drivers/s390/char/keyboard.c - kernel/msm-4.9 - Gitiles

 /*
  *    ebcdic keycode functions for s390 console drivers
  *
  *  S390 version
  *    Copyright IBM Corp. 2003
  *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
  */

 #include <linux/module.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/sysrq.h>

 #include <linux/consolemap.h>
 #include <linux/kbd_kern.h>
 #include <linux/kbd_diacr.h>
 #include <asm/uaccess.h>

 #include "keyboard.h"

 /*
  * Handler Tables.
  */
 #define K_HANDLERS\
 	k_self,		k_fn,		k_spec,		k_ignore,\
 	k_dead,		k_ignore,	k_ignore,	k_ignore,\
 	k_ignore,	k_ignore,	k_ignore,	k_ignore,\
 	k_ignore,	k_ignore,	k_ignore,	k_ignore

 typedef void (k_handler_fn)(struct kbd_data *, unsigned char);
 static k_handler_fn K_HANDLERS;
 static k_handler_fn *k_handler[16] = { K_HANDLERS };

 /* maximum values each key_handler can handle */
 static const int kbd_max_vals[] = {
 	255, ARRAY_SIZE(func_table) - 1, NR_FN_HANDLER - 1, 0,
 	NR_DEAD - 1, 0, 0, 0, 0, 0, 0, 0, 0, 0
 };
 static const int KBD_NR_TYPES = ARRAY_SIZE(kbd_max_vals);

 static unsigned char ret_diacr[NR_DEAD] = {
 	'`', '\'', '^', '~', '"', ','
 };

 /*
  * Alloc/free of kbd_data structures.
  */
 struct kbd_data *
 kbd_alloc(void) {
 	struct kbd_data *kbd;
 	int i;

 	kbd = kzalloc(sizeof(struct kbd_data), GFP_KERNEL);
 	if (!kbd)
 		goto out;
 	kbd->key_maps = kzalloc(sizeof(key_maps), GFP_KERNEL);
 	if (!kbd->key_maps)
 		goto out_kbd;
 	for (i = 0; i < ARRAY_SIZE(key_maps); i++) {
 		if (key_maps[i]) {
 			kbd->key_maps[i] = kmemdup(key_maps[i],
 						   sizeof(u_short) * NR_KEYS,
 						   GFP_KERNEL);
 			if (!kbd->key_maps[i])
 				goto out_maps;
 		}
 	}
 	kbd->func_table = kzalloc(sizeof(func_table), GFP_KERNEL);
 	if (!kbd->func_table)
 		goto out_maps;
 	for (i = 0; i < ARRAY_SIZE(func_table); i++) {
 		if (func_table[i]) {
 			kbd->func_table[i] = kstrdup(func_table[i],
 						     GFP_KERNEL);
 			if (!kbd->func_table[i])
 				goto out_func;
 		}
 	}
 	kbd->fn_handler =
 		kzalloc(sizeof(fn_handler_fn *) * NR_FN_HANDLER, GFP_KERNEL);
 	if (!kbd->fn_handler)
 		goto out_func;
 	kbd->accent_table = kmemdup(accent_table,
 				    sizeof(struct kbdiacruc) * MAX_DIACR,
 				    GFP_KERNEL);
 	if (!kbd->accent_table)
 		goto out_fn_handler;
 	kbd->accent_table_size = accent_table_size;
 	return kbd;

 out_fn_handler:
 	kfree(kbd->fn_handler);
 out_func:
 	for (i = 0; i < ARRAY_SIZE(func_table); i++)
 		kfree(kbd->func_table[i]);
 	kfree(kbd->func_table);
 out_maps:
 	for (i = 0; i < ARRAY_SIZE(key_maps); i++)
 		kfree(kbd->key_maps[i]);
 	kfree(kbd->key_maps);
 out_kbd:
 	kfree(kbd);
 out:
 	return NULL;
 }

 void
 kbd_free(struct kbd_data *kbd)
 {
 	int i;

 	kfree(kbd->accent_table);
 	kfree(kbd->fn_handler);
 	for (i = 0; i < ARRAY_SIZE(func_table); i++)
 		kfree(kbd->func_table[i]);
 	kfree(kbd->func_table);
 	for (i = 0; i < ARRAY_SIZE(key_maps); i++)
 		kfree(kbd->key_maps[i]);
 	kfree(kbd->key_maps);
 	kfree(kbd);
 }

