powerpc: Simplify and clean up the xmon terminal I/O

This factors out the common bits of arch/powerpc/xmon/start_*.c into
a new nonstdio.c, and removes some stuff that was supposed to make
xmon's I/O routines somewhat stdio-like but was never used.

It also makes the parsing of the xmon= command line option common,
so that ppc32 can now use xmon={off,on,early} also.

Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/kernel/setup-common.c

@@ -51,6 +51,7 @@
 #include <asm/page.h>
 #include <asm/mmu.h>
 #include <asm/lmb.h>
+#include <asm/xmon.h>
 
 #undef DEBUG
 
@@ -559,3 +560,23 @@ void __init smp_setup_cpu_maps(void)
 #endif /* CONFIG_PPC64 */
 }
 #endif /* CONFIG_SMP */
+
+#ifdef CONFIG_XMON
+static int __init early_xmon(char *p)
+{
+	/* ensure xmon is enabled */
+	if (p) {
+		if (strncmp(p, "on", 2) == 0)
+			xmon_init(1);
+		if (strncmp(p, "off", 3) == 0)
+			xmon_init(0);
+		if (strncmp(p, "early", 5) != 0)
+			return 0;
+	}
+	xmon_init(1);
+	debugger(NULL);
+
+	return 0;
+}
+early_param("xmon", early_xmon);
+#endif

arch/powerpc/kernel/setup_32.c

@@ -303,14 +303,9 @@ void __init setup_arch(char **cmdline_p)
 		pmac_feature_init();	/* New cool way */
 #endif
 
-#ifdef CONFIG_XMON
-	xmon_map_scc();
-	if (strstr(cmd_line, "xmon")) {
-		xmon_init(1);
-		debugger(NULL);
-	}
-#endif /* CONFIG_XMON */
-	if ( ppc_md.progress ) ppc_md.progress("setup_arch: enter", 0x3eab);
+#ifdef CONFIG_XMON_DEFAULT
+	xmon_init(1);
+#endif
 
 #if defined(CONFIG_KGDB)
 	if (ppc_md.kgdb_map_scc)

arch/powerpc/kernel/setup_64.c

@@ -858,26 +858,6 @@ int check_legacy_ioport(unsigned long base_port)
 }
 EXPORT_SYMBOL(check_legacy_ioport);
 
-#ifdef CONFIG_XMON
-static int __init early_xmon(char *p)
-{
-	/* ensure xmon is enabled */
-	if (p) {
-		if (strncmp(p, "on", 2) == 0)
-			xmon_init(1);
-		if (strncmp(p, "off", 3) == 0)
-			xmon_init(0);
-		if (strncmp(p, "early", 5) != 0)
-			return 0;
-	}
-	xmon_init(1);
-	debugger(NULL);
-
-	return 0;
-}
-early_param("xmon", early_xmon);
-#endif
-
 void cpu_die(void)
 {
 	if (ppc_md.cpu_die)

arch/powerpc/xmon/Makefile

@@ -8,4 +8,4 @@ obj-$(CONFIG_8xx)	+= start_8xx.o
 obj-$(CONFIG_6xx)	+= start_32.o
 obj-$(CONFIG_4xx)	+= start_32.o
 obj-$(CONFIG_PPC64)	+= start_64.o
-obj-y			+= xmon.o ppc-dis.o ppc-opc.o subr_prf.o setjmp.o
+obj-y			+= xmon.o ppc-dis.o ppc-opc.o setjmp.o nonstdio.o

