---

yaml
---
r: 367239
b: refs/heads/master
c: e53f2f4
h: refs/heads/master
i:
  367237: 72c6c5c
  367235: 706ea13
  367231: 1ead25a
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 0492f72508184d451101564e235b0c32edf9acd3
+refs/heads/master: e53f2f4b570d85c7208dfc97de54db1296b88207

trunk/arch/arm64/kernel/early_printk.c

@@ -24,6 +24,7 @@
 #include <linux/io.h>
 
 #include <linux/amba/serial.h>
+#include <linux/serial_reg.h>
 
 static void __iomem *early_base;
 static void (*printch)(char ch);
@@ -51,6 +52,26 @@ static void smh_printch(char ch)
 		     : : "r" (&ch) : "x0", "x1", "memory");
 }
 
+/*
+ * 8250/16550 (8-bit aligned registers) single character TX.
+ */
+static void uart8250_8bit_printch(char ch)
+{
+	while (!(readb_relaxed(early_base + UART_LSR) & UART_LSR_THRE))
+		;
+	writeb_relaxed(ch, early_base + UART_TX);
+}
+
+/*
+ * 8250/16550 (32-bit aligned registers) single character TX.
+ */
+static void uart8250_32bit_printch(char ch)
+{
+	while (!(readl_relaxed(early_base + (UART_LSR << 2)) & UART_LSR_THRE))
+		;
+	writel_relaxed(ch, early_base + (UART_TX << 2));
+}
+
 struct earlycon_match {
 	const char *name;
 	void (*printch)(char ch);
@@ -59,6 +80,8 @@ struct earlycon_match {
 static const struct earlycon_match earlycon_match[] __initconst = {
 	{ .name = "pl011", .printch = pl011_printch, },
 	{ .name = "smh", .printch = smh_printch, },
+	{ .name = "uart8250-8bit", .printch = uart8250_8bit_printch, },
+	{ .name = "uart8250-32bit", .printch = uart8250_32bit_printch, },
 	{}
 };