/*
 * consolemap.c
 *
 * Mapping from internal code (such as Latin-1 or Unicode or IBM PC code)
 * to font positions.
 *
 * aeb, 950210
 */

#include <linux/kd.h>
#include <linux/errno.h>
#include <linux/mm.h>
#include <linux/malloc.h>
#include <asm/segment.h>
#include "consolemap.h"

static unsigned short translations[][256] = {
  /* 8-bit Latin-1 mapped to Unicode -- trivial mapping */
  {
    0x0000, 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0007,
    0x0008, 0x0009, 0x000a, 0x000b, 0x000c, 0x000d, 0x000e, 0x000f,
    0x0010, 0x0011, 0x0012, 0x0013, 0x0014, 0x0015, 0x0016, 0x0017,
    0x0018, 0x0019, 0x001a, 0x001b, 0x001c, 0x001d, 0x001e, 0x001f,
    0x0020, 0x0021, 0x0022, 0x0023, 0x0024, 0x0025, 0x0026, 0x0027,
    0x0028, 0x0029, 0x002a, 0x002b, 0x002c, 0x002d, 0x002e, 0x002f,
    0x0030, 0x0031, 0x0032, 0x0033, 0x0034, 0x0035, 0x0036, 0x0037,
    0x0038, 0x0039, 0x003a, 0x003b, 0x003c, 0x003d, 0x003e, 0x003f,
    0x0040, 0x0041, 0x0042, 0x0043, 0x0044, 0x0045, 0x0046, 0x0047,
    0x0048, 0x0049, 0x004a, 0x004b, 0x004c, 0x004d, 0x004e, 0x004f,
    0x0050, 0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056, 0x0057,
    0x0058, 0x0059, 0x005a, 0x005b, 0x005c, 0x005d, 0x005e, 0x005f,
    0x0060, 0x0061, 0x0062, 0x0063, 0x0064, 0x0065, 0x0066, 0x0067,
    0x0068, 0x0069, 0x006a, 0x006b, 0x006c, 0x006d, 0x006e, 0x006f,
    0x0070, 0x0071, 0x0072, 0x0073, 0x0074, 0x0075, 0x0076, 0x0077,
    0x0078, 0x0079, 0x007a, 0x007b, 0x007c, 0x007d, 0x007e, 0x007f,
    0x0080, 0x0081, 0x0082, 0x0083, 0x0084, 0x0085, 0x0086, 0x0087,
    0x0088, 0x0089, 0x008a, 0x008b, 0x008c, 0x008d, 0x008e, 0x008f,
    0x0090, 0x0091, 0x0092, 0x0093, 0x0094, 0x0095, 0x0096, 0x0097,
    0x0098, 0x0099, 0x009a, 0x009b, 0x009c, 0x009d, 0x009e, 0x009f,
    0x00a0, 0x00a1, 0x00a2, 0x00a3, 0x00a4, 0x00a5, 0x00a6, 0x00a7,
    0x00a8, 0x00a9, 0x00aa, 0x00ab, 0x00ac, 0x00ad, 0x00ae, 0x00af,
    0x00b0, 0x00b1, 0x00b2, 0x00b3, 0x00b4, 0x00b5, 0x00b6, 0x00b7,
    0x00b8, 0x00b9, 0x00ba, 0x00bb, 0x00bc, 0x00bd, 0x00be, 0x00bf,
    0x00c0, 0x00c1, 0x00c2, 0x00c3, 0x00c4, 0x00c5, 0x00c6, 0x00c7,
    0x00c8, 0x00c9, 0x00ca, 0x00cb, 0x00cc, 0x00cd, 0x00ce, 0x00cf,
    0x00d0, 0x00d1, 0x00d2, 0x00d3, 0x00d4, 0x00d5, 0x00d6, 0x00d7,
    0x00d8, 0x00d9, 0x00da, 0x00db, 0x00dc, 0x00dd, 0x00de, 0x00df,
