1 files changed, 692 insertions, 33 deletions

diff --git a/drivers/tty/hvc/hvc_vio.c b/drivers/tty/hvc/hvc_vio.c
index e6eea148524..d4e0850e805 100644
--- a/drivers/tty/hvc/hvc_vio.c
+++ b/drivers/tty/hvc/hvc_vio.c
@@ -27,15 +27,27 @@
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ * TODO:
+ *
+ *   - handle error in sending hvsi protocol packets
+ *   - retry nego on subsequent sends ?
  */
 
+#undef DEBUG
+
 #include <linux/types.h>
 #include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/console.h>
 
 #include <asm/hvconsole.h>
 #include <asm/vio.h>
 #include <asm/prom.h>
 #include <asm/firmware.h>
+#include <asm/hvsi.h>
+#include <asm/udbg.h>
 
 #include "hvc_console.h"
 
@@ -43,14 +55,47 @@ static const char hvc_driver_name[] = "hvc_console";
 
 static struct vio_device_id hvc_driver_table[] __devinitdata = {
 	{"serial", "hvterm1"},
+#ifndef HVC_OLD_HVSI
+	{"serial", "hvterm-protocol"},
+#endif
 	{ "", "" }
 };
 MODULE_DEVICE_TABLE(vio, hvc_driver_table);
 
-static int filtered_get_chars(uint32_t vtermno, char *buf, int count)
+typedef enum hv_protocol {
+	HV_PROTOCOL_RAW,
+	HV_PROTOCOL_HVSI
+} hv_protocol_t;
+
+#define HV_INBUF_SIZE		255
+
+struct hvterm_priv {
+	u32		termno;		/* HV term number */
+	hv_protocol_t	proto;		/* Raw data or HVSI packets */
+	unsigned int	inbuf_len;	/* Data in input buffer */
+	unsigned char	inbuf[HV_INBUF_SIZE];
+	unsigned int	inbuf_cur;	/* Cursor in input buffer */
+	unsigned int	inbuf_pktlen;	/* HVSI packet lenght from cursor */
+	atomic_t	seqno;		/* HVSI packet sequence number */
+	unsigned int	opened:1;	/* HVSI driver opened */
+	unsigned int	established:1;	/* HVSI protocol established */
+	unsigned int 	is_console:1;	/* Used as a kernel console device */
+	unsigned int	mctrl_update:1;	/* HVSI modem control updated */
+	unsigned short	mctrl;		/* HVSI modem control */
+	struct tty_struct *tty;		/* TTY structure */
+};
+static struct hvterm_priv *hvterm_privs[MAX_NR_HVC_CONSOLES];
+
+/* For early boot console */
+static struct hvterm_priv hvterm_priv0;
+
+static int hvterm_raw_get_chars(uint32_t vtermno, char *buf, int count)
 {
-	unsigned long got;
-	int i;
+	struct hvterm_priv *pv = hvterm_privs[vtermno];
+	unsigned long got, i;
+
+	if (WARN_ON(!pv))
+		return 0;
 
 	/*
 	 * Vio firmware will read up to SIZE_VIO_GET_CHARS at its own discretion
@@ -60,7 +105,7 @@ static int filtered_get_chars(uint32_t vtermno, char *buf, int count)
 	if (count < SIZE_VIO_GET_CHARS)
 		return -EAGAIN;
 
-	got = hvc_get_chars(vtermno, buf, count);
+	got = hvc_get_chars(pv->termno, buf, count);
 
 	/*
 	 * Work around a HV bug where it gives us a null
@@ -70,32 +115,527 @@ static int filtered_get_chars(uint32_t vtermno, char *buf, int count)
 		if (buf[i] == 0 && buf[i-1] == '\r') {
 			--got;
 			if (i < got)
-				memmove(&buf[i], &buf[i+1],
-					got - i);
+				memmove(&buf[i], &buf[i+1], got - i);
 		}
 	}
 	return got;
 }
 
