root/drivers/tty/vt/keyboard.c
// SPDX-License-Identifier: GPL-2.0
/*
 * Written for linux by Johan Myreen as a translation from
 * the assembly version by Linus (with diacriticals added)
 *
 * Some additional features added by Christoph Niemann (ChN), March 1993
 *
 * Loadable keymaps by Risto Kankkunen, May 1993
 *
 * Diacriticals redone & other small changes, aeb@cwi.nl, June 1993
 * Added decr/incr_console, dynamic keymaps, Unicode support,
 * dynamic function/string keys, led setting,  Sept 1994
 * `Sticky' modifier keys, 951006.
 *
 * 11-11-96: SAK should now work in the raw mode (Martin Mares)
 *
 * Modified to provide 'generic' keyboard support by Hamish Macdonald
 * Merge with the m68k keyboard driver and split-off of the PC low-level
 * parts by Geert Uytterhoeven, May 1997
 *
 * 27-05-97: Added support for the Magic SysRq Key (Martin Mares)
 * 30-07-98: Dead keys redone, aeb@cwi.nl.
 * 21-08-02: Converted to input API, major cleanup. (Vojtech Pavlik)
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/consolemap.h>
#include <linux/init.h>
#include <linux/input.h>
#include <linux/jiffies.h>
#include <linux/kbd_diacr.h>
#include <linux/kbd_kern.h>
#include <linux/leds.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/nospec.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/sched/debug.h>
#include <linux/sched/signal.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/tty_flip.h>
#include <linux/tty.h>
#include <linux/uaccess.h>
#include <linux/vt_kern.h>

#include <asm/irq_regs.h>

/*
 * Exported functions/variables
 */

#define KBD_DEFMODE (BIT(VC_REPEAT) | BIT(VC_META))

#if defined(CONFIG_X86) || defined(CONFIG_PARISC)
#include <asm/kbdleds.h>
#else
static inline int kbd_defleds(void)
{
        return 0;
}
#endif

#define KBD_DEFLOCK 0

/*
 * Handler Tables.
 */

#define K_HANDLERS\
        k_self,         k_fn,           k_spec,         k_pad,\
        k_dead,         k_cons,         k_cur,          k_shift,\
        k_meta,         k_ascii,        k_lock,         k_lowercase,\
        k_slock,        k_dead2,        k_brl,          k_ignore

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

#define FN_HANDLERS\
        fn_null,        fn_enter,       fn_show_ptregs, fn_show_mem,\
        fn_show_state,  fn_send_intr,   fn_lastcons,    fn_caps_toggle,\
        fn_num,         fn_hold,        fn_scroll_forw, fn_scroll_back,\
        fn_boot_it,     fn_caps_on,     fn_compose,     fn_SAK,\
        fn_dec_console, fn_inc_console, fn_spawn_con,   fn_bare_num

typedef void (fn_handler_fn)(struct vc_data *vc);
static fn_handler_fn FN_HANDLERS;
static fn_handler_fn *fn_handler[] = { FN_HANDLERS };

/*
 * Variables exported for vt_ioctl.c
 */

struct vt_spawn_console vt_spawn_con = {
        .lock = __SPIN_LOCK_UNLOCKED(vt_spawn_con.lock),
        .pid  = NULL,
        .sig  = 0,
};


/*
 * Internal Data.
 */

static struct kbd_struct kbd_table[MAX_NR_CONSOLES];
static struct kbd_struct *kbd = kbd_table;

/* maximum values each key_handler can handle */
static const unsigned char max_vals[] = {
        [ KT_LATIN      ] = 255,
        [ KT_FN         ] = ARRAY_SIZE(func_table) - 1,
        [ KT_SPEC       ] = ARRAY_SIZE(fn_handler) - 1,
        [ KT_PAD        ] = NR_PAD - 1,
        [ KT_DEAD       ] = NR_DEAD - 1,
        [ KT_CONS       ] = 255,
        [ KT_CUR        ] = 3,
        [ KT_SHIFT      ] = NR_SHIFT - 1,
        [ KT_META       ] = 255,
        [ KT_ASCII      ] = NR_ASCII - 1,
        [ KT_LOCK       ] = NR_LOCK - 1,
        [ KT_LETTER     ] = 255,
        [ KT_SLOCK      ] = NR_LOCK - 1,
        [ KT_DEAD2      ] = 255,
        [ KT_BRL        ] = NR_BRL - 1,
};

static const int NR_TYPES = ARRAY_SIZE(max_vals);

static void kbd_bh(struct tasklet_struct *unused);
static DECLARE_TASKLET_DISABLED(keyboard_tasklet, kbd_bh);

static struct input_handler kbd_handler;
static DEFINE_SPINLOCK(kbd_event_lock);
static DEFINE_SPINLOCK(led_lock);
static DEFINE_SPINLOCK(func_buf_lock); /* guard 'func_buf'  and friends */
static DECLARE_BITMAP(key_down, KEY_CNT);       /* keyboard key bitmap */
static unsigned char shift_down[NR_SHIFT];              /* shift state counters.. */
static bool dead_key_next;

/* Handles a number being assembled on the number pad */
static bool npadch_active;
static unsigned int npadch_value;

static unsigned int diacr;
static bool rep;                        /* flag telling character repeat */

static int shift_state = 0;

static unsigned int ledstate = -1U;                     /* undefined */
static unsigned char ledioctl;
static bool vt_switch;

/*
 * Notifier list for console keyboard events
 */
static ATOMIC_NOTIFIER_HEAD(keyboard_notifier_list);

int register_keyboard_notifier(struct notifier_block *nb)
{
        return atomic_notifier_chain_register(&keyboard_notifier_list, nb);
}
EXPORT_SYMBOL_GPL(register_keyboard_notifier);

int unregister_keyboard_notifier(struct notifier_block *nb)
{
        return atomic_notifier_chain_unregister(&keyboard_notifier_list, nb);
}
EXPORT_SYMBOL_GPL(unregister_keyboard_notifier);

/*
 * Translation of scancodes to keycodes. We set them on only the first
 * keyboard in the list that accepts the scancode and keycode.
 * Explanation for not choosing the first attached keyboard anymore:
 *  USB keyboards for example have two event devices: one for all "normal"
 *  keys and one for extra function keys (like "volume up", "make coffee",
 *  etc.). So this means that scancodes for the extra function keys won't
 *  be valid for the first event device, but will be for the second.
 */

struct getset_keycode_data {
        struct input_keymap_entry ke;
        int error;
};

static int getkeycode_helper(struct input_handle *handle, void *data)
{
        struct getset_keycode_data *d = data;

        d->error = input_get_keycode(handle->dev, &d->ke);

        return d->error == 0; /* stop as soon as we successfully get one */
}

static int getkeycode(unsigned int scancode)
{
        struct getset_keycode_data d = {
                .ke     = {
                        .flags          = 0,
                        .len            = sizeof(scancode),
                        .keycode        = 0,
                },
                .error  = -ENODEV,
        };

        memcpy(d.ke.scancode, &scancode, sizeof(scancode));

        input_handler_for_each_handle(&kbd_handler, &d, getkeycode_helper);

        return d.error ?: d.ke.keycode;
}

static int setkeycode_helper(struct input_handle *handle, void *data)
{
        struct getset_keycode_data *d = data;

        d->error = input_set_keycode(handle->dev, &d->ke);

        return d->error == 0; /* stop as soon as we successfully set one */
}

static int setkeycode(unsigned int scancode, unsigned int keycode)
{
        struct getset_keycode_data d = {
                .ke     = {
                        .flags          = 0,
                        .len            = sizeof(scancode),
                        .keycode        = keycode,
                },
                .error  = -ENODEV,
        };

        memcpy(d.ke.scancode, &scancode, sizeof(scancode));

        input_handler_for_each_handle(&kbd_handler, &d, setkeycode_helper);

        return d.error;
}

/*
 * Making beeps and bells. Note that we prefer beeps to bells, but when
 * shutting the sound off we do both.
 */

static int kd_sound_helper(struct input_handle *handle, void *data)
{
        unsigned int *hz = data;
        struct input_dev *dev = handle->dev;

        if (test_bit(EV_SND, dev->evbit)) {
                if (test_bit(SND_TONE, dev->sndbit)) {
                        input_inject_event(handle, EV_SND, SND_TONE, *hz);
                        if (*hz)
                                return 0;
                }
                if (test_bit(SND_BELL, dev->sndbit))
                        input_inject_event(handle, EV_SND, SND_BELL, *hz ? 1 : 0);
        }

        return 0;
}

static void kd_nosound(struct timer_list *unused)
{
        static unsigned int zero;

        input_handler_for_each_handle(&kbd_handler, &zero, kd_sound_helper);
}

static DEFINE_TIMER(kd_mksound_timer, kd_nosound);

void kd_mksound(unsigned int hz, unsigned int ticks)
{
        timer_delete_sync(&kd_mksound_timer);

        input_handler_for_each_handle(&kbd_handler, &hz, kd_sound_helper);

        if (hz && ticks)
                mod_timer(&kd_mksound_timer, jiffies + ticks);
}
EXPORT_SYMBOL(kd_mksound);

