
			ath10k_htt_rx_h_ppdu(ar, &amsdu, status, vdev_id);
			ath10k_htt_rx_h_filter(ar, &amsdu, status);
			ath10k_htt_rx_h_mpdu(ar, &amsdu, status);
			ath10k_htt_rx_h_deliver(ar, &amsdu, status);
			break;
		case -EAGAIN:
			/* fall through */
		default:
			/* Should not happen. */
			ath10k_warn(ar, "failed to extract amsdu: %d\n", ret);
			htt->rx_confused = true;
			__skb_queue_purge(&list);
			return;
		}
	}

	tasklet_schedule(&htt->rx_replenish_task);
}

static void ath10k_htt_rx_tx_fetch_resp_id_confirm(struct ath10k *ar,
						   const __le32 *resp_ids,
						   int num_resp_ids)
{
	int i;
	u32 resp_id;

	ath10k_dbg(ar, ATH10K_DBG_HTT, "htt rx tx fetch confirm num_resp_ids %d\n",
		   num_resp_ids);

	for (i = 0; i < num_resp_ids; i++) {
		resp_id = le32_to_cpu(resp_ids[i]);

		ath10k_dbg(ar, ATH10K_DBG_HTT, "htt rx tx fetch confirm resp_id %u\n",
			   resp_id);

		/* TODO: free resp_id */
	}
}

static void ath10k_htt_rx_tx_fetch_ind(struct ath10k *ar, struct sk_buff *skb)
{
	struct ieee80211_hw *hw = ar->hw;
	struct ieee80211_txq *txq;
	struct htt_resp *resp = (struct htt_resp *)skb->data;
	struct htt_tx_fetch_record *record;
	size_t len;
	size_t max_num_bytes;
	size_t max_num_msdus;
	size_t num_bytes;
	size_t num_msdus;
	const __le32 *resp_ids;
	u16 num_records;
	u16 num_resp_ids;
	u16 peer_id;
	u8 tid;
	int ret;
	int i;

	ath10k_dbg(ar, ATH10K_DBG_HTT, "htt rx tx fetch ind\n");

	len = sizeof(resp->hdr) + sizeof(resp->tx_fetch_ind);
	if (unlikely(skb->len < len)) {
		ath10k_warn(ar, "received corrupted tx_fetch_ind event: buffer too short\n");
		return;
	}

	num_records = le16_to_cpu(resp->tx_fetch_ind.num_records);
	num_resp_ids = le16_to_cpu(resp->tx_fetch_ind.num_resp_ids);

	len += sizeof(resp->tx_fetch_ind.records[0]) * num_records;
	len += sizeof(resp->tx_fetch_ind.resp_ids[0]) * num_resp_ids;

	if (unlikely(skb->len < len)) {
		ath10k_warn(ar, "received corrupted tx_fetch_ind event: too many records/resp_ids\n");
		return;
	}

	ath10k_dbg(ar, ATH10K_DBG_HTT, "htt rx tx fetch ind num records %hu num resps %hu seq %hu\n",
		   num_records, num_resp_ids,
		   le16_to_cpu(resp->tx_fetch_ind.fetch_seq_num));

	if (!ar->htt.tx_q_state.enabled) {
		ath10k_warn(ar, "received unexpected tx_fetch_ind event: not enabled\n");
		return;
	}

	if (ar->htt.tx_q_state.mode == HTT_TX_MODE_SWITCH_PUSH) {
		ath10k_warn(ar, "received unexpected tx_fetch_ind event: in push mode\n");
		return;
	}

	rcu_read_lock();

	for (i = 0; i < num_records; i++) {
		record = &resp->tx_fetch_ind.records[i];
		peer_id = MS(le16_to_cpu(record->info),
			     HTT_TX_FETCH_RECORD_INFO_PEER_ID);
		tid = MS(le16_to_cpu(record->info),
			 HTT_TX_FETCH_RECORD_INFO_TID);
		max_num_msdus = le16_to_cpu(record->num_msdus);
		max_num_bytes = le32_to_cpu(record->num_bytes);

