1 files changed, 620 insertions, 68 deletions

diff --git a/drivers/char/vt.c b/drivers/char/vt.c
index 6c94879e0b99..fb75da940b59 100644
--- a/drivers/char/vt.c
+++ b/drivers/char/vt.c
@@ -63,6 +63,13 @@
  *
  * Removed console_lock, enabled interrupts across all console operations
  * 13 March 2001, Andrew Morton
+ *
+ * Fixed UTF-8 mode so alternate charset modes always work according
+ * to control sequences interpreted in do_con_trol function
+ * preserving backward VT100 semigraphics compatibility,
+ * malformed UTF sequences represented as sequences of replacement glyphs,
+ * original codes or '?' as a last resort if replacement glyph is undefined
+ * by Adam Tla/lka <atlka@pg.gda.pl>, Aug 2006
  */
 
 #include <linux/module.h>
@@ -79,7 +86,6 @@
 #include <linux/mm.h>
 #include <linux/console.h>
 #include <linux/init.h>
-#include <linux/devfs_fs_kernel.h>
 #include <linux/vt_kern.h>
 #include <linux/selection.h>
 #include <linux/tiocl.h>
@@ -87,7 +93,6 @@
 #include <linux/consolemap.h>
 #include <linux/timer.h>
 #include <linux/interrupt.h>
-#include <linux/config.h>
 #include <linux/workqueue.h>
 #include <linux/bootmem.h>
 #include <linux/pm.h>
@@ -98,7 +103,22 @@
 #include <asm/system.h>
 #include <asm/uaccess.h>
 
+#define MAX_NR_CON_DRIVER 16
+
+#define CON_DRIVER_FLAG_MODULE 1
+#define CON_DRIVER_FLAG_INIT 2
+
+struct con_driver {
+        const struct consw *con;
+        const char *desc;
+        struct class_device *class_dev;
+        int node;
+        int first;
+        int last;
+        int flag;
+};
 
+static struct con_driver registered_con_driver[MAX_NR_CON_DRIVER];
 const struct consw *conswitchp;
 
 /* A bitmap for codes <32. A bit of 1 indicates that the code
@@ -115,8 +135,8 @@ const struct consw *conswitchp;
 #define DEFAULT_BELL_PITCH      750
 #define DEFAULT_BELL_DURATION   (HZ/8)
 
-extern void vcs_make_devfs(struct tty_struct *tty);
-extern void vcs_remove_devfs(struct tty_struct *tty);
+extern void vcs_make_sysfs(struct tty_struct *tty);
+extern void vcs_remove_sysfs(struct tty_struct *tty);
 
 extern void console_map_init(void);
 #ifdef CONFIG_PROM_CONSOLE
@@ -717,7 +737,8 @@ int vc_allocate(unsigned int currcons)	/* return 0 on success */
             visual_init(vc, currcons, 1);
             if (!*vc->vc_uni_pagedir_loc)
                 con_set_default_unimap(vc);
-            vc->vc_screenbuf = kmalloc(vc->vc_screenbuf_size, GFP_KERNEL);
+            if (!vc->vc_kmalloced)
+                vc->vc_screenbuf = kmalloc(vc->vc_screenbuf_size, GFP_KERNEL);
             if (!vc->vc_screenbuf) {
                 kfree(vc);
                 vc_cons[currcons].d = NULL;
@@ -865,14 +886,24 @@ int vc_resize(struct vc_data *vc, unsigned int cols, unsigned int lines)
         return err;
 }
 
+int vc_lock_resize(struct vc_data *vc, unsigned int cols, unsigned int lines)
+{
+        int rc;
+
+        acquire_console_sem();
+        rc = vc_resize(vc, cols, lines);
+        release_console_sem();
+        return rc;
+}
 