/*
 * Setting the keyboard rate.
 */

static int kbd_rate_helper(struct input_handle *handle, void *data)
{
        struct input_dev *dev = handle->dev;
        struct kbd_repeat *rpt = data;

        if (test_bit(EV_REP, dev->evbit)) {

                if (rpt[0].delay > 0)
                        input_inject_event(handle,
                                           EV_REP, REP_DELAY, rpt[0].delay);
                if (rpt[0].period > 0)
                        input_inject_event(handle,
                                           EV_REP, REP_PERIOD, rpt[0].period);

                rpt[1].delay = dev->rep[REP_DELAY];
                rpt[1].period = dev->rep[REP_PERIOD];
        }

        return 0;
}

int kbd_rate(struct kbd_repeat *rpt)
{
        struct kbd_repeat data[2] = { *rpt };

        input_handler_for_each_handle(&kbd_handler, data, kbd_rate_helper);
        *rpt = data[1]; /* Copy currently used settings */

        return 0;
}

/*
 * Helper Functions.
 */
static void put_queue(struct vc_data *vc, int ch)
{
        tty_insert_flip_char(&vc->port, ch, 0);
        tty_flip_buffer_push(&vc->port);
}

static void puts_queue(struct vc_data *vc, const char *cp)
{
        tty_insert_flip_string(&vc->port, cp, strlen(cp));
        tty_flip_buffer_push(&vc->port);
}

static void applkey(struct vc_data *vc, int key, char mode)
{
        static char buf[] = { 0x1b, 'O', 0x00, 0x00 };

        buf[1] = (mode ? 'O' : '[');
        buf[2] = key;
        puts_queue(vc, buf);
}

/*
 * Many other routines do put_queue, but I think either
 * they produce ASCII, or they produce some user-assigned
 * string, and in both cases we might assume that it is
 * in utf-8 already.
 */
static void to_utf8(struct vc_data *vc, uint c)
{
        if (c < 0x80)
                /*  0******* */
                put_queue(vc, c);
        else if (c < 0x800) {
                /* 110***** 10****** */
                put_queue(vc, 0xc0 | (c >> 6));
                put_queue(vc, 0x80 | (c & 0x3f));
        } else if (c < 0x10000) {
                if (c >= 0xD800 && c < 0xE000)
                        return;
                if (c == 0xFFFF)
                        return;
                /* 1110**** 10****** 10****** */
                put_queue(vc, 0xe0 | (c >> 12));
                put_queue(vc, 0x80 | ((c >> 6) & 0x3f));
                put_queue(vc, 0x80 | (c & 0x3f));
        } else if (c < 0x110000) {
                /* 11110*** 10****** 10****** 10****** */
                put_queue(vc, 0xf0 | (c >> 18));
                put_queue(vc, 0x80 | ((c >> 12) & 0x3f));
                put_queue(vc, 0x80 | ((c >> 6) & 0x3f));
                put_queue(vc, 0x80 | (c & 0x3f));
        }
}

static void put_queue_utf8(struct vc_data *vc, u32 value)
{
        if (kbd->kbdmode == VC_UNICODE)
                to_utf8(vc, value);
        else {
                int c = conv_uni_to_8bit(value);
                if (c != -1)
                        put_queue(vc, c);
        }
}

/* FIXME: review locking for vt.c callers */
static void set_leds(void)
{
        tasklet_schedule(&keyboard_tasklet);
}

/*
 * Called after returning from RAW mode or when changing consoles - recompute
 * shift_down[] and shift_state from key_down[] maybe called when keymap is
 * undefined, so that shiftkey release is seen. The caller must hold the
 * kbd_event_lock.
 */

static void do_compute_shiftstate(void)
{
        unsigned int k, sym, val;

        shift_state = 0;
        memset(shift_down, 0, sizeof(shift_down));

        for_each_set_bit(k, key_down, min(NR_KEYS, KEY_CNT)) {
                sym = U(key_maps[0][k]);
                if (KTYP(sym) != KT_SHIFT && KTYP(sym) != KT_SLOCK)
                        continue;

                val = KVAL(sym);
                if (val == KVAL(K_CAPSSHIFT))
                        val = KVAL(K_SHIFT);

                shift_down[val]++;
                shift_state |= BIT(val);
        }
}

/* We still have to export this method to vt.c */
void vt_set_leds_compute_shiftstate(void)
{
        /*
         * When VT is switched, the keyboard led needs to be set once.
         * Ensure that after the switch is completed, the state of the
         * keyboard LED is consistent with the state of the keyboard lock.
         */
        vt_switch = true;
        set_leds();

        guard(spinlock_irqsave)(&kbd_event_lock);
        do_compute_shiftstate();
}

/*
 * 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 vc_data *vc, unsigned int ch)
{
        unsigned int d = diacr;
        unsigned int i;

        diacr = 0;

        if ((d & ~0xff) == BRL_UC_ROW) {
                if ((ch & ~0xff) == BRL_UC_ROW)
                        return d | ch;
        } else {
                for (i = 0; i < accent_table_size; i++)
                        if (accent_table[i].diacr == d && accent_table[i].base == ch)
                                return accent_table[i].result;
        }

        if (ch == ' ' || ch == (BRL_UC_ROW|0) || ch == d)
                return d;

        put_queue_utf8(vc, d);

        return ch;
}

/*
 * Special function handlers
 */
static void fn_enter(struct vc_data *vc)
{
        if (diacr) {
                put_queue_utf8(vc, diacr);
                diacr = 0;
        }

        put_queue(vc, '\r');
        if (vc_kbd_mode(kbd, VC_CRLF))
                put_queue(vc, '\n');
}

static void fn_caps_toggle(struct vc_data *vc)
{
        if (rep)
                return;

        chg_vc_kbd_led(kbd, VC_CAPSLOCK);
}

static void fn_caps_on(struct vc_data *vc)
{
        if (rep)
                return;

        set_vc_kbd_led(kbd, VC_CAPSLOCK);
}

static void fn_show_ptregs(struct vc_data *vc)
{
        struct pt_regs *regs = get_irq_regs();

        if (regs)
                show_regs(regs);
}

static void fn_hold(struct vc_data *vc)
{
        struct tty_struct *tty = vc->port.tty;

        if (rep || !tty)
                return;

        /*
         * Note: SCROLLOCK will be set (cleared) by stop_tty (start_tty);
         * these routines are also activated by ^S/^Q.
         * (And SCROLLOCK can also be set by the ioctl KDSKBLED.)
         */
        if (tty->flow.stopped)
                start_tty(tty);
        else
                stop_tty(tty);
}

static void fn_num(struct vc_data *vc)
{
        if (vc_kbd_mode(kbd, VC_APPLIC))
                applkey(vc, 'P', 1);
        else
                fn_bare_num(vc);
}

/*
 * Bind this to Shift-NumLock if you work in application keypad mode
 * but want to be able to change the NumLock flag.
 * Bind this to NumLock if you prefer that the NumLock key always
 * changes the NumLock flag.
 */
static void fn_bare_num(struct vc_data *vc)
{
        if (!rep)
                chg_vc_kbd_led(kbd, VC_NUMLOCK);
}

static void fn_lastcons(struct vc_data *vc)
{
        /* switch to the last used console, ChN */
        set_console(last_console);
}

static void fn_dec_console(struct vc_data *vc)
{
        int i, cur = fg_console;

        /* Currently switching?  Queue this next switch relative to that. */
        if (want_console != -1)
                cur = want_console;

        for (i = cur - 1; i != cur; i--) {
                if (i == -1)
                        i = MAX_NR_CONSOLES - 1;
                if (vc_cons_allocated(i))
                        break;
        }
        set_console(i);
}

static void fn_inc_console(struct vc_data *vc)
{
        int i, cur = fg_console;

