arch/mn10300/kernel/gdb-io-serial-low.S

   1 ###############################################################################
   2 #
   3 # 16550 serial Rx interrupt handler for gdbstub 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/cpu-regs.h>
  18 #include <asm/thread_info.h>
  19 #include <asm/frame.inc>
  20 #include <asm/intctl-regs.h>
  21 #include <asm/unit/serial.h>
  22
  23         .text
  24
  25 ###############################################################################
  26 #
  27 # GDB stub serial receive interrupt entry point
  28 # - intended to run at interrupt priority 0
  29 #
  30 ###############################################################################
  31         .globl  gdbstub_io_rx_handler
  32         .type   gdbstub_io_rx_handler,@function
  33 gdbstub_io_rx_handler:
  34         movm    [d2,d3,a2,a3],(sp)
  35
  36 #if 1
  37         movbu   (GDBPORT_SERIAL_IIR),d2
  38 #endif
  39
  40         mov     (gdbstub_rx_inp),a3
  41 gdbstub_io_rx_more:
  42         mov     a3,a2
  43         add     2,a3
  44         and     0x00000fff,a3
  45         mov     (gdbstub_rx_outp),d3
  46         cmp     a3,d3
  47         beq     gdbstub_io_rx_overflow
  48
  49         movbu   (GDBPORT_SERIAL_LSR),d3
  50         btst    UART_LSR_DR,d3
  51         beq     gdbstub_io_rx_done
  52         movbu   (GDBPORT_SERIAL_RX),d2
  53         movbu   d3,(gdbstub_rx_buffer+1,a2)
  54         movbu   d2,(gdbstub_rx_buffer,a2)
  55         mov     a3,(gdbstub_rx_inp)
  56         bra     gdbstub_io_rx_more
  57
  58 gdbstub_io_rx_done:
  59         mov     GxICR_DETECT,d2
  60         movbu   d2,(XIRQxICR(GDBPORT_SERIAL_IRQ))       # ACK the interrupt
  61         movhu   (XIRQxICR(GDBPORT_SERIAL_IRQ)),d2       # flush
  62         movm    (sp),[d2,d3,a2,a3]
  63         bset    0x01,(gdbstub_busy)
  64         beq     gdbstub_io_rx_enter
  65         rti
  66
  67 gdbstub_io_rx_overflow:
  68         bset    0x01,(gdbstub_rx_overflow)
  69         bra     gdbstub_io_rx_done
  70
  71 gdbstub_io_rx_enter:
  72         or      EPSW_IE|EPSW_IM_1,epsw
  73         add     -4,sp
  74         SAVE_ALL
  75
  76         mov     0xffffffff,d0
  77         mov     d0,(REG_ORIG_D0,fp)
  78         mov     0x280,d1
  79
  80         mov     fp,d0
  81         call    gdbstub_rx_irq[],0      # gdbstub_rx_irq(regs,excep)
  82
  83         and     ~EPSW_IE,epsw
  84         bclr    0x01,(gdbstub_busy)
  85
  86         .globl gdbstub_return
  87 gdbstub_return:
  88         RESTORE_ALL
  89
  90         .size   gdbstub_io_rx_handler,.-gdbstub_io_rx_handler