// SPDX-License-Identifier: ISC
/* Copyright (C) 2020 MediaTek Inc.
 *
 * Author: Felix Fietkau <nbd@nbd.name>
 *	   Lorenzo Bianconi <lorenzo@kernel.org>
 *	   Sean Wang <sean.wang@mediatek.com>
 */

#include <linux/kernel.h>
#include <linux/iopoll.h>
#include <linux/module.h>

#include <linux/mmc/host.h>
#include <linux/mmc/sdio_ids.h>
#include <linux/mmc/sdio_func.h>

#include "trace.h"
#include "sdio.h"
#include "mt76.h"

static int mt76s_refill_sched_quota(struct mt76_dev *dev, u32 *data)
{
	u32 ple_ac_data_quota[] = {
		FIELD_GET(TXQ_CNT_L, data[4]), /* VO */
		FIELD_GET(TXQ_CNT_H, data[3]), /* VI */
		FIELD_GET(TXQ_CNT_L, data[3]), /* BE */
		FIELD_GET(TXQ_CNT_H, data[2]), /* BK */
	};
	u32 pse_ac_data_quota[] = {
		FIELD_GET(TXQ_CNT_H, data[1]), /* VO */
		FIELD_GET(TXQ_CNT_L, data[1]), /* VI */
		FIELD_GET(TXQ_CNT_H, data[0]), /* BE */
		FIELD_GET(TXQ_CNT_L, data[0]), /* BK */
	};
	u32 pse_mcu_quota = FIELD_GET(TXQ_CNT_L, data[2]);
	u32 pse_data_quota = 0, ple_data_quota = 0;
	struct mt76_sdio *sdio = &dev->sdio;
	int i;

	for (i = 0; i < ARRAY_SIZE(pse_ac_data_quota); i++) {
		pse_data_quota += pse_ac_data_quota[i];
		ple_data_quota += ple_ac_data_quota[i];
	}

	if (!pse_data_quota && !ple_data_quota && !pse_mcu_quota)
		return 0;

	sdio->sched.pse_mcu_quota += pse_mcu_quota;
	sdio->sched.pse_data_quota += pse_data_quota;
	sdio->sched.ple_data_quota += ple_data_quota;

	return pse_data_quota + ple_data_quota + pse_mcu_quota;
}

static struct sk_buff *
mt76s_build_rx_skb(void *data, int data_len, int buf_len)
{
	int len = min_t(int, data_len, MT_SKB_HEAD_LEN);
	struct sk_buff *skb;

	skb = alloc_skb(len, GFP_KERNEL);
	if (!skb)
		return NULL;

	skb_put_data(skb, data, len);
	if (data_len > len) {
		struct page *page;

		data += len;
		page = virt_to_head_page(data);
		skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
				page, data - page_address(page),
				data_len - len, buf_len);
		get_page(page);
	}

	return skb;
}

static int
mt76s_rx_run_queue(struct mt76_dev *dev, enum mt76_rxq_id qid,
		   struct mt76s_intr *intr)
{
	struct mt76_queue *q = &dev->q_rx[qid];
	struct mt76_sdio *sdio = &dev->sdio;
	int len = 0, err, i;
	struct page *page;
	u8 *buf, *end;

	for (i = 0; i < intr->rx.num[qid]; i++)
		len += round_up(intr->rx.len[qid][i] + 4, 4);

	if (!len)
		return 0;

	if (len > sdio->func->cur_blksize)
		len = roundup(len, sdio->func->cur_blksize);

	page = __dev_alloc_pages(GFP_KERNEL, get_order(len));
	if (!page)
		return -ENOMEM;

	buf = page_address(page);

	sdio_claim_host(sdio->func);
	err = sdio_readsb(sdio->func, buf, MCR_WRDR(qid), len);
	sdio_release_host(sdio->func);

	if (err < 0) {
		dev_err(dev->dev, "sdio read data failed:%d\n", err);
		put_page(page);
		return err;
	}

	end = buf + len;
	i = 0;

	while (i < intr->rx.num[qid] && buf < end) {
		int index = (q->head + i) % q->ndesc;
		struct mt76_queue_entry *e = &q->entry[index];
		__le32 *rxd = (__le32 *)buf;