        /* Currently switching?  Queue this next switch relative to that. */
        if (want_console != -1)
                cur = want_console;

        for (i = cur+1; i != cur; i++) {
                if (i == MAX_NR_CONSOLES)
                        i = 0;
                if (vc_cons_allocated(i))
                        break;
        }
        set_console(i);
}

static void fn_send_intr(struct vc_data *vc)
{
        tty_insert_flip_char(&vc->port, 0, TTY_BREAK);
        tty_flip_buffer_push(&vc->port);
}

static void fn_scroll_forw(struct vc_data *vc)
{
        scrollfront(vc, 0);
}

static void fn_scroll_back(struct vc_data *vc)
{
        scrollback(vc);
}

static void fn_show_mem(struct vc_data *vc)
{
        show_mem();
}

static void fn_show_state(struct vc_data *vc)
{
        show_state();
}

static void fn_boot_it(struct vc_data *vc)
{
        ctrl_alt_del();
}

static void fn_compose(struct vc_data *vc)
{
        dead_key_next = true;
}

static void fn_spawn_con(struct vc_data *vc)
{
        guard(spinlock)(&vt_spawn_con.lock);
        if (vt_spawn_con.pid)
                if (kill_pid(vt_spawn_con.pid, vt_spawn_con.sig, 1)) {
                        put_pid(vt_spawn_con.pid);
                        vt_spawn_con.pid = NULL;
                }
}

static void fn_SAK(struct vc_data *vc)
{
        struct work_struct *SAK_work = &vc_cons[fg_console].SAK_work;
        schedule_work(SAK_work);
}

static void fn_null(struct vc_data *vc)
{
        do_compute_shiftstate();
}

/*
 * Special key handlers
 */
static void k_ignore(struct vc_data *vc, unsigned char value, char up_flag)
{
}

static void k_spec(struct vc_data *vc, unsigned char value, char up_flag)
{
        if (up_flag)
                return;
        if (value >= ARRAY_SIZE(fn_handler))
                return;
        if ((kbd->kbdmode == VC_RAW ||
             kbd->kbdmode == VC_MEDIUMRAW ||
             kbd->kbdmode == VC_OFF) &&
             value != KVAL(K_SAK))
                return;         /* SAK is allowed even in raw mode */
        fn_handler[value](vc);
}

static void k_lowercase(struct vc_data *vc, unsigned char value, char up_flag)
{
        pr_err("k_lowercase was called - impossible\n");
}

static void k_unicode(struct vc_data *vc, unsigned int value, char up_flag)
{
        if (up_flag)
                return;         /* no action, if this is a key release */

        if (diacr)
                value = handle_diacr(vc, value);

        if (dead_key_next) {
                dead_key_next = false;
                diacr = value;
                return;
        }
        put_queue_utf8(vc, value);
}

/*
 * Handle dead key. Note that we now may have several
 * dead keys modifying the same character. Very useful
 * for Vietnamese.
 */
static void k_deadunicode(struct vc_data *vc, unsigned int value, char up_flag)
{
        if (up_flag)
                return;

        diacr = (diacr ? handle_diacr(vc, value) : value);
}

static void k_self(struct vc_data *vc, unsigned char value, char up_flag)
{
        k_unicode(vc, conv_8bit_to_uni(value), up_flag);
}

static void k_dead2(struct vc_data *vc, unsigned char value, char up_flag)
{
        k_deadunicode(vc, value, up_flag);
}

/*
 * Obsolete - for backwards compatibility only
 */
static void k_dead(struct vc_data *vc, unsigned char value, char up_flag)
{
        static const unsigned char ret_diacr[NR_DEAD] = {
                '`',    /* dead_grave */
                '\'',   /* dead_acute */
                '^',    /* dead_circumflex */
                '~',    /* dead_tilda */
                '"',    /* dead_diaeresis */
                ',',    /* dead_cedilla */
                '_',    /* dead_macron */
                'U',    /* dead_breve */
                '.',    /* dead_abovedot */
                '*',    /* dead_abovering */
                '=',    /* dead_doubleacute */
                'c',    /* dead_caron */
                'k',    /* dead_ogonek */
                'i',    /* dead_iota */
                '#',    /* dead_voiced_sound */
                'o',    /* dead_semivoiced_sound */
                '!',    /* dead_belowdot */
                '?',    /* dead_hook */
                '+',    /* dead_horn */
                '-',    /* dead_stroke */
                ')',    /* dead_abovecomma */
                '(',    /* dead_abovereversedcomma */
                ':',    /* dead_doublegrave */
                'n',    /* dead_invertedbreve */
                ';',    /* dead_belowcomma */
                '$',    /* dead_currency */
                '@',    /* dead_greek */
        };

        k_deadunicode(vc, ret_diacr[value], up_flag);
}

static void k_cons(struct vc_data *vc, unsigned char value, char up_flag)
{
        if (up_flag)
                return;

        set_console(value);
}

static void k_fn(struct vc_data *vc, unsigned char value, char up_flag)
{
        if (up_flag)
                return;

        if ((unsigned)value < ARRAY_SIZE(func_table)) {
                guard(spinlock_irqsave)(&func_buf_lock);
                if (func_table[value])
                        puts_queue(vc, func_table[value]);
        } else
                pr_err("k_fn called with value=%d\n", value);
}

static void k_cur(struct vc_data *vc, unsigned char value, char up_flag)
{
        static const char cur_chars[] = "BDCA";

        if (up_flag)
                return;

        applkey(vc, cur_chars[value], vc_kbd_mode(kbd, VC_CKMODE));
}

static void k_pad(struct vc_data *vc, unsigned char value, char up_flag)
{
        static const char pad_chars[] = "0123456789+-*/\015,.?()#";
        static const char app_map[] = "pqrstuvwxylSRQMnnmPQS";

        if (up_flag)
                return;         /* no action, if this is a key release */

        /* kludge... shift forces cursor/number keys */
        if (vc_kbd_mode(kbd, VC_APPLIC) && !shift_down[KG_SHIFT]) {
                applkey(vc, app_map[value], 1);
                return;
        }

        if (!vc_kbd_led(kbd, VC_NUMLOCK)) {

                switch (value) {
                case KVAL(K_PCOMMA):
                case KVAL(K_PDOT):
                        k_fn(vc, KVAL(K_REMOVE), 0);
                        return;
                case KVAL(K_P0):
                        k_fn(vc, KVAL(K_INSERT), 0);
                        return;
                case KVAL(K_P1):
                        k_fn(vc, KVAL(K_SELECT), 0);
                        return;
                case KVAL(K_P2):
                        k_cur(vc, KVAL(K_DOWN), 0);
                        return;
                case KVAL(K_P3):
                        k_fn(vc, KVAL(K_PGDN), 0);
                        return;
                case KVAL(K_P4):
                        k_cur(vc, KVAL(K_LEFT), 0);
                        return;
                case KVAL(K_P6):
                        k_cur(vc, KVAL(K_RIGHT), 0);
                        return;
                case KVAL(K_P7):
                        k_fn(vc, KVAL(K_FIND), 0);
                        return;
                case KVAL(K_P8):
                        k_cur(vc, KVAL(K_UP), 0);
                        return;
                case KVAL(K_P9):
                        k_fn(vc, KVAL(K_PGUP), 0);
                        return;
                case KVAL(K_P5):
                        applkey(vc, 'G', vc_kbd_mode(kbd, VC_APPLIC));
                        return;
                }
        }

        put_queue(vc, pad_chars[value]);
        if (value == KVAL(K_PENTER) && vc_kbd_mode(kbd, VC_CRLF))
                put_queue(vc, '\n');
}

static void k_shift(struct vc_data *vc, unsigned char value, char up_flag)
{
        int old_state = shift_state;

        if (rep)
                return;
        /*
         * Mimic typewriter:
         * a CapsShift key acts like Shift but undoes CapsLock
         */
        if (value == KVAL(K_CAPSSHIFT)) {
                value = KVAL(K_SHIFT);
                if (!up_flag)
                        clr_vc_kbd_led(kbd, VC_CAPSLOCK);
        }

        if (up_flag) {
                /*
                 * handle the case that two shift or control
                 * keys are depressed simultaneously
                 */
                if (shift_down[value])
                        shift_down[value]--;
        } else
                shift_down[value]++;

        if (shift_down[value])
                shift_state |= BIT(value);
        else
                shift_state &= ~BIT(value);

