n_tty: Move buffers into n_tty_data

Reduce pointer reloading and improve locality-of-reference;
allocate read_buf and echo_buf within struct n_tty_data.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index d6eba99785c45fe65ecb955296cbc9c903252eee..51cbdd22c18cec55b98de2a4e23b099f5a7a66cc 100644 (file)
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -105,9 +105,9 @@ struct n_tty_data {
        unsigned char lnext:1, erasing:1, raw:1, real_raw:1, icanon:1;
 
        /* shared by producer and consumer */
-       char *read_buf;
+       char read_buf[N_TTY_BUF_SIZE];
        DECLARE_BITMAP(read_flags, N_TTY_BUF_SIZE);
-       unsigned char *echo_buf;
+       unsigned char echo_buf[N_TTY_BUF_SIZE];
 
        int minimum_to_wake;
 
@@ -1695,9 +1695,7 @@ static void n_tty_close(struct tty_struct *tty)
        if (tty->link)
                n_tty_packet_mode_flush(tty);
 
-       kfree(ldata->read_buf);
-       kfree(ldata->echo_buf);
-       kfree(ldata);
+       vfree(ldata);
        tty->disc_data = NULL;
 }
 
@@ -1715,7 +1713,8 @@ static int n_tty_open(struct tty_struct *tty)
 {
        struct n_tty_data *ldata;
 
-       ldata = kzalloc(sizeof(*ldata), GFP_KERNEL);
+       /* Currently a malloc failure here can panic */
+       ldata = vmalloc(sizeof(*ldata));
        if (!ldata)
                goto err;
 
@@ -1723,16 +1722,14 @@ static int n_tty_open(struct tty_struct *tty)
        mutex_init(&ldata->atomic_read_lock);
        mutex_init(&ldata->output_lock);
 
-       /* These are ugly. Currently a malloc failure here can panic */
-       ldata->read_buf = kzalloc(N_TTY_BUF_SIZE, GFP_KERNEL);
-       ldata->echo_buf = kzalloc(N_TTY_BUF_SIZE, GFP_KERNEL);
-       if (!ldata->read_buf || !ldata->echo_buf)
-               goto err_free_bufs;
-
        tty->disc_data = ldata;
        reset_buffer_flags(tty->disc_data);
        ldata->column = 0;
+       ldata->canon_column = 0;
        ldata->minimum_to_wake = 1;
+       ldata->num_overrun = 0;
+       ldata->no_room = 0;
+       ldata->lnext = 0;
        tty->closing = 0;
        /* indicate buffer work may resume */
        clear_bit(TTY_LDISC_HALTED, &tty->flags);
@@ -1740,10 +1737,6 @@ static int n_tty_open(struct tty_struct *tty)
        tty_unthrottle(tty);
 
        return 0;
-err_free_bufs:
-       kfree(ldata->read_buf);
-       kfree(ldata->echo_buf);
-       kfree(ldata);
 err:
        return -ENOMEM;
 }