[PATCH] powerpc/hvsi: Fix endianness issues in the HVSI driver

[Laurent Dufour]

This patch fixes several endianness issues detected when running the HVSI
driver in little endian mode.

These issues are raised in little endian mode because the data exchanged in
memory between the kernel and the hypervisor has to be in big endian
format.

Signed-off-by: Laurent Dufour <ldufour at linux.vnet.ibm.com>
CC: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
CC: Jiri Slaby <jslaby at suse.cz>
CC: linuxppc-dev at lists.ozlabs.org
CC: linux-kernel at vger.kernel.org
---
 drivers/tty/hvc/hvsi.c | 46 ++++++++++++++++++++++++----------------------
 1 file changed, 24 insertions(+), 22 deletions(-)

diff --git a/drivers/tty/hvc/hvsi.c b/drivers/tty/hvc/hvsi.c
index 41901997c0d6..a75146f600cb 100644
--- a/drivers/tty/hvc/hvsi.c
+++ b/drivers/tty/hvc/hvsi.c
@@ -240,9 +240,9 @@ static void hvsi_recv_control(struct hvsi_struct *hp, uint8_t *packet,
 {
 	struct hvsi_control *header = (struct hvsi_control *)packet;
 
-	switch (header->verb) {
+	switch (be16_to_cpu(header->verb)) {
 		case VSV_MODEM_CTL_UPDATE:
-			if ((header->word & HVSI_TSCD) == 0) {
+			if ((be32_to_cpu(header->word) & HVSI_TSCD) == 0) {
 				/* CD went away; no more connection */
 				pr_debug("hvsi%i: CD dropped\n", hp->index);
 				hp->mctrl &= TIOCM_CD;
@@ -267,6 +267,7 @@ static void hvsi_recv_control(struct hvsi_struct *hp, uint8_t *packet,
 static void hvsi_recv_response(struct hvsi_struct *hp, uint8_t *packet)
 {
 	struct hvsi_query_response *resp = (struct hvsi_query_response *)packet;
+	uint32_t mctrl_word;
 
 	switch (hp->state) {
 		case HVSI_WAIT_FOR_VER_RESPONSE:
@@ -274,9 +275,10 @@ static void hvsi_recv_response(struct hvsi_struct *hp, uint8_t *packet)
 			break;
 		case HVSI_WAIT_FOR_MCTRL_RESPONSE:
 			hp->mctrl = 0;
-			if (resp->u.mctrl_word & HVSI_TSDTR)
+			mctrl_word = be32_to_cpu(resp->u.mctrl_word);
+			if (mctrl_word & HVSI_TSDTR)
 				hp->mctrl |= TIOCM_DTR;
-			if (resp->u.mctrl_word & HVSI_TSCD)
+			if (mctrl_word & HVSI_TSCD)
 				hp->mctrl |= TIOCM_CD;
 			__set_state(hp, HVSI_OPEN);
 			break;
@@ -295,10 +297,10 @@ static int hvsi_version_respond(struct hvsi_struct *hp, uint16_t query_seqno)
 
 	packet.hdr.type = VS_QUERY_RESPONSE_PACKET_HEADER;
 	packet.hdr.len = sizeof(struct hvsi_query_response);
-	packet.hdr.seqno = atomic_inc_return(&hp->seqno);
-	packet.verb = VSV_SEND_VERSION_NUMBER;
+	packet.hdr.seqno = cpu_to_be16(atomic_inc_return(&hp->seqno));
+	packet.verb = cpu_to_be16(VSV_SEND_VERSION_NUMBER);
 	packet.u.version = HVSI_VERSION;
-	packet.query_seqno = query_seqno+1;
+	packet.query_seqno = cpu_to_be16(query_seqno+1);
 
 	pr_debug("%s: sending %i bytes\n", __func__, packet.hdr.len);
 	dbg_dump_hex((uint8_t*)&packet, packet.hdr.len);
@@ -319,7 +321,7 @@ static void hvsi_recv_query(struct hvsi_struct *hp, uint8_t *packet)
 
 	switch (hp->state) {
 		case HVSI_WAIT_FOR_VER_QUERY:
-			hvsi_version_respond(hp, query->hdr.seqno);
+			hvsi_version_respond(hp, be16_to_cpu(query->hdr.seqno));
 			__set_state(hp, HVSI_OPEN);
 			break;
 		default:
@@ -555,8 +557,8 @@ static int hvsi_query(struct hvsi_struct *hp, uint16_t verb)
 