		ath10k_dbg(ar, ATH10K_DBG_HTT, "htt rx tx fetch record %i peer_id %hu tid %hhu msdus %zu bytes %zu\n",
			   i, peer_id, tid, max_num_msdus, max_num_bytes);

		if (unlikely(peer_id >= ar->htt.tx_q_state.num_peers) ||
		    unlikely(tid >= ar->htt.tx_q_state.num_tids)) {
			ath10k_warn(ar, "received out of range peer_id %hu tid %hhu\n",
				    peer_id, tid);
			continue;
		}

		spin_lock_bh(&ar->data_lock);
		txq = ath10k_mac_txq_lookup(ar, peer_id, tid);
		spin_unlock_bh(&ar->data_lock);

		/* It is okay to release the lock and use txq because RCU read
		 * lock is held.
		 */

		if (unlikely(!txq)) {
			ath10k_warn(ar, "failed to lookup txq for peer_id %hu tid %hhu\n",
				    peer_id, tid);
			continue;
		}

		num_msdus = 0;
		num_bytes = 0;

		while (num_msdus < max_num_msdus &&
		       num_bytes < max_num_bytes) {
			ret = ath10k_mac_tx_push_txq(hw, txq);
			if (ret < 0)
				break;

			num_msdus++;
			num_bytes += ret;
		}

		record->num_msdus = cpu_to_le16(num_msdus);
		record->num_bytes = cpu_to_le32(num_bytes);

		ath10k_htt_tx_txq_recalc(hw, txq);
	}

	rcu_read_unlock();

	resp_ids = ath10k_htt_get_tx_fetch_ind_resp_ids(&resp->tx_fetch_ind);
	ath10k_htt_rx_tx_fetch_resp_id_confirm(ar, resp_ids, num_resp_ids);

	ret = ath10k_htt_tx_fetch_resp(ar,
				       resp->tx_fetch_ind.token,
				       resp->tx_fetch_ind.fetch_seq_num,
				       resp->tx_fetch_ind.records,
				       num_records);
	if (unlikely(ret)) {
		ath10k_warn(ar, "failed to submit tx fetch resp for token 0x%08x: %d\n",
			    le32_to_cpu(resp->tx_fetch_ind.token), ret);
		/* FIXME: request fw restart */
	}

	ath10k_htt_tx_txq_sync(ar);
}

static void ath10k_htt_rx_tx_fetch_confirm(struct ath10k *ar,
					   struct sk_buff *skb)
{
	const struct htt_resp *resp = (void *)skb->data;
	size_t len;
	int num_resp_ids;

	ath10k_dbg(ar, ATH10K_DBG_HTT, "htt rx tx fetch confirm\n");

	len = sizeof(resp->hdr) + sizeof(resp->tx_fetch_confirm);
	if (unlikely(skb->len < len)) {
		ath10k_warn(ar, "received corrupted tx_fetch_confirm event: buffer too short\n");
		return;
	}

	num_resp_ids = le16_to_cpu(resp->tx_fetch_confirm.num_resp_ids);
	len += sizeof(resp->tx_fetch_confirm.resp_ids[0]) * num_resp_ids;

	if (unlikely(skb->len < len)) {
		ath10k_warn(ar, "received corrupted tx_fetch_confirm event: resp_ids buffer overflow\n");
		return;
	}

	ath10k_htt_rx_tx_fetch_resp_id_confirm(ar,
					       resp->tx_fetch_confirm.resp_ids,
					       num_resp_ids);
}

static void ath10k_htt_rx_tx_mode_switch_ind(struct ath10k *ar,
					     struct sk_buff *skb)
{
	const struct htt_resp *resp = (void *)skb->data;
	const struct htt_tx_mode_switch_record *record;
	struct ieee80211_txq *txq;
	struct ath10k_txq *artxq;
	size_t len;
	size_t num_records;
	enum htt_tx_mode_switch_mode mode;
	bool enable;
	u16 info0;
	u16 info1;
	u16 threshold;
	u16 peer_id;
	u8 tid;
	int i;

