004b50f4ed
Introduce into the MN10300 gdbstub 16550 driver a couple of barrier() calls to replace the removed volatility of the input/output index variables for the Rx ring buffer. A previous patch added them into the on-chip serial port driver. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
158 lines
3.3 KiB
C
158 lines
3.3 KiB
C
/* 16550 serial driver for gdbstub I/O
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*
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* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public Licence
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* as published by the Free Software Foundation; either version
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* 2 of the Licence, or (at your option) any later version.
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*/
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#include <linux/string.h>
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#include <linux/kernel.h>
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#include <linux/signal.h>
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#include <linux/sched.h>
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#include <linux/mm.h>
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#include <linux/console.h>
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#include <linux/init.h>
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#include <linux/nmi.h>
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#include <asm/pgtable.h>
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#include <asm/system.h>
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#include <asm/gdb-stub.h>
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#include <asm/exceptions.h>
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#include <asm/serial-regs.h>
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#include <asm/unit/serial.h>
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/*
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* initialise the GDB stub
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*/
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void gdbstub_io_init(void)
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{
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u16 tmp;
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/* set up the serial port */
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GDBPORT_SERIAL_LCR = UART_LCR_WLEN8; /* 1N8 */
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GDBPORT_SERIAL_FCR = (UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR |
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UART_FCR_CLEAR_XMIT);
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FLOWCTL_CLEAR(DTR);
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FLOWCTL_SET(RTS);
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gdbstub_io_set_baud(115200);
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/* we want to get serial receive interrupts */
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XIRQxICR(GDBPORT_SERIAL_IRQ) = 0;
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tmp = XIRQxICR(GDBPORT_SERIAL_IRQ);
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IVAR0 = EXCEP_IRQ_LEVEL0;
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set_intr_stub(EXCEP_IRQ_LEVEL0, gdbstub_io_rx_handler);
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XIRQxICR(GDBPORT_SERIAL_IRQ) &= ~GxICR_REQUEST;
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XIRQxICR(GDBPORT_SERIAL_IRQ) = GxICR_ENABLE | GxICR_LEVEL_0;
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tmp = XIRQxICR(GDBPORT_SERIAL_IRQ);
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GDBPORT_SERIAL_IER = UART_IER_RDI | UART_IER_RLSI;
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/* permit level 0 IRQs to take place */
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asm volatile(
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" and %0,epsw \n"
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" or %1,epsw \n"
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:
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: "i"(~EPSW_IM), "i"(EPSW_IE | EPSW_IM_1)
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);
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}
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/*
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* set up the GDB stub serial port baud rate timers
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*/
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void gdbstub_io_set_baud(unsigned baud)
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{
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unsigned value;
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u8 lcr;
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value = 18432000 / 16 / baud;
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lcr = GDBPORT_SERIAL_LCR;
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GDBPORT_SERIAL_LCR |= UART_LCR_DLAB;
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GDBPORT_SERIAL_DLL = value & 0xff;
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GDBPORT_SERIAL_DLM = (value >> 8) & 0xff;
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GDBPORT_SERIAL_LCR = lcr;
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}
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/*
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* wait for a character to come from the debugger
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*/
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int gdbstub_io_rx_char(unsigned char *_ch, int nonblock)
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{
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unsigned ix;
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u8 ch, st;
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*_ch = 0xff;
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if (gdbstub_rx_unget) {
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*_ch = gdbstub_rx_unget;
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gdbstub_rx_unget = 0;
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return 0;
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}
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try_again:
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/* pull chars out of the buffer */
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ix = gdbstub_rx_outp;
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barrier();
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if (ix == gdbstub_rx_inp) {
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if (nonblock)
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return -EAGAIN;
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#ifdef CONFIG_MN10300_WD_TIMER
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watchdog_alert_counter = 0;
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#endif /* CONFIG_MN10300_WD_TIMER */
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goto try_again;
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}
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ch = gdbstub_rx_buffer[ix++];
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st = gdbstub_rx_buffer[ix++];
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barrier();
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gdbstub_rx_outp = ix & 0x00000fff;
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if (st & UART_LSR_BI) {
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gdbstub_proto("### GDB Rx Break Detected ###\n");
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return -EINTR;
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} else if (st & (UART_LSR_FE | UART_LSR_OE | UART_LSR_PE)) {
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gdbstub_proto("### GDB Rx Error (st=%02x) ###\n", st);
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return -EIO;
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} else {
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gdbstub_proto("### GDB Rx %02x (st=%02x) ###\n", ch, st);
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*_ch = ch & 0x7f;
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return 0;
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}
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}
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/*
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* send a character to the debugger
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*/
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void gdbstub_io_tx_char(unsigned char ch)
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{
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FLOWCTL_SET(DTR);
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LSR_WAIT_FOR(THRE);
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/* FLOWCTL_WAIT_FOR(CTS); */
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if (ch == 0x0a) {
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GDBPORT_SERIAL_TX = 0x0d;
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LSR_WAIT_FOR(THRE);
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/* FLOWCTL_WAIT_FOR(CTS); */
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}
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GDBPORT_SERIAL_TX = ch;
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FLOWCTL_CLEAR(DTR);
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}
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/*
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* send a character to the debugger
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*/
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void gdbstub_io_tx_flush(void)
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{
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LSR_WAIT_FOR(TEMT);
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LSR_WAIT_FOR(THRE);
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FLOWCTL_CLEAR(DTR);
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}
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