// SPDX-License-Identifier: GPL-2.0-or-later
/*

  Broadcom B43 wireless driver

  PIO data transfer

  Copyright (c) 2005-2008 Michael Buesch <m@bues.ch>


*/

#include "b43.h"
#include "pio.h"
#include "dma.h"
#include "main.h"
#include "xmit.h"

#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/slab.h>


static u16 generate_cookie(struct b43_pio_txqueue *q,
                           struct b43_pio_txpacket *pack)
{
        u16 cookie;

        /* Use the upper 4 bits of the cookie as
         * PIO controller ID and store the packet index number
         * in the lower 12 bits.
         * Note that the cookie must never be 0, as this
         * is a special value used in RX path.
         * It can also not be 0xFFFF because that is special
         * for multicast frames.
         */
        cookie = (((u16)q->index + 1) << 12);
        cookie |= pack->index;

        return cookie;
}

static
struct b43_pio_txqueue *parse_cookie(struct b43_wldev *dev,
                                     u16 cookie,
                                      struct b43_pio_txpacket **pack)
{
        struct b43_pio *pio = &dev->pio;
        struct b43_pio_txqueue *q = NULL;
        unsigned int pack_index;

        switch (cookie & 0xF000) {
        case 0x1000:
                q = pio->tx_queue_AC_BK;
                break;
        case 0x2000:
                q = pio->tx_queue_AC_BE;
                break;
        case 0x3000:
                q = pio->tx_queue_AC_VI;
                break;
        case 0x4000:
                q = pio->tx_queue_AC_VO;
                break;
        case 0x5000:
                q = pio->tx_queue_mcast;
                break;
        }
        if (B43_WARN_ON(!q))
                return NULL;
        pack_index = (cookie & 0x0FFF);
        if (B43_WARN_ON(pack_index >= ARRAY_SIZE(q->packets)))
                return NULL;
        *pack = &q->packets[pack_index];

        return q;
}

static u16 index_to_pioqueue_base(struct b43_wldev *dev,
                                  unsigned int index)
{
        static const u16 bases[] = {
                B43_MMIO_PIO_BASE0,
                B43_MMIO_PIO_BASE1,
                B43_MMIO_PIO_BASE2,
                B43_MMIO_PIO_BASE3,
                B43_MMIO_PIO_BASE4,
                B43_MMIO_PIO_BASE5,
                B43_MMIO_PIO_BASE6,
                B43_MMIO_PIO_BASE7,
        };
        static const u16 bases_rev11[] = {
                B43_MMIO_PIO11_BASE0,
                B43_MMIO_PIO11_BASE1,
                B43_MMIO_PIO11_BASE2,
                B43_MMIO_PIO11_BASE3,
                B43_MMIO_PIO11_BASE4,
                B43_MMIO_PIO11_BASE5,
        };

        if (dev->dev->core_rev >= 11) {
                B43_WARN_ON(index >= ARRAY_SIZE(bases_rev11));
                return bases_rev11[index];
        }
        B43_WARN_ON(index >= ARRAY_SIZE(bases));
        return bases[index];
}

static u16 pio_txqueue_offset(struct b43_wldev *dev)
{
        if (dev->dev->core_rev >= 11)
                return 0x18;
        return 0;
}

static u16 pio_rxqueue_offset(struct b43_wldev *dev)
{
        if (dev->dev->core_rev >= 11)
                return 0x38;
        return 8;
}

static struct b43_pio_txqueue *b43_setup_pioqueue_tx(struct b43_wldev *dev,
                                                     unsigned int index)
{
        struct b43_pio_txqueue *q;
        struct b43_pio_txpacket *p;
        unsigned int i;

        q = kzalloc_obj(*q);
        if (!q)
                return NULL;
        q->dev = dev;
        q->rev = dev->dev->core_rev;
        q->mmio_base = index_to_pioqueue_base(dev, index) +
                       pio_txqueue_offset(dev);
        q->index = index;

        q->free_packet_slots = B43_PIO_MAX_NR_TXPACKETS;
        if (q->rev >= 8) {
                q->buffer_size = 1920; //FIXME this constant is wrong.
        } else {
                q->buffer_size = b43_piotx_read16(q, B43_PIO_TXQBUFSIZE);
                q->buffer_size -= 80;
        }