	ath10k_dbg(ar, ATH10K_DBG_HTT, "htt rx tx mode switch ind\n");

	len = sizeof(resp->hdr) + sizeof(resp->tx_mode_switch_ind);
	if (unlikely(skb->len < len)) {
		ath10k_warn(ar, "received corrupted tx_mode_switch_ind event: buffer too short\n");
		return;
	}

	info0 = le16_to_cpu(resp->tx_mode_switch_ind.info0);
	info1 = le16_to_cpu(resp->tx_mode_switch_ind.info1);

	enable = !!(info0 & HTT_TX_MODE_SWITCH_IND_INFO0_ENABLE);
	num_records = MS(info0, HTT_TX_MODE_SWITCH_IND_INFO1_THRESHOLD);
	mode = MS(info1, HTT_TX_MODE_SWITCH_IND_INFO1_MODE);
	threshold = MS(info1, HTT_TX_MODE_SWITCH_IND_INFO1_THRESHOLD);

	ath10k_dbg(ar, ATH10K_DBG_HTT,
		   "htt rx tx mode switch ind info0 0x%04hx info1 0x%04hx enable %d num records %zd mode %d threshold %hu\n",
		   info0, info1, enable, num_records, mode, threshold);

	len += sizeof(resp->tx_mode_switch_ind.records[0]) * num_records;

	if (unlikely(skb->len < len)) {
		ath10k_warn(ar, "received corrupted tx_mode_switch_mode_ind event: too many records\n");
		return;
	}

	switch (mode) {
	case HTT_TX_MODE_SWITCH_PUSH:
	case HTT_TX_MODE_SWITCH_PUSH_PULL:
		break;
	default:
		ath10k_warn(ar, "received invalid tx_mode_switch_mode_ind mode %d, ignoring\n",
			    mode);
		return;
	}

	if (!enable)
		return;

	ar->htt.tx_q_state.enabled = enable;
	ar->htt.tx_q_state.mode = mode;
	ar->htt.tx_q_state.num_push_allowed = threshold;

	rcu_read_lock();

	for (i = 0; i < num_records; i++) {
		record = &resp->tx_mode_switch_ind.records[i];
		info0 = le16_to_cpu(record->info0);
		peer_id = MS(info0, HTT_TX_MODE_SWITCH_RECORD_INFO0_PEER_ID);
		tid = MS(info0, HTT_TX_MODE_SWITCH_RECORD_INFO0_TID);

		if (unlikely(peer_id >= ar->htt.tx_q_state.num_peers) ||
		    unlikely(tid >= ar->htt.tx_q_state.num_tids)) {
			ath10k_warn(ar, "received out of range peer_id %hu tid %hhu\n",
				    peer_id, tid);
			continue;
		}

		spin_lock_bh(&ar->data_lock);
		txq = ath10k_mac_txq_lookup(ar, peer_id, tid);
		spin_unlock_bh(&ar->data_lock);

		/* It is okay to release the lock and use txq because RCU read
		 * lock is held.
		 */

		if (unlikely(!txq)) {
			ath10k_warn(ar, "failed to lookup txq for peer_id %hu tid %hhu\n",
				    peer_id, tid);
			continue;
		}

		spin_lock_bh(&ar->htt.tx_lock);
		artxq = (void *)txq->drv_priv;
		artxq->num_push_allowed = le16_to_cpu(record->num_max_msdus);
		spin_unlock_bh(&ar->htt.tx_lock);
	}

	rcu_read_unlock();

	ath10k_mac_tx_push_pending(ar);
}

static inline enum ieee80211_band phy_mode_to_band(u32 phy_mode)
{
	enum ieee80211_band band;

