[B43]: add mac80211-based driver for modern BCM43xx devices

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1494 insertions, 0 deletions

diff --git a/drivers/net/wireless/b43/dma.c b/drivers/net/wireless/b43/dma.c
new file mode 100644
index 00000000000..5e8f8ac0f1d
--- /dev/null
+++ b/drivers/net/wireless/b43/dma.c
@@ -0,0 +1,1494 @@
+/*
+
+  Broadcom B43 wireless driver
+
+  DMA ringbuffer and descriptor allocation/management
+
+  Copyright (c) 2005, 2006 Michael Buesch <mb@bu3sch.de>
+
+  Some code in this file is derived from the b44.c driver
+  Copyright (C) 2002 David S. Miller
+  Copyright (C) Pekka Pietikainen
+
+  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 "dma.h"
+#include "main.h"
+#include "debugfs.h"
+#include "xmit.h"
+
+#include <linux/dma-mapping.h>
+#include <linux/pci.h>
+#include <linux/delay.h>
+#include <linux/skbuff.h>
+
+/* 32bit DMA ops. */
+static
+struct b43_dmadesc_generic *op32_idx2desc(struct b43_dmaring *ring,
+					  int slot,
+					  struct b43_dmadesc_meta **meta)
+{
+	struct b43_dmadesc32 *desc;
+
+	*meta = &(ring->meta[slot]);
+	desc = ring->descbase;
+	desc = &(desc[slot]);
+
+	return (struct b43_dmadesc_generic *)desc;
+}
+
+static void op32_fill_descriptor(struct b43_dmaring *ring,
+				 struct b43_dmadesc_generic *desc,
+				 dma_addr_t dmaaddr, u16 bufsize,
+				 int start, int end, int irq)
+{
+	struct b43_dmadesc32 *descbase = ring->descbase;
+	int slot;
+	u32 ctl;
+	u32 addr;
+	u32 addrext;
+
+	slot = (int)(&(desc->dma32) - descbase);
+	B43_WARN_ON(!(slot >= 0 && slot < ring->nr_slots));
+
+	addr = (u32) (dmaaddr & ~SSB_DMA_TRANSLATION_MASK);
+	addrext = (u32) (dmaaddr & SSB_DMA_TRANSLATION_MASK)
+	    >> SSB_DMA_TRANSLATION_SHIFT;
+	addr |= ssb_dma_translation(ring->dev->dev);
+	ctl = (bufsize - ring->frameoffset)
+	    & B43_DMA32_DCTL_BYTECNT;
+	if (slot == ring->nr_slots - 1)
+		ctl |= B43_DMA32_DCTL_DTABLEEND;
+	if (start)
+		ctl |= B43_DMA32_DCTL_FRAMESTART;
+	if (end)
+		ctl |= B43_DMA32_DCTL_FRAMEEND;
+	if (irq)
+		ctl |= B43_DMA32_DCTL_IRQ;
+	ctl |= (addrext << B43_DMA32_DCTL_ADDREXT_SHIFT)
+	    & B43_DMA32_DCTL_ADDREXT_MASK;
+
+	desc->dma32.control = cpu_to_le32(ctl);
+	desc->dma32.address = cpu_to_le32(addr);
+}
+
+static void op32_poke_tx(struct b43_dmaring *ring, int slot)
+{
+	b43_dma_write(ring, B43_DMA32_TXINDEX,
+		      (u32) (slot * sizeof(struct b43_dmadesc32)));
+}
+
+static void op32_tx_suspend(struct b43_dmaring *ring)
+{
+	b43_dma_write(ring, B43_DMA32_TXCTL, b43_dma_read(ring, B43_DMA32_TXCTL)
+		      | B43_DMA32_TXSUSPEND);
+}
+
+static void op32_tx_resume(struct b43_dmaring *ring)
+{
+	b43_dma_write(ring, B43_DMA32_TXCTL, b43_dma_read(ring, B43_DMA32_TXCTL)
+		      & ~B43_DMA32_TXSUSPEND);
+}
+
+static int op32_get_current_rxslot(struct b43_dmaring *ring)
+{
+	u32 val;
+
+	val = b43_dma_read(ring, B43_DMA32_RXSTATUS);
+	val &= B43_DMA32_RXDPTR;
+
+	return (val / sizeof(struct b43_dmadesc32));
+}
+
+static void op32_set_current_rxslot(struct b43_dmaring *ring, int slot)
+{
+	b43_dma_write(ring, B43_DMA32_RXINDEX,
+		      (u32) (slot * sizeof(struct b43_dmadesc32)));
+}
+
+static const struct b43_dma_ops dma32_ops = {
+	.idx2desc = op32_idx2desc,
+	.fill_descriptor = op32_fill_descriptor,
+	.poke_tx = op32_poke_tx,
+	.tx_suspend = op32_tx_suspend,
+	.tx_resume = op32_tx_resume,
+	.get_current_rxslot = op32_get_current_rxslot,
+	.set_current_rxslot = op32_set_current_rxslot,
+};
+
+/* 64bit DMA ops. */
+static
+struct b43_dmadesc_generic *op64_idx2desc(struct b43_dmaring *ring,
+					  int slot,
+					  struct b43_dmadesc_meta **meta)
+{
+	struct b43_dmadesc64 *desc;
+
+	*meta = &(ring->meta[slot]);
+	desc = ring->descbase;
+	desc = &(desc[slot]);
+
+	return (struct b43_dmadesc_generic *)desc;
+}
+
+static void op64_fill_descriptor(struct b43_dmaring *ring,
+				 struct b43_dmadesc_generic *desc,
+				 dma_addr_t dmaaddr, u16 bufsize,
+				 int start, int end, int irq)
+{
+	struct b43_dmadesc64 *descbase = ring->descbase;
+	int slot;
+	u32 ctl0 = 0, ctl1 = 0;
+	u32 addrlo, addrhi;
+	u32 addrext;
+
+	slot = (int)(&(desc->dma64) - descbase);
+	B43_WARN_ON(!(slot >= 0 && slot < ring->nr_slots));
+
+	addrlo = (u32) (dmaaddr & 0xFFFFFFFF);
+	addrhi = (((u64) dmaaddr >> 32) & ~SSB_DMA_TRANSLATION_MASK);
+	addrext = (((u64) dmaaddr >> 32) & SSB_DMA_TRANSLATION_MASK)
+	    >> SSB_DMA_TRANSLATION_SHIFT;
+	addrhi |= ssb_dma_translation(ring->dev->dev);
+	if (slot == ring->nr_slots - 1)
+		ctl0 |= B43_DMA64_DCTL0_DTABLEEND;
+	if (start)
+		ctl0 |= B43_DMA64_DCTL0_FRAMESTART;
+	if (end)
+		ctl0 |= B43_DMA64_DCTL0_FRAMEEND;
+	if (irq)
+		ctl0 |= B43_DMA64_DCTL0_IRQ;
+	ctl1 |= (bufsize - ring->frameoffset)
+	    & B43_DMA64_DCTL1_BYTECNT;
+	ctl1 |= (addrext << B43_DMA64_DCTL1_ADDREXT_SHIFT)
+	    & B43_DMA64_DCTL1_ADDREXT_MASK;
+
+	desc->dma64.control0 = cpu_to_le32(ctl0);
+	desc->dma64.control1 = cpu_to_le32(ctl1);