    0x00e0, 0x00e1, 0x00e2, 0x00e3, 0x00e4, 0x00e5, 0x00e6, 0x00e7,
    0x00e8, 0x00e9, 0x00ea, 0x00eb, 0x00ec, 0x00ed, 0x00ee, 0x00ef,
    0x00f0, 0x00f1, 0x00f2, 0x00f3, 0x00f4, 0x00f5, 0x00f6, 0x00f7,
    0x00f8, 0x00f9, 0x00fa, 0x00fb, 0x00fc, 0x00fd, 0x00fe, 0x00ff
  }, 
  /* VT100 graphics mapped to Unicode */
  {
    0x0000, 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0007,
    0x0008, 0x0009, 0x000a, 0x000b, 0x000c, 0x000d, 0x000e, 0x000f,
    0x0010, 0x0011, 0x0012, 0x0013, 0x0014, 0x0015, 0x0016, 0x0017,
    0x0018, 0x0019, 0x001a, 0x001b, 0x001c, 0x001d, 0x001e, 0x001f,
    0x0020, 0x0021, 0x0022, 0x0023, 0x0024, 0x0025, 0x0026, 0x0027,
    0x0028, 0x0029, 0x002a, 0x002b, 0x002c, 0x002d, 0x002e, 0x002f,
    0x0030, 0x0031, 0x0032, 0x0033, 0x0034, 0x0035, 0x0036, 0x0037,
    0x0038, 0x0039, 0x003a, 0x003b, 0x003c, 0x003d, 0x003e, 0x003f,
    0x0040, 0x0041, 0x0042, 0x0043, 0x0044, 0x0045, 0x0046, 0x0047,
    0x0048, 0x0049, 0x004a, 0x004b, 0x004c, 0x004d, 0x004e, 0x004f,
    0x0050, 0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056, 0x0057,
    0x0058, 0x0059, 0x005a, 0x005b, 0x005c, 0x005d, 0x005e, 0x00a0,
    0x25c6, 0x2592, 0x2409, 0x240c, 0x240d, 0x240a, 0x00b0, 0x00b1,
    0x2424, 0x240b, 0x2518, 0x2510, 0x250c, 0x2514, 0x253c, 0xf800,
    0xf801, 0x2500, 0xf803, 0xf804, 0x251c, 0x2524, 0x2534, 0x252c,
    0x2502, 0x2264, 0x2265, 0x03c0, 0x2260, 0x00a3, 0x00b7, 0x007f,
    0x0080, 0x0081, 0x0082, 0x0083, 0x0084, 0x0085, 0x0086, 0x0087,
    0x0088, 0x0089, 0x008a, 0x008b, 0x008c, 0x008d, 0x008e, 0x008f,
    0x0090, 0x0091, 0x0092, 0x0093, 0x0094, 0x0095, 0x0096, 0x0097,
    0x0098, 0x0099, 0x009a, 0x009b, 0x009c, 0x009d, 0x009e, 0x009f,
    0x00a0, 0x00a1, 0x00a2, 0x00a3, 0x00a4, 0x00a5, 0x00a6, 0x00a7,
    0x00a8, 0x00a9, 0x00aa, 0x00ab, 0x00ac, 0x00ad, 0x00ae, 0x00af,
    0x00b0, 0x00b1, 0x00b2, 0x00b3, 0x00b4, 0x00b5, 0x00b6, 0x00b7,
    0x00b8, 0x00b9, 0x00ba, 0x00bb, 0x00bc, 0x00bd, 0x00be, 0x00bf,
    0x00c0, 0x00c1, 0x00c2, 0x00c3, 0x00c4, 0x00c5, 0x00c6, 0x00c7,
    0x00c8, 0x00c9, 0x00ca, 0x00cb, 0x00cc, 0x00cd, 0x00ce, 0x00cf,
    0x00d0, 0x00d1, 0x00d2, 0x00d3, 0x00d4, 0x00d5, 0x00d6, 0x00d7,
    0x00d8, 0x00d9, 0x00da, 0x00db, 0x00dc, 0x00dd, 0x00de, 0x00df,
    0x00e0, 0x00e1, 0x00e2, 0x00e3, 0x00e4, 0x00e5, 0x00e6, 0x00e7,
    0x00e8, 0x00e9, 0x00ea, 0x00eb, 0x00ec, 0x00ed, 0x00ee, 0x00ef,