        INIT_LIST_HEAD(&q->packets_list);
        for (i = 0; i < ARRAY_SIZE(q->packets); i++) {
                p = &(q->packets[i]);
                INIT_LIST_HEAD(&p->list);
                p->index = i;
                p->queue = q;
                list_add(&p->list, &q->packets_list);
        }

        return q;
}

static struct b43_pio_rxqueue *b43_setup_pioqueue_rx(struct b43_wldev *dev,
                                                     unsigned int index)
{
        struct b43_pio_rxqueue *q;

        q = kzalloc_obj(*q);
        if (!q)
                return NULL;
        q->dev = dev;
        q->rev = dev->dev->core_rev;
        q->mmio_base = index_to_pioqueue_base(dev, index) +
                       pio_rxqueue_offset(dev);

        /* Enable Direct FIFO RX (PIO) on the engine. */
        b43_dma_direct_fifo_rx(dev, index, 1);

        return q;
}

static void b43_pio_cancel_tx_packets(struct b43_pio_txqueue *q)
{
        struct b43_pio_txpacket *pack;
        unsigned int i;

        for (i = 0; i < ARRAY_SIZE(q->packets); i++) {
                pack = &(q->packets[i]);
                if (pack->skb) {
                        ieee80211_free_txskb(q->dev->wl->hw, pack->skb);
                        pack->skb = NULL;
                }
        }
}

static void b43_destroy_pioqueue_tx(struct b43_pio_txqueue *q,
                                    const char *name)
{
        if (!q)
                return;
        b43_pio_cancel_tx_packets(q);
        kfree(q);
}

static void b43_destroy_pioqueue_rx(struct b43_pio_rxqueue *q,
                                    const char *name)
{
        if (!q)
                return;
        kfree(q);
}

#define destroy_queue_tx(pio, queue) do {                               \
        b43_destroy_pioqueue_tx((pio)->queue, __stringify(queue));      \
        (pio)->queue = NULL;                                            \
  } while (0)

#define destroy_queue_rx(pio, queue) do {                               \
        b43_destroy_pioqueue_rx((pio)->queue, __stringify(queue));      \
        (pio)->queue = NULL;                                            \
  } while (0)

void b43_pio_free(struct b43_wldev *dev)
{
        struct b43_pio *pio;

        if (!b43_using_pio_transfers(dev))
                return;
        pio = &dev->pio;

        destroy_queue_rx(pio, rx_queue);
        destroy_queue_tx(pio, tx_queue_mcast);
        destroy_queue_tx(pio, tx_queue_AC_VO);
        destroy_queue_tx(pio, tx_queue_AC_VI);
        destroy_queue_tx(pio, tx_queue_AC_BE);
        destroy_queue_tx(pio, tx_queue_AC_BK);
}

int b43_pio_init(struct b43_wldev *dev)
{
        struct b43_pio *pio = &dev->pio;
        int err = -ENOMEM;

        b43_write32(dev, B43_MMIO_MACCTL, b43_read32(dev, B43_MMIO_MACCTL)
                    & ~B43_MACCTL_BE);
        b43_shm_write16(dev, B43_SHM_SHARED, B43_SHM_SH_RXPADOFF, 0);

        pio->tx_queue_AC_BK = b43_setup_pioqueue_tx(dev, 0);
        if (!pio->tx_queue_AC_BK)
                goto out;

        pio->tx_queue_AC_BE = b43_setup_pioqueue_tx(dev, 1);
        if (!pio->tx_queue_AC_BE)
                goto err_destroy_bk;

        pio->tx_queue_AC_VI = b43_setup_pioqueue_tx(dev, 2);
        if (!pio->tx_queue_AC_VI)
                goto err_destroy_be;

        pio->tx_queue_AC_VO = b43_setup_pioqueue_tx(dev, 3);
        if (!pio->tx_queue_AC_VO)
                goto err_destroy_vi;

        pio->tx_queue_mcast = b43_setup_pioqueue_tx(dev, 4);
        if (!pio->tx_queue_mcast)
                goto err_destroy_vo;

        pio->rx_queue = b43_setup_pioqueue_rx(dev, 0);
        if (!pio->rx_queue)
                goto err_destroy_mcast;

