1 files changed, 93 insertions, 0 deletions

diff --git a/arch/mn10300/kernel/gdb-io-ttysm-low.S b/arch/mn10300/kernel/gdb-io-ttysm-low.S
new file mode 100644
index 000000000000..677c7876307c
--- /dev/null
+++ b/arch/mn10300/kernel/gdb-io-ttysm-low.S
@@ -0,0 +1,93 @@
+###############################################################################
+#
+# MN10300 On-chip serial Rx interrupt handler for GDB stub I/O
+#
+# Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+# Written by David Howells (dhowells@redhat.com)
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public Licence
+# as published by the Free Software Foundation; either version
+# 2 of the Licence, or (at your option) any later version.
+#
+###############################################################################
+#include <linux/sys.h>
+#include <linux/linkage.h>
+#include <asm/smp.h>
+#include <asm/thread_info.h>
+#include <asm/cpu-regs.h>
+#include <asm/frame.inc>
+#include <asm/intctl-regs.h>
+#include <asm/unit/serial.h>
+#include "mn10300-serial.h"
+
+        .text
+
+###############################################################################
+#
+# GDB stub serial receive interrupt entry point
+# - intended to run at interrupt priority 0
+#
+###############################################################################
+        .globl  gdbstub_io_rx_handler
+        .type   gdbstub_io_rx_handler,@function
+gdbstub_io_rx_handler:
+        movm    [d2,d3,a2,a3],(sp)
+
+        mov     (gdbstub_rx_inp),a3
+gdbstub_io_rx_more:
+        mov     a3,a2
+        add     2,a3
+        and     PAGE_SIZE_asm-1,a3
+        mov     (gdbstub_rx_outp),d3
+        cmp     a3,d3
+        beq     gdbstub_io_rx_overflow
+
+        movbu   (SCgSTR),d3
+        btst    SC01STR_RBF,d3
+        beq     gdbstub_io_rx_done
+        movbu   (SCgRXB),d2
+        movbu   d3,(gdbstub_rx_buffer+1,a2)
+        movbu   d2,(gdbstub_rx_buffer,a2)
+        mov     a3,(gdbstub_rx_inp)
+        bra     gdbstub_io_rx_more
+
+gdbstub_io_rx_done:
+        mov     GxICR_DETECT,d2
+        movbu   d2,(GxICR(SCgRXIRQ))    # ACK the interrupt
+        movhu   (GxICR(SCgRXIRQ)),d2    # flush
+
+        movm    (sp),[d2,d3,a2,a3]
+        bset    0x01,(gdbstub_busy)
+        beq     gdbstub_io_rx_enter
+        rti
+
+gdbstub_io_rx_overflow:
+        bset    0x01,(gdbstub_rx_overflow)
+        bra     gdbstub_io_rx_done
+
+###############################################################################
+#
+# debugging interrupt - enter the GDB stub proper
+#
+###############################################################################
+gdbstub_io_rx_enter:
+        or      EPSW_IE|EPSW_IM_1,epsw
+        add     -4,sp
+        SAVE_ALL
+
+        mov     0xffffffff,d0
+        mov     d0,(REG_ORIG_D0,fp)
+        mov     0x280,d1
+
+        mov     fp,d0
+        call    gdbstub_rx_irq[],0      # gdbstub_io_rx_irq(regs,excep)
+
+        and     ~EPSW_IE,epsw
+        bclr    0x01,(gdbstub_busy)
+
+        .globl gdbstub_return
+gdbstub_return:
+        RESTORE_ALL
+
+        .size   gdbstub_io_rx_handler,.-gdbstub_io_rx_handler