xref: /freebsd-12.1/sys/dev/bvm/bvm_dbg.c (revision 718cf2cc)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2011 NetApp, Inc.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  *
28  * $FreeBSD$
29  */
30 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 #include <sys/param.h>
35 #include <sys/kernel.h>
36 #include <sys/bus.h>
37 
38 #include <gdb/gdb.h>
39 
40 #include <machine/cpufunc.h>
41 
42 static gdb_probe_f bvm_dbg_probe;
43 static gdb_init_f bvm_dbg_init;
44 static gdb_term_f bvm_dbg_term;
45 static gdb_getc_f bvm_dbg_getc;
46 static gdb_putc_f bvm_dbg_putc;
47 
48 GDB_DBGPORT(bvm, bvm_dbg_probe, bvm_dbg_init, bvm_dbg_term,
49     bvm_dbg_getc, bvm_dbg_putc);
50 
51 #define	BVM_DBG_PORT	0x224
52 static int bvm_dbg_port = BVM_DBG_PORT;
53 
54 #define BVM_DBG_SIG	('B' << 8 | 'V')
55 
56 static int
bvm_dbg_probe(void)57 bvm_dbg_probe(void)
58 {
59 	int disabled, port;
60 
61 	disabled = 0;
62 	resource_int_value("bvmdbg", 0, "disabled", &disabled);
63 
64 	if (!disabled) {
65 		if (resource_int_value("bvmdbg", 0, "port", &port) == 0)
66 			bvm_dbg_port = port;
67 
68 		if (inw(bvm_dbg_port) == BVM_DBG_SIG) {
69 			/*
70 			 * Return a higher priority than 0 to override other
71 			 * gdb dbgport providers that may be present (e.g. uart)
72 			 */
73 			return (1);
74 		}
75 	}
76 
77 	return (-1);
78 }
79 
80 static void
bvm_dbg_init(void)81 bvm_dbg_init(void)
82 {
83 }
84 
85 static void
bvm_dbg_term(void)86 bvm_dbg_term(void)
87 {
88 }
89 
90 static void
bvm_dbg_putc(int c)91 bvm_dbg_putc(int c)
92 {
93 
94 	outl(bvm_dbg_port, c);
95 }
96 
97 static int
bvm_dbg_getc(void)98 bvm_dbg_getc(void)
99 {
100 
101 	return (inl(bvm_dbg_port));
102 }
103