xref: /openbmc/linux/drivers/tty/vt/consolemap.c (revision 139f39be42fcd5f88366d6f3e6f05002027d3514)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * consolemap.c
4  *
5  * Mapping from internal code (such as Latin-1 or Unicode or IBM PC code)
6  * to font positions.
7  *
8  * aeb, 950210
9  *
10  * Support for multiple unimaps by Jakub Jelinek <jj@ultra.linux.cz>, July 1998
11  *
12  * Fix bug in inverse translation. Stanislav Voronyi <stas@cnti.uanet.kharkov.ua>, Dec 1998
13  *
14  * In order to prevent the following circular lock dependency:
15  *   &mm->mmap_lock --> cpu_hotplug.lock --> console_lock --> &mm->mmap_lock
16  *
17  * We cannot allow page fault to happen while holding the console_lock.
18  * Therefore, all the userspace copy operations have to be done outside
19  * the console_lock critical sections.
20  *
21  * As all the affected functions are all called directly from vt_ioctl(), we
22  * can allocate some small buffers directly on stack without worrying about
23  * stack overflow.
24  */
25 
26 #include <linux/module.h>
27 #include <linux/kd.h>
28 #include <linux/errno.h>
29 #include <linux/mm.h>
30 #include <linux/slab.h>
31 #include <linux/init.h>
32 #include <linux/tty.h>
33 #include <linux/uaccess.h>
34 #include <linux/console.h>
35 #include <linux/consolemap.h>
36 #include <linux/vt_kern.h>
37 #include <linux/string.h>
38 
39 static unsigned short translations[][256] = {
40   /* 8-bit Latin-1 mapped to Unicode -- trivial mapping */
41   [LAT1_MAP] = {
42     0x0000, 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0007,
43     0x0008, 0x0009, 0x000a, 0x000b, 0x000c, 0x000d, 0x000e, 0x000f,
44     0x0010, 0x0011, 0x0012, 0x0013, 0x0014, 0x0015, 0x0016, 0x0017,
45     0x0018, 0x0019, 0x001a, 0x001b, 0x001c, 0x001d, 0x001e, 0x001f,
46     0x0020, 0x0021, 0x0022, 0x0023, 0x0024, 0x0025, 0x0026, 0x0027,
47     0x0028, 0x0029, 0x002a, 0x002b, 0x002c, 0x002d, 0x002e, 0x002f,
48     0x0030, 0x0031, 0x0032, 0x0033, 0x0034, 0x0035, 0x0036, 0x0037,
49     0x0038, 0x0039, 0x003a, 0x003b, 0x003c, 0x003d, 0x003e, 0x003f,
50     0x0040, 0x0041, 0x0042, 0x0043, 0x0044, 0x0045, 0x0046, 0x0047,
51     0x0048, 0x0049, 0x004a, 0x004b, 0x004c, 0x004d, 0x004e, 0x004f,
52     0x0050, 0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056, 0x0057,
53     0x0058, 0x0059, 0x005a, 0x005b, 0x005c, 0x005d, 0x005e, 0x005f,
54     0x0060, 0x0061, 0x0062, 0x0063, 0x0064, 0x0065, 0x0066, 0x0067,
55     0x0068, 0x0069, 0x006a, 0x006b, 0x006c, 0x006d, 0x006e, 0x006f,
56     0x0070, 0x0071, 0x0072, 0x0073, 0x0074, 0x0075, 0x0076, 0x0077,
57     0x0078, 0x0079, 0x007a, 0x007b, 0x007c, 0x007d, 0x007e, 0x007f,
58     0x0080, 0x0081, 0x0082, 0x0083, 0x0084, 0x0085, 0x0086, 0x0087,
59     0x0088, 0x0089, 0x008a, 0x008b, 0x008c, 0x008d, 0x008e, 0x008f,
60     0x0090, 0x0091, 0x0092, 0x0093, 0x0094, 0x0095, 0x0096, 0x0097,
61     0x0098, 0x0099, 0x009a, 0x009b, 0x009c, 0x009d, 0x009e, 0x009f,
62     0x00a0, 0x00a1, 0x00a2, 0x00a3, 0x00a4, 0x00a5, 0x00a6, 0x00a7,
63     0x00a8, 0x00a9, 0x00aa, 0x00ab, 0x00ac, 0x00ad, 0x00ae, 0x00af,
64     0x00b0, 0x00b1, 0x00b2, 0x00b3, 0x00b4, 0x00b5, 0x00b6, 0x00b7,
65     0x00b8, 0x00b9, 0x00ba, 0x00bb, 0x00bc, 0x00bd, 0x00be, 0x00bf,
66     0x00c0, 0x00c1, 0x00c2, 0x00c3, 0x00c4, 0x00c5, 0x00c6, 0x00c7,
67     0x00c8, 0x00c9, 0x00ca, 0x00cb, 0x00cc, 0x00cd, 0x00ce, 0x00cf,
68     0x00d0, 0x00d1, 0x00d2, 0x00d3, 0x00d4, 0x00d5, 0x00d6, 0x00d7,
69     0x00d8, 0x00d9, 0x00da, 0x00db, 0x00dc, 0x00dd, 0x00de, 0x00df,