-void vc_disallocate(unsigned int currcons)
+void vc_deallocate(unsigned int currcons)
 {
         WARN_CONSOLE_UNLOCKED();
 
         if (vc_cons_allocated(currcons)) {
                 struct vc_data *vc = vc_cons[currcons].d;
                 vc->vc_sw->con_deinit(vc);
+                module_put(vc->vc_sw->owner);
                 if (vc->vc_kmalloced)
                         kfree(vc->vc_screenbuf);
                 if (currcons >= MIN_NR_CONSOLES)
@@ -1991,17 +2022,23 @@ static int do_con_write(struct tty_struct *tty, const unsigned char *buf, int co
                 /* Do no translation at all in control states */
                 if (vc->vc_state != ESnormal) {
                         tc = c;
-                } else if (vc->vc_utf) {
+                } else if (vc->vc_utf && !vc->vc_disp_ctrl) {
                     /* Combine UTF-8 into Unicode */
-                    /* Incomplete characters silently ignored */
+                    /* Malformed sequences as sequences of replacement glyphs */
+rescan_last_byte:
                     if(c > 0x7f) {
-                        if (vc->vc_utf_count > 0 && (c & 0xc0) == 0x80) {
-                                vc->vc_utf_char = (vc->vc_utf_char << 6) | (c & 0x3f);
-                                vc->vc_utf_count--;
-                                if (vc->vc_utf_count == 0)
-                                    tc = c = vc->vc_utf_char;
-                                else continue;
+                        if (vc->vc_utf_count) {
+                               if ((c & 0xc0) == 0x80) {
+                                       vc->vc_utf_char = (vc->vc_utf_char << 6) | (c & 0x3f);
+                                       if (--vc->vc_utf_count) {
+                                               vc->vc_npar++;
+                                               continue;
+                                       }
+                                       tc = c = vc->vc_utf_char;
+                               } else
+                                       goto replacement_glyph;
                         } else {
+                                vc->vc_npar = 0;
                                 if ((c & 0xe0) == 0xc0) {
                                     vc->vc_utf_count = 1;
                                     vc->vc_utf_char = (c & 0x1f);
@@ -2018,14 +2055,15 @@ static int do_con_write(struct tty_struct *tty, const unsigned char *buf, int co
                                     vc->vc_utf_count = 5;
                                     vc->vc_utf_char = (c & 0x01);
                                 } else
-                                    vc->vc_utf_count = 0;
+                                    goto replacement_glyph;
                                 continue;
                               }
                     } else {
+                      if (vc->vc_utf_count)
+                              goto replacement_glyph;
                       tc = c;
-                      vc->vc_utf_count = 0;
                     }
-                } else {        /* no utf */
+                } else {        /* no utf or alternate charset mode */
                   tc = vc->vc_translate[vc->vc_toggle_meta ? (c | 0x80) : c];
                 }
 
@@ -2040,31 +2078,33 @@ static int do_con_write(struct tty_struct *tty, const unsigned char *buf, int co
                  * direct-to-font zone in UTF-8 mode.
                  */
                 ok = tc && (c >= 32 ||
-                            (!vc->vc_utf && !(((vc->vc_disp_ctrl ? CTRL_ALWAYS
-                                                : CTRL_ACTION) >> c) & 1)))
+                            !(vc->vc_disp_ctrl ? (CTRL_ALWAYS >> c) & 1 :
+                                  vc->vc_utf || ((CTRL_ACTION >> c) & 1)))
                         && (c != 127 || vc->vc_disp_ctrl)
                         && (c != 128+27);
 
                 if (vc->vc_state == ESnormal && ok) {
                         /* Now try to find out how to display it */
                         tc = conv_uni_to_pc(vc, tc);
-                        if ( tc == -4 ) {
+                        if (tc & ~charmask) {
+                                if ( tc == -4 ) {
                                 /* If we got -4 (not found) then see if we have
                                    defined a replacement character (U+FFFD) */
-                                tc = conv_uni_to_pc(vc, 0xfffd);
-
-                                /* One reason for the -4 can be that we just
-                                   did a clear_unimap();
-                                   try at least to show something. */
-                                if (tc == -4)
-                                     tc = c;
-                        } else if ( tc == -3 ) {
-                                /* Bad hash table -- hope for the best */
-                                tc = c;
-                        }
-                        if (tc & ~charmask)
-                                continue; /* Conversion failed */
+replacement_glyph:
+                                        tc = conv_uni_to_pc(vc, 0xfffd);
+                                        if (!(tc & ~charmask))
+                                                goto display_glyph;
+                                } else if ( tc != -3 )
+                                        continue; /* nothing to display */
+                                /* no hash table or no replacement --
+                                 * hope for the best */
+                                if ( c & ~charmask )
+                                        tc = '?';
+                                else
+                                        tc = c;
+                        }
 
