powerpc: Merge xmon

The merged version follows the ppc64 version pretty closely mostly,
and in fact ARCH=ppc64 now uses the arch/powerpc/xmon version.
The main difference for ppc64 is that the 'p' command to call
show_state (which was always pretty dodgy) has been replaced by
the ppc32 'p' command, which calls a given procedure (so in fact
the old 'p' command behaviour can be achieved with 'p $show_state').

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

1 files changed, 187 insertions, 0 deletions

diff --git a/arch/powerpc/xmon/start_64.c b/arch/powerpc/xmon/start_64.c
new file mode 100644
index 000000000000..e50c158191e1
--- /dev/null
+++ b/arch/powerpc/xmon/start_64.c
@@ -0,0 +1,187 @@
+/*
+ * Copyright (C) 1996 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/config.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/sysrq.h>
+#include <linux/init.h>
+#include <asm/machdep.h>
+#include <asm/io.h>
+#include <asm/page.h>
+#include <asm/prom.h>
+#include <asm/processor.h>
+#include <asm/udbg.h>
+#include <asm/system.h>
+#include "nonstdio.h"
+
+#ifdef CONFIG_MAGIC_SYSRQ
+
+static void sysrq_handle_xmon(int key, struct pt_regs *pt_regs,
+			      struct tty_struct *tty) 
+{
+	/* ensure xmon is enabled */
+	xmon_init(1);
+	debugger(pt_regs);
+}
+
+static struct sysrq_key_op sysrq_xmon_op = 
+{
+	.handler =	sysrq_handle_xmon,
+	.help_msg =	"Xmon",
+	.action_msg =	"Entering xmon",
+};
+
+static int __init setup_xmon_sysrq(void)
+{
+	register_sysrq_key('x', &sysrq_xmon_op);
+	return 0;
+}
+__initcall(setup_xmon_sysrq);
+#endif /* CONFIG_MAGIC_SYSRQ */
+
+int
+xmon_write(void *handle, void *ptr, int nb)
+{
+	return udbg_write(ptr, nb);
+}
+
+int
+xmon_read(void *handle, void *ptr, int nb)
+{
+	return udbg_read(ptr, nb);
+}
+
+int
+xmon_read_poll(void)
+{
+	if (udbg_getc_poll)
+		return udbg_getc_poll();
+	return -1;
+}
+ 
+FILE *xmon_stdin;
+FILE *xmon_stdout;
+
+int
+xmon_putc(int c, void *f)
+{
+	char ch = c;
+
+	if (c == '\n')
+		xmon_putc('\r', f);
+	return xmon_write(f, &ch, 1) == 1? c: -1;
+}
+
+int
+xmon_putchar(int c)
+{
+	return xmon_putc(c, xmon_stdout);
+}
+
+int
+xmon_fputs(char *str, void *f)
+{
+	int n = strlen(str);
+
+	return xmon_write(f, str, n) == n? 0: -1;
+}
+
+int
+xmon_readchar(void)
+{
+	char ch;
+
+	for (;;) {
+		switch (xmon_read(xmon_stdin, &ch, 1)) {
+		case 1:
+			return ch;
+		case -1:
+			xmon_printf("read(stdin) returned -1\r\n", 0, 0);
+			return -1;
+		}
+	}
+}
+
+static char line[256];
+static char *lineptr;
+static int lineleft;
+
+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_fgets(char *str, int nb, void *f)
+{
+	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;
+}