pio.c

linux 内核源代码

	INIT_LIST_HEAD(&queue->txfree);
	INIT_LIST_HEAD(&queue->txqueue);
	INIT_LIST_HEAD(&queue->txrunning);
	tasklet_init(&queue->txtask, tx_tasklet,
		     (unsigned long)queue);

	value = b43legacy_read32(dev, B43legacy_MMIO_STATUS_BITFIELD);
	value &= ~B43legacy_SBF_XFER_REG_BYTESWAP;
	b43legacy_write32(dev, B43legacy_MMIO_STATUS_BITFIELD, value);

	qsize = b43legacy_read16(dev, queue->mmio_base
				 + B43legacy_PIO_TXQBUFSIZE);
	if (qsize == 0) {
		b43legacyerr(dev->wl, "This card does not support PIO "
		       "operation mode. Please use DMA mode "
		       "(module parameter pio=0).\n");
		goto err_freequeue;
	}
	if (qsize <= B43legacy_PIO_TXQADJUST) {
		b43legacyerr(dev->wl, "PIO tx device-queue too small (%u)\n",
		       qsize);
		goto err_freequeue;
	}
	qsize -= B43legacy_PIO_TXQADJUST;
	queue->tx_devq_size = qsize;

	setup_txqueues(queue);

out:
	return queue;

err_freequeue:
	kfree(queue);
	queue = NULL;
	goto out;
}

static void cancel_transfers(struct b43legacy_pioqueue *queue)
{
	struct b43legacy_pio_txpacket *packet, *tmp_packet;

	tasklet_disable(&queue->txtask);

	list_for_each_entry_safe(packet, tmp_packet, &queue->txrunning, list)
		free_txpacket(packet, 0);
	list_for_each_entry_safe(packet, tmp_packet, &queue->txqueue, list)
		free_txpacket(packet, 0);
}

static void b43legacy_destroy_pioqueue(struct b43legacy_pioqueue *queue)
{
	if (!queue)
		return;

	cancel_transfers(queue);
	kfree(queue);
}

void b43legacy_pio_free(struct b43legacy_wldev *dev)
{
	struct b43legacy_pio *pio;

	if (!b43legacy_using_pio(dev))
		return;
	pio = &dev->pio;

	b43legacy_destroy_pioqueue(pio->queue3);
	pio->queue3 = NULL;
	b43legacy_destroy_pioqueue(pio->queue2);
	pio->queue2 = NULL;
	b43legacy_destroy_pioqueue(pio->queue1);
	pio->queue1 = NULL;
	b43legacy_destroy_pioqueue(pio->queue0);
	pio->queue0 = NULL;
}

int b43legacy_pio_init(struct b43legacy_wldev *dev)
{
	struct b43legacy_pio *pio = &dev->pio;
	struct b43legacy_pioqueue *queue;
	int err = -ENOMEM;

	queue = b43legacy_setup_pioqueue(dev, B43legacy_MMIO_PIO1_BASE);
	if (!queue)
		goto out;
	pio->queue0 = queue;

	queue = b43legacy_setup_pioqueue(dev, B43legacy_MMIO_PIO2_BASE);
	if (!queue)
		goto err_destroy0;
	pio->queue1 = queue;

	queue = b43legacy_setup_pioqueue(dev, B43legacy_MMIO_PIO3_BASE);
	if (!queue)
		goto err_destroy1;
	pio->queue2 = queue;

	queue = b43legacy_setup_pioqueue(dev, B43legacy_MMIO_PIO4_BASE);
	if (!queue)
		goto err_destroy2;
	pio->queue3 = queue;

	if (dev->dev->id.revision < 3)
		dev->irq_savedstate |= B43legacy_IRQ_PIO_WORKAROUND;

	b43legacydbg(dev->wl, "PIO initialized\n");
	err = 0;
out:
	return err;

err_destroy2:
	b43legacy_destroy_pioqueue(pio->queue2);
	pio->queue2 = NULL;
err_destroy1:
	b43legacy_destroy_pioqueue(pio->queue1);
	pio->queue1 = NULL;
err_destroy0:
	b43legacy_destroy_pioqueue(pio->queue0);
	pio->queue0 = NULL;
	goto out;
}

int b43legacy_pio_tx(struct b43legacy_wldev *dev,
		     struct sk_buff *skb,
		     struct ieee80211_tx_control *ctl)
{
	struct b43legacy_pioqueue *queue = dev->pio.queue1;
	struct b43legacy_pio_txpacket *packet;