        b43dbg(dev->wl, "PIO initialized\n");
        err = 0;
out:
        return err;

err_destroy_mcast:
        destroy_queue_tx(pio, tx_queue_mcast);
err_destroy_vo:
        destroy_queue_tx(pio, tx_queue_AC_VO);
err_destroy_vi:
        destroy_queue_tx(pio, tx_queue_AC_VI);
err_destroy_be:
        destroy_queue_tx(pio, tx_queue_AC_BE);
err_destroy_bk:
        destroy_queue_tx(pio, tx_queue_AC_BK);
        return err;
}

/* Static mapping of mac80211's queues (priorities) to b43 PIO queues. */
static struct b43_pio_txqueue *select_queue_by_priority(struct b43_wldev *dev,
                                                        u8 queue_prio)
{
        struct b43_pio_txqueue *q;

        if (dev->qos_enabled) {
                /* 0 = highest priority */
                switch (queue_prio) {
                default:
                        B43_WARN_ON(1);
                        fallthrough;
                case 0:
                        q = dev->pio.tx_queue_AC_VO;
                        break;
                case 1:
                        q = dev->pio.tx_queue_AC_VI;
                        break;
                case 2:
                        q = dev->pio.tx_queue_AC_BE;
                        break;
                case 3:
                        q = dev->pio.tx_queue_AC_BK;
                        break;
                }
        } else
                q = dev->pio.tx_queue_AC_BE;

        return q;
}

static u16 tx_write_2byte_queue(struct b43_pio_txqueue *q,
                                u16 ctl,
                                const void *_data,
                                unsigned int data_len)
{
        struct b43_wldev *dev = q->dev;
        struct b43_wl *wl = dev->wl;
        const u8 *data = _data;

        ctl |= B43_PIO_TXCTL_WRITELO | B43_PIO_TXCTL_WRITEHI;
        b43_piotx_write16(q, B43_PIO_TXCTL, ctl);

        b43_block_write(dev, data, (data_len & ~1),
                        q->mmio_base + B43_PIO_TXDATA,
                        sizeof(u16));
        if (data_len & 1) {
                u8 *tail = wl->pio_tailspace;
                BUILD_BUG_ON(sizeof(wl->pio_tailspace) < 2);

                /* Write the last byte. */
                ctl &= ~B43_PIO_TXCTL_WRITEHI;
                b43_piotx_write16(q, B43_PIO_TXCTL, ctl);
                tail[0] = data[data_len - 1];
                tail[1] = 0;
                b43_block_write(dev, tail, 2,
                                q->mmio_base + B43_PIO_TXDATA,
                                sizeof(u16));
        }

        return ctl;
}

static void pio_tx_frame_2byte_queue(struct b43_pio_txpacket *pack,
                                     const u8 *hdr, unsigned int hdrlen)
{
        struct b43_pio_txqueue *q = pack->queue;
        const char *frame = pack->skb->data;
        unsigned int frame_len = pack->skb->len;
        u16 ctl;

        ctl = b43_piotx_read16(q, B43_PIO_TXCTL);
        ctl |= B43_PIO_TXCTL_FREADY;
        ctl &= ~B43_PIO_TXCTL_EOF;

        /* Transfer the header data. */
        ctl = tx_write_2byte_queue(q, ctl, hdr, hdrlen);
        /* Transfer the frame data. */
        ctl = tx_write_2byte_queue(q, ctl, frame, frame_len);

        ctl |= B43_PIO_TXCTL_EOF;
        b43_piotx_write16(q, B43_PIO_TXCTL, ctl);
}

static u32 tx_write_4byte_queue(struct b43_pio_txqueue *q,
                                u32 ctl,
                                const void *_data,
                                unsigned int data_len)
{
        struct b43_wldev *dev = q->dev;
        struct b43_wl *wl = dev->wl;
        const u8 *data = _data;

        ctl |= B43_PIO8_TXCTL_0_7 | B43_PIO8_TXCTL_8_15 |
               B43_PIO8_TXCTL_16_23 | B43_PIO8_TXCTL_24_31;
        b43_piotx_write32(q, B43_PIO8_TXCTL, ctl);