-static const struct hv_ops hvc_get_put_ops = {
-	.get_chars = filtered_get_chars,
-	.put_chars = hvc_put_chars,
+static int hvterm_raw_put_chars(uint32_t vtermno, const char *buf, int count)
+{
+	struct hvterm_priv *pv = hvterm_privs[vtermno];
+
+	if (WARN_ON(!pv))
+		return 0;
+
+	return hvc_put_chars(pv->termno, buf, count);
+}
+
+static const struct hv_ops hvterm_raw_ops = {
+	.get_chars = hvterm_raw_get_chars,
+	.put_chars = hvterm_raw_put_chars,
 	.notifier_add = notifier_add_irq,
 	.notifier_del = notifier_del_irq,
 	.notifier_hangup = notifier_hangup_irq,
 };
 
+static int hvterm_hvsi_send_packet(struct hvterm_priv *pv, struct hvsi_header *packet)
+{
+	packet->seqno = atomic_inc_return(&pv->seqno);
+
+	/* Assumes that always succeeds, works in practice */
+	return hvc_put_chars(pv->termno, (char *)packet, packet->len);
+}
+
+static void hvterm_hvsi_start_handshake(struct hvterm_priv *pv)
+{
+	struct hvsi_query q;
+
+	/* Reset state */
+	pv->established = 0;
+	atomic_set(&pv->seqno, 0);
+
+	pr_devel("HVSI@%x: Handshaking started\n", pv->termno);
+
+	/* Send version query */
+	q.hdr.type = VS_QUERY_PACKET_HEADER;
+	q.hdr.len = sizeof(struct hvsi_query);
+	q.verb = VSV_SEND_VERSION_NUMBER;
+	hvterm_hvsi_send_packet(pv, &q.hdr);
+}
+
+static int hvterm_hvsi_send_close(struct hvterm_priv *pv)
+{
+	struct hvsi_control ctrl;
+
+	pv->established = 0;
+
+	ctrl.hdr.type = VS_CONTROL_PACKET_HEADER;
+	ctrl.hdr.len = sizeof(struct hvsi_control);
+	ctrl.verb = VSV_CLOSE_PROTOCOL;
+	return hvterm_hvsi_send_packet(pv, &ctrl.hdr);
+}
+
+static void hvterm_cd_change(struct hvterm_priv *pv, int cd)
+{
+	if (cd)
+		pv->mctrl |= TIOCM_CD;
+	else {
+		pv->mctrl &= ~TIOCM_CD;
+
+		/* We copy the existing hvsi driver semantics
+		 * here which are to trigger a hangup when
+		 * we get a carrier loss.
+		 * Closing our connection to the server will
+		 * do just that.
+		 */
+		if (!pv->is_console && pv->opened) {
+			pr_devel("HVSI@%x Carrier lost, hanging up !\n",
+				 pv->termno);
+			hvterm_hvsi_send_close(pv);
+		}
+	}
+}
+
+static void hvterm_hvsi_got_control(struct hvterm_priv *pv)
+{
+	struct hvsi_control *pkt = (struct hvsi_control *)pv->inbuf;
+
+	switch (pkt->verb) {
+	case VSV_CLOSE_PROTOCOL:
+		/* We restart the handshaking */
+		hvterm_hvsi_start_handshake(pv);
+		break;
+	case VSV_MODEM_CTL_UPDATE:
+		/* Transition of carrier detect */
+		hvterm_cd_change(pv, pkt->word & HVSI_TSCD);
+		break;
+	}
+}
+
+static void hvterm_hvsi_got_query(struct hvterm_priv *pv)
+{
+	struct hvsi_query *pkt = (struct hvsi_query *)pv->inbuf;
+	struct hvsi_query_response r;
+
+	/* We only handle version queries */
+	if (pkt->verb != VSV_SEND_VERSION_NUMBER)
+		return;
+
+	pr_devel("HVSI@%x: Got version query, sending response...\n",
+		 pv->termno);
+
+	/* Send version response */
+	r.hdr.type = VS_QUERY_RESPONSE_PACKET_HEADER;
+	r.hdr.len = sizeof(struct hvsi_query_response);
+	r.verb = VSV_SEND_VERSION_NUMBER;
+	r.u.version = HVSI_VERSION;
+	r.query_seqno = pkt->hdr.seqno;
+	hvterm_hvsi_send_packet(pv, &r.hdr);
+
+	/* Assume protocol is open now */
+	pv->established = 1;
+}
+
+static void hvterm_hvsi_got_response(struct hvterm_priv *pv)
+{
+	struct hvsi_query_response *r = (struct hvsi_query_response *)pv->inbuf;
+
+	switch(r->verb) {
+	case VSV_SEND_MODEM_CTL_STATUS:
+		hvterm_cd_change(pv, r->u.mctrl_word & HVSI_TSCD);
+		pv->mctrl_update = 1;
+		break;
+	}
+}
+
+static int hvterm_hvsi_check_packet(struct hvterm_priv *pv)
+{
+	u8 len, type;
+
+	/* Check header validity. If it's invalid, we ditch
+	 * the whole buffer and hope we eventually resync
+	 */
+	if (pv->inbuf[0] < 0xfc) {
+		pv->inbuf_len = pv->inbuf_pktlen = 0;
+		return 0;
+	}
+	type = pv->inbuf[0];
+	len = pv->inbuf[1];
+
+	/* Packet incomplete ? */
+	if (pv->inbuf_len < len)
+		return 0;
+
+	pr_devel("HVSI@%x: Got packet type %x len %d bytes:\n",
+		 pv->termno, type, len);
+
+	/* We have a packet, yay ! Handle it */
