sys/arch/sparc/dev/zs_kgdb.c

   1 /*      $NetBSD: zs_kgdb.c,v 1.20 2009/03/18 17:06:46 cegger 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 1.20 2009/03/18 17:06:46 cegger 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/autoconf.h>
  61 #include <machine/promlib.h>
  62 #include <sparc/dev/cons.h>
  63
  64 /* Suns provide a 4.9152 MHz clock to the ZS chips. */
  65 #define PCLK    (9600 * 512)    /* PCLK pin input clock rate */
  66
  67 /* The layout of this is hardware-dependent (padding, order). */
  68 struct zschan {
  69         volatile u_char zc_csr;         /* ctrl,status, and indirect access */
  70         u_char          zc_xxx0;
  71         volatile u_char zc_data;        /* data */
  72         u_char          zc_xxx1;
  73 };
  74 struct zsdevice {
  75         /* Yes, they are backwards. */
  76         struct  zschan zs_chan_b;
  77         struct  zschan zs_chan_a;
  78 };
  79
  80 static void zs_setparam(struct zs_chanstate *, int, int);
  81 static void *findzs(int);
  82 struct zsops zsops_kgdb;
  83
  84 extern int  zs_getc(void *);
  85 extern void zs_putc(void *, int);
  86
  87 static u_char zs_kgdb_regs[16] = {
  88         0,      /* 0: CMD (reset, etc.) */
  89         0,      /* 1: No interrupts yet. */
  90         0,      /* 2: IVECT */
  91         ZSWR3_RX_8 | ZSWR3_RX_ENABLE,
  92         ZSWR4_CLK_X16 | ZSWR4_ONESB | ZSWR4_EVENP,
  93         ZSWR5_TX_8 | ZSWR5_TX_ENABLE,
  94         0,      /* 6: TXSYNC/SYNCLO */
  95         0,      /* 7: RXSYNC/SYNCHI */
  96         0,      /* 8: alias for data port */
  97         ZSWR9_MASTER_IE | ZSWR9_NO_VECTOR,
  98         0,      /*10: Misc. TX/RX control bits */
  99         ZSWR11_TXCLK_BAUD | ZSWR11_RXCLK_BAUD,
 100         14,     /*12: BAUDLO (default=9600) */
 101         0,      /*13: BAUDHI (default=9600) */
 102         ZSWR14_BAUD_ENA | ZSWR14_BAUD_FROM_PCLK,
 103         ZSWR15_BREAK_IE,
 104 };
 105
 106 /*
 107  * This replaces "zs_reset()" in the sparc driver.
 108  */
 109 static void
 110 zs_setparam(struct zs_chanstate *cs, int iena, int rate)
 111 {
 112         int s, tconst;
 113
 114         memcpy(cs->cs_preg, zs_kgdb_regs, 16);
 115
 116         if (iena) {
 117                 cs->cs_preg[1] = ZSWR1_RIE | ZSWR1_SIE;
 118         }
 119
 120         /* Initialize the speed, etc. */
 121         tconst = BPS_TO_TCONST(cs->cs_brg_clk, rate);
 122         cs->cs_preg[5] |= ZSWR5_DTR | ZSWR5_RTS;
 123         cs->cs_preg[12] = tconst;
 124         cs->cs_preg[13] = tconst >> 8;
 125
 126         s = splhigh();
 127         zs_loadchannelregs(cs);
 128         splx(s);
 129 }
 130
 131 /*
 132  * Set up for kgdb; called at boot time before configuration.
 133  * KGDB interrupts will be enabled later when zs0 is configured.
 134  * Called after cninit(), so printf() etc. works.