        b43_block_write(dev, data, (data_len & ~3),
                        q->mmio_base + B43_PIO8_TXDATA,
                        sizeof(u32));
        if (data_len & 3) {
                u8 *tail = wl->pio_tailspace;
                BUILD_BUG_ON(sizeof(wl->pio_tailspace) < 4);

                memset(tail, 0, 4);
                /* Write the last few bytes. */
                ctl &= ~(B43_PIO8_TXCTL_8_15 | B43_PIO8_TXCTL_16_23 |
                         B43_PIO8_TXCTL_24_31);
                switch (data_len & 3) {
                case 3:
                        ctl |= B43_PIO8_TXCTL_16_23 | B43_PIO8_TXCTL_8_15;
                        tail[0] = data[data_len - 3];
                        tail[1] = data[data_len - 2];
                        tail[2] = data[data_len - 1];
                        break;
                case 2:
                        ctl |= B43_PIO8_TXCTL_8_15;
                        tail[0] = data[data_len - 2];
                        tail[1] = data[data_len - 1];
                        break;
                case 1:
                        tail[0] = data[data_len - 1];
                        break;
                }
                b43_piotx_write32(q, B43_PIO8_TXCTL, ctl);
                b43_block_write(dev, tail, 4,
                                q->mmio_base + B43_PIO8_TXDATA,
                                sizeof(u32));
        }

        return ctl;
}

static void pio_tx_frame_4byte_queue(struct b43_pio_txpacket *pack,
                                     const u8 *hdr, unsigned int hdrlen)
{
        struct b43_pio_txqueue *q = pack->queue;
        const char *frame = pack->skb->data;
        unsigned int frame_len = pack->skb->len;
        u32 ctl;

        ctl = b43_piotx_read32(q, B43_PIO8_TXCTL);
        ctl |= B43_PIO8_TXCTL_FREADY;
        ctl &= ~B43_PIO8_TXCTL_EOF;

        /* Transfer the header data. */
        ctl = tx_write_4byte_queue(q, ctl, hdr, hdrlen);
        /* Transfer the frame data. */
        ctl = tx_write_4byte_queue(q, ctl, frame, frame_len);

        ctl |= B43_PIO8_TXCTL_EOF;
        b43_piotx_write32(q, B43_PIO_TXCTL, ctl);
}

static int pio_tx_frame(struct b43_pio_txqueue *q,
                        struct sk_buff *skb)
{
        struct b43_wldev *dev = q->dev;
        struct b43_wl *wl = dev->wl;
        struct b43_pio_txpacket *pack;
        u16 cookie;
        int err;
        unsigned int hdrlen;
        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
        struct b43_txhdr *txhdr = (struct b43_txhdr *)wl->pio_scratchspace;

        B43_WARN_ON(list_empty(&q->packets_list));
        pack = list_entry(q->packets_list.next,
                          struct b43_pio_txpacket, list);

        cookie = generate_cookie(q, pack);
        hdrlen = b43_txhdr_size(dev);
        BUILD_BUG_ON(sizeof(wl->pio_scratchspace) < sizeof(struct b43_txhdr));
        B43_WARN_ON(sizeof(wl->pio_scratchspace) < hdrlen);
        err = b43_generate_txhdr(dev, (u8 *)txhdr, skb,
                                 info, cookie);
        if (err)
                return err;

        if (info->flags & IEEE80211_TX_CTL_SEND_AFTER_DTIM) {
                /* Tell the firmware about the cookie of the last
                 * mcast frame, so it can clear the more-data bit in it. */
                b43_shm_write16(dev, B43_SHM_SHARED,
                                B43_SHM_SH_MCASTCOOKIE, cookie);
        }

        pack->skb = skb;
        if (q->rev >= 8)
                pio_tx_frame_4byte_queue(pack, (const u8 *)txhdr, hdrlen);
        else
                pio_tx_frame_2byte_queue(pack, (const u8 *)txhdr, hdrlen);

        /* Remove it from the list of available packet slots.
         * It will be put back when we receive the status report. */
        list_del(&pack->list);

