1 files changed, 70 insertions, 0 deletions
diff --git a/arch/sparc/prom/printf.c b/arch/sparc/prom/printf.c
new file mode 100644
index 0000000000..dcee3dfa6d
--- /dev/null
+++ b/arch/sparc/prom/printf.c
@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * printf.c:  Internal prom library printf facility.
+ *
+ * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
+ * Copyright (C) 1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
+ * Copyright (c) 2002 Pete Zaitcev (zaitcev@yahoo.com)
+ *
+ * We used to warn all over the code: DO NOT USE prom_printf(),
+ * and yet people do. Anton's banking code was outputting banks
+ * with prom_printf for most of the 2.4 lifetime. Since an effective
+ * stick is not available, we deployed a carrot: an early printk
+ * through PROM by means of -p boot option. This ought to fix it.
+ * USE printk; if you need, deploy -p.
+ */
+
+#include <linux/kernel.h>
+#include <linux/compiler.h>
+#include <linux/spinlock.h>
+
+#include <asm/openprom.h>
+#include <asm/oplib.h>
+
+#define CONSOLE_WRITE_BUF_SIZE	1024
+
+static char ppbuf[1024];
+static char console_write_buf[CONSOLE_WRITE_BUF_SIZE];
+static DEFINE_RAW_SPINLOCK(console_write_lock);
+
+void notrace prom_write(const char *buf, unsigned int n)
+{
+	unsigned int dest_len;
+	unsigned long flags;
+	char *dest;
+
+	dest = console_write_buf;
+	raw_spin_lock_irqsave(&console_write_lock, flags);
+
+	dest_len = 0;
+	while (n-- != 0) {
+		char ch = *buf++;
+		if (ch == '\n') {
+			*dest++ = '\r';
+			dest_len++;
+		}
+		*dest++ = ch;
+		dest_len++;
+		if (dest_len >= CONSOLE_WRITE_BUF_SIZE - 1) {
+			prom_console_write_buf(console_write_buf, dest_len);
+			dest = console_write_buf;
+			dest_len = 0;
+		}
+	}
+	if (dest_len)
+		prom_console_write_buf(console_write_buf, dest_len);
+
+	raw_spin_unlock_irqrestore(&console_write_lock, flags);
+}
+
+void notrace prom_printf(const char *fmt, ...)
+{
+	va_list args;
+	int i;
+
+	va_start(args, fmt);
+	i = vscnprintf(ppbuf, sizeof(ppbuf), fmt, args);
+	va_end(args);
+
+	prom_write(ppbuf, i);
+}