 	packet.hdr.type = VS_QUERY_PACKET_HEADER;
 	packet.hdr.len = sizeof(struct hvsi_query);
-	packet.hdr.seqno = atomic_inc_return(&hp->seqno);
-	packet.verb = verb;
+	packet.hdr.seqno = cpu_to_be16(atomic_inc_return(&hp->seqno));
+	packet.verb = cpu_to_be16(verb);
 
 	pr_debug("%s: sending %i bytes\n", __func__, packet.hdr.len);
 	dbg_dump_hex((uint8_t*)&packet, packet.hdr.len);
@@ -596,14 +598,14 @@ static int hvsi_set_mctrl(struct hvsi_struct *hp, uint16_t mctrl)
 	struct hvsi_control packet __ALIGNED__;
 	int wrote;
 
-	packet.hdr.type = VS_CONTROL_PACKET_HEADER,
-	packet.hdr.seqno = atomic_inc_return(&hp->seqno);
+	packet.hdr.type = VS_CONTROL_PACKET_HEADER;
+	packet.hdr.seqno = cpu_to_be16(atomic_inc_return(&hp->seqno));
 	packet.hdr.len = sizeof(struct hvsi_control);
-	packet.verb = VSV_SET_MODEM_CTL;
-	packet.mask = HVSI_TSDTR;
+	packet.verb = cpu_to_be16(VSV_SET_MODEM_CTL);
+	packet.mask = cpu_to_be32(HVSI_TSDTR);
 
 	if (mctrl & TIOCM_DTR)
-		packet.word = HVSI_TSDTR;
+		packet.word = cpu_to_be32(HVSI_TSDTR);
 
 	pr_debug("%s: sending %i bytes\n", __func__, packet.hdr.len);
 	dbg_dump_hex((uint8_t*)&packet, packet.hdr.len);
@@ -680,7 +682,7 @@ static int hvsi_put_chars(struct hvsi_struct *hp, const char *buf, int count)
 	BUG_ON(count > HVSI_MAX_OUTGOING_DATA);
 
 	packet.hdr.type = VS_DATA_PACKET_HEADER;
-	packet.hdr.seqno = atomic_inc_return(&hp->seqno);
+	packet.hdr.seqno = cpu_to_be16(atomic_inc_return(&hp->seqno));
 	packet.hdr.len = count + sizeof(struct hvsi_header);
 	memcpy(&packet.data, buf, count);
 
@@ -697,9 +699,9 @@ static void hvsi_close_protocol(struct hvsi_struct *hp)
 	struct hvsi_control packet __ALIGNED__;
 
 	packet.hdr.type = VS_CONTROL_PACKET_HEADER;
-	packet.hdr.seqno = atomic_inc_return(&hp->seqno);
+	packet.hdr.seqno = cpu_to_be16(atomic_inc_return(&hp->seqno));
 	packet.hdr.len = 6;
-	packet.verb = VSV_CLOSE_PROTOCOL;
+	packet.verb = cpu_to_be16(VSV_CLOSE_PROTOCOL);
 
 	pr_debug("%s: sending %i bytes\n", __func__, packet.hdr.len);
 	dbg_dump_hex((uint8_t*)&packet, packet.hdr.len);
@@ -1180,7 +1182,7 @@ static int __init hvsi_console_init(void)
 	/* search device tree for vty nodes */
 	for_each_compatible_node(vty, "serial", "hvterm-protocol") {
 		struct hvsi_struct *hp;
-		const uint32_t *vtermno, *irq;
+		const __be32 *vtermno, *irq;
 
 		vtermno = of_get_property(vty, "reg", NULL);
 		irq = of_get_property(vty, "interrupts", NULL);
@@ -1202,11 +1204,11 @@ static int __init hvsi_console_init(void)
 		hp->index = hvsi_count;
 		hp->inbuf_end = hp->inbuf;
 		hp->state = HVSI_CLOSED;
-		hp->vtermno = *vtermno;
-		hp->virq = irq_create_mapping(NULL, irq[0]);
+		hp->vtermno = be32_to_cpup(vtermno);
+		hp->virq = irq_create_mapping(NULL, be32_to_cpup(irq));
 		if (hp->virq == 0) {
 			printk(KERN_ERR "%s: couldn't create irq mapping for 0x%x\n",
-				__func__, irq[0]);
+			       __func__, be32_to_cpup(irq));
 			tty_port_destroy(&hp->port);
 			continue;
 		}
-- 
1.9.1