5 files changed, 88 insertions, 128 deletions

diff --git a/arch/um/drivers/chan.h b/arch/um/drivers/chan.h
index 8df0fd9024dc..5078ec701c61 100644
--- a/arch/um/drivers/chan.h
+++ b/arch/um/drivers/chan.h
@@ -27,24 +27,24 @@ struct chan {
         void *data;
 };
 
-extern void chan_interrupt(struct list_head *chans, struct delayed_work *task,
+extern void chan_interrupt(struct line *line, struct delayed_work *task,
                            struct tty_struct *tty, int irq);
 extern int parse_chan_pair(char *str, struct line *line, int device,
                            const struct chan_opts *opts, char **error_out);
-extern int write_chan(struct list_head *chans, const char *buf, int len,
+extern int write_chan(struct chan *chan, const char *buf, int len,
                              int write_irq);
-extern int console_write_chan(struct list_head *chans, const char *buf, 
+extern int console_write_chan(struct chan *chan, const char *buf, 
                               int len);
 extern int console_open_chan(struct line *line, struct console *co);
-extern void deactivate_chan(struct list_head *chans, int irq);
-extern void reactivate_chan(struct list_head *chans, int irq);
-extern void chan_enable_winch(struct list_head *chans, struct tty_struct *tty);
+extern void deactivate_chan(struct chan *chan, int irq);
+extern void reactivate_chan(struct chan *chan, int irq);
+extern void chan_enable_winch(struct chan *chan, struct tty_struct *tty);
 extern int enable_chan(struct line *line);
 extern void close_chan(struct list_head *chans, int delay_free_irq);
-extern int chan_window_size(struct list_head *chans, 
+extern int chan_window_size(struct line *line, 
                              unsigned short *rows_out, 
                              unsigned short *cols_out);
-extern int chan_config_string(struct list_head *chans, char *str, int size,
+extern int chan_config_string(struct line *line, char *str, int size,
                               char **error_out);
 
 #endif
diff --git a/arch/um/drivers/chan_kern.c b/arch/um/drivers/chan_kern.c
index 390920d63a24..73d7bc018ab2 100644
--- a/arch/um/drivers/chan_kern.c
+++ b/arch/um/drivers/chan_kern.c
@@ -140,18 +140,10 @@ static int open_chan(struct list_head *chans)
         return err;
 }
 
-void chan_enable_winch(struct list_head *chans, struct tty_struct *tty)
+void chan_enable_winch(struct chan *chan, struct tty_struct *tty)
 {
-        struct list_head *ele;
-        struct chan *chan;
-
-        list_for_each(ele, chans) {
-                chan = list_entry(ele, struct chan, list);
-                if (chan->primary && chan->output && chan->ops->winch) {
-                        register_winch(chan->fd, tty);
-                        return;
-                }
-        }
+        if (chan && chan->primary && chan->ops->winch)
+                register_winch(chan->fd, tty);
 }
 
 int enable_chan(struct line *line)
@@ -258,72 +250,45 @@ void close_chan(struct list_head *chans, int delay_free_irq)
         }
 }
 
-void deactivate_chan(struct list_head *chans, int irq)
+void deactivate_chan(struct chan *chan, int irq)
 {
-        struct list_head *ele;
-
-        struct chan *chan;
-        list_for_each(ele, chans) {
-                chan = list_entry(ele, struct chan, list);
-
-                if (chan->enabled && chan->input)
-                        deactivate_fd(chan->fd, irq);
-        }
+        if (chan && chan->enabled)
+                deactivate_fd(chan->fd, irq);
 }
 
-void reactivate_chan(struct list_head *chans, int irq)
+void reactivate_chan(struct chan *chan, int irq)
 {
-        struct list_head *ele;
-        struct chan *chan;
-
-        list_for_each(ele, chans) {
-                chan = list_entry(ele, struct chan, list);
-
-                if (chan->enabled && chan->input)
-                        reactivate_fd(chan->fd, irq);
-        }
+        if (chan && chan->enabled)
+                reactivate_fd(chan->fd, irq);
 }
 
-int write_chan(struct list_head *chans, const char *buf, int len,
+int write_chan(struct chan *chan, const char *buf, int len,
                int write_irq)
 {
-        struct list_head *ele;
-        struct chan *chan = NULL;
         int n, ret = 0;
 
-        if (len == 0)
+        if (len == 0 || !chan || !chan->ops->write)
                 return 0;
 