+	desc->dma64.address_low = cpu_to_le32(addrlo);
+	desc->dma64.address_high = cpu_to_le32(addrhi);
+}
+
+static void op64_poke_tx(struct b43_dmaring *ring, int slot)
+{
+	b43_dma_write(ring, B43_DMA64_TXINDEX,
+		      (u32) (slot * sizeof(struct b43_dmadesc64)));
+}
+
+static void op64_tx_suspend(struct b43_dmaring *ring)
+{
+	b43_dma_write(ring, B43_DMA64_TXCTL, b43_dma_read(ring, B43_DMA64_TXCTL)
+		      | B43_DMA64_TXSUSPEND);
+}
+
+static void op64_tx_resume(struct b43_dmaring *ring)
+{
+	b43_dma_write(ring, B43_DMA64_TXCTL, b43_dma_read(ring, B43_DMA64_TXCTL)
+		      & ~B43_DMA64_TXSUSPEND);
+}
+
+static int op64_get_current_rxslot(struct b43_dmaring *ring)
+{
+	u32 val;
+
+	val = b43_dma_read(ring, B43_DMA64_RXSTATUS);
+	val &= B43_DMA64_RXSTATDPTR;
+
+	return (val / sizeof(struct b43_dmadesc64));
+}
+
+static void op64_set_current_rxslot(struct b43_dmaring *ring, int slot)
+{
+	b43_dma_write(ring, B43_DMA64_RXINDEX,
+		      (u32) (slot * sizeof(struct b43_dmadesc64)));
+}
+
+static const struct b43_dma_ops dma64_ops = {
+	.idx2desc = op64_idx2desc,
+	.fill_descriptor = op64_fill_descriptor,
+	.poke_tx = op64_poke_tx,
+	.tx_suspend = op64_tx_suspend,
+	.tx_resume = op64_tx_resume,
+	.get_current_rxslot = op64_get_current_rxslot,
+	.set_current_rxslot = op64_set_current_rxslot,
+};
+
+static inline int free_slots(struct b43_dmaring *ring)
+{
+	return (ring->nr_slots - ring->used_slots);
+}
+
+static inline int next_slot(struct b43_dmaring *ring, int slot)
+{
+	B43_WARN_ON(!(slot >= -1 && slot <= ring->nr_slots - 1));
+	if (slot == ring->nr_slots - 1)
+		return 0;
+	return slot + 1;
+}
+
+static inline int prev_slot(struct b43_dmaring *ring, int slot)
+{
+	B43_WARN_ON(!(slot >= 0 && slot <= ring->nr_slots - 1));
+	if (slot == 0)
+		return ring->nr_slots - 1;
+	return slot - 1;
+}
+
+#ifdef CONFIG_B43_DEBUG
+static void update_max_used_slots(struct b43_dmaring *ring,
+				  int current_used_slots)
+{
+	if (current_used_slots <= ring->max_used_slots)
+		return;
+	ring->max_used_slots = current_used_slots;
+	if (b43_debug(ring->dev, B43_DBG_DMAVERBOSE)) {
+		b43dbg(ring->dev->wl,
+		       "max_used_slots increased to %d on %s ring %d\n",
+		       ring->max_used_slots,
+		       ring->tx ? "TX" : "RX", ring->index);
+	}
+}
+#else
+static inline
+    void update_max_used_slots(struct b43_dmaring *ring, int current_used_slots)
+{
+}
+#endif /* DEBUG */
+
+/* Request a slot for usage. */
+static inline int request_slot(struct b43_dmaring *ring)
+{
+	int slot;
+
+	B43_WARN_ON(!ring->tx);
+	B43_WARN_ON(ring->stopped);
+	B43_WARN_ON(free_slots(ring) == 0);
+
+	slot = next_slot(ring, ring->current_slot);
+	ring->current_slot = slot;
+	ring->used_slots++;
+
+	update_max_used_slots(ring, ring->used_slots);
+
+	return slot;
+}
+
+/* Mac80211-queue to b43-ring mapping */
+static struct b43_dmaring *priority_to_txring(struct b43_wldev *dev,
+					      int queue_priority)
+{
+	struct b43_dmaring *ring;
+
+/*FIXME: For now we always run on TX-ring-1 */
+	return dev->dma.tx_ring1;
+
+	/* 0 = highest priority */
+	switch (queue_priority) {
+	default:
+		B43_WARN_ON(1);
+		/* fallthrough */
+	case 0:
+		ring = dev->dma.tx_ring3;
+		break;
+	case 1:
+		ring = dev->dma.tx_ring2;
+		break;
+	case 2:
+		ring = dev->dma.tx_ring1;
+		break;
+	case 3:
+		ring = dev->dma.tx_ring0;
+		break;
+	case 4:
+		ring = dev->dma.tx_ring4;
+		break;
+	case 5:
+		ring = dev->dma.tx_ring5;
+		break;
+	}
+
+	return ring;
+}
+
+/* Bcm43xx-ring to mac80211-queue mapping */
+static inline int txring_to_priority(struct b43_dmaring *ring)
+{
+	static const u8 idx_to_prio[] = { 3, 2, 1, 0, 4, 5, };
+
+/*FIXME: have only one queue, for now */
+	return 0;
+
+	return idx_to_prio[ring->index];
+}
+
+u16 b43_dmacontroller_base(int dma64bit, int controller_idx)
+{
+	static const u16 map64[] = {
+		B43_MMIO_DMA64_BASE0,
+		B43_MMIO_DMA64_BASE1,
+		B43_MMIO_DMA64_BASE2,
+		B43_MMIO_DMA64_BASE3,
+		B43_MMIO_DMA64_BASE4,
+		B43_MMIO_DMA64_BASE5,
+	};
+	static const u16 map32[] = {
+		B43_MMIO_DMA32_BASE0,
+		B43_MMIO_DMA32_BASE1,
+		B43_MMIO_DMA32_BASE2,
+		B43_MMIO_DMA32_BASE3,
+		B43_MMIO_DMA32_BASE4,
+		B43_MMIO_DMA32_BASE5,
+	};
+
+	if (dma64bit) {
+		B43_WARN_ON(!(controller_idx >= 0 &&
+			      controller_idx < ARRAY_SIZE(map64)));
+		return map64[controller_idx];
+	}
+	B43_WARN_ON(!(controller_idx >= 0 &&
+		      controller_idx < ARRAY_SIZE(map32)));
+	return map32[controller_idx];
+}
+
+static inline
+    dma_addr_t map_descbuffer(struct b43_dmaring *ring,
+			      unsigned char *buf, size_t len, int tx)
+{
+	dma_addr_t dmaaddr;
+
+	if (tx) {
+		dmaaddr = dma_map_single(ring->dev->dev->dev,
+					 buf, len, DMA_TO_DEVICE);
+	} else {
+		dmaaddr = dma_map_single(ring->dev->dev->dev,
+					 buf, len, DMA_FROM_DEVICE);
+	}
+
+	return dmaaddr;
+}
+
+static inline
+    void unmap_descbuffer(struct b43_dmaring *ring,