70     0x00e0, 0x00e1, 0x00e2, 0x00e3, 0x00e4, 0x00e5, 0x00e6, 0x00e7,
71     0x00e8, 0x00e9, 0x00ea, 0x00eb, 0x00ec, 0x00ed, 0x00ee, 0x00ef,
72     0x00f0, 0x00f1, 0x00f2, 0x00f3, 0x00f4, 0x00f5, 0x00f6, 0x00f7,
73     0x00f8, 0x00f9, 0x00fa, 0x00fb, 0x00fc, 0x00fd, 0x00fe, 0x00ff
74   },
75   /* VT100 graphics mapped to Unicode */
76   [GRAF_MAP] = {
77     0x0000, 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0007,
78     0x0008, 0x0009, 0x000a, 0x000b, 0x000c, 0x000d, 0x000e, 0x000f,
79     0x0010, 0x0011, 0x0012, 0x0013, 0x0014, 0x0015, 0x0016, 0x0017,
80     0x0018, 0x0019, 0x001a, 0x001b, 0x001c, 0x001d, 0x001e, 0x001f,
81     0x0020, 0x0021, 0x0022, 0x0023, 0x0024, 0x0025, 0x0026, 0x0027,
82     0x0028, 0x0029, 0x002a, 0x2192, 0x2190, 0x2191, 0x2193, 0x002f,
83     0x2588, 0x0031, 0x0032, 0x0033, 0x0034, 0x0035, 0x0036, 0x0037,
84     0x0038, 0x0039, 0x003a, 0x003b, 0x003c, 0x003d, 0x003e, 0x003f,
85     0x0040, 0x0041, 0x0042, 0x0043, 0x0044, 0x0045, 0x0046, 0x0047,
86     0x0048, 0x0049, 0x004a, 0x004b, 0x004c, 0x004d, 0x004e, 0x004f,
87     0x0050, 0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056, 0x0057,
88     0x0058, 0x0059, 0x005a, 0x005b, 0x005c, 0x005d, 0x005e, 0x00a0,
89     0x25c6, 0x2592, 0x2409, 0x240c, 0x240d, 0x240a, 0x00b0, 0x00b1,
90     0x2591, 0x240b, 0x2518, 0x2510, 0x250c, 0x2514, 0x253c, 0x23ba,
91     0x23bb, 0x2500, 0x23bc, 0x23bd, 0x251c, 0x2524, 0x2534, 0x252c,
92     0x2502, 0x2264, 0x2265, 0x03c0, 0x2260, 0x00a3, 0x00b7, 0x007f,
93     0x0080, 0x0081, 0x0082, 0x0083, 0x0084, 0x0085, 0x0086, 0x0087,
94     0x0088, 0x0089, 0x008a, 0x008b, 0x008c, 0x008d, 0x008e, 0x008f,
95     0x0090, 0x0091, 0x0092, 0x0093, 0x0094, 0x0095, 0x0096, 0x0097,
96     0x0098, 0x0099, 0x009a, 0x009b, 0x009c, 0x009d, 0x009e, 0x009f,
97     0x00a0, 0x00a1, 0x00a2, 0x00a3, 0x00a4, 0x00a5, 0x00a6, 0x00a7,
98     0x00a8, 0x00a9, 0x00aa, 0x00ab, 0x00ac, 0x00ad, 0x00ae, 0x00af,
99     0x00b0, 0x00b1, 0x00b2, 0x00b3, 0x00b4, 0x00b5, 0x00b6, 0x00b7,
100     0x00b8, 0x00b9, 0x00ba, 0x00bb, 0x00bc, 0x00bd, 0x00be, 0x00bf,
101     0x00c0, 0x00c1, 0x00c2, 0x00c3, 0x00c4, 0x00c5, 0x00c6, 0x00c7,
102     0x00c8, 0x00c9, 0x00ca, 0x00cb, 0x00cc, 0x00cd, 0x00ce, 0x00cf,
103     0x00d0, 0x00d1, 0x00d2, 0x00d3, 0x00d4, 0x00d5, 0x00d6, 0x00d7,
104     0x00d8, 0x00d9, 0x00da, 0x00db, 0x00dc, 0x00dd, 0x00de, 0x00df,
105     0x00e0, 0x00e1, 0x00e2, 0x00e3, 0x00e4, 0x00e5, 0x00e6, 0x00e7,
106     0x00e8, 0x00e9, 0x00ea, 0x00eb, 0x00ec, 0x00ed, 0x00ee, 0x00ef,
107     0x00f0, 0x00f1, 0x00f2, 0x00f3, 0x00f4, 0x00f5, 0x00f6, 0x00f7,
108     0x00f8, 0x00f9, 0x00fa, 0x00fb, 0x00fc, 0x00fd, 0x00fe, 0x00ff
109   },
110   /* IBM Codepage 437 mapped to Unicode */
111   [IBMPC_MAP] = {
112     0x0000, 0x263a, 0x263b, 0x2665, 0x2666, 0x2663, 0x2660, 0x2022,
113     0x25d8, 0x25cb, 0x25d9, 0x2642, 0x2640, 0x266a, 0x266b, 0x263c,
114     0x25b6, 0x25c0, 0x2195, 0x203c, 0x00b6, 0x00a7, 0x25ac, 0x21a8,
115     0x2191, 0x2193, 0x2192, 0x2190, 0x221f, 0x2194, 0x25b2, 0x25bc,
116     0x0020, 0x0021, 0x0022, 0x0023, 0x0024, 0x0025, 0x0026, 0x0027,
117     0x0028, 0x0029, 0x002a, 0x002b, 0x002c, 0x002d, 0x002e, 0x002f,
118     0x0030, 0x0031, 0x0032, 0x0033, 0x0034, 0x0035, 0x0036, 0x0037,
119     0x0038, 0x0039, 0x003a, 0x003b, 0x003c, 0x003d, 0x003e, 0x003f,
120     0x0040, 0x0041, 0x0042, 0x0043, 0x0044, 0x0045, 0x0046, 0x0047,
121     0x0048, 0x0049, 0x004a, 0x004b, 0x004c, 0x004d, 0x004e, 0x004f,