 135  */
 136 void
 137 zs_kgdb_init(void)
 138 {
 139         struct zs_chanstate cs;
 140         struct zsdevice *zsd;
 141         volatile struct zschan *zc;
 142         int channel, promzs_unit;
 143         extern const struct cdevsw zstty_cdevsw;
 144
 145         /* printf("zs_kgdb_init: kgdb_dev=0x%x\n", kgdb_dev); */
 146         if (cdevsw_lookup(kgdb_dev) != &zstty_cdevsw)
 147                 return;
 148
 149         /* Note: (ttya,ttyb) on zs0, and (ttyc,ttyd) on zs2 */
 150         promzs_unit = (kgdb_dev & 2) ? 2 : 0;
 151         channel  =  kgdb_dev & 1;
 152         printf("zs_kgdb_init: attaching tty%c at %d baud\n",
 153                    'a' + (kgdb_dev & 3), kgdb_rate);
 154
 155         /* Setup temporary chanstate. */
 156         memset((void *)&cs, 0, sizeof(cs));
 157         zsd = findzs(promzs_unit);
 158         if (zsd == NULL) {
 159                 printf("zs_kgdb_init: zs not mapped.\n");
 160                 return;
 161         }
 162         zc = (channel == 0) ? &zsd->zs_chan_a : &zsd->zs_chan_b;
 163
 164         cs.cs_channel = channel;
 165         cs.cs_brg_clk = PCLK / 16;
 166         cs.cs_reg_csr  = &zc->zc_csr;
 167         cs.cs_reg_data = &zc->zc_data;
 168
 169         /* Now set parameters. (interrupts disabled) */
 170         zs_setparam(&cs, 0, kgdb_rate);
 171
 172         /* Store the getc/putc functions and arg. */
 173         kgdb_attach(zs_getc, zs_putc, __UNVOLATILE(zc));
 174 }
 175
 176 /*
 177  * This is a "hook" called by zstty_attach to allow the tty
 178  * to be "taken over" for exclusive use by kgdb.
 179  * Return non-zero if this is the kgdb port.
 180  *
 181  * Set the speed to kgdb_rate, CS8, etc.
 182  */
 183 int
 184 zs_check_kgdb(struct zs_chanstate *cs, int dev)
 185 {
 186
 187         if (dev != kgdb_dev)
 188                 return (0);
 189
 190         /*
 191          * Yes, this is port in use by kgdb.
 192          */
 193         cs->cs_private = NULL;
 194         cs->cs_ops = &zsops_kgdb;
 195
 196         /* Now set parameters. (interrupts enabled) */
 197         zs_setparam(cs, 1, kgdb_rate);
 198
 199         return (1);
 200 }
 201
 202 /*
 203  * KGDB framing character received: enter kernel debugger.  This probably
 204  * should time out after a few seconds to avoid hanging on spurious input.
 205  */
 206 void
 207 zskgdb(struct zs_chanstate *cs)
 208 {
 209         int unit = minor(kgdb_dev);
 210
 211         printf("zstty%d: kgdb interrupt\n", unit);
 212         /* This will trap into the debugger. */
 213         kgdb_connect(1);
 214 }
 215
 216
 217 /****************************************************************
 218  * Interface to the lower layer (zscc)
 219  ****************************************************************/
 220
 221 static void zs_kgdb_rxint(struct zs_chanstate *);
 222 static void zs_kgdb_stint(struct zs_chanstate *, int);
 223 static void zs_kgdb_txint(struct zs_chanstate *);
 224 static void zs_kgdb_softint(struct zs_chanstate *);
 225
 226 int kgdb_input_lost;
 227
 228 static void
 229 zs_kgdb_rxint(struct zs_chanstate *cs)
 230 {
 231         register u_char c, rr1;
 232
 233         /*
 234          * First read the status, because reading the received char
 235          * destroys the status of this char.
 236          */
 237         rr1 = zs_read_reg(cs, 1);
 238         c = zs_read_data(cs);
 239
 240         if (rr1 & (ZSRR1_FE | ZSRR1_DO | ZSRR1_PE)) {
 241                 /* Clear the receive error. */
 242                 zs_write_csr(cs, ZSWR0_RESET_ERRORS);
 243         }
 244
 245         if (c == KGDB_START) {
 246                 zskgdb(cs);
 247         } else {
 248                 kgdb_input_lost++;
 249         }
 250 }
 251
 252 static void
 253 zs_kgdb_txint(struct zs_chanstate *cs)
 254 {
 255         register int rr0;
 256
 257         rr0 = zs_read_csr(cs);
 258         zs_write_csr(cs, ZSWR0_RESET_TXINT);
 259 }
 260
 261 static void
 262 zs_kgdb_stint(struct zs_chanstate *cs, int force)
 263 {
 264         register int rr0;
 265
 266         rr0 = zs_read_csr(cs);
 267         zs_write_csr(cs, ZSWR0_RESET_STATUS);
 268
 269         /*
 270          * Check here for console break, so that we can abort
 271          * even when interrupts are locking up the machine.
