n_tty: Factor PARMRK from normal per-char i/o

Handle PARMRK processing on the slow per-char i/o path.

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 59c73ee32fbf1847ccf74779b1ad611c405bc076..adc06af3a0754f3f3546b7b31d3559e13e4c30b2 100644 (file)
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -1457,6 +1457,47 @@ static inline void n_tty_receive_char(struct tty_struct *tty, unsigned char c)
        n_tty_receive_char_special(tty, c);
 }
 
+static inline void
+n_tty_receive_char_fast(struct tty_struct *tty, unsigned char c)
+{
+       struct n_tty_data *ldata = tty->disc_data;
+
+       /*
+        * If the previous character was LNEXT, or we know that this
+        * character is not one of the characters that we'll have to
+        * handle specially, do shortcut processing to speed things
+        * up.
+        */
+       if (!test_bit(c, ldata->char_map) || ldata->lnext) {
+               ldata->lnext = 0;
+
+               if (tty->stopped && !tty->flow_stopped && I_IXON(tty) &&
+                   I_IXANY(tty)) {
+                       start_tty(tty);
+                       process_echoes(tty);
+               }
+
+               if (read_cnt(ldata) >= (N_TTY_BUF_SIZE - 1)) {
+                       /* beep if no space */
+                       if (L_ECHO(tty))
+                               process_output('\a', tty);
+                       return;
+               }
+               if (L_ECHO(tty)) {
+                       finish_erasing(ldata);
+                       /* Record the column of first canon char. */
+                       if (ldata->canon_head == ldata->read_head)
+                               echo_set_canon_col(ldata);
+                       echo_char(c, tty);
+                       commit_echoes(tty);
+               }
+               put_tty_queue(c, ldata);
+               return;
+       }
+
+       n_tty_receive_char_special(tty, c);
+}
+
 static inline void
 n_tty_receive_char_closing(struct tty_struct *tty, unsigned char c)
 {
@@ -1610,7 +1651,7 @@ n_tty_receive_buf_fast(struct tty_struct *tty, const unsigned char *cp,
                if (fp)
                        flag = *fp++;
                if (likely(flag == TTY_NORMAL))
-                       n_tty_receive_char(tty, *cp++);
+                       n_tty_receive_char_fast(tty, *cp++);
                else
                        n_tty_receive_char_flagged(tty, *cp++, flag);
        }
@@ -1629,7 +1670,7 @@ static void __receive_buf(struct tty_struct *tty, const unsigned char *cp,
        else if (tty->closing && !L_EXTPROC(tty))
                n_tty_receive_buf_closing(tty, cp, fp, count);
        else {
-               if (!preops)
+               if (!preops && !I_PARMRK(tty))
                        n_tty_receive_buf_fast(tty, cp, fp, count);
                else
                        n_tty_receive_buf_standard(tty, cp, fp, count);