Initial import

1 files changed, 526 insertions, 0 deletions

diff --git a/drivers/isdn/mISDN/hwchannel.c b/drivers/isdn/mISDN/hwchannel.c
new file mode 100644
index 000000000..84b4b0f7e
--- /dev/null
+++ b/drivers/isdn/mISDN/hwchannel.c
@@ -0,0 +1,526 @@
+/*
+ *
+ * Author	Karsten Keil <kkeil@novell.com>
+ *
+ * Copyright 2008  by Karsten Keil <kkeil@novell.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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.
+ *
+ */
+
+#include <linux/gfp.h>
+#include <linux/module.h>
+#include <linux/mISDNhw.h>
+
+static void
+dchannel_bh(struct work_struct *ws)
+{
+	struct dchannel	*dch  = container_of(ws, struct dchannel, workq);
+	struct sk_buff	*skb;
+	int		err;
+
+	if (test_and_clear_bit(FLG_RECVQUEUE, &dch->Flags)) {
+		while ((skb = skb_dequeue(&dch->rqueue))) {
+			if (likely(dch->dev.D.peer)) {
+				err = dch->dev.D.recv(dch->dev.D.peer, skb);
+				if (err)
+					dev_kfree_skb(skb);
+			} else
+				dev_kfree_skb(skb);
+		}
+	}
+	if (test_and_clear_bit(FLG_PHCHANGE, &dch->Flags)) {
+		if (dch->phfunc)
+			dch->phfunc(dch);
+	}
+}
+
+static void
+bchannel_bh(struct work_struct *ws)
+{
+	struct bchannel	*bch  = container_of(ws, struct bchannel, workq);
+	struct sk_buff	*skb;
+	int		err;
+
+	if (test_and_clear_bit(FLG_RECVQUEUE, &bch->Flags)) {
+		while ((skb = skb_dequeue(&bch->rqueue))) {
+			bch->rcount--;
+			if (likely(bch->ch.peer)) {
+				err = bch->ch.recv(bch->ch.peer, skb);
+				if (err)
+					dev_kfree_skb(skb);
+			} else
+				dev_kfree_skb(skb);
+		}
+	}
+}
+
+int
+mISDN_initdchannel(struct dchannel *ch, int maxlen, void *phf)
+{
+	test_and_set_bit(FLG_HDLC, &ch->Flags);
+	ch->maxlen = maxlen;
+	ch->hw = NULL;
+	ch->rx_skb = NULL;
+	ch->tx_skb = NULL;
+	ch->tx_idx = 0;
+	ch->phfunc = phf;
+	skb_queue_head_init(&ch->squeue);
+	skb_queue_head_init(&ch->rqueue);
+	INIT_LIST_HEAD(&ch->dev.bchannels);
+	INIT_WORK(&ch->workq, dchannel_bh);
+	return 0;
+}
+EXPORT_SYMBOL(mISDN_initdchannel);
+
+int
+mISDN_initbchannel(struct bchannel *ch, unsigned short maxlen,
+		   unsigned short minlen)
+{
+	ch->Flags = 0;
+	ch->minlen = minlen;
+	ch->next_minlen = minlen;
+	ch->init_minlen = minlen;
+	ch->maxlen = maxlen;
+	ch->next_maxlen = maxlen;
+	ch->init_maxlen = maxlen;
+	ch->hw = NULL;
+	ch->rx_skb = NULL;
+	ch->tx_skb = NULL;
+	ch->tx_idx = 0;
+	skb_queue_head_init(&ch->rqueue);
+	ch->rcount = 0;
+	ch->next_skb = NULL;
+	INIT_WORK(&ch->workq, bchannel_bh);
+	return 0;
+}
+EXPORT_SYMBOL(mISDN_initbchannel);
+
+int
+mISDN_freedchannel(struct dchannel *ch)