 /*
  * Generate ascii -> ebcdic translation table from kbd_data.
  */
 void
 kbd_ascebc(struct kbd_data *kbd, unsigned char *ascebc)
 {
 	unsigned short *keymap, keysym;
 	int i, j, k;

 	memset(ascebc, 0x40, 256);
 	for (i = 0; i < ARRAY_SIZE(key_maps); i++) {
 		keymap = kbd->key_maps[i];
 		if (!keymap)
 			continue;
 		for (j = 0; j < NR_KEYS; j++) {
 			k = ((i & 1) << 7) + j;
 			keysym = keymap[j];
 			if (KTYP(keysym) == (KT_LATIN | 0xf0) ||
 			    KTYP(keysym) == (KT_LETTER | 0xf0))
 				ascebc[KVAL(keysym)] = k;
 			else if (KTYP(keysym) == (KT_DEAD | 0xf0))
 				ascebc[ret_diacr[KVAL(keysym)]] = k;
 		}
 	}
 }

 #if 0
 /*
  * Generate ebcdic -> ascii translation table from kbd_data.
  */
 void
 kbd_ebcasc(struct kbd_data *kbd, unsigned char *ebcasc)
 {
 	unsigned short *keymap, keysym;
 	int i, j, k;

 	memset(ebcasc, ' ', 256);
 	for (i = 0; i < ARRAY_SIZE(key_maps); i++) {
 		keymap = kbd->key_maps[i];
 		if (!keymap)
 			continue;
 		for (j = 0; j < NR_KEYS; j++) {
 			keysym = keymap[j];
 			k = ((i & 1) << 7) + j;
 			if (KTYP(keysym) == (KT_LATIN | 0xf0) ||
 			    KTYP(keysym) == (KT_LETTER | 0xf0))
 				ebcasc[k] = KVAL(keysym);
 			else if (KTYP(keysym) == (KT_DEAD | 0xf0))
 				ebcasc[k] = ret_diacr[KVAL(keysym)];
 		}
 	}
 }
 #endif

 /*
  * We have a combining character DIACR here, followed by the character CH.
  * If the combination occurs in the table, return the corresponding value.
  * Otherwise, if CH is a space or equals DIACR, return DIACR.
  * Otherwise, conclude that DIACR was not combining after all,
  * queue it and return CH.
  */
 static unsigned int
 handle_diacr(struct kbd_data *kbd, unsigned int ch)
 {
 	int i, d;

 	d = kbd->diacr;
 	kbd->diacr = 0;

 	for (i = 0; i < kbd->accent_table_size; i++) {
 		if (kbd->accent_table[i].diacr == d &&
 		    kbd->accent_table[i].base == ch)
 			return kbd->accent_table[i].result;
 	}

 	if (ch == ' ' || ch == d)
 		return d;

 	kbd_put_queue(kbd->port, d);
 	return ch;
 }

 /*
  * Handle dead key.
  */
 static void
 k_dead(struct kbd_data *kbd, unsigned char value)
 {
 	value = ret_diacr[value];
 	kbd->diacr = (kbd->diacr ? handle_diacr(kbd, value) : value);
 }

 /*
  * Normal character handler.
  */
 static void
 k_self(struct kbd_data *kbd, unsigned char value)
 {
 	if (kbd->diacr)
 		value = handle_diacr(kbd, value);
 	kbd_put_queue(kbd->port, value);
 }

 /*
  * Special key handlers
  */
 static void
 k_ignore(struct kbd_data *kbd, unsigned char value)
 {
 }

 /*
  * Function key handler.
  */
 static void
 k_fn(struct kbd_data *kbd, unsigned char value)
 {
 	if (kbd->func_table[value])
 		kbd_puts_queue(kbd->port, kbd->func_table[value]);
 }

 static void
 k_spec(struct kbd_data *kbd, unsigned char value)
 {
 	if (value >= NR_FN_HANDLER)
 		return;
 	if (kbd->fn_handler[value])
 		kbd->fn_handler[value](kbd);
 }

 /*
  * Put utf8 character to tty flip buffer.
  * UTF-8 is defined for words of up to 31 bits,
  * but we need only 16 bits here
  */
 static void
 to_utf8(struct tty_port *port, ushort c)
 {
 	if (c < 0x80)
 		/*  0******* */
 		kbd_put_queue(port, c);
 	else if (c < 0x800) {
 		/* 110***** 10****** */
 		kbd_put_queue(port, 0xc0 | (c >> 6));
 		kbd_put_queue(port, 0x80 | (c & 0x3f));
 	} else {
 		/* 1110**** 10****** 10****** */
 		kbd_put_queue(port, 0xe0 | (c >> 12));
 		kbd_put_queue(port, 0x80 | ((c >> 6) & 0x3f));
 		kbd_put_queue(port, 0x80 | (c & 0x3f));
 	}
 }