    0x00f0, 0x00f1, 0x00f2, 0x00f3, 0x00f4, 0x00f5, 0x00f6, 0x00f7,
    0x00f8, 0x00f9, 0x00fa, 0x00fb, 0x00fc, 0x00fd, 0x00fe, 0x00ff
  },
  /* IBM Codepage 437 mapped to Unicode */
  {
    0x0000, 0x263a, 0x263b, 0x2665, 0x2666, 0x2663, 0x2660, 0x2022, 
    0x25d8, 0x25cb, 0x25d9, 0x2642, 0x2640, 0x266a, 0x266b, 0x263c,
    0x25ba, 0x25c4, 0x2195, 0x203c, 0x00b6, 0x00a7, 0x25ac, 0x21a8,
    0x2191, 0x2193, 0x2192, 0x2190, 0x221f, 0x2194, 0x25b2, 0x25bc,
    0x0020, 0x0021, 0x0022, 0x0023, 0x0024, 0x0025, 0x0026, 0x0027,
    0x0028, 0x0029, 0x002a, 0x002b, 0x002c, 0x002d, 0x002e, 0x002f,
    0x0030, 0x0031, 0x0032, 0x0033, 0x0034, 0x0035, 0x0036, 0x0037,
    0x0038, 0x0039, 0x003a, 0x003b, 0x003c, 0x003d, 0x003e, 0x003f,
    0x0040, 0x0041, 0x0042, 0x0043, 0x0044, 0x0045, 0x0046, 0x0047,
    0x0048, 0x0049, 0x004a, 0x004b, 0x004c, 0x004d, 0x004e, 0x004f,
    0x0050, 0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056, 0x0057,
    0x0058, 0x0059, 0x005a, 0x005b, 0x005c, 0x005d, 0x005e, 0x005f,
    0x0060, 0x0061, 0x0062, 0x0063, 0x0064, 0x0065, 0x0066, 0x0067,
    0x0068, 0x0069, 0x006a, 0x006b, 0x006c, 0x006d, 0x006e, 0x006f,
    0x0070, 0x0071, 0x0072, 0x0073, 0x0074, 0x0075, 0x0076, 0x0077,
    0x0078, 0x0079, 0x007a, 0x007b, 0x007c, 0x007d, 0x007e, 0x2302,
    0x00c7, 0x00fc, 0x00e9, 0x00e2, 0x00e4, 0x00e0, 0x00e5, 0x00e7,
    0x00ea, 0x00eb, 0x00e8, 0x00ef, 0x00ee, 0x00ec, 0x00c4, 0x00c5,
    0x00c9, 0x00e6, 0x00c6, 0x00f4, 0x00f6, 0x00f2, 0x00fb, 0x00f9,
    0x00ff, 0x00d6, 0x00dc, 0x00a2, 0x00a3, 0x00a5, 0x20a7, 0x0192,
    0x00e1, 0x00ed, 0x00f3, 0x00fa, 0x00f1, 0x00d1, 0x00aa, 0x00ba,
    0x00bf, 0x2310, 0x00ac, 0x00bd, 0x00bc, 0x00a1, 0x00ab, 0x00bb,
    0x2591, 0x2592, 0x2593, 0x2502, 0x2524, 0x2561, 0x2562, 0x2556,
    0x2555, 0x2563, 0x2551, 0x2557, 0x255d, 0x255c, 0x255b, 0x2510,
    0x2514, 0x2534, 0x252c, 0x251c, 0x2500, 0x253c, 0x255e, 0x255f,
    0x255a, 0x2554, 0x2569, 0x2566, 0x2560, 0x2550, 0x256c, 0x2567,
    0x2568, 0x2564, 0x2565, 0x2559, 0x2558, 0x2552, 0x2553, 0x256b,
    0x256a, 0x2518, 0x250c, 0x2588, 0x2584, 0x258c, 0x2590, 0x2580,
    0x03b1, 0x00df, 0x0393, 0x03c0, 0x03a3, 0x03c3, 0x00b5, 0x03c4,
    0x03a6, 0x0398, 0x03a9, 0x03b4, 0x221e, 0x03c6, 0x03b5, 0x2229,
    0x2261, 0x00b1, 0x2265, 0x2264, 0x2320, 0x2321, 0x00f7, 0x2248,