+display_glyph:
                         if (vc->vc_need_wrap || vc->vc_decim)
                                 FLUSH
                         if (vc->vc_need_wrap) {
@@ -2088,6 +2128,15 @@ static int do_con_write(struct tty_struct *tty, const unsigned char *buf, int co
                                 vc->vc_x++;
                                 draw_to = (vc->vc_pos += 2);
                         }
+                        if (vc->vc_utf_count) {
+                                if (vc->vc_npar) {
+                                        vc->vc_npar--;
+                                        goto display_glyph;
+                                }
+                                vc->vc_utf_count = 0;
+                                c = orig;
+                                goto rescan_last_byte;
+                        }
                         continue;
                 }
                 FLUSH
@@ -2484,7 +2533,7 @@ static int con_open(struct tty_struct *tty, struct file *filp)
                                 tty->winsize.ws_col = vc_cons[currcons].d->vc_cols;
                         }
                         release_console_sem();
-                        vcs_make_devfs(tty);
+                        vcs_make_sysfs(tty);
                         return ret;
                 }
         }
@@ -2497,7 +2546,7 @@ static int con_open(struct tty_struct *tty, struct file *filp)
  * and taking a ref against the tty while we're in the process of forgetting
  * about it and cleaning things up.
  *
- * This is because vcs_remove_devfs() can sleep and will drop the BKL.
+ * This is because vcs_remove_sysfs() can sleep and will drop the BKL.
  */
 static void con_close(struct tty_struct *tty, struct file *filp)
 {
@@ -2510,7 +2559,7 @@ static void con_close(struct tty_struct *tty, struct file *filp)
                         vc->vc_tty = NULL;
                 tty->driver_data = NULL;
                 release_console_sem();
-                vcs_remove_devfs(tty);
+                vcs_remove_sysfs(tty);
                 mutex_unlock(&tty_mutex);
                 /*
                  * tty_mutex is released, but we still hold BKL, so there is
@@ -2557,7 +2606,7 @@ static int __init con_init(void)
 {
         const char *display_desc = NULL;
         struct vc_data *vc;
-        unsigned int currcons = 0;
+        unsigned int currcons = 0, i;
 
         acquire_console_sem();
 
@@ -2569,6 +2618,22 @@ static int __init con_init(void)
                 return 0;
         }
 
+        for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
+                struct con_driver *con_driver = &registered_con_driver[i];
+
+                if (con_driver->con == NULL) {
+                        con_driver->con = conswitchp;
+                        con_driver->desc = display_desc;
+                        con_driver->flag = CON_DRIVER_FLAG_INIT;
+                        con_driver->first = 0;
+                        con_driver->last = MAX_NR_CONSOLES - 1;
+                        break;
+                }
+        }
+
+        for (i = 0; i < MAX_NR_CONSOLES; i++)
+                con_driver_map[i] = conswitchp;
+
         init_timer(&console_timer);
         console_timer.function = blank_screen_t;
         if (blankinterval) {
@@ -2632,7 +2697,6 @@ int __init vty_init(void)
         if (!console_driver)
                 panic("Couldn't allocate console driver\n");
         console_driver->owner = THIS_MODULE;
-        console_driver->devfs_name = "vc/";
         console_driver->name = "tty";
         console_driver->name_base = 1;
         console_driver->major = TTY_MAJOR;
@@ -2656,38 +2720,53 @@ int __init vty_init(void)
 }
 
 #ifndef VT_SINGLE_DRIVER
+#include <linux/device.h>
 
-/*
- *      If we support more console drivers, this function is used
- *      when a driver wants to take over some existing consoles
- *      and become default driver for newly opened ones.
- */
+static struct class *vtconsole_class;
 
-int take_over_console(const struct consw *csw, int first, int last, int deflt)
+static int bind_con_driver(const struct consw *csw, int first, int last,
+                           int deflt)
 {
-        int i, j = -1;
-        const char *desc;
-        struct module *owner;
+        struct module *owner = csw->owner;
+        const char *desc = NULL;
+        struct con_driver *con_driver;
+        int i, j = -1, k = -1, retval = -ENODEV;
 
-        owner = csw->owner;
         if (!try_module_get(owner))
                 return -ENODEV;
 
         acquire_console_sem();
 
