FreeBSD/Linux Kernel Cross Reference
sys/dev/dcons/dcons.c
1 /*-
2 * SPDX-License-Identifier: BSD-4-Clause
3 *
4 * Copyright (C) 2003,2004
5 * Hidetoshi Shimokawa. 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 * 3. All advertising materials mentioning features or use of this software
16 * must display the following acknowledgement:
17 *
18 * This product includes software developed by Hidetoshi Shimokawa.
19 *
20 * 4. Neither the name of the author nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 * $Id: dcons.c,v 1.65 2003/10/24 03:24:55 simokawa Exp $
37 * $FreeBSD$
38 */
39
40 #include <sys/param.h>
41
42 #if defined(_BOOT)
43 #include "dcons.h"
44 #include "stand.h"
45 #else
46 #include <dev/dcons/dcons.h>
47 #endif
48
49 int
50 dcons_ischar(struct dcons_softc *dc)
51 {
52 u_int32_t ptr, pos, gen, next_gen;
53 struct dcons_ch *ch;
54
55 ch = &dc->i;
56
57 ptr = ntohl(*ch->ptr);
58 gen = ptr >> DCONS_GEN_SHIFT;
59 pos = ptr & DCONS_POS_MASK;
60 if (gen == ch->gen && pos == ch->pos)
61 return (0);
62
63 next_gen = DCONS_NEXT_GEN(ch->gen);
64 /* XXX sanity check */
65 if ((gen != ch->gen && gen != next_gen)
66 || (gen == ch->gen && pos < ch->pos)) {
67 /* generation skipped !! */
68 /* XXX discard */
69 ch->gen = gen;
70 ch->pos = pos;
71 return (0);
72 }
73
74 return (1);
75 }
76
77 int
78 dcons_checkc(struct dcons_softc *dc)
79 {
80 unsigned char c;
81 u_int32_t ptr, pos, gen, next_gen;
82 struct dcons_ch *ch;
83
84 ch = &dc->i;
85
86 ptr = ntohl(*ch->ptr);
87 gen = ptr >> DCONS_GEN_SHIFT;
88 pos = ptr & DCONS_POS_MASK;
89 if (gen == ch->gen && pos == ch->pos)
90 return (-1);
91
92 next_gen = DCONS_NEXT_GEN(ch->gen);
93 /* XXX sanity check */
94 if ((gen != ch->gen && gen != next_gen)
95 || (gen == ch->gen && pos < ch->pos)) {
96 /* generation skipped !! */
97 /* XXX discard */
98 ch->gen = gen;
99 ch->pos = pos;
100 return (-1);
101 }
102
103 c = ch->buf[ch->pos];
104 ch->pos ++;
105 if (ch->pos >= ch->size) {
106 ch->gen = next_gen;
107 ch->pos = 0;
108 }
109
110 return (c);
111 }
112
113 void
114 dcons_putc(struct dcons_softc *dc, int c)
115 {
116 struct dcons_ch *ch;
117
118 ch = &dc->o;
119
120 ch->buf[ch->pos] = c;
121 ch->pos ++;
122 if (ch->pos >= ch->size) {
123 ch->gen = DCONS_NEXT_GEN(ch->gen);
124 ch->pos = 0;
125 }
126 *ch->ptr = DCONS_MAKE_PTR(ch);
127 }
128
129 static int
130 dcons_init_port(int port, int offset, int size, struct dcons_buf *buf,
131 struct dcons_softc *sc)
132 {
133 int osize;
134 struct dcons_softc *dc;
135
136 dc = &sc[port];
137
138 osize = size * 3 / 4;
139
140 dc->o.size = osize;
141 dc->i.size = size - osize;
142 dc->o.buf = (char *)buf + offset;
143 dc->i.buf = dc->o.buf + osize;
144 dc->o.gen = dc->i.gen = 0;
145 dc->o.pos = dc->i.pos = 0;
146 dc->o.ptr = &buf->optr[port];
147 dc->i.ptr = &buf->iptr[port];
148 dc->brk_state = STATE0;
149 buf->osize[port] = htonl(osize);
150 buf->isize[port] = htonl(size - osize);
151 buf->ooffset[port] = htonl(offset);
152 buf->ioffset[port] = htonl(offset + osize);
153 buf->optr[port] = DCONS_MAKE_PTR(&dc->o);
154 buf->iptr[port] = DCONS_MAKE_PTR(&dc->i);
155
156 return(0);
157 }
158
159 int
160 dcons_load_buffer(struct dcons_buf *buf, int size, struct dcons_softc *sc)
161 {
162 int port, s;
163 struct dcons_softc *dc;
164
165 if (buf->version != htonl(DCONS_VERSION))
166 return (-1);
167
168 s = DCONS_HEADER_SIZE;
169 for (port = 0; port < DCONS_NPORT; port ++) {
170 dc = &sc[port];
171 dc->o.size = ntohl(buf->osize[port]);
172 dc->i.size = ntohl(buf->isize[port]);
173 dc->o.buf = (char *)buf + ntohl(buf->ooffset[port]);
174 dc->i.buf = (char *)buf + ntohl(buf->ioffset[port]);
175 dc->o.gen = ntohl(buf->optr[port]) >> DCONS_GEN_SHIFT;
176 dc->i.gen = ntohl(buf->iptr[port]) >> DCONS_GEN_SHIFT;
177 dc->o.pos = ntohl(buf->optr[port]) & DCONS_POS_MASK;
178 dc->i.pos = ntohl(buf->iptr[port]) & DCONS_POS_MASK;
179 dc->o.ptr = &buf->optr[port];
180 dc->i.ptr = &buf->iptr[port];
181 dc->brk_state = STATE0;
182
183 s += dc->o.size + dc->i.size;
184 }
185
186 /* sanity check */
187 if (s > size)
188 return (-1);
189
190 buf->magic = ntohl(DCONS_MAGIC);
191
192 return (0);
193 }
194
195 void
196 dcons_init(struct dcons_buf *buf, int size, struct dcons_softc *sc)
197 {
198 int size0, size1, offset;
199
200 offset = DCONS_HEADER_SIZE;
201 size0 = (size - offset);
202 size1 = size0 * 3 / 4; /* console port buffer */
203
204 dcons_init_port(0, offset, size1, buf, sc);
205 offset += size1;
206 dcons_init_port(1, offset, size0 - size1, buf, sc);
207 buf->version = htonl(DCONS_VERSION);
208 buf->magic = ntohl(DCONS_MAGIC);
209 }
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