+			  dma_addr_t addr, size_t len, int tx)
+{
+	if (tx) {
+		dma_unmap_single(ring->dev->dev->dev, addr, len, DMA_TO_DEVICE);
+	} else {
+		dma_unmap_single(ring->dev->dev->dev,
+				 addr, len, DMA_FROM_DEVICE);
+	}
+}
+
+static inline
+    void sync_descbuffer_for_cpu(struct b43_dmaring *ring,
+				 dma_addr_t addr, size_t len)
+{
+	B43_WARN_ON(ring->tx);
+	dma_sync_single_for_cpu(ring->dev->dev->dev,
+				addr, len, DMA_FROM_DEVICE);
+}
+
+static inline
+    void sync_descbuffer_for_device(struct b43_dmaring *ring,
+				    dma_addr_t addr, size_t len)
+{
+	B43_WARN_ON(ring->tx);
+	dma_sync_single_for_device(ring->dev->dev->dev,
+				   addr, len, DMA_FROM_DEVICE);
+}
+
+static inline
+    void free_descriptor_buffer(struct b43_dmaring *ring,
+				struct b43_dmadesc_meta *meta)
+{
+	if (meta->skb) {
+		dev_kfree_skb_any(meta->skb);
+		meta->skb = NULL;
+	}
+}
+
+static int alloc_ringmemory(struct b43_dmaring *ring)
+{
+	struct device *dev = ring->dev->dev->dev;
+
+	ring->descbase = dma_alloc_coherent(dev, B43_DMA_RINGMEMSIZE,
+					    &(ring->dmabase), GFP_KERNEL);
+	if (!ring->descbase) {
+		b43err(ring->dev->wl, "DMA ringmemory allocation failed\n");
+		return -ENOMEM;
+	}
+	memset(ring->descbase, 0, B43_DMA_RINGMEMSIZE);
+
+	return 0;
+}
+
+static void free_ringmemory(struct b43_dmaring *ring)
+{
+	struct device *dev = ring->dev->dev->dev;
+
+	dma_free_coherent(dev, B43_DMA_RINGMEMSIZE,
+			  ring->descbase, ring->dmabase);
+}
+
+/* Reset the RX DMA channel */
+int b43_dmacontroller_rx_reset(struct b43_wldev *dev, u16 mmio_base, int dma64)
+{
+	int i;
+	u32 value;
+	u16 offset;
+
+	might_sleep();
+
+	offset = dma64 ? B43_DMA64_RXCTL : B43_DMA32_RXCTL;
+	b43_write32(dev, mmio_base + offset, 0);
+	for (i = 0; i < 10; i++) {
+		offset = dma64 ? B43_DMA64_RXSTATUS : B43_DMA32_RXSTATUS;
+		value = b43_read32(dev, mmio_base + offset);
+		if (dma64) {
+			value &= B43_DMA64_RXSTAT;
+			if (value == B43_DMA64_RXSTAT_DISABLED) {
+				i = -1;
+				break;
+			}
+		} else {
+			value &= B43_DMA32_RXSTATE;
+			if (value == B43_DMA32_RXSTAT_DISABLED) {
+				i = -1;
+				break;
+			}
+		}
+		msleep(1);
+	}
+	if (i != -1) {
+		b43err(dev->wl, "DMA RX reset timed out\n");
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+/* Reset the RX DMA channel */
+int b43_dmacontroller_tx_reset(struct b43_wldev *dev, u16 mmio_base, int dma64)
+{
+	int i;
+	u32 value;
+	u16 offset;
+
+	might_sleep();
+
+	for (i = 0; i < 10; i++) {
+		offset = dma64 ? B43_DMA64_TXSTATUS : B43_DMA32_TXSTATUS;
+		value = b43_read32(dev, mmio_base + offset);
+		if (dma64) {
+			value &= B43_DMA64_TXSTAT;
+			if (value == B43_DMA64_TXSTAT_DISABLED ||
+			    value == B43_DMA64_TXSTAT_IDLEWAIT ||
+			    value == B43_DMA64_TXSTAT_STOPPED)
+				break;
+		} else {
+			value &= B43_DMA32_TXSTATE;
+			if (value == B43_DMA32_TXSTAT_DISABLED ||
+			    value == B43_DMA32_TXSTAT_IDLEWAIT ||
+			    value == B43_DMA32_TXSTAT_STOPPED)
+				break;
+		}
+		msleep(1);
+	}
+	offset = dma64 ? B43_DMA64_TXCTL : B43_DMA32_TXCTL;
+	b43_write32(dev, mmio_base + offset, 0);
+	for (i = 0; i < 10; i++) {
+		offset = dma64 ? B43_DMA64_TXSTATUS : B43_DMA32_TXSTATUS;
+		value = b43_read32(dev, mmio_base + offset);
+		if (dma64) {
+			value &= B43_DMA64_TXSTAT;
+			if (value == B43_DMA64_TXSTAT_DISABLED) {
+				i = -1;
+				break;
+			}
+		} else {
+			value &= B43_DMA32_TXSTATE;
+			if (value == B43_DMA32_TXSTAT_DISABLED) {
+				i = -1;
+				break;
+			}
+		}
+		msleep(1);
+	}
+	if (i != -1) {
+		b43err(dev->wl, "DMA TX reset timed out\n");
+		return -ENODEV;
+	}
+	/* ensure the reset is completed. */
+	msleep(1);
+
+	return 0;
+}
+
+static int setup_rx_descbuffer(struct b43_dmaring *ring,
+			       struct b43_dmadesc_generic *desc,
+			       struct b43_dmadesc_meta *meta, gfp_t gfp_flags)
+{
+	struct b43_rxhdr_fw4 *rxhdr;
+	struct b43_hwtxstatus *txstat;
+	dma_addr_t dmaaddr;
+	struct sk_buff *skb;
+
+	B43_WARN_ON(ring->tx);
+
+	skb = __dev_alloc_skb(ring->rx_buffersize, gfp_flags);
+	if (unlikely(!skb))
+		return -ENOMEM;
+	dmaaddr = map_descbuffer(ring, skb->data, ring->rx_buffersize, 0);
+	if (dma_mapping_error(dmaaddr)) {
+		/* ugh. try to realloc in zone_dma */
+		gfp_flags |= GFP_DMA;
+
+		dev_kfree_skb_any(skb);
+
+		skb = __dev_alloc_skb(ring->rx_buffersize, gfp_flags);
+		if (unlikely(!skb))
+			return -ENOMEM;
+		dmaaddr = map_descbuffer(ring, skb->data,
+					 ring->rx_buffersize, 0);
+	}
+
+	if (dma_mapping_error(dmaaddr)) {
+		dev_kfree_skb_any(skb);
+		return -EIO;
+	}
+
+	meta->skb = skb;
+	meta->dmaaddr = dmaaddr;
+	ring->ops->fill_descriptor(ring, desc, dmaaddr,
+				   ring->rx_buffersize, 0, 0, 0);
+
+	rxhdr = (struct b43_rxhdr_fw4 *)(skb->data);
+	rxhdr->frame_len = 0;
+	txstat = (struct b43_hwtxstatus *)(skb->data);
+	txstat->cookie = 0;
+
+	return 0;
+}
+
+/* Allocate the initial descbuffers.
