Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/tty/hvc/Kconfig b/drivers/tty/hvc/Kconfig
index 4293c17..4d22b91 100644
--- a/drivers/tty/hvc/Kconfig
+++ b/drivers/tty/hvc/Kconfig
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 if TTY
 
 config HVC_DRIVER
@@ -24,7 +25,6 @@
 config HVC_OLD_HVSI
 	bool "Old driver for pSeries serial port (/dev/hvsi*)"
 	depends on HVC_CONSOLE
-	default n
 
 config HVC_OPAL
 	bool "OPAL Console support"
@@ -73,7 +73,6 @@
        bool "udbg based fake hypervisor console"
        depends on PPC
        select HVC_DRIVER
-       default n
        help
          This is meant to be used during HW bring up or debugging when
 	 no other console mechanism exist but udbg, to get you a quick
diff --git a/drivers/tty/hvc/hvc_opal.c b/drivers/tty/hvc/hvc_opal.c
index 77baf89..c664125 100644
--- a/drivers/tty/hvc/hvc_opal.c
+++ b/drivers/tty/hvc/hvc_opal.c
@@ -353,7 +353,7 @@
 		if (!opal)
 			return;
 		for_each_child_of_node(opal, np) {
-			if (!strcmp(np->name, "serial")) {
+			if (of_node_name_eq(np, "serial")) {
 				stdout_node = np;
 				break;
 			}
diff --git a/drivers/tty/hvc/hvc_riscv_sbi.c b/drivers/tty/hvc/hvc_riscv_sbi.c
index 75155bd..31f53fa 100644
--- a/drivers/tty/hvc/hvc_riscv_sbi.c
+++ b/drivers/tty/hvc/hvc_riscv_sbi.c
@@ -53,7 +53,6 @@
 static int __init hvc_sbi_console_init(void)
 {
 	hvc_instantiate(0, 0, &hvc_sbi_ops);
-	add_preferred_console("hvc", 0, NULL);
 
 	return 0;
 }
diff --git a/drivers/tty/hvc/hvc_vio.c b/drivers/tty/hvc/hvc_vio.c
index 59eaa62..7af54d6 100644
--- a/drivers/tty/hvc/hvc_vio.c
+++ b/drivers/tty/hvc/hvc_vio.c
@@ -107,6 +107,14 @@
 	return got;
 }
 
+/**
+ * hvterm_raw_put_chars: send characters to firmware for given vterm adapter
+ * @vtermno: The virtual terminal number.
+ * @buf: The characters to send. Because of the underlying hypercall in
+ *       hvc_put_chars(), this buffer must be at least 16 bytes long, even if
+ *       you are sending fewer chars.
+ * @count: number of chars to send.
+ */
 static int hvterm_raw_put_chars(uint32_t vtermno, const char *buf, int count)
 {
 	struct hvterm_priv *pv = hvterm_privs[vtermno];
@@ -219,6 +227,7 @@
 static void udbg_hvc_putc(char c)
 {
 	int count = -1;
+	unsigned char bounce_buffer[16];
 
 	if (!hvterm_privs[0])
 		return;
@@ -229,7 +238,12 @@
 	do {
 		switch(hvterm_privs[0]->proto) {
 		case HV_PROTOCOL_RAW:
-			count = hvterm_raw_put_chars(0, &c, 1);
+			/*
+			 * hvterm_raw_put_chars requires at least a 16-byte
+			 * buffer, so go via the bounce buffer
+			 */
+			bounce_buffer[0] = c;
+			count = hvterm_raw_put_chars(0, bounce_buffer, 1);
 			break;
 		case HV_PROTOCOL_HVSI:
 			count = hvterm_hvsi_put_chars(0, &c, 1);
@@ -371,20 +385,11 @@
 void __init hvc_vio_init_early(void)
 {
 	const __be32 *termno;
-	const char *name;
 	const struct hv_ops *ops;
 
 	/* find the boot console from /chosen/stdout */
-	if (!of_stdout)
-		return;
-	name = of_get_property(of_stdout, "name", NULL);
-	if (!name) {
-		printk(KERN_WARNING "stdout node missing 'name' property!\n");
-		return;
-	}
-
 	/* Check if it's a virtual terminal */
-	if (strncmp(name, "vty", 3) != 0)
+	if (!of_node_name_prefix(of_stdout, "vty"))
 		return;
 	termno = of_get_property(of_stdout, "reg", NULL);
 	if (termno == NULL)
diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c
index dc43fa9..5ef0890 100644
--- a/drivers/tty/hvc/hvc_xen.c
+++ b/drivers/tty/hvc/hvc_xen.c
@@ -492,7 +492,7 @@
 	case XenbusStateClosed:
 		if (dev->state == XenbusStateClosed)
 			break;
-		/* Missed the backend's CLOSING state -- fallthrough */
+		/* fall through - Missed the backend's CLOSING state. */
 	case XenbusStateClosing:
 		xenbus_frontend_closed(dev);
 		break;
diff --git a/drivers/tty/hvc/hvcs.c b/drivers/tty/hvc/hvcs.c
index cb4db1b..ee0604c 100644
--- a/drivers/tty/hvc/hvcs.c
+++ b/drivers/tty/hvc/hvcs.c
@@ -47,7 +47,7 @@
  * using the 2.6 Linux kernel kref construct.
  *
  * For direction on installation and usage of this driver please reference
- * Documentation/powerpc/hvcs.txt.
+ * Documentation/powerpc/hvcs.rst.
  */
 
 #include <linux/device.h>
@@ -871,8 +871,8 @@
 	hvcsd->p_partition_ID  = pi->partition_ID;
 
 	/* copy the null-term char too */
-	strlcpy(&hvcsd->p_location_code[0],
-			&pi->location_code[0], sizeof(hvcsd->p_location_code));
+	strlcpy(hvcsd->p_location_code, pi->location_code,
+		sizeof(hvcsd->p_location_code));
 }
 
 /*