+{
+	if (ch->tx_skb) {
+		dev_kfree_skb(ch->tx_skb);
+		ch->tx_skb = NULL;
+	}
+	if (ch->rx_skb) {
+		dev_kfree_skb(ch->rx_skb);
+		ch->rx_skb = NULL;
+	}
+	skb_queue_purge(&ch->squeue);
+	skb_queue_purge(&ch->rqueue);
+	flush_work(&ch->workq);
+	return 0;
+}
+EXPORT_SYMBOL(mISDN_freedchannel);
+
+void
+mISDN_clear_bchannel(struct bchannel *ch)
+{
+	if (ch->tx_skb) {
+		dev_kfree_skb(ch->tx_skb);
+		ch->tx_skb = NULL;
+	}
+	ch->tx_idx = 0;
+	if (ch->rx_skb) {
+		dev_kfree_skb(ch->rx_skb);
+		ch->rx_skb = NULL;
+	}
+	if (ch->next_skb) {
+		dev_kfree_skb(ch->next_skb);
+		ch->next_skb = NULL;
+	}
+	test_and_clear_bit(FLG_TX_BUSY, &ch->Flags);
+	test_and_clear_bit(FLG_TX_NEXT, &ch->Flags);
+	test_and_clear_bit(FLG_ACTIVE, &ch->Flags);
+	test_and_clear_bit(FLG_FILLEMPTY, &ch->Flags);
+	test_and_clear_bit(FLG_TX_EMPTY, &ch->Flags);
+	test_and_clear_bit(FLG_RX_OFF, &ch->Flags);
+	ch->dropcnt = 0;
+	ch->minlen = ch->init_minlen;
+	ch->next_minlen = ch->init_minlen;
+	ch->maxlen = ch->init_maxlen;
+	ch->next_maxlen = ch->init_maxlen;
+	skb_queue_purge(&ch->rqueue);
+	ch->rcount = 0;
+}
+EXPORT_SYMBOL(mISDN_clear_bchannel);
+
+void
+mISDN_freebchannel(struct bchannel *ch)
+{
+	cancel_work_sync(&ch->workq);
+	mISDN_clear_bchannel(ch);
+}
+EXPORT_SYMBOL(mISDN_freebchannel);
+
+int
+mISDN_ctrl_bchannel(struct bchannel *bch, struct mISDN_ctrl_req *cq)
+{
+	int ret = 0;
+
+	switch (cq->op) {
+	case MISDN_CTRL_GETOP:
+		cq->op = MISDN_CTRL_RX_BUFFER | MISDN_CTRL_FILL_EMPTY |
+			 MISDN_CTRL_RX_OFF;
+		break;
+	case MISDN_CTRL_FILL_EMPTY:
+		if (cq->p1) {
+			memset(bch->fill, cq->p2 & 0xff, MISDN_BCH_FILL_SIZE);
+			test_and_set_bit(FLG_FILLEMPTY, &bch->Flags);
+		} else {
+			test_and_clear_bit(FLG_FILLEMPTY, &bch->Flags);
+		}
+		break;
+	case MISDN_CTRL_RX_OFF:
+		/* read back dropped byte count */
+		cq->p2 = bch->dropcnt;
+		if (cq->p1)
+			test_and_set_bit(FLG_RX_OFF, &bch->Flags);
+		else
+			test_and_clear_bit(FLG_RX_OFF, &bch->Flags);
+		bch->dropcnt = 0;
+		break;
+	case MISDN_CTRL_RX_BUFFER:
+		if (cq->p2 > MISDN_CTRL_RX_SIZE_IGNORE)
+			bch->next_maxlen = cq->p2;
+		if (cq->p1 > MISDN_CTRL_RX_SIZE_IGNORE)
+			bch->next_minlen = cq->p1;
+		/* we return the old values */
+		cq->p1 = bch->minlen;
+		cq->p2 = bch->maxlen;
+		break;
+	default:
+		pr_info("mISDN unhandled control %x operation\n", cq->op);
+		ret = -EINVAL;
+		break;
+	}
+	return ret;
+}
+EXPORT_SYMBOL(mISDN_ctrl_bchannel);
+
+static inline u_int
+get_sapi_tei(u_char *p)
+{
+	u_int	sapi, tei;
+
+	sapi = *p >> 2;
+	tei = p[1] >> 1;
+	return sapi | (tei << 8);
