sys/arch/sun3/dev/zs_kgdb.c

   1 /*      $NetBSD: zs_kgdb.c,v 1.24 2007/10/17 19:57:45 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 1.24 2007/10/17 19:57:45 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 <sun3/dev/zs_cons.h>
  61
  62 /* The Sun3 provides a 4.9152 MHz clock to the ZS chips. */
  63 #define PCLK    (9600 * 512)    /* PCLK pin input clock rate */
  64 #define ZSHARD_PRI      6       /* Wired on the CPU board... */
  65
  66 #define ZS_DELAY()                      delay(2)
  67
  68 /* The layout of this is hardware-dependent (padding, order). */
  69 struct zschan {
  70         volatile u_char zc_csr;         /* ctrl,status, and indirect access */
  71         u_char          zc_xxx0;
  72         volatile u_char zc_data;        /* data */
  73         u_char          zc_xxx1;
  74 };
  75
  76 static void zs_setparam(struct zs_chanstate *, int, int);
  77 static void zskgdb(struct zs_chanstate *);
  78
  79 struct zsops zsops_kgdb;
  80
  81 static u_char zs_kgdb_regs[16] = {
  82         0,      /* 0: CMD (reset, etc.) */
  83         0,      /* 1: ~(ZSWR1_RIE | ZSWR1_TIE | ZSWR1_SIE) */
  84         0x18 + ZSHARD_PRI,      /* IVECT */
  85         ZSWR3_RX_8 | ZSWR3_RX_ENABLE,
  86         ZSWR4_CLK_X16 | ZSWR4_ONESB | ZSWR4_EVENP,
  87         ZSWR5_TX_8 | ZSWR5_TX_ENABLE,
  88         0,      /* 6: TXSYNC/SYNCLO */
  89         0,      /* 7: RXSYNC/SYNCHI */
  90         0,      /* 8: alias for data port */
  91         ZSWR9_MASTER_IE,
  92         0,      /*10: Misc. TX/RX control bits */
  93         ZSWR11_TXCLK_BAUD | ZSWR11_RXCLK_BAUD,
  94         14,     /*12: BAUDLO (default=9600) */
  95         0,      /*13: BAUDHI (default=9600) */
  96         ZSWR14_BAUD_FROM_PCLK | ZSWR14_BAUD_ENA,
  97         ZSWR15_BREAK_IE,
  98 };
  99
 100 /*
 101  * This replaces "zs_reset()" in the sparc driver.
 102  */
 103 static void
 104 zs_setparam(struct zs_chanstate *cs, int iena, int rate)
 105 {
 106         int s, tconst;
 107
 108         memcpy(cs->cs_preg, zs_kgdb_regs, 16);
 109
 110         if (iena) {
 111                 cs->cs_preg[1] = ZSWR1_RIE | ZSWR1_SIE;
 112         }
 113
 114         /* Initialize the speed, etc. */
 115         tconst = BPS_TO_TCONST(cs->cs_brg_clk, rate);
 116         cs->cs_preg[5] |= ZSWR5_DTR | ZSWR5_RTS;
 117         cs->cs_preg[12] = tconst;
 118         cs->cs_preg[13] = tconst >> 8;
 119
 120         s = splhigh();
 121         zs_loadchannelregs(cs);
 122         splx(s);
 123 }
 124
 125 /*
 126  * Set up for kgdb; called at boot time before configuration.
 127  * KGDB interrupts will be enabled later when zs0 is configured.
 128  * Called after cninit(), so printf() etc. works.
 129  */
 130 void
 131 zs_kgdb_init(void)
 132 {
 133         struct zs_chanstate cs;
 134         struct zschan *zc;
 135         int channel, zsc_unit;
 136         extern const struct cdevsw zstty_cdevsw;
 137
 138         /* printf("zs_kgdb_init: kgdb_dev=0x%x\n", kgdb_dev); */
 139         if (cdevsw_lookup(kgdb_dev) != &zstty_cdevsw)
 140                 return;
 141
 142         /* Note: (ttya,ttyb) on zsc1, and (ttyc,ttyd) on zsc0 */
 143         zsc_unit = (kgdb_dev & 2) ? 0 : 1;
 144         channel  =  kgdb_dev & 1;
 145         printf("zs_kgdb_init: attaching tty%c at %d baud\n",
 146                    'a' + (kgdb_dev & 3), kgdb_rate);
 147
 148         /* Setup temporary chanstate. */
 149         memset((void *)&cs, 0, sizeof(cs));
 150         zc = zs_get_chan_addr(zsc_unit, channel);
 151         if (zc == NULL) {
 152                 printf("zs_kgdb_init: zs not mapped.\n");
 153                 kgdb_dev = -1;
 154                 return;
 155         }
 156
 157         cs.cs_channel = channel;
 158         cs.cs_brg_clk = PCLK / 16;
 159         cs.cs_reg_csr  = &zc->zc_csr;
 160         cs.cs_reg_data = &zc->zc_data;
 161
 162         /* Now set parameters. (interrupts disabled) */
 163         zs_setparam(&cs, 0, kgdb_rate);
 164
 165         /* Store the getc/putc functions and arg. */
 166         kgdb_attach(zs_getc, zs_putc, __UNVOLATILE(zc));
 167 }
 168
 169 /*
 170  * This is a "hook" called by zstty_attach to allow the tty
 171  * to be "taken over" for exclusive use by kgdb.