+	switch(type) {
+	case VS_DATA_PACKET_HEADER:
+		pv->inbuf_pktlen = len - 4;
+		pv->inbuf_cur = 4;
+		return 1;
+	case VS_CONTROL_PACKET_HEADER:
+		hvterm_hvsi_got_control(pv);
+		break;
+	case VS_QUERY_PACKET_HEADER:
+		hvterm_hvsi_got_query(pv);
+		break;
+	case VS_QUERY_RESPONSE_PACKET_HEADER:
+		hvterm_hvsi_got_response(pv);
+		break;
+	}
+
+	/* Swallow packet and retry */
+	pv->inbuf_len -= len;
+	memmove(pv->inbuf, &pv->inbuf[len], pv->inbuf_len);
+	return 1;
+}
+
+static int hvterm_hvsi_get_packet(struct hvterm_priv *pv)
+{
+	/* If we have room in the buffer, ask HV for more */
+	if (pv->inbuf_len < HV_INBUF_SIZE)
+		pv->inbuf_len += hvc_get_chars(pv->termno,
+					       &pv->inbuf[pv->inbuf_len],
+					       HV_INBUF_SIZE - pv->inbuf_len);
+	/*
+	 * If we have at least 4 bytes in the buffer, check for
+	 * a full packet and retry
+	 */
+	if (pv->inbuf_len >= 4)
+		return hvterm_hvsi_check_packet(pv);
+	return 0;
+}
+
+static int hvterm_hvsi_get_chars(uint32_t vtermno, char *buf, int count)
+{
+	struct hvterm_priv *pv = hvterm_privs[vtermno];
+	unsigned int tries, read = 0;
+
+	if (WARN_ON(!pv))
+		return 0;
+
+	/* If we aren't open, dont do anything in order to avoid races
+	 * with connection establishment. The hvc core will call this
+	 * before we have returned from notifier_add(), and we need to
+	 * avoid multiple users playing with the receive buffer
+	 */
+	if (!pv->opened)
+		return 0;
+
+	/* We try twice, once with what data we have and once more
+	 * after we try to fetch some more from the hypervisor
+	 */
+	for (tries = 1; count && tries < 2; tries++) {
+		/* Consume existing data packet */
+		if (pv->inbuf_pktlen) {
+			unsigned int l = min(count, (int)pv->inbuf_pktlen);
+			memcpy(&buf[read], &pv->inbuf[pv->inbuf_cur], l);
+			pv->inbuf_cur += l;
+			pv->inbuf_pktlen -= l;
+			count -= l;
+			read += l;
+		}
+		if (count == 0)
+			break;
+
+		/* Data packet fully consumed, move down remaning data */
+		if (pv->inbuf_cur) {
+			pv->inbuf_len -= pv->inbuf_cur;
+			memmove(pv->inbuf, &pv->inbuf[pv->inbuf_cur], pv->inbuf_len);
+			pv->inbuf_cur = 0;
+		}
+
+		/* Try to get another packet */
+		if (hvterm_hvsi_get_packet(pv))
+			tries--;
+	}
+	if (!pv->established) {
+		pr_devel("HVSI@%x: returning -EPIPE\n", pv->termno);
+		return -EPIPE;
+	}
+	return read;
+}
+
+static int hvterm_hvsi_put_chars(uint32_t vtermno, const char *buf, int count)
+{
+	struct hvterm_priv *pv = hvterm_privs[vtermno];
+	struct hvsi_data dp;
+	int rc, adjcount = min(count, HVSI_MAX_OUTGOING_DATA);
+
+	if (WARN_ON(!pv))
+		return 0;
+
+	dp.hdr.type = VS_DATA_PACKET_HEADER;
+	dp.hdr.len = adjcount + sizeof(struct hvsi_header);
+	memcpy(dp.data, buf, adjcount);
+	rc = hvterm_hvsi_send_packet(pv, &dp.hdr);
+	if (rc <= 0)
+		return rc;
+	return adjcount;
+}
+
+static void maybe_msleep(unsigned long ms)
+{
+	/* During early boot, IRQs are disabled, use mdelay */
+	if (irqs_disabled())
+		mdelay(ms);
+	else
+		msleep(ms);
+}
+
+static int hvterm_hvsi_read_mctrl(struct hvterm_priv *pv)
+{
+	struct hvsi_query q;
+	int rc, timeout;
+
+	pr_devel("HVSI@%x: Querying modem control status...\n",
+		 pv->termno);
+
+	pv->mctrl_update = 0;
+	q.hdr.type = VS_QUERY_PACKET_HEADER;
+	q.hdr.len = sizeof(struct hvsi_query);
+	q.hdr.seqno = atomic_inc_return(&pv->seqno);
+	q.verb = VSV_SEND_MODEM_CTL_STATUS;
+	rc = hvterm_hvsi_send_packet(pv, &q.hdr);
+	if (rc <= 0) {
+		pr_devel("HVSI@%x: Error %d...\n", pv->termno, rc);
+		return rc;
+	}
+
+	/* Try for up to 1s */
+	for (timeout = 0; timeout < 1000; timeout++) {
+		if (!pv->established)
+			return -ENXIO;
+		if (pv->mctrl_update)
+			return 0;
+		if (!hvterm_hvsi_get_packet(pv))
+			maybe_msleep(1);
+	}
+	return -EIO;
+}
+
+static int hvterm_hvsi_write_mctrl(struct hvterm_priv *pv, int dtr)
+{
+	struct hvsi_control ctrl;
+
+	pr_devel("HVSI@%x: %s DTR...\n", pv->termno,
+		 dtr ? "Setting" : "Clearing");
+
+	ctrl.hdr.type = VS_CONTROL_PACKET_HEADER,