	B43legacy_WARN_ON(queue->tx_suspended);
	B43legacy_WARN_ON(list_empty(&queue->txfree));

	packet = list_entry(queue->txfree.next, struct b43legacy_pio_txpacket,
			    list);
	packet->skb = skb;

	memset(&packet->txstat, 0, sizeof(packet->txstat));
	memcpy(&packet->txstat.control, ctl, sizeof(*ctl));

	list_move_tail(&packet->list, &queue->txqueue);
	queue->nr_txfree--;
	queue->nr_tx_packets++;
	B43legacy_WARN_ON(queue->nr_txfree >= B43legacy_PIO_MAXTXPACKETS);

	tasklet_schedule(&queue->txtask);

	return 0;
}

void b43legacy_pio_handle_txstatus(struct b43legacy_wldev *dev,
				   const struct b43legacy_txstatus *status)
{
	struct b43legacy_pioqueue *queue;
	struct b43legacy_pio_txpacket *packet;

	queue = parse_cookie(dev, status->cookie, &packet);
	B43legacy_WARN_ON(!queue);

	if (!packet->skb)
		return;

	queue->tx_devq_packets--;
	queue->tx_devq_used -= (packet->skb->len +
				sizeof(struct b43legacy_txhdr_fw3));

	if (status->acked)
		packet->txstat.flags |= IEEE80211_TX_STATUS_ACK;
	packet->txstat.retry_count = status->frame_count - 1;
	ieee80211_tx_status_irqsafe(dev->wl->hw, packet->skb,
				    &(packet->txstat));
	packet->skb = NULL;

	free_txpacket(packet, 1);
	/* If there are packets on the txqueue, poke the tasklet
	 * to transmit them.
	 */
	if (!list_empty(&queue->txqueue))
		tasklet_schedule(&queue->txtask);
}

void b43legacy_pio_get_tx_stats(struct b43legacy_wldev *dev,
				struct ieee80211_tx_queue_stats *stats)
{
	struct b43legacy_pio *pio = &dev->pio;
	struct b43legacy_pioqueue *queue;
	struct ieee80211_tx_queue_stats_data *data;

	queue = pio->queue1;
	data = &(stats->data[0]);
	data->len = B43legacy_PIO_MAXTXPACKETS - queue->nr_txfree;
	data->limit = B43legacy_PIO_MAXTXPACKETS;
	data->count = queue->nr_tx_packets;
}

static void pio_rx_error(struct b43legacy_pioqueue *queue,
			 int clear_buffers,
			 const char *error)
{
	int i;

	b43legacyerr(queue->dev->wl, "PIO RX error: %s\n", error);
	b43legacy_pio_write(queue, B43legacy_PIO_RXCTL,
			    B43legacy_PIO_RXCTL_READY);
	if (clear_buffers) {
		B43legacy_WARN_ON(queue->mmio_base != B43legacy_MMIO_PIO1_BASE);
		for (i = 0; i < 15; i++) {
			/* Dummy read. */
			b43legacy_pio_read(queue, B43legacy_PIO_RXDATA);
		}
	}
}

void b43legacy_pio_rx(struct b43legacy_pioqueue *queue)
{
	__le16 preamble[21] = { 0 };
	struct b43legacy_rxhdr_fw3 *rxhdr;
	u16 tmp;
	u16 len;
	u16 macstat;
	int i;
	int preamble_readwords;
	struct sk_buff *skb;

	tmp = b43legacy_pio_read(queue, B43legacy_PIO_RXCTL);
	if (!(tmp & B43legacy_PIO_RXCTL_DATAAVAILABLE))
		return;
	b43legacy_pio_write(queue, B43legacy_PIO_RXCTL,
			    B43legacy_PIO_RXCTL_DATAAVAILABLE);

	for (i = 0; i < 10; i++) {
		tmp = b43legacy_pio_read(queue, B43legacy_PIO_RXCTL);
		if (tmp & B43legacy_PIO_RXCTL_READY)
			goto data_ready;
		udelay(10);
	}
	b43legacydbg(queue->dev->wl, "PIO RX timed out\n");
	return;
data_ready:

