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 S��ren 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 */
80static int		extra_history_size
81				= SC_MAX_HISTORY_SIZE - SC_HISTORY_SIZE*MAXCONS;
82
83/* local functions */
84static void copy_history(sc_vtb_t *from, sc_vtb_t *to);
85static void history_to_screen(scr_stat *scp);
86
87/* allocate a history buffer */
88int
89sc_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
164static void
165copy_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
189void
190sc_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 */
211void
212sc_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 */
219int
220sc_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 */
238static void
239history_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 */
255void
256sc_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 */
263void
264sc_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 */
272int
273sc_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 */
285int
286sc_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
296int
297sc_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