drivers/net/wireless/ath/wil6210/rx_reorder.c - nest-learning-thermostat/6.0/linux-imx-4.9.88 - Git at Google

 /*
  * Copyright (c) 2014-2016 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 "wil6210.h"
 #include "txrx.h"

 #define SEQ_MODULO 0x1000
 #define SEQ_MASK   0xfff

 static inline int seq_less(u16 sq1, u16 sq2)
 {
 	return ((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1);
 }

 static inline u16 seq_inc(u16 sq)
 {
 	return (sq + 1) & SEQ_MASK;
 }

 static inline u16 seq_sub(u16 sq1, u16 sq2)
 {
 	return (sq1 - sq2) & SEQ_MASK;
 }

 static inline int reorder_index(struct wil_tid_ampdu_rx *r, u16 seq)
 {
 	return seq_sub(seq, r->ssn) % r->buf_size;
 }

 static void wil_release_reorder_frame(struct wil6210_priv *wil,
 				      struct wil_tid_ampdu_rx *r,
 				      int index)
 {
 	struct net_device *ndev = wil_to_ndev(wil);
 	struct sk_buff *skb = r->reorder_buf[index];

 	if (!skb)
 		goto no_frame;

 	/* release the frame from the reorder ring buffer */
 	r->stored_mpdu_num--;
 	r->reorder_buf[index] = NULL;
 	wil_netif_rx_any(skb, ndev);

 no_frame:
 	r->head_seq_num = seq_inc(r->head_seq_num);
 }

 static void wil_release_reorder_frames(struct wil6210_priv *wil,
 				       struct wil_tid_ampdu_rx *r,
 				       u16 hseq)
 {
 	int index;

 	/* note: this function is never called with
 	 * hseq preceding r->head_seq_num, i.e it is always true
 	 * !seq_less(hseq, r->head_seq_num)
 	 * and thus on loop exit it should be
 	 * r->head_seq_num == hseq
 	 */
 	while (seq_less(r->head_seq_num, hseq) && r->stored_mpdu_num) {
 		index = reorder_index(r, r->head_seq_num);
 		wil_release_reorder_frame(wil, r, index);
 	}
 	r->head_seq_num = hseq;
 }

 static void wil_reorder_release(struct wil6210_priv *wil,
 				struct wil_tid_ampdu_rx *r)
 {
 	int index = reorder_index(r, r->head_seq_num);

 	while (r->reorder_buf[index]) {
 		wil_release_reorder_frame(wil, r, index);
 		index = reorder_index(r, r->head_seq_num);
 	}
 }

 /* called in NAPI context */
 void wil_rx_reorder(struct wil6210_priv *wil, struct sk_buff *skb)
 __acquires(&sta->tid_rx_lock) __releases(&sta->tid_rx_lock)
 {
 	struct net_device *ndev = wil_to_ndev(wil);
 	struct vring_rx_desc *d = wil_skb_rxdesc(skb);
 	int tid = wil_rxdesc_tid(d);
 	int cid = wil_rxdesc_cid(d);
 	int mid = wil_rxdesc_mid(d);
 	u16 seq = wil_rxdesc_seq(d);
 	int mcast = wil_rxdesc_mcast(d);
 	struct wil_sta_info *sta = &wil->sta[cid];
 	struct wil_tid_ampdu_rx *r;
 	u16 hseq;
 	int index;

 	wil_dbg_txrx(wil, "MID %d CID %d TID %d Seq 0x%03x mcast %01x\n",
 		     mid, cid, tid, seq, mcast);

 	if (unlikely(mcast)) {
 		wil_netif_rx_any(skb, ndev);
 		return;
 	}

 	spin_lock(&sta->tid_rx_lock);

 	r = sta->tid_rx[tid];
 	if (!r) {
 		wil_netif_rx_any(skb, ndev);
 		goto out;
 	}

 	r->total++;
 	hseq = r->head_seq_num;