+	ctrl.hdr.len = sizeof(struct hvsi_control);
+	ctrl.verb = VSV_SET_MODEM_CTL;
+	ctrl.mask = HVSI_TSDTR;
+	ctrl.word = dtr ? HVSI_TSDTR : 0;
+	if (dtr)
+		pv->mctrl |= TIOCM_DTR;
+	else
+		pv->mctrl &= ~TIOCM_DTR;
+	return hvterm_hvsi_send_packet(pv, &ctrl.hdr);
+}
+
+static void hvterm_hvsi_establish(struct hvterm_priv *pv)
+{
+	int timeout;
+
+	/* Try for up to 10ms, there can be a packet to
+	 * start the process waiting for us...
+	 */
+	for (timeout = 0; timeout < 10; timeout++) {
+		if (pv->established)
+			goto established;
+		if (!hvterm_hvsi_get_packet(pv))
+			maybe_msleep(1);
+	}
+
+	/* Failed, send a close connection packet just
+	 * in case
+	 */
+	hvterm_hvsi_send_close(pv);
+
+	/* Then restart handshake */
+	hvterm_hvsi_start_handshake(pv);
+
+	/* Try for up to 100ms */
+	for (timeout = 0; timeout < 100; timeout++) {
+		if (pv->established)
+			goto established;
+		if (!hvterm_hvsi_get_packet(pv))
+			maybe_msleep(1);
+	}
+
+	if (!pv->established) {
+		pr_devel("HVSI@%x: Timeout handshaking, giving up !\n",
+			 pv->termno);
+		return;
+	}
+ established:
+	/* Query modem control lines */
+	hvterm_hvsi_read_mctrl(pv);
+
+	/* Set our own DTR */
+	hvterm_hvsi_write_mctrl(pv, 1);
+
+	/* Set the opened flag so reads are allowed */
+	wmb();
+	pv->opened = 1;
+}
+
+static int hvterm_hvsi_open(struct hvc_struct *hp, int data)
+{
+	struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
+	int rc;
+
+	pr_devel("HVSI@%x: open !\n", pv->termno);
+
+	rc = notifier_add_irq(hp, data);
+	if (rc)
+		return rc;
+
+	/* Keep track of the tty data structure */
+	pv->tty = tty_kref_get(hp->tty);
+
+	hvterm_hvsi_establish(pv);
+	return 0;
+}
+
+static void hvterm_hvsi_shutdown(struct hvc_struct *hp, struct hvterm_priv *pv)
+{
+	unsigned long flags;
+
+	if (!pv->is_console) {
+		pr_devel("HVSI@%x: Not a console, tearing down\n",
+			 pv->termno);
+
+		/* Clear opened, synchronize with khvcd */
+		spin_lock_irqsave(&hp->lock, flags);
+		pv->opened = 0;
+		spin_unlock_irqrestore(&hp->lock, flags);
+
+		/* Clear our own DTR */
+		if (!pv->tty || (pv->tty->termios->c_cflag & HUPCL))
+			hvterm_hvsi_write_mctrl(pv, 0);
+
+		/* Tear down the connection */
+		hvterm_hvsi_send_close(pv);
+	}
+
+	if (pv->tty)
+		tty_kref_put(pv->tty);
+	pv->tty = NULL;
+}
+
+static void hvterm_hvsi_close(struct hvc_struct *hp, int data)
+{
+	struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
+
+	pr_devel("HVSI@%x: close !\n", pv->termno);
+
+	hvterm_hvsi_shutdown(hp, pv);
+
+	notifier_del_irq(hp, data);
+}
+
+void hvterm_hvsi_hangup(struct hvc_struct *hp, int data)
+{
+	struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
+
+	pr_devel("HVSI@%x: hangup !\n", pv->termno);
+
+	hvterm_hvsi_shutdown(hp, pv);
+
+	notifier_hangup_irq(hp, data);
+}
+
+static int hvterm_hvsi_tiocmget(struct hvc_struct *hp)
+{
+	struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
+
+	if (!pv)
+		return -EINVAL;
+	return pv->mctrl;
+}
+
+static int hvterm_hvsi_tiocmset(struct hvc_struct *hp, unsigned int set,
+				unsigned int clear)
+{
+	struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
+
+	pr_devel("HVSI@%x: Set modem control, set=%x,clr=%x\n",
+		 pv->termno, set, clear);
+
+	if (set & TIOCM_DTR)
+		hvterm_hvsi_write_mctrl(pv, 1);
+	else if (clear & TIOCM_DTR)
+		hvterm_hvsi_write_mctrl(pv, 0);
+
+	return 0;
+}
+
+static const struct hv_ops hvterm_hvsi_ops = {
+	.get_chars = hvterm_hvsi_get_chars,
+	.put_chars = hvterm_hvsi_put_chars,
+	.notifier_add = hvterm_hvsi_open,
+	.notifier_del = hvterm_hvsi_close,
+	.notifier_hangup = hvterm_hvsi_hangup,
+	.tiocmget = hvterm_hvsi_tiocmget,
+	.tiocmset = hvterm_hvsi_tiocmset,
+};
+
 static int __devinit hvc_vio_probe(struct vio_dev *vdev,
-				const struct vio_device_id *id)
+				   const struct vio_device_id *id)
 {
+	const struct hv_ops *ops;
 	struct hvc_struct *hp;
+	struct hvterm_priv *pv;
+	hv_protocol_t proto;
+	int i, termno = -1;
 