        /* kludge */
        if (up_flag && shift_state != old_state && npadch_active) {
                if (kbd->kbdmode == VC_UNICODE)
                        to_utf8(vc, npadch_value);
                else
                        put_queue(vc, npadch_value & 0xff);
                npadch_active = false;
        }
}

static void k_meta(struct vc_data *vc, unsigned char value, char up_flag)
{
        if (up_flag)
                return;

        if (vc_kbd_mode(kbd, VC_META)) {
                put_queue(vc, '\033');
                put_queue(vc, value);
        } else
                put_queue(vc, value | BIT(7));
}

static void k_ascii(struct vc_data *vc, unsigned char value, char up_flag)
{
        unsigned int base;

        if (up_flag)
                return;

        if (value < 10) {
                /* decimal input of code, while Alt depressed */
                base = 10;
        } else {
                /* hexadecimal input of code, while AltGr depressed */
                value -= 10;
                base = 16;
        }

        if (!npadch_active) {
                npadch_value = 0;
                npadch_active = true;
        }

        npadch_value = npadch_value * base + value;
}

static void k_lock(struct vc_data *vc, unsigned char value, char up_flag)
{
        if (up_flag || rep)
                return;

        chg_vc_kbd_lock(kbd, value);
}

static void k_slock(struct vc_data *vc, unsigned char value, char up_flag)
{
        k_shift(vc, value, up_flag);
        if (up_flag || rep)
                return;

        chg_vc_kbd_slock(kbd, value);
        /* try to make Alt, oops, AltGr and such work */
        if (!key_maps[kbd->lockstate ^ kbd->slockstate]) {
                kbd->slockstate = 0;
                chg_vc_kbd_slock(kbd, value);
        }
}

/* by default, 300ms interval for combination release */
static unsigned brl_timeout = 300;
MODULE_PARM_DESC(brl_timeout, "Braille keys release delay in ms (0 for commit on first key release)");
module_param(brl_timeout, uint, 0644);

static unsigned brl_nbchords = 1;
MODULE_PARM_DESC(brl_nbchords, "Number of chords that produce a braille pattern (0 for dead chords)");
module_param(brl_nbchords, uint, 0644);

static void k_brlcommit(struct vc_data *vc, unsigned int pattern, char up_flag)
{
        static unsigned long chords;
        static unsigned committed;

        if (!brl_nbchords)
                k_deadunicode(vc, BRL_UC_ROW | pattern, up_flag);
        else {
                committed |= pattern;
                chords++;
                if (chords == brl_nbchords) {
                        k_unicode(vc, BRL_UC_ROW | committed, up_flag);
                        chords = 0;
                        committed = 0;
                }
        }
}

static void k_brl(struct vc_data *vc, unsigned char value, char up_flag)
{
        static unsigned pressed, committing;
        static unsigned long releasestart;

        if (kbd->kbdmode != VC_UNICODE) {
                if (!up_flag)
                        pr_warn("keyboard mode must be unicode for braille patterns\n");
                return;
        }

        if (!value) {
                k_unicode(vc, BRL_UC_ROW, up_flag);
                return;
        }

        if (value > 8)
                return;

        if (!up_flag) {
                pressed |= BIT(value - 1);
                if (!brl_timeout)
                        committing = pressed;
        } else if (brl_timeout) {
                if (!committing ||
                    time_after(jiffies,
                               releasestart + msecs_to_jiffies(brl_timeout))) {
                        committing = pressed;
                        releasestart = jiffies;
                }
                pressed &= ~BIT(value - 1);
                if (!pressed && committing) {
                        k_brlcommit(vc, committing, 0);
                        committing = 0;
                }
        } else {
                if (committing) {
                        k_brlcommit(vc, committing, 0);
                        committing = 0;
                }
                pressed &= ~BIT(value - 1);
        }
}

#if IS_ENABLED(CONFIG_INPUT_LEDS) && IS_ENABLED(CONFIG_LEDS_TRIGGERS)

struct kbd_led_trigger {
        struct led_trigger trigger;
        unsigned int mask;
};

static int kbd_led_trigger_activate(struct led_classdev *cdev)
{
        struct kbd_led_trigger *trigger =
                container_of(cdev->trigger, struct kbd_led_trigger, trigger);

        tasklet_disable(&keyboard_tasklet);
        if (ledstate != -1U)
                led_set_brightness(cdev, ledstate & trigger->mask ? LED_FULL : LED_OFF);
        tasklet_enable(&keyboard_tasklet);

        return 0;
}

#define KBD_LED_TRIGGER(_led_bit, _name) {                      \
                .trigger = {                                    \
                        .name = _name,                          \
                        .activate = kbd_led_trigger_activate,   \
                },                                              \
                .mask   = BIT(_led_bit),                        \
        }

#define KBD_LOCKSTATE_TRIGGER(_led_bit, _name)          \
        KBD_LED_TRIGGER((_led_bit) + 8, _name)

static struct kbd_led_trigger kbd_led_triggers[] = {
        KBD_LED_TRIGGER(VC_SCROLLOCK, "kbd-scrolllock"),
        KBD_LED_TRIGGER(VC_NUMLOCK,   "kbd-numlock"),
        KBD_LED_TRIGGER(VC_CAPSLOCK,  "kbd-capslock"),
        KBD_LED_TRIGGER(VC_KANALOCK,  "kbd-kanalock"),

        KBD_LOCKSTATE_TRIGGER(VC_SHIFTLOCK,  "kbd-shiftlock"),
        KBD_LOCKSTATE_TRIGGER(VC_ALTGRLOCK,  "kbd-altgrlock"),
        KBD_LOCKSTATE_TRIGGER(VC_CTRLLOCK,   "kbd-ctrllock"),
        KBD_LOCKSTATE_TRIGGER(VC_ALTLOCK,    "kbd-altlock"),
        KBD_LOCKSTATE_TRIGGER(VC_SHIFTLLOCK, "kbd-shiftllock"),
        KBD_LOCKSTATE_TRIGGER(VC_SHIFTRLOCK, "kbd-shiftrlock"),
        KBD_LOCKSTATE_TRIGGER(VC_CTRLLLOCK,  "kbd-ctrlllock"),
        KBD_LOCKSTATE_TRIGGER(VC_CTRLRLOCK,  "kbd-ctrlrlock"),
};

static void kbd_propagate_led_state(unsigned int old_state,
                                    unsigned int new_state)
{
        struct kbd_led_trigger *trigger;
        unsigned int changed = old_state ^ new_state;
        int i;

        for (i = 0; i < ARRAY_SIZE(kbd_led_triggers); i++) {
                trigger = &kbd_led_triggers[i];

                if (changed & trigger->mask)
                        led_trigger_event(&trigger->trigger,
                                          new_state & trigger->mask ?
                                                LED_FULL : LED_OFF);
        }
}

static int kbd_update_leds_helper(struct input_handle *handle, void *data)
{
        unsigned int led_state = *(unsigned int *)data;

        if (test_bit(EV_LED, handle->dev->evbit))
                kbd_propagate_led_state(~led_state, led_state);

        return 0;
}

static void kbd_init_leds(void)
{
        int error;
        int i;

        for (i = 0; i < ARRAY_SIZE(kbd_led_triggers); i++) {
                error = led_trigger_register(&kbd_led_triggers[i].trigger);
                if (error)
                        pr_err("error %d while registering trigger %s\n",
                               error, kbd_led_triggers[i].trigger.name);
        }
}

#else

static int kbd_update_leds_helper(struct input_handle *handle, void *data)
{
        unsigned int leds = *(unsigned int *)data;

        if (test_bit(EV_LED, handle->dev->evbit)) {
                input_inject_event(handle, EV_LED, LED_SCROLLL, !!(leds & BIT(0)));
                input_inject_event(handle, EV_LED, LED_NUML,    !!(leds & BIT(1)));
                input_inject_event(handle, EV_LED, LED_CAPSL,   !!(leds & BIT(2)));
                input_inject_event(handle, EV_SYN, SYN_REPORT, 0);
        }

        return 0;
}

static void kbd_propagate_led_state(unsigned int old_state,
                                    unsigned int new_state)
{
        input_handler_for_each_handle(&kbd_handler, &new_state,
                                      kbd_update_leds_helper);
}

static void kbd_init_leds(void)
{
}

#endif

/*
 * The leds display either (i) the status of NumLock, CapsLock, ScrollLock,
 * or (ii) whatever pattern of lights people want to show using KDSETLED,
 * or (iii) specified bits of specified words in kernel memory.
 */
static unsigned char getledstate(void)
{
        return ledstate & 0xff;
}

void setledstate(struct kbd_struct *kb, unsigned int led)
{
        guard(spinlock_irqsave)(&led_lock);
        if (!(led & ~7)) {
                ledioctl = led;
                kb->ledmode = LED_SHOW_IOCTL;
        } else
                kb->ledmode = LED_SHOW_FLAGS;

        set_leds();
}

static inline unsigned char getleds(void)
{
        struct kbd_struct *kb = kbd_table + fg_console;

        if (kb->ledmode == LED_SHOW_IOCTL)
                return ledioctl;

        return kb->ledflagstate;
}

/**
 *      vt_get_leds     -       helper for braille console
 *      @console: console to read
 *      @flag: flag we want to check
 *
 *      Check the status of a keyboard led flag and report it back
 */
int vt_get_leds(unsigned int console, int flag)
{
        struct kbd_struct *kb = &kbd_table[console];

        guard(spinlock_irqsave)(&led_lock);
        return vc_kbd_led(kb, flag);
}
EXPORT_SYMBOL_GPL(vt_get_leds);

