[PATCH V3] firmware: ti_sci: fix the secure_hdr in do_xfer

[Dhruva Gole]

The secure_hdr needs to be 0 init-ed however this was never being put
into the secure_buf, leading to possibility of the first 4 bytes of
secure_buf being possibly garbage.

Fix this by initialising the secure_hdr itself to the secure_buf
location, thus when we make it 0, it automatically ensures the first 4
bytes are 0.

Fixes: 32cd25128bd849 ("firmware: Add basic support for TI System Control Interface (TI SCI)")
Signed-off-by: Dhruva Gole <d-gole at ti.com>
---

Boot tested for sanity on AM62x SK
https://gist.github.com/DhruvaG2000/724ceba3a0db03f4b0bff47de1160074

Changelog:
v2 --> v3
Address Kamlesh's comment on v2: use sizeof(struct ti_sci_secure_msg_hdr)

v1 --> v2:
Rebased on top of latest master branch

Cc: Nishanth Menon <nm at ti.com>
Cc: Tom Rini <trini at konsulko.com>
Cc: Neha Francis <n-francis at ti.com>
Cc: Manorit Chawdhry <m-chawdhry at ti.com>
Cc: Vignesh Raghavendra <vigneshr at ti.com>
Cc: Kamlesh Gurudasani <kamlesh at ti.com>

---

 drivers/firmware/ti_sci.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/firmware/ti_sci.c b/drivers/firmware/ti_sci.c
index 6e9f93e9a302..49d2696a6d09 100644
--- a/drivers/firmware/ti_sci.c
+++ b/drivers/firmware/ti_sci.c
@@ -236,21 +236,21 @@ static int ti_sci_do_xfer(struct ti_sci_info *info,
 {
 	struct k3_sec_proxy_msg *msg = &xfer->tx_message;
 	u8 secure_buf[info->desc->max_msg_size];
-	struct ti_sci_secure_msg_hdr secure_hdr;
+	struct ti_sci_secure_msg_hdr *secure_hdr = (struct ti_sci_secure_msg_hdr *)secure_buf;
 	int ret;
 
 	if (info->is_secure) {
 		/* ToDo: get checksum of the entire message */
-		secure_hdr.checksum = 0;
-		secure_hdr.reserved = 0;
-		memcpy(&secure_buf[sizeof(secure_hdr)], xfer->tx_message.buf,
+		secure_hdr->checksum = 0;
+		secure_hdr->reserved = 0;
+		memcpy(&secure_buf[sizeof(struct ti_sci_secure_msg_hdr)], xfer->tx_message.buf,
 		       xfer->tx_message.len);
 
 		xfer->tx_message.buf = (u32 *)secure_buf;
-		xfer->tx_message.len += sizeof(secure_hdr);
+		xfer->tx_message.len += sizeof(struct ti_sci_secure_msg_hdr);
 
 		if (xfer->rx_len)
-			xfer->rx_len += sizeof(secure_hdr);
+			xfer->rx_len += sizeof(struct ti_sci_secure_msg_hdr);
 	}
 
 	/* Send the message */

base-commit: 15e7927b5a2d33666af19879577bf0c30ab088fe
-- 
2.34.1