-        desc = csw->con_startup();
-        if (!desc) {
-                release_console_sem();
-                module_put(owner);
-                return -ENODEV;
+        /* check if driver is registered */
+        for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
+                con_driver = &registered_con_driver[i];
+
+                if (con_driver->con == csw) {
+                        desc = con_driver->desc;
+                        retval = 0;
+                        break;
+                }
+        }
+
+        if (retval)
+                goto err;
+
+        if (!(con_driver->flag & CON_DRIVER_FLAG_INIT)) {
+                csw->con_startup();
+                con_driver->flag |= CON_DRIVER_FLAG_INIT;
         }
+
         if (deflt) {
                 if (conswitchp)
                         module_put(conswitchp->owner);
+
                 __module_get(owner);
                 conswitchp = csw;
         }
 
+        first = max(first, con_driver->first);
+        last = min(last, con_driver->last);
+
         for (i = first; i <= last; i++) {
                 int old_was_color;
                 struct vc_data *vc = vc_cons[i].d;
@@ -2701,15 +2780,17 @@ int take_over_console(const struct consw *csw, int first, int last, int deflt)
                         continue;
 
                 j = i;
-                if (CON_IS_VISIBLE(vc))
+
+                if (CON_IS_VISIBLE(vc)) {
+                        k = i;
                         save_screen(vc);
+                }
+
                 old_was_color = vc->vc_can_do_color;
                 vc->vc_sw->con_deinit(vc);
                 vc->vc_origin = (unsigned long)vc->vc_screenbuf;
-                vc->vc_visible_origin = vc->vc_origin;
-                vc->vc_scr_end = vc->vc_origin + vc->vc_screenbuf_size;
-                vc->vc_pos = vc->vc_origin + vc->vc_size_row * vc->vc_y + 2 * vc->vc_x;
                 visual_init(vc, i, 0);
+                set_origin(vc);
                 update_attr(vc);
 
                 /* If the console changed between mono <-> color, then
@@ -2718,36 +2799,506 @@ int take_over_console(const struct consw *csw, int first, int last, int deflt)
                  */
                 if (old_was_color != vc->vc_can_do_color)
                         clear_buffer_attributes(vc);
-
-                if (CON_IS_VISIBLE(vc))
-                        update_screen(vc);
         }
+
         printk("Console: switching ");
         if (!deflt)
                 printk("consoles %d-%d ", first+1, last+1);
-        if (j >= 0)
+        if (j >= 0) {
+                struct vc_data *vc = vc_cons[j].d;
+
                 printk("to %s %s %dx%d\n",
-                       vc_cons[j].d->vc_can_do_color ? "colour" : "mono",
-                       desc, vc_cons[j].d->vc_cols, vc_cons[j].d->vc_rows);
-        else
+                       vc->vc_can_do_color ? "colour" : "mono",
+                       desc, vc->vc_cols, vc->vc_rows);
+
+                if (k >= 0) {
+                        vc = vc_cons[k].d;
+                        update_screen(vc);
+                }
+        } else
                 printk("to %s\n", desc);
 
+        retval = 0;
+err:
         release_console_sem();
+        module_put(owner);
+        return retval;
+};
+
+#ifdef CONFIG_VT_HW_CONSOLE_BINDING
+static int con_is_graphics(const struct consw *csw, int first, int last)
+{
+        int i, retval = 0;
+
+        for (i = first; i <= last; i++) {
+                struct vc_data *vc = vc_cons[i].d;
+
+                if (vc && vc->vc_mode == KD_GRAPHICS) {
+                        retval = 1;
+                        break;
+                }
+        }
 
