diff mbox

[14/29] ath10k: add htt_rx.c

Message ID 20130515144441.4492.37177.stgit@localhost6.localdomain6 (mailing list archive)
State Not Applicable, archived
Headers show

Commit Message

Kalle Valo May 15, 2013, 2:44 p.m. UTC
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
---
 drivers/net/wireless/ath/ath10k/htt_rx.c | 1167 ++++++++++++++++++++++++++++++
 1 file changed, 1167 insertions(+)
 create mode 100644 drivers/net/wireless/ath/ath10k/htt_rx.c


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diff mbox

Patch

diff --git a/drivers/net/wireless/ath/ath10k/htt_rx.c b/drivers/net/wireless/ath/ath10k/htt_rx.c
new file mode 100644
index 0000000..de058d7
--- /dev/null
+++ b/drivers/net/wireless/ath/ath10k/htt_rx.c
@@ -0,0 +1,1167 @@ 
+/*
+ * 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 "htc.h"
+#include "htt.h"
+#include "txrx.h"
+#include "debug.h"
+
+#include <linux/log2.h>
+
+/* slightly larger than one large A-MPDU */
+#define HTT_RX_RING_SIZE_MIN 128
+
+/* roughly 20 ms @ 1 Gbps of 1500B MSDUs */
+#define HTT_RX_RING_SIZE_MAX 2048
+
+#define HTT_RX_AVG_FRM_BYTES 1000
+
+/* ms, very conservative */
+#define HTT_RX_HOST_LATENCY_MAX_MS 20
+
+/* ms, conservative */
+#define HTT_RX_HOST_LATENCY_WORST_LIKELY_MS 10
+
+/* 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_ring_size(struct ath10k_htt *htt)
+{
+	int size;
+
+	/*
+	 * It is expected that the host CPU will typically be able to
+	 * service the rx indication from one A-MPDU before the rx
+	 * indication from the subsequent A-MPDU happens, roughly 1-2 ms
+	 * later. However, the rx ring should be sized very conservatively,
+	 * to accomodate the worst reasonable delay before the host CPU
+	 * services a rx indication interrupt.
+	 *
+	 * The rx ring need not be kept full of empty buffers. In theory,
+	 * the htt host SW can dynamically track the low-water mark in the
+	 * rx ring, and dynamically adjust the level to which the rx ring
+	 * is filled with empty buffers, to dynamically meet the desired
+	 * low-water mark.
+	 *
+	 * In contrast, it's difficult to resize the rx ring itself, once
+	 * it's in use. Thus, the ring itself should be sized very
+	 * conservatively, while the degree to which the ring is filled
+	 * with empty buffers should be sized moderately conservatively.
+	 */
+
+	/* 1e6 bps/mbps / 1e3 ms per sec = 1000 */
+	size =
+	    htt->max_throughput_mbps +
+	    1000  /
+	    (8 * HTT_RX_AVG_FRM_BYTES) * HTT_RX_HOST_LATENCY_MAX_MS;
+
+	if (size < HTT_RX_RING_SIZE_MIN)
+		size = HTT_RX_RING_SIZE_MIN;
+
+	if (size > HTT_RX_RING_SIZE_MAX)
+		size = HTT_RX_RING_SIZE_MAX;
+
+	size = roundup_pow_of_two(size);
+
+	return size;
+}
+
+static int ath10k_htt_rx_ring_fill_level(struct ath10k_htt *htt)
+{
+	int size;
+
+	/* 1e6 bps/mbps / 1e3 ms per sec = 1000 */
+	size =
+	    htt->max_throughput_mbps *
+	    1000  /
+	    (8 * HTT_RX_AVG_FRM_BYTES) * HTT_RX_HOST_LATENCY_WORST_LIKELY_MS;
+
+	/*
+	 * Make sure the fill level is at least 1 less than the ring size.
+	 * Leaving 1 element empty allows the SW to easily distinguish
+	 * between a full ring vs. an empty ring.
