microblaze_v8: traps support

Reviewed-by: NIngo Molnar <mingo@elte.hu>
Acked-by: NJohn Linn <john.linn@xilinx.com>
Acked-by: NStephen Neuendorffer <stephen.neuendorffer@xilinx.com>
Acked-by: NJohn Williams <john.williams@petalogix.com>
Signed-off-by: NMichal Simek <monstr@monstr.eu>

arch/microblaze/kernel/traps.c

+/*
+ * Copyright (C) 2007-2009 Michal Simek <monstr@monstr.eu>
+ * Copyright (C) 2007-2009 PetaLogix
+ * Copyright (C) 2006 Atmark Techno, Inc.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/kallsyms.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/debug_locks.h>
+
+#include <asm/exceptions.h>
+#include <asm/system.h>
+
+void trap_init(void)
+{
+	__enable_hw_exceptions();
+}
+
+void __bad_xchg(volatile void *ptr, int size)
+{
+	printk(KERN_INFO "xchg: bad data size: pc 0x%p, ptr 0x%p, size %d\n",
+		__builtin_return_address(0), ptr, size);
+	BUG();
+}
+EXPORT_SYMBOL(__bad_xchg);
+
+static int kstack_depth_to_print = 24;
+
+static int __init kstack_setup(char *s)
+{
+	kstack_depth_to_print = strict_strtoul(s, 0, 0);
+
+	return 1;
+}
+__setup("kstack=", kstack_setup);
+
+void show_trace(struct task_struct *task, unsigned long *stack)
+{
+	unsigned long addr;
+
+	if (!stack)
+		stack = (unsigned long *)&stack;
+
+	printk(KERN_NOTICE "Call Trace: ");
+#ifdef CONFIG_KALLSYMS
+	printk(KERN_NOTICE "\n");
+#endif
+	while (!kstack_end(stack)) {
+		addr = *stack++;
+		/*
+		 * If the address is either in the text segment of the
+		 * kernel, or in the region which contains vmalloc'ed
+		 * memory, it *may* be the address of a calling
+		 * routine; if so, print it so that someone tracing
+		 * down the cause of the crash will be able to figure
+		 * out the call path that was taken.
+		 */
+		if (kernel_text_address(addr))
+			print_ip_sym(addr);
+	}
+	printk(KERN_NOTICE "\n");
+
+	if (!task)
+		task = current;
+
+	debug_show_held_locks(task);
+}
+
+void show_stack(struct task_struct *task, unsigned long *sp)
+{
+	unsigned long *stack;
+	int i;
+
+	if (sp == NULL) {
+		if (task)
+			sp = (unsigned long *) ((struct thread_info *)
+						(task->stack))->cpu_context.r1;
+		else
+			sp = (unsigned long *)&sp;
+	}
+
+	stack = sp;
+
+	printk(KERN_INFO "\nStack:\n  ");
+
+	for (i = 0; i < kstack_depth_to_print; i++) {
+		if (kstack_end(sp))
+			break;
+		if (i && ((i % 8) == 0))
+			printk("\n  ");
+		printk("%08lx ", *sp++);
+	}
+	printk("\n");
+	show_trace(task, stack);
+}
+
+void dump_stack(void)
+{
+	show_stack(NULL, NULL);
+}
+EXPORT_SYMBOL(dump_stack);