+}
+
+void
+recv_Dchannel(struct dchannel *dch)
+{
+	struct mISDNhead *hh;
+
+	if (dch->rx_skb->len < 2) { /* at least 2 for sapi / tei */
+		dev_kfree_skb(dch->rx_skb);
+		dch->rx_skb = NULL;
+		return;
+	}
+	hh = mISDN_HEAD_P(dch->rx_skb);
+	hh->prim = PH_DATA_IND;
+	hh->id = get_sapi_tei(dch->rx_skb->data);
+	skb_queue_tail(&dch->rqueue, dch->rx_skb);
+	dch->rx_skb = NULL;
+	schedule_event(dch, FLG_RECVQUEUE);
+}
+EXPORT_SYMBOL(recv_Dchannel);
+
+void
+recv_Echannel(struct dchannel *ech, struct dchannel *dch)
+{
+	struct mISDNhead *hh;
+
+	if (ech->rx_skb->len < 2) { /* at least 2 for sapi / tei */
+		dev_kfree_skb(ech->rx_skb);
+		ech->rx_skb = NULL;
+		return;
+	}
+	hh = mISDN_HEAD_P(ech->rx_skb);
+	hh->prim = PH_DATA_E_IND;
+	hh->id = get_sapi_tei(ech->rx_skb->data);
+	skb_queue_tail(&dch->rqueue, ech->rx_skb);
+	ech->rx_skb = NULL;
+	schedule_event(dch, FLG_RECVQUEUE);
+}
+EXPORT_SYMBOL(recv_Echannel);
+
+void
+recv_Bchannel(struct bchannel *bch, unsigned int id, bool force)
+{
+	struct mISDNhead *hh;
+
+	/* if allocation did fail upper functions still may call us */
+	if (unlikely(!bch->rx_skb))
+		return;
+	if (unlikely(!bch->rx_skb->len)) {
+		/* we have no data to send - this may happen after recovery
+		 * from overflow or too small allocation.
+		 * We need to free the buffer here */
+		dev_kfree_skb(bch->rx_skb);
+		bch->rx_skb = NULL;
+	} else {
+		if (test_bit(FLG_TRANSPARENT, &bch->Flags) &&
+		    (bch->rx_skb->len < bch->minlen) && !force)
+				return;
+		hh = mISDN_HEAD_P(bch->rx_skb);
+		hh->prim = PH_DATA_IND;
+		hh->id = id;
+		if (bch->rcount >= 64) {
+			printk(KERN_WARNING
+			       "B%d receive queue overflow - flushing!\n",
+			       bch->nr);
+			skb_queue_purge(&bch->rqueue);
+		}
+		bch->rcount++;
+		skb_queue_tail(&bch->rqueue, bch->rx_skb);
+		bch->rx_skb = NULL;
+		schedule_event(bch, FLG_RECVQUEUE);
+	}
+}
+EXPORT_SYMBOL(recv_Bchannel);
+
+void
+recv_Dchannel_skb(struct dchannel *dch, struct sk_buff *skb)
+{
+	skb_queue_tail(&dch->rqueue, skb);
+	schedule_event(dch, FLG_RECVQUEUE);
+}
+EXPORT_SYMBOL(recv_Dchannel_skb);
+
+void
+recv_Bchannel_skb(struct bchannel *bch, struct sk_buff *skb)
+{
+	if (bch->rcount >= 64) {
+		printk(KERN_WARNING "B-channel %p receive queue overflow, "
+		       "flushing!\n", bch);
+		skb_queue_purge(&bch->rqueue);
+		bch->rcount = 0;
+	}
+	bch->rcount++;
+	skb_queue_tail(&bch->rqueue, skb);
+	schedule_event(bch, FLG_RECVQUEUE);
+}
+EXPORT_SYMBOL(recv_Bchannel_skb);
+
+static void
+confirm_Dsend(struct dchannel *dch)
+{
