Merge ../torvalds-2.6/
[pandora-kernel.git] / drivers / char / tty_io.c
index 26e5e19..e5953f3 100644 (file)
@@ -94,6 +94,7 @@
 #include <linux/idr.h>
 #include <linux/wait.h>
 #include <linux/bitops.h>
+#include <linux/delay.h>
 
 #include <asm/uaccess.h>
 #include <asm/system.h>
@@ -152,7 +153,6 @@ static int tty_release(struct inode *, struct file *);
 int tty_ioctl(struct inode * inode, struct file * file,
              unsigned int cmd, unsigned long arg);
 static int tty_fasync(int fd, struct file * filp, int on);
-extern void rs_360_init(void);
 static void release_mem(struct tty_struct *tty, int idx);
 
 
@@ -251,7 +251,7 @@ static void tty_set_termios_ldisc(struct tty_struct *tty, int num)
  
 static DEFINE_SPINLOCK(tty_ldisc_lock);
 static DECLARE_WAIT_QUEUE_HEAD(tty_ldisc_wait);
-static struct tty_ldisc tty_ldiscs[NR_LDISCS]; /* line disc dispatch table     */
+static struct tty_ldisc tty_ldiscs[NR_LDISCS]; /* line disc dispatch table */
 
 int tty_register_ldisc(int disc, struct tty_ldisc *new_ldisc)
 {
@@ -262,24 +262,35 @@ int tty_register_ldisc(int disc, struct tty_ldisc *new_ldisc)
                return -EINVAL;
        
        spin_lock_irqsave(&tty_ldisc_lock, flags);
-       if (new_ldisc) {
-               tty_ldiscs[disc] = *new_ldisc;
-               tty_ldiscs[disc].num = disc;
-               tty_ldiscs[disc].flags |= LDISC_FLAG_DEFINED;
-               tty_ldiscs[disc].refcount = 0;
-       } else {
-               if(tty_ldiscs[disc].refcount)
-                       ret = -EBUSY;
-               else
-                       tty_ldiscs[disc].flags &= ~LDISC_FLAG_DEFINED;
-       }
+       tty_ldiscs[disc] = *new_ldisc;
+       tty_ldiscs[disc].num = disc;
+       tty_ldiscs[disc].flags |= LDISC_FLAG_DEFINED;
+       tty_ldiscs[disc].refcount = 0;
        spin_unlock_irqrestore(&tty_ldisc_lock, flags);
        
        return ret;
 }
-
 EXPORT_SYMBOL(tty_register_ldisc);
 
+int tty_unregister_ldisc(int disc)
+{
+       unsigned long flags;
+       int ret = 0;
+
+       if (disc < N_TTY || disc >= NR_LDISCS)
+               return -EINVAL;
+
+       spin_lock_irqsave(&tty_ldisc_lock, flags);
+       if (tty_ldiscs[disc].refcount)
+               ret = -EBUSY;
+       else
+               tty_ldiscs[disc].flags &= ~LDISC_FLAG_DEFINED;
+       spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+
+       return ret;
+}
+EXPORT_SYMBOL(tty_unregister_ldisc);
+
 struct tty_ldisc *tty_ldisc_get(int disc)
 {
        unsigned long flags;
@@ -458,21 +469,19 @@ static void tty_ldisc_enable(struct tty_struct *tty)
  
 static int tty_set_ldisc(struct tty_struct *tty, int ldisc)
 {
-       int     retval = 0;
-       struct  tty_ldisc o_ldisc;
+       int retval = 0;
+       struct tty_ldisc o_ldisc;
        char buf[64];
        int work;
        unsigned long flags;
        struct tty_ldisc *ld;
+       struct tty_struct *o_tty;
 
        if ((ldisc < N_TTY) || (ldisc >= NR_LDISCS))
                return -EINVAL;
 
 restart:
 
-       if (tty->ldisc.num == ldisc)
-               return 0;       /* We are already in the desired discipline */
-       
        ld = tty_ldisc_get(ldisc);
        /* Eduardo Blanco <ejbs@cs.cs.com.uy> */
        /* Cyrus Durgin <cider@speakeasy.org> */
@@ -483,45 +492,74 @@ restart:
        if (ld == NULL)
                return -EINVAL;
 
-       o_ldisc = tty->ldisc;
-
        tty_wait_until_sent(tty, 0);
 