 	/* probed with invalid parameters. */
 	if (!vdev || !id)
 		return -EPERM;
 
-	hp = hvc_alloc(vdev->unit_address, vdev->irq, &hvc_get_put_ops,
-			MAX_VIO_PUT_CHARS);
+	if (of_device_is_compatible(vdev->dev.of_node, "hvterm1")) {
+		proto = HV_PROTOCOL_RAW;
+		ops = &hvterm_raw_ops;
+	} else if (of_device_is_compatible(vdev->dev.of_node, "hvterm-protocol")) {
+		proto = HV_PROTOCOL_HVSI;
+		ops = &hvterm_hvsi_ops;
+	} else {
+		pr_err("hvc_vio: Unkown protocol for %s\n", vdev->dev.of_node->full_name);
+		return -ENXIO;
+	}
+
+	pr_devel("hvc_vio_probe() device %s, using %s protocol\n",
+		 vdev->dev.of_node->full_name,
+		 proto == HV_PROTOCOL_RAW ? "raw" : "hvsi");
+
+	/* Is it our boot one ? */
+	if (hvterm_privs[0] == &hvterm_priv0 &&
+	    vdev->unit_address == hvterm_priv0.termno) {
+		pv = hvterm_privs[0];
+		termno = 0;
+		pr_devel("->boot console, using termno 0\n");
+	}
+	/* nope, allocate a new one */
+	else {
+		for (i = 0; i < MAX_NR_HVC_CONSOLES && termno < 0; i++)
+			if (!hvterm_privs[i])
+				termno = i;
+		pr_devel("->non-boot console, using termno %d\n", termno);
+		if (termno < 0)
+			return -ENODEV;
+		pv = kzalloc(sizeof(struct hvterm_priv), GFP_KERNEL);
+		if (!pv)
+			return -ENOMEM;
+		pv->termno = vdev->unit_address;
+		pv->proto = proto;
+		hvterm_privs[termno] = pv;
+	}
+
+	hp = hvc_alloc(termno, vdev->irq, ops, MAX_VIO_PUT_CHARS);
 	if (IS_ERR(hp))
 		return PTR_ERR(hp);
 	dev_set_drvdata(&vdev->dev, hp);
@@ -106,8 +646,16 @@ static int __devinit hvc_vio_probe(struct vio_dev *vdev,
 static int __devexit hvc_vio_remove(struct vio_dev *vdev)
 {
 	struct hvc_struct *hp = dev_get_drvdata(&vdev->dev);
+	int rc, termno;
 