 172  * Return non-zero if this is the kgdb port.
 173  *
 174  * Set the speed to kgdb_rate, CS8, etc.
 175  */
 176 int
 177 zs_check_kgdb(struct zs_chanstate *cs, int dev)
 178 {
 179
 180         if (dev != kgdb_dev)
 181                 return (0);
 182
 183         /*
 184          * Yes, this is port in use by kgdb.
 185          */
 186         cs->cs_private = NULL;
 187         cs->cs_ops = &zsops_kgdb;
 188
 189         /* Now set parameters. (interrupts enabled) */
 190         zs_setparam(cs, 1, kgdb_rate);
 191
 192         return (1);
 193 }
 194
 195 /*
 196  * KGDB framing character received: enter kernel debugger.  This probably
 197  * should time out after a few seconds to avoid hanging on spurious input.
 198  */
 199 static void
 200 zskgdb(struct zs_chanstate *cs)
 201 {
 202         int unit = minor(kgdb_dev);
 203
 204         printf("zstty%d: kgdb interrupt\n", unit);
 205         /* This will trap into the debugger. */
 206         kgdb_connect(1);
 207 }
 208
 209
 210 /****************************************************************
 211  * Interface to the lower layer (zscc)
 212  ****************************************************************/
 213
 214 static void zs_kgdb_rxint(struct zs_chanstate *);
 215 static void zs_kgdb_stint(struct zs_chanstate *, int);
 216 static void zs_kgdb_txint(struct zs_chanstate *);
 217 static void zs_kgdb_softint(struct zs_chanstate *);
 218
 219 int kgdb_input_lost;
 220
 221 static void
 222 zs_kgdb_rxint(struct zs_chanstate *cs)
 223 {
 224         u_char c, rr1;
 225
 226         /*
 227          * First read the status, because reading the received char
 228          * destroys the status of this char.
 229          */
 230         rr1 = zs_read_reg(cs, 1);
 231         c = zs_read_data(cs);
 232
 233         if (rr1 & (ZSRR1_FE | ZSRR1_DO | ZSRR1_PE)) {
 234                 /* Clear the receive error. */
 235                 zs_write_csr(cs, ZSWR0_RESET_ERRORS);
 236         }
 237
 238         if (c == KGDB_START) {
 239                 zskgdb(cs);
 240         } else {
 241                 kgdb_input_lost++;
 242         }
 243 }
 244
 245 static void
 246 zs_kgdb_txint(struct zs_chanstate *cs)
 247 {
 248         int rr0;
 249
 250         rr0 = zs_read_csr(cs);
 251         zs_write_csr(cs, ZSWR0_RESET_TXINT);
 252 }
 253
 254 static void
 255 zs_kgdb_stint(struct zs_chanstate *cs, int force)
 256 {
 257         int rr0;
 258
 259         rr0 = zs_read_csr(cs);
 260         zs_write_csr(cs, ZSWR0_RESET_STATUS);
 261
 262         /*
 263          * Check here for console break, so that we can abort
 264          * even when interrupts are locking up the machine.
 265          */
 266         if (rr0 & ZSRR0_BREAK) {
 267                 zskgdb(cs);
 268         }
 269 }
 270
 271 static void
 272 zs_kgdb_softint(struct zs_chanstate *cs)
 273 {
 274         printf("zs_kgdb_softint?\n");
 275 }
 276
 277 struct zsops zsops_kgdb = {
 278         zs_kgdb_rxint,  /* receive char available */
 279         zs_kgdb_stint,  /* external/status */
 280         zs_kgdb_txint,  /* xmit buffer empty */
 281         zs_kgdb_softint,        /* process software interrupt */
 282 };