+ * This is used for an RX ring only.
+ */
+static int alloc_initial_descbuffers(struct b43_dmaring *ring)
+{
+	int i, err = -ENOMEM;
+	struct b43_dmadesc_generic *desc;
+	struct b43_dmadesc_meta *meta;
+
+	for (i = 0; i < ring->nr_slots; i++) {
+		desc = ring->ops->idx2desc(ring, i, &meta);
+
+		err = setup_rx_descbuffer(ring, desc, meta, GFP_KERNEL);
+		if (err) {
+			b43err(ring->dev->wl,
+			       "Failed to allocate initial descbuffers\n");
+			goto err_unwind;
+		}
+	}
+	mb();
+	ring->used_slots = ring->nr_slots;
+	err = 0;
+      out:
+	return err;
+
+      err_unwind:
+	for (i--; i >= 0; i--) {
+		desc = ring->ops->idx2desc(ring, i, &meta);
+
+		unmap_descbuffer(ring, meta->dmaaddr, ring->rx_buffersize, 0);
+		dev_kfree_skb(meta->skb);
+	}
+	goto out;
+}
+
+/* Do initial setup of the DMA controller.
+ * Reset the controller, write the ring busaddress
+ * and switch the "enable" bit on.
+ */
+static int dmacontroller_setup(struct b43_dmaring *ring)
+{
+	int err = 0;
+	u32 value;
+	u32 addrext;
+	u32 trans = ssb_dma_translation(ring->dev->dev);
+
+	if (ring->tx) {
+		if (ring->dma64) {
+			u64 ringbase = (u64) (ring->dmabase);
+
+			addrext = ((ringbase >> 32) & SSB_DMA_TRANSLATION_MASK)
+			    >> SSB_DMA_TRANSLATION_SHIFT;
+			value = B43_DMA64_TXENABLE;
+			value |= (addrext << B43_DMA64_TXADDREXT_SHIFT)
+			    & B43_DMA64_TXADDREXT_MASK;
+			b43_dma_write(ring, B43_DMA64_TXCTL, value);
+			b43_dma_write(ring, B43_DMA64_TXRINGLO,
+				      (ringbase & 0xFFFFFFFF));
+			b43_dma_write(ring, B43_DMA64_TXRINGHI,
+				      ((ringbase >> 32) &
+				       ~SSB_DMA_TRANSLATION_MASK)
+				      | trans);
+		} else {
+			u32 ringbase = (u32) (ring->dmabase);
+
+			addrext = (ringbase & SSB_DMA_TRANSLATION_MASK)
+			    >> SSB_DMA_TRANSLATION_SHIFT;
+			value = B43_DMA32_TXENABLE;
+			value |= (addrext << B43_DMA32_TXADDREXT_SHIFT)
+			    & B43_DMA32_TXADDREXT_MASK;
+			b43_dma_write(ring, B43_DMA32_TXCTL, value);
+			b43_dma_write(ring, B43_DMA32_TXRING,
+				      (ringbase & ~SSB_DMA_TRANSLATION_MASK)
+				      | trans);
+		}
+	} else {
+		err = alloc_initial_descbuffers(ring);
+		if (err)
+			goto out;
+		if (ring->dma64) {
+			u64 ringbase = (u64) (ring->dmabase);
+
+			addrext = ((ringbase >> 32) & SSB_DMA_TRANSLATION_MASK)
+			    >> SSB_DMA_TRANSLATION_SHIFT;
+			value = (ring->frameoffset << B43_DMA64_RXFROFF_SHIFT);
+			value |= B43_DMA64_RXENABLE;
+			value |= (addrext << B43_DMA64_RXADDREXT_SHIFT)
+			    & B43_DMA64_RXADDREXT_MASK;
+			b43_dma_write(ring, B43_DMA64_RXCTL, value);
+			b43_dma_write(ring, B43_DMA64_RXRINGLO,
+				      (ringbase & 0xFFFFFFFF));
+			b43_dma_write(ring, B43_DMA64_RXRINGHI,
+				      ((ringbase >> 32) &
+				       ~SSB_DMA_TRANSLATION_MASK)
+				      | trans);
+			b43_dma_write(ring, B43_DMA64_RXINDEX, 200);
+		} else {
+			u32 ringbase = (u32) (ring->dmabase);
+
+			addrext = (ringbase & SSB_DMA_TRANSLATION_MASK)
+			    >> SSB_DMA_TRANSLATION_SHIFT;
+			value = (ring->frameoffset << B43_DMA32_RXFROFF_SHIFT);
+			value |= B43_DMA32_RXENABLE;
+			value |= (addrext << B43_DMA32_RXADDREXT_SHIFT)
+			    & B43_DMA32_RXADDREXT_MASK;
+			b43_dma_write(ring, B43_DMA32_RXCTL, value);
+			b43_dma_write(ring, B43_DMA32_RXRING,
+				      (ringbase & ~SSB_DMA_TRANSLATION_MASK)
+				      | trans);
+			b43_dma_write(ring, B43_DMA32_RXINDEX, 200);
+		}
+	}
+
+      out:
+	return err;
+}
+
+/* Shutdown the DMA controller. */
+static void dmacontroller_cleanup(struct b43_dmaring *ring)
+{
+	if (ring->tx) {
+		b43_dmacontroller_tx_reset(ring->dev, ring->mmio_base,
+					   ring->dma64);
+		if (ring->dma64) {
+			b43_dma_write(ring, B43_DMA64_TXRINGLO, 0);
+			b43_dma_write(ring, B43_DMA64_TXRINGHI, 0);
+		} else
+			b43_dma_write(ring, B43_DMA32_TXRING, 0);
+	} else {
+		b43_dmacontroller_rx_reset(ring->dev, ring->mmio_base,
+					   ring->dma64);
+		if (ring->dma64) {
+			b43_dma_write(ring, B43_DMA64_RXRINGLO, 0);
+			b43_dma_write(ring, B43_DMA64_RXRINGHI, 0);
+		} else
+			b43_dma_write(ring, B43_DMA32_RXRING, 0);
+	}
+}
+
