1 /* $NetBSD: zs_kgdb.c,v 1.22 2023/10/24 19:05:07 andvar 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 1.22 2023/10/24 19:05:07 andvar 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
zs_setparam(struct zs_chanstate * cs,int iena,int rate)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
zs_kgdb_init(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 Serial(%lld) at %d baud\n",
153 (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
zs_check_kgdb(struct zs_chanstate * cs,int dev)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
zskgdb(struct zs_chanstate * cs)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
zs_kgdb_rxint(struct zs_chanstate * cs)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
zs_kgdb_txint(struct zs_chanstate * cs)253 zs_kgdb_txint(struct zs_chanstate *cs)
254 {
255 zs_write_csr(cs, ZSWR0_RESET_TXINT);
256 }
257
258 static void
zs_kgdb_stint(struct zs_chanstate * cs,int force)259 zs_kgdb_stint(struct zs_chanstate *cs, int force)
260 {
261 register int rr0;
262
263 rr0 = zs_read_csr(cs);
264 zs_write_csr(cs, ZSWR0_RESET_STATUS);
265
266 /*
267 * Check here for console break, so that we can abort
268 * even when interrupts are locking up the machine.
269 */
270 if (rr0 & ZSRR0_BREAK) {
271 zskgdb(cs);
272 }
273 }
274
275 static void
zs_kgdb_softint(struct zs_chanstate * cs)276 zs_kgdb_softint(struct zs_chanstate *cs)
277 {
278
279 printf("zs_kgdb_softint?\n");
280 }
281
282 struct zsops zsops_kgdb = {
283 zs_kgdb_rxint, /* receive char available */
284 zs_kgdb_stint, /* external/status */
285 zs_kgdb_txint, /* xmit buffer empty */
286 zs_kgdb_softint, /* process software interrupt */
287 };
288
289 /*
290 * findzs() should return the address of the given zs channel.
291 * Here we count on the PROM to map in the required zs chips.
292 */
293 static void *
findzs(int zs)294 findzs(int zs)
295 {
296
297 #if defined(SUN4)
298 if (CPU_ISSUN4) {
299 /*
300 * On sun4, we use hard-coded physical addresses
301 */
302 #define ZS0_PHYS 0xf1000000
303 #define ZS1_PHYS 0xf0000000
304 #define ZS2_PHYS 0xe0000000
305 bus_space_handle_t bh;
306 bus_addr_t paddr;
307
308 switch (zs) {
309 case 0:
310 paddr = ZS0_PHYS;
311 break;
312 case 1:
313 paddr = ZS1_PHYS;
314 break;
315 case 2:
316 paddr = ZS2_PHYS;
317 break;
318 default:
319 return (NULL);
320 }
321
322 if (cpuinfo.cpu_type == CPUTYP_4_100)
323 /* Clear top bits of physical address on 4/100 */
324 paddr &= ~0xf0000000;
325
326 /*
327 * Have the obio module figure out which virtual
328 * address the device is mapped to.
329 */
330 if (obio_find_rom_map(paddr, PAGE_SIZE, &bh) != 0)
331 return (NULL);
332
333 return ((void *)bh);
334 }
335 #endif
336
337 #if defined(SUN4C) || defined(SUN4M)
338 if (CPU_ISSUN4C || CPU_ISSUN4M) {
339 int node;
340
341 node = firstchild(findroot());
342 if (CPU_ISSUN4M) {
343 /*
344 * On sun4m machines zs is in "obio" tree.
345 */
346 node = findnode(node, "obio");
347 if (node == 0)
348 panic("findzs: no obio node");
349 node = firstchild(node);
350 }
351 while ((node = findnode(node, "zs")) != 0) {
352 int nvaddrs, *vaddrs, vstore[10];
353
354 if (prom_getpropint(node, "slave", -1) != zs) {
355 node = nextsibling(node);
356 continue;
357 }
358
359 /*
360 * On some machines (e.g. the Voyager), the zs
361 * device has multi-valued register properties.
362 */
363 vaddrs = vstore;
364 nvaddrs = sizeof(vstore)/sizeof(vstore[0]);
365 if (prom_getprop(node, "address", sizeof(int),
366 &nvaddrs, &vaddrs) != 0)
367 return (NULL);
368
369 return ((void *)vaddrs[0]);
370 }
371 }
372 #endif
373 return (NULL);
374 }
375