        /* Update the queue statistics. */
        q->buffer_used += roundup(skb->len + hdrlen, 4);
        q->free_packet_slots -= 1;

        return 0;
}

int b43_pio_tx(struct b43_wldev *dev, struct sk_buff *skb)
{
        struct b43_pio_txqueue *q;
        struct ieee80211_hdr *hdr;
        unsigned int hdrlen, total_len;
        int err = 0;
        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);

        hdr = (struct ieee80211_hdr *)skb->data;

        if (info->flags & IEEE80211_TX_CTL_SEND_AFTER_DTIM) {
                /* The multicast queue will be sent after the DTIM. */
                q = dev->pio.tx_queue_mcast;
                /* Set the frame More-Data bit. Ucode will clear it
                 * for us on the last frame. */
                hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA);
        } else {
                /* Decide by priority where to put this frame. */
                q = select_queue_by_priority(dev, skb_get_queue_mapping(skb));
        }

        hdrlen = b43_txhdr_size(dev);
        total_len = roundup(skb->len + hdrlen, 4);

        if (unlikely(total_len > q->buffer_size)) {
                err = -ENOBUFS;
                b43dbg(dev->wl, "PIO: TX packet longer than queue.\n");
                goto out;
        }
        if (unlikely(q->free_packet_slots == 0)) {
                err = -ENOBUFS;
                b43warn(dev->wl, "PIO: TX packet overflow.\n");
                goto out;
        }
        B43_WARN_ON(q->buffer_used > q->buffer_size);

        if (total_len > (q->buffer_size - q->buffer_used)) {
                /* Not enough memory on the queue. */
                err = -EBUSY;
                b43_stop_queue(dev, skb_get_queue_mapping(skb));
                q->stopped = true;
                goto out;
        }

        /* Assign the queue number to the ring (if not already done before)
         * so TX status handling can use it. The mac80211-queue to b43-queue
         * mapping is static, so we don't need to store it per frame. */
        q->queue_prio = skb_get_queue_mapping(skb);

        err = pio_tx_frame(q, skb);
        if (unlikely(err == -ENOKEY)) {
                /* Drop this packet, as we don't have the encryption key
                 * anymore and must not transmit it unencrypted. */
                ieee80211_free_txskb(dev->wl->hw, skb);
                err = 0;
                goto out;
        }
        if (unlikely(err)) {
                b43err(dev->wl, "PIO transmission failure\n");
                goto out;
        }

        B43_WARN_ON(q->buffer_used > q->buffer_size);
        if (((q->buffer_size - q->buffer_used) < roundup(2 + 2 + 6, 4)) ||
            (q->free_packet_slots == 0)) {
                /* The queue is full. */
                b43_stop_queue(dev, skb_get_queue_mapping(skb));
                q->stopped = true;
        }

out:
        return err;
}

void b43_pio_handle_txstatus(struct b43_wldev *dev,
                             const struct b43_txstatus *status)
{
        struct b43_pio_txqueue *q;
        struct b43_pio_txpacket *pack = NULL;
        unsigned int total_len;
        struct ieee80211_tx_info *info;

        q = parse_cookie(dev, status->cookie, &pack);
        if (unlikely(!q))
                return;
        B43_WARN_ON(!pack);

        info = IEEE80211_SKB_CB(pack->skb);

        b43_fill_txstatus_report(dev, info, status);

        total_len = pack->skb->len + b43_txhdr_size(dev);
        total_len = roundup(total_len, 4);
        q->buffer_used -= total_len;
        q->free_packet_slots += 1;

        ieee80211_tx_status_skb(dev->wl->hw, pack->skb);
        pack->skb = NULL;
        list_add(&pack->list, &q->packets_list);

        if (q->stopped) {
                b43_wake_queue(dev, q->queue_prio);
                q->stopped = false;
        }
}

/* Returns whether we should fetch another frame. */
static bool pio_rx_frame(struct b43_pio_rxqueue *q)
{
        struct b43_wldev *dev = q->dev;
        struct b43_wl *wl = dev->wl;
        u16 len;
        u32 macstat = 0;
        unsigned int i, padding;
        struct sk_buff *skb;
        const char *err_msg = NULL;
        struct b43_rxhdr_fw4 *rxhdr =
                (struct b43_rxhdr_fw4 *)wl->pio_scratchspace;
        size_t rxhdr_size = sizeof(*rxhdr);