	len = b43legacy_pio_read(queue, B43legacy_PIO_RXDATA);
	if (unlikely(len > 0x700)) {
		pio_rx_error(queue, 0, "len > 0x700");
		return;
	}
	if (unlikely(len == 0 && queue->mmio_base !=
		     B43legacy_MMIO_PIO4_BASE)) {
		pio_rx_error(queue, 0, "len == 0");
		return;
	}
	preamble[0] = cpu_to_le16(len);
	if (queue->mmio_base == B43legacy_MMIO_PIO4_BASE)
		preamble_readwords = 14 / sizeof(u16);
	else
		preamble_readwords = 18 / sizeof(u16);
	for (i = 0; i < preamble_readwords; i++) {
		tmp = b43legacy_pio_read(queue, B43legacy_PIO_RXDATA);
		preamble[i + 1] = cpu_to_le16(tmp);
	}
	rxhdr = (struct b43legacy_rxhdr_fw3 *)preamble;
	macstat = le16_to_cpu(rxhdr->mac_status);
	if (macstat & B43legacy_RX_MAC_FCSERR) {
		pio_rx_error(queue,
			     (queue->mmio_base == B43legacy_MMIO_PIO1_BASE),
			     "Frame FCS error");
		return;
	}
	if (queue->mmio_base == B43legacy_MMIO_PIO4_BASE) {
		/* We received an xmit status. */
		struct b43legacy_hwtxstatus *hw;

		hw = (struct b43legacy_hwtxstatus *)(preamble + 1);
		b43legacy_handle_hwtxstatus(queue->dev, hw);

		return;
	}

	skb = dev_alloc_skb(len);
	if (unlikely(!skb)) {
		pio_rx_error(queue, 1, "OOM");
		return;
	}
	skb_put(skb, len);
	for (i = 0; i < len - 1; i += 2) {
		tmp = b43legacy_pio_read(queue, B43legacy_PIO_RXDATA);
		*((__le16 *)(skb->data + i)) = cpu_to_le16(tmp);
	}
	if (len % 2) {
		tmp = b43legacy_pio_read(queue, B43legacy_PIO_RXDATA);
		skb->data[len - 1] = (tmp & 0x00FF);
	}
	b43legacy_rx(queue->dev, skb, rxhdr);
}

void b43legacy_pio_tx_suspend(struct b43legacy_pioqueue *queue)
{
	b43legacy_power_saving_ctl_bits(queue->dev, -1, 1);
	b43legacy_pio_write(queue, B43legacy_PIO_TXCTL,
			    b43legacy_pio_read(queue, B43legacy_PIO_TXCTL)
			    | B43legacy_PIO_TXCTL_SUSPEND);
}

void b43legacy_pio_tx_resume(struct b43legacy_pioqueue *queue)
{
	b43legacy_pio_write(queue, B43legacy_PIO_TXCTL,
			    b43legacy_pio_read(queue, B43legacy_PIO_TXCTL)
			    & ~B43legacy_PIO_TXCTL_SUSPEND);
	b43legacy_power_saving_ctl_bits(queue->dev, -1, -1);
	tasklet_schedule(&queue->txtask);
}

void b43legacy_pio_freeze_txqueues(struct b43legacy_wldev *dev)
{
	struct b43legacy_pio *pio;

	B43legacy_WARN_ON(!b43legacy_using_pio(dev));
	pio = &dev->pio;
	pio->queue0->tx_frozen = 1;
	pio->queue1->tx_frozen = 1;
	pio->queue2->tx_frozen = 1;
	pio->queue3->tx_frozen = 1;
}

void b43legacy_pio_thaw_txqueues(struct b43legacy_wldev *dev)
{
	struct b43legacy_pio *pio;

	B43legacy_WARN_ON(!b43legacy_using_pio(dev));
	pio = &dev->pio;
	pio->queue0->tx_frozen = 0;
	pio->queue1->tx_frozen = 0;
	pio->queue2->tx_frozen = 0;
	pio->queue3->tx_frozen = 0;
	if (!list_empty(&pio->queue0->txqueue))
		tasklet_schedule(&pio->queue0->txtask);
	if (!list_empty(&pio->queue1->txqueue))
		tasklet_schedule(&pio->queue1->txtask);
	if (!list_empty(&pio->queue2->txqueue))
		tasklet_schedule(&pio->queue2->txtask);
	if (!list_empty(&pio->queue3->txqueue))
		tasklet_schedule(&pio->queue3->txtask);
}