 	/** Due to the race between WMI events, where BACK establishment
 	 * reported, and data Rx, few packets may be pass up before reorder
 	 * buffer get allocated. Catch up by pretending SSN is what we
 	 * see in the 1-st Rx packet
 	 *
 	 * Another scenario, Rx get delayed and we got packet from before
 	 * BACK. Pass it to the stack and wait.
 	 */
 	if (r->first_time) {
 		r->first_time = false;
 		if (seq != r->head_seq_num) {
 			if (seq_less(seq, r->head_seq_num)) {
 				wil_err(wil,
 					"Error: frame with early sequence 0x%03x, should be 0x%03x. Waiting...\n",
 					seq, r->head_seq_num);
 				r->first_time = true;
 				wil_netif_rx_any(skb, ndev);
 				goto out;
 			}
 			wil_err(wil,
 				"Error: 1-st frame with wrong sequence 0x%03x, should be 0x%03x. Fixing...\n",
 				seq, r->head_seq_num);
 			r->head_seq_num = seq;
 			r->ssn = seq;
 		}
 	}

 	/* frame with out of date sequence number */
 	if (seq_less(seq, r->head_seq_num)) {
 		r->ssn_last_drop = seq;
 		r->drop_old++;
 		wil_dbg_txrx(wil, "Rx drop: old seq 0x%03x head 0x%03x\n",
 			     seq, r->head_seq_num);
 		dev_kfree_skb(skb);
 		goto out;
 	}

 	/*
 	 * If frame the sequence number exceeds our buffering window
 	 * size release some previous frames to make room for this one.
 	 */
 	if (!seq_less(seq, r->head_seq_num + r->buf_size)) {
 		hseq = seq_inc(seq_sub(seq, r->buf_size));
 		/* release stored frames up to new head to stack */
 		wil_release_reorder_frames(wil, r, hseq);
 	}

 	/* Now the new frame is always in the range of the reordering buffer */

 	index = reorder_index(r, seq);

 	/* check if we already stored this frame */
 	if (r->reorder_buf[index]) {
 		r->drop_dup++;
 		wil_dbg_txrx(wil, "Rx drop: dup seq 0x%03x\n", seq);
 		dev_kfree_skb(skb);
 		goto out;
 	}

 	/*
 	 * If the current MPDU is in the right order and nothing else
 	 * is stored we can process it directly, no need to buffer it.
 	 * If it is first but there's something stored, we may be able
 	 * to release frames after this one.
 	 */
 	if (seq == r->head_seq_num && r->stored_mpdu_num == 0) {
 		r->head_seq_num = seq_inc(r->head_seq_num);
 		wil_netif_rx_any(skb, ndev);
 		goto out;
 	}

 	/* put the frame in the reordering buffer */
 	r->reorder_buf[index] = skb;
 	r->reorder_time[index] = jiffies;
 	r->stored_mpdu_num++;
 	wil_reorder_release(wil, r);

 out:
 	spin_unlock(&sta->tid_rx_lock);
 }

 /* process BAR frame, called in NAPI context */
 void wil_rx_bar(struct wil6210_priv *wil, u8 cid, u8 tid, u16 seq)
 {
 	struct wil_sta_info *sta = &wil->sta[cid];
 	struct wil_tid_ampdu_rx *r;

 	spin_lock(&sta->tid_rx_lock);

 	r = sta->tid_rx[tid];
 	if (!r) {
 		wil_err(wil, "BAR for non-existing CID %d TID %d\n", cid, tid);
 		goto out;
 	}
 	if (seq_less(seq, r->head_seq_num)) {
 		wil_err(wil, "BAR Seq 0x%03x preceding head 0x%03x\n",
 			seq, r->head_seq_num);
 		goto out;
 	}
 	wil_dbg_txrx(wil, "BAR: CID %d TID %d Seq 0x%03x head 0x%03x\n",
 		     cid, tid, seq, r->head_seq_num);
 	wil_release_reorder_frames(wil, r, seq);