+        return retval;
+}
+
+static int unbind_con_driver(const struct consw *csw, int first, int last,
+                             int deflt)
+{
+        struct module *owner = csw->owner;
+        const struct consw *defcsw = NULL;
+        struct con_driver *con_driver = NULL, *con_back = NULL;
+        int i, retval = -ENODEV;
+
+        if (!try_module_get(owner))
+                return -ENODEV;
+
+        acquire_console_sem();
+
+        /* check if driver is registered and if it is unbindable */
+        for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
+                con_driver = &registered_con_driver[i];
+
+                if (con_driver->con == csw &&
+                    con_driver->flag & CON_DRIVER_FLAG_MODULE) {
+                        retval = 0;
+                        break;
+                }
+        }
+
+        if (retval) {
+                release_console_sem();
+                goto err;
+        }
+
+        retval = -ENODEV;
+
+        /* check if backup driver exists */
+        for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
+                con_back = &registered_con_driver[i];
+
+                if (con_back->con &&
+                    !(con_back->flag & CON_DRIVER_FLAG_MODULE)) {
+                        defcsw = con_back->con;
+                        retval = 0;
+                        break;
+                }
+        }
+
+        if (retval) {
+                release_console_sem();
+                goto err;
+        }
+
+        if (!con_is_bound(csw)) {
+                release_console_sem();
+                goto err;
+        }
+
+        first = max(first, con_driver->first);
+        last = min(last, con_driver->last);
+
+        for (i = first; i <= last; i++) {
+                if (con_driver_map[i] == csw) {
+                        module_put(csw->owner);
+                        con_driver_map[i] = NULL;
+                }
+        }
+
+        if (!con_is_bound(defcsw)) {
+                const struct consw *defconsw = conswitchp;
+
+                defcsw->con_startup();
+                con_back->flag |= CON_DRIVER_FLAG_INIT;
+                /*
+                 * vgacon may change the default driver to point
+                 * to dummycon, we restore it here...
+                 */
+                conswitchp = defconsw;
+        }
+
+        if (!con_is_bound(csw))
+                con_driver->flag &= ~CON_DRIVER_FLAG_INIT;
+
+        release_console_sem();
+        /* ignore return value, binding should not fail */
+        bind_con_driver(defcsw, first, last, deflt);
+err:
         module_put(owner);
+        return retval;
+
+}
+
+static int vt_bind(struct con_driver *con)
+{
+        const struct consw *defcsw = NULL, *csw = NULL;
+        int i, more = 1, first = -1, last = -1, deflt = 0;
+
+        if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE) ||
+            con_is_graphics(con->con, con->first, con->last))
+                goto err;
+
+        csw = con->con;
+
+        for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
+                struct con_driver *con = &registered_con_driver[i];
+
+                if (con->con && !(con->flag & CON_DRIVER_FLAG_MODULE)) {
+                        defcsw = con->con;
+                        break;
+                }
+        }
+
+        if (!defcsw)
+                goto err;
+
+        while (more) {
+                more = 0;
+
+                for (i = con->first; i <= con->last; i++) {
+                        if (con_driver_map[i] == defcsw) {
+                                if (first == -1)
+                                        first = i;
+                                last = i;
+                                more = 1;
+                        } else if (first != -1)
+                                break;
+                }
+
+                if (first == 0 && last == MAX_NR_CONSOLES -1)
+                        deflt = 1;
+
+                if (first != -1)
+                        bind_con_driver(csw, first, last, deflt);
+
+                first = -1;
+                last = -1;
+                deflt = 0;
+        }
+
+err:
         return 0;
 }
 
-void give_up_console(const struct consw *csw)
+static int vt_unbind(struct con_driver *con)
+{
+        const struct consw *csw = NULL;
+        int i, more = 1, first = -1, last = -1, deflt = 0;
+
+        if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE) ||
+            con_is_graphics(con->con, con->first, con->last))
+                goto err;
+
+        csw = con->con;
+
+        while (more) {
+                more = 0;
+
+                for (i = con->first; i <= con->last; i++) {
+                        if (con_driver_map[i] == csw) {
+                                if (first == -1)
+                                        first = i;
+                                last = i;
+                                more = 1;
+                        } else if (first != -1)
+                                break;
+                }
+
+                if (first == 0 && last == MAX_NR_CONSOLES -1)
+                        deflt = 1;
+
+                if (first != -1)
+                        unbind_con_driver(csw, first, last, deflt);
+
+                first = -1;
+                last = -1;
+                deflt = 0;
+        }
+
+err:
+        return 0;
+}
+#else
+static inline int vt_bind(struct con_driver *con)
+{
+        return 0;
+}
+static inline int vt_unbind(struct con_driver *con)
+{
+        return 0;
+}
+#endif /* CONFIG_VT_HW_CONSOLE_BINDING */
+
+static ssize_t store_bind(struct class_device *class_device,
+                          const char *buf, size_t count)
+{
+        struct con_driver *con = class_get_devdata(class_device);
+        int bind = simple_strtoul(buf, NULL, 0);
+
+        if (bind)
+                vt_bind(con);
+        else
+                vt_unbind(con);
+
+        return count;
+}
+
+static ssize_t show_bind(struct class_device *class_device, char *buf)
+{
+        struct con_driver *con = class_get_devdata(class_device);
+        int bind = con_is_bound(con->con);
+
+        return snprintf(buf, PAGE_SIZE, "%i\n", bind);
+}
+
+static ssize_t show_name(struct class_device *class_device, char *buf)
+{
+        struct con_driver *con = class_get_devdata(class_device);
+
+        return snprintf(buf, PAGE_SIZE, "%s %s\n",
+                        (con->flag & CON_DRIVER_FLAG_MODULE) ? "(M)" : "(S)",
+                         con->desc);
+
+}
+
+static struct class_device_attribute class_device_attrs[] = {
+        __ATTR(bind, S_IRUGO|S_IWUSR, show_bind, store_bind),
+        __ATTR(name, S_IRUGO, show_name, NULL),
+};
+
+static int vtconsole_init_class_device(struct con_driver *con)
 {
         int i;
 