-	return hvc_remove(hp);
+	termno = hp->vtermno;
+	rc = hvc_remove(hp);
+	if (rc == 0) {
+		if (hvterm_privs[termno] != &hvterm_priv0)
+			kfree(hvterm_privs[termno]);
+		hvterm_privs[termno] = NULL;
+	}
+	return rc;
 }
 
 static struct vio_driver hvc_vio_driver = {
@@ -140,34 +688,145 @@ static void __exit hvc_vio_exit(void)
 }
 module_exit(hvc_vio_exit);
 
-/* the device tree order defines our numbering */
-static int hvc_find_vtys(void)
+static void udbg_hvc_putc(char c)
 {
-	struct device_node *vty;
-	int num_found = 0;
+	int count = -1;
 
-	for (vty = of_find_node_by_name(NULL, "vty"); vty != NULL;
-			vty = of_find_node_by_name(vty, "vty")) {
-		const uint32_t *vtermno;
+	if (c == '\n')
+		udbg_hvc_putc('\r');
 
-		/* We have statically defined space for only a certain number
-		 * of console adapters.
-		 */
-		if (num_found >= MAX_NR_HVC_CONSOLES) {
-			of_node_put(vty);
+	do {
+		switch(hvterm_priv0.proto) {
+		case HV_PROTOCOL_RAW:
+			count = hvterm_raw_put_chars(0, &c, 1);
+			break;
+		case HV_PROTOCOL_HVSI:
+			count = hvterm_hvsi_put_chars(0, &c, 1);
 			break;
 		}
+	} while(count == 0);
+}
+
+static int udbg_hvc_getc_poll(void)
+{
+	int rc = 0;
+	char c;
 
-		vtermno = of_get_property(vty, "reg", NULL);
-		if (!vtermno)
-			continue;
+	switch(hvterm_priv0.proto) {
+	case HV_PROTOCOL_RAW:
+		rc = hvterm_raw_get_chars(0, &c, 1);
+		break;
+	case HV_PROTOCOL_HVSI:
+		rc = hvterm_hvsi_get_chars(0, &c, 1);
+		break;
+	}
+	if (!rc)
+		return -1;
+	return c;
+}
 