 out:
 	spin_unlock(&sta->tid_rx_lock);
 }

 struct wil_tid_ampdu_rx *wil_tid_ampdu_rx_alloc(struct wil6210_priv *wil,
 						int size, u16 ssn)
 {
 	struct wil_tid_ampdu_rx *r = kzalloc(sizeof(*r), GFP_KERNEL);

 	if (!r)
 		return NULL;

 	r->reorder_buf =
 		kcalloc(size, sizeof(struct sk_buff *), GFP_KERNEL);
 	r->reorder_time =
 		kcalloc(size, sizeof(unsigned long), GFP_KERNEL);
 	if (!r->reorder_buf || !r->reorder_time) {
 		kfree(r->reorder_buf);
 		kfree(r->reorder_time);
 		kfree(r);
 		return NULL;
 	}

 	r->ssn = ssn;
 	r->head_seq_num = ssn;
 	r->buf_size = size;
 	r->stored_mpdu_num = 0;
 	r->first_time = true;
 	return r;
 }

 void wil_tid_ampdu_rx_free(struct wil6210_priv *wil,
 			   struct wil_tid_ampdu_rx *r)
 {
 	int i;

 	if (!r)
 		return;

 	/* Do not pass remaining frames to the network stack - it may be
 	 * not expecting to get any more Rx. Rx from here may lead to
 	 * kernel OOPS since some per-socket accounting info was already
 	 * released.
 	 */
 	for (i = 0; i < r->buf_size; i++)
 		kfree_skb(r->reorder_buf[i]);

 	kfree(r->reorder_buf);
 	kfree(r->reorder_time);
 	kfree(r);
 }

 /* ADDBA processing */
 static u16 wil_agg_size(struct wil6210_priv *wil, u16 req_agg_wsize)
 {
 	u16 max_agg_size = min_t(u16, WIL_MAX_AGG_WSIZE, WIL_MAX_AMPDU_SIZE /
 				 (mtu_max + WIL_MAX_MPDU_OVERHEAD));

 	if (!req_agg_wsize)
 		return max_agg_size;

 	return min(max_agg_size, req_agg_wsize);
 }

 /* Block Ack - Rx side (recipient) */
 int wil_addba_rx_request(struct wil6210_priv *wil, u8 cidxtid,
 			 u8 dialog_token, __le16 ba_param_set,
 			 __le16 ba_timeout, __le16 ba_seq_ctrl)
 __acquires(&sta->tid_rx_lock) __releases(&sta->tid_rx_lock)
 {
 	u16 param_set = le16_to_cpu(ba_param_set);
 	u16 agg_timeout = le16_to_cpu(ba_timeout);
 	u16 seq_ctrl = le16_to_cpu(ba_seq_ctrl);
 	struct wil_sta_info *sta;
 	u8 cid, tid;
 	u16 agg_wsize = 0;
 	/* bit 0: A-MSDU supported
 	 * bit 1: policy (should be 0 for us)
 	 * bits 2..5: TID
 	 * bits 6..15: buffer size
 	 */
 	u16 req_agg_wsize = WIL_GET_BITS(param_set, 6, 15);
 	bool agg_amsdu = !!(param_set & BIT(0));
 	int ba_policy = param_set & BIT(1);
 	u16 status = WLAN_STATUS_SUCCESS;
 	u16 ssn = seq_ctrl >> 4;
 	struct wil_tid_ampdu_rx *r;
 	int rc = 0;

 	might_sleep();
 	parse_cidxtid(cidxtid, &cid, &tid);

 	/* sanity checks */
 	if (cid >= WIL6210_MAX_CID) {
 		wil_err(wil, "BACK: invalid CID %d\n", cid);
 		rc = -EINVAL;
 		goto out;
 	}

 	sta = &wil->sta[cid];
 	if (sta->status != wil_sta_connected) {
 		wil_err(wil, "BACK: CID %d not connected\n", cid);
 		rc = -EINVAL;
 		goto out;
 	}

 	wil_dbg_wmi(wil,
 		    "ADDBA request for CID %d %pM TID %d size %d timeout %d AMSDU%s policy %d token %d SSN 0x%03x\n",
 		    cid, sta->addr, tid, req_agg_wsize, agg_timeout,
 		    agg_amsdu ? "+" : "-", !!ba_policy, dialog_token, ssn);