-        list_for_each(ele, chans) {
-                chan = list_entry(ele, struct chan, list);
-                if (!chan->output || (chan->ops->write == NULL))
-                        continue;
-
-                n = chan->ops->write(chan->fd, buf, len, chan->data);
-                if (chan->primary) {
-                        ret = n;
-                        if ((ret == -EAGAIN) || ((ret >= 0) && (ret < len)))
-                                reactivate_fd(chan->fd, write_irq);
-                }
+        n = chan->ops->write(chan->fd, buf, len, chan->data);
+        if (chan->primary) {
+                ret = n;
+                if ((ret == -EAGAIN) || ((ret >= 0) && (ret < len)))
+                        reactivate_fd(chan->fd, write_irq);
         }
         return ret;
 }
 
-int console_write_chan(struct list_head *chans, const char *buf, int len)
+int console_write_chan(struct chan *chan, const char *buf, int len)
 {
-        struct list_head *ele;
-        struct chan *chan;
         int n, ret = 0;
 
-        list_for_each(ele, chans) {
-                chan = list_entry(ele, struct chan, list);
-                if (!chan->output || (chan->ops->console_write == NULL))
-                        continue;
+        if (!chan || !chan->ops->console_write)
+                return 0;
 
-                n = chan->ops->console_write(chan->fd, buf, len);
-                if (chan->primary)
-                        ret = n;
-        }
+        n = chan->ops->console_write(chan->fd, buf, len);
+        if (chan->primary)
+                ret = n;
         return ret;
 }
 
@@ -340,20 +305,24 @@ int console_open_chan(struct line *line, struct console *co)
         return 0;
 }
 
-int chan_window_size(struct list_head *chans, unsigned short *rows_out,
+int chan_window_size(struct line *line, unsigned short *rows_out,
                       unsigned short *cols_out)
 {
-        struct list_head *ele;
         struct chan *chan;
 
-        list_for_each(ele, chans) {
-                chan = list_entry(ele, struct chan, list);
-                if (chan->primary) {
-                        if (chan->ops->window_size == NULL)
-                                return 0;
-                        return chan->ops->window_size(chan->fd, chan->data,
-                                                      rows_out, cols_out);
-                }
+        chan = line->chan_in;
+        if (chan && chan->primary) {
+                if (chan->ops->window_size == NULL)
+                        return 0;
+                return chan->ops->window_size(chan->fd, chan->data,
+                                              rows_out, cols_out);
+        }
+        chan = line->chan_out;
+        if (chan && chan->primary) {
+                if (chan->ops->window_size == NULL)
+                        return 0;
+                return chan->ops->window_size(chan->fd, chan->data,
+                                              rows_out, cols_out);
         }
         return 0;
 }
@@ -429,21 +398,15 @@ static int chan_pair_config_string(struct chan *in, struct chan *out,
         return n;
 }
 
-int chan_config_string(struct list_head *chans, char *str, int size,
+int chan_config_string(struct line *line, char *str, int size,
                        char **error_out)
 {
-        struct list_head *ele;
-        struct chan *chan, *in = NULL, *out = NULL;
+        struct chan *in = line->chan_in, *out = line->chan_out;
 
-        list_for_each(ele, chans) {
-                chan = list_entry(ele, struct chan, list);
-                if (!chan->primary)
-                        continue;
-                if (chan->input)
-                        in = chan;
-                if (chan->output)
-                        out = chan;
-        }
+        if (in && !in->primary)
+                in = NULL;
+        if (out && !out->primary)
+                out = NULL;
 
         return chan_pair_config_string(in, out, str, size, error_out);
 }
@@ -589,39 +552,36 @@ int parse_chan_pair(char *str, struct line *line, int device,
         return 0;
 }
 
-void chan_interrupt(struct list_head *chans, struct delayed_work *task,
+void chan_interrupt(struct line *line, struct delayed_work *task,
                     struct tty_struct *tty, int irq)
 {
-        struct list_head *ele, *next;
-        struct chan *chan;
+        struct chan *chan = line->chan_in;
         int err;
         char c;
 
