[PATCH] powerpc: Move udbg code to arch/powerpc

Since the udbg code in ppc64 has no ppc32 equivalent, move it straight
over into arch/powerpc (and include/asm-powerpc for udbg.h).  In time,
we probably want to meld the various bits and pieces of 32-bit early
debugging code into udbg, but for now only include it on
CONFIG_PPC64=y builds.  The only change during the move is to
standardise the protecting #ifdef/#define in udbg.h, and move its
banner comment above the initial #ifdef (which seems to be normal
practice).

Built and booted on POWER5 LPAR (ARCH=powerpc and ARCH=ppc64).  Built
for 32bit multiplatform (ARCH=powerpc).

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/kernel/udbg.c

@@ -0,0 +1,125 @@
+/*
+ * polling mode stateless debugging stuff, originally for NS16550 Serial Ports
+ *
+ * c 2001 PPC 64 Team, IBM Corp
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+
+#include <stdarg.h>
+#include <linux/config.h>
+#include <linux/types.h>
+#include <linux/sched.h>
+#include <linux/console.h>
+#include <asm/processor.h>
+
+void (*udbg_putc)(unsigned char c);
+unsigned char (*udbg_getc)(void);
+int (*udbg_getc_poll)(void);
+
+/* udbg library, used by xmon et al */
+void udbg_puts(const char *s)
+{
+	if (udbg_putc) {
+		char c;
+
+		if (s && *s != '\0') {
+			while ((c = *s++) != '\0')
+				udbg_putc(c);
+		}
+	}
+#if 0
+	else {
+		printk("%s", s);
+	}
+#endif
+}
+
+int udbg_write(const char *s, int n)
+{
+	int remain = n;
+	char c;
+
+	if (!udbg_putc)
+		return 0;
+
+	if (s && *s != '\0') {
+		while (((c = *s++) != '\0') && (remain-- > 0)) {
+			udbg_putc(c);
+		}
+	}
+
+	return n - remain;
+}
+
+int udbg_read(char *buf, int buflen)
+{
+	char c, *p = buf;
+	int i;
+
+	if (!udbg_getc)
+		return 0;
+
+	for (i = 0; i < buflen; ++i) {
+		do {
+			c = udbg_getc();
+		} while (c == 0x11 || c == 0x13);
+		if (c == 0)
+			break;
+		*p++ = c;
+	}
+
+	return i;
+}
+
+#define UDBG_BUFSIZE 256
+void udbg_printf(const char *fmt, ...)
+{
+	unsigned char buf[UDBG_BUFSIZE];
+	va_list args;
+
+	va_start(args, fmt);
+	vsnprintf(buf, UDBG_BUFSIZE, fmt, args);
+	udbg_puts(buf);
+	va_end(args);
+}
+
+/*
+ * Early boot console based on udbg
+ */
+static void udbg_console_write(struct console *con, const char *s,
+		unsigned int n)
+{
+	udbg_write(s, n);
+}
+
+static struct console udbg_console = {
+	.name	= "udbg",
+	.write	= udbg_console_write,
+	.flags	= CON_PRINTBUFFER,
+	.index	= -1,
+};
+
+static int early_console_initialized;
+
+void __init disable_early_printk(void)
+{
+	if (!early_console_initialized)
+		return;
+	unregister_console(&udbg_console);
+	early_console_initialized = 0;
+}
+
+/* called by setup_system */
+void register_early_udbg_console(void)
+{
+	early_console_initialized = 1;
+	register_console(&udbg_console);
+}
+
+#if 0   /* if you want to use this as a regular output console */
+console_initcall(register_udbg_console);
+#endif