tty: Split the serial_core helpers for setserial into two

We want them split so that we can call them from setserial functionality
where we copy to/from user space and do the locking, but also from sysfs
where in future we'll want to came them within a sysfs context.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 87 insertions, 71 deletions

diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 5b308c87b68c..bb5f23603836 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -634,38 +634,44 @@ static void uart_unthrottle(struct tty_struct *tty)
                 uart_set_mctrl(port, TIOCM_RTS);
 }
 
-static int uart_get_info(struct uart_state *state,
-                         struct serial_struct __user *retinfo)
+static void uart_get_info(struct tty_port *port,
+                        struct uart_state *state,
+                        struct serial_struct *retinfo)
 {
         struct uart_port *uport = state->uart_port;
-        struct tty_port *port = &state->port;
-        struct serial_struct tmp;
-
-        memset(&tmp, 0, sizeof(tmp));
 
-        /* Ensure the state we copy is consistent and no hardware changes
-           occur as we go */
-        mutex_lock(&port->mutex);
+        memset(retinfo, 0, sizeof(retinfo));
 
-        tmp.type            = uport->type;
-        tmp.line            = uport->line;
-        tmp.port            = uport->iobase;
+        retinfo->type       = uport->type;
+        retinfo->line       = uport->line;
+        retinfo->port       = uport->iobase;
         if (HIGH_BITS_OFFSET)
-                tmp.port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
-        tmp.irq             = uport->irq;
-        tmp.flags           = uport->flags;
-        tmp.xmit_fifo_size  = uport->fifosize;
-        tmp.baud_base       = uport->uartclk / 16;
-        tmp.close_delay     = jiffies_to_msecs(port->close_delay) / 10;
-        tmp.closing_wait    = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
+                retinfo->port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
+        retinfo->irq                = uport->irq;
+        retinfo->flags      = uport->flags;
+        retinfo->xmit_fifo_size  = uport->fifosize;
+        retinfo->baud_base          = uport->uartclk / 16;
+        retinfo->close_delay        = jiffies_to_msecs(port->close_delay) / 10;
+        retinfo->closing_wait    = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
                                 ASYNC_CLOSING_WAIT_NONE :
                                 jiffies_to_msecs(port->closing_wait) / 10;
-        tmp.custom_divisor  = uport->custom_divisor;
-        tmp.hub6            = uport->hub6;
-        tmp.io_type         = uport->iotype;
-        tmp.iomem_reg_shift = uport->regshift;
-        tmp.iomem_base      = (void *)(unsigned long)uport->mapbase;
+        retinfo->custom_divisor  = uport->custom_divisor;
+        retinfo->hub6       = uport->hub6;
+        retinfo->io_type         = uport->iotype;
+        retinfo->iomem_reg_shift = uport->regshift;
+        retinfo->iomem_base      = (void *)(unsigned long)uport->mapbase;
+}
+
+static int uart_get_info_user(struct uart_state *state,
+                         struct serial_struct __user *retinfo)
+{
+        struct tty_port *port = &state->port;
+        struct serial_struct tmp;
 
+        /* Ensure the state we copy is consistent and no hardware changes
+           occur as we go */
+        mutex_lock(&port->mutex);
+        uart_get_info(port, state, &tmp);
         mutex_unlock(&port->mutex);
 
         if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
@@ -673,42 +679,30 @@ static int uart_get_info(struct uart_state *state,
         return 0;
 }
 
-static int uart_set_info(struct tty_struct *tty, struct uart_state *state,
-                         struct serial_struct __user *newinfo)
+static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
+                         struct uart_state *state,
+                         struct serial_struct *new_info)
 {
-        struct serial_struct new_serial;
         struct uart_port *uport = state->uart_port;
-        struct tty_port *port = &state->port;
         unsigned long new_port;
         unsigned int change_irq, change_port, closing_wait;
         unsigned int old_custom_divisor, close_delay;
         upf_t old_flags, new_flags;
         int retval = 0;
 
-        if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
-                return -EFAULT;
-
-        new_port = new_serial.port;
+        new_port = new_info->port;
         if (HIGH_BITS_OFFSET)
-                new_port += (unsigned long) new_serial.port_high << HIGH_BITS_OFFSET;
+                new_port += (unsigned long) new_info->port_high << HIGH_BITS_OFFSET;
 
-        new_serial.irq = irq_canonicalize(new_serial.irq);
-        close_delay = msecs_to_jiffies(new_serial.close_delay * 10);
-        closing_wait = new_serial.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
+        new_info->irq = irq_canonicalize(new_info->irq);
+        close_delay = msecs_to_jiffies(new_info->close_delay * 10);
+        closing_wait = new_info->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
                         ASYNC_CLOSING_WAIT_NONE :
-                        msecs_to_jiffies(new_serial.closing_wait * 10);
+                        msecs_to_jiffies(new_info->closing_wait * 10);
 
-        /*
-         * This semaphore protects port->count.  It is also
-         * very useful to prevent opens.  Also, take the
-         * port configuration semaphore to make sure that a
-         * module insertion/removal doesn't change anything
-         * under us.
-         */
-        mutex_lock(&port->mutex);
 
         change_irq  = !(uport->flags & UPF_FIXED_PORT)
-                && new_serial.irq != uport->irq;
+                && new_info->irq != uport->irq;
 