+	struct sk_buff	*skb;
+
+	skb = _alloc_mISDN_skb(PH_DATA_CNF, mISDN_HEAD_ID(dch->tx_skb),
+			       0, NULL, GFP_ATOMIC);
+	if (!skb) {
+		printk(KERN_ERR "%s: no skb id %x\n", __func__,
+		       mISDN_HEAD_ID(dch->tx_skb));
+		return;
+	}
+	skb_queue_tail(&dch->rqueue, skb);
+	schedule_event(dch, FLG_RECVQUEUE);
+}
+
+int
+get_next_dframe(struct dchannel *dch)
+{
+	dch->tx_idx = 0;
+	dch->tx_skb = skb_dequeue(&dch->squeue);
+	if (dch->tx_skb) {
+		confirm_Dsend(dch);
+		return 1;
+	}
+	dch->tx_skb = NULL;
+	test_and_clear_bit(FLG_TX_BUSY, &dch->Flags);
+	return 0;
+}
+EXPORT_SYMBOL(get_next_dframe);
+
+static void
+confirm_Bsend(struct bchannel *bch)
+{
+	struct sk_buff	*skb;
+
+	if (bch->rcount >= 64) {
+		printk(KERN_WARNING "B-channel %p receive queue overflow, "
+		       "flushing!\n", bch);
+		skb_queue_purge(&bch->rqueue);
+		bch->rcount = 0;
+	}
+	skb = _alloc_mISDN_skb(PH_DATA_CNF, mISDN_HEAD_ID(bch->tx_skb),
+			       0, NULL, GFP_ATOMIC);
+	if (!skb) {
+		printk(KERN_ERR "%s: no skb id %x\n", __func__,
+		       mISDN_HEAD_ID(bch->tx_skb));
+		return;
+	}
+	bch->rcount++;
+	skb_queue_tail(&bch->rqueue, skb);
+	schedule_event(bch, FLG_RECVQUEUE);
+}
+
+int
+get_next_bframe(struct bchannel *bch)
+{
+	bch->tx_idx = 0;
+	if (test_bit(FLG_TX_NEXT, &bch->Flags)) {
+		bch->tx_skb = bch->next_skb;
+		if (bch->tx_skb) {
+			bch->next_skb = NULL;
+			test_and_clear_bit(FLG_TX_NEXT, &bch->Flags);
+			/* confirm imediately to allow next data */
+			confirm_Bsend(bch);
+			return 1;
+		} else {
+			test_and_clear_bit(FLG_TX_NEXT, &bch->Flags);
+			printk(KERN_WARNING "B TX_NEXT without skb\n");
+		}
+	}
+	bch->tx_skb = NULL;
+	test_and_clear_bit(FLG_TX_BUSY, &bch->Flags);
+	return 0;
+}
+EXPORT_SYMBOL(get_next_bframe);
+
+void
+queue_ch_frame(struct mISDNchannel *ch, u_int pr, int id, struct sk_buff *skb)
+{
+	struct mISDNhead *hh;
+
+	if (!skb) {
+		_queue_data(ch, pr, id, 0, NULL, GFP_ATOMIC);
+	} else {
+		if (ch->peer) {
+			hh = mISDN_HEAD_P(skb);
+			hh->prim = pr;
+			hh->id = id;
+			if (!ch->recv(ch->peer, skb))
+				return;
+		}
+		dev_kfree_skb(skb);
+	}
+}
+EXPORT_SYMBOL(queue_ch_frame);
+
+int
+dchannel_senddata(struct dchannel *ch, struct sk_buff *skb)
+{
+	/* check oversize */
+	if (skb->len <= 0) {
+		printk(KERN_WARNING "%s: skb too small\n", __func__);
+		return -EINVAL;
+	}
+	if (skb->len > ch->maxlen) {
+		printk(KERN_WARNING "%s: skb too large(%d/%d)\n",
+		       __func__, skb->len, ch->maxlen);
+		return -EINVAL;
+	}
+	/* HW lock must be obtained */
+	if (test_and_set_bit(FLG_TX_BUSY, &ch->Flags)) {