-        for(i = 0; i < MAX_NR_CONSOLES; i++)
+        class_set_devdata(con->class_dev, con);
+        for (i = 0; i < ARRAY_SIZE(class_device_attrs); i++)
+                class_device_create_file(con->class_dev,
+                                         &class_device_attrs[i]);
+
+        return 0;
+}
+
+static void vtconsole_deinit_class_device(struct con_driver *con)
+{
+        int i;
+
+        for (i = 0; i < ARRAY_SIZE(class_device_attrs); i++)
+                class_device_remove_file(con->class_dev,
+                                         &class_device_attrs[i]);
+}
+
+/**
+ * con_is_bound - checks if driver is bound to the console
+ * @csw: console driver
+ *
+ * RETURNS: zero if unbound, nonzero if bound
+ *
+ * Drivers can call this and if zero, they should release
+ * all resources allocated on con_startup()
+ */
+int con_is_bound(const struct consw *csw)
+{
+        int i, bound = 0;
+
+        for (i = 0; i < MAX_NR_CONSOLES; i++) {
                 if (con_driver_map[i] == csw) {
-                        module_put(csw->owner);
-                        con_driver_map[i] = NULL;
+                        bound = 1;
+                        break;
+                }
+        }
+
+        return bound;
+}
+EXPORT_SYMBOL(con_is_bound);
+
+/**
+ * register_con_driver - register console driver to console layer
+ * @csw: console driver
+ * @first: the first console to take over, minimum value is 0
+ * @last: the last console to take over, maximum value is MAX_NR_CONSOLES -1
+ *
+ * DESCRIPTION: This function registers a console driver which can later
+ * bind to a range of consoles specified by @first and @last. It will
+ * also initialize the console driver by calling con_startup().
+ */
+int register_con_driver(const struct consw *csw, int first, int last)
+{
+        struct module *owner = csw->owner;
+        struct con_driver *con_driver;
+        const char *desc;
+        int i, retval = 0;
+
+        if (!try_module_get(owner))
+                return -ENODEV;
+
+        acquire_console_sem();
+
+        for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
+                con_driver = &registered_con_driver[i];
+
+                /* already registered */
+                if (con_driver->con == csw)
+                        retval = -EINVAL;
+        }
+
+        if (retval)
+                goto err;
+
+        desc = csw->con_startup();
+
+        if (!desc)
+                goto err;
+
+        retval = -EINVAL;
+
+        for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
+                con_driver = &registered_con_driver[i];
+
+                if (con_driver->con == NULL) {
+                        con_driver->con = csw;
+                        con_driver->desc = desc;
+                        con_driver->node = i;
+                        con_driver->flag = CON_DRIVER_FLAG_MODULE |
+                                           CON_DRIVER_FLAG_INIT;
+                        con_driver->first = first;
+                        con_driver->last = last;
+                        retval = 0;
+                        break;
                 }
+        }
+
+        if (retval)
+                goto err;
+
+        con_driver->class_dev = class_device_create(vtconsole_class, NULL,
+                                                    MKDEV(0, con_driver->node),
+                                                    NULL, "vtcon%i",
+                                                    con_driver->node);
+
+        if (IS_ERR(con_driver->class_dev)) {
+                printk(KERN_WARNING "Unable to create class_device for %s; "
+                       "errno = %ld\n", con_driver->desc,
+                       PTR_ERR(con_driver->class_dev));
+                con_driver->class_dev = NULL;
+        } else {
+                vtconsole_init_class_device(con_driver);
+        }
+err:
+        release_console_sem();
+        module_put(owner);
+        return retval;
+}
+EXPORT_SYMBOL(register_con_driver);
+
+/**
+ * unregister_con_driver - unregister console driver from console layer