	switch (phy_mode) {
	case MODE_11A:
	case MODE_11NA_HT20:
	case MODE_11NA_HT40:
	case MODE_11AC_VHT20:
	case MODE_11AC_VHT40:
	case MODE_11AC_VHT80:
		band = IEEE80211_BAND_5GHZ;
		break;
	case MODE_11G:
	case MODE_11B:
	case MODE_11GONLY:
	case MODE_11NG_HT20:
	case MODE_11NG_HT40:
	case MODE_11AC_VHT20_2G:
	case MODE_11AC_VHT40_2G:
	case MODE_11AC_VHT80_2G:
	default:
		band = IEEE80211_BAND_2GHZ;
	}

	return band;
}

void ath10k_htt_htc_t2h_msg_handler(struct ath10k *ar, struct sk_buff *skb)
{
	bool release;

	release = ath10k_htt_t2h_msg_handler(ar, skb);

	/* Free the indication buffer */
	if (release)
		dev_kfree_skb_any(skb);
}

bool ath10k_htt_t2h_msg_handler(struct ath10k *ar, struct sk_buff *skb)
{
	struct ath10k_htt *htt = &ar->htt;
	struct htt_resp *resp = (struct htt_resp *)skb->data;
	enum htt_t2h_msg_type type;

	/* confirm alignment */
	if (!IS_ALIGNED((unsigned long)skb->data, 4))
		ath10k_warn(ar, "unaligned htt message, expect trouble\n");

	ath10k_dbg(ar, ATH10K_DBG_HTT, "htt rx, msg_type: 0x%0X\n",
		   resp->hdr.msg_type);

	if (resp->hdr.msg_type >= ar->htt.t2h_msg_types_max) {
		ath10k_dbg(ar, ATH10K_DBG_HTT, "htt rx, unsupported msg_type: 0x%0X\n max: 0x%0X",
			   resp->hdr.msg_type, ar->htt.t2h_msg_types_max);
		return true;
	}
	type = ar->htt.t2h_msg_types[resp->hdr.msg_type];

	switch (type) {
	case HTT_T2H_MSG_TYPE_VERSION_CONF: {
		htt->target_version_major = resp->ver_resp.major;
		htt->target_version_minor = resp->ver_resp.minor;
		complete(&htt->target_version_received);
		break;
	}
	case HTT_T2H_MSG_TYPE_RX_IND:
		ath10k_htt_rx_proc_rx_ind(htt, &resp->rx_ind);
		break;
	case HTT_T2H_MSG_TYPE_PEER_MAP: {
		struct htt_peer_map_event ev = {
			.vdev_id = resp->peer_map.vdev_id,
			.peer_id = __le16_to_cpu(resp->peer_map.peer_id),
		};
		memcpy(ev.addr, resp->peer_map.addr, sizeof(ev.addr));
		ath10k_peer_map_event(htt, &ev);
		break;
	}
	case HTT_T2H_MSG_TYPE_PEER_UNMAP: {
		struct htt_peer_unmap_event ev = {
			.peer_id = __le16_to_cpu(resp->peer_unmap.peer_id),
		};
		ath10k_peer_unmap_event(htt, &ev);
		break;
	}
	case HTT_T2H_MSG_TYPE_MGMT_TX_COMPLETION: {
		struct htt_tx_done tx_done = {};
		int status = __le32_to_cpu(resp->mgmt_tx_completion.status);

		tx_done.msdu_id = __le32_to_cpu(resp->mgmt_tx_completion.desc_id);

		switch (status) {
		case HTT_MGMT_TX_STATUS_OK:
			tx_done.status = HTT_TX_COMPL_STATE_ACK;
			break;
		case HTT_MGMT_TX_STATUS_RETRY:
			tx_done.status = HTT_TX_COMPL_STATE_NOACK;
			break;
		case HTT_MGMT_TX_STATUS_DROP:
			tx_done.status = HTT_TX_COMPL_STATE_DISCARD;
			break;
		}