 	/* apply policies */
 	if (ba_policy) {
 		wil_err(wil, "BACK requested unsupported ba_policy == 1\n");
 		status = WLAN_STATUS_INVALID_QOS_PARAM;
 	}
 	if (status == WLAN_STATUS_SUCCESS)
 		agg_wsize = wil_agg_size(wil, req_agg_wsize);

 	rc = wmi_addba_rx_resp(wil, cid, tid, dialog_token, status,
 			       agg_amsdu, agg_wsize, agg_timeout);
 	if (rc || (status != WLAN_STATUS_SUCCESS)) {
 		wil_err(wil, "%s: do not apply ba, rc(%d), status(%d)\n",
 			__func__, rc, status);
 		goto out;
 	}

 	/* apply */
 	r = wil_tid_ampdu_rx_alloc(wil, agg_wsize, ssn);
 	spin_lock_bh(&sta->tid_rx_lock);
 	wil_tid_ampdu_rx_free(wil, sta->tid_rx[tid]);
 	sta->tid_rx[tid] = r;
 	spin_unlock_bh(&sta->tid_rx_lock);

 out:
 	return rc;
 }

 /* BACK - Tx side (originator) */
 int wil_addba_tx_request(struct wil6210_priv *wil, u8 ringid, u16 wsize)
 {
 	u8 agg_wsize = wil_agg_size(wil, wsize);
 	u16 agg_timeout = 0;
 	struct vring_tx_data *txdata = &wil->vring_tx_data[ringid];
 	int rc = 0;

 	if (txdata->addba_in_progress) {
 		wil_dbg_misc(wil, "ADDBA for vring[%d] already in progress\n",
 			     ringid);
 		goto out;
 	}
 	if (txdata->agg_wsize) {
 		wil_dbg_misc(wil,
 			     "ADDBA for vring[%d] already done for wsize %d\n",
 			     ringid, txdata->agg_wsize);
 		goto out;
 	}
 	txdata->addba_in_progress = true;
 	rc = wmi_addba(wil, ringid, agg_wsize, agg_timeout);
 	if (rc) {
 		wil_err(wil, "%s: wmi_addba failed, rc (%d)", __func__, rc);
 		txdata->addba_in_progress = false;
 	}

 out:
 	return rc;
 }
	/*
	* Copyright (c) 2014-2016 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 "wil6210.h"
	#include "txrx.h"

	#define SEQ_MODULO 0x1000
	#define SEQ_MASK 0xfff

	static inline int seq_less(u16 sq1, u16 sq2)
	{
	return ((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1);
	}

	static inline u16 seq_inc(u16 sq)
	{
	return (sq + 1) & SEQ_MASK;
	}

	static inline u16 seq_sub(u16 sq1, u16 sq2)
	{
	return (sq1 - sq2) & SEQ_MASK;
	}

	static inline int reorder_index(struct wil_tid_ampdu_rx *r, u16 seq)
	{
	return seq_sub(seq, r->ssn) % r->buf_size;
	}

	static void wil_release_reorder_frame(struct wil6210_priv *wil,
	struct wil_tid_ampdu_rx *r,
	int index)
	{
	struct net_device *ndev = wil_to_ndev(wil);
	struct sk_buff *skb = r->reorder_buf[index];

	if (!skb)
	goto no_frame;

	/* release the frame from the reorder ring buffer */
	r->stored_mpdu_num--;
	r->reorder_buf[index] = NULL;
	wil_netif_rx_any(skb, ndev);

	no_frame:
	r->head_seq_num = seq_inc(r->head_seq_num);
	}

	static void wil_release_reorder_frames(struct wil6210_priv *wil,
	struct wil_tid_ampdu_rx *r,
	u16 hseq)
	{
	int index;