/**
 *      vt_set_led_state        -       set LED state of a console
 *      @console: console to set
 *      @leds: LED bits
 *
 *      Set the LEDs on a console. This is a wrapper for the VT layer
 *      so that we can keep kbd knowledge internal
 */
void vt_set_led_state(unsigned int console, int leds)
{
        struct kbd_struct *kb = &kbd_table[console];
        setledstate(kb, leds);
}

/**
 *      vt_kbd_con_start        -       Keyboard side of console start
 *      @console: console
 *
 *      Handle console start. This is a wrapper for the VT layer
 *      so that we can keep kbd knowledge internal
 *
 *      FIXME: We eventually need to hold the kbd lock here to protect
 *      the LED updating. We can't do it yet because fn_hold calls stop_tty
 *      and start_tty under the kbd_event_lock, while normal tty paths
 *      don't hold the lock. We probably need to split out an LED lock
 *      but not during an -rc release!
 */
void vt_kbd_con_start(unsigned int console)
{
        struct kbd_struct *kb = &kbd_table[console];

        guard(spinlock_irqsave)(&led_lock);
        clr_vc_kbd_led(kb, VC_SCROLLOCK);
        set_leds();
}

/**
 *      vt_kbd_con_stop         -       Keyboard side of console stop
 *      @console: console
 *
 *      Handle console stop. This is a wrapper for the VT layer
 *      so that we can keep kbd knowledge internal
 */
void vt_kbd_con_stop(unsigned int console)
{
        struct kbd_struct *kb = &kbd_table[console];

        guard(spinlock_irqsave)(&led_lock);
        set_vc_kbd_led(kb, VC_SCROLLOCK);
        set_leds();
}

/*
 * This is the tasklet that updates LED state of LEDs using standard
 * keyboard triggers. The reason we use tasklet is that we need to
 * handle the scenario when keyboard handler is not registered yet
 * but we already getting updates from the VT to update led state.
 */
static void kbd_bh(struct tasklet_struct *unused)
{
        unsigned int leds;

        scoped_guard(spinlock_irqsave, &led_lock) {
                leds = getleds();
                leds |= (unsigned int)kbd->lockstate << 8;
        }

        if (vt_switch) {
                ledstate = ~leds;
                vt_switch = false;
        }

        if (leds != ledstate) {
                kbd_propagate_led_state(ledstate, leds);
                ledstate = leds;
        }
}

#if defined(CONFIG_X86) || defined(CONFIG_ALPHA) ||\
    defined(CONFIG_MIPS) || defined(CONFIG_PPC) || defined(CONFIG_SPARC) ||\
    defined(CONFIG_PARISC) || defined(CONFIG_SUPERH) ||\
    (defined(CONFIG_ARM) && defined(CONFIG_KEYBOARD_ATKBD) && !defined(CONFIG_ARCH_RPC))

static inline bool kbd_is_hw_raw(const struct input_dev *dev)
{
        if (!test_bit(EV_MSC, dev->evbit) || !test_bit(MSC_RAW, dev->mscbit))
                return false;

        return dev->id.bustype == BUS_I8042 &&
                dev->id.vendor == 0x0001 && dev->id.product == 0x0001;
}

static const unsigned short x86_keycodes[256] =
        { 0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15,
         16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
         32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47,
         48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63,
         64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79,
         80, 81, 82, 83, 84,118, 86, 87, 88,115,120,119,121,112,123, 92,
        284,285,309,  0,312, 91,327,328,329,331,333,335,336,337,338,339,
        367,288,302,304,350, 89,334,326,267,126,268,269,125,347,348,349,
        360,261,262,263,268,376,100,101,321,316,373,286,289,102,351,355,
        103,104,105,275,287,279,258,106,274,107,294,364,358,363,362,361,
        291,108,381,281,290,272,292,305,280, 99,112,257,306,359,113,114,
        264,117,271,374,379,265,266, 93, 94, 95, 85,259,375,260, 90,116,
        377,109,111,277,278,282,283,295,296,297,299,300,301,293,303,307,
        308,310,313,314,315,317,318,319,320,357,322,323,324,325,276,330,
        332,340,365,342,343,344,345,346,356,270,341,368,369,370,371,372 };

#ifdef CONFIG_SPARC
static int sparc_l1_a_state;
extern void sun_do_break(void);
#endif

static int emulate_raw(struct vc_data *vc, unsigned int keycode,
                       unsigned char up_flag)
{
        int code;

        switch (keycode) {

        case KEY_PAUSE:
                put_queue(vc, 0xe1);
                put_queue(vc, 0x1d | up_flag);
                put_queue(vc, 0x45 | up_flag);
                break;

        case KEY_HANGEUL:
                if (!up_flag)
                        put_queue(vc, 0xf2);
                break;

        case KEY_HANJA:
                if (!up_flag)
                        put_queue(vc, 0xf1);
                break;

        case KEY_SYSRQ:
                /*
                 * Real AT keyboards (that's what we're trying
                 * to emulate here) emit 0xe0 0x2a 0xe0 0x37 when
                 * pressing PrtSc/SysRq alone, but simply 0x54
                 * when pressing Alt+PrtSc/SysRq.
                 */
                if (test_bit(KEY_LEFTALT, key_down) ||
                    test_bit(KEY_RIGHTALT, key_down)) {
                        put_queue(vc, 0x54 | up_flag);
                } else {
                        put_queue(vc, 0xe0);
                        put_queue(vc, 0x2a | up_flag);
                        put_queue(vc, 0xe0);
                        put_queue(vc, 0x37 | up_flag);
                }
                break;

        default:
                if (keycode > 255)
                        return -1;

                code = x86_keycodes[keycode];
                if (!code)
                        return -1;

                if (code & 0x100)
                        put_queue(vc, 0xe0);
                put_queue(vc, (code & 0x7f) | up_flag);

                break;
        }

        return 0;
}

#else

static inline bool kbd_is_hw_raw(const struct input_dev *dev)
{
        return false;
}

static int emulate_raw(struct vc_data *vc, unsigned int keycode, unsigned char up_flag)
{
        if (keycode > 127)
                return -1;

        put_queue(vc, keycode | up_flag);
        return 0;
}
#endif

static void kbd_rawcode(unsigned char data)
{
        struct vc_data *vc = vc_cons[fg_console].d;

        kbd = &kbd_table[vc->vc_num];
        if (kbd->kbdmode == VC_RAW)
                put_queue(vc, data);
}

static void kbd_keycode(unsigned int keycode, int down, bool hw_raw)
{
        struct vc_data *vc = vc_cons[fg_console].d;
        unsigned short keysym, *key_map;
        unsigned char type;
        bool raw_mode;
        struct tty_struct *tty;
        int shift_final;
        struct keyboard_notifier_param param = { .vc = vc, .value = keycode, .down = down };
        int rc;

        tty = vc->port.tty;

        if (tty && (!tty->driver_data)) {
                /* No driver data? Strange. Okay we fix it then. */
                tty->driver_data = vc;
        }

        kbd = &kbd_table[vc->vc_num];

#ifdef CONFIG_SPARC
        if (keycode == KEY_STOP)
                sparc_l1_a_state = down;
#endif

        rep = (down == 2);

        raw_mode = (kbd->kbdmode == VC_RAW);
        if (raw_mode && !hw_raw)
                if (emulate_raw(vc, keycode, !down << 7))
                        if (keycode < BTN_MISC && printk_ratelimit())
                                pr_warn("can't emulate rawmode for keycode %d\n",
                                        keycode);