+       if (tty->ldisc.num == ldisc) {
+               tty_ldisc_put(ldisc);
+               return 0;
+       }
+
+       o_ldisc = tty->ldisc;
+       o_tty = tty->link;
+
        /*
         *      Make sure we don't change while someone holds a
         *      reference to the line discipline. The TTY_LDISC bit
         *      prevents anyone taking a reference once it is clear.
         *      We need the lock to avoid racing reference takers.
         */
-        
+
        spin_lock_irqsave(&tty_ldisc_lock, flags);
-       if(tty->ldisc.refcount)
-       {
-               /* Free the new ldisc we grabbed. Must drop the lock
-                  first. */
+       if (tty->ldisc.refcount || (o_tty && o_tty->ldisc.refcount)) {
+               if(tty->ldisc.refcount) {
+                       /* Free the new ldisc we grabbed. Must drop the lock
+                          first. */
+                       spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+                       tty_ldisc_put(ldisc);
+                       /*
+                        * There are several reasons we may be busy, including
+                        * random momentary I/O traffic. We must therefore
+                        * retry. We could distinguish between blocking ops
+                        * and retries if we made tty_ldisc_wait() smarter. That
+                        * is up for discussion.
+                        */
+                       if (wait_event_interruptible(tty_ldisc_wait, tty->ldisc.refcount == 0) < 0)
+                               return -ERESTARTSYS;
+                       goto restart;
+               }
+               if(o_tty && o_tty->ldisc.refcount) {
+                       spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+                       tty_ldisc_put(ldisc);
+                       if (wait_event_interruptible(tty_ldisc_wait, o_tty->ldisc.refcount == 0) < 0)
+                               return -ERESTARTSYS;
+                       goto restart;
+               }
+       }
+
+       /* if the TTY_LDISC bit is set, then we are racing against another ldisc change */
+
+       if (!test_bit(TTY_LDISC, &tty->flags)) {
                spin_unlock_irqrestore(&tty_ldisc_lock, flags);
                tty_ldisc_put(ldisc);
-               /*
-                * There are several reasons we may be busy, including
-                * random momentary I/O traffic. We must therefore
-                * retry. We could distinguish between blocking ops
-                * and retries if we made tty_ldisc_wait() smarter. That
-                * is up for discussion.
-                */
-               if(wait_event_interruptible(tty_ldisc_wait, tty->ldisc.refcount == 0) < 0)
-                       return -ERESTARTSYS;                    
+               ld = tty_ldisc_ref_wait(tty);
+               tty_ldisc_deref(ld);
                goto restart;
        }
-       clear_bit(TTY_LDISC, &tty->flags);      
+
+       clear_bit(TTY_LDISC, &tty->flags);
        clear_bit(TTY_DONT_FLIP, &tty->flags);
+       if (o_tty) {
+               clear_bit(TTY_LDISC, &o_tty->flags);
+               clear_bit(TTY_DONT_FLIP, &o_tty->flags);
+       }
        spin_unlock_irqrestore(&tty_ldisc_lock, flags);
-       
+
        /*
         *      From this point on we know nobody has an ldisc
         *      usage reference, nor can they obtain one until
         *      we say so later on.
         */
-        
+
        work = cancel_delayed_work(&tty->flip.work);
        /*
         * Wait for ->hangup_work and ->flip.work handlers to terminate
@@ -572,10 +610,12 @@ restart:
         */
         
        tty_ldisc_enable(tty);
+       if (o_tty)
+               tty_ldisc_enable(o_tty);
        
        /* Restart it in case no characters kick it off. Safe if
           already running */
-       if(work)
+       if (work)
                schedule_delayed_work(&tty->flip.work, 1);
        return retval;
 }
@@ -2169,12 +2209,11 @@ static int tiocsetd(struct tty_struct *tty, int __user *p)
        return tty_set_ldisc(tty, ldisc);
 }
 
-static int send_break(struct tty_struct *tty, int duration)
+static int send_break(struct tty_struct *tty, unsigned int duration)
 {
        tty->driver->break_ctl(tty, -1);
        if (!signal_pending(current)) {
-               set_current_state(TASK_INTERRUPTIBLE);
-               schedule_timeout(duration);
+               msleep_interruptible(duration);
        }
        tty->driver->break_ctl(tty, 0);
        if (signal_pending(current))
@@ -2355,10 +2394,10 @@ int tty_ioctl(struct inode * inode, struct file * file,
                         * all by anyone?
                         */
                        if (!arg)
-                               return send_break(tty, HZ/4);
+                               return send_break(tty, 250);
                        return 0;
                case TCSBRKP:   /* support for POSIX tcsendbreak() */   
-                       return send_break(tty, arg ? arg*(HZ/10) : HZ/4);
+                       return send_break(tty, arg ? arg*100 : 250);
 
                case TIOCMGET:
                        return tty_tiocmget(tty, file, p);
@@ -2415,6 +2454,7 @@ static void __do_SAK(void *arg)
        int             i;
        struct file     *filp;
        struct tty_ldisc *disc;
+       struct fdtable *fdt;
        
