// SPDX-License-Identifier: BSD-3-Clause-Clear
/* 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;
        if (sdio->pse_mcu_quota_max &&
            sdio->sched.pse_mcu_quota > sdio->pse_mcu_quota_max) {
                sdio->sched.pse_mcu_quota = sdio->pse_mcu_quota_max;
        }
        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);
                atomic_set(&dev->bus_hung, true);
                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);
                atomic_set(&dev->bus_hung, true);
        }
        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 = __skb_grow(e->skb, roundup(e->skb->len,
                                                         sdio->func->cur_blksize));
                        if (err)
                                return err;
                        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);