xref: /freebsd/sys/powerpc/powernv/opal_dbg.c (revision 4543ef516683042d46f3bd3bb8a4f3f746e00499)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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 #include <sys/linker_set.h>
29 #include <sys/param.h>
30 #include <sys/types.h>
31 
32 struct thread;
33 
34 #include <vm/vm.h>
35 #include <vm/pmap.h>
36 
37 #include <dev/ofw/openfirm.h>
38 #include <gdb/gdb.h>
39 
40 #include "opal.h"
41 
42 static gdb_probe_f uart_opal_dbg_probe;
43 static gdb_init_f uart_opal_dbg_init;
44 static gdb_term_f uart_opal_dbg_term;
45 static gdb_getc_f uart_opal_dbg_getc;
46 static gdb_putc_f uart_opal_dbg_putc;
47 
48 GDB_DBGPORT(uart_opal, uart_opal_dbg_probe,
49     uart_opal_dbg_init, uart_opal_dbg_term,
50     uart_opal_dbg_getc, uart_opal_dbg_putc);
51 
52 static int64_t termnum;
53 
54 static int
55 uart_opal_dbg_probe(void)
56 {
57 	char buf[64];
58 	cell_t reg;
59 	phandle_t dev;
60 
61 	if (!getenv_string("hw.uart.dbgport", buf, sizeof(buf)))
62 		return (-1);
63 	if ((dev = OF_finddevice(buf)) == -1)
64 		return (-1);
65 
66 	if (OF_getprop(dev, "device_type", buf, sizeof(buf)) == -1)
67 		return (-1);
68 	if (strcmp(buf, "serial") != 0)
69 		return (-1);
70 
71 	if (OF_getprop(dev, "compatible", buf, sizeof(buf)) == -1)
72 		return (-1);
73 	if (strcmp(buf, "ibm,opal-console-raw") != 0)
74 		return (-1);
75 
76 	reg = ~0U;
77 	OF_getencprop(dev, "reg", &reg, sizeof(reg));
78 	if (reg == ~0U)
79 		return (-1);
80 	termnum = reg;
81 
82 	return (0);
83 }
84 
85 static void
86 uart_opal_dbg_init(void)
87 {
88 }
89 
90 static void
91 uart_opal_dbg_term(void)
92 {
93 }
94 
95 static int
96 uart_opal_dbg_getc(void)
97 {
98 	char c;
99 	int err;
100 	int64_t len;
101 	uint64_t lenp, bufp;
102 
103 	len = 1;
104 	if (pmap_bootstrapped) {
105 		lenp = vtophys(&len);
106 		bufp = vtophys(&c);
107 	} else {
108 		lenp = (uint64_t)&len;
109 		bufp = (uint64_t)&c;
110 	}
111 
112 	err = opal_call(OPAL_CONSOLE_READ, termnum, lenp, bufp);
113 	if (err != OPAL_SUCCESS || len != 1)
114 		return (-1);
115 
116 	opal_call(OPAL_POLL_EVENTS, NULL);
117 
118 	return (c);
119 }
120 
121 static void
122 uart_opal_dbg_putc(int c)
123 {
124 	char ch;
125 	int err;
126 	int64_t len;
127 	uint64_t lenp, bufp;
128 
129 	ch = (unsigned char)c;
130 	len = 1;
131 	if (pmap_bootstrapped) {
132 		lenp = vtophys(&len);
133 		bufp = vtophys(&ch);
134 	} else {
135 		lenp = (uint64_t)&len;
136 		bufp = (uint64_t)&ch;
137 	}
138 
139 	for (;;) {
140 		err = opal_call(OPAL_CONSOLE_WRITE, termnum, lenp, bufp);
141 		/* Clear FIFO if needed. */
142 		if (err == OPAL_BUSY_EVENT)
143 			opal_call(OPAL_POLL_EVENTS, NULL);
144 		else
145 			/* break on success or unrecoverable errors */
146 			break;
147 	}
148 	DELAY(100);
149 }
150