-		if (of_device_is_compatible(vty, "hvterm1")) {
-			hvc_instantiate(*vtermno, num_found, &hvc_get_put_ops);
-			++num_found;
+static int udbg_hvc_getc(void)
+{
+	int ch;
+	for (;;) {
+		ch = udbg_hvc_getc_poll();
+		if (ch == -1) {
+			/* This shouldn't be needed...but... */
+			volatile unsigned long delay;
+			for (delay=0; delay < 2000000; delay++)
+				;
+		} else {
+			return ch;
 		}
 	}
+}
+
+void __init hvc_vio_init_early(void)
+{
+	struct device_node *stdout_node;
+	const u32 *termno;
+	const char *name;
+	const struct hv_ops *ops;
+
+	/* find the boot console from /chosen/stdout */
+	if (!of_chosen)
+		return;
+	name = of_get_property(of_chosen, "linux,stdout-path", NULL);
+	if (name == NULL)
+		return;
+	stdout_node = of_find_node_by_path(name);
+	if (!stdout_node)
+		return;
+	name = of_get_property(stdout_node, "name", NULL);
+	if (!name) {
+		printk(KERN_WARNING "stdout node missing 'name' property!\n");
+		goto out;
+	}
+
+	/* Check if it's a virtual terminal */
+	if (strncmp(name, "vty", 3) != 0)
+		goto out;
+	termno = of_get_property(stdout_node, "reg", NULL);
+	if (termno == NULL)
+		goto out;
+	hvterm_priv0.termno = *termno;
+	hvterm_priv0.is_console = 1;
+	hvterm_privs[0] = &hvterm_priv0;
+
+	/* Check the protocol */
+	if (of_device_is_compatible(stdout_node, "hvterm1")) {
+		hvterm_priv0.proto = HV_PROTOCOL_RAW;
+		ops = &hvterm_raw_ops;
+	}
+	else if (of_device_is_compatible(stdout_node, "hvterm-protocol")) {
+		hvterm_priv0.proto = HV_PROTOCOL_HVSI;
+		ops = &hvterm_hvsi_ops;
+		/* HVSI, perform the handshake now */
+		hvterm_hvsi_establish(&hvterm_priv0);
+	} else
+		goto out;
+	udbg_putc = udbg_hvc_putc;
+	udbg_getc = udbg_hvc_getc;
+	udbg_getc_poll = udbg_hvc_getc_poll;
+#ifdef HVC_OLD_HVSI
+	/* When using the old HVSI driver don't register the HVC
+	 * backend for HVSI, only do udbg
+	 */
+	if (hvterm_priv0.proto == HV_PROTOCOL_HVSI)
+		goto out;
+#endif
+	add_preferred_console("hvc", 0, NULL);
+	hvc_instantiate(0, 0, ops);
+out:
+	of_node_put(stdout_node);
+}
+
+/* call this from early_init() for a working debug console on
+ * vterm capable LPAR machines
+ */
+#ifdef CONFIG_PPC_EARLY_DEBUG_LPAR
+void __init udbg_init_debug_lpar(void)
+{
+	hvterm_privs[0] = &hvterm_priv0;
+	hvterm_priv0.termno = 0;
+	hvterm_priv0.proto = HV_PROTOCOL_RAW;
+	hvterm_priv0.is_console = 1;
+	udbg_putc = udbg_hvc_putc;
+	udbg_getc = udbg_hvc_getc;
+	udbg_getc_poll = udbg_hvc_getc_poll;
+}
+#endif /* CONFIG_PPC_EARLY_DEBUG_LPAR */
 
-	return num_found;
+#ifdef CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI
+void __init udbg_init_debug_lpar_hvsi(void)
+{
+	hvterm_privs[0] = &hvterm_priv0;
+	hvterm_priv0.termno = CONFIG_PPC_EARLY_DEBUG_HVSI_VTERMNO;
+	hvterm_priv0.proto = HV_PROTOCOL_HVSI;
+	hvterm_priv0.is_console = 1;
+	udbg_putc = udbg_hvc_putc;
+	udbg_getc = udbg_hvc_getc;
+	udbg_getc_poll = udbg_hvc_getc_poll;
+	hvterm_hvsi_establish(&hvterm_priv0);
 }
-console_initcall(hvc_find_vtys);
+#endif /* CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI */