sys/arch/sun2/dev/zs_kgdb.c

   1 /*      $NetBSD: zs_kgdb.c,v 1.9 2007/10/17 19:57:43 garbled Exp $      */
   2
   3 /*-
   4  * Copyright (c) 1996 The NetBSD Foundation, Inc.
   5  * All rights reserved.
   6  *
   7  * This code is derived from software contributed to The NetBSD Foundation
   8  * by Gordon W. Ross.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  29  * POSSIBILITY OF SUCH DAMAGE.
  30  */
  31
  32 /*
  33  * Hooks for kgdb when attached via the z8530 driver
  34  *
  35  * To use this, build a kernel with: option KGDB, and
  36  * boot that kernel with "-d".  (The kernel will call
  37  * zs_kgdb_init, kgdb_connect.)  When the console prints
  38  * "kgdb waiting..." you run "gdb -k kernel" and do:
  39  *   (gdb) set remotebaud 19200
  40  *   (gdb) target remote /dev/ttyb
  41  */
  42
  43 #include <sys/cdefs.h>
  44 __KERNEL_RCSID(0, "$NetBSD: zs_kgdb.c,v 1.9 2007/10/17 19:57:43 garbled Exp $");
  45
  46 #include "opt_kgdb.h"
  47
  48 #include <sys/param.h>
  49 #include <sys/systm.h>
  50 #include <sys/proc.h>
  51 #include <sys/device.h>
  52 #include <sys/conf.h>
  53 #include <sys/ioctl.h>
  54 #include <sys/kernel.h>
  55 #include <sys/syslog.h>
  56 #include <sys/kgdb.h>
  57
  58 #include <dev/ic/z8530reg.h>
  59 #include <machine/z8530var.h>
  60 #include <machine/promlib.h>
  61 #include <sun2/dev/cons.h>
  62
  63 static void zs_setparam(struct zs_chanstate *, int, int);
  64 struct zsops zsops_kgdb;
  65
  66 extern int  zs_getc(void *arg);
  67 extern void zs_putc(void *arg, int c);
  68
  69 static u_char zs_kgdb_regs[16] = {
  70         0,      /* 0: CMD (reset, etc.) */
  71         0,      /* 1: No interrupts yet. */
  72 #ifdef  ZS_INIT_IVECT
  73         ZS_INIT_IVECT,  /* 2: IVECT */
  74 #else
  75         0,      /* 2: IVECT */
  76 #endif
  77         ZSWR3_RX_8 | ZSWR3_RX_ENABLE,
  78         ZSWR4_CLK_X16 | ZSWR4_ONESB | ZSWR4_EVENP,
  79         ZSWR5_TX_8 | ZSWR5_TX_ENABLE,
  80         0,      /* 6: TXSYNC/SYNCLO */
  81         0,      /* 7: RXSYNC/SYNCHI */
  82         0,      /* 8: alias for data port */
  83 #ifdef  ZS_INIT_IVECT
  84         ZSWR9_MASTER_IE,
  85 #else
  86         ZSWR9_MASTER_IE | ZSWR9_NO_VECTOR,
  87 #endif
  88         0,      /*10: Misc. TX/RX control bits */
  89         ZSWR11_TXCLK_BAUD | ZSWR11_RXCLK_BAUD,
  90         14,     /*12: BAUDLO (default=9600) */
  91         0,      /*13: BAUDHI (default=9600) */
  92         ZSWR14_BAUD_ENA | ZSWR14_BAUD_FROM_PCLK,
  93         ZSWR15_BREAK_IE,
  94 };
  95
  96 /*
  97  * This replaces "zs_reset()" in the sparc driver.
  98  */
  99 static void
 100 zs_setparam(struct zs_chanstate *cs, int iena, int rate)
 101 {
 102         int s, tconst;
 103
 104         memcpy(cs->cs_preg, zs_kgdb_regs, 16);
 105
 106         if (iena) {
 107                 cs->cs_preg[1] = ZSWR1_RIE | ZSWR1_SIE;
 108         }
 109
 110         /* Initialize the speed, etc. */
 111         tconst = BPS_TO_TCONST(cs->cs_brg_clk, rate);
 112         cs->cs_preg[5] |= ZSWR5_DTR | ZSWR5_RTS;
 113         cs->cs_preg[12] = tconst;
 114         cs->cs_preg[13] = tconst >> 8;
 115
 116         s = splhigh();
 117         zs_loadchannelregs(cs);
 118         splx(s);
 119 }
 120
 121 /*
 122  * Set up for kgdb; called at boot time before configuration.
 123  * KGDB interrupts will be enabled later when zs0 is configured.
 124  * Called after cninit(), so printf() etc. works.
 125  */
 126 void
 127 zs_kgdb_init(void)
 128 {
 129         struct zs_chanstate cs;
 130         struct zsdevice *zsd;
 131         volatile struct zschan *zc;
 132         int channel, promzs_unit;
 133         extern const struct cdevsw zstty_cdevsw;
 134
 135         /* printf("zs_kgdb_init: kgdb_dev=0x%x\n", kgdb_dev); */
 136         if (cdevsw_lookup(kgdb_dev) != &zstty_cdevsw)
 137                 return;
 138
 139         /* Note: (ttya,ttyb) on zs0, and (ttyc,ttyd) on zs2 */
 140         promzs_unit = (kgdb_dev & 2) ? 2 : 0;
 141         channel  =  kgdb_dev & 1;
 142         printf("zs_kgdb_init: attaching tty%c at %d baud\n",
 143                    'a' + (kgdb_dev & 3), kgdb_rate);
 144
 145         /* Setup temporary chanstate. */
 146         memset((void *)&cs, 0, sizeof(cs));
 147         zsd = zs_find_prom(promzs_unit);
 148         if (zsd == NULL) {
 149                 printf("zs_kgdb_init: zs not mapped.\n");
 150                 return;
 151         }
 152         zc = (channel == 0) ? &zsd->zs_chan_a : &zsd->zs_chan_b;
 153
 154         cs.cs_channel = channel;
 155         cs.cs_brg_clk = PCLK / 16;
 156         cs.cs_reg_csr  = &zc->zc_csr;
 157         cs.cs_reg_data = &zc->zc_data;
 158
 159         /* Now set parameters. (interrupts disabled) */
 160         zs_setparam(&cs, 0, kgdb_rate);
 161
 162         /* Store the getc/putc functions and arg. */
 163         kgdb_attach(zs_getc, zs_putc, __UNVOLATILE(zc));
 164 }
 165
 166 /*
 167  * This is a "hook" called by zstty_attach to allow the tty
 168  * to be "taken over" for exclusive use by kgdb.
 169  * Return non-zero if this is the kgdb port.
 170  *
 171  * Set the speed to kgdb_rate, CS8, etc.
 172  */
 173 int
 174 zs_check_kgdb(struct zs_chanstate *cs, int dev)
 175 {
 176
 177         if (dev != kgdb_dev)
 178                 return (0);
 179
 180         /*
 181          * Yes, this is port in use by kgdb.
 182          */
 183         cs->cs_private = NULL;
 184         cs->cs_ops = &zsops_kgdb;
 185
 186         /* Now set parameters. (interrupts enabled) */
 187         zs_setparam(cs, 1, kgdb_rate);
 188
 189         return (1);
 190 }
 191
 192 /*
 193  * KGDB framing character received: enter kernel debugger.  This probably
 194  * should time out after a few seconds to avoid hanging on spurious input.
 195  */
 196 void
 197 zskgdb(struct zs_chanstate *cs)
 198 {
 199         int unit = minor(kgdb_dev);
 200
 201         printf("zstty%d: kgdb interrupt\n", unit);
 202         /* This will trap into the debugger. */
 203         kgdb_connect(1);
 204 }
 205
 206
 207 /****************************************************************
 208  * Interface to the lower layer (zscc)
 209  ****************************************************************/
 210
 211 static void zs_kgdb_rxint(struct zs_chanstate *);
 212 static void zs_kgdb_stint(struct zs_chanstate *, int);
 213 static void zs_kgdb_txint(struct zs_chanstate *);
 214 static void zs_kgdb_softint(struct zs_chanstate *);
 215
 216 int kgdb_input_lost;
 217
 218 static void
 219 zs_kgdb_rxint(struct zs_chanstate *cs)
 220 {
 221         u_char c, rr1;
 222
 223         /*
 224          * First read the status, because reading the received char
 225          * destroys the status of this char.
 226          */
 227         rr1 = zs_read_reg(cs, 1);
 228         c = zs_read_data(cs);
 229
 230         if (rr1 & (ZSRR1_FE | ZSRR1_DO | ZSRR1_PE)) {
 231                 /* Clear the receive error. */
 232                 zs_write_csr(cs, ZSWR0_RESET_ERRORS);
 233         }
 234
 235         if (c == KGDB_START) {
 236                 zskgdb(cs);
 237         } else {
 238                 kgdb_input_lost++;
 239         }
 240 }
 241
 242 static void
 243 zs_kgdb_txint(struct zs_chanstate *cs)
 244 {
 245         int rr0;
 246
 247         rr0 = zs_read_csr(cs);
 248         zs_write_csr(cs, ZSWR0_RESET_TXINT);
 249 }
 250
 251 static void
 252 zs_kgdb_stint(struct zs_chanstate *cs, int force)
 253 {
 254         int rr0;
 255
 256         rr0 = zs_read_csr(cs);
 257         zs_write_csr(cs, ZSWR0_RESET_STATUS);
 258
 259         /*
 260          * Check here for console break, so that we can abort
 261          * even when interrupts are locking up the machine.
 262          */
 263         if (rr0 & ZSRR0_BREAK) {
 264                 zskgdb(cs);
 265         }
 266 }
 267
 268 static void
 269 zs_kgdb_softint(struct zs_chanstate *cs)
 270 {
 271         printf("zs_kgdb_softint?\n");
 272 }
 273
 274 struct zsops zsops_kgdb = {
 275         zs_kgdb_rxint,  /* receive char available */
 276         zs_kgdb_stint,  /* external/status */
 277         zs_kgdb_txint,  /* xmit buffer empty */
 278         zs_kgdb_softint,        /* process software interrupt */
 279 };