		/* parse rxd to get the actual packet length */
		len = le32_get_bits(rxd[0], GENMASK(15, 0));

		/* Optimized path for TXS */
		if (!dev->drv->rx_check || dev->drv->rx_check(dev, buf, len)) {
			e->skb = mt76s_build_rx_skb(buf, len,
						    round_up(len + 4, 4));
			if (!e->skb)
				break;

			if (q->queued + i + 1 == q->ndesc)
				break;
			i++;
		}
		buf += round_up(len + 4, 4);
	}
	put_page(page);

	spin_lock_bh(&q->lock);
	q->head = (q->head + i) % q->ndesc;
	q->queued += i;
	spin_unlock_bh(&q->lock);

	return i;
}

static int mt76s_rx_handler(struct mt76_dev *dev)
{
	struct mt76_sdio *sdio = &dev->sdio;
	struct mt76s_intr intr;
	int nframes = 0, ret;

	ret = sdio->parse_irq(dev, &intr);
	if (ret)
		return ret;

	trace_dev_irq(dev, intr.isr, 0);

	if (intr.isr & WHIER_RX0_DONE_INT_EN) {
		ret = mt76s_rx_run_queue(dev, 0, &intr);
		if (ret > 0) {
			mt76_worker_schedule(&sdio->net_worker);
			nframes += ret;
		}
	}

	if (intr.isr & WHIER_RX1_DONE_INT_EN) {
		ret = mt76s_rx_run_queue(dev, 1, &intr);
		if (ret > 0) {
			mt76_worker_schedule(&sdio->net_worker);
			nframes += ret;
		}
	}

	nframes += !!mt76s_refill_sched_quota(dev, intr.tx.wtqcr);

	return nframes;
}

static int
mt76s_tx_pick_quota(struct mt76_sdio *sdio, bool mcu, int buf_sz,
		    int *pse_size, int *ple_size)
{
	int pse_sz;

	pse_sz = DIV_ROUND_UP(buf_sz + sdio->sched.deficit,
			      sdio->sched.pse_page_size);

	if (mcu && sdio->hw_ver == MT76_CONNAC2_SDIO)
		pse_sz = 1;

	if (mcu) {
		if (sdio->sched.pse_mcu_quota < *pse_size + pse_sz)
			return -EBUSY;
	} else {
		if (sdio->sched.pse_data_quota < *pse_size + pse_sz ||
		    sdio->sched.ple_data_quota < *ple_size + 1)
			return -EBUSY;

		*ple_size = *ple_size + 1;
	}
	*pse_size = *pse_size + pse_sz;

	return 0;
}

static void
mt76s_tx_update_quota(struct mt76_sdio *sdio, bool mcu, int pse_size,
		      int ple_size)
{
	if (mcu) {
		sdio->sched.pse_mcu_quota -= pse_size;
	} else {
		sdio->sched.pse_data_quota -= pse_size;
		sdio->sched.ple_data_quota -= ple_size;
	}
}

static int __mt76s_xmit_queue(struct mt76_dev *dev, u8 *data, int len)
{
	struct mt76_sdio *sdio = &dev->sdio;
	int err;

	if (len > sdio->func->cur_blksize)
		len = roundup(len, sdio->func->cur_blksize);

	sdio_claim_host(sdio->func);
	err = sdio_writesb(sdio->func, MCR_WTDR1, data, len);
	sdio_release_host(sdio->func);

	if (err)
		dev_err(dev->dev, "sdio write failed: %d\n", err);

	return err;
}

static int mt76s_tx_run_queue(struct mt76_dev *dev, struct mt76_queue *q)
{
	int err, nframes = 0, len = 0, pse_sz = 0, ple_sz = 0;
	bool mcu = q == dev->q_mcu[MT_MCUQ_WM];
	struct mt76_sdio *sdio = &dev->sdio;
	u8 pad;

	while (q->first != q->head) {
		struct mt76_queue_entry *e = &q->entry[q->first];
		struct sk_buff *iter;

		smp_rmb();

		if (test_bit(MT76_MCU_RESET, &dev->phy.state))
			goto next;