 /*
  * Process keycode.
  */
 void
 kbd_keycode(struct kbd_data *kbd, unsigned int keycode)
 {
 	unsigned short keysym;
 	unsigned char type, value;

 	if (!kbd)
 		return;

 	if (keycode >= 384)
 		keysym = kbd->key_maps[5][keycode - 384];
 	else if (keycode >= 256)
 		keysym = kbd->key_maps[4][keycode - 256];
 	else if (keycode >= 128)
 		keysym = kbd->key_maps[1][keycode - 128];
 	else
 		keysym = kbd->key_maps[0][keycode];

 	type = KTYP(keysym);
 	if (type >= 0xf0) {
 		type -= 0xf0;
 		if (type == KT_LETTER)
 			type = KT_LATIN;
 		value = KVAL(keysym);
 #ifdef CONFIG_MAGIC_SYSRQ	       /* Handle the SysRq Hack */
 		if (kbd->sysrq) {
 			if (kbd->sysrq == K(KT_LATIN, '-')) {
 				kbd->sysrq = 0;
 				handle_sysrq(value);
 				return;
 			}
 			if (value == '-') {
 				kbd->sysrq = K(KT_LATIN, '-');
 				return;
 			}
 			/* Incomplete sysrq sequence. */
 			(*k_handler[KTYP(kbd->sysrq)])(kbd, KVAL(kbd->sysrq));
 			kbd->sysrq = 0;
 		} else if ((type == KT_LATIN && value == '^') ||
 			   (type == KT_DEAD && ret_diacr[value] == '^')) {
 			kbd->sysrq = K(type, value);
 			return;
 		}
 #endif
 		(*k_handler[type])(kbd, value);
 	} else
 		to_utf8(kbd->port, keysym);
 }

 /*
  * Ioctl stuff.
  */
 static int
 do_kdsk_ioctl(struct kbd_data *kbd, struct kbentry __user *user_kbe,
 	      int cmd, int perm)
 {
 	struct kbentry tmp;
 	ushort *key_map, val, ov;

 	if (copy_from_user(&tmp, user_kbe, sizeof(struct kbentry)))
 		return -EFAULT;
 #if NR_KEYS < 256
 	if (tmp.kb_index >= NR_KEYS)
 		return -EINVAL;
 #endif
 #if MAX_NR_KEYMAPS < 256
 	if (tmp.kb_table >= MAX_NR_KEYMAPS)
 		return -EINVAL;
 #endif

 	switch (cmd) {
 	case KDGKBENT:
 		key_map = kbd->key_maps[tmp.kb_table];
 		if (key_map) {
 		    val = U(key_map[tmp.kb_index]);
 		    if (KTYP(val) >= KBD_NR_TYPES)
 			val = K_HOLE;
 		} else
 		    val = (tmp.kb_index ? K_HOLE : K_NOSUCHMAP);
 		return put_user(val, &user_kbe->kb_value);
 	case KDSKBENT:
 		if (!perm)
 			return -EPERM;
 		if (!tmp.kb_index && tmp.kb_value == K_NOSUCHMAP) {
 			/* disallocate map */
 			key_map = kbd->key_maps[tmp.kb_table];
 			if (key_map) {
 			    kbd->key_maps[tmp.kb_table] = NULL;
 			    kfree(key_map);
 			}
 			break;
 		}

 		if (KTYP(tmp.kb_value) >= KBD_NR_TYPES)
 			return -EINVAL;
 		if (KVAL(tmp.kb_value) > kbd_max_vals[KTYP(tmp.kb_value)])
 			return -EINVAL;

 		if (!(key_map = kbd->key_maps[tmp.kb_table])) {
 			int j;

 			key_map = kmalloc(sizeof(plain_map),
 						     GFP_KERNEL);
 			if (!key_map)
 				return -ENOMEM;
 			kbd->key_maps[tmp.kb_table] = key_map;
 			for (j = 0; j < NR_KEYS; j++)
 				key_map[j] = U(K_HOLE);
 		}
 		ov = U(key_map[tmp.kb_index]);
 		if (tmp.kb_value == ov)
 			break;	/* nothing to do */
 		/*
 		 * Attention Key.
 		 */
 		if (((ov == K_SAK) || (tmp.kb_value == K_SAK)) &&
 		    !capable(CAP_SYS_ADMIN))
 			return -EPERM;
 		key_map[tmp.kb_index] = U(tmp.kb_value);
 		break;
 	}
 	return 0;
 }

 static int
 do_kdgkb_ioctl(struct kbd_data *kbd, struct kbsentry __user *u_kbs,
 	       int cmd, int perm)
 {
 	unsigned char kb_func;
 	char *p;
 	int len;

