xref: /freebsd/sys/dev/dcons/dcons.c (revision 3416500aef140042c64bc149cb1ec6620483bc44)
1 /*-
2  * Copyright (C) 2003,2004
3  * 	Hidetoshi Shimokawa. All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *
16  *	This product includes software developed by Hidetoshi Shimokawa.
17  *
18  * 4. Neither the name of the author nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  * $Id: dcons.c,v 1.65 2003/10/24 03:24:55 simokawa Exp $
35  * $FreeBSD$
36  */
37 
38 #include <sys/param.h>
39 
40 #if defined(_BOOT)
41 #include "dcons.h"
42 #include "stand.h"
43 #else
44 #include <dev/dcons/dcons.h>
45 #endif
46 
47 int
48 dcons_ischar(struct dcons_softc *dc)
49 {
50 	u_int32_t ptr, pos, gen, next_gen;
51 	struct dcons_ch *ch;
52 
53 	ch = &dc->i;
54 
55 	ptr = ntohl(*ch->ptr);
56 	gen = ptr >> DCONS_GEN_SHIFT;
57 	pos = ptr & DCONS_POS_MASK;
58 	if (gen == ch->gen && pos == ch->pos)
59 		return (0);
60 
61 	next_gen = DCONS_NEXT_GEN(ch->gen);
62 	/* XXX sanity check */
63 	if ((gen != ch->gen && gen != next_gen)
64 			|| (gen == ch->gen && pos < ch->pos)) {
65 		/* generation skipped !! */
66 		/* XXX discard */
67 		ch->gen = gen;
68 		ch->pos = pos;
69 		return (0);
70 	}
71 
72 	return (1);
73 }
74 
75 int
76 dcons_checkc(struct dcons_softc *dc)
77 {
78 	unsigned char c;
79 	u_int32_t ptr, pos, gen, next_gen;
80 	struct dcons_ch *ch;
81 
82 	ch = &dc->i;
83 
84 	ptr = ntohl(*ch->ptr);
85 	gen = ptr >> DCONS_GEN_SHIFT;
86 	pos = ptr & DCONS_POS_MASK;
87 	if (gen == ch->gen && pos == ch->pos)
88 		return (-1);
89 
90 	next_gen = DCONS_NEXT_GEN(ch->gen);
91 	/* XXX sanity check */
92 	if ((gen != ch->gen && gen != next_gen)
93 			|| (gen == ch->gen && pos < ch->pos)) {
94 		/* generation skipped !! */
95 		/* XXX discard */
96 		ch->gen = gen;
97 		ch->pos = pos;
98 		return (-1);
99 	}
100 
101 	c = ch->buf[ch->pos];
102 	ch->pos ++;
103 	if (ch->pos >= ch->size) {
104 		ch->gen = next_gen;
105 		ch->pos = 0;
106 	}
107 
108 	return (c);
109 }
110 
111 void
112 dcons_putc(struct dcons_softc *dc, int c)
113 {
114 	struct dcons_ch *ch;
115 
116 	ch = &dc->o;
117 
118 	ch->buf[ch->pos] = c;
119 	ch->pos ++;
120 	if (ch->pos >= ch->size) {
121 		ch->gen = DCONS_NEXT_GEN(ch->gen);
122 		ch->pos = 0;
123 	}
124 	*ch->ptr = DCONS_MAKE_PTR(ch);
125 }
126 
127 static int
128 dcons_init_port(int port, int offset, int size, struct dcons_buf *buf,
129     struct dcons_softc *sc)
130 {
131 	int osize;
132 	struct dcons_softc *dc;
133 
134 	dc = &sc[port];
135 
136 	osize = size * 3 / 4;
137 
138 	dc->o.size = osize;
139 	dc->i.size = size - osize;
140 	dc->o.buf = (char *)buf + offset;
141 	dc->i.buf = dc->o.buf + osize;
142 	dc->o.gen = dc->i.gen = 0;
143 	dc->o.pos = dc->i.pos = 0;
144 	dc->o.ptr = &buf->optr[port];
145 	dc->i.ptr = &buf->iptr[port];
146 	dc->brk_state = STATE0;
147 	buf->osize[port] = htonl(osize);
148 	buf->isize[port] = htonl(size - osize);
149 	buf->ooffset[port] = htonl(offset);
150 	buf->ioffset[port] = htonl(offset + osize);
151 	buf->optr[port] = DCONS_MAKE_PTR(&dc->o);
152 	buf->iptr[port] = DCONS_MAKE_PTR(&dc->i);
153 
154 	return(0);
155 }
156 
157 int
158 dcons_load_buffer(struct dcons_buf *buf, int size, struct dcons_softc *sc)
159 {
160 	int port, s;
161 	struct dcons_softc *dc;
162 
163 	if (buf->version != htonl(DCONS_VERSION))
164 		return (-1);
165 
166 	s = DCONS_HEADER_SIZE;
167 	for (port = 0; port < DCONS_NPORT; port ++) {
168 		dc = &sc[port];
169 		dc->o.size = ntohl(buf->osize[port]);
170 		dc->i.size = ntohl(buf->isize[port]);
171 		dc->o.buf = (char *)buf + ntohl(buf->ooffset[port]);
172 		dc->i.buf = (char *)buf + ntohl(buf->ioffset[port]);
173 		dc->o.gen = ntohl(buf->optr[port]) >> DCONS_GEN_SHIFT;
174 		dc->i.gen = ntohl(buf->iptr[port]) >> DCONS_GEN_SHIFT;
175 		dc->o.pos = ntohl(buf->optr[port]) & DCONS_POS_MASK;
176 		dc->i.pos = ntohl(buf->iptr[port]) & DCONS_POS_MASK;
177 		dc->o.ptr = &buf->optr[port];
178 		dc->i.ptr = &buf->iptr[port];
179 		dc->brk_state = STATE0;
180 
181 		s += dc->o.size + dc->i.size;
182 	}
183 
184 	/* sanity check */
185 	if (s > size)
186 		return (-1);
187 
188 	buf->magic = ntohl(DCONS_MAGIC);
189 
190 	return (0);
191 }
192 
193 void
194 dcons_init(struct dcons_buf *buf, int size, struct dcons_softc *sc)
195 {
196 	int size0, size1, offset;
197 
198 	offset = DCONS_HEADER_SIZE;
199 	size0 = (size - offset);
200 	size1 = size0 * 3 / 4;		/* console port buffer */
201 
202 	dcons_init_port(0, offset, size1, buf, sc);
203 	offset += size1;
204 	dcons_init_port(1, offset, size0 - size1, buf, sc);
205 	buf->version = htonl(DCONS_VERSION);
206 	buf->magic = ntohl(DCONS_MAGIC);
207 }
208