#ifdef CONFIG_SPARC
        if (keycode == KEY_A && sparc_l1_a_state) {
                sparc_l1_a_state = false;
                sun_do_break();
        }
#endif

        if (kbd->kbdmode == VC_MEDIUMRAW) {
                /*
                 * This is extended medium raw mode, with keys above 127
                 * encoded as 0, high 7 bits, low 7 bits, with the 0 bearing
                 * the 'up' flag if needed. 0 is reserved, so this shouldn't
                 * interfere with anything else. The two bytes after 0 will
                 * always have the up flag set not to interfere with older
                 * applications. This allows for 16384 different keycodes,
                 * which should be enough.
                 */
                if (keycode < 128) {
                        put_queue(vc, keycode | (!down << 7));
                } else {
                        put_queue(vc, !down << 7);
                        put_queue(vc, (keycode >> 7) | BIT(7));
                        put_queue(vc, keycode | BIT(7));
                }
                raw_mode = true;
        }

        assign_bit(keycode, key_down, down);

        if (rep &&
            (!vc_kbd_mode(kbd, VC_REPEAT) ||
             (tty && !L_ECHO(tty) && tty_chars_in_buffer(tty)))) {
                /*
                 * Don't repeat a key if the input buffers are not empty and the
                 * characters get aren't echoed locally. This makes key repeat
                 * usable with slow applications and under heavy loads.
                 */
                return;
        }

        param.shift = shift_final = (shift_state | kbd->slockstate) ^ kbd->lockstate;
        param.ledstate = kbd->ledflagstate;
        key_map = key_maps[shift_final];

        rc = atomic_notifier_call_chain(&keyboard_notifier_list,
                                        KBD_KEYCODE, &param);
        if (rc == NOTIFY_STOP || !key_map) {
                atomic_notifier_call_chain(&keyboard_notifier_list,
                                           KBD_UNBOUND_KEYCODE, &param);
                do_compute_shiftstate();
                kbd->slockstate = 0;
                return;
        }

        if (keycode < NR_KEYS)
                keysym = key_map[keycode];
        else if (keycode >= KEY_BRL_DOT1 && keycode <= KEY_BRL_DOT8)
                keysym = U(K(KT_BRL, keycode - KEY_BRL_DOT1 + 1));
        else
                return;

        type = KTYP(keysym);

        if (type < 0xf0) {
                param.value = keysym;
                rc = atomic_notifier_call_chain(&keyboard_notifier_list,
                                                KBD_UNICODE, &param);
                if (rc != NOTIFY_STOP)
                        if (down && !(raw_mode || kbd->kbdmode == VC_OFF))
                                k_unicode(vc, keysym, !down);
                return;
        }

        type -= 0xf0;

        if (type == KT_LETTER) {
                type = KT_LATIN;
                if (vc_kbd_led(kbd, VC_CAPSLOCK)) {
                        key_map = key_maps[shift_final ^ BIT(KG_SHIFT)];
                        if (key_map)
                                keysym = key_map[keycode];
                }
        }

        param.value = keysym;
        rc = atomic_notifier_call_chain(&keyboard_notifier_list,
                                        KBD_KEYSYM, &param);
        if (rc == NOTIFY_STOP)
                return;

        if ((raw_mode || kbd->kbdmode == VC_OFF) && type != KT_SPEC && type != KT_SHIFT)
                return;

        (*k_handler[type])(vc, KVAL(keysym), !down);

        param.ledstate = kbd->ledflagstate;
        atomic_notifier_call_chain(&keyboard_notifier_list, KBD_POST_KEYSYM, &param);

        if (type != KT_SLOCK)
                kbd->slockstate = 0;
}

static void kbd_event(struct input_handle *handle, unsigned int event_type,
                      unsigned int event_code, int value)
{
        /* We are called with interrupts disabled, just take the lock */
        scoped_guard(spinlock, &kbd_event_lock) {
                if (event_type == EV_MSC && event_code == MSC_RAW &&
                                kbd_is_hw_raw(handle->dev))
                        kbd_rawcode(value);
                if (event_type == EV_KEY && event_code <= KEY_MAX)
                        kbd_keycode(event_code, value, kbd_is_hw_raw(handle->dev));
        }

        tasklet_schedule(&keyboard_tasklet);
        do_poke_blanked_console = 1;
        schedule_console_callback();
}

static bool kbd_match(struct input_handler *handler, struct input_dev *dev)
{
        if (test_bit(EV_SND, dev->evbit))
                return true;

        if (test_bit(EV_KEY, dev->evbit)) {
                if (find_next_bit(dev->keybit, BTN_MISC, KEY_RESERVED) <
                                BTN_MISC)
                        return true;
                if (find_next_bit(dev->keybit, KEY_BRL_DOT10 + 1,
                                        KEY_BRL_DOT1) <= KEY_BRL_DOT10)
                        return true;
        }

        return false;
}

/*
 * When a keyboard (or other input device) is found, the kbd_connect
 * function is called. The function then looks at the device, and if it
 * likes it, it can open it and get events from it. In this (kbd_connect)
 * function, we should decide which VT to bind that keyboard to initially.
 */
static int kbd_connect(struct input_handler *handler, struct input_dev *dev,
                        const struct input_device_id *id)
{
        int error;

        struct input_handle __free(kfree) *handle = kzalloc_obj(*handle);
        if (!handle)
                return -ENOMEM;

        handle->dev = dev;
        handle->handler = handler;
        handle->name = "kbd";

        error = input_register_handle(handle);
        if (error)
                return error;

        error = input_open_device(handle);
        if (error)
                goto err_unregister_handle;

        retain_and_null_ptr(handle);

        return 0;

 err_unregister_handle:
        input_unregister_handle(handle);
        return error;
}

static void kbd_disconnect(struct input_handle *handle)
{
        input_close_device(handle);
        input_unregister_handle(handle);
        kfree(handle);
}

/*
 * Start keyboard handler on the new keyboard by refreshing LED state to
 * match the rest of the system.
 */
static void kbd_start(struct input_handle *handle)
{
        tasklet_disable(&keyboard_tasklet);

        if (ledstate != -1U)
                kbd_update_leds_helper(handle, &ledstate);

        tasklet_enable(&keyboard_tasklet);
}

static const struct input_device_id kbd_ids[] = {
        {
                .flags = INPUT_DEVICE_ID_MATCH_EVBIT,
                .evbit = { BIT_MASK(EV_KEY) },
        },

        {
                .flags = INPUT_DEVICE_ID_MATCH_EVBIT,
                .evbit = { BIT_MASK(EV_SND) },
        },

        { },    /* Terminating entry */
};

MODULE_DEVICE_TABLE(input, kbd_ids);

static struct input_handler kbd_handler = {
        .event          = kbd_event,
        .match          = kbd_match,
        .connect        = kbd_connect,
        .disconnect     = kbd_disconnect,
        .start          = kbd_start,
        .name           = "kbd",
        .id_table       = kbd_ids,
};

int __init kbd_init(void)
{
        int i;
        int error;

        for (i = 0; i < MAX_NR_CONSOLES; i++) {
                kbd_table[i].ledflagstate = kbd_defleds();
                kbd_table[i].default_ledflagstate = kbd_defleds();
                kbd_table[i].ledmode = LED_SHOW_FLAGS;
                kbd_table[i].lockstate = KBD_DEFLOCK;
                kbd_table[i].slockstate = 0;
                kbd_table[i].modeflags = KBD_DEFMODE;
                kbd_table[i].kbdmode = default_utf8 ? VC_UNICODE : VC_XLATE;
        }

        kbd_init_leds();

        error = input_register_handler(&kbd_handler);
        if (error)
                return error;

        tasklet_enable(&keyboard_tasklet);
        tasklet_schedule(&keyboard_tasklet);

        return 0;
}

/* Ioctl support code */

static int vt_do_kdgkbdiacr(void __user *udp)
{
        struct kbdiacrs __user *a = udp;
        int i, asize;

        struct kbdiacr __free(kfree) *dia = kmalloc_array(MAX_DIACR, sizeof(struct kbdiacr),
                                                          GFP_KERNEL);
        if (!dia)
                return -ENOMEM;

