1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (C) 2019 Leandro Lupori
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
19 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
20 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
21 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
22 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
23 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
24 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD$");
29
30#include <sys/linker_set.h>
31#include <sys/param.h>
32#include <sys/types.h>
33
34struct thread;
35
36#include <vm/vm.h>
37#include <vm/pmap.h>
38
39#include <dev/ofw/openfirm.h>
40#include <gdb/gdb.h>
41
42#include "opal.h"
43
44static gdb_probe_f uart_opal_dbg_probe;
45static gdb_init_f uart_opal_dbg_init;
46static gdb_term_f uart_opal_dbg_term;
47static gdb_getc_f uart_opal_dbg_getc;
48static gdb_putc_f uart_opal_dbg_putc;
49
50GDB_DBGPORT(uart_opal, uart_opal_dbg_probe,
51    uart_opal_dbg_init, uart_opal_dbg_term,
52    uart_opal_dbg_getc, uart_opal_dbg_putc);
53
54static int64_t termnum;
55
56static int
57uart_opal_dbg_probe(void)
58{
59	char buf[64];
60	cell_t reg;
61	phandle_t dev;
62
63	if (!getenv_string("hw.uart.dbgport", buf, sizeof(buf)))
64		return (-1);
65	if ((dev = OF_finddevice(buf)) == -1)
66		return (-1);
67
68	if (OF_getprop(dev, "device_type", buf, sizeof(buf)) == -1)
69		return (-1);
70	if (strcmp(buf, "serial") != 0)
71		return (-1);
72
73	if (OF_getprop(dev, "compatible", buf, sizeof(buf)) == -1)
74		return (-1);
75	if (strcmp(buf, "ibm,opal-console-raw") != 0)
76		return (-1);
77
78	reg = ~0U;
79	OF_getencprop(dev, "reg", &reg, sizeof(reg));
80	if (reg == ~0U)
81		return (-1);
82	termnum = reg;
83
84	return (0);
85}
86
87static void
88uart_opal_dbg_init(void)
89{
90}
91
92static void
93uart_opal_dbg_term(void)
94{
95}
96
97static int
98uart_opal_dbg_getc(void)
99{
100	char c;
101	int err;
102	int64_t len;
103	uint64_t lenp, bufp;
104
105	len = 1;
106	if (pmap_bootstrapped) {
107		lenp = vtophys(&len);
108		bufp = vtophys(&c);
109	} else {
110		lenp = (uint64_t)&len;
111		bufp = (uint64_t)&c;
112	}
113
114	err = opal_call(OPAL_CONSOLE_READ, termnum, lenp, bufp);
115	if (err != OPAL_SUCCESS || len != 1)
116		return (-1);
117
118	opal_call(OPAL_POLL_EVENTS, NULL);
119
120	return (c);
121}
122
123static void
124uart_opal_dbg_putc(int c)
125{
126	char ch;
127	int err;
128	int64_t len;
129	uint64_t lenp, bufp;
130
131	ch = (unsigned char)c;
132	len = 1;
133	if (pmap_bootstrapped) {
134		lenp = vtophys(&len);
135		bufp = vtophys(&ch);
136	} else {
137		lenp = (uint64_t)&len;
138		bufp = (uint64_t)&ch;
139	}
140
141	for (;;) {
142		err = opal_call(OPAL_CONSOLE_WRITE, termnum, lenp, bufp);
143		/* Clear FIFO if needed. */
144		if (err == OPAL_BUSY_EVENT)
145			opal_call(OPAL_POLL_EVENTS, NULL);
146		else
147			/* break on success or unrecoverable errors */
148			break;
149	}
150	DELAY(100);
151}
152