         /*
          * Since changing the 'type' of the port changes its resource
@@ -717,29 +711,29 @@ static int uart_set_info(struct tty_struct *tty, struct uart_state *state,
          */
         change_port = !(uport->flags & UPF_FIXED_PORT)
                 && (new_port != uport->iobase ||
-                    (unsigned long)new_serial.iomem_base != uport->mapbase ||
-                    new_serial.hub6 != uport->hub6 ||
-                    new_serial.io_type != uport->iotype ||
-                    new_serial.iomem_reg_shift != uport->regshift ||
-                    new_serial.type != uport->type);
+                    (unsigned long)new_info->iomem_base != uport->mapbase ||
+                    new_info->hub6 != uport->hub6 ||
+                    new_info->io_type != uport->iotype ||
+                    new_info->iomem_reg_shift != uport->regshift ||
+                    new_info->type != uport->type);
 
         old_flags = uport->flags;
-        new_flags = new_serial.flags;
+        new_flags = new_info->flags;
         old_custom_divisor = uport->custom_divisor;
 
         if (!capable(CAP_SYS_ADMIN)) {
                 retval = -EPERM;
                 if (change_irq || change_port ||
-                    (new_serial.baud_base != uport->uartclk / 16) ||
+                    (new_info->baud_base != uport->uartclk / 16) ||
                     (close_delay != port->close_delay) ||
                     (closing_wait != port->closing_wait) ||
-                    (new_serial.xmit_fifo_size &&
-                     new_serial.xmit_fifo_size != uport->fifosize) ||
+                    (new_info->xmit_fifo_size &&
+                     new_info->xmit_fifo_size != uport->fifosize) ||
                     (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
                         goto exit;
                 uport->flags = ((uport->flags & ~UPF_USR_MASK) |
                                (new_flags & UPF_USR_MASK));
-                uport->custom_divisor = new_serial.custom_divisor;
+                uport->custom_divisor = new_info->custom_divisor;
                 goto check_and_exit;
         }
 
@@ -747,10 +741,10 @@ static int uart_set_info(struct tty_struct *tty, struct uart_state *state,
          * Ask the low level driver to verify the settings.
          */
         if (uport->ops->verify_port)
-                retval = uport->ops->verify_port(uport, &new_serial);
+                retval = uport->ops->verify_port(uport, new_info);
 
-        if ((new_serial.irq >= nr_irqs) || (new_serial.irq < 0) ||
-            (new_serial.baud_base < 9600))
+        if ((new_info->irq >= nr_irqs) || (new_info->irq < 0) ||
+            (new_info->baud_base < 9600))
                 retval = -EINVAL;
 
         if (retval)
@@ -790,11 +784,11 @@ static int uart_set_info(struct tty_struct *tty, struct uart_state *state,
                         uport->ops->release_port(uport);
 
                 uport->iobase = new_port;
-                uport->type = new_serial.type;
-                uport->hub6 = new_serial.hub6;
-                uport->iotype = new_serial.io_type;
-                uport->regshift = new_serial.iomem_reg_shift;
-                uport->mapbase = (unsigned long)new_serial.iomem_base;
+                uport->type = new_info->type;
+                uport->hub6 = new_info->hub6;
+                uport->iotype = new_info->io_type;
+                uport->regshift = new_info->iomem_reg_shift;
+                uport->mapbase = (unsigned long)new_info->iomem_base;
 
                 /*
                  * Claim and map the new regions
@@ -835,16 +829,16 @@ static int uart_set_info(struct tty_struct *tty, struct uart_state *state,
         }
 
         if (change_irq)
-                uport->irq      = new_serial.irq;
+                uport->irq      = new_info->irq;
         if (!(uport->flags & UPF_FIXED_PORT))
-                uport->uartclk  = new_serial.baud_base * 16;
+                uport->uartclk  = new_info->baud_base * 16;
         uport->flags            = (uport->flags & ~UPF_CHANGE_MASK) |
                                  (new_flags & UPF_CHANGE_MASK);
-        uport->custom_divisor   = new_serial.custom_divisor;
+        uport->custom_divisor   = new_info->custom_divisor;
         port->close_delay     = close_delay;
         port->closing_wait    = closing_wait;
-        if (new_serial.xmit_fifo_size)
-                uport->fifosize = new_serial.xmit_fifo_size;
+        if (new_info->xmit_fifo_size)
+                uport->fifosize = new_info->xmit_fifo_size;
         if (port->tty)
                 port->tty->low_latency =
                         (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
@@ -873,6 +867,28 @@ static int uart_set_info(struct tty_struct *tty, struct uart_state *state,
         } else
                 retval = uart_startup(tty, state, 1);
  exit:
+        return retval;
+}
+
+static int uart_set_info_user(struct tty_struct *tty, struct uart_state *state,
+                         struct serial_struct __user *newinfo)
+{
+        struct serial_struct new_serial;
+        struct tty_port *port = &state->port;
+        int retval;
+
+        if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
+                return -EFAULT;
+
+        /*
+         * This semaphore protects port->count.  It is also
+         * very useful to prevent opens.  Also, take the
+         * port configuration semaphore to make sure that a
+         * module insertion/removal doesn't change anything
+         * under us.
+         */
+        mutex_lock(&port->mutex);
+        retval = uart_set_info(tty, port, state, &new_serial);
         mutex_unlock(&port->mutex);
         return retval;
 }
@@ -1115,11 +1131,11 @@ uart_ioctl(struct tty_struct *tty, unsigned int cmd,
          */
         switch (cmd) {
         case TIOCGSERIAL:
-                ret = uart_get_info(state, uarg);
+                ret = uart_get_info_user(state, uarg);
                 break;
 
         case TIOCSSERIAL:
-                ret = uart_set_info(tty, state, uarg);
+                ret = uart_set_info_user(tty, state, uarg);
                 break;
 
         case TIOCSERCONFIG: