LXR linux/arch/mn10300/kernel/gdb-io-ttysm-low.S

   1###############################################################################
   2#
   3# MN10300 On-chip serial Rx interrupt handler for GDB stub I/O
   4#
   5# Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   6# Written by David Howells (dhowells@redhat.com)
   7#
   8# This program is free software; you can redistribute it and/or
   9# modify it under the terms of the GNU General Public Licence
  10# as published by the Free Software Foundation; either version
  11# 2 of the Licence, or (at your option) any later version.
  12#
  13###############################################################################
  14#include <linux/sys.h>
  15#include <linux/linkage.h>
  16#include <asm/smp.h>
  17#include <asm/thread_info.h>
  18#include <asm/cpu-regs.h>
  19#include <asm/frame.inc>
  20#include <asm/intctl-regs.h>
  21#include <unit/serial.h>
  22#include "mn10300-serial.h"
  23
  24        .text
  25
  26###############################################################################
  27#
  28# GDB stub serial receive interrupt entry point
  29# - intended to run at interrupt priority 0
  30#
  31###############################################################################
  32        .globl  gdbstub_io_rx_handler
  33        .type   gdbstub_io_rx_handler,@function
  34gdbstub_io_rx_handler:
  35        movm    [d2,d3,a2,a3],(sp)
  36
  37        mov     (gdbstub_rx_inp),a3
  38gdbstub_io_rx_more:
  39        mov     a3,a2
  40        add     2,a3
  41        and     PAGE_SIZE_asm-1,a3
  42        mov     (gdbstub_rx_outp),d3
  43        cmp     a3,d3
  44        beq     gdbstub_io_rx_overflow
  45
  46        movbu   (SCgSTR),d3
  47        btst    SC01STR_RBF,d3
  48        beq     gdbstub_io_rx_done
  49        movbu   (SCgRXB),d2
  50        movbu   d3,(gdbstub_rx_buffer+1,a2)
  51        movbu   d2,(gdbstub_rx_buffer,a2)
  52        mov     a3,(gdbstub_rx_inp)
  53        bra     gdbstub_io_rx_more
  54
  55gdbstub_io_rx_done:
  56        mov     GxICR_DETECT,d2
  57        movbu   d2,(GxICR(SCgRXIRQ))    # ACK the interrupt
  58        movhu   (GxICR(SCgRXIRQ)),d2    # flush
  59
  60        movm    (sp),[d2,d3,a2,a3]
  61        bset    0x01,(gdbstub_busy)
  62        beq     gdbstub_io_rx_enter
  63        rti
  64
  65gdbstub_io_rx_overflow:
  66        bset    0x01,(gdbstub_rx_overflow)
  67        bra     gdbstub_io_rx_done
  68
  69###############################################################################
  70#
  71# debugging interrupt - enter the GDB stub proper
  72#
  73###############################################################################
  74gdbstub_io_rx_enter:
  75        or      EPSW_IE|EPSW_IM_1,epsw
  76        add     -4,sp
  77        SAVE_ALL
  78
  79        mov     0xffffffff,d0
  80        mov     d0,(REG_ORIG_D0,fp)
  81        mov     0x280,d1
  82
  83        mov     fp,d0
  84        call    gdbstub_rx_irq[],0      # gdbstub_io_rx_irq(regs,excep)
  85
  86        and     ~EPSW_IE,epsw
  87        bclr    0x01,(gdbstub_busy)
  88
  89        .globl gdbstub_return
  90gdbstub_return:
  91        RESTORE_ALL
  92
  93        .size   gdbstub_io_rx_handler,.-gdbstub_io_rx_handler
  94