 	/* Get u_kbs->kb_func. */
 	if (get_user(kb_func, &u_kbs->kb_func))
 		return -EFAULT;
 #if MAX_NR_FUNC < 256
 	if (kb_func >= MAX_NR_FUNC)
 		return -EINVAL;
 #endif

 	switch (cmd) {
 	case KDGKBSENT:
 		p = kbd->func_table[kb_func];
 		if (p) {
 			len = strlen(p);
 			if (len >= sizeof(u_kbs->kb_string))
 				len = sizeof(u_kbs->kb_string) - 1;
 			if (copy_to_user(u_kbs->kb_string, p, len))
 				return -EFAULT;
 		} else
 			len = 0;
 		if (put_user('\0', u_kbs->kb_string + len))
 			return -EFAULT;
 		break;
 	case KDSKBSENT:
 		if (!perm)
 			return -EPERM;
 		len = strnlen_user(u_kbs->kb_string,
 				   sizeof(u_kbs->kb_string) - 1);
 		if (!len)
 			return -EFAULT;
 		if (len > sizeof(u_kbs->kb_string) - 1)
 			return -EINVAL;
 		p = kmalloc(len + 1, GFP_KERNEL);
 		if (!p)
 			return -ENOMEM;
 		if (copy_from_user(p, u_kbs->kb_string, len)) {
 			kfree(p);
 			return -EFAULT;
 		}
 		p[len] = 0;
 		kfree(kbd->func_table[kb_func]);
 		kbd->func_table[kb_func] = p;
 		break;
 	}
 	return 0;
 }

 int kbd_ioctl(struct kbd_data *kbd, unsigned int cmd, unsigned long arg)
 {
 	struct tty_struct *tty;
 	void __user *argp;
 	unsigned int ct;
 	int perm;

 	argp = (void __user *)arg;

 	/*
 	 * To have permissions to do most of the vt ioctls, we either have
 	 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
 	 */
 	tty = tty_port_tty_get(kbd->port);
 	/* FIXME this test is pretty racy */
 	perm = current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG);
 	tty_kref_put(tty);
 	switch (cmd) {
 	case KDGKBTYPE:
 		return put_user(KB_101, (char __user *)argp);
 	case KDGKBENT:
 	case KDSKBENT:
 		return do_kdsk_ioctl(kbd, argp, cmd, perm);
 	case KDGKBSENT:
 	case KDSKBSENT:
 		return do_kdgkb_ioctl(kbd, argp, cmd, perm);
 	case KDGKBDIACR:
 	{
 		struct kbdiacrs __user *a = argp;
 		struct kbdiacr diacr;
 		int i;

 		if (put_user(kbd->accent_table_size, &a->kb_cnt))
 			return -EFAULT;
 		for (i = 0; i < kbd->accent_table_size; i++) {
 			diacr.diacr = kbd->accent_table[i].diacr;
 			diacr.base = kbd->accent_table[i].base;
 			diacr.result = kbd->accent_table[i].result;
 			if (copy_to_user(a->kbdiacr + i, &diacr, sizeof(struct kbdiacr)))
 			return -EFAULT;
 		}
 		return 0;
 	}
 	case KDGKBDIACRUC:
 	{
 		struct kbdiacrsuc __user *a = argp;

 		ct = kbd->accent_table_size;
 		if (put_user(ct, &a->kb_cnt))
 			return -EFAULT;
 		if (copy_to_user(a->kbdiacruc, kbd->accent_table,
 				 ct * sizeof(struct kbdiacruc)))
 			return -EFAULT;
 		return 0;
 	}
 	case KDSKBDIACR:
 	{
 		struct kbdiacrs __user *a = argp;
 		struct kbdiacr diacr;
 		int i;

 		if (!perm)
 			return -EPERM;
 		if (get_user(ct, &a->kb_cnt))
 			return -EFAULT;
 		if (ct >= MAX_DIACR)
 			return -EINVAL;
 		kbd->accent_table_size = ct;
 		for (i = 0; i < ct; i++) {
 			if (copy_from_user(&diacr, a->kbdiacr + i, sizeof(struct kbdiacr)))
 				return -EFAULT;
 			kbd->accent_table[i].diacr = diacr.diacr;
 			kbd->accent_table[i].base = diacr.base;
 			kbd->accent_table[i].result = diacr.result;
 		}
 		return 0;
 	}
 	case KDSKBDIACRUC:
 	{
 		struct kbdiacrsuc __user *a = argp;

 		if (!perm)
 			return -EPERM;
 		if (get_user(ct, &a->kb_cnt))
 			return -EFAULT;
 		if (ct >= MAX_DIACR)
 			return -EINVAL;
 		kbd->accent_table_size = ct;
 		if (copy_from_user(kbd->accent_table, a->kbdiacruc,
 				   ct * sizeof(struct kbdiacruc)))
 			return -EFAULT;
 		return 0;
 	}
 	default:
 		return -ENOIOCTLCMD;
 	}
 }