122     0x0050, 0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056, 0x0057,
123     0x0058, 0x0059, 0x005a, 0x005b, 0x005c, 0x005d, 0x005e, 0x005f,
124     0x0060, 0x0061, 0x0062, 0x0063, 0x0064, 0x0065, 0x0066, 0x0067,
125     0x0068, 0x0069, 0x006a, 0x006b, 0x006c, 0x006d, 0x006e, 0x006f,
126     0x0070, 0x0071, 0x0072, 0x0073, 0x0074, 0x0075, 0x0076, 0x0077,
127     0x0078, 0x0079, 0x007a, 0x007b, 0x007c, 0x007d, 0x007e, 0x2302,
128     0x00c7, 0x00fc, 0x00e9, 0x00e2, 0x00e4, 0x00e0, 0x00e5, 0x00e7,
129     0x00ea, 0x00eb, 0x00e8, 0x00ef, 0x00ee, 0x00ec, 0x00c4, 0x00c5,
130     0x00c9, 0x00e6, 0x00c6, 0x00f4, 0x00f6, 0x00f2, 0x00fb, 0x00f9,
131     0x00ff, 0x00d6, 0x00dc, 0x00a2, 0x00a3, 0x00a5, 0x20a7, 0x0192,
132     0x00e1, 0x00ed, 0x00f3, 0x00fa, 0x00f1, 0x00d1, 0x00aa, 0x00ba,
133     0x00bf, 0x2310, 0x00ac, 0x00bd, 0x00bc, 0x00a1, 0x00ab, 0x00bb,
134     0x2591, 0x2592, 0x2593, 0x2502, 0x2524, 0x2561, 0x2562, 0x2556,
135     0x2555, 0x2563, 0x2551, 0x2557, 0x255d, 0x255c, 0x255b, 0x2510,
136     0x2514, 0x2534, 0x252c, 0x251c, 0x2500, 0x253c, 0x255e, 0x255f,
137     0x255a, 0x2554, 0x2569, 0x2566, 0x2560, 0x2550, 0x256c, 0x2567,
138     0x2568, 0x2564, 0x2565, 0x2559, 0x2558, 0x2552, 0x2553, 0x256b,
139     0x256a, 0x2518, 0x250c, 0x2588, 0x2584, 0x258c, 0x2590, 0x2580,
140     0x03b1, 0x00df, 0x0393, 0x03c0, 0x03a3, 0x03c3, 0x00b5, 0x03c4,
141     0x03a6, 0x0398, 0x03a9, 0x03b4, 0x221e, 0x03c6, 0x03b5, 0x2229,
142     0x2261, 0x00b1, 0x2265, 0x2264, 0x2320, 0x2321, 0x00f7, 0x2248,
143     0x00b0, 0x2219, 0x00b7, 0x221a, 0x207f, 0x00b2, 0x25a0, 0x00a0
144   },
145   /* User mapping -- default to codes for direct font mapping */
146   [USER_MAP] = {
147     0xf000, 0xf001, 0xf002, 0xf003, 0xf004, 0xf005, 0xf006, 0xf007,
148     0xf008, 0xf009, 0xf00a, 0xf00b, 0xf00c, 0xf00d, 0xf00e, 0xf00f,
149     0xf010, 0xf011, 0xf012, 0xf013, 0xf014, 0xf015, 0xf016, 0xf017,
150     0xf018, 0xf019, 0xf01a, 0xf01b, 0xf01c, 0xf01d, 0xf01e, 0xf01f,
151     0xf020, 0xf021, 0xf022, 0xf023, 0xf024, 0xf025, 0xf026, 0xf027,
152     0xf028, 0xf029, 0xf02a, 0xf02b, 0xf02c, 0xf02d, 0xf02e, 0xf02f,
153     0xf030, 0xf031, 0xf032, 0xf033, 0xf034, 0xf035, 0xf036, 0xf037,
154     0xf038, 0xf039, 0xf03a, 0xf03b, 0xf03c, 0xf03d, 0xf03e, 0xf03f,
155     0xf040, 0xf041, 0xf042, 0xf043, 0xf044, 0xf045, 0xf046, 0xf047,
156     0xf048, 0xf049, 0xf04a, 0xf04b, 0xf04c, 0xf04d, 0xf04e, 0xf04f,
157     0xf050, 0xf051, 0xf052, 0xf053, 0xf054, 0xf055, 0xf056, 0xf057,
158     0xf058, 0xf059, 0xf05a, 0xf05b, 0xf05c, 0xf05d, 0xf05e, 0xf05f,
159     0xf060, 0xf061, 0xf062, 0xf063, 0xf064, 0xf065, 0xf066, 0xf067,
160     0xf068, 0xf069, 0xf06a, 0xf06b, 0xf06c, 0xf06d, 0xf06e, 0xf06f,
161     0xf070, 0xf071, 0xf072, 0xf073, 0xf074, 0xf075, 0xf076, 0xf077,
162     0xf078, 0xf079, 0xf07a, 0xf07b, 0xf07c, 0xf07d, 0xf07e, 0xf07f,
163     0xf080, 0xf081, 0xf082, 0xf083, 0xf084, 0xf085, 0xf086, 0xf087,
164     0xf088, 0xf089, 0xf08a, 0xf08b, 0xf08c, 0xf08d, 0xf08e, 0xf08f,
165     0xf090, 0xf091, 0xf092, 0xf093, 0xf094, 0xf095, 0xf096, 0xf097,
166     0xf098, 0xf099, 0xf09a, 0xf09b, 0xf09c, 0xf09d, 0xf09e, 0xf09f,
167     0xf0a0, 0xf0a1, 0xf0a2, 0xf0a3, 0xf0a4, 0xf0a5, 0xf0a6, 0xf0a7,
168     0xf0a8, 0xf0a9, 0xf0aa, 0xf0ab, 0xf0ac, 0xf0ad, 0xf0ae, 0xf0af,
169     0xf0b0, 0xf0b1, 0xf0b2, 0xf0b3, 0xf0b4, 0xf0b5, 0xf0b6, 0xf0b7,
170     0xf0b8, 0xf0b9, 0xf0ba, 0xf0bb, 0xf0bc, 0xf0bd, 0xf0be, 0xf0bf,
171     0xf0c0, 0xf0c1, 0xf0c2, 0xf0c3, 0xf0c4, 0xf0c5, 0xf0c6, 0xf0c7,