+	 */
+	if (size >= htt->rx_ring.size)
+		size = htt->rx_ring.size - 1;
+
+	return size;
+}
+
+static void ath10k_htt_rx_ring_free(struct ath10k_htt *htt)
+{
+	struct sk_buff *skb;
+	struct ath10k_skb_cb *cb;
+	int i;
+
+	for (i = 0; i < htt->rx_ring.fill_cnt; i++) {
+		skb = htt->rx_ring.netbufs_ring[i];
+		cb = ATH10K_SKB_CB(skb);
+		dma_unmap_single(htt->ar->dev, cb->paddr,
+				 skb->len + skb_tailroom(skb),
+				 DMA_FROM_DEVICE);
+		dev_kfree_skb_any(skb);
+	}
+
+	htt->rx_ring.fill_cnt = 0;
+}
+
+static int __ath10k_htt_rx_ring_fill_n(struct ath10k_htt *htt, int num)
+{
+	struct htt_rx_desc *rx_desc;
+	struct sk_buff *skb;
+	dma_addr_t paddr;
+	int ret = 0, idx;
+
+	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;
+		}
+
+		ATH10K_SKB_CB(skb)->paddr = paddr;
+		htt->rx_ring.netbufs_ring[idx] = skb;
+		htt->rx_ring.paddrs_ring[idx] = __cpu_to_le32(paddr);
+		htt->rx_ring.fill_cnt++;
+
+		num--;
+		idx++;
+		idx &= htt->rx_ring.size_mask;
+	}
+
+fail:
+	*(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_to_fill;
+
+	spin_lock_bh(&htt->rx_ring.lock);
+	num_to_fill = htt->rx_ring.fill_level - htt->rx_ring.fill_cnt;
+	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));
+	}
+	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);
+}
+
+static unsigned ath10k_htt_rx_ring_elems(struct ath10k_htt *htt)
+{
+	return (__le32_to_cpu(*htt->rx_ring.alloc_idx.vaddr) -
+		htt->rx_ring.sw_rd_idx.msdu_payld) & htt->rx_ring.size_mask;
+}
+
+void ath10k_htt_rx_detach(struct ath10k_htt *htt)
+{
+	int sw_rd_idx = htt->rx_ring.sw_rd_idx.msdu_payld;
+
+	del_timer_sync(&htt->rx_ring.refill_retry_timer);
+
+	while (sw_rd_idx != __le32_to_cpu(*(htt->rx_ring.alloc_idx.vaddr))) {
+		struct sk_buff *skb =
+				htt->rx_ring.netbufs_ring[sw_rd_idx];
+		struct ath10k_skb_cb *cb = ATH10K_SKB_CB(skb);
+
+		dma_unmap_single(htt->ar->dev, cb->paddr,
+				 skb->len + skb_tailroom(skb),
+				 DMA_FROM_DEVICE);
+		dev_kfree_skb_any(htt->rx_ring.netbufs_ring[sw_rd_idx]);
+		sw_rd_idx++;
+		sw_rd_idx &= htt->rx_ring.size_mask;
+	}
+
+	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)
+{
+	int idx;
+	struct sk_buff *msdu;
+
+	spin_lock_bh(&htt->rx_ring.lock);
+
+	if (ath10k_htt_rx_ring_elems(htt) == 0)
+		ath10k_warn("htt rx ring is empty!\n");
+
+	idx = htt->rx_ring.sw_rd_idx.msdu_payld;
+	msdu = htt->rx_ring.netbufs_ring[idx];
+
+	idx++;
+	idx &= htt->rx_ring.size_mask;
+	htt->rx_ring.sw_rd_idx.msdu_payld = idx;
+	htt->rx_ring.fill_cnt--;
+
+	spin_unlock_bh(&htt->rx_ring.lock);
+	return msdu;
+}
+
+static void ath10k_htt_rx_free_msdu_chain(struct sk_buff *skb)
+{
+	struct sk_buff *next;
+
+	while (skb) {
+		next = skb->next;
+		dev_kfree_skb_any(skb);
+		skb = next;
+	}
+}
+
+static int ath10k_htt_rx_amsdu_pop(struct ath10k_htt *htt,
+				   u8 **fw_desc, int *fw_desc_len,
+				   struct sk_buff **head_msdu,
+				   struct sk_buff **tail_msdu)
+{
+	int msdu_len, msdu_chaining = 0;
+	struct sk_buff *msdu;
+	struct htt_rx_desc *rx_desc;
+
+	if (ath10k_htt_rx_ring_elems(htt) == 0)
+		ath10k_warn("htt rx ring is empty!\n");
+
+	if (htt->rx_confused) {
+		ath10k_warn("htt is confused. refusing rx\n");
+		return 0;
+	}
+
+	msdu = *head_msdu = ath10k_htt_rx_netbuf_pop(htt);
+	while (msdu) {
+		int last_msdu, msdu_len_invalid, msdu_chained;
+
+		dma_unmap_single(htt->ar->dev,
+				 ATH10K_SKB_CB(msdu)->paddr,
+				 msdu->len + skb_tailroom(msdu),
+				 DMA_FROM_DEVICE);
+
+		ath10k_dbg_dump(ATH10K_DBG_HTT_DUMP, NULL, "htt rx: ",
+				msdu->data, msdu->len + skb_tailroom(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)) {
+			ath10k_htt_rx_free_msdu_chain(*head_msdu);
+			*head_msdu = NULL;
+			msdu = NULL;
+			ath10k_err("htt rx stopped. cannot recover\n");
+			htt->rx_confused = true;
+			break;
+		}
+
+		/*
+		 * Copy the FW rx descriptor for this MSDU from the rx
+		 * indication message into the MSDU's netbuf. HL uses the
+		 * same rx indication message definition as LL, and simply
+		 * appends new info (fields from the HW rx desc, and the
+		 * MSDU payload itself). So, the offset into the rx
+		 * indication message only has to account for the standard
+		 * offset of the per-MSDU FW rx desc info within the
+		 * message, and how many bytes of the per-MSDU FW rx desc
+		 * info have already been consumed. (And the endianness of
+		 * the host, since for a big-endian host, the rx ind
+		 * message contents, including the per-MSDU rx desc bytes,
+		 * were byteswapped during upload.)