        BUILD_BUG_ON(sizeof(wl->pio_scratchspace) < sizeof(*rxhdr));
        switch (dev->fw.hdr_format) {
        case B43_FW_HDR_410:
        case B43_FW_HDR_351:
                rxhdr_size -= sizeof(rxhdr->format_598) -
                        sizeof(rxhdr->format_351);
                break;
        case B43_FW_HDR_598:
                break;
        }
        memset(rxhdr, 0, rxhdr_size);

        /* Check if we have data and wait for it to get ready. */
        if (q->rev >= 8) {
                u32 ctl;

                ctl = b43_piorx_read32(q, B43_PIO8_RXCTL);
                if (!(ctl & B43_PIO8_RXCTL_FRAMERDY))
                        return false;
                b43_piorx_write32(q, B43_PIO8_RXCTL,
                                  B43_PIO8_RXCTL_FRAMERDY);
                for (i = 0; i < 10; i++) {
                        ctl = b43_piorx_read32(q, B43_PIO8_RXCTL);
                        if (ctl & B43_PIO8_RXCTL_DATARDY)
                                goto data_ready;
                        udelay(10);
                }
        } else {
                u16 ctl;

                ctl = b43_piorx_read16(q, B43_PIO_RXCTL);
                if (!(ctl & B43_PIO_RXCTL_FRAMERDY))
                        return false;
                b43_piorx_write16(q, B43_PIO_RXCTL,
                                  B43_PIO_RXCTL_FRAMERDY);
                for (i = 0; i < 10; i++) {
                        ctl = b43_piorx_read16(q, B43_PIO_RXCTL);
                        if (ctl & B43_PIO_RXCTL_DATARDY)
                                goto data_ready;
                        udelay(10);
                }
        }
        b43dbg(q->dev->wl, "PIO RX timed out\n");
        return true;
data_ready:

        /* Get the preamble (RX header) */
        if (q->rev >= 8) {
                b43_block_read(dev, rxhdr, rxhdr_size,
                               q->mmio_base + B43_PIO8_RXDATA,
                               sizeof(u32));
        } else {
                b43_block_read(dev, rxhdr, rxhdr_size,
                               q->mmio_base + B43_PIO_RXDATA,
                               sizeof(u16));
        }
        /* Sanity checks. */
        len = le16_to_cpu(rxhdr->frame_len);
        if (unlikely(len > 0x700)) {
                err_msg = "len > 0x700";
                goto rx_error;
        }
        if (unlikely(len == 0)) {
                err_msg = "len == 0";
                goto rx_error;
        }

        switch (dev->fw.hdr_format) {
        case B43_FW_HDR_598:
                macstat = le32_to_cpu(rxhdr->format_598.mac_status);
                break;
        case B43_FW_HDR_410:
        case B43_FW_HDR_351:
                macstat = le32_to_cpu(rxhdr->format_351.mac_status);
                break;
        }
        if (macstat & B43_RX_MAC_FCSERR) {
                if (!(q->dev->wl->filter_flags & FIF_FCSFAIL)) {
                        /* Drop frames with failed FCS. */
                        err_msg = "Frame FCS error";
                        goto rx_error;
                }
        }

        /* We always pad 2 bytes, as that's what upstream code expects
         * due to the RX-header being 30 bytes. In case the frame is
         * unaligned, we pad another 2 bytes. */
        padding = (macstat & B43_RX_MAC_PADDING) ? 2 : 0;
        skb = dev_alloc_skb(len + padding + 2);
        if (unlikely(!skb)) {
                err_msg = "Out of memory";
                goto rx_error;
        }
        skb_reserve(skb, 2);
        skb_put(skb, len + padding);
        if (q->rev >= 8) {
                b43_block_read(dev, skb->data + padding, (len & ~3),
                               q->mmio_base + B43_PIO8_RXDATA,
                               sizeof(u32));
                if (len & 3) {
                        u8 *tail = wl->pio_tailspace;
                        BUILD_BUG_ON(sizeof(wl->pio_tailspace) < 4);