172     0xf0c8, 0xf0c9, 0xf0ca, 0xf0cb, 0xf0cc, 0xf0cd, 0xf0ce, 0xf0cf,
173     0xf0d0, 0xf0d1, 0xf0d2, 0xf0d3, 0xf0d4, 0xf0d5, 0xf0d6, 0xf0d7,
174     0xf0d8, 0xf0d9, 0xf0da, 0xf0db, 0xf0dc, 0xf0dd, 0xf0de, 0xf0df,
175     0xf0e0, 0xf0e1, 0xf0e2, 0xf0e3, 0xf0e4, 0xf0e5, 0xf0e6, 0xf0e7,
176     0xf0e8, 0xf0e9, 0xf0ea, 0xf0eb, 0xf0ec, 0xf0ed, 0xf0ee, 0xf0ef,
177     0xf0f0, 0xf0f1, 0xf0f2, 0xf0f3, 0xf0f4, 0xf0f5, 0xf0f6, 0xf0f7,
178     0xf0f8, 0xf0f9, 0xf0fa, 0xf0fb, 0xf0fc, 0xf0fd, 0xf0fe, 0xf0ff
179   }
180 };
181 
182 /* The standard kernel character-to-font mappings are not invertible
183    -- this is just a best effort. */
184 
185 #define MAX_GLYPH 512		/* Max possible glyph value */
186 
187 static enum translation_map inv_translate[MAX_NR_CONSOLES];
188 
189 #define UNI_DIRS	32U
190 #define UNI_DIR_ROWS	32U
191 #define UNI_ROW_GLYPHS	64U
192 
193 #define UNI_DIR(uni)		( (uni)                   >> 11)
194 #define UNI_ROW(uni)		(((uni) & GENMASK(10, 6)) >>  6)
195 #define UNI_GLYPH(uni)		( (uni) & GENMASK( 5, 0))
196 #define UNI(dir, row, glyph)	(((dir) << 11) | ((row) << 6) | (glyph))
197 
198 /**
199  * struct uni_pagedict -- unicode directory
200  *
201  * @uni_pgdir: 32*32*64 table with glyphs
202  * @refcount: reference count of this structure
203  * @sum: checksum
204  * @inverse_translations: best-effort inverse mapping
205  * @inverse_trans_unicode: best-effort inverse mapping to unicode
206  */
207 struct uni_pagedict {
208 	u16		**uni_pgdir[UNI_DIRS];
209 	unsigned long	refcount;
210 	unsigned long	sum;
211 	unsigned char	*inverse_translations[LAST_MAP + 1];
212 	u16		*inverse_trans_unicode;
213 };
214 
215 static struct uni_pagedict *dflt;
216 
217 static void set_inverse_transl(struct vc_data *conp, struct uni_pagedict *p,
218 	       enum translation_map m)
219 {
220 	int j, glyph;
221 	unsigned short *t = translations[m];
222 	unsigned char *q;
223 
224 	if (!p)
225 		return;
226 	q = p->inverse_translations[m];
227 
228 	if (!q) {
229 		q = p->inverse_translations[m] = kmalloc(MAX_GLYPH, GFP_KERNEL);
230 		if (!q)
231 			return;
232 	}
233 	memset(q, 0, MAX_GLYPH);
234 
235 	for (j = 0; j < ARRAY_SIZE(translations[m]); j++) {
236 		glyph = conv_uni_to_pc(conp, t[j]);
237 		if (glyph >= 0 && glyph < MAX_GLYPH && q[glyph] < 32) {
238 			/* prefer '-' above SHY etc. */
239 			q[glyph] = j;
240 		}
241 	}
242 }
243 
244 static void set_inverse_trans_unicode(struct vc_data *conp,
245 				      struct uni_pagedict *p)
246 {
247 	unsigned int d, r, g;
248 	u16 *inv;
249 
250 	if (!p)
251 		return;
252 
253 	inv = p->inverse_trans_unicode;
254 	if (!inv) {
255 		inv = p->inverse_trans_unicode = kmalloc_array(MAX_GLYPH,
256 				sizeof(*inv), GFP_KERNEL);
257 		if (!inv)
258 			return;
259 	}
260 	memset(inv, 0, MAX_GLYPH * sizeof(*inv));
261 
262 	for (d = 0; d < UNI_DIRS; d++) {
263 		u16 **dir = p->uni_pgdir[d];
264 		if (!dir)
265 			continue;
266 		for (r = 0; r < UNI_DIR_ROWS; r++) {
267 			u16 *row = dir[r];
268 			if (!row)
269 				continue;
270 			for (g = 0; g < UNI_ROW_GLYPHS; g++) {
271 				u16 glyph = row[g];
272 				if (glyph < MAX_GLYPH && inv[glyph] < 32)
273 					inv[glyph] = UNI(d, r, g);
274 			}
275 		}
276 	}
277 }
278 
279 unsigned short *set_translate(enum translation_map m, struct vc_data *vc)
280 {
281 	inv_translate[vc->vc_num] = m;
282 	return translations[m];
283 }
284 
285 /*
286  * Inverse translation is impossible for several reasons:
287  * 1. The font<->character maps are not 1-1.