+		 */
+		if (*fw_desc_len > 0) {
+			rx_desc->fw_desc.info0 = **fw_desc;
+			/*
+			 * The target is expected to only provide the basic
+			 * per-MSDU rx descriptors. Just to be sure, verify
+			 * that the target has not attached extension data
+			 * (e.g. LRO flow ID).
+			 */
+
+			/* or more, if there's extension data */
+			(*fw_desc)++;
+			(*fw_desc_len)--;
+		} else {
+			/*
+			 * When an oversized AMSDU happened, FW will lost
+			 * some of MSDU status - in this case, the FW
+			 * descriptors provided will be less than the
+			 * actual MSDUs inside this MPDU. Mark the FW
+			 * descriptors so that it will still deliver to
+			 * upper stack, if no CRC error for this MPDU.
+			 *
+			 * FIX THIS - the FW descriptors are actually for
+			 * MSDUs in the end of this A-MSDU instead of the
+			 * beginning.
+			 */
+			rx_desc->fw_desc.info0 = 0;
+		}
+
+		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.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;
+
+		/* FIXME: Do chained buffers include htt_rx_desc or not? */
+		while (msdu_chained--) {
+			struct sk_buff *next = ath10k_htt_rx_netbuf_pop(htt);
+
+			dma_unmap_single(htt->ar->dev,
+					 ATH10K_SKB_CB(next)->paddr,
+					 next->len + skb_tailroom(next),
+					 DMA_FROM_DEVICE);
+
+			ath10k_dbg_dump(ATH10K_DBG_HTT_DUMP, NULL, "htt rx: ",
+					next->data,
+					next->len + skb_tailroom(next));
+
+			skb_trim(next, 0);
+			skb_put(next, min(msdu_len, HTT_RX_BUF_SIZE));
+			msdu_len -= next->len;
+
+			msdu->next = next;
+			msdu = next;
+			msdu_chaining = 1;
+		}
+
+		if (msdu_len > 0) {
+			/* This may suggest FW bug? */
+			ath10k_warn("htt rx msdu len not consumed (%d)\n",
+				    msdu_len);
+		}
+
+		last_msdu = __le32_to_cpu(rx_desc->msdu_end.info0) &
+				RX_MSDU_END_INFO0_LAST_MSDU;
+
+		if (last_msdu) {
+			msdu->next = NULL;
+			break;
+		} else {
+			struct sk_buff *next = ath10k_htt_rx_netbuf_pop(htt);
+			msdu->next = next;
+			msdu = next;
+		}
+	}
+	*tail_msdu = msdu;
+
+	/*
+	 * 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;
+}
+
+int ath10k_htt_rx_attach(struct ath10k_htt *htt)
+{
+	dma_addr_t paddr;
+	void *vaddr;
+	struct timer_list *timer = &htt->rx_ring.refill_retry_timer;
+
+	htt->rx_ring.size = ath10k_htt_rx_ring_size(htt);
+	if (!is_power_of_2(htt->rx_ring.size)) {
+		ath10k_warn("htt rx ring size is not power of 2\n");
+		return -EINVAL;
+	}
+
+	htt->rx_ring.size_mask = htt->rx_ring.size - 1;
+
+	/*
+	 * Set the initial value for the level to which the rx ring
+	 * should be filled, based on the max throughput and the
+	 * worst likely latency for the host to fill the rx ring
+	 * with new buffers. In theory, this fill level can be
+	 * dynamically adjusted from the initial value set here, to
+	 * reflect the actual host latency rather than a
+	 * conservative assumption about the host latency.
+	 */
+	htt->rx_ring.fill_level = ath10k_htt_rx_ring_fill_level(htt);
+
+	htt->rx_ring.netbufs_ring =
+		kmalloc(htt->rx_ring.size * sizeof(struct sk_buff *),
+			GFP_KERNEL);
+	if (!htt->rx_ring.netbufs_ring)
+		goto err_netbuf;
+
+	vaddr = dma_alloc_coherent(htt->ar->dev,
+		   (htt->rx_ring.size * sizeof(htt->rx_ring.paddrs_ring)),
+		   &paddr, GFP_DMA);
+	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_DMA);
+	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 = 0;
+	*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;
+	if (__ath10k_htt_rx_ring_fill_n(htt, htt->rx_ring.fill_level))
+		goto err_fill_ring;
+
+	ath10k_dbg(ATH10K_DBG_HTT, "HTT RX ring size: %d, fill_level: %d\n",
+		   htt->rx_ring.size, htt->rx_ring.fill_level);
+	return 0;
+
+err_fill_ring:
+	ath10k_htt_rx_ring_free(htt);
+	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);
+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(enum htt_rx_mpdu_encrypt_type type)
+{
+	switch (type) {
+	case HTT_RX_MPDU_ENCRYPT_WEP40:
+	case HTT_RX_MPDU_ENCRYPT_WEP104:
+		return 4;
+	case HTT_RX_MPDU_ENCRYPT_TKIP_WITHOUT_MIC:
+	case HTT_RX_MPDU_ENCRYPT_WEP128: /* not tested */
+	case HTT_RX_MPDU_ENCRYPT_TKIP_WPA:
+	case HTT_RX_MPDU_ENCRYPT_WAPI: /* not tested */
+	case HTT_RX_MPDU_ENCRYPT_AES_CCM_WPA2:
+		return 8;
+	case HTT_RX_MPDU_ENCRYPT_NONE:
+		return 0;
+	}
+
+	ath10k_warn("unknown encryption type %d\n", type);
+	return 0;
+}
+
+static int ath10k_htt_rx_crypto_tail_len(enum htt_rx_mpdu_encrypt_type type)
+{
+	switch (type) {
+	case HTT_RX_MPDU_ENCRYPT_NONE:
+	case HTT_RX_MPDU_ENCRYPT_WEP40:
+	case HTT_RX_MPDU_ENCRYPT_WEP104:
+	case HTT_RX_MPDU_ENCRYPT_WEP128:
+	case HTT_RX_MPDU_ENCRYPT_WAPI:
+		return 0;
+	case HTT_RX_MPDU_ENCRYPT_TKIP_WITHOUT_MIC:
+	case HTT_RX_MPDU_ENCRYPT_TKIP_WPA:
+		return 4;
+	case HTT_RX_MPDU_ENCRYPT_AES_CCM_WPA2:
+		return 8;
+	}
+
+	ath10k_warn("unknown encryption type %d\n", type);
+	return 0;
+}
+
+/* Applies for first msdu in chain, before altering it. */
+static struct ieee80211_hdr *ath10k_htt_rx_skb_get_hdr(struct sk_buff *skb)
+{
+	struct htt_rx_desc *rxd;
+	enum rx_msdu_decap_format fmt;
+
+	rxd = (void *)skb->data - sizeof(*rxd);
+	fmt = MS(__le32_to_cpu(rxd->msdu_start.info1),
+			RX_MSDU_START_INFO1_DECAP_FORMAT);
+
+	if (fmt == RX_MSDU_DECAP_RAW)
+		return (void *)skb->data;
+	else
+		return (void *)skb->data - RX_HTT_HDR_STATUS_LEN;
+}
+
+/* This function only applies for first msdu in an msdu chain */
+static bool ath10k_htt_rx_hdr_is_amsdu(struct ieee80211_hdr *hdr)
+{
+	if (ieee80211_is_data_qos(hdr->frame_control)) {
+		u8 *qc = ieee80211_get_qos_ctl(hdr);
+		if (qc[0] & 0x80)
+			return true;
+	}
+	return false;
+}
+
+static int ath10k_htt_rx_amsdu(struct ath10k_htt *htt,
+			struct htt_rx_info *info)
+{
+	struct htt_rx_desc *rxd;
+	struct sk_buff *amsdu;
+	struct sk_buff *first;
+	struct ieee80211_hdr *hdr;
+	struct sk_buff *skb = info->skb;
+	enum rx_msdu_decap_format fmt;
+	enum htt_rx_mpdu_encrypt_type enctype;
+	unsigned int hdr_len;
+	int crypto_len;
+
+	rxd = (void *)skb->data - sizeof(*rxd);
+	fmt = MS(__le32_to_cpu(rxd->msdu_start.info1),
+			RX_MSDU_START_INFO1_DECAP_FORMAT);
+	enctype = MS(__le32_to_cpu(rxd->mpdu_start.info0),
+			RX_MPDU_START_INFO0_ENCRYPT_TYPE);
+
+	/* FIXME: No idea what assumptions are safe here. Need logs */
+	if ((fmt == RX_MSDU_DECAP_RAW && skb->next) ||
+	    (fmt == RX_MSDU_DECAP_8023_SNAP_LLC)) {
+		ath10k_htt_rx_free_msdu_chain(skb->next);