 EXPORT_SYMBOL(kbd_ioctl);
 EXPORT_SYMBOL(kbd_ascebc);
 EXPORT_SYMBOL(kbd_free);
 EXPORT_SYMBOL(kbd_alloc);
 EXPORT_SYMBOL(kbd_keycode);
	/*
	* ebcdic keycode functions for s390 console drivers
	*
	* S390 version
	* Copyright IBM Corp. 2003
	* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
	*/

	#include <linux/module.h>
	#include <linux/sched.h>
	#include <linux/slab.h>
	#include <linux/sysrq.h>

	#include <linux/consolemap.h>
	#include <linux/kbd_kern.h>
	#include <linux/kbd_diacr.h>
	#include <asm/uaccess.h>

	#include "keyboard.h"

	/*
	* Handler Tables.
	*/
	#define K_HANDLERS\
	k_self, k_fn, k_spec, k_ignore,\
	k_dead, k_ignore, k_ignore, k_ignore,\
	k_ignore, k_ignore, k_ignore, k_ignore,\
	k_ignore, k_ignore, k_ignore, k_ignore

	typedef void (k_handler_fn)(struct kbd_data *, unsigned char);
	static k_handler_fn K_HANDLERS;
	static k_handler_fn *k_handler[16] = { K_HANDLERS };

	/* maximum values each key_handler can handle */
	static const int kbd_max_vals[] = {
	255, ARRAY_SIZE(func_table) - 1, NR_FN_HANDLER - 1, 0,
	NR_DEAD - 1, 0, 0, 0, 0, 0, 0, 0, 0, 0
	};
	static const int KBD_NR_TYPES = ARRAY_SIZE(kbd_max_vals);

	static unsigned char ret_diacr[NR_DEAD] = {
	'`', '\'', '^', '~', '"', ','
	};

	/*
	* Alloc/free of kbd_data structures.
	*/
	struct kbd_data *
	kbd_alloc(void) {
	struct kbd_data *kbd;
	int i;

	kbd = kzalloc(sizeof(struct kbd_data), GFP_KERNEL);
	if (!kbd)
	goto out;
	kbd->key_maps = kzalloc(sizeof(key_maps), GFP_KERNEL);
	if (!kbd->key_maps)
	goto out_kbd;
	for (i = 0; i < ARRAY_SIZE(key_maps); i++) {
	if (key_maps[i]) {
	kbd->key_maps[i] = kmemdup(key_maps[i],
	sizeof(u_short) * NR_KEYS,
	GFP_KERNEL);
	if (!kbd->key_maps[i])
	goto out_maps;
	}
	}
	kbd->func_table = kzalloc(sizeof(func_table), GFP_KERNEL);
	if (!kbd->func_table)
	goto out_maps;
	for (i = 0; i < ARRAY_SIZE(func_table); i++) {
	if (func_table[i]) {
	kbd->func_table[i] = kstrdup(func_table[i],
	GFP_KERNEL);
	if (!kbd->func_table[i])
	goto out_func;
	}
	}
	kbd->fn_handler =
	kzalloc(sizeof(fn_handler_fn ) NR_FN_HANDLER, GFP_KERNEL);
	if (!kbd->fn_handler)
	goto out_func;
	kbd->accent_table = kmemdup(accent_table,
	sizeof(struct kbdiacruc) * MAX_DIACR,
	GFP_KERNEL);
	if (!kbd->accent_table)
	goto out_fn_handler;
	kbd->accent_table_size = accent_table_size;
	return kbd;

	out_fn_handler:
	kfree(kbd->fn_handler);
	out_func:
	for (i = 0; i < ARRAY_SIZE(func_table); i++)
	kfree(kbd->func_table[i]);
	kfree(kbd->func_table);
	out_maps:
	for (i = 0; i < ARRAY_SIZE(key_maps); i++)
	kfree(kbd->key_maps[i]);
	kfree(kbd->key_maps);
	out_kbd:
	kfree(kbd);
	out:
	return NULL;
	}

	void
	kbd_free(struct kbd_data *kbd)
	{
	int i;

	kfree(kbd->accent_table);
	kfree(kbd->fn_handler);
	for (i = 0; i < ARRAY_SIZE(func_table); i++)
	kfree(kbd->func_table[i]);
	kfree(kbd->func_table);
	for (i = 0; i < ARRAY_SIZE(key_maps); i++)
	kfree(kbd->key_maps[i]);
	kfree(kbd->key_maps);
	kfree(kbd);
	}