+static void free_all_descbuffers(struct b43_dmaring *ring)
+{
+	struct b43_dmadesc_generic *desc;
+	struct b43_dmadesc_meta *meta;
+	int i;
+
+	if (!ring->used_slots)
+		return;
+	for (i = 0; i < ring->nr_slots; i++) {
+		desc = ring->ops->idx2desc(ring, i, &meta);
+
+		if (!meta->skb) {
+			B43_WARN_ON(!ring->tx);
+			continue;
+		}
+		if (ring->tx) {
+			unmap_descbuffer(ring, meta->dmaaddr,
+					 meta->skb->len, 1);
+		} else {
+			unmap_descbuffer(ring, meta->dmaaddr,
+					 ring->rx_buffersize, 0);
+		}
+		free_descriptor_buffer(ring, meta);
+	}
+}
+
+static u64 supported_dma_mask(struct b43_wldev *dev)
+{
+	u32 tmp;
+	u16 mmio_base;
+
+	tmp = b43_read32(dev, SSB_TMSHIGH);
+	if (tmp & SSB_TMSHIGH_DMA64)
+		return DMA_64BIT_MASK;
+	mmio_base = b43_dmacontroller_base(0, 0);
+	b43_write32(dev, mmio_base + B43_DMA32_TXCTL, B43_DMA32_TXADDREXT_MASK);
+	tmp = b43_read32(dev, mmio_base + B43_DMA32_TXCTL);
+	if (tmp & B43_DMA32_TXADDREXT_MASK)
+		return DMA_32BIT_MASK;
+
+	return DMA_30BIT_MASK;
+}
+
+/* Main initialization function. */
+static
+struct b43_dmaring *b43_setup_dmaring(struct b43_wldev *dev,
+				      int controller_index,
+				      int for_tx, int dma64)
+{
+	struct b43_dmaring *ring;
+	int err;
+	int nr_slots;
+	dma_addr_t dma_test;
+
+	ring = kzalloc(sizeof(*ring), GFP_KERNEL);
+	if (!ring)
+		goto out;
+
+	nr_slots = B43_RXRING_SLOTS;
+	if (for_tx)
+		nr_slots = B43_TXRING_SLOTS;
+
+	ring->meta = kcalloc(nr_slots, sizeof(struct b43_dmadesc_meta),
+			     GFP_KERNEL);
+	if (!ring->meta)
+		goto err_kfree_ring;
+	if (for_tx) {
+		ring->txhdr_cache = kcalloc(nr_slots,
+					    sizeof(struct b43_txhdr_fw4),
+					    GFP_KERNEL);
+		if (!ring->txhdr_cache)
+			goto err_kfree_meta;
+
+		/* test for ability to dma to txhdr_cache */
+		dma_test = dma_map_single(dev->dev->dev,
+					  ring->txhdr_cache,
+					  sizeof(struct b43_txhdr_fw4),
+					  DMA_TO_DEVICE);
+
+		if (dma_mapping_error(dma_test)) {
+			/* ugh realloc */
+			kfree(ring->txhdr_cache);
+			ring->txhdr_cache = kcalloc(nr_slots,
+						    sizeof(struct
+							   b43_txhdr_fw4),
+						    GFP_KERNEL | GFP_DMA);
+			if (!ring->txhdr_cache)
+				goto err_kfree_meta;
+
+			dma_test = dma_map_single(dev->dev->dev,
+						  ring->txhdr_cache,
+						  sizeof(struct b43_txhdr_fw4),
+						  DMA_TO_DEVICE);
+
+			if (dma_mapping_error(dma_test))
+				goto err_kfree_txhdr_cache;
+		}
+
+		dma_unmap_single(dev->dev->dev,
+				 dma_test, sizeof(struct b43_txhdr_fw4),
+				 DMA_TO_DEVICE);
+	}
+
+	ring->dev = dev;
+	ring->nr_slots = nr_slots;
+	ring->mmio_base = b43_dmacontroller_base(dma64, controller_index);
+	ring->index = controller_index;
+	ring->dma64 = !!dma64;
+	if (dma64)
+		ring->ops = &dma64_ops;
+	else
+		ring->ops = &dma32_ops;
+	if (for_tx) {
+		ring->tx = 1;
+		ring->current_slot = -1;
+	} else {
+		if (ring->index == 0) {
+			ring->rx_buffersize = B43_DMA0_RX_BUFFERSIZE;
+			ring->frameoffset = B43_DMA0_RX_FRAMEOFFSET;
+		} else if (ring->index == 3) {
+			ring->rx_buffersize = B43_DMA3_RX_BUFFERSIZE;
+			ring->frameoffset = B43_DMA3_RX_FRAMEOFFSET;
+		} else
+			B43_WARN_ON(1);
+	}
+	spin_lock_init(&ring->lock);
+#ifdef CONFIG_B43_DEBUG
+	ring->last_injected_overflow = jiffies;
+#endif
+
+	err = alloc_ringmemory(ring);
+	if (err)
+		goto err_kfree_txhdr_cache;
+	err = dmacontroller_setup(ring);
+	if (err)
+		goto err_free_ringmemory;
+
+      out:
+	return ring;
+
+      err_free_ringmemory:
+	free_ringmemory(ring);
+      err_kfree_txhdr_cache:
+	kfree(ring->txhdr_cache);
+      err_kfree_meta:
+	kfree(ring->meta);
+      err_kfree_ring:
+	kfree(ring);
+	ring = NULL;
+	goto out;
+}
+
+/* Main cleanup function. */
+static void b43_destroy_dmaring(struct b43_dmaring *ring)
+{
+	if (!ring)
+		return;
+
+	b43dbg(ring->dev->wl, "DMA-%s 0x%04X (%s) max used slots: %d/%d\n",
+	       (ring->dma64) ? "64" : "32",
+	       ring->mmio_base,
+	       (ring->tx) ? "TX" : "RX", ring->max_used_slots, ring->nr_slots);
+	/* Device IRQs are disabled prior entering this function,
+	 * so no need to take care of concurrency with rx handler stuff.
