xref: /freebsd/sys/dev/syscons/schistory.c (revision b9f654b163bce26de79705e77b872427c9f2afa1)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1999 Kazutaka YOKOTA <yokota@zodiac.mech.utsunomiya-u.ac.jp>
5  * Copyright (c) 1992-1998 Søren Schmidt
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer,
13  *    without modification, immediately at the beginning of the file.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. The name of the author may not be used to endorse or promote products
18  *    derived from this software without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
21  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
23  * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
24  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
25  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
29  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include "opt_syscons.h"
36 
37 #ifndef SC_NO_HISTORY
38 
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/conf.h>
42 #include <sys/consio.h>
43 #include <sys/tty.h>
44 #include <sys/kernel.h>
45 #include <sys/malloc.h>
46 
47 #if defined(__arm__) || defined(__mips__) || \
48 	defined(__powerpc__) || defined(__sparc64__)
49 #include <machine/sc_machdep.h>
50 #else
51 #include <machine/pc/display.h>
52 #endif
53 
54 #include <dev/syscons/syscons.h>
55 
56 /*
57  * XXX Placeholder.
58  * This calculations should be dynamically scaled by number of separate sc
59  * devices.  A base value of 'extra_history_size' should be defined for
60  * each syscons unit, and added and subtracted from the dynamic
61  * 'extra_history_size' as units are added and removed.  This way, each time
62  * a new syscons unit goes online, extra_history_size is automatically bumped.
63  */
64 #define	MAXSC	1
65 
66 #if !defined(SC_MAX_HISTORY_SIZE)
67 #define SC_MAX_HISTORY_SIZE	(1000 * MAXCONS * MAXSC)
68 #endif
69 
70 #if !defined(SC_HISTORY_SIZE)
71 #define SC_HISTORY_SIZE		(ROW * 4)
72 #endif
73 
74 #if (SC_HISTORY_SIZE * MAXCONS * MAXSC) > SC_MAX_HISTORY_SIZE
75 #undef SC_MAX_HISTORY_SIZE
76 #define SC_MAX_HISTORY_SIZE	(SC_HISTORY_SIZE * MAXCONS * MAXSC)
77 #endif
78 
79 /* local variables */
80 static int		extra_history_size
81 				= SC_MAX_HISTORY_SIZE - SC_HISTORY_SIZE*MAXCONS;
82 
83 /* local functions */
84 static void copy_history(sc_vtb_t *from, sc_vtb_t *to);
85 static void history_to_screen(scr_stat *scp);
86 
87 /* allocate a history buffer */
88 int
89 sc_alloc_history_buffer(scr_stat *scp, int lines, int prev_ysize, int wait)
90 {
91 	/*
92 	 * syscons unconditionally allocates buffers up to
93 	 * SC_HISTORY_SIZE lines or scp->ysize lines, whichever
94 	 * is larger. A value greater than that is allowed,
95 	 * subject to extra_history_size.
96 	 */
97 	sc_vtb_t *history;
98 	sc_vtb_t *prev_history;
99 	int cur_lines;				/* current buffer size */
100 	int min_lines;				/* guaranteed buffer size */
101 	int delta;				/* lines to put back */
102 
103 	if (lines <= 0)
104 		lines = SC_HISTORY_SIZE;	/* use the default value */
105 
106 	/* make it at least as large as the screen size */
107 	lines = imax(lines, scp->ysize);
108 
109 	/* remove the history buffer while we update it */
110 	history = prev_history = scp->history;
111 	scp->history = NULL;
112 
113 	/* calculate the amount of lines to put back to extra_history_size */
114 	delta = 0;
115 	if (prev_history) {
116 		cur_lines = sc_vtb_rows(history);
117 		min_lines = imax(SC_HISTORY_SIZE, prev_ysize);
118 		if (cur_lines > min_lines)
119 			delta = cur_lines - min_lines;
120 	}
121 
122 	/* lines up to min_lines are always allowed. */
123 	min_lines = imax(SC_HISTORY_SIZE, scp->ysize);
124 	if (lines > min_lines) {
125 		if (lines - min_lines > extra_history_size + delta) {
126 			/* too many lines are requested */
127 			scp->history = prev_history;
128 			return EINVAL;
129 		}
130 	}
131 
132 	/* allocate a new buffer */
133 	history = (sc_vtb_t *)malloc(sizeof(*history),
134 				     M_DEVBUF,
135 				     (wait) ? M_WAITOK : M_NOWAIT);
136 	if (history != NULL) {
137 		if (lines > min_lines)
138 			extra_history_size -= lines - min_lines;
139 		/* XXX error check? */
140 		sc_vtb_init(history, VTB_RINGBUFFER, scp->xsize, lines,
141 			    NULL, wait);
142 		/* FIXME: XXX no good? */
143 		sc_vtb_clear(history, scp->sc->scr_map[0x20],
144 			     SC_NORM_ATTR << 8);
145 		if (prev_history != NULL)
146 			copy_history(prev_history, history);
147 		scp->history_pos = sc_vtb_tail(history);
148 	} else {
149 		scp->history_pos = 0;
150 	}
151 
152 	/* destroy the previous buffer */
153 	if (prev_history != NULL) {
154 		extra_history_size += delta;
155 		sc_vtb_destroy(prev_history);
156 		free(prev_history, M_DEVBUF);
157 	}
158 
159 	scp->history = history;
160 
161 	return 0;
162 }
163 
164 static void
165 copy_history(sc_vtb_t *from, sc_vtb_t *to)
166 {
167 	int lines;
168 	int cols;
169 	int cols1;
170 	int cols2;
171 	int pos;
172 	int i;
173 
174 	lines = sc_vtb_rows(from);
175 	cols1 = sc_vtb_cols(from);
176 	cols2 = sc_vtb_cols(to);
177 	cols = imin(cols1, cols2);
178 	pos = sc_vtb_tail(from);
179 	for (i = 0; i < lines; ++i) {
180 		sc_vtb_append(from, pos, to, cols);
181 		if (cols < cols2)
182 			sc_vtb_seek(to, sc_vtb_pos(to,
183 						   sc_vtb_tail(to),
184 						   cols2 - cols));
185 		pos = sc_vtb_pos(from, pos, cols1);
186 	}
187 }
188 
189 void
190 sc_free_history_buffer(scr_stat *scp, int prev_ysize)
191 {
192 	sc_vtb_t *history;
193 	int cur_lines;				/* current buffer size */
194 	int min_lines;				/* guaranteed buffer size */
195 
196 	history = scp->history;
197 	scp->history = NULL;
198 	if (history == NULL)
199 		return;
200 
201 	cur_lines = sc_vtb_rows(history);
202 	min_lines = imax(SC_HISTORY_SIZE, prev_ysize);
203 	extra_history_size += (cur_lines > min_lines) ?