+		skb->next = NULL;
+		return -ENOTSUPP;
+	}
+
+	/* A-MSDU max is a little less than 8K */
+	amsdu = dev_alloc_skb(8*1024);
+	if (!amsdu) {
+		ath10k_warn("A-MSDU allocation failed\n");
+		ath10k_htt_rx_free_msdu_chain(skb->next);
+		skb->next = NULL;
+		return -ENOMEM;
+	}
+
+	if (fmt >= RX_MSDU_DECAP_NATIVE_WIFI) {
+		int hdrlen;
+
+		hdr = (void *)rxd->rx_hdr_status;
+		hdrlen = ieee80211_hdrlen(hdr->frame_control);
+		memcpy(skb_put(amsdu, hdrlen), hdr, hdrlen);
+	}
+
+	first = skb;
+	while (skb) {
+		void *decap_hdr;
+		int decap_len = 0;
+
+		rxd = (void *)skb->data - sizeof(*rxd);
+		fmt = MS(__le32_to_cpu(rxd->msdu_start.info1),
+				RX_MSDU_START_INFO1_DECAP_FORMAT);
+		decap_hdr = (void *)rxd->rx_hdr_status;
+
+		if (skb == first) {
+			/* We receive linked A-MSDU subframe skbuffs. The
+			 * first one contains the original 802.11 header (and
+			 * possible crypto param) in the RX descriptor. The
+			 * A-MSDU subframe header follows that. Each part is
+			 * aligned to 4 byte boundary. */
+
+			hdr = (void *)amsdu->data;
+			hdr_len = ieee80211_hdrlen(hdr->frame_control);
+			crypto_len = ath10k_htt_rx_crypto_param_len(enctype);
+
+			decap_hdr += roundup(hdr_len, 4);
+			decap_hdr += roundup(crypto_len, 4);
+		}
+
+		if (fmt == RX_MSDU_DECAP_ETHERNET2_DIX) {
+			/* Ethernet2 decap inserts ethernet header in place of
+			 * A-MSDU subframe header. */
+			skb_pull(skb, 6 + 6 + 2);
+
+			/* A-MSDU subframe header length */
+			decap_len += 6 + 6 + 2;
+
+			/* Ethernet2 decap also strips the LLC/SNAP so we need
+			 * to re-insert it. The LLC/SNAP follows A-MSDU
+			 * subframe header. */
+			/* FIXME: Not all LLCs are 8 bytes long */
+			decap_len += 8;
+
+			memcpy(skb_put(amsdu, decap_len), decap_hdr, decap_len);
+		}
+
+		if (fmt == RX_MSDU_DECAP_NATIVE_WIFI) {
+			/* Native Wifi decap inserts regular 802.11 header
+			 * in place of A-MSDU subframe header. */
+			hdr = (struct ieee80211_hdr *)skb->data;
+			skb_pull(skb, ieee80211_hdrlen(hdr->frame_control));
+
+			/* A-MSDU subframe header length */
+			decap_len += 6 + 6 + 2;
+
+			memcpy(skb_put(amsdu, decap_len), decap_hdr, decap_len);
+		}
+
+		if (fmt == RX_MSDU_DECAP_RAW)
+			skb_trim(skb, skb->len - 4); /* remove FCS */
+
+		memcpy(skb_put(amsdu, skb->len), skb->data, skb->len);
+
+		/* A-MSDU subframes are padded to 4bytes
+		 * but relative to first subframe, not the whole MPDU */
+		if (skb->next && ((decap_len + skb->len) & 3)) {
+			int padlen = 4 - ((decap_len + skb->len) & 3);
+			memset(skb_put(amsdu, padlen), 0, padlen);
+		}
+
+		skb = skb->next;
+	}
+
+	info->skb = amsdu;
+	info->encrypt_type = enctype;
+
+	ath10k_htt_rx_free_msdu_chain(first);
+
+	return 0;
+}
+
+static int ath10k_htt_rx_msdu(struct ath10k_htt *htt, struct htt_rx_info *info)
+{
+	struct sk_buff *skb = info->skb;
+	struct htt_rx_desc *rxd;
+	struct ieee80211_hdr *hdr;
+	enum rx_msdu_decap_format fmt;
+	enum htt_rx_mpdu_encrypt_type enctype;
+
+	/* This shouldn't happen. If it does than it may be a FW bug. */
+	if (skb->next) {
+		ath10k_warn("received chained non A-MSDU frame\n");
+		ath10k_htt_rx_free_msdu_chain(skb->next);
+		skb->next = NULL;
+	}
+
+	rxd = (void *)skb->data - sizeof(*rxd);
+	fmt = MS(__le32_to_cpu(rxd->msdu_start.info1),
+			RX_MSDU_START_INFO1_DECAP_FORMAT);
+	enctype = MS(__le32_to_cpu(rxd->mpdu_start.info0),
+			RX_MPDU_START_INFO0_ENCRYPT_TYPE);
+	hdr = (void *)skb->data - RX_HTT_HDR_STATUS_LEN;