+	 */
+	dmacontroller_cleanup(ring);
+	free_all_descbuffers(ring);
+	free_ringmemory(ring);
+
+	kfree(ring->txhdr_cache);
+	kfree(ring->meta);
+	kfree(ring);
+}
+
+void b43_dma_free(struct b43_wldev *dev)
+{
+	struct b43_dma *dma;
+
+	if (b43_using_pio(dev))
+		return;
+	dma = &dev->dma;
+
+	b43_destroy_dmaring(dma->rx_ring3);
+	dma->rx_ring3 = NULL;
+	b43_destroy_dmaring(dma->rx_ring0);
+	dma->rx_ring0 = NULL;
+
+	b43_destroy_dmaring(dma->tx_ring5);
+	dma->tx_ring5 = NULL;
+	b43_destroy_dmaring(dma->tx_ring4);
+	dma->tx_ring4 = NULL;
+	b43_destroy_dmaring(dma->tx_ring3);
+	dma->tx_ring3 = NULL;
+	b43_destroy_dmaring(dma->tx_ring2);
+	dma->tx_ring2 = NULL;
+	b43_destroy_dmaring(dma->tx_ring1);
+	dma->tx_ring1 = NULL;
+	b43_destroy_dmaring(dma->tx_ring0);
+	dma->tx_ring0 = NULL;
+}
+
+int b43_dma_init(struct b43_wldev *dev)
+{
+	struct b43_dma *dma = &dev->dma;
+	struct b43_dmaring *ring;
+	int err;
+	u64 dmamask;
+	int dma64 = 0;
+
+	dmamask = supported_dma_mask(dev);
+	if (dmamask == DMA_64BIT_MASK)
+		dma64 = 1;
+
+	err = ssb_dma_set_mask(dev->dev, dmamask);
+	if (err) {
+#ifdef B43_PIO
+		b43warn(dev->wl, "DMA for this device not supported. "
+			"Falling back to PIO\n");
+		dev->__using_pio = 1;
+		return -EAGAIN;
+#else
+		b43err(dev->wl, "DMA for this device not supported and "
+		       "no PIO support compiled in\n");
+		return -EOPNOTSUPP;
+#endif
+	}
+
+	err = -ENOMEM;
+	/* setup TX DMA channels. */
+	ring = b43_setup_dmaring(dev, 0, 1, dma64);
+	if (!ring)
+		goto out;
+	dma->tx_ring0 = ring;
+
+	ring = b43_setup_dmaring(dev, 1, 1, dma64);
+	if (!ring)
+		goto err_destroy_tx0;
+	dma->tx_ring1 = ring;
+
+	ring = b43_setup_dmaring(dev, 2, 1, dma64);
+	if (!ring)
+		goto err_destroy_tx1;
+	dma->tx_ring2 = ring;
+
+	ring = b43_setup_dmaring(dev, 3, 1, dma64);
+	if (!ring)
+		goto err_destroy_tx2;
+	dma->tx_ring3 = ring;
+
+	ring = b43_setup_dmaring(dev, 4, 1, dma64);
+	if (!ring)
+		goto err_destroy_tx3;
+	dma->tx_ring4 = ring;
+
+	ring = b43_setup_dmaring(dev, 5, 1, dma64);
+	if (!ring)
+		goto err_destroy_tx4;
+	dma->tx_ring5 = ring;
+
+	/* setup RX DMA channels. */
+	ring = b43_setup_dmaring(dev, 0, 0, dma64);
+	if (!ring)
+		goto err_destroy_tx5;
+	dma->rx_ring0 = ring;
+
+	if (dev->dev->id.revision < 5) {
+		ring = b43_setup_dmaring(dev, 3, 0, dma64);
+		if (!ring)
+			goto err_destroy_rx0;
+		dma->rx_ring3 = ring;
+	}
+
+	b43dbg(dev->wl, "%d-bit DMA initialized\n",
+	       (dmamask == DMA_64BIT_MASK) ? 64 :
+	       (dmamask == DMA_32BIT_MASK) ? 32 : 30);
+	err = 0;
+      out:
+	return err;
+
+      err_destroy_rx0:
+	b43_destroy_dmaring(dma->rx_ring0);
+	dma->rx_ring0 = NULL;
+      err_destroy_tx5:
+	b43_destroy_dmaring(dma->tx_ring5);
+	dma->tx_ring5 = NULL;
+      err_destroy_tx4:
+	b43_destroy_dmaring(dma->tx_ring4);
+	dma->tx_ring4 = NULL;
+      err_destroy_tx3:
+	b43_destroy_dmaring(dma->tx_ring3);
+	dma->tx_ring3 = NULL;
+      err_destroy_tx2:
+	b43_destroy_dmaring(dma->tx_ring2);
+	dma->tx_ring2 = NULL;
+      err_destroy_tx1:
+	b43_destroy_dmaring(dma->tx_ring1);
+	dma->tx_ring1 = NULL;
+      err_destroy_tx0:
+	b43_destroy_dmaring(dma->tx_ring0);
+	dma->tx_ring0 = NULL;
+	goto out;
+}
+
+/* Generate a cookie for the TX header. */
+static u16 generate_cookie(struct b43_dmaring *ring, int slot)
+{
+	u16 cookie = 0x1000;
+
+	/* Use the upper 4 bits of the cookie as
+	 * DMA controller ID and store the slot number
+	 * in the lower 12 bits.
+	 * Note that the cookie must never be 0, as this
+	 * is a special value used in RX path.
+	 */
+	switch (ring->index) {
+	case 0:
+		cookie = 0xA000;
+		break;
+	case 1:
+		cookie = 0xB000;
+		break;
+	case 2:
+		cookie = 0xC000;
+		break;
+	case 3:
+		cookie = 0xD000;
+		break;
+	case 4:
+		cookie = 0xE000;
+		break;
+	case 5:
+		cookie = 0xF000;
+		break;
+	}
+	B43_WARN_ON(slot & ~0x0FFF);
+	cookie |= (u16) slot;
+
+	return cookie;
+}
+
+/* Inspect a cookie and find out to which controller/slot it belongs. */
+static
+struct b43_dmaring *parse_cookie(struct b43_wldev *dev, u16 cookie, int *slot)
+{
+	struct b43_dma *dma = &dev->dma;
+	struct b43_dmaring *ring = NULL;
+
+	switch (cookie & 0xF000) {
+	case 0xA000:
+		ring = dma->tx_ring0;
+		break;
+	case 0xB000:
+		ring = dma->tx_ring1;
+		break;
+	case 0xC000:
+		ring = dma->tx_ring2;
+		break;
+	case 0xD000:
+		ring = dma->tx_ring3;
+		break;
+	case 0xE000:
+		ring = dma->tx_ring4;
+		break;
+	case 0xF000:
+		ring = dma->tx_ring5;
+		break;
+	default:
+		B43_WARN_ON(1);
+	}
+	*slot = (cookie & 0x0FFF);
+	B43_WARN_ON(!(ring && *slot >= 0 && *slot < ring->nr_slots));
+
+	return ring;
+}
+
+static int dma_tx_fragment(struct b43_dmaring *ring,
+			   struct sk_buff *skb,
+			   struct ieee80211_tx_control *ctl)
+{
+	const struct b43_dma_ops *ops = ring->ops;
+	u8 *header;
+	int slot;
+	int err;
+	struct b43_dmadesc_generic *desc;
+	struct b43_dmadesc_meta *meta;
+	struct b43_dmadesc_meta *meta_hdr;
+	struct sk_buff *bounce_skb;
+
+#define SLOTS_PER_PACKET  2
+	B43_WARN_ON(skb_shinfo(skb)->nr_frags);
+
+	/* Get a slot for the header. */
+	slot = request_slot(ring);
+	desc = ops->idx2desc(ring, slot, &meta_hdr);