arch/powerpc/xmon/nonstdio.c

@@ -0,0 +1,134 @@
+/*
+ * Copyright (C) 1996-2005 Paul Mackerras.
+ *
+ *      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 <linux/string.h>
+#include <asm/time.h>
+#include "nonstdio.h"
+
+int xmon_putchar(int c)
+{
+	char ch = c;
+
+	if (c == '\n')
+		xmon_putchar('\r');
+	return xmon_write(&ch, 1) == 1? c: -1;
+}
+
+static char line[256];
+static char *lineptr;
+static int lineleft;
+
+int xmon_expect(const char *str, unsigned long timeout)
+{
+	int c;
+	unsigned long t0;
+
+	/* assume 25MHz default timebase if tb_ticks_per_sec not set yet */
+	timeout *= tb_ticks_per_sec? tb_ticks_per_sec: 25000000;
+	t0 = get_tbl();
+	do {
+		lineptr = line;
+		for (;;) {
+			c = xmon_read_poll();
+			if (c == -1) {
+				if (get_tbl() - t0 > timeout)
+					return 0;
+				continue;
+			}
+			if (c == '\n')
+				break;
+			if (c != '\r' && lineptr < &line[sizeof(line) - 1])
+				*lineptr++ = c;
+		}
+		*lineptr = 0;
+	} while (strstr(line, str) == NULL);
+	return 1;
+}
+
+int xmon_getchar(void)
+{
+	int c;
+
+	if (lineleft == 0) {
+		lineptr = line;
+		for (;;) {
+			c = xmon_readchar();
+			if (c == -1 || c == 4)
+				break;
+			if (c == '\r' || c == '\n') {
+				*lineptr++ = '\n';
+				xmon_putchar('\n');
+				break;
+			}
+			switch (c) {
+			case 0177:
+			case '\b':
+				if (lineptr > line) {
+					xmon_putchar('\b');
+					xmon_putchar(' ');
+					xmon_putchar('\b');
+					--lineptr;
+				}
+				break;
+			case 'U' & 0x1F:
+				while (lineptr > line) {
+					xmon_putchar('\b');
+					xmon_putchar(' ');
+					xmon_putchar('\b');
+					--lineptr;
+				}
+				break;
+			default:
+				if (lineptr >= &line[sizeof(line) - 1])
+					xmon_putchar('\a');
+				else {
+					xmon_putchar(c);
+					*lineptr++ = c;
+				}
+			}
+		}
+		lineleft = lineptr - line;
+		lineptr = line;
+	}
+	if (lineleft == 0)
+		return -1;
+	--lineleft;
+	return *lineptr++;
+}
+
+char *xmon_gets(char *str, int nb)
+{
+	char *p;
+	int c;
+
+	for (p = str; p < str + nb - 1; ) {
+		c = xmon_getchar();
+		if (c == -1) {
+			if (p == str)
+				return NULL;
+			break;
+		}
+		*p++ = c;
+		if (c == '\n')
+			break;
+	}
+	*p = 0;
+	return str;
+}
+
+void xmon_printf(const char *format, ...)
+{
+	va_list args;
+	int n;
+	static char xmon_outbuf[1024];
+
+	va_start(args, format);
+	n = vsnprintf(xmon_outbuf, sizeof(xmon_outbuf), format, args);
+	va_end(args);
+	xmon_write(xmon_outbuf, n);
+}

arch/powerpc/xmon/nonstdio.h

@@ -1,22 +1,14 @@
-typedef int	FILE;
-extern FILE *xmon_stdin, *xmon_stdout;
 #define EOF	(-1)
-#define stdin	xmon_stdin
-#define stdout	xmon_stdout
+
 #define printf	xmon_printf
-#define fprintf	xmon_fprintf
-#define fputs	xmon_fputs
-#define fgets	xmon_fgets
 #define putchar	xmon_putchar
-#define getchar	xmon_getchar
-#define putc	xmon_putc
-#define getc	xmon_getc
-#define fopen(n, m)	NULL
-#define fflush(f)	do {} while (0)
-#define fclose(f)	do {} while (0)
-extern char *fgets(char *, int, void *);
-extern void xmon_printf(const char *, ...);
-extern void xmon_fprintf(void *, const char *, ...);
-extern void xmon_sprintf(char *, const char *, ...);
 
-#define perror(s)	printf("%s: no files!\n", (s))
+extern int xmon_putchar(int c);
+extern int xmon_getchar(void);
+extern char *xmon_gets(char *, int);
+extern void xmon_printf(const char *, ...);
+extern void xmon_map_scc(void);
+extern int xmon_expect(const char *str, unsigned long timeout);
+extern int xmon_write(void *ptr, int nb);
+extern int xmon_readchar(void);
+extern int xmon_read_poll(void);