/*
 * Copyright (C) 2018 Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
 *
 * 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 "mt76x02.h"

static void mt76x02u_remove_dma_hdr(struct sk_buff *skb)
{
	int hdr_len;

	skb_pull(skb, sizeof(struct mt76x02_txwi) + MT_DMA_HDR_LEN);
	hdr_len = ieee80211_get_hdrlen_from_skb(skb);
	if (hdr_len % 4)
		mt76x02_remove_hdr_pad(skb, 2);
}

void mt76x02u_tx_complete_skb(struct mt76_dev *mdev, struct mt76_queue *q,
			      struct mt76_queue_entry *e, bool flush)
{
	mt76x02u_remove_dma_hdr(e->skb);
	mt76_tx_complete_skb(mdev, e->skb);
}
EXPORT_SYMBOL_GPL(mt76x02u_tx_complete_skb);

int mt76x02u_skb_dma_info(struct sk_buff *skb, int port, u32 flags)
{
	struct sk_buff *iter, *last = skb;
	u32 info, pad;

	/* Buffer layout:
	 *	|   4B   | xfer len |      pad       |  4B  |
	 *	| TXINFO | pkt/cmd  | zero pad to 4B | zero |
	 *
	 * length field of TXINFO should be set to 'xfer len'.
	 */
	info = FIELD_PREP(MT_TXD_INFO_LEN, round_up(skb->len, 4)) |
	       FIELD_PREP(MT_TXD_INFO_DPORT, port) | flags;
	put_unaligned_le32(info, skb_push(skb, sizeof(info)));

	/* Add zero pad of 4 - 7 bytes */
	pad = round_up(skb->len, 4) + 4 - skb->len;

	/* First packet of a A-MSDU burst keeps track of the whole burst
	 * length, need to update lenght of it and the last packet.
	 */
	skb_walk_frags(skb, iter) {
		last = iter;
		if (!iter->next) {
			skb->data_len += pad;
			skb->len += pad;
			break;
		}
	}

	if (skb_pad(last, pad))
		return -ENOMEM;
	__skb_put(last, pad);

	return 0;
}

int mt76x02u_tx_prepare_skb(struct mt76_dev *mdev, void *data,
			    struct sk_buff *skb, struct mt76_queue *q,
			    struct mt76_wcid *wcid, struct ieee80211_sta *sta,
			    u32 *tx_info)
{
	struct mt76x02_dev *dev = container_of(mdev, struct mt76x02_dev, mt76);
	struct mt76x02_txwi *txwi;
	enum mt76_qsel qsel;
	int len = skb->len;
	u32 flags;
	int pid;

	mt76x02_insert_hdr_pad(skb);

	txwi = (struct mt76x02_txwi *)(skb->data - sizeof(struct mt76x02_txwi));
	mt76x02_mac_write_txwi(dev, txwi, skb, wcid, sta, len);
	skb_push(skb, sizeof(struct mt76x02_txwi));

	pid = mt76_tx_status_skb_add(mdev, wcid, skb);
	txwi->pktid = pid;

	if (pid >= MT_PACKET_ID_FIRST || q2ep(q->hw_idx) == MT_EP_OUT_HCCA)
		qsel = MT_QSEL_MGMT;
	else
		qsel = MT_QSEL_EDCA;

	flags = FIELD_PREP(MT_TXD_INFO_QSEL, qsel) |
		MT_TXD_INFO_80211;
	if (!wcid || wcid->hw_key_idx == 0xff || wcid->sw_iv)
		flags |= MT_TXD_INFO_WIV;

	return mt76x02u_skb_dma_info(skb, WLAN_PORT, flags);
}
EXPORT_SYMBOL_GPL(mt76x02u_tx_prepare_skb);