+	memset(meta_hdr, 0, sizeof(*meta_hdr));
+
+	header = &(ring->txhdr_cache[slot * sizeof(struct b43_txhdr_fw4)]);
+	b43_generate_txhdr(ring->dev, header,
+			   skb->data, skb->len, ctl,
+			   generate_cookie(ring, slot));
+
+	meta_hdr->dmaaddr = map_descbuffer(ring, (unsigned char *)header,
+					   sizeof(struct b43_txhdr_fw4), 1);
+	if (dma_mapping_error(meta_hdr->dmaaddr))
+		return -EIO;
+	ops->fill_descriptor(ring, desc, meta_hdr->dmaaddr,
+			     sizeof(struct b43_txhdr_fw4), 1, 0, 0);
+
+	/* Get a slot for the payload. */
+	slot = request_slot(ring);
+	desc = ops->idx2desc(ring, slot, &meta);
+	memset(meta, 0, sizeof(*meta));
+
+	memcpy(&meta->txstat.control, ctl, sizeof(*ctl));
+	meta->skb = skb;
+	meta->is_last_fragment = 1;
+
+	meta->dmaaddr = map_descbuffer(ring, skb->data, skb->len, 1);
+	/* create a bounce buffer in zone_dma on mapping failure. */
+	if (dma_mapping_error(meta->dmaaddr)) {
+		bounce_skb = __dev_alloc_skb(skb->len, GFP_ATOMIC | GFP_DMA);
+		if (!bounce_skb) {
+			err = -ENOMEM;
+			goto out_unmap_hdr;
+		}
+
+		memcpy(skb_put(bounce_skb, skb->len), skb->data, skb->len);
+		dev_kfree_skb_any(skb);
+		skb = bounce_skb;
+		meta->skb = skb;
+		meta->dmaaddr = map_descbuffer(ring, skb->data, skb->len, 1);
+		if (dma_mapping_error(meta->dmaaddr)) {
+			err = -EIO;
+			goto out_free_bounce;
+		}
+	}
+
+	ops->fill_descriptor(ring, desc, meta->dmaaddr, skb->len, 0, 1, 1);
+
+	/* Now transfer the whole frame. */
+	wmb();
+	ops->poke_tx(ring, next_slot(ring, slot));
+	return 0;
+
+      out_free_bounce:
+	dev_kfree_skb_any(skb);
+      out_unmap_hdr:
+	unmap_descbuffer(ring, meta_hdr->dmaaddr,
+			 sizeof(struct b43_txhdr_fw4), 1);
+	return err;
+}
+
+static inline int should_inject_overflow(struct b43_dmaring *ring)
+{
+#ifdef CONFIG_B43_DEBUG
+	if (unlikely(b43_debug(ring->dev, B43_DBG_DMAOVERFLOW))) {
+		/* Check if we should inject another ringbuffer overflow
+		 * to test handling of this situation in the stack. */
+		unsigned long next_overflow;
+
+		next_overflow = ring->last_injected_overflow + HZ;
+		if (time_after(jiffies, next_overflow)) {
+			ring->last_injected_overflow = jiffies;
+			b43dbg(ring->dev->wl,
+			       "Injecting TX ring overflow on "
+			       "DMA controller %d\n", ring->index);
+			return 1;
+		}
+	}
+#endif /* CONFIG_B43_DEBUG */
+	return 0;
+}
+
+int b43_dma_tx(struct b43_wldev *dev,
+	       struct sk_buff *skb, struct ieee80211_tx_control *ctl)
+{
+	struct b43_dmaring *ring;
+	int err = 0;
+	unsigned long flags;
+
+	ring = priority_to_txring(dev, ctl->queue);
+	spin_lock_irqsave(&ring->lock, flags);
+	B43_WARN_ON(!ring->tx);
+	if (unlikely(free_slots(ring) < SLOTS_PER_PACKET)) {
+		b43warn(dev->wl, "DMA queue overflow\n");
+		err = -ENOSPC;
+		goto out_unlock;
+	}
+	/* Check if the queue was stopped in mac80211,
+	 * but we got called nevertheless.
+	 * That would be a mac80211 bug. */
+	B43_WARN_ON(ring->stopped);
+
+	err = dma_tx_fragment(ring, skb, ctl);
+	if (unlikely(err)) {
+		b43err(dev->wl, "DMA tx mapping failure\n");
+		goto out_unlock;
+	}
+	ring->nr_tx_packets++;
+	if ((free_slots(ring) < SLOTS_PER_PACKET) ||
+	    should_inject_overflow(ring)) {
+		/* This TX ring is full. */
+		ieee80211_stop_queue(dev->wl->hw, txring_to_priority(ring));
+		ring->stopped = 1;
+		if (b43_debug(dev, B43_DBG_DMAVERBOSE)) {
+			b43dbg(dev->wl, "Stopped TX ring %d\n", ring->index);
+		}
+	}
+      out_unlock:
+	spin_unlock_irqrestore(&ring->lock, flags);
+
+	return err;
+}
+
+void b43_dma_handle_txstatus(struct b43_wldev *dev,
+			     const struct b43_txstatus *status)
+{
+	const struct b43_dma_ops *ops;
+	struct b43_dmaring *ring;
+	struct b43_dmadesc_generic *desc;
+	struct b43_dmadesc_meta *meta;
+	int slot;
+
+	ring = parse_cookie(dev, status->cookie, &slot);
+	if (unlikely(!ring))
+		return;
+	B43_WARN_ON(!irqs_disabled());
+	spin_lock(&ring->lock);
+
+	B43_WARN_ON(!ring->tx);
+	ops = ring->ops;
+	while (1) {
+		B43_WARN_ON(!(slot >= 0 && slot < ring->nr_slots));
+		desc = ops->idx2desc(ring, slot, &meta);
+
+		if (meta->skb)
+			unmap_descbuffer(ring, meta->dmaaddr, meta->skb->len,
+					 1);
+		else
+			unmap_descbuffer(ring, meta->dmaaddr,
+					 sizeof(struct b43_txhdr_fw4), 1);
+
+		if (meta->is_last_fragment) {
+			B43_WARN_ON(!meta->skb);
+			/* Call back to inform the ieee80211 subsystem about the
+			 * status of the transmission.
+			 * Some fields of txstat are already filled in dma_tx().
+			 */
+			if (status->acked) {
+				meta->txstat.flags |= IEEE80211_TX_STATUS_ACK;
+			} else {
+				if (!(meta->txstat.control.flags
+				      & IEEE80211_TXCTL_NO_ACK))
+					meta->txstat.excessive_retries = 1;
+			}
+			if (status->frame_count == 0) {
+				/* The frame was not transmitted at all. */
+				meta->txstat.retry_count = 0;
+			} else
+				meta->txstat.retry_count = status->frame_count - 1;
+			ieee80211_tx_status_irqsafe(dev->wl->hw, meta->skb,
+						    &(meta->txstat));
+			/* skb is freed by ieee80211_tx_status_irqsafe() */
+			meta->skb = NULL;
+		} else {
+			/* No need to call free_descriptor_buffer here, as
+			 * this is only the txhdr, which is not allocated.