288  * 2. The text may have been written while a different translation map
289  *    was active.
290  * Still, it is now possible to a certain extent to cut and paste non-ASCII.
291  */
292 u16 inverse_translate(const struct vc_data *conp, u16 glyph, bool use_unicode)
293 {
294 	struct uni_pagedict *p;
295 	enum translation_map m;
296 
297 	if (glyph >= MAX_GLYPH)
298 		return 0;
299 
300 	p = *conp->vc_uni_pagedir_loc;
301 	if (!p)
302 		return glyph;
303 
304 	if (use_unicode) {
305 		if (!p->inverse_trans_unicode)
306 			return glyph;
307 
308 		return p->inverse_trans_unicode[glyph];
309 	}
310 
311 	m = inv_translate[conp->vc_num];
312 	if (!p->inverse_translations[m])
313 		return glyph;
314 
315 	return p->inverse_translations[m][glyph];
316 }
317 EXPORT_SYMBOL_GPL(inverse_translate);
318 
319 static void update_user_maps(void)
320 {
321 	int i;
322 	struct uni_pagedict *p, *q = NULL;
323 
324 	for (i = 0; i < MAX_NR_CONSOLES; i++) {
325 		if (!vc_cons_allocated(i))
326 			continue;
327 		p = *vc_cons[i].d->vc_uni_pagedir_loc;
328 		if (p && p != q) {
329 			set_inverse_transl(vc_cons[i].d, p, USER_MAP);
330 			set_inverse_trans_unicode(vc_cons[i].d, p);
331 			q = p;
332 		}
333 	}
334 }
335 
336 /*
337  * Load customizable translation table
338  * arg points to a 256 byte translation table.
339  *
340  * The "old" variants are for translation directly to font (using the
341  * 0xf000-0xf0ff "transparent" Unicodes) whereas the "new" variants set
342  * Unicodes explicitly.
343  */
344 int con_set_trans_old(unsigned char __user * arg)
345 {
346 	unsigned short inbuf[E_TABSZ];
347 	unsigned int i;
348 	unsigned char ch;
349 
350 	for (i = 0; i < ARRAY_SIZE(inbuf); i++) {
351 		if (get_user(ch, &arg[i]))
352 			return -EFAULT;
353 		inbuf[i] = UNI_DIRECT_BASE | ch;
354 	}
355 
356 	console_lock();
357 	memcpy(translations[USER_MAP], inbuf, sizeof(inbuf));
358 	update_user_maps();
359 	console_unlock();
360 	return 0;
361 }
362 
363 int con_get_trans_old(unsigned char __user * arg)
364 {
365 	int i, ch;
366 	unsigned short *p = translations[USER_MAP];
367 	unsigned char outbuf[E_TABSZ];
368 
369 	console_lock();
370 	for (i = 0; i < ARRAY_SIZE(outbuf); i++)
371 	{
372 		ch = conv_uni_to_pc(vc_cons[fg_console].d, p[i]);
373 		outbuf[i] = (ch & ~0xff) ? 0 : ch;
374 	}
375 	console_unlock();
376 
377 	return copy_to_user(arg, outbuf, sizeof(outbuf)) ? -EFAULT : 0;
378 }
379 
380 int con_set_trans_new(ushort __user * arg)
381 {
382 	unsigned short inbuf[E_TABSZ];
383 
384 	if (copy_from_user(inbuf, arg, sizeof(inbuf)))
385 		return -EFAULT;
386 
387 	console_lock();
388 	memcpy(translations[USER_MAP], inbuf, sizeof(inbuf));
389 	update_user_maps();
390 	console_unlock();
391 	return 0;
392 }
393 
394 int con_get_trans_new(ushort __user * arg)
395 {
396 	unsigned short outbuf[E_TABSZ];
397 
398 	console_lock();
399 	memcpy(outbuf, translations[USER_MAP], sizeof(outbuf));
400 	console_unlock();
401 
402 	return copy_to_user(arg, outbuf, sizeof(outbuf)) ? -EFAULT : 0;
403 }
404 
405 /*
406  * Unicode -> current font conversion
407  *
408  * A font has at most 512 chars, usually 256.
409  * But one font position may represent several Unicode chars.
410  * A hashtable is somewhat of a pain to deal with, so use a
411  * "paged table" instead.  Simulation has shown the memory cost of
412  * this 3-level paged table scheme to be comparable to a hash table.
