xref: /freebsd/sys/powerpc/powernv/opal_dbg.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
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 
34 struct 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 
44 static gdb_probe_f uart_opal_dbg_probe;
45 static gdb_init_f uart_opal_dbg_init;
46 static gdb_term_f uart_opal_dbg_term;
47 static gdb_getc_f uart_opal_dbg_getc;
48 static gdb_putc_f uart_opal_dbg_putc;
49 
50 GDB_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 
54 static int64_t termnum;
55 
56 static int
57 uart_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 
87 static void
88 uart_opal_dbg_init(void)
89 {
90 }
91 
92 static void
93 uart_opal_dbg_term(void)
94 {
95 }
96 
97 static int
98 uart_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 
123 static void
124 uart_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