	/*
	* Generate ascii -> ebcdic translation table from kbd_data.
	*/
	void
	kbd_ascebc(struct kbd_data kbd, unsigned char ascebc)
	{
	unsigned short *keymap, keysym;
	int i, j, k;

	memset(ascebc, 0x40, 256);
	for (i = 0; i < ARRAY_SIZE(key_maps); i++) {
	keymap = kbd->key_maps[i];
	if (!keymap)
	continue;
	for (j = 0; j < NR_KEYS; j++) {
	k = ((i & 1) << 7) + j;
	keysym = keymap[j];
	if (KTYP(keysym) == (KT_LATIN \| 0xf0) \|\|
	KTYP(keysym) == (KT_LETTER \| 0xf0))
	ascebc[KVAL(keysym)] = k;
	else if (KTYP(keysym) == (KT_DEAD \| 0xf0))
	ascebc[ret_diacr[KVAL(keysym)]] = k;
	}
	}
	}

	#if 0
	/*
	* Generate ebcdic -> ascii translation table from kbd_data.
	*/
	void
	kbd_ebcasc(struct kbd_data kbd, unsigned char ebcasc)
	{
	unsigned short *keymap, keysym;
	int i, j, k;

	memset(ebcasc, ' ', 256);
	for (i = 0; i < ARRAY_SIZE(key_maps); i++) {
	keymap = kbd->key_maps[i];
	if (!keymap)
	continue;
	for (j = 0; j < NR_KEYS; j++) {
	keysym = keymap[j];
	k = ((i & 1) << 7) + j;
	if (KTYP(keysym) == (KT_LATIN \| 0xf0) \|\|
	KTYP(keysym) == (KT_LETTER \| 0xf0))
	ebcasc[k] = KVAL(keysym);
	else if (KTYP(keysym) == (KT_DEAD \| 0xf0))
	ebcasc[k] = ret_diacr[KVAL(keysym)];
	}
	}
	}
	#endif

	/*
	* We have a combining character DIACR here, followed by the character CH.
	* If the combination occurs in the table, return the corresponding value.
	* Otherwise, if CH is a space or equals DIACR, return DIACR.
	* Otherwise, conclude that DIACR was not combining after all,
	* queue it and return CH.
	*/
	static unsigned int
	handle_diacr(struct kbd_data *kbd, unsigned int ch)
	{
	int i, d;

	d = kbd->diacr;
	kbd->diacr = 0;

	for (i = 0; i < kbd->accent_table_size; i++) {
	if (kbd->accent_table[i].diacr == d &&
	kbd->accent_table[i].base == ch)
	return kbd->accent_table[i].result;
	}

	if (ch == ' ' \|\| ch == d)
	return d;

	kbd_put_queue(kbd->port, d);
	return ch;
	}

	/*
	* Handle dead key.
	*/
	static void
	k_dead(struct kbd_data *kbd, unsigned char value)
	{
	value = ret_diacr[value];
	kbd->diacr = (kbd->diacr ? handle_diacr(kbd, value) : value);
	}

	/*
	* Normal character handler.
	*/
	static void
	k_self(struct kbd_data *kbd, unsigned char value)
	{
	if (kbd->diacr)
	value = handle_diacr(kbd, value);
	kbd_put_queue(kbd->port, value);
	}

	/*
	* Special key handlers
	*/
	static void
	k_ignore(struct kbd_data *kbd, unsigned char value)
	{
	}

	/*
	* Function key handler.
	*/
	static void
	k_fn(struct kbd_data *kbd, unsigned char value)
	{
	if (kbd->func_table[value])
	kbd_puts_queue(kbd->port, kbd->func_table[value]);
	}

	static void
	k_spec(struct kbd_data *kbd, unsigned char value)
	{
	if (value >= NR_FN_HANDLER)
	return;
	if (kbd->fn_handler[value])
	kbd->fn_handler[value](kbd);
	}

	/*
	* Put utf8 character to tty flip buffer.
	* UTF-8 is defined for words of up to 31 bits,
	* but we need only 16 bits here
	*/
	static void
	to_utf8(struct tty_port *port, ushort c)
	{
	if (c < 0x80)
	/* 0******* */
	kbd_put_queue(port, c);
	else if (c < 0x800) {
	/* 110*** 10**** */
	kbd_put_queue(port, 0xc0 \| (c >> 6));
	kbd_put_queue(port, 0x80 \| (c & 0x3f));
	} else {
	/* 1110** 10** 10**** */
	kbd_put_queue(port, 0xe0 \| (c >> 12));
	kbd_put_queue(port, 0x80 \| ((c >> 6) & 0x3f));
	kbd_put_queue(port, 0x80 \| (c & 0x3f));
	}
	}