 272          */
 273         if (rr0 & ZSRR0_BREAK) {
 274                 zskgdb(cs);
 275         }
 276 }
 277
 278 static void
 279 zs_kgdb_softint(struct zs_chanstate *cs)
 280 {
 281
 282         printf("zs_kgdb_softint?\n");
 283 }
 284
 285 struct zsops zsops_kgdb = {
 286         zs_kgdb_rxint,  /* receive char available */
 287         zs_kgdb_stint,  /* external/status */
 288         zs_kgdb_txint,  /* xmit buffer empty */
 289         zs_kgdb_softint,        /* process software interrupt */
 290 };
 291
 292 /*
 293  * findzs() should return the address of the given zs channel.
 294  * Here we count on the PROM to map in the required zs chips.
 295  */
 296 static void *
 297 findzs(int zs)
 298 {
 299
 300 #if defined(SUN4)
 301         if (CPU_ISSUN4) {
 302                 /*
 303                  * On sun4, we use hard-coded physical addresses
 304                  */
 305 #define ZS0_PHYS        0xf1000000
 306 #define ZS1_PHYS        0xf0000000
 307 #define ZS2_PHYS        0xe0000000
 308                 bus_space_handle_t bh;
 309                 bus_addr_t paddr;
 310
 311                 switch (zs) {
 312                 case 0:
 313                         paddr = ZS0_PHYS;
 314                         break;
 315                 case 1:
 316                         paddr = ZS1_PHYS;
 317                         break;
 318                 case 2:
 319                         paddr = ZS2_PHYS;
 320                         break;
 321                 default:
 322                         return (NULL);
 323                 }
 324
 325                 if (cpuinfo.cpu_type == CPUTYP_4_100)
 326                         /* Clear top bits of physical address on 4/100 */
 327                         paddr &= ~0xf0000000;
 328
 329                 /*
 330                  * Have the obio module figure out which virtual
 331                  * address the device is mapped to.
 332                  */
 333                 if (obio_find_rom_map(paddr, PAGE_SIZE, &bh) != 0)
 334                         return (NULL);
 335
 336                 return ((void *)bh);
 337         }
 338 #endif
 339
 340 #if defined(SUN4C) || defined(SUN4M)
 341         if (CPU_ISSUN4C || CPU_ISSUN4M) {
 342                 int node;
 343
 344                 node = firstchild(findroot());
 345                 if (CPU_ISSUN4M) {
 346                         /*
 347                          * On sun4m machines zs is in "obio" tree.
 348                          */
 349                         node = findnode(node, "obio");
 350                         if (node == 0)
 351                                 panic("findzs: no obio node");
 352                         node = firstchild(node);
 353                 }
 354                 while ((node = findnode(node, "zs")) != 0) {
 355                         int nvaddrs, *vaddrs, vstore[10];
 356
 357                         if (prom_getpropint(node, "slave", -1) != zs) {
 358                                 node = nextsibling(node);
 359                                 continue;
 360                         }
 361
 362                         /*
 363                          * On some machines (e.g. the Voyager), the zs
 364                          * device has multi-valued register properties.
 365                          */
 366                         vaddrs = vstore;
 367                         nvaddrs = sizeof(vstore)/sizeof(vstore[0]);
 368                         if (prom_getprop(node, "address", sizeof(int),
 369                                     &nvaddrs, &vaddrs) != 0)
 370                                 return (NULL);
 371
 372                         return ((void *)vaddrs[0]);
 373                 }
 374         }
 375 #endif
 376         return (NULL);
 377 }