+ * @csw: console driver
+ *
+ * DESCRIPTION: All drivers that registers to the console layer must
+ * call this function upon exit, or if the console driver is in a state
+ * where it won't be able to handle console services, such as the
+ * framebuffer console without loaded framebuffer drivers.
+ *
+ * The driver must unbind first prior to unregistration.
+ */
+int unregister_con_driver(const struct consw *csw)
+{
+        int i, retval = -ENODEV;
+
+        acquire_console_sem();
+
+        /* cannot unregister a bound driver */
+        if (con_is_bound(csw))
+                goto err;
+
+        for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
+                struct con_driver *con_driver = &registered_con_driver[i];
+
+                if (con_driver->con == csw &&
+                    con_driver->flag & CON_DRIVER_FLAG_MODULE) {
+                        vtconsole_deinit_class_device(con_driver);
+                        class_device_destroy(vtconsole_class,
+                                             MKDEV(0, con_driver->node));
+                        con_driver->con = NULL;
+                        con_driver->desc = NULL;
+                        con_driver->class_dev = NULL;
+                        con_driver->node = 0;
+                        con_driver->flag = 0;
+                        con_driver->first = 0;
+                        con_driver->last = 0;
+                        retval = 0;
+                        break;
+                }
+        }
+err:
+        release_console_sem();
+        return retval;
+}
+EXPORT_SYMBOL(unregister_con_driver);
+
+/*
+ *      If we support more console drivers, this function is used
+ *      when a driver wants to take over some existing consoles
+ *      and become default driver for newly opened ones.
+ *
+ *      take_over_console is basically a register followed by unbind
+ */
+int take_over_console(const struct consw *csw, int first, int last, int deflt)
+{
+        int err;
+
+        err = register_con_driver(csw, first, last);
+
+        if (!err)
+                bind_con_driver(csw, first, last, deflt);
+
+        return err;
+}
+
+/*
+ * give_up_console is a wrapper to unregister_con_driver. It will only
+ * work if driver is fully unbound.
+ */
+void give_up_console(const struct consw *csw)
+{
+        unregister_con_driver(csw);
+}
+
+static int __init vtconsole_class_init(void)
+{
+        int i;
+
+        vtconsole_class = class_create(THIS_MODULE, "vtconsole");
+        if (IS_ERR(vtconsole_class)) {
+                printk(KERN_WARNING "Unable to create vt console class; "
+                       "errno = %ld\n", PTR_ERR(vtconsole_class));
+                vtconsole_class = NULL;
+        }
+
+        /* Add system drivers to sysfs */
+        for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
+                struct con_driver *con = &registered_con_driver[i];
+
+                if (con->con && !con->class_dev) {
+                        con->class_dev =
+                                class_device_create(vtconsole_class, NULL,
+                                                    MKDEV(0, con->node), NULL,
+                                                    "vtcon%i", con->node);
+
+                        if (IS_ERR(con->class_dev)) {
+                                printk(KERN_WARNING "Unable to create "
+                                       "class_device for %s; errno = %ld\n",
+                                       con->desc, PTR_ERR(con->class_dev));
+                                con->class_dev = NULL;
+                        } else {
+                                vtconsole_init_class_device(con);
+                        }
+                }
+        }
+
+        return 0;
 }
+postcore_initcall(vtconsole_class_init);
 
 #endif
 
@@ -3249,6 +3800,7 @@ EXPORT_SYMBOL(default_blu);
 EXPORT_SYMBOL(update_region);
 EXPORT_SYMBOL(redraw_screen);
 EXPORT_SYMBOL(vc_resize);
+EXPORT_SYMBOL(vc_lock_resize);
 EXPORT_SYMBOL(fg_console);
 EXPORT_SYMBOL(console_blank_hook);
 EXPORT_SYMBOL(console_blanked);