1 files changed, 549 insertions, 31 deletions

diff --git a/drivers/char/vt.c b/drivers/char/vt.c
index 6c94879e0b99..714d95ff2f1e 100644
--- a/drivers/char/vt.c
+++ b/drivers/char/vt.c
@@ -98,7 +98,22 @@
 #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
@@ -2557,7 +2572,7 @@ 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 +2584,22 @@ 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) {
@@ -2656,38 +2687,53 @@ 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 +2747,17 @@ 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 +2766,506 @@ 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;
+
+        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 < MAX_NR_CONSOLES; 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