xref: /freebsd/sys/dev/syscons/schistory.c (revision f9218d3d4fd34f082473b3a021c6d4d109fb47cf)
1 /*-
2  * Copyright (c) 1999 Kazutaka YOKOTA <yokota@zodiac.mech.utsunomiya-u.ac.jp>
3  * Copyright (c) 1992-1998 S�ren Schmidt
4  * All rights reserved.
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  *    without modification, immediately at the beginning of the file.
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. The name of the author may not be used to endorse or promote products
16  *    derived from this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  *
29  * $FreeBSD$
30  */
31 
32 #include "opt_syscons.h"
33 
34 #ifndef SC_NO_HISTORY
35 
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/conf.h>
39 #include <sys/consio.h>
40 #include <sys/tty.h>
41 #include <sys/kernel.h>
42 #include <sys/malloc.h>
43 
44 #include <machine/pc/display.h>
45 
46 #include <dev/syscons/syscons.h>
47 
48 /*
49  * XXX Placeholder.
50  * This calculations should be dynamically scaled by number of seperate sc
51  * devices.  A base value of 'extra_history_size' should be defined for
52  * each syscons unit, and added and subtracted from the dynamic
53  * 'extra_history_size' as units are added and removed.  This way, each time
54  * a new syscons unit goes online, extra_history_size is automatically bumped.
55  */
56 #define	MAXSC	1
57 
58 #if !defined(SC_MAX_HISTORY_SIZE)
59 #define SC_MAX_HISTORY_SIZE	(1000 * MAXCONS * MAXSC)
60 #endif
61 
62 #if !defined(SC_HISTORY_SIZE)
63 #define SC_HISTORY_SIZE		(ROW * 4)
64 #endif
65 
66 #if (SC_HISTORY_SIZE * MAXCONS * MAXSC) > SC_MAX_HISTORY_SIZE
67 #undef SC_MAX_HISTORY_SIZE
68 #define SC_MAX_HISTORY_SIZE	(SC_HISTORY_SIZE * MAXCONS * MAXSC)
69 #endif
70 
71 /* local variables */
72 static int		extra_history_size
73 				= SC_MAX_HISTORY_SIZE - SC_HISTORY_SIZE*MAXCONS;
74 
75 /* local functions */
76 static void copy_history(sc_vtb_t *from, sc_vtb_t *to);
77 static void history_to_screen(scr_stat *scp);
78 
79 /* allocate a history buffer */
80 int
81 sc_alloc_history_buffer(scr_stat *scp, int lines, int prev_ysize, int wait)
82 {
83 	/*
84 	 * syscons unconditionally allocates buffers upto
85 	 * SC_HISTORY_SIZE lines or scp->ysize lines, whichever
86 	 * is larger. A value greater than that is allowed,
87 	 * subject to extra_history_size.
88 	 */
89 	sc_vtb_t *history;
90 	sc_vtb_t *prev_history;
91 	int cur_lines;				/* current buffer size */
92 	int min_lines;				/* guaranteed buffer size */
93 	int delta;				/* lines to put back */
94 
95 	if (lines <= 0)
96 		lines = SC_HISTORY_SIZE;	/* use the default value */
97 
98 	/* make it at least as large as the screen size */
99 	lines = imax(lines, scp->ysize);
100 
101 	/* remove the history buffer while we update it */
102 	history = prev_history = scp->history;
103 	scp->history = NULL;
104 
105 	/* calculate the amount of lines to put back to extra_history_size */
106 	delta = 0;
107 	if (prev_history) {
108 		cur_lines = sc_vtb_rows(history);
109 		min_lines = imax(SC_HISTORY_SIZE, prev_ysize);
110 		if (cur_lines > min_lines)
111 			delta = cur_lines - min_lines;
112 	}
113 
114 	/* lines upto min_lines are always allowed. */
115 	min_lines = imax(SC_HISTORY_SIZE, scp->ysize);
116 	if (lines > min_lines) {
117 		if (lines - min_lines > extra_history_size + delta) {
118 			/* too many lines are requested */
119 			scp->history = prev_history;
120 			return EINVAL;
121 		}
122 	}
123 
124 	/* allocate a new buffer */
125 	history = (sc_vtb_t *)malloc(sizeof(*history),
126 				     M_DEVBUF,
127 				     (wait) ? M_WAITOK : M_NOWAIT);
128 	if (history != NULL) {
129 		if (lines > min_lines)
130 			extra_history_size -= lines - min_lines;
131 		/* XXX error check? */
132 		sc_vtb_init(history, VTB_RINGBUFFER, scp->xsize, lines,
133 			    NULL, wait);
134 		/* FIXME: XXX no good? */
135 		sc_vtb_clear(history, scp->sc->scr_map[0x20],
136 			     SC_NORM_ATTR << 8);
137 		if (prev_history != NULL)
138 			copy_history(prev_history, history);
139 		scp->history_pos = sc_vtb_tail(history);
140 	} else {
141 		scp->history_pos = 0;
142 	}
143 
144 	/* destroy the previous buffer */
145 	if (prev_history != NULL) {
146 		extra_history_size += delta;
147 		sc_vtb_destroy(prev_history);
148 		free(prev_history, M_DEVBUF);
149 	}
150 
151 	scp->history = history;
152 
153 	return 0;
154 }
155 
156 static void
157 copy_history(sc_vtb_t *from, sc_vtb_t *to)
158 {
159 	int lines;
160 	int cols;
161 	int cols1;
162 	int cols2;
163 	int pos;
164 	int i;
165 
166 	lines = sc_vtb_rows(from);
167 	cols1 = sc_vtb_cols(from);
168 	cols2 = sc_vtb_cols(to);
169 	cols = imin(cols1, cols2);
170 	pos = sc_vtb_tail(from);
171 	for (i = 0; i < lines; ++i) {
172 		sc_vtb_append(from, pos, to, cols);
173 		if (cols < cols2)
174 			sc_vtb_seek(to, sc_vtb_pos(to,
175 						   sc_vtb_tail(to),
176 						   cols2 - cols));
177 		pos = sc_vtb_pos(from, pos, cols1);
178 	}
179 }
180 
181 void
182 sc_free_history_buffer(scr_stat *scp, int prev_ysize)
183 {
184 	sc_vtb_t *history;
185 	int cur_lines;				/* current buffer size */
186 	int min_lines;				/* guaranteed buffer size */
187 
188 	history = scp->history;
189 	scp->history = NULL;
190 	if (history == NULL)
191 		return;
192 
193 	cur_lines = sc_vtb_rows(history);
194 	min_lines = imax(SC_HISTORY_SIZE, prev_ysize);
195 	extra_history_size += (cur_lines > min_lines) ?
