sparc: Pass buffer pointer all the way down to prom_{get,put}char().

This gets us closer to being able to eliminate the use
of dynamic and stack based buffers, so that we can adhere
to the "no buffer addresses above 4GB" rule for PROM calls.

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/arch/sparc/prom/console_64.c b/arch/sparc/prom/console_64.c
index 33a8b27..a9a5754 100644
--- a/arch/sparc/prom/console_64.c
+++ b/arch/sparc/prom/console_64.c
@@ -18,41 +18,37 @@
 /* Non blocking get character from console input device, returns -1
  * if no input was taken.  This can be used for polling.
  */
-static int prom_nbgetchar(void)
+static int prom_nbgetchar(char *buf)
 {
 	unsigned long args[7];
-	char inc;
 
 	args[0] = (unsigned long) "read";
 	args[1] = 3;
 	args[2] = 1;
 	args[3] = (unsigned int) prom_stdin;
-	args[4] = (unsigned long) &inc;
+	args[4] = (unsigned long) buf;
 	args[5] = 1;
 	args[6] = (unsigned long) -1;
 
 	p1275_cmd_direct(args);
 
 	if (args[6] == 1)
-		return inc;
+		return 0;
 	return -1;
 }
 
 /* Non blocking put character to console device, returns -1 if
  * unsuccessful.
  */
-static int prom_nbputchar(char c)
+static int prom_nbputchar(const char *buf)
 {
 	unsigned long args[7];
-	char outc;
-	
-	outc = c;
 
 	args[0] = (unsigned long) "write";
 	args[1] = 3;
 	args[2] = 1;
 	args[3] = (unsigned int) prom_stdout;
-	args[4] = (unsigned long) &outc;
+	args[4] = (unsigned long) buf;
 	args[5] = 1;
 	args[6] = (unsigned long) -1;
 
@@ -65,17 +61,21 @@
 }
 
 /* Blocking version of get character routine above. */
-char
-prom_getchar(void)
+void prom_getchar(char *buf)
 {
-	int character;
-	while((character = prom_nbgetchar()) == -1) ;
-	return (char) character;
+	while (1) {
+		int err = prom_nbgetchar(buf);
+		if (!err)
+			break;
+	}
 }
 
 /* Blocking version of put character routine above. */
-void
-prom_putchar(char c)
+void prom_putchar(const char *buf)
 {
-	prom_nbputchar(c);
+	while (1) {
+		int err = prom_nbputchar(buf);
+		if (!err)
+			break;
+	}
 }