                        /* Read the last few bytes. */
                        b43_block_read(dev, tail, 4,
                                       q->mmio_base + B43_PIO8_RXDATA,
                                       sizeof(u32));
                        switch (len & 3) {
                        case 3:
                                skb->data[len + padding - 3] = tail[0];
                                skb->data[len + padding - 2] = tail[1];
                                skb->data[len + padding - 1] = tail[2];
                                break;
                        case 2:
                                skb->data[len + padding - 2] = tail[0];
                                skb->data[len + padding - 1] = tail[1];
                                break;
                        case 1:
                                skb->data[len + padding - 1] = tail[0];
                                break;
                        }
                }
        } else {
                b43_block_read(dev, skb->data + padding, (len & ~1),
                               q->mmio_base + B43_PIO_RXDATA,
                               sizeof(u16));
                if (len & 1) {
                        u8 *tail = wl->pio_tailspace;
                        BUILD_BUG_ON(sizeof(wl->pio_tailspace) < 2);

                        /* Read the last byte. */
                        b43_block_read(dev, tail, 2,
                                       q->mmio_base + B43_PIO_RXDATA,
                                       sizeof(u16));
                        skb->data[len + padding - 1] = tail[0];
                }
        }

        b43_rx(q->dev, skb, rxhdr);

        return true;

rx_error:
        if (err_msg)
                b43dbg(q->dev->wl, "PIO RX error: %s\n", err_msg);
        if (q->rev >= 8)
                b43_piorx_write32(q, B43_PIO8_RXCTL, B43_PIO8_RXCTL_DATARDY);
        else
                b43_piorx_write16(q, B43_PIO_RXCTL, B43_PIO_RXCTL_DATARDY);

        return true;
}

void b43_pio_rx(struct b43_pio_rxqueue *q)
{
        unsigned int count = 0;
        bool stop;

        while (1) {
                stop = !pio_rx_frame(q);
                if (stop)
                        break;
                cond_resched();
                if (WARN_ON_ONCE(++count > 10000))
                        break;
        }
}

static void b43_pio_tx_suspend_queue(struct b43_pio_txqueue *q)
{
        if (q->rev >= 8) {
                b43_piotx_write32(q, B43_PIO8_TXCTL,
                                  b43_piotx_read32(q, B43_PIO8_TXCTL)
                                  | B43_PIO8_TXCTL_SUSPREQ);
        } else {
                b43_piotx_write16(q, B43_PIO_TXCTL,
                                  b43_piotx_read16(q, B43_PIO_TXCTL)
                                  | B43_PIO_TXCTL_SUSPREQ);
        }
}

static void b43_pio_tx_resume_queue(struct b43_pio_txqueue *q)
{
        if (q->rev >= 8) {
                b43_piotx_write32(q, B43_PIO8_TXCTL,
                                  b43_piotx_read32(q, B43_PIO8_TXCTL)
                                  & ~B43_PIO8_TXCTL_SUSPREQ);
        } else {
                b43_piotx_write16(q, B43_PIO_TXCTL,
                                  b43_piotx_read16(q, B43_PIO_TXCTL)
                                  & ~B43_PIO_TXCTL_SUSPREQ);
        }
}

void b43_pio_tx_suspend(struct b43_wldev *dev)
{
        b43_power_saving_ctl_bits(dev, B43_PS_AWAKE);
        b43_pio_tx_suspend_queue(dev->pio.tx_queue_AC_BK);
        b43_pio_tx_suspend_queue(dev->pio.tx_queue_AC_BE);
        b43_pio_tx_suspend_queue(dev->pio.tx_queue_AC_VI);
        b43_pio_tx_suspend_queue(dev->pio.tx_queue_AC_VO);
        b43_pio_tx_suspend_queue(dev->pio.tx_queue_mcast);
}

void b43_pio_tx_resume(struct b43_wldev *dev)
{
        b43_pio_tx_resume_queue(dev->pio.tx_queue_mcast);
        b43_pio_tx_resume_queue(dev->pio.tx_queue_AC_VO);
        b43_pio_tx_resume_queue(dev->pio.tx_queue_AC_VI);
        b43_pio_tx_resume_queue(dev->pio.tx_queue_AC_BE);
        b43_pio_tx_resume_queue(dev->pio.tx_queue_AC_BK);
        b43_power_saving_ctl_bits(dev, 0);
}