+
+	switch (fmt) {
+	case RX_MSDU_DECAP_RAW:
+		/* remove trailing FCS */
+		skb_trim(skb, skb->len - 4);
+		break;
+	case RX_MSDU_DECAP_NATIVE_WIFI:
+		/* nothing to do here */
+		break;
+	case RX_MSDU_DECAP_ETHERNET2_DIX:
+		/* macaddr[6] + macaddr[6] + ethertype[2] */
+		skb_pull(skb, 6 + 6 + 2);
+		break;
+	case RX_MSDU_DECAP_8023_SNAP_LLC:
+		/* macaddr[6] + macaddr[6] + len[2] */
+		/* we don't need this for non-A-MSDU */
+		skb_pull(skb, 6 + 6 + 2);
+		break;
+	}
+
+	if (fmt == RX_MSDU_DECAP_ETHERNET2_DIX) {
+		void *llc;
+		int llclen;
+
+		llclen = 8;
+		llc  = hdr;
+		llc += roundup(ieee80211_hdrlen(hdr->frame_control), 4);
+		llc += roundup(ath10k_htt_rx_crypto_param_len(enctype), 4);
+
+		skb_push(skb, llclen);
+		memcpy(skb->data, llc, llclen);
+	}
+
+	if (fmt >= RX_MSDU_DECAP_ETHERNET2_DIX) {
+		int len = ieee80211_hdrlen(hdr->frame_control);
+		skb_push(skb, len);
+		memcpy(skb->data, hdr, len);
+	}
+
+	info->skb = skb;
+	info->encrypt_type = enctype;
+	return 0;
+}
+
+static bool ath10k_htt_rx_has_decrypt_err(struct sk_buff *skb)
+{
+	struct htt_rx_desc *rxd;
+	u32 flags;
+
+	rxd = (void *)skb->data - sizeof(*rxd);
+	flags = __le32_to_cpu(rxd->attention.flags);
+
+	if (flags & RX_ATTENTION_FLAGS_DECRYPT_ERR)
+		return true;
+
+	return false;
+}
+
+static bool ath10k_htt_rx_has_fcs_err(struct sk_buff *skb)
+{
+	struct htt_rx_desc *rxd;
+	u32 flags;
+
+	rxd = (void *)skb->data - sizeof(*rxd);
+	flags = __le32_to_cpu(rxd->attention.flags);
+
+	if (flags & RX_ATTENTION_FLAGS_FCS_ERR)
+		return true;
+
+	return false;
+}
+
+static void ath10k_htt_rx_handler(struct ath10k_htt *htt,
+				  struct htt_rx_indication *rx)
+{
+	struct htt_rx_info info;
+	struct htt_rx_indication_mpdu_range *mpdu_ranges;
+	struct ieee80211_hdr *hdr;
+	int num_mpdu_ranges;
+	int fw_desc_len;
+	u8 *fw_desc;
+	int i, j;
+	int ret;
+
+	memset(&info, 0, sizeof(info));
+
+	fw_desc_len = __le16_to_cpu(rx->prefix.fw_rx_desc_bytes);
+	fw_desc = (u8 *)&rx->fw_desc;
+
+	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(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++) {
+		info.status = mpdu_ranges[i].mpdu_range_status;
+
+		for (j = 0; j < mpdu_ranges[i].mpdu_count; j++) {
+			struct sk_buff *msdu_head, *msdu_tail;
+			enum htt_rx_mpdu_status status;
+			int msdu_chaining;
+
+			msdu_head = NULL;
+			msdu_tail = NULL;
+			msdu_chaining = ath10k_htt_rx_amsdu_pop(htt,
+							 &fw_desc,
+							 &fw_desc_len,
+							 &msdu_head,
+							 &msdu_tail);
+
+			if (!msdu_head) {
+				ath10k_warn("htt rx no data!\n");
+				continue;
+			}
+
+			if (msdu_head->len == 0) {
+				ath10k_dbg(ATH10K_DBG_HTT,
+					   "htt rx dropping due to zero-len\n");
+				ath10k_htt_rx_free_msdu_chain(msdu_head);
+				continue;
+			}
+
+			if (ath10k_htt_rx_has_decrypt_err(msdu_head)) {
+				ath10k_htt_rx_free_msdu_chain(msdu_head);
+				continue;
+			}
+
+			status = info.status;
+
+			/* Skip mgmt frames while we handle this in WMI */
+			if (status == HTT_RX_IND_MPDU_STATUS_MGMT_CTRL) {
+				ath10k_htt_rx_free_msdu_chain(msdu_head);
+				continue;
+			}
+
+			if (status != HTT_RX_IND_MPDU_STATUS_OK &&
+			    status != HTT_RX_IND_MPDU_STATUS_TKIP_MIC_ERR &&
+			    !htt->ar->monitor_enabled) {
+				ath10k_dbg(ATH10K_DBG_HTT,
+					   "htt rx ignoring frame w/ status %d\n",
+					   status);
+				ath10k_htt_rx_free_msdu_chain(msdu_head);
+				continue;
+			}
+
+			/* FIXME: we do not support chaining yet.