413  */
414 
415 extern u8 dfont_unicount[];	/* Defined in console_defmap.c */
416 extern u16 dfont_unitable[];
417 
418 static void con_release_unimap(struct uni_pagedict *dict)
419 {
420 	unsigned int d, r;
421 
422 	if (dict == dflt)
423 		dflt = NULL;
424 
425 	for (d = 0; d < UNI_DIRS; d++) {
426 		u16 **dir = dict->uni_pgdir[d];
427 		if (dir != NULL) {
428 			for (r = 0; r < UNI_DIR_ROWS; r++)
429 				kfree(dir[r]);
430 			kfree(dir);
431 		}
432 		dict->uni_pgdir[d] = NULL;
433 	}
434 
435 	for (r = 0; r < ARRAY_SIZE(dict->inverse_translations); r++) {
436 		kfree(dict->inverse_translations[r]);
437 		dict->inverse_translations[r] = NULL;
438 	}
439 
440 	kfree(dict->inverse_trans_unicode);
441 	dict->inverse_trans_unicode = NULL;
442 }
443 
444 /* Caller must hold the console lock */
445 void con_free_unimap(struct vc_data *vc)
446 {
447 	struct uni_pagedict *p;
448 
449 	p = *vc->vc_uni_pagedir_loc;
450 	if (!p)
451 		return;
452 	*vc->vc_uni_pagedir_loc = NULL;
453 	if (--p->refcount)
454 		return;
455 	con_release_unimap(p);
456 	kfree(p);
457 }
458 
459 static int con_unify_unimap(struct vc_data *conp, struct uni_pagedict *dict1)
460 {
461 	struct uni_pagedict *dict2;
462 	unsigned int cons, d, r;
463 
464 	for (cons = 0; cons < MAX_NR_CONSOLES; cons++) {
465 		if (!vc_cons_allocated(cons))
466 			continue;
467 		dict2 = *vc_cons[cons].d->vc_uni_pagedir_loc;
468 		if (!dict2 || dict2 == dict1 || dict2->sum != dict1->sum)
469 			continue;
470 		for (d = 0; d < UNI_DIRS; d++) {
471 			u16 **dir1 = dict1->uni_pgdir[d];
472 			u16 **dir2 = dict2->uni_pgdir[d];
473 			if (!dir1 && !dir2)
474 				continue;
475 			if (!dir1 || !dir2)
476 				break;
477 			for (r = 0; r < UNI_DIR_ROWS; r++) {
478 				if (!dir1[r] && !dir2[r])
479 					continue;
480 				if (!dir1[r] || !dir2[r])
481 					break;
482 				if (memcmp(dir1[r], dir2[r], UNI_ROW_GLYPHS *
483 							sizeof(*dir1[r])))
484 					break;
485 			}
486 			if (r < UNI_DIR_ROWS)
487 				break;
488 		}
489 		if (d == UNI_DIRS) {
490 			dict2->refcount++;
491 			*conp->vc_uni_pagedir_loc = dict2;
492 			con_release_unimap(dict1);
493 			kfree(dict1);
494 			return 1;
495 		}
496 	}
497 	return 0;
498 }
499 
500 static int
501 con_insert_unipair(struct uni_pagedict *p, u_short unicode, u_short fontpos)
502 {
503 	u16 **dir, *row;
504 	unsigned int n;
505 
506 	n = UNI_DIR(unicode);
507 	dir = p->uni_pgdir[n];
508 	if (!dir) {
509 		dir = p->uni_pgdir[n] = kcalloc(UNI_DIR_ROWS, sizeof(*dir),
510 				GFP_KERNEL);
511 		if (!dir)
512 			return -ENOMEM;
513 	}
514 
515 	n = UNI_ROW(unicode);
516 	row = dir[n];
517 	if (!row) {
518 		row = dir[n] = kmalloc_array(UNI_ROW_GLYPHS, sizeof(*row),
519 				GFP_KERNEL);
520 		if (!row)
521 			return -ENOMEM;
522 		/* No glyphs for the characters (yet) */
523 		memset(row, 0xff, UNI_ROW_GLYPHS * sizeof(*row));
524 	}
525 
526 	row[UNI_GLYPH(unicode)] = fontpos;
527 
528 	p->sum += (fontpos << 20U) + unicode;
529 
530 	return 0;
531 }
532 
533 static int con_allocate_new(struct vc_data *vc)
534 {
535 	struct uni_pagedict *new, *old = *vc->vc_uni_pagedir_loc;
536 
537 	new = kzalloc(sizeof(*new), GFP_KERNEL);
538 	if (!new)
539 		return -ENOMEM;
540 
541 	new->refcount = 1;
542 	*vc->vc_uni_pagedir_loc = new;
543 
544 	if (old)
545 		old->refcount--;
546 
547 	return 0;
548 }
549 
550 /* Caller must hold the lock */
551 static int con_do_clear_unimap(struct vc_data *vc)
552 {
553 	struct uni_pagedict *old = *vc->vc_uni_pagedir_loc;
554 
555 	if (!old || old->refcount > 1)
556 		return con_allocate_new(vc);
557 
558 	if (old == dflt)
559 		dflt = NULL;
560 	old->sum = 0;
561 	con_release_unimap(old);
562 
563 	return 0;
564 }
565 
566 int con_clear_unimap(struct vc_data *vc)
567 {
568 	int ret;
569 	console_lock();
570 	ret = con_do_clear_unimap(vc);
571 	console_unlock();
572 	return ret;
573 }
574 
575 static struct uni_pagedict *con_unshare_unimap(struct vc_data *vc,
576 		struct uni_pagedict *old)
577 {
578 	struct uni_pagedict *new;
579 	unsigned int d, r, g;
580 	int ret;
581 	u16 uni = 0;
582 
583 	ret = con_allocate_new(vc);
584 	if (ret)
585 		return ERR_PTR(ret);
586 
587 	new = *vc->vc_uni_pagedir_loc;
588 
589 	/*
590 	 * uni_pgdir is a 32*32*64 table with rows allocated when its first
591 	 * entry is added. The unicode value must still be incremented for
592 	 * empty rows. We are copying entries from "old" to "new".
