xref: /freebsd/sys/powerpc/pseries/phyp_dbg.c (revision 02e9120893770924227138ba49df1edb3896112a)
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 
30 #include <dev/ofw/openfirm.h>
31 #include <gdb/gdb.h>
32 
33 #include "phyp-hvcall.h"
34 
35 static gdb_probe_f uart_phyp_dbg_probe;
36 static gdb_init_f uart_phyp_dbg_init;
37 static gdb_term_f uart_phyp_dbg_term;
38 static gdb_getc_f uart_phyp_dbg_getc;
39 static gdb_putc_f uart_phyp_dbg_putc;
40 
41 GDB_DBGPORT(uart_phyp, uart_phyp_dbg_probe,
42     uart_phyp_dbg_init, uart_phyp_dbg_term,
43     uart_phyp_dbg_getc, uart_phyp_dbg_putc);
44 
45 static struct uart_phyp_dbgport {
46 	cell_t vtermid;
47 	union {
48 		uint64_t u64[2];
49 		char str[16];
50 	} inbuf;
51 	uint64_t inbuflen;
52 } dbgport;
53 
54 static int
55 uart_phyp_dbg_probe(void)
56 {
57 	char buf[64];
58 	cell_t reg;
59 	phandle_t vty;
60 
61 	if (!getenv_string("hw.uart.dbgport", buf, sizeof(buf)))
62 		return (-1);
63 
64 	if ((vty = OF_finddevice(buf)) == -1)
65 		return (-1);
66 
67 	if (OF_getprop(vty, "name", buf, sizeof(buf)) <= 0)
68 		return (-1);
69 	if (strcmp(buf, "vty") != 0)
70 		return (-1);
71 
72 	if (OF_getprop(vty, "device_type", buf, sizeof(buf)) == -1)
73 		return (-1);
74 	if (strcmp(buf, "serial") != 0)
75 		return (-1);
76 
77 	if (OF_getprop(vty, "compatible", buf, sizeof(buf)) <= 0)
78 		return (-1);
79 	if (strcmp(buf, "hvterm1") != 0)
80 		return (-1);
81 
82 	reg = ~0U;
83 	OF_getencprop(vty, "reg", &reg, sizeof(reg));
84 	if (reg == ~0U)
85 		return (-1);
86 
87 	dbgport.vtermid = reg;
88 	dbgport.inbuflen = 0;
89 
90 	return (0);
91 }
92 
93 static void
94 uart_phyp_dbg_init(void)
95 {
96 }
97 
98 static void
99 uart_phyp_dbg_term(void)
100 {
101 }
102 
103 static int
104 uart_phyp_dbg_getc(void)
105 {
106 	int c, err, next;
107 
108 	if (dbgport.inbuflen == 0) {
109 		err = phyp_pft_hcall(H_GET_TERM_CHAR, dbgport.vtermid,
110 		    0, 0, 0, &dbgport.inbuflen, &dbgport.inbuf.u64[0],
111 		    &dbgport.inbuf.u64[1]);
112 		if (err != H_SUCCESS)
113 			return (-1);
114 	}
115 
116 	if (dbgport.inbuflen == 0)
117 		return (-1);
118 
119 	c = dbgport.inbuf.str[0];
120 	dbgport.inbuflen--;
121 
122 	if (dbgport.inbuflen == 0)
123 		return (c);
124 
125 	/*
126 	 * Since version 2.11.0, QEMU became bug-compatible
127 	 * with PowerVM's vty, by inserting a \0 after every \r.
128 	 * Filter it here.
129 	 */
130 	next = 1;
131 	if (c == '\r' && dbgport.inbuf.str[next] == '\0') {
132 		next++;
133 		dbgport.inbuflen--;
134 	}
135 
136 	if (dbgport.inbuflen > 0)
137 		memmove(&dbgport.inbuf.str[0], &dbgport.inbuf.str[next],
138 		    dbgport.inbuflen);
139 
140 	return (c);
141 }
142 
143 static void
144 uart_phyp_dbg_putc(int c)
145 {
146 	int	err;
147 
148 	union {
149 		uint64_t u64;
150 		unsigned char bytes[8];
151 	} cbuf;
152 
153 	cbuf.bytes[0] = (unsigned char)c;
154 
155 	do {
156 		err = phyp_hcall(H_PUT_TERM_CHAR, dbgport.vtermid, 1,
157 		    cbuf.u64, 0);
158 		DELAY(100);
159 	} while (err == H_BUSY);
160 }
161