204 				  cur_lines - min_lines : 0;
205 
206 	sc_vtb_destroy(history);
207 	free(history, M_DEVBUF);
208 }
209 
210 /* copy entire screen into the top of the history buffer */
211 void
212 sc_hist_save(scr_stat *scp)
213 {
214 	sc_vtb_append(&scp->vtb, 0, scp->history, scp->xsize*scp->ysize);
215 	scp->history_pos = sc_vtb_tail(scp->history);
216 }
217 
218 /* restore the screen by copying from the history buffer */
219 int
220 sc_hist_restore(scr_stat *scp)
221 {
222 	int ret;
223 
224 	if (scp->history_pos != sc_vtb_tail(scp->history)) {
225 		scp->history_pos = sc_vtb_tail(scp->history);
226 		history_to_screen(scp);
227 		ret =  0;
228 	} else {
229 		ret = 1;
230 	}
231 	sc_vtb_seek(scp->history, sc_vtb_pos(scp->history,
232 					     sc_vtb_tail(scp->history),
233 					     -scp->xsize*scp->ysize));
234 	return ret;
235 }
236 
237 /* copy screen-full of saved lines */
238 static void
239 history_to_screen(scr_stat *scp)
240 {
241 	int pos;
242 	int i;
243 
244 	pos = scp->history_pos;
245 	for (i = 1; i <= scp->ysize; ++i) {
246 		pos = sc_vtb_pos(scp->history, pos, -scp->xsize);
247 		sc_vtb_copy(scp->history, pos,
248 			    &scp->vtb, scp->xsize*(scp->ysize - i),
249 			    scp->xsize);
250 	}
251 	mark_all(scp);
252 }
253 
254 /* go to the tail of the history buffer */
255 void
256 sc_hist_home(scr_stat *scp)
257 {
258 	scp->history_pos = sc_vtb_tail(scp->history);
259 	history_to_screen(scp);
260 }
261 
262 /* go to the top of the history buffer */
263 void
264 sc_hist_end(scr_stat *scp)
265 {
266 	scp->history_pos = sc_vtb_pos(scp->history, sc_vtb_tail(scp->history),
267 				      scp->xsize*scp->ysize);
268 	history_to_screen(scp);
269 }
270 
271 /* move one line up */
272 int
273 sc_hist_up_line(scr_stat *scp)
274 {
275 	if (sc_vtb_pos(scp->history, scp->history_pos, -(scp->xsize*scp->ysize))
276 	    == sc_vtb_tail(scp->history))
277 		return -1;
278 	scp->history_pos = sc_vtb_pos(scp->history, scp->history_pos,
279 				      -scp->xsize);
280 	history_to_screen(scp);
281 	return 0;
282 }
283 
284 /* move one line down */
285 int
286 sc_hist_down_line(scr_stat *scp)
287 {
288 	if (scp->history_pos == sc_vtb_tail(scp->history))
289 		return -1;
290 	scp->history_pos = sc_vtb_pos(scp->history, scp->history_pos,
291 				      scp->xsize);
292 	history_to_screen(scp);
293 	return 0;
294 }
295 
296 int
297 sc_hist_ioctl(struct tty *tp, u_long cmd, caddr_t data, struct thread *td)
298 {
299 	scr_stat *scp;
300 	int error;
301 
302 	switch (cmd) {
303 
304 	case CONS_HISTORY:  	/* set history size */
305 		scp = SC_STAT(tp);
306 		if (*(int *)data <= 0)
307 			return EINVAL;
308 		if (scp->status & BUFFER_SAVED)
309 			return EBUSY;
310 		DPRINTF(5, ("lines:%d, ysize:%d, pool:%d\n",
311 			    *(int *)data, scp->ysize, extra_history_size));
312 		error = sc_alloc_history_buffer(scp,
313 					       imax(*(int *)data, scp->ysize),
314 					       scp->ysize, TRUE);
315 		DPRINTF(5, ("error:%d, rows:%d, pool:%d\n", error,
316 			    sc_vtb_rows(scp->history), extra_history_size));
317 		return error;
318 
319 	case CONS_CLRHIST:
320 		scp = SC_STAT(tp);
321 		sc_vtb_clear(scp->history, scp->sc->scr_map[0x20],
322 		    SC_NORM_ATTR << 8);
323 		return 0;
324 	}
325 
326 	return ENOIOCTL;
327 }
328 
329 #endif /* SC_NO_HISTORY */
330