	/* note: this function is never called with
	* hseq preceding r->head_seq_num, i.e it is always true
	* !seq_less(hseq, r->head_seq_num)
	* and thus on loop exit it should be
	* r->head_seq_num == hseq
	*/
	while (seq_less(r->head_seq_num, hseq) && r->stored_mpdu_num) {
	index = reorder_index(r, r->head_seq_num);
	wil_release_reorder_frame(wil, r, index);
	}
	r->head_seq_num = hseq;
	}

	static void wil_reorder_release(struct wil6210_priv *wil,
	struct wil_tid_ampdu_rx *r)
	{
	int index = reorder_index(r, r->head_seq_num);

	while (r->reorder_buf[index]) {
	wil_release_reorder_frame(wil, r, index);
	index = reorder_index(r, r->head_seq_num);
	}
	}

	/* called in NAPI context */
	void wil_rx_reorder(struct wil6210_priv wil, struct sk_buff skb)
	__acquires(&sta->tid_rx_lock) __releases(&sta->tid_rx_lock)
	{
	struct net_device *ndev = wil_to_ndev(wil);
	struct vring_rx_desc *d = wil_skb_rxdesc(skb);
	int tid = wil_rxdesc_tid(d);
	int cid = wil_rxdesc_cid(d);
	int mid = wil_rxdesc_mid(d);
	u16 seq = wil_rxdesc_seq(d);
	int mcast = wil_rxdesc_mcast(d);
	struct wil_sta_info *sta = &wil->sta[cid];
	struct wil_tid_ampdu_rx *r;
	u16 hseq;
	int index;

	wil_dbg_txrx(wil, "MID %d CID %d TID %d Seq 0x%03x mcast %01x\n",
	mid, cid, tid, seq, mcast);

	if (unlikely(mcast)) {
	wil_netif_rx_any(skb, ndev);
	return;
	}

	spin_lock(&sta->tid_rx_lock);

	r = sta->tid_rx[tid];
	if (!r) {
	wil_netif_rx_any(skb, ndev);
	goto out;
	}

	r->total++;
	hseq = r->head_seq_num;

	/** Due to the race between WMI events, where BACK establishment
	* reported, and data Rx, few packets may be pass up before reorder
	* buffer get allocated. Catch up by pretending SSN is what we
	* see in the 1-st Rx packet
	*
	* Another scenario, Rx get delayed and we got packet from before
	* BACK. Pass it to the stack and wait.
	*/
	if (r->first_time) {
	r->first_time = false;
	if (seq != r->head_seq_num) {
	if (seq_less(seq, r->head_seq_num)) {
	wil_err(wil,
	"Error: frame with early sequence 0x%03x, should be 0x%03x. Waiting...\n",
	seq, r->head_seq_num);
	r->first_time = true;
	wil_netif_rx_any(skb, ndev);
	goto out;
	}
	wil_err(wil,
	"Error: 1-st frame with wrong sequence 0x%03x, should be 0x%03x. Fixing...\n",
	seq, r->head_seq_num);
	r->head_seq_num = seq;
	r->ssn = seq;
	}
	}

	/* frame with out of date sequence number */
	if (seq_less(seq, r->head_seq_num)) {
	r->ssn_last_drop = seq;
	r->drop_old++;
	wil_dbg_txrx(wil, "Rx drop: old seq 0x%03x head 0x%03x\n",
	seq, r->head_seq_num);
	dev_kfree_skb(skb);
	goto out;
	}

	/*
	* If frame the sequence number exceeds our buffering window
	* size release some previous frames to make room for this one.
	*/
	if (!seq_less(seq, r->head_seq_num + r->buf_size)) {
	hseq = seq_inc(seq_sub(seq, r->buf_size));
	/* release stored frames up to new head to stack */
	wil_release_reorder_frames(wil, r, hseq);
	}

	/* Now the new frame is always in the range of the reordering buffer */

	index = reorder_index(r, seq);

	/* check if we already stored this frame */
	if (r->reorder_buf[index]) {
	r->drop_dup++;
	wil_dbg_txrx(wil, "Rx drop: dup seq 0x%03x\n", seq);
	dev_kfree_skb(skb);
	goto out;
	}