        /* Lock the diacriticals table, make a copy and then
           copy it after we unlock */
        scoped_guard(spinlock_irqsave, &kbd_event_lock) {
                asize = accent_table_size;
                for (i = 0; i < asize; i++) {
                        dia[i].diacr = conv_uni_to_8bit(accent_table[i].diacr);
                        dia[i].base = conv_uni_to_8bit(accent_table[i].base);
                        dia[i].result = conv_uni_to_8bit(accent_table[i].result);
                }
        }

        if (put_user(asize, &a->kb_cnt))
                return -EFAULT;
        if (copy_to_user(a->kbdiacr, dia, asize * sizeof(struct kbdiacr)))
                return -EFAULT;
        return 0;
}

static int vt_do_kdgkbdiacruc(void __user *udp)
{
        struct kbdiacrsuc __user *a = udp;
        int asize;

        void __free(kfree) *buf = kmalloc_array(MAX_DIACR, sizeof(struct kbdiacruc),
                                                GFP_KERNEL);
        if (buf == NULL)
                return -ENOMEM;

        /* Lock the diacriticals table, make a copy and then
           copy it after we unlock */
        scoped_guard(spinlock_irqsave, &kbd_event_lock) {
                asize = accent_table_size;
                memcpy(buf, accent_table, asize * sizeof(struct kbdiacruc));
        }

        if (put_user(asize, &a->kb_cnt))
                return -EFAULT;
        if (copy_to_user(a->kbdiacruc, buf, asize * sizeof(struct kbdiacruc)))
                return -EFAULT;

        return 0;
}

static int vt_do_kdskbdiacr(void __user *udp, int perm)
{
        struct kbdiacrs __user *a = udp;
        struct kbdiacr __free(kfree) *dia = NULL;
        unsigned int ct;
        int i;

        if (!perm)
                return -EPERM;
        if (get_user(ct, &a->kb_cnt))
                return -EFAULT;
        if (ct >= MAX_DIACR)
                return -EINVAL;

        if (ct) {
                dia = memdup_array_user(a->kbdiacr,
                                        ct, sizeof(struct kbdiacr));
                if (IS_ERR(dia))
                        return PTR_ERR(dia);
        }

        guard(spinlock_irqsave)(&kbd_event_lock);
        accent_table_size = ct;
        for (i = 0; i < ct; i++) {
                accent_table[i].diacr =
                                conv_8bit_to_uni(dia[i].diacr);
                accent_table[i].base =
                                conv_8bit_to_uni(dia[i].base);
                accent_table[i].result =
                                conv_8bit_to_uni(dia[i].result);
        }

        return 0;
}

static int vt_do_kdskbdiacruc(void __user *udp, int perm)
{
        struct kbdiacrsuc __user *a = udp;
        unsigned int ct;
        void __free(kfree) *buf = NULL;

        if (!perm)
                return -EPERM;

        if (get_user(ct, &a->kb_cnt))
                return -EFAULT;

        if (ct >= MAX_DIACR)
                return -EINVAL;

        if (ct) {
                buf = memdup_array_user(a->kbdiacruc,
                                        ct, sizeof(struct kbdiacruc));
                if (IS_ERR(buf))
                        return PTR_ERR(buf);
        }
        guard(spinlock_irqsave)(&kbd_event_lock);
        if (ct)
                memcpy(accent_table, buf,
                                ct * sizeof(struct kbdiacruc));
        accent_table_size = ct;
        return 0;
}

/**
 *      vt_do_diacrit           -       diacritical table updates
 *      @cmd: ioctl request
 *      @udp: pointer to user data for ioctl
 *      @perm: permissions check computed by caller
 *
 *      Update the diacritical tables atomically and safely. Lock them
 *      against simultaneous keypresses
 */
int vt_do_diacrit(unsigned int cmd, void __user *udp, int perm)
{
        switch (cmd) {
        case KDGKBDIACR:
                return vt_do_kdgkbdiacr(udp);
        case KDGKBDIACRUC:
                return vt_do_kdgkbdiacruc(udp);
        case KDSKBDIACR:
                return vt_do_kdskbdiacr(udp, perm);
        case KDSKBDIACRUC:
                return vt_do_kdskbdiacruc(udp, perm);
        }
        return 0;
}

/**
 *      vt_do_kdskbmode         -       set keyboard mode ioctl
 *      @console: the console to use
 *      @arg: the requested mode
 *
 *      Update the keyboard mode bits while holding the correct locks.
 *      Return 0 for success or an error code.
 */
int vt_do_kdskbmode(unsigned int console, unsigned int arg)
{
        struct kbd_struct *kb = &kbd_table[console];

        guard(spinlock_irqsave)(&kbd_event_lock);
        switch(arg) {
        case K_RAW:
                kb->kbdmode = VC_RAW;
                return 0;
        case K_MEDIUMRAW:
                kb->kbdmode = VC_MEDIUMRAW;
                return 0;
        case K_XLATE:
                kb->kbdmode = VC_XLATE;
                do_compute_shiftstate();
                return 0;
        case K_UNICODE:
                kb->kbdmode = VC_UNICODE;
                do_compute_shiftstate();
                return 0;
        case K_OFF:
                kb->kbdmode = VC_OFF;
                return 0;
        default:
                return -EINVAL;
        }
}

/**
 *      vt_do_kdskbmeta         -       set keyboard meta state
 *      @console: the console to use
 *      @arg: the requested meta state
 *
 *      Update the keyboard meta bits while holding the correct locks.
 *      Return 0 for success or an error code.
 */
int vt_do_kdskbmeta(unsigned int console, unsigned int arg)
{
        struct kbd_struct *kb = &kbd_table[console];

        guard(spinlock_irqsave)(&kbd_event_lock);
        switch(arg) {
        case K_METABIT:
                clr_vc_kbd_mode(kb, VC_META);
                return 0;
        case K_ESCPREFIX:
                set_vc_kbd_mode(kb, VC_META);
                return 0;
        default:
                return -EINVAL;
        }
}

int vt_do_kbkeycode_ioctl(int cmd, struct kbkeycode __user *user_kbkc, int perm)
{
        struct kbkeycode tmp;
        int kc;

        if (copy_from_user(&tmp, user_kbkc, sizeof(struct kbkeycode)))
                return -EFAULT;

        switch (cmd) {
        case KDGETKEYCODE:
                kc = getkeycode(tmp.scancode);
                if (kc < 0)
                        return kc;
                return put_user(kc, &user_kbkc->keycode);
        case KDSETKEYCODE:
                if (!perm)
                        return -EPERM;
                return setkeycode(tmp.scancode, tmp.keycode);
        }

        return 0;
}

static unsigned short vt_kdgkbent(unsigned char kbdmode, unsigned char idx,
                unsigned char map)
{
        unsigned short *key_map;

        /* Ensure another thread doesn't free it under us */
        guard(spinlock_irqsave)(&kbd_event_lock);
        key_map = key_maps[map];
        if (key_map) {
                unsigned short val = U(key_map[idx]);
                if (kbdmode != VC_UNICODE && KTYP(val) >= NR_TYPES)
                        return K_HOLE;
                return val;
        }

        return idx ? K_HOLE : K_NOSUCHMAP;
}

static int vt_kdskbent(unsigned char kbdmode, unsigned char idx,
                unsigned char map, unsigned short val)
{
        unsigned short *key_map, oldval;

        if (!idx && val == K_NOSUCHMAP) {
                guard(spinlock_irqsave)(&kbd_event_lock);
                /* deallocate map */
                key_map = key_maps[map];
                if (map && key_map) {
                        key_maps[map] = NULL;
                        if (key_map[0] == U(K_ALLOCATED)) {
                                kfree(key_map);
                                keymap_count--;
                        }
                }

                return 0;
        }

        if (KTYP(val) < NR_TYPES) {
                if (KVAL(val) > max_vals[KTYP(val)])
                        return -EINVAL;
        } else if (kbdmode != VC_UNICODE)
                return -EINVAL;

        /* ++Geert: non-PC keyboards may generate keycode zero */
#if !defined(__mc68000__) && !defined(__powerpc__)
        /* assignment to entry 0 only tests validity of args */
        if (!idx)
                return 0;
#endif

        unsigned short __free(kfree) *new_map = kmalloc(sizeof(plain_map), GFP_KERNEL);
        if (!new_map)
                return -ENOMEM;

        guard(spinlock_irqsave)(&kbd_event_lock);
        key_map = key_maps[map];
        if (key_map == NULL) {
                int j;

                if (keymap_count >= MAX_NR_OF_USER_KEYMAPS && !capable(CAP_SYS_RESOURCE))
                        return -EPERM;

                key_map = key_maps[map] = no_free_ptr(new_map);
                key_map[0] = U(K_ALLOCATED);
                for (j = 1; j < NR_KEYS; j++)
                        key_map[j] = U(K_HOLE);
                keymap_count++;
        }

        oldval = U(key_map[idx]);
        if (val == oldval)
                return 0;