+			 * this needs investigation */
+			if (msdu_chaining) {
+				ath10k_warn("msdu_chaining is true\n");
+				ath10k_htt_rx_free_msdu_chain(msdu_head);
+				continue;
+			}
+
+			info.skb     = msdu_head;
+			info.fcs_err = ath10k_htt_rx_has_fcs_err(msdu_head);
+			info.signal  = ATH10K_DEFAULT_NOISE_FLOOR;
+			info.signal += rx->ppdu.combined_rssi;
+
+			info.rate.info0 = rx->ppdu.info0;
+			info.rate.info1 = __le32_to_cpu(rx->ppdu.info1);
+			info.rate.info2 = __le32_to_cpu(rx->ppdu.info2);
+
+			hdr = ath10k_htt_rx_skb_get_hdr(msdu_head);
+
+			if (ath10k_htt_rx_hdr_is_amsdu(hdr))
+				ret = ath10k_htt_rx_amsdu(htt, &info);
+			else
+				ret = ath10k_htt_rx_msdu(htt, &info);
+
+			if (ret && !info.fcs_err) {
+				ath10k_warn("error processing msdus %d\n", ret);
+				dev_kfree_skb_any(info.skb);
+				continue;
+			}
+
+			if (ath10k_htt_rx_hdr_is_amsdu((void *)info.skb->data))
+				ath10k_dbg(ATH10K_DBG_HTT, "htt mpdu is amsdu\n");
+
+			ath10k_dbg_dump(ATH10K_DBG_HTT_DUMP, NULL, "htt mpdu: ",
+					info.skb->data, info.skb->len);
+			ath10k_process_rx(htt->ar, &info);
+		}
+	}
+
+	ath10k_htt_rx_msdu_buff_replenish(htt);
+}
+
+static void ath10k_htt_rx_frag_handler(struct ath10k_htt *htt,
+				struct htt_rx_fragment_indication *frag)
+{
+	struct sk_buff *msdu_head, *msdu_tail;
+	struct htt_rx_desc *rxd;
+	enum rx_msdu_decap_format fmt;
+	struct htt_rx_info info = {};
+	struct ieee80211_hdr *hdr;
+	int msdu_chaining;
+	bool tkip_mic_err;
+	bool decrypt_err;
+	u8 *fw_desc;
+	int fw_desc_len, hdrlen, paramlen;
+	int trim;
+
+	fw_desc_len = __le16_to_cpu(frag->fw_rx_desc_bytes);
+	fw_desc = (u8 *)frag->fw_msdu_rx_desc;
+
+	msdu_head = NULL;
+	msdu_tail = NULL;
+	msdu_chaining = ath10k_htt_rx_amsdu_pop(htt, &fw_desc, &fw_desc_len,
+						&msdu_head, &msdu_tail);
+
+	ath10k_dbg(ATH10K_DBG_HTT_DUMP, "htt rx frag ahead\n");
+
+	if (!msdu_head) {
+		ath10k_warn("htt rx frag no data\n");
+		return;
+	}
+
+	if (msdu_chaining || msdu_head != msdu_tail) {
+		ath10k_warn("aggregation with fragmentation?!\n");
+		ath10k_htt_rx_free_msdu_chain(msdu_head);
+		return;
+	}
+
+	/* FIXME: implement signal strength */
+
+	hdr = (struct ieee80211_hdr *)msdu_head->data;
+	rxd = (void *)msdu_head->data - sizeof(*rxd);
+	tkip_mic_err = !!(__le32_to_cpu(rxd->attention.flags) &
+				RX_ATTENTION_FLAGS_TKIP_MIC_ERR);
+	decrypt_err = !!(__le32_to_cpu(rxd->attention.flags) &
+				RX_ATTENTION_FLAGS_DECRYPT_ERR);
+	fmt = MS(__le32_to_cpu(rxd->msdu_start.info1),
+			RX_MSDU_START_INFO1_DECAP_FORMAT);
+
+	if (fmt != RX_MSDU_DECAP_RAW) {
+		ath10k_warn("we dont support non-raw fragmented rx yet\n");
+		dev_kfree_skb_any(msdu_head);
+		goto end;
+	}
+
+	info.skb = msdu_head;
+	info.status = HTT_RX_IND_MPDU_STATUS_OK;
+	info.encrypt_type = MS(__le32_to_cpu(rxd->mpdu_start.info0),
+				RX_MPDU_START_INFO0_ENCRYPT_TYPE);
+
+	if (tkip_mic_err) {
+		ath10k_warn("tkip mic error\n");
+		info.status = HTT_RX_IND_MPDU_STATUS_TKIP_MIC_ERR;
+	}
+
+	if (decrypt_err) {
+		ath10k_warn("decryption err in fragmented rx\n");
+		dev_kfree_skb_any(info.skb);
+		goto end;
+	}
+
+	if (info.encrypt_type != HTT_RX_MPDU_ENCRYPT_NONE) {
+		hdrlen = ieee80211_hdrlen(hdr->frame_control);