        if (!tty)
                return;
@@ -2440,8 +2480,9 @@ static void __do_SAK(void *arg)
                }
                task_lock(p);
                if (p->files) {
-                       spin_lock(&p->files->file_lock);
-                       for (i=0; i < p->files->max_fds; i++) {
+                       rcu_read_lock();
+                       fdt = files_fdtable(p->files);
+                       for (i=0; i < fdt->max_fds; i++) {
                                filp = fcheck_files(p->files, i);
                                if (!filp)
                                        continue;
@@ -2454,7 +2495,7 @@ static void __do_SAK(void *arg)
                                        break;
                                }
                        }
-                       spin_unlock(&p->files->file_lock);
+                       rcu_read_unlock();
                }
                task_unlock(p);
        } while_each_task_pid(session, PIDTYPE_SID, p);
@@ -2654,7 +2695,7 @@ static void tty_default_put_char(struct tty_struct *tty, unsigned char ch)
        tty->driver->write(tty, &ch, 1);
 }
 
-static struct class_simple *tty_class;
+static struct class *tty_class;
 
 /**
  * tty_register_device - register a tty device
@@ -2687,7 +2728,7 @@ void tty_register_device(struct tty_driver *driver, unsigned index,
                pty_line_name(driver, index, name);
        else
                tty_line_name(driver, index, name);
-       class_simple_device_add(tty_class, dev, device, name);
+       class_device_create(tty_class, dev, device, name);
 }
 
 /**
@@ -2701,7 +2742,7 @@ void tty_register_device(struct tty_driver *driver, unsigned index,
 void tty_unregister_device(struct tty_driver *driver, unsigned index)
 {
        devfs_remove("%s%d", driver->devfs_name, index + driver->name_base);
-       class_simple_device_remove(MKDEV(driver->major, driver->minor_start) + index);
+       class_device_destroy(tty_class, MKDEV(driver->major, driver->minor_start) + index);
 }
 
 EXPORT_SYMBOL(tty_register_device);
@@ -2899,11 +2940,6 @@ void __init console_init(void)
         */
 #ifdef CONFIG_EARLY_PRINTK
        disable_early_printk();
-#endif
-#ifdef CONFIG_SERIAL_68360
-       /* This is not a console initcall. I know not what it's doing here.
-          So I haven't moved it. dwmw2 */
-        rs_360_init();
 #endif
        call = __con_initcall_start;
        while (call < __con_initcall_end) {
@@ -2918,7 +2954,7 @@ extern int vty_init(void);
 
 static int __init tty_class_init(void)
 {
-       tty_class = class_simple_create(THIS_MODULE, "tty");
+       tty_class = class_create(THIS_MODULE, "tty");
        if (IS_ERR(tty_class))
                return PTR_ERR(tty_class);
        return 0;
@@ -2947,14 +2983,14 @@ static int __init tty_init(void)
            register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0)
                panic("Couldn't register /dev/tty driver\n");
        devfs_mk_cdev(MKDEV(TTYAUX_MAJOR, 0), S_IFCHR|S_IRUGO|S_IWUGO, "tty");
-       class_simple_device_add(tty_class, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty");
+       class_device_create(tty_class, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty");
 
        cdev_init(&console_cdev, &console_fops);
        if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) ||
            register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0)
                panic("Couldn't register /dev/console driver\n");
        devfs_mk_cdev(MKDEV(TTYAUX_MAJOR, 1), S_IFCHR|S_IRUSR|S_IWUSR, "console");
-       class_simple_device_add(tty_class, MKDEV(TTYAUX_MAJOR, 1), NULL, "console");
+       class_device_create(tty_class, MKDEV(TTYAUX_MAJOR, 1), NULL, "console");
 
 #ifdef CONFIG_UNIX98_PTYS
        cdev_init(&ptmx_cdev, &ptmx_fops);
@@ -2962,7 +2998,7 @@ static int __init tty_init(void)
            register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0)
                panic("Couldn't register /dev/ptmx driver\n");
        devfs_mk_cdev(MKDEV(TTYAUX_MAJOR, 2), S_IFCHR|S_IRUGO|S_IWUGO, "ptmx");
-       class_simple_device_add(tty_class, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx");
+       class_device_create(tty_class, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx");
 #endif
 
 #ifdef CONFIG_VT
@@ -2971,7 +3007,7 @@ static int __init tty_init(void)
            register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0)
                panic("Couldn't register /dev/tty0 driver\n");
        devfs_mk_cdev(MKDEV(TTY_MAJOR, 0), S_IFCHR|S_IRUSR|S_IWUSR, "vc/0");
-       class_simple_device_add(tty_class, MKDEV(TTY_MAJOR, 0), NULL, "tty0");
+       class_device_create(tty_class, MKDEV(TTY_MAJOR, 0), NULL, "tty0");
 
        vty_init();
 #endif