	/*
	* Process keycode.
	*/
	void
	kbd_keycode(struct kbd_data *kbd, unsigned int keycode)
	{
	unsigned short keysym;
	unsigned char type, value;

	if (!kbd)
	return;

	if (keycode >= 384)
	keysym = kbd->key_maps[5][keycode - 384];
	else if (keycode >= 256)
	keysym = kbd->key_maps[4][keycode - 256];
	else if (keycode >= 128)
	keysym = kbd->key_maps[1][keycode - 128];
	else
	keysym = kbd->key_maps[0][keycode];

	type = KTYP(keysym);
	if (type >= 0xf0) {
	type -= 0xf0;
	if (type == KT_LETTER)
	type = KT_LATIN;
	value = KVAL(keysym);
	#ifdef CONFIG_MAGIC_SYSRQ /* Handle the SysRq Hack */
	if (kbd->sysrq) {
	if (kbd->sysrq == K(KT_LATIN, '-')) {
	kbd->sysrq = 0;
	handle_sysrq(value);
	return;
	}
	if (value == '-') {
	kbd->sysrq = K(KT_LATIN, '-');
	return;
	}
	/* Incomplete sysrq sequence. */
	(*k_handler[KTYP(kbd->sysrq)])(kbd, KVAL(kbd->sysrq));
	kbd->sysrq = 0;
	} else if ((type == KT_LATIN && value == '^') \|\|
	(type == KT_DEAD && ret_diacr[value] == '^')) {
	kbd->sysrq = K(type, value);
	return;
	}
	#endif
	(*k_handler[type])(kbd, value);
	} else
	to_utf8(kbd->port, keysym);
	}

	/*
	* Ioctl stuff.
	*/
	static int
	do_kdsk_ioctl(struct kbd_data kbd, struct kbentry __user user_kbe,
	int cmd, int perm)
	{
	struct kbentry tmp;
	ushort *key_map, val, ov;

	if (copy_from_user(&tmp, user_kbe, sizeof(struct kbentry)))
	return -EFAULT;
	#if NR_KEYS < 256
	if (tmp.kb_index >= NR_KEYS)
	return -EINVAL;
	#endif
	#if MAX_NR_KEYMAPS < 256
	if (tmp.kb_table >= MAX_NR_KEYMAPS)
	return -EINVAL;
	#endif

	switch (cmd) {
	case KDGKBENT:
	key_map = kbd->key_maps[tmp.kb_table];
	if (key_map) {
	val = U(key_map[tmp.kb_index]);
	if (KTYP(val) >= KBD_NR_TYPES)
	val = K_HOLE;
	} else
	val = (tmp.kb_index ? K_HOLE : K_NOSUCHMAP);
	return put_user(val, &user_kbe->kb_value);
	case KDSKBENT:
	if (!perm)
	return -EPERM;
	if (!tmp.kb_index && tmp.kb_value == K_NOSUCHMAP) {
	/* disallocate map */
	key_map = kbd->key_maps[tmp.kb_table];
	if (key_map) {
	kbd->key_maps[tmp.kb_table] = NULL;
	kfree(key_map);
	}
	break;
	}

	if (KTYP(tmp.kb_value) >= KBD_NR_TYPES)
	return -EINVAL;
	if (KVAL(tmp.kb_value) > kbd_max_vals[KTYP(tmp.kb_value)])
	return -EINVAL;

	if (!(key_map = kbd->key_maps[tmp.kb_table])) {
	int j;

	key_map = kmalloc(sizeof(plain_map),
	GFP_KERNEL);
	if (!key_map)
	return -ENOMEM;
	kbd->key_maps[tmp.kb_table] = key_map;
	for (j = 0; j < NR_KEYS; j++)
	key_map[j] = U(K_HOLE);
	}
	ov = U(key_map[tmp.kb_index]);
	if (tmp.kb_value == ov)
	break; /* nothing to do */
	/*
	* Attention Key.
	*/
	if (((ov == K_SAK) \|\| (tmp.kb_value == K_SAK)) &&
	!capable(CAP_SYS_ADMIN))
	return -EPERM;
	key_map[tmp.kb_index] = U(tmp.kb_value);
	break;
	}
	return 0;
	}

	static int
	do_kdgkb_ioctl(struct kbd_data kbd, struct kbsentry __user u_kbs,
	int cmd, int perm)
	{
	unsigned char kb_func;
	char *p;
	int len;

