sparc64: Implement IRQ stacks.

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/arch/sparc64/kernel/kstack.h b/arch/sparc64/kernel/kstack.h
new file mode 100644
index 0000000..43909d5
--- /dev/null
+++ b/arch/sparc64/kernel/kstack.h
@@ -0,0 +1,58 @@
+#ifndef _KSTACK_H
+#define _KSTACK_H
+
+#include <linux/thread_info.h>
+#include <linux/sched.h>
+#include <asm/ptrace.h>
+#include <asm/irq.h>
+
+/* SP must be STACK_BIAS adjusted already.  */
+static inline bool kstack_valid(struct thread_info *tp, unsigned long sp)
+{
+	unsigned long base = (unsigned long) tp;
+
+	if (sp >= (base + sizeof(struct thread_info)) &&
+	    sp <= (base + THREAD_SIZE - sizeof(struct sparc_stackf)))
+		return true;
+
+	base = (unsigned long) hardirq_stack[tp->cpu];
+	if (sp >= base &&
+	    sp <= (base + THREAD_SIZE - sizeof(struct sparc_stackf)))
+		return true;
+	base = (unsigned long) softirq_stack[tp->cpu];
+	if (sp >= base &&
+	    sp <= (base + THREAD_SIZE - sizeof(struct sparc_stackf)))
+		return true;
+
+	return false;
+}
+
+/* Does "regs" point to a valid pt_regs trap frame?  */
+static inline bool kstack_is_trap_frame(struct thread_info *tp, struct pt_regs *regs)
+{
+	unsigned long base = (unsigned long) tp;
+	unsigned long addr = (unsigned long) regs;
+
+	if (addr >= base &&
+	    addr <= (base + THREAD_SIZE - sizeof(*regs)))
+		goto check_magic;
+
+	base = (unsigned long) hardirq_stack[tp->cpu];
+	if (addr >= base &&
+	    addr <= (base + THREAD_SIZE - sizeof(*regs)))
+		goto check_magic;
+	base = (unsigned long) softirq_stack[tp->cpu];
+	if (addr >= base &&
+	    addr <= (base + THREAD_SIZE - sizeof(*regs)))
+		goto check_magic;
+
+	return false;
+
+check_magic:
+	if ((regs->magic & ~0x1ff) == PT_REGS_MAGIC)
+		return true;
+	return false;
+
+}
+
+#endif /* _KSTACK_H */