196 				  cur_lines - min_lines : 0;
197 
198 	sc_vtb_destroy(history);
199 	free(history, M_DEVBUF);
200 }
201 
202 /* copy entire screen into the top of the history buffer */
203 void
204 sc_hist_save(scr_stat *scp)
205 {
206 	sc_vtb_append(&scp->vtb, 0, scp->history, scp->xsize*scp->ysize);
207 	scp->history_pos = sc_vtb_tail(scp->history);
208 }
209 
210 /* restore the screen by copying from the history buffer */
211 int
212 sc_hist_restore(scr_stat *scp)
213 {
214 	int ret;
215 
216 	if (scp->history_pos != sc_vtb_tail(scp->history)) {
217 		scp->history_pos = sc_vtb_tail(scp->history);
218 		history_to_screen(scp);
219 		ret =  0;
220 	} else {
221 		ret = 1;
222 	}
223 	sc_vtb_seek(scp->history, sc_vtb_pos(scp->history,
224 					     sc_vtb_tail(scp->history),
225 					     -scp->xsize*scp->ysize));
226 	return ret;
227 }
228 
229 /* copy screen-full of saved lines */
230 static void
231 history_to_screen(scr_stat *scp)
232 {
233 	int pos;
234 	int i;
235 
236 	pos = scp->history_pos;
237 	for (i = 1; i <= scp->ysize; ++i) {
238 		pos = sc_vtb_pos(scp->history, pos, -scp->xsize);
239 		sc_vtb_copy(scp->history, pos,
240 			    &scp->vtb, scp->xsize*(scp->ysize - i),
241 			    scp->xsize);
242 	}
243 	mark_all(scp);
244 }
245 
246 /* go to the tail of the history buffer */
247 void
248 sc_hist_home(scr_stat *scp)
249 {
250 	scp->history_pos = sc_vtb_tail(scp->history);
251 	history_to_screen(scp);
252 }
253 
254 /* go to the top of the history buffer */
255 void
256 sc_hist_end(scr_stat *scp)
257 {
258 	scp->history_pos = sc_vtb_pos(scp->history, sc_vtb_tail(scp->history),
259 				      scp->xsize*scp->ysize);
260 	history_to_screen(scp);
261 }
262 
263 /* move one line up */
264 int
265 sc_hist_up_line(scr_stat *scp)
266 {
267 	if (sc_vtb_pos(scp->history, scp->history_pos, -(scp->xsize*scp->ysize))
268 	    == sc_vtb_tail(scp->history))
269 		return -1;
270 	scp->history_pos = sc_vtb_pos(scp->history, scp->history_pos,
271 				      -scp->xsize);
272 	history_to_screen(scp);
273 	return 0;
274 }
275 
276 /* move one line down */
277 int
278 sc_hist_down_line(scr_stat *scp)
279 {
280 	if (scp->history_pos == sc_vtb_tail(scp->history))
281 		return -1;
282 	scp->history_pos = sc_vtb_pos(scp->history, scp->history_pos,
283 				      scp->xsize);
284 	history_to_screen(scp);
285 	return 0;
286 }
287 
288 int
289 sc_hist_ioctl(struct tty *tp, u_long cmd, caddr_t data, int flag,
290 	      struct thread *td)
291 {
292 	scr_stat *scp;
293 	int error;
294 
295 	switch (cmd) {
296 
297 	case CONS_HISTORY:  	/* set history size */
298 		scp = SC_STAT(tp->t_dev);
299 		if (*(int *)data <= 0)
300 			return EINVAL;
301 		if (scp->status & BUFFER_SAVED)
302 			return EBUSY;
303 		DPRINTF(5, ("lines:%d, ysize:%d, pool:%d\n",
304 			    *(int *)data, scp->ysize, extra_history_size));
305 		error = sc_alloc_history_buffer(scp,
306 					       imax(*(int *)data, scp->ysize),
307 					       scp->ysize, TRUE);
308 		DPRINTF(5, ("error:%d, rows:%d, pool:%d\n", error,
309 			    sc_vtb_rows(scp->history), extra_history_size));
310 		return error;
311 
312 	case CONS_CLRHIST:
313 		scp = SC_STAT(tp->t_dev);
314 		sc_vtb_clear(scp->history, scp->sc->scr_map[0x20],
315 		    SC_NORM_ATTR << 8);
316 		return 0;
317 	}
318 
319 	return ENOIOCTL;
320 }
321 
322 #endif /* SC_NO_HISTORY */
323