		status = ath10k_txrx_tx_unref(htt, &tx_done);
		if (!status) {
			spin_lock_bh(&htt->tx_lock);
			ath10k_htt_tx_mgmt_dec_pending(htt);
			spin_unlock_bh(&htt->tx_lock);
		}
		ath10k_mac_tx_push_pending(ar);
		break;
	}
	case HTT_T2H_MSG_TYPE_TX_COMPL_IND:
		ath10k_htt_rx_tx_compl_ind(htt->ar, skb);
		tasklet_schedule(&htt->txrx_compl_task);
		break;
	case HTT_T2H_MSG_TYPE_SEC_IND: {
		struct ath10k *ar = htt->ar;
		struct htt_security_indication *ev = &resp->security_indication;

		ath10k_dbg(ar, ATH10K_DBG_HTT,
			   "sec ind peer_id %d unicast %d type %d\n",
			  __le16_to_cpu(ev->peer_id),
			  !!(ev->flags & HTT_SECURITY_IS_UNICAST),
			  MS(ev->flags, HTT_SECURITY_TYPE));
		complete(&ar->install_key_done);
		break;
	}
	case HTT_T2H_MSG_TYPE_RX_FRAG_IND: {
		ath10k_dbg_dump(ar, ATH10K_DBG_HTT_DUMP, NULL, "htt event: ",
				skb->data, skb->len);
		ath10k_htt_rx_frag_handler(htt);
		break;
	}
	case HTT_T2H_MSG_TYPE_TEST:
		break;
	case HTT_T2H_MSG_TYPE_STATS_CONF:
		trace_ath10k_htt_stats(ar, skb->data, skb->len);
		break;
	case HTT_T2H_MSG_TYPE_TX_INSPECT_IND:
		/* Firmware can return tx frames if it's unable to fully
		 * process them and suspects host may be able to fix it. ath10k
		 * sends all tx frames as already inspected so this shouldn't
		 * happen unless fw has a bug.
		 */
		ath10k_warn(ar, "received an unexpected htt tx inspect event\n");
		break;
	case HTT_T2H_MSG_TYPE_RX_ADDBA:
		ath10k_htt_rx_addba(ar, resp);
		break;
	case HTT_T2H_MSG_TYPE_RX_DELBA:
		ath10k_htt_rx_delba(ar, resp);
		break;
	case HTT_T2H_MSG_TYPE_PKTLOG: {
		struct ath10k_pktlog_hdr *hdr =
			(struct ath10k_pktlog_hdr *)resp->pktlog_msg.payload;

		trace_ath10k_htt_pktlog(ar, resp->pktlog_msg.payload,
					sizeof(*hdr) +
					__le16_to_cpu(hdr->size));
		break;
	}
	case HTT_T2H_MSG_TYPE_RX_FLUSH: {
		/* Ignore this event because mac80211 takes care of Rx
		 * aggregation reordering.
		 */
		break;
	}
	case HTT_T2H_MSG_TYPE_RX_IN_ORD_PADDR_IND: {
		skb_queue_tail(&htt->rx_in_ord_compl_q, skb);
		tasklet_schedule(&htt->txrx_compl_task);
		return false;
	}
	case HTT_T2H_MSG_TYPE_TX_CREDIT_UPDATE_IND:
		break;
	case HTT_T2H_MSG_TYPE_CHAN_CHANGE: {
		u32 phymode = __le32_to_cpu(resp->chan_change.phymode);
		u32 freq = __le32_to_cpu(resp->chan_change.freq);

		ar->tgt_oper_chan =
			__ieee80211_get_channel(ar->hw->wiphy, freq);
		ath10k_dbg(ar, ATH10K_DBG_HTT,
			   "htt chan change freq %u phymode %s\n",
			   freq, ath10k_wmi_phymode_str(phymode));
		break;
	}
	case HTT_T2H_MSG_TYPE_AGGR_CONF:
		break;
	case HTT_T2H_MSG_TYPE_TX_FETCH_IND: {
		struct sk_buff *tx_fetch_ind = skb_copy(skb, GFP_ATOMIC);