+		paramlen = ath10k_htt_rx_crypto_param_len(info.encrypt_type);
+
+		/* It is more efficient to move the header than the payload */
+		memmove((void *)info.skb->data + paramlen,
+			(void *)info.skb->data,
+			hdrlen);
+		skb_pull(info.skb, paramlen);
+		hdr = (struct ieee80211_hdr *)info.skb->data;
+	}
+
+	/* remove trailing FCS */
+	trim  = 4;
+
+	/* remove crypto trailer */
+	trim += ath10k_htt_rx_crypto_tail_len(info.encrypt_type);
+
+	/* last fragment of TKIP frags has MIC */
+	if (!ieee80211_has_morefrags(hdr->frame_control) &&
+	    info.encrypt_type == HTT_RX_MPDU_ENCRYPT_TKIP_WPA)
+		trim += 8;
+
+	if (trim > info.skb->len) {
+		ath10k_warn("htt rx fragment: trailer longer than the frame itself? drop\n");
+		dev_kfree_skb_any(info.skb);
+		goto end;
+	}
+
+	skb_trim(info.skb, info.skb->len - trim);
+
+	ath10k_dbg_dump(ATH10K_DBG_HTT_DUMP, NULL, "htt frag mpdu: ",
+			info.skb->data, info.skb->len);
+	ath10k_process_rx(htt->ar, &info);
+
+end:
+	if (fw_desc_len > 0) {
+		ath10k_dbg(ATH10K_DBG_HTT,
+			   "expecting more fragmented rx in one indication %d\n",
+			   fw_desc_len);
+	}
+}
+
+void 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;
+
+	/* confirm alignment */
+	if (!IS_ALIGNED((unsigned long)skb->data, 4))
+		ath10k_warn("unaligned htt message, expect trouble\n");
+
+	ath10k_dbg(ATH10K_DBG_HTT, "HTT RX, msg_type: 0x%0X\n",
+		   resp->hdr.msg_type);
+	switch (resp->hdr.msg_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_handler(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:
+			break;
+		case HTT_MGMT_TX_STATUS_RETRY:
+			tx_done.no_ack = true;
+			break;
+		case HTT_MGMT_TX_STATUS_DROP:
+			tx_done.discard = true;
+			break;
+		}
+
+		ath10k_txrx_tx_completed(htt, &tx_done);
+		break;
+	}
+	case HTT_T2H_MSG_TYPE_TX_COMPL_IND: {
+		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.no_ack = true;
+			break;
+		case HTT_DATA_TX_STATUS_OK:
+			break;
+		case HTT_DATA_TX_STATUS_DISCARD:
+		case HTT_DATA_TX_STATUS_POSTPONE:
+		case HTT_DATA_TX_STATUS_DOWNLOAD_FAIL:
+			tx_done.discard = true;
+			break;
+		default:
+			ath10k_warn("unhandled tx completion status %d\n",
+				    status);
+			tx_done.discard = true;
+			break;
+		}
+
+		ath10k_dbg(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);
+			ath10k_txrx_tx_completed(htt, &tx_done);
+		}
+		break;
+	}
+	case HTT_T2H_MSG_TYPE_SEC_IND: {
+		struct ath10k *ar = htt->ar;
+		struct htt_security_indication *ev = &resp->security_indication;
+
+		ath10k_dbg(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(ATH10K_DBG_HTT_DUMP, NULL, "htt event: ",
+				skb->data, skb->len);
+		ath10k_htt_rx_frag_handler(htt, &resp->rx_frag_ind);
+		break;
+	}
+	case HTT_T2H_MSG_TYPE_TEST:
+		/* FIX THIS */
+		break;
+	case HTT_T2H_MSG_TYPE_TX_INSPECT_IND:
+	case HTT_T2H_MSG_TYPE_STATS_CONF:
+	case HTT_T2H_MSG_TYPE_RX_ADDBA:
+	case HTT_T2H_MSG_TYPE_RX_DELBA:
+	case HTT_T2H_MSG_TYPE_RX_FLUSH:
+	default:
+		ath10k_dbg(ATH10K_DBG_HTT, "htt event (%d) not handled\n",
+			   resp->hdr.msg_type);
+		ath10k_dbg_dump(ATH10K_DBG_HTT_DUMP, NULL, "htt event: ",
+				skb->data, skb->len);
+		break;
+	};
+
+	/* Free the indication buffer */
+	dev_kfree_skb_any(skb);
+}