	/*
	* If the current MPDU is in the right order and nothing else
	* is stored we can process it directly, no need to buffer it.
	* If it is first but there's something stored, we may be able
	* to release frames after this one.
	*/
	if (seq == r->head_seq_num && r->stored_mpdu_num == 0) {
	r->head_seq_num = seq_inc(r->head_seq_num);
	wil_netif_rx_any(skb, ndev);
	goto out;
	}

	/* put the frame in the reordering buffer */
	r->reorder_buf[index] = skb;
	r->reorder_time[index] = jiffies;
	r->stored_mpdu_num++;
	wil_reorder_release(wil, r);

	out:
	spin_unlock(&sta->tid_rx_lock);
	}

	/* process BAR frame, called in NAPI context */
	void wil_rx_bar(struct wil6210_priv *wil, u8 cid, u8 tid, u16 seq)
	{
	struct wil_sta_info *sta = &wil->sta[cid];
	struct wil_tid_ampdu_rx *r;

	spin_lock(&sta->tid_rx_lock);

	r = sta->tid_rx[tid];
	if (!r) {
	wil_err(wil, "BAR for non-existing CID %d TID %d\n", cid, tid);
	goto out;
	}
	if (seq_less(seq, r->head_seq_num)) {
	wil_err(wil, "BAR Seq 0x%03x preceding head 0x%03x\n",
	seq, r->head_seq_num);
	goto out;
	}
	wil_dbg_txrx(wil, "BAR: CID %d TID %d Seq 0x%03x head 0x%03x\n",
	cid, tid, seq, r->head_seq_num);
	wil_release_reorder_frames(wil, r, seq);

	out:
	spin_unlock(&sta->tid_rx_lock);
	}

	struct wil_tid_ampdu_rx wil_tid_ampdu_rx_alloc(struct wil6210_priv wil,
	int size, u16 ssn)
	{
	struct wil_tid_ampdu_rx r = kzalloc(sizeof(r), GFP_KERNEL);

	if (!r)
	return NULL;

	r->reorder_buf =
	kcalloc(size, sizeof(struct sk_buff *), GFP_KERNEL);
	r->reorder_time =
	kcalloc(size, sizeof(unsigned long), GFP_KERNEL);
	if (!r->reorder_buf \|\| !r->reorder_time) {
	kfree(r->reorder_buf);
	kfree(r->reorder_time);
	kfree(r);
	return NULL;
	}

	r->ssn = ssn;
	r->head_seq_num = ssn;
	r->buf_size = size;
	r->stored_mpdu_num = 0;
	r->first_time = true;
	return r;
	}

	void wil_tid_ampdu_rx_free(struct wil6210_priv *wil,
	struct wil_tid_ampdu_rx *r)
	{
	int i;

	if (!r)
	return;

	/* Do not pass remaining frames to the network stack - it may be
	* not expecting to get any more Rx. Rx from here may lead to
	* kernel OOPS since some per-socket accounting info was already
	* released.
	*/
	for (i = 0; i < r->buf_size; i++)
	kfree_skb(r->reorder_buf[i]);

	kfree(r->reorder_buf);
	kfree(r->reorder_time);
	kfree(r);
	}

	/* ADDBA processing */
	static u16 wil_agg_size(struct wil6210_priv *wil, u16 req_agg_wsize)
	{
	u16 max_agg_size = min_t(u16, WIL_MAX_AGG_WSIZE, WIL_MAX_AMPDU_SIZE /
	(mtu_max + WIL_MAX_MPDU_OVERHEAD));

	if (!req_agg_wsize)
	return max_agg_size;