	/* Get u_kbs->kb_func. */
	if (get_user(kb_func, &u_kbs->kb_func))
	return -EFAULT;
	#if MAX_NR_FUNC < 256
	if (kb_func >= MAX_NR_FUNC)
	return -EINVAL;
	#endif

	switch (cmd) {
	case KDGKBSENT:
	p = kbd->func_table[kb_func];
	if (p) {
	len = strlen(p);
	if (len >= sizeof(u_kbs->kb_string))
	len = sizeof(u_kbs->kb_string) - 1;
	if (copy_to_user(u_kbs->kb_string, p, len))
	return -EFAULT;
	} else
	len = 0;
	if (put_user('\0', u_kbs->kb_string + len))
	return -EFAULT;
	break;
	case KDSKBSENT:
	if (!perm)
	return -EPERM;
	len = strnlen_user(u_kbs->kb_string,
	sizeof(u_kbs->kb_string) - 1);
	if (!len)
	return -EFAULT;
	if (len > sizeof(u_kbs->kb_string) - 1)
	return -EINVAL;
	p = kmalloc(len + 1, GFP_KERNEL);
	if (!p)
	return -ENOMEM;
	if (copy_from_user(p, u_kbs->kb_string, len)) {
	kfree(p);
	return -EFAULT;
	}
	p[len] = 0;
	kfree(kbd->func_table[kb_func]);
	kbd->func_table[kb_func] = p;
	break;
	}
	return 0;
	}

	int kbd_ioctl(struct kbd_data *kbd, unsigned int cmd, unsigned long arg)
	{
	struct tty_struct *tty;
	void __user *argp;
	unsigned int ct;
	int perm;

	argp = (void __user *)arg;

	/*
	* To have permissions to do most of the vt ioctls, we either have
	* to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
	*/
	tty = tty_port_tty_get(kbd->port);
	/* FIXME this test is pretty racy */
	perm = current->signal->tty == tty \|\| capable(CAP_SYS_TTY_CONFIG);
	tty_kref_put(tty);
	switch (cmd) {
	case KDGKBTYPE:
	return put_user(KB_101, (char __user *)argp);
	case KDGKBENT:
	case KDSKBENT:
	return do_kdsk_ioctl(kbd, argp, cmd, perm);
	case KDGKBSENT:
	case KDSKBSENT:
	return do_kdgkb_ioctl(kbd, argp, cmd, perm);
	case KDGKBDIACR:
	{
	struct kbdiacrs __user *a = argp;
	struct kbdiacr diacr;
	int i;

	if (put_user(kbd->accent_table_size, &a->kb_cnt))
	return -EFAULT;
	for (i = 0; i < kbd->accent_table_size; i++) {
	diacr.diacr = kbd->accent_table[i].diacr;
	diacr.base = kbd->accent_table[i].base;
	diacr.result = kbd->accent_table[i].result;
	if (copy_to_user(a->kbdiacr + i, &diacr, sizeof(struct kbdiacr)))
	return -EFAULT;
	}
	return 0;
	}
	case KDGKBDIACRUC:
	{
	struct kbdiacrsuc __user *a = argp;

	ct = kbd->accent_table_size;
	if (put_user(ct, &a->kb_cnt))
	return -EFAULT;
	if (copy_to_user(a->kbdiacruc, kbd->accent_table,
	ct * sizeof(struct kbdiacruc)))
	return -EFAULT;
	return 0;
	}
	case KDSKBDIACR:
	{
	struct kbdiacrs __user *a = argp;
	struct kbdiacr diacr;
	int i;

	if (!perm)
	return -EPERM;
	if (get_user(ct, &a->kb_cnt))
	return -EFAULT;
	if (ct >= MAX_DIACR)
	return -EINVAL;
	kbd->accent_table_size = ct;
	for (i = 0; i < ct; i++) {
	if (copy_from_user(&diacr, a->kbdiacr + i, sizeof(struct kbdiacr)))
	return -EFAULT;
	kbd->accent_table[i].diacr = diacr.diacr;
	kbd->accent_table[i].base = diacr.base;
	kbd->accent_table[i].result = diacr.result;
	}
	return 0;
	}
	case KDSKBDIACRUC:
	{
	struct kbdiacrsuc __user *a = argp;

	if (!perm)
	return -EPERM;
	if (get_user(ct, &a->kb_cnt))
	return -EFAULT;
	if (ct >= MAX_DIACR)
	return -EINVAL;
	kbd->accent_table_size = ct;
	if (copy_from_user(kbd->accent_table, a->kbdiacruc,
	ct * sizeof(struct kbdiacruc)))
	return -EFAULT;
	return 0;
	}
	default:
	return -ENOIOCTLCMD;
	}
	}

	EXPORT_SYMBOL(kbd_ioctl);
	EXPORT_SYMBOL(kbd_ascebc);
	EXPORT_SYMBOL(kbd_free);
	EXPORT_SYMBOL(kbd_alloc);
	EXPORT_SYMBOL(kbd_keycode);