593 	 */
594 	for (d = 0; d < UNI_DIRS; d++) {
595 		u16 **dir = old->uni_pgdir[d];
596 		if (!dir) {
597 			/* Account for empty table */
598 			uni += UNI_DIR_ROWS * UNI_ROW_GLYPHS;
599 			continue;
600 		}
601 
602 		for (r = 0; r < UNI_DIR_ROWS; r++) {
603 			u16 *row = dir[r];
604 			if (!row) {
605 				/* Account for row of 64 empty entries */
606 				uni += UNI_ROW_GLYPHS;
607 				continue;
608 			}
609 
610 			for (g = 0; g < UNI_ROW_GLYPHS; g++, uni++) {
611 				if (row[g] == 0xffff)
612 					continue;
613 				/*
614 				 * Found one, copy entry for unicode uni with
615 				 * fontpos value row[g].
616 				 */
617 				ret = con_insert_unipair(new, uni, row[g]);
618 				if (ret) {
619 					old->refcount++;
620 					*vc->vc_uni_pagedir_loc = old;
621 					con_release_unimap(new);
622 					kfree(new);
623 					return ERR_PTR(ret);
624 				}
625 			}
626 		}
627 	}
628 
629 	return new;
630 }
631 
632 int con_set_unimap(struct vc_data *vc, ushort ct, struct unipair __user *list)
633 {
634 	int err = 0, err1;
635 	struct uni_pagedict *dict;
636 	struct unipair *unilist, *plist;
637 
638 	if (!ct)
639 		return 0;
640 
641 	unilist = vmemdup_user(list, array_size(sizeof(*unilist), ct));
642 	if (IS_ERR(unilist))
643 		return PTR_ERR(unilist);
644 
645 	console_lock();
646 
647 	/* Save original vc_unipagdir_loc in case we allocate a new one */
648 	dict = *vc->vc_uni_pagedir_loc;
649 	if (!dict) {
650 		err = -EINVAL;
651 		goto out_unlock;
652 	}
653 
654 	if (dict->refcount > 1) {
655 		dict = con_unshare_unimap(vc, dict);
656 		if (IS_ERR(dict)) {
657 			err = PTR_ERR(dict);
658 			goto out_unlock;
659 		}
660 	} else if (dict == dflt) {
661 		dflt = NULL;
662 	}
663 
664 	/*
665 	 * Insert user specified unicode pairs into new table.
666 	 */
667 	for (plist = unilist; ct; ct--, plist++) {
668 		err1 = con_insert_unipair(dict, plist->unicode, plist->fontpos);
669 		if (err1)
670 			err = err1;
671 	}
672 
673 	/*
674 	 * Merge with fontmaps of any other virtual consoles.
675 	 */
676 	if (con_unify_unimap(vc, dict))
677 		goto out_unlock;
678 
679 	for (enum translation_map m = FIRST_MAP; m <= LAST_MAP; m++)
680 		set_inverse_transl(vc, dict, m);
681 	set_inverse_trans_unicode(vc, dict);
682 
683 out_unlock:
684 	console_unlock();
685 	kvfree(unilist);
686 	return err;
687 }
688 
689 /**
690  *	con_set_default_unimap	-	set default unicode map
691  *	@vc: the console we are updating
692  *
693  *	Loads the unimap for the hardware font, as defined in uni_hash.tbl.
694  *	The representation used was the most compact I could come up
695  *	with.  This routine is executed at video setup, and when the
696  *	PIO_FONTRESET ioctl is called.
697  *
698  *	The caller must hold the console lock
699  */
700 int con_set_default_unimap(struct vc_data *vc)
701 {
702 	struct uni_pagedict *dict;
703 	unsigned int fontpos, count;
704 	int err = 0, err1;
705 	u16 *dfont;
706 
707 	if (dflt) {
708 		dict = *vc->vc_uni_pagedir_loc;
709 		if (dict == dflt)
710 			return 0;
711 
712 		dflt->refcount++;
713 		*vc->vc_uni_pagedir_loc = dflt;
714 		if (dict && !--dict->refcount) {
715 			con_release_unimap(dict);
716 			kfree(dict);
717 		}
718 		return 0;
719 	}
720 
721 	/* The default font is always 256 characters */
722 
723 	err = con_do_clear_unimap(vc);
724 	if (err)
725 		return err;
726 
727 	dict = *vc->vc_uni_pagedir_loc;
728 	dfont = dfont_unitable;
729 
730 	for (fontpos = 0; fontpos < 256U; fontpos++)
731 		for (count = dfont_unicount[fontpos]; count; count--) {
732 			err1 = con_insert_unipair(dict, *(dfont++), fontpos);
733 			if (err1)
734 				err = err1;
735 		}
736 
737 	if (con_unify_unimap(vc, dict)) {
738 		dflt = *vc->vc_uni_pagedir_loc;
739 		return err;
740 	}
741 
742 	for (enum translation_map m = FIRST_MAP; m <= LAST_MAP; m++)
743 		set_inverse_transl(vc, dict, m);
744 	set_inverse_trans_unicode(vc, dict);
745 	dflt = dict;
746 	return err;
747 }
748 EXPORT_SYMBOL(con_set_default_unimap);
749 
750 /**
751  *	con_copy_unimap		-	copy unimap between two vts
752  *	@dst_vc: target
753  *	@src_vc: source
754  *
755  *	The caller must hold the console lock when invoking this method
756  */
757 int con_copy_unimap(struct vc_data *dst_vc, struct vc_data *src_vc)
758 {
759 	struct uni_pagedict *src;
760 
761 	if (!*src_vc->vc_uni_pagedir_loc)
762 		return -EINVAL;
763 	if (*dst_vc->vc_uni_pagedir_loc == *src_vc->vc_uni_pagedir_loc)
764 		return 0;
765 	con_free_unimap(dst_vc);
766 	src = *src_vc->vc_uni_pagedir_loc;
767 	src->refcount++;
768 	*dst_vc->vc_uni_pagedir_loc = src;
769 	return 0;
770 }
771 EXPORT_SYMBOL(con_copy_unimap);
772 
773 /*
774  *	con_get_unimap		-	get the unicode map
775  *
776  *	Read the console unicode data for this console. Called from the ioctl
777  *	handlers.