    0x00b0, 0x2219, 0x00b7, 0x221a, 0x207f, 0x00b2, 0x25a0, 0x00a0
  }, 
  /* User mapping -- default to codes for direct font mapping */
  {
    0xf000, 0xf001, 0xf002, 0xf003, 0xf004, 0xf005, 0xf006, 0xf007,
    0xf008, 0xf009, 0xf00a, 0xf00b, 0xf00c, 0xf00d, 0xf00e, 0xf00f,
    0xf010, 0xf011, 0xf012, 0xf013, 0xf014, 0xf015, 0xf016, 0xf017,
    0xf018, 0xf019, 0xf01a, 0xf01b, 0xf01c, 0xf01d, 0xf01e, 0xf01f,
    0xf020, 0xf021, 0xf022, 0xf023, 0xf024, 0xf025, 0xf026, 0xf027,
    0xf028, 0xf029, 0xf02a, 0xf02b, 0xf02c, 0xf02d, 0xf02e, 0xf02f,
    0xf030, 0xf031, 0xf032, 0xf033, 0xf034, 0xf035, 0xf036, 0xf037,
    0xf038, 0xf039, 0xf03a, 0xf03b, 0xf03c, 0xf03d, 0xf03e, 0xf03f,
    0xf040, 0xf041, 0xf042, 0xf043, 0xf044, 0xf045, 0xf046, 0xf047,
    0xf048, 0xf049, 0xf04a, 0xf04b, 0xf04c, 0xf04d, 0xf04e, 0xf04f,
    0xf050, 0xf051, 0xf052, 0xf053, 0xf054, 0xf055, 0xf056, 0xf057,
    0xf058, 0xf059, 0xf05a, 0xf05b, 0xf05c, 0xf05d, 0xf05e, 0xf05f,
    0xf060, 0xf061, 0xf062, 0xf063, 0xf064, 0xf065, 0xf066, 0xf067,
    0xf068, 0xf069, 0xf06a, 0xf06b, 0xf06c, 0xf06d, 0xf06e, 0xf06f,
    0xf070, 0xf071, 0xf072, 0xf073, 0xf074, 0xf075, 0xf076, 0xf077,
    0xf078, 0xf079, 0xf07a, 0xf07b, 0xf07c, 0xf07d, 0xf07e, 0xf07f,
    0xf080, 0xf081, 0xf082, 0xf083, 0xf084, 0xf085, 0xf086, 0xf087,
    0xf088, 0xf089, 0xf08a, 0xf08b, 0xf08c, 0xf08d, 0xf08e, 0xf08f,
    0xf090, 0xf091, 0xf092, 0xf093, 0xf094, 0xf095, 0xf096, 0xf097,
    0xf098, 0xf099, 0xf09a, 0xf09b, 0xf09c, 0xf09d, 0xf09e, 0xf09f,
    0xf0a0, 0xf0a1, 0xf0a2, 0xf0a3, 0xf0a4, 0xf0a5, 0xf0a6, 0xf0a7,
    0xf0a8, 0xf0a9, 0xf0aa, 0xf0ab, 0xf0ac, 0xf0ad, 0xf0ae, 0xf0af,
    0xf0b0, 0xf0b1, 0xf0b2, 0xf0b3, 0xf0b4, 0xf0b5, 0xf0b6, 0xf0b7,
    0xf0b8, 0xf0b9, 0xf0ba, 0xf0bb, 0xf0bc, 0xf0bd, 0xf0be, 0xf0bf,
    0xf0c0, 0xf0c1, 0xf0c2, 0xf0c3, 0xf0c4, 0xf0c5, 0xf0c6, 0xf0c7,
    0xf0c8, 0xf0c9, 0xf0ca, 0xf0cb, 0xf0cc, 0xf0cd, 0xf0ce, 0xf0cf,
    0xf0d0, 0xf0d1, 0xf0d2, 0xf0d3, 0xf0d4, 0xf0d5, 0xf0d6, 0xf0d7,
    0xf0d8, 0xf0d9, 0xf0da, 0xf0db, 0xf0dc, 0xf0dd, 0xf0de, 0xf0df,
    0xf0e0, 0xf0e1, 0xf0e2, 0xf0e3, 0xf0e4, 0xf0e5, 0xf0e6, 0xf0e7,
    0xf0e8, 0xf0e9, 0xf0ea, 0xf0eb, 0xf0ec, 0xf0ed, 0xf0ee, 0xf0ef,
    0xf0f0, 0xf0f1, 0xf0f2, 0xf0f3, 0xf0f4, 0xf0f5, 0xf0f6, 0xf0f7,
    0xf0f8, 0xf0f9, 0xf0fa, 0xf0fb, 0xf0fc, 0xf0fd, 0xf0fe, 0xf0ff
  }
};

