text: /*
  
    Broadcom B43 wireless driver
  
    PIO data transfer
  
    Copyright (c) 2005-2008 Michael Buesch <m@bues.ch>
  
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.
  
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
  
    You should have received a copy of the GNU General Public License
    along with this program; see the file COPYING.  If not, write to
    the Free Software Foundation, Inc., 51 Franklin Steet, Fifth Floor,
    Boston, MA 02110-1301, USA.
  
  */
  
  #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(sizeof(*q), GFP_KERNEL);
  	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(sizeof(*q), GFP_KERNEL);
  	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) {
  			dev_kfree_skb_any(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;
  		ieee80211_stop_queue(dev->wl->hw, 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. */
  		dev_kfree_skb_any(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. */
  		ieee80211_stop_queue(dev->wl->hw, 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(dev->wl->hw, pack->skb);
  	pack->skb = NULL;
  	list_add(&pack->list, &q->packets_list);
  
  	if (q->stopped) {
  		ieee80211_wake_queue(dev->wl->hw, 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 0;
  		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 0;
  		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 1;
  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 1;
  
  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 1;
  }
  
  void b43_pio_rx(struct b43_pio_rxqueue *q)
  {
  	unsigned int count = 0;
  	bool stop;
  
  	while (1) {
  		stop = (pio_rx_frame(q) == 0);
  		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);
  }
  