		if (!tx_fetch_ind) {
			ath10k_warn(ar, "failed to copy htt tx fetch ind\n");
			break;
		}
		skb_queue_tail(&htt->tx_fetch_ind_q, tx_fetch_ind);
		tasklet_schedule(&htt->txrx_compl_task);
		break;
	}
	case HTT_T2H_MSG_TYPE_TX_FETCH_CONFIRM:
		ath10k_htt_rx_tx_fetch_confirm(ar, skb);
		break;
	case HTT_T2H_MSG_TYPE_TX_MODE_SWITCH_IND:
		ath10k_htt_rx_tx_mode_switch_ind(ar, skb);
		break;
	case HTT_T2H_MSG_TYPE_EN_STATS:
	default:
		ath10k_warn(ar, "htt event (%d) not handled\n",
			    resp->hdr.msg_type);
		ath10k_dbg_dump(ar, ATH10K_DBG_HTT_DUMP, NULL, "htt event: ",
				skb->data, skb->len);
		break;
	};
	return true;
}
EXPORT_SYMBOL(ath10k_htt_t2h_msg_handler);

void ath10k_htt_rx_pktlog_completion_handler(struct ath10k *ar,
					     struct sk_buff *skb)
{
	trace_ath10k_htt_pktlog(ar, skb->data, skb->len);
	dev_kfree_skb_any(skb);
}
EXPORT_SYMBOL(ath10k_htt_rx_pktlog_completion_handler);

static void ath10k_htt_txrx_compl_task(unsigned long ptr)
{
	struct ath10k_htt *htt = (struct ath10k_htt *)ptr;
	struct ath10k *ar = htt->ar;
	struct htt_tx_done tx_done = {};
	struct sk_buff_head rx_q;
	struct sk_buff_head rx_ind_q;
	struct sk_buff_head tx_ind_q;
	struct sk_buff *skb;
	unsigned long flags;
	int num_mpdus;

	__skb_queue_head_init(&rx_q);
	__skb_queue_head_init(&rx_ind_q);
	__skb_queue_head_init(&tx_ind_q);

	spin_lock_irqsave(&htt->rx_in_ord_compl_q.lock, flags);
	skb_queue_splice_init(&htt->rx_in_ord_compl_q, &rx_ind_q);
	spin_unlock_irqrestore(&htt->rx_in_ord_compl_q.lock, flags);

	spin_lock_irqsave(&htt->tx_fetch_ind_q.lock, flags);
	skb_queue_splice_init(&htt->tx_fetch_ind_q, &tx_ind_q);
	spin_unlock_irqrestore(&htt->tx_fetch_ind_q.lock, flags);

	/* kfifo_get: called only within txrx_tasklet so it's neatly serialized.
	 * From kfifo_get() documentation:
	 *  Note that with only one concurrent reader and one concurrent writer,
	 *  you don't need extra locking to use these macro.
	 */
	while (kfifo_get(&htt->txdone_fifo, &tx_done))
		ath10k_txrx_tx_unref(htt, &tx_done);

	while ((skb = __skb_dequeue(&tx_ind_q))) {
		ath10k_htt_rx_tx_fetch_ind(ar, skb);
		dev_kfree_skb_any(skb);
	}

	ath10k_mac_tx_push_pending(ar);

	num_mpdus = atomic_read(&htt->num_mpdus_ready);
	atomic_sub(num_mpdus, &htt->num_mpdus_ready);

	while (num_mpdus--) {
		if (ath10k_htt_rx_handle_amsdu(htt))
			break;
	}

	while ((skb = __skb_dequeue(&rx_ind_q))) {
		spin_lock_bh(&htt->rx_ring.lock);
		ath10k_htt_rx_in_ord_ind(ar, skb);
		spin_unlock_bh(&htt->rx_ring.lock);
		dev_kfree_skb_any(skb);
	}

	tasklet_schedule(&htt->rx_replenish_task);
}