/* the above mappings are not invertible - this is just a best effort */
static unsigned char * inv_translate = NULL;
static unsigned char inv_norm_transl[E_TABSZ];
static unsigned char * inverse_translations[4] = { NULL, NULL, NULL, NULL };

static void set_inverse_transl(int i)
{
	int j, glyph;
	unsigned short *p = translations[i];
	unsigned char *q = inverse_translations[i];

	if (!q) {
		/* slightly messy to avoid calling kmalloc too early */
		q = inverse_translations[i] = ((i == LAT1_MAP)
			? inv_norm_transl
			: (unsigned char *) kmalloc(E_TABSZ, GFP_KERNEL));
		if (!q)
			return;
	}
	for (j=0; j<E_TABSZ; j++)
		q[j] = 0;
	for (j=0; j<E_TABSZ; j++)
		if (q[glyph = conv_uni_to_pc(p[j])] < 32) 
		  /* prefer '-' above SHY etc. */
		  q[glyph] = j;
}

unsigned short *set_translate(int m)
{
	if (!inverse_translations[m])
		set_inverse_transl(m);
	inv_translate = inverse_translations[m];
	return translations[m];
}

/*
 * Inverse translation is impossible for several reasons:
 * 1. The translation maps are not 1-1
 * 2. The text may have been written while a different translation map
 *    was active
 * Still, it is now possible to a certain extent to cut and paste non-ASCII.
 */
unsigned char inverse_translate(unsigned char c) {
	return ((inv_translate && inv_translate[c]) ? inv_translate[c] : c);
}

/*
 * Load customizable translation table
 * arg points to a 256 byte translation table.
 *
 * The "old" variants are for translation directly to font (using the
 * 0xf000-0xf0ff "transparent" Unicodes) whereas the "new" variants set
 * unicodes explictly.
 */
int con_set_trans_old(unsigned char * arg)
{
	int i;
	unsigned short *p = translations[USER_MAP];

	i = verify_area(VERIFY_READ, (void *)arg, E_TABSZ);
	if (i)
		return i;

	for (i=0; i<E_TABSZ ; i++)
		p[i] = UNI_DIRECT_BASE | get_user(arg+i);

	set_inverse_transl(USER_MAP);
	return 0;
}

int con_get_trans_old(unsigned char * arg)
{
	int i, ch;
	unsigned short *p = translations[USER_MAP];

	i = verify_area(VERIFY_WRITE, (void *)arg, E_TABSZ);
	if (i)
		return i;

	for (i=0; i<E_TABSZ ; i++)
	  {
	    ch = conv_uni_to_pc(p[i]);
	    put_user((ch & ~0xff) ? 0 : ch, arg+i);
	  }
	return 0;
}
int con_set_trans_new(ushort * arg)
{
	int i;
	unsigned short *p = translations[USER_MAP];

	i = verify_area(VERIFY_READ, (void *)arg,
			E_TABSZ*sizeof(unsigned short));
	if (i)
		return i;

	for (i=0; i<E_TABSZ ; i++)
	  p[i] = get_user(arg+i);

	set_inverse_transl(USER_MAP);
	return 0;
}

int con_get_trans_new(ushort * arg)
{
	int i;
	unsigned short *p = translations[USER_MAP];

	i = verify_area(VERIFY_WRITE, (void *)arg,
			E_TABSZ*sizeof(unsigned short));
	if (i)
		return i;

	for (i=0; i<E_TABSZ ; i++)
	  put_user(p[i], arg+i);
	
	return 0;
}

/*
 * Unicode -> current font conversion 
 *
 * A font has at most 512 chars, usually 256.
 * But one font position may represent several Unicode chars
 * (and moreover, hashtables work best when they are not too full),
 * so pick HASHSIZE somewhat larger than 512.
 * Since there are likely to be long consecutive stretches
 * (like U+0000 to U+00FF), HASHSTEP should not be too small.
 * Searches longer than MAXHASHLEVEL steps are refused, unless
 * requested explicitly.
 *
 * Note: no conversion tables are compiled in, so the user
 * must supply an explicit mapping herself. See kbd-0.90 (or an
 * earlier kernel version) for the default Unicode-to-PC mapping.
 * Usually, the mapping will be loaded simultaneously with the font.
 */