778  */
779 int con_get_unimap(struct vc_data *vc, ushort ct, ushort __user *uct,
780 		struct unipair __user *list)
781 {
782 	ushort ect;
783 	struct uni_pagedict *dict;
784 	struct unipair *unilist;
785 	unsigned int d, r, g;
786 	int ret = 0;
787 
788 	unilist = kvmalloc_array(ct, sizeof(*unilist), GFP_KERNEL);
789 	if (!unilist)
790 		return -ENOMEM;
791 
792 	console_lock();
793 
794 	ect = 0;
795 	dict = *vc->vc_uni_pagedir_loc;
796 	if (!dict)
797 		goto unlock;
798 
799 	for (d = 0; d < UNI_DIRS; d++) {
800 		u16 **dir = dict->uni_pgdir[d];
801 		if (!dir)
802 			continue;
803 
804 		for (r = 0; r < UNI_DIR_ROWS; r++) {
805 			u16 *row = dir[r];
806 			if (!row)
807 				continue;
808 
809 			for (g = 0; g < UNI_ROW_GLYPHS; g++, row++) {
810 				if (*row >= MAX_GLYPH)
811 					continue;
812 				if (ect < ct) {
813 					unilist[ect].unicode = UNI(d, r, g);
814 					unilist[ect].fontpos = *row;
815 				}
816 				ect++;
817 			}
818 		}
819 	}
820 unlock:
821 	console_unlock();
822 	if (copy_to_user(list, unilist, min(ect, ct) * sizeof(*unilist)))
823 		ret = -EFAULT;
824 	if (put_user(ect, uct))
825 		ret = -EFAULT;
826 	kvfree(unilist);
827 	return ret ? ret : (ect <= ct) ? 0 : -ENOMEM;
828 }
829 
830 /*
831  * Always use USER_MAP. These functions are used by the keyboard,
832  * which shouldn't be affected by G0/G1 switching, etc.
833  * If the user map still contains default values, i.e. the
834  * direct-to-font mapping, then assume user is using Latin1.
835  *
836  * FIXME: at some point we need to decide if we want to lock the table
837  * update element itself via the keyboard_event_lock for consistency with the
838  * keyboard driver as well as the consoles
839  */
840 /* may be called during an interrupt */
841 u32 conv_8bit_to_uni(unsigned char c)
842 {
843 	unsigned short uni = translations[USER_MAP][c];
844 	return uni == (0xf000 | c) ? c : uni;
845 }
846 
847 int conv_uni_to_8bit(u32 uni)
848 {
849 	int c;
850 	for (c = 0; c < ARRAY_SIZE(translations[USER_MAP]); c++)
851 		if (translations[USER_MAP][c] == uni ||
852 		   (translations[USER_MAP][c] == (c | 0xf000) && uni == c))
853 			return c;
854 	return -1;
855 }
856 
857 int conv_uni_to_pc(struct vc_data *conp, long ucs)
858 {
859 	struct uni_pagedict *dict;
860 	u16 **dir, *row, glyph;
861 
862 	/* Only 16-bit codes supported at this time */
863 	if (ucs > 0xffff)
864 		return -4;		/* Not found */
865 	else if (ucs < 0x20)
866 		return -1;		/* Not a printable character */
867 	else if (ucs == 0xfeff || (ucs >= 0x200b && ucs <= 0x200f))
868 		return -2;			/* Zero-width space */
869 	/*
870 	 * UNI_DIRECT_BASE indicates the start of the region in the User Zone
871 	 * which always has a 1:1 mapping to the currently loaded font.  The
872 	 * UNI_DIRECT_MASK indicates the bit span of the region.
873 	 */
874 	else if ((ucs & ~UNI_DIRECT_MASK) == UNI_DIRECT_BASE)
875 		return ucs & UNI_DIRECT_MASK;
876 
877 	dict = *conp->vc_uni_pagedir_loc;
878 	if (!dict)
879 		return -3;
880 
881 	dir = dict->uni_pgdir[UNI_DIR(ucs)];
882 	if (!dir)
883 		return -4;
884 
885 	row = dir[UNI_ROW(ucs)];
886 	if (!row)
887 		return -4;
888 
889 	glyph = row[UNI_GLYPH(ucs)];
890 	if (glyph >= MAX_GLYPH)
891 		return -4;
892 
893 	return glyph;
894 }
895 
896 /*
897  * This is called at sys_setup time, after memory and the console are
898  * initialized.  It must be possible to call kmalloc(..., GFP_KERNEL)
899  * from this function, hence the call from sys_setup.
900  */
901 void __init
902 console_map_init(void)
903 {
904 	int i;
905 
906 	for (i = 0; i < MAX_NR_CONSOLES; i++)
907 		if (vc_cons_allocated(i) && !*vc_cons[i].d->vc_uni_pagedir_loc)
908 			con_set_default_unimap(vc_cons[i].d);
909 }
910 
911