	return min(max_agg_size, req_agg_wsize);
	}

	/* Block Ack - Rx side (recipient) */
	int wil_addba_rx_request(struct wil6210_priv *wil, u8 cidxtid,
	u8 dialog_token, __le16 ba_param_set,
	__le16 ba_timeout, __le16 ba_seq_ctrl)
	__acquires(&sta->tid_rx_lock) __releases(&sta->tid_rx_lock)
	{
	u16 param_set = le16_to_cpu(ba_param_set);
	u16 agg_timeout = le16_to_cpu(ba_timeout);
	u16 seq_ctrl = le16_to_cpu(ba_seq_ctrl);
	struct wil_sta_info *sta;
	u8 cid, tid;
	u16 agg_wsize = 0;
	/* bit 0: A-MSDU supported
	* bit 1: policy (should be 0 for us)
	* bits 2..5: TID
	* bits 6..15: buffer size
	*/
	u16 req_agg_wsize = WIL_GET_BITS(param_set, 6, 15);
	bool agg_amsdu = !!(param_set & BIT(0));
	int ba_policy = param_set & BIT(1);
	u16 status = WLAN_STATUS_SUCCESS;
	u16 ssn = seq_ctrl >> 4;
	struct wil_tid_ampdu_rx *r;
	int rc = 0;

	might_sleep();
	parse_cidxtid(cidxtid, &cid, &tid);

	/* sanity checks */
	if (cid >= WIL6210_MAX_CID) {
	wil_err(wil, "BACK: invalid CID %d\n", cid);
	rc = -EINVAL;
	goto out;
	}

	sta = &wil->sta[cid];
	if (sta->status != wil_sta_connected) {
	wil_err(wil, "BACK: CID %d not connected\n", cid);
	rc = -EINVAL;
	goto out;
	}

	wil_dbg_wmi(wil,
	"ADDBA request for CID %d %pM TID %d size %d timeout %d AMSDU%s policy %d token %d SSN 0x%03x\n",
	cid, sta->addr, tid, req_agg_wsize, agg_timeout,
	agg_amsdu ? "+" : "-", !!ba_policy, dialog_token, ssn);

	/* apply policies */
	if (ba_policy) {
	wil_err(wil, "BACK requested unsupported ba_policy == 1\n");
	status = WLAN_STATUS_INVALID_QOS_PARAM;
	}
	if (status == WLAN_STATUS_SUCCESS)
	agg_wsize = wil_agg_size(wil, req_agg_wsize);

	rc = wmi_addba_rx_resp(wil, cid, tid, dialog_token, status,
	agg_amsdu, agg_wsize, agg_timeout);
	if (rc \|\| (status != WLAN_STATUS_SUCCESS)) {
	wil_err(wil, "%s: do not apply ba, rc(%d), status(%d)\n",
	__func__, rc, status);
	goto out;
	}

	/* apply */
	r = wil_tid_ampdu_rx_alloc(wil, agg_wsize, ssn);
	spin_lock_bh(&sta->tid_rx_lock);
	wil_tid_ampdu_rx_free(wil, sta->tid_rx[tid]);
	sta->tid_rx[tid] = r;
	spin_unlock_bh(&sta->tid_rx_lock);

	out:
	return rc;
	}

	/* BACK - Tx side (originator) */
	int wil_addba_tx_request(struct wil6210_priv *wil, u8 ringid, u16 wsize)
	{
	u8 agg_wsize = wil_agg_size(wil, wsize);
	u16 agg_timeout = 0;
	struct vring_tx_data *txdata = &wil->vring_tx_data[ringid];
	int rc = 0;

	if (txdata->addba_in_progress) {
	wil_dbg_misc(wil, "ADDBA for vring[%d] already in progress\n",
	ringid);
	goto out;
	}
	if (txdata->agg_wsize) {
	wil_dbg_misc(wil,
	"ADDBA for vring[%d] already done for wsize %d\n",
	ringid, txdata->agg_wsize);
	goto out;
	}
	txdata->addba_in_progress = true;
	rc = wmi_addba(wil, ringid, agg_wsize, agg_timeout);
	if (rc) {
	wil_err(wil, "%s: wmi_addba failed, rc (%d)", __func__, rc);
	txdata->addba_in_progress = false;
	}

	out:
	return rc;
	}