+		skb_queue_tail(&ch->squeue, skb);
+		return 0;
+	} else {
+		/* write to fifo */
+		ch->tx_skb = skb;
+		ch->tx_idx = 0;
+		return 1;
+	}
+}
+EXPORT_SYMBOL(dchannel_senddata);
+
+int
+bchannel_senddata(struct bchannel *ch, struct sk_buff *skb)
+{
+
+	/* check oversize */
+	if (skb->len <= 0) {
+		printk(KERN_WARNING "%s: skb too small\n", __func__);
+		return -EINVAL;
+	}
+	if (skb->len > ch->maxlen) {
+		printk(KERN_WARNING "%s: skb too large(%d/%d)\n",
+		       __func__, skb->len, ch->maxlen);
+		return -EINVAL;
+	}
+	/* HW lock must be obtained */
+	/* check for pending next_skb */
+	if (ch->next_skb) {
+		printk(KERN_WARNING
+		       "%s: next_skb exist ERROR (skb->len=%d next_skb->len=%d)\n",
+		       __func__, skb->len, ch->next_skb->len);
+		return -EBUSY;
+	}
+	if (test_and_set_bit(FLG_TX_BUSY, &ch->Flags)) {
+		test_and_set_bit(FLG_TX_NEXT, &ch->Flags);
+		ch->next_skb = skb;
+		return 0;
+	} else {
+		/* write to fifo */
+		ch->tx_skb = skb;
+		ch->tx_idx = 0;
+		confirm_Bsend(ch);
+		return 1;
+	}
+}
+EXPORT_SYMBOL(bchannel_senddata);
+
+/* The function allocates a new receive skb on demand with a size for the
+ * requirements of the current protocol. It returns the tailroom of the
+ * receive skb or an error.
+ */
+int
+bchannel_get_rxbuf(struct bchannel *bch, int reqlen)
+{
+	int len;
+
+	if (bch->rx_skb) {
+		len = skb_tailroom(bch->rx_skb);
+		if (len < reqlen) {
+			pr_warning("B%d no space for %d (only %d) bytes\n",
+				   bch->nr, reqlen, len);
+			if (test_bit(FLG_TRANSPARENT, &bch->Flags)) {
+				/* send what we have now and try a new buffer */
+				recv_Bchannel(bch, 0, true);
+			} else {
+				/* on HDLC we have to drop too big frames */
+				return -EMSGSIZE;
+			}
+		} else {
+			return len;
+		}
+	}
+	/* update current min/max length first */
+	if (unlikely(bch->maxlen != bch->next_maxlen))
+		bch->maxlen = bch->next_maxlen;
+	if (unlikely(bch->minlen != bch->next_minlen))
+		bch->minlen = bch->next_minlen;
+	if (unlikely(reqlen > bch->maxlen))
+		return -EMSGSIZE;
+	if (test_bit(FLG_TRANSPARENT, &bch->Flags)) {
+		if (reqlen >= bch->minlen) {
+			len = reqlen;
+		} else {
+			len = 2 * bch->minlen;
+			if (len > bch->maxlen)
+				len = bch->maxlen;
+		}
+	} else {
+		/* with HDLC we do not know the length yet */
+		len = bch->maxlen;
+	}
+	bch->rx_skb = mI_alloc_skb(len, GFP_ATOMIC);
+	if (!bch->rx_skb) {
+		pr_warning("B%d receive no memory for %d bytes\n",
+			   bch->nr, len);
+		len = -ENOMEM;
+	}
+	return len;
+}
+EXPORT_SYMBOL(bchannel_get_rxbuf);