#include "uni_hash.tbl"		/* Include hash tables & parameters */

int hashtable_contents_valid = 1;

void
con_clear_unimap(struct unimapinit *ui) {
	int i;

	/* read advisory values for hash algorithm */
	hashsize = ui->advised_hashsize;
	if (hashsize < 256 || hashsize > HASHSIZE)
	  hashsize = HASHSIZE;
	hashstep = (ui->advised_hashstep % hashsize);
	if (hashstep < 64)
	  hashstep = HASHSTEP;
	maxhashlevel = ui->advised_hashlevel;
	if (!maxhashlevel)
	  maxhashlevel = MAXHASHLEVEL;
	if (maxhashlevel > hashsize)
	  maxhashlevel = hashsize;

	/* initialize */
	hashlevel = 0;
	for (i=0; i<hashsize; i++)
	  hashtable[i].unicode = 0xffff;
	hashtable_contents_valid = 1;
}

int
con_set_unimap(ushort ct, struct unipair *list){
	int i, lct;
	ushort u, hu;
	struct unimapinit hashdefaults = { 0, 0, 0 };

	if (!hashtable_contents_valid)
	  con_clear_unimap(&hashdefaults);
	while(ct) {
	    u = get_user(&list->unicode);
	    i = u % hashsize;
	    lct = 1;
	    while ((hu = hashtable[i].unicode) != 0xffff && hu != u) {
		if (lct++ >=  maxhashlevel)
		  return -ENOMEM;
		i += hashstep;
		if (i >= hashsize)
		  i -= hashsize;
	    }
	    if (lct > hashlevel)
	      hashlevel = lct;
	    hashtable[i].unicode = u;
	    hashtable[i].fontpos = get_user(&list->fontpos);
	    list++;
	    ct--;
	}

	for ( i = 0 ; i <= 3 ; i++ )
	  set_inverse_transl(i); /* Update all inverse translations */

	return 0;
}

int
con_get_unimap(ushort ct, ushort *uct, struct unipair *list){
	int i, ect;

	ect = 0;
	if (hashtable_contents_valid)
	  for (i = 0; i<hashsize; i++)
	    if (hashtable[i].unicode != 0xffff) {
		if (ect++ < ct) {
		    put_user(hashtable[i].unicode, &list->unicode);
		    put_user(hashtable[i].fontpos, &list->fontpos);
		    list++;
		}
	    }
	put_user(ect, uct);
	return ((ect <= ct) ? 0 : -ENOMEM);
}

int
conv_uni_to_pc(long ucs) {
      int i, h;
      
      /* Only 16-bit codes supported at this time */
      if (ucs > 0xffff)
	ucs = 0xfffd;		/* U+FFFD: REPLACEMENT CHARACTER */
      else if (ucs < 0x20 || ucs >= 0xfffe)
	return -1;		/* Not a printable character */
      else if (ucs == 0xfeff || (ucs >= 0x200a && ucs <= 0x200f))
	return -2;		/* Zero-width space */
      /*
       * UNI_DIRECT_BASE indicates the start of the region in the User Zone
       * which always has a 1:1 mapping to the currently loaded font.  The
       * UNI_DIRECT_MASK indicates the bit span of the region.
       */
      else if ( (ucs & ~UNI_DIRECT_MASK) == UNI_DIRECT_BASE )
	return ucs & UNI_DIRECT_MASK;

      if (!hashtable_contents_valid)
	return -3;
      
      h = ucs % hashsize;
      for (i = 0; i < hashlevel; i++) {
	  if (hashtable[h].unicode == ucs)
	    return hashtable[h].fontpos;
	  if ((h += hashstep) >= hashsize)
	    h -= hashsize;
      }

      return -4;		/* not found */
}