+			 */
+			B43_WARN_ON(meta->skb);
+		}
+
+		/* Everything unmapped and free'd. So it's not used anymore. */
+		ring->used_slots--;
+
+		if (meta->is_last_fragment)
+			break;
+		slot = next_slot(ring, slot);
+	}
+	dev->stats.last_tx = jiffies;
+	if (ring->stopped) {
+		B43_WARN_ON(free_slots(ring) < SLOTS_PER_PACKET);
+		ieee80211_wake_queue(dev->wl->hw, txring_to_priority(ring));
+		ring->stopped = 0;
+		if (b43_debug(dev, B43_DBG_DMAVERBOSE)) {
+			b43dbg(dev->wl, "Woke up TX ring %d\n", ring->index);
+		}
+	}
+
+	spin_unlock(&ring->lock);
+}
+
+void b43_dma_get_tx_stats(struct b43_wldev *dev,
+			  struct ieee80211_tx_queue_stats *stats)
+{
+	const int nr_queues = dev->wl->hw->queues;
+	struct b43_dmaring *ring;
+	struct ieee80211_tx_queue_stats_data *data;
+	unsigned long flags;
+	int i;
+
+	for (i = 0; i < nr_queues; i++) {
+		data = &(stats->data[i]);
+		ring = priority_to_txring(dev, i);
+
+		spin_lock_irqsave(&ring->lock, flags);
+		data->len = ring->used_slots / SLOTS_PER_PACKET;
+		data->limit = ring->nr_slots / SLOTS_PER_PACKET;
+		data->count = ring->nr_tx_packets;
+		spin_unlock_irqrestore(&ring->lock, flags);
+	}
+}
+
+static void dma_rx(struct b43_dmaring *ring, int *slot)
+{
+	const struct b43_dma_ops *ops = ring->ops;
+	struct b43_dmadesc_generic *desc;
+	struct b43_dmadesc_meta *meta;
+	struct b43_rxhdr_fw4 *rxhdr;
+	struct sk_buff *skb;
+	u16 len;
+	int err;
+	dma_addr_t dmaaddr;
+
+	desc = ops->idx2desc(ring, *slot, &meta);
+
+	sync_descbuffer_for_cpu(ring, meta->dmaaddr, ring->rx_buffersize);
+	skb = meta->skb;
+
+	if (ring->index == 3) {
+		/* We received an xmit status. */
+		struct b43_hwtxstatus *hw = (struct b43_hwtxstatus *)skb->data;
+		int i = 0;
+
+		while (hw->cookie == 0) {
+			if (i > 100)
+				break;
+			i++;
+			udelay(2);
+			barrier();
+		}
+		b43_handle_hwtxstatus(ring->dev, hw);
+		/* recycle the descriptor buffer. */
+		sync_descbuffer_for_device(ring, meta->dmaaddr,
+					   ring->rx_buffersize);
+
+		return;
+	}
+	rxhdr = (struct b43_rxhdr_fw4 *)skb->data;
+	len = le16_to_cpu(rxhdr->frame_len);
+	if (len == 0) {
+		int i = 0;
+
+		do {
+			udelay(2);
+			barrier();
+			len = le16_to_cpu(rxhdr->frame_len);
+		} while (len == 0 && i++ < 5);
+		if (unlikely(len == 0)) {
+			/* recycle the descriptor buffer. */
+			sync_descbuffer_for_device(ring, meta->dmaaddr,
+						   ring->rx_buffersize);
+			goto drop;
+		}
+	}
+	if (unlikely(len > ring->rx_buffersize)) {
+		/* The data did not fit into one descriptor buffer
+		 * and is split over multiple buffers.
+		 * This should never happen, as we try to allocate buffers
+		 * big enough. So simply ignore this packet.
+		 */
+		int cnt = 0;
+		s32 tmp = len;
+
+		while (1) {
+			desc = ops->idx2desc(ring, *slot, &meta);
+			/* recycle the descriptor buffer. */
+			sync_descbuffer_for_device(ring, meta->dmaaddr,
+						   ring->rx_buffersize);
+			*slot = next_slot(ring, *slot);
+			cnt++;
+			tmp -= ring->rx_buffersize;
+			if (tmp <= 0)
+				break;
+		}
+		b43err(ring->dev->wl, "DMA RX buffer too small "
+		       "(len: %u, buffer: %u, nr-dropped: %d)\n",
+		       len, ring->rx_buffersize, cnt);
+		goto drop;
+	}
+
+	dmaaddr = meta->dmaaddr;
+	err = setup_rx_descbuffer(ring, desc, meta, GFP_ATOMIC);
+	if (unlikely(err)) {
+		b43dbg(ring->dev->wl, "DMA RX: setup_rx_descbuffer() failed\n");
+		sync_descbuffer_for_device(ring, dmaaddr, ring->rx_buffersize);
+		goto drop;
+	}
+
+	unmap_descbuffer(ring, dmaaddr, ring->rx_buffersize, 0);
+	skb_put(skb, len + ring->frameoffset);
+	skb_pull(skb, ring->frameoffset);
+
+	b43_rx(ring->dev, skb, rxhdr);
+      drop:
+	return;
+}
+
+void b43_dma_rx(struct b43_dmaring *ring)
+{
+	const struct b43_dma_ops *ops = ring->ops;
+	int slot, current_slot;
+	int used_slots = 0;
+
+	B43_WARN_ON(ring->tx);
+	current_slot = ops->get_current_rxslot(ring);
+	B43_WARN_ON(!(current_slot >= 0 && current_slot < ring->nr_slots));
+
+	slot = ring->current_slot;
+	for (; slot != current_slot; slot = next_slot(ring, slot)) {
+		dma_rx(ring, &slot);
+		update_max_used_slots(ring, ++used_slots);
+	}
+	ops->set_current_rxslot(ring, slot);
+	ring->current_slot = slot;
+}
+
+static void b43_dma_tx_suspend_ring(struct b43_dmaring *ring)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&ring->lock, flags);
+	B43_WARN_ON(!ring->tx);
+	ring->ops->tx_suspend(ring);
+	spin_unlock_irqrestore(&ring->lock, flags);
+}
+
+static void b43_dma_tx_resume_ring(struct b43_dmaring *ring)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&ring->lock, flags);
+	B43_WARN_ON(!ring->tx);
+	ring->ops->tx_resume(ring);
+	spin_unlock_irqrestore(&ring->lock, flags);
+}
+
+void b43_dma_tx_suspend(struct b43_wldev *dev)
+{
+	b43_power_saving_ctl_bits(dev, B43_PS_AWAKE);
+	b43_dma_tx_suspend_ring(dev->dma.tx_ring0);
+	b43_dma_tx_suspend_ring(dev->dma.tx_ring1);
+	b43_dma_tx_suspend_ring(dev->dma.tx_ring2);
+	b43_dma_tx_suspend_ring(dev->dma.tx_ring3);
+	b43_dma_tx_suspend_ring(dev->dma.tx_ring4);
+	b43_dma_tx_suspend_ring(dev->dma.tx_ring5);
+}
+
+void b43_dma_tx_resume(struct b43_wldev *dev)
+{
+	b43_dma_tx_resume_ring(dev->dma.tx_ring5);
+	b43_dma_tx_resume_ring(dev->dma.tx_ring4);
+	b43_dma_tx_resume_ring(dev->dma.tx_ring3);
+	b43_dma_tx_resume_ring(dev->dma.tx_ring2);
+	b43_dma_tx_resume_ring(dev->dma.tx_ring1);
+	b43_dma_tx_resume_ring(dev->dma.tx_ring0);
+	b43_power_saving_ctl_bits(dev, 0);
+}