		if (!test_bit(MT76_STATE_MCU_RUNNING, &dev->phy.state)) {
			__skb_put_zero(e->skb, 4);
			err = __mt76s_xmit_queue(dev, e->skb->data,
						 e->skb->len);
			if (err)
				return err;

			goto next;
		}

		pad = roundup(e->skb->len, 4) - e->skb->len;
		if (len + e->skb->len + pad + 4 > dev->sdio.xmit_buf_sz)
			break;

		if (mt76s_tx_pick_quota(sdio, mcu, e->buf_sz, &pse_sz,
					&ple_sz))
			break;

		memcpy(sdio->xmit_buf + len, e->skb->data, skb_headlen(e->skb));
		len += skb_headlen(e->skb);
		nframes++;

		skb_walk_frags(e->skb, iter) {
			memcpy(sdio->xmit_buf + len, iter->data, iter->len);
			len += iter->len;
			nframes++;
		}

		if (unlikely(pad)) {
			memset(sdio->xmit_buf + len, 0, pad);
			len += pad;
		}
next:
		q->first = (q->first + 1) % q->ndesc;
		e->done = true;
	}

	if (nframes) {
		memset(sdio->xmit_buf + len, 0, 4);
		err = __mt76s_xmit_queue(dev, sdio->xmit_buf, len + 4);
		if (err)
			return err;
	}
	mt76s_tx_update_quota(sdio, mcu, pse_sz, ple_sz);

	mt76_worker_schedule(&sdio->status_worker);

	return nframes;
}

void mt76s_txrx_worker(struct mt76_sdio *sdio)
{
	struct mt76_dev *dev = container_of(sdio, struct mt76_dev, sdio);
	int i, nframes, ret;

	/* disable interrupt */
	sdio_claim_host(sdio->func);
	sdio_writel(sdio->func, WHLPCR_INT_EN_CLR, MCR_WHLPCR, NULL);
	sdio_release_host(sdio->func);

	do {
		nframes = 0;

		/* tx */
		for (i = 0; i <= MT_TXQ_PSD; i++) {
			ret = mt76s_tx_run_queue(dev, dev->phy.q_tx[i]);
			if (ret > 0)
				nframes += ret;
		}
		ret = mt76s_tx_run_queue(dev, dev->q_mcu[MT_MCUQ_WM]);
		if (ret > 0)
			nframes += ret;

		/* rx */
		ret = mt76s_rx_handler(dev);
		if (ret > 0)
			nframes += ret;

		if (test_bit(MT76_MCU_RESET, &dev->phy.state) ||
		    test_bit(MT76_STATE_SUSPEND, &dev->phy.state)) {
			if (!mt76s_txqs_empty(dev))
				continue;
			else
				wake_up(&sdio->wait);
		}
	} while (nframes > 0);

	/* enable interrupt */
	sdio_claim_host(sdio->func);
	sdio_writel(sdio->func, WHLPCR_INT_EN_SET, MCR_WHLPCR, NULL);
	sdio_release_host(sdio->func);
}
EXPORT_SYMBOL_GPL(mt76s_txrx_worker);

void mt76s_sdio_irq(struct sdio_func *func)
{
	struct mt76_dev *dev = sdio_get_drvdata(func);
	struct mt76_sdio *sdio = &dev->sdio;

	if (!test_bit(MT76_STATE_INITIALIZED, &dev->phy.state) ||
	    test_bit(MT76_MCU_RESET, &dev->phy.state))
		return;

	sdio_writel(sdio->func, WHLPCR_INT_EN_CLR, MCR_WHLPCR, NULL);
	mt76_worker_schedule(&sdio->txrx_worker);
}
EXPORT_SYMBOL_GPL(mt76s_sdio_irq);

bool mt76s_txqs_empty(struct mt76_dev *dev)
{
	struct mt76_queue *q;
	int i;

	for (i = 0; i <= MT_TXQ_PSD + 1; i++) {
		if (i <= MT_TXQ_PSD)
			q = dev->phy.q_tx[i];
		else
			q = dev->q_mcu[MT_MCUQ_WM];

		if (q->first != q->head)
			return false;
	}

	return true;
}
EXPORT_SYMBOL_GPL(mt76s_txqs_empty);