        /* Attention Key */
        if ((oldval == K_SAK || val == K_SAK) && !capable(CAP_SYS_ADMIN))
                return -EPERM;

        key_map[idx] = U(val);
        if (!map && (KTYP(oldval) == KT_SHIFT || KTYP(val) == KT_SHIFT))
                do_compute_shiftstate();

        return 0;
}

int vt_do_kdsk_ioctl(int cmd, struct kbentry __user *user_kbe, int perm,
                                                unsigned int console)
{
        struct kbd_struct *kb = &kbd_table[console];
        struct kbentry kbe;

        if (copy_from_user(&kbe, user_kbe, sizeof(struct kbentry)))
                return -EFAULT;

        switch (cmd) {
        case KDGKBENT:
                return put_user(vt_kdgkbent(kb->kbdmode, kbe.kb_index,
                                        kbe.kb_table),
                                &user_kbe->kb_value);
        case KDSKBENT:
                if (!perm || !capable(CAP_SYS_TTY_CONFIG))
                        return -EPERM;
                return vt_kdskbent(kb->kbdmode, kbe.kb_index, kbe.kb_table,
                                kbe.kb_value);
        }
        return 0;
}

static char *vt_kdskbsent(char *kbs, unsigned char cur)
{
        static DECLARE_BITMAP(is_kmalloc, MAX_NR_FUNC);
        char *cur_f = func_table[cur];

        if (cur_f && strlen(cur_f) >= strlen(kbs)) {
                strcpy(cur_f, kbs);
                return kbs;
        }

        func_table[cur] = kbs;

        return __test_and_set_bit(cur, is_kmalloc) ? cur_f : NULL;
}

int vt_do_kdgkb_ioctl(int cmd, struct kbsentry __user *user_kdgkb, int perm)
{
        unsigned char kb_func;

        if (get_user(kb_func, &user_kdgkb->kb_func))
                return -EFAULT;

        kb_func = array_index_nospec(kb_func, MAX_NR_FUNC);

        switch (cmd) {
        case KDGKBSENT: {
                /* size should have been a struct member */
                ssize_t len = sizeof(user_kdgkb->kb_string);

                char __free(kfree) *kbs = kmalloc(len, GFP_KERNEL);
                if (!kbs)
                        return -ENOMEM;

                scoped_guard(spinlock_irqsave, &func_buf_lock)
                        len = strscpy(kbs, func_table[kb_func] ? : "", len);

                if (len < 0)
                        return -ENOSPC;

                if (copy_to_user(user_kdgkb->kb_string, kbs, len + 1))
                        return -EFAULT;

                return 0;
        }
        case KDSKBSENT:
                if (!perm || !capable(CAP_SYS_TTY_CONFIG))
                        return -EPERM;

                char __free(kfree) *kbs = strndup_user(user_kdgkb->kb_string,
                                                       sizeof(user_kdgkb->kb_string));
                if (IS_ERR(kbs))
                        return PTR_ERR(kbs);

                guard(spinlock_irqsave)(&func_buf_lock);
                kbs = vt_kdskbsent(kbs, kb_func);

                return 0;
        }

        return 0;
}

int vt_do_kdskled(unsigned int console, int cmd, unsigned long arg, int perm)
{
        struct kbd_struct *kb = &kbd_table[console];
        unsigned char ucval;

        switch(cmd) {
        /* the ioctls below read/set the flags usually shown in the leds */
        /* don't use them - they will go away without warning */
        case KDGKBLED:
                scoped_guard(spinlock_irqsave, &kbd_event_lock)
                        ucval = kb->ledflagstate | (kb->default_ledflagstate << 4);
                return put_user(ucval, (char __user *)arg);

        case KDSKBLED:
                if (!perm)
                        return -EPERM;
                if (arg & ~0x77)
                        return -EINVAL;
                scoped_guard(spinlock_irqsave, &led_lock) {
                        kb->ledflagstate = (arg & 7);
                        kb->default_ledflagstate = ((arg >> 4) & 7);
                        set_leds();
                }
                return 0;

        /* the ioctls below only set the lights, not the functions */
        /* for those, see KDGKBLED and KDSKBLED above */
        case KDGETLED:
                ucval = getledstate();
                return put_user(ucval, (char __user *)arg);

        case KDSETLED:
                if (!perm)
                        return -EPERM;
                setledstate(kb, arg);
                return 0;
        }
        return -ENOIOCTLCMD;
}

int vt_do_kdgkbmode(unsigned int console)
{
        struct kbd_struct *kb = &kbd_table[console];
        /* This is a spot read so needs no locking */
        switch (kb->kbdmode) {
        case VC_RAW:
                return K_RAW;
        case VC_MEDIUMRAW:
                return K_MEDIUMRAW;
        case VC_UNICODE:
                return K_UNICODE;
        case VC_OFF:
                return K_OFF;
        default:
                return K_XLATE;
        }
}

/**
 *      vt_do_kdgkbmeta         -       report meta status
 *      @console: console to report
 *
 *      Report the meta flag status of this console
 */
int vt_do_kdgkbmeta(unsigned int console)
{
        struct kbd_struct *kb = &kbd_table[console];
        /* Again a spot read so no locking */
        return vc_kbd_mode(kb, VC_META) ? K_ESCPREFIX : K_METABIT;
}

/**
 *      vt_reset_unicode        -       reset the unicode status
 *      @console: console being reset
 *
 *      Restore the unicode console state to its default
 */
void vt_reset_unicode(unsigned int console)
{
        guard(spinlock_irqsave)(&kbd_event_lock);
        kbd_table[console].kbdmode = default_utf8 ? VC_UNICODE : VC_XLATE;
}

/**
 *      vt_get_shift_state      -       shift bit state
 *
 *      Report the shift bits from the keyboard state. We have to export
 *      this to support some oddities in the vt layer.
 */
int vt_get_shift_state(void)
{
        /* Don't lock as this is a transient report */
        return shift_state;
}

/**
 *      vt_reset_keyboard       -       reset keyboard state
 *      @console: console to reset
 *
 *      Reset the keyboard bits for a console as part of a general console
 *      reset event
 */
void vt_reset_keyboard(unsigned int console)
{
        struct kbd_struct *kb = &kbd_table[console];

        guard(spinlock_irqsave)(&kbd_event_lock);
        set_vc_kbd_mode(kb, VC_REPEAT);
        clr_vc_kbd_mode(kb, VC_CKMODE);
        clr_vc_kbd_mode(kb, VC_APPLIC);
        clr_vc_kbd_mode(kb, VC_CRLF);
        kb->lockstate = 0;
        kb->slockstate = 0;
        guard(spinlock)(&led_lock);
        kb->ledmode = LED_SHOW_FLAGS;
        kb->ledflagstate = kb->default_ledflagstate;
        /* do not do set_leds here because this causes an endless tasklet loop
           when the keyboard hasn't been initialized yet */
}

/**
 *      vt_get_kbd_mode_bit     -       read keyboard status bits
 *      @console: console to read from
 *      @bit: mode bit to read
 *
 *      Report back a vt mode bit. We do this without locking so the
 *      caller must be sure that there are no synchronization needs
 */

int vt_get_kbd_mode_bit(unsigned int console, int bit)
{
        struct kbd_struct *kb = &kbd_table[console];
        return vc_kbd_mode(kb, bit);
}

/**
 *      vt_set_kbd_mode_bit     -       read keyboard status bits
 *      @console: console to read from
 *      @bit: mode bit to read
 *
 *      Set a vt mode bit. We do this without locking so the
 *      caller must be sure that there are no synchronization needs
 */

void vt_set_kbd_mode_bit(unsigned int console, int bit)
{
        struct kbd_struct *kb = &kbd_table[console];

        guard(spinlock_irqsave)(&kbd_event_lock);
        set_vc_kbd_mode(kb, bit);
}

/**
 *      vt_clr_kbd_mode_bit     -       read keyboard status bits
 *      @console: console to read from
 *      @bit: mode bit to read
 *
 *      Report back a vt mode bit. We do this without locking so the
 *      caller must be sure that there are no synchronization needs
 */

void vt_clr_kbd_mode_bit(unsigned int console, int bit)
{
        struct kbd_struct *kb = &kbd_table[console];

        guard(spinlock_irqsave)(&kbd_event_lock);
        clr_vc_kbd_mode(kb, bit);
}