-        list_for_each_safe(ele, next, chans) {
-                chan = list_entry(ele, struct chan, list);
-                if (!chan->input || (chan->ops->read == NULL))
-                        continue;
-                do {
-                        if (tty && !tty_buffer_request_room(tty, 1)) {
-                                schedule_delayed_work(task, 1);
-                                goto out;
-                        }
-                        err = chan->ops->read(chan->fd, &c, chan->data);
-                        if (err > 0)
-                                tty_receive_char(tty, c);
-                } while (err > 0);
-
-                if (err == 0)
-                        reactivate_fd(chan->fd, irq);
-                if (err == -EIO) {
-                        if (chan->primary) {
-                                if (tty != NULL)
-                                        tty_hangup(tty);
-                                close_chan(chans, 1);
-                                return;
-                        }
-                        else close_one_chan(chan, 1);
+        if (!chan || !chan->ops->read)
+                goto out;
+
+        do {
+                if (tty && !tty_buffer_request_room(tty, 1)) {
+                        schedule_delayed_work(task, 1);
+                        goto out;
+                }
+                err = chan->ops->read(chan->fd, &c, chan->data);
+                if (err > 0)
+                        tty_receive_char(tty, c);
+        } while (err > 0);
+
+        if (err == 0)
+                reactivate_fd(chan->fd, irq);
+        if (err == -EIO) {
+                if (chan->primary) {
+                        if (tty != NULL)
+                                tty_hangup(tty);
+                        close_chan(&line->chan_list, 1);
+                        return;
                 }
+                else close_one_chan(chan, 1);
         }
  out:
         if (tty)
diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c
index 9ffade87a8cf..c1aa89cefaec 100644
--- a/arch/um/drivers/line.c
+++ b/arch/um/drivers/line.c
@@ -21,7 +21,7 @@ static irqreturn_t line_interrupt(int irq, void *data)
         struct line *line = chan->line;
 
         if (line)
-                chan_interrupt(&line->chan_list, &line->task, line->tty, irq);
+                chan_interrupt(line, &line->task, line->tty, irq);
         return IRQ_HANDLED;
 }
 
@@ -30,7 +30,7 @@ static void line_timer_cb(struct work_struct *work)
         struct line *line = container_of(work, struct line, task.work);
 
         if (!line->throttled)
-                chan_interrupt(&line->chan_list, &line->task, line->tty,
+                chan_interrupt(line, &line->task, line->tty,
                                line->driver->read_irq);
 }
 
@@ -145,7 +145,7 @@ static int flush_buffer(struct line *line)
                 /* line->buffer + LINE_BUFSIZE is the end of the buffer! */
                 count = line->buffer + LINE_BUFSIZE - line->head;
 
-                n = write_chan(&line->chan_list, line->head, count,
+                n = write_chan(line->chan_out, line->head, count,
                                line->driver->write_irq);
                 if (n < 0)
                         return n;
@@ -162,7 +162,7 @@ static int flush_buffer(struct line *line)
         }
 
         count = line->tail - line->head;
-        n = write_chan(&line->chan_list, line->head, count,
+        n = write_chan(line->chan_out, line->head, count,
                        line->driver->write_irq);
 
         if (n < 0)
@@ -206,7 +206,7 @@ int line_write(struct tty_struct *tty, const unsigned char *buf, int len)
         if (line->head != line->tail)
                 ret = buffer_data(line, buf, len);
         else {
-                n = write_chan(&line->chan_list, buf, len,
+                n = write_chan(line->chan_out, buf, len,
                                line->driver->write_irq);
                 if (n < 0) {
                         ret = n;
@@ -318,7 +318,7 @@ void line_throttle(struct tty_struct *tty)
 {
         struct line *line = tty->driver_data;
 
-        deactivate_chan(&line->chan_list, line->driver->read_irq);
+        deactivate_chan(line->chan_in, line->driver->read_irq);
         line->throttled = 1;
 }
 
@@ -327,7 +327,7 @@ void line_unthrottle(struct tty_struct *tty)
         struct line *line = tty->driver_data;
 
         line->throttled = 0;
-        chan_interrupt(&line->chan_list, &line->task, tty,
+        chan_interrupt(line, &line->task, tty,
                        line->driver->read_irq);
 
         /*
@@ -336,7 +336,7 @@ void line_unthrottle(struct tty_struct *tty)
          * again and we shouldn't turn the interrupt back on.
          */
         if (!line->throttled)
-                reactivate_chan(&line->chan_list, line->driver->read_irq);
+                reactivate_chan(line->chan_in, line->driver->read_irq);
 }
 
 static irqreturn_t line_write_interrupt(int irq, void *data)
@@ -428,11 +428,11 @@ int line_open(struct line *lines, struct tty_struct *tty)
         INIT_DELAYED_WORK(&line->task, line_timer_cb);
 
         if (!line->sigio) {
-                chan_enable_winch(&line->chan_list, tty);
+                chan_enable_winch(line->chan_out, tty);
                 line->sigio = 1;
         }
 
-        chan_window_size(&line->chan_list, &tty->winsize.ws_row,
+        chan_window_size(line, &tty->winsize.ws_row,
                          &tty->winsize.ws_col);
 out_unlock:
         mutex_unlock(&line->count_lock);
@@ -624,7 +624,7 @@ int line_get_config(char *name, struct line *lines, unsigned int num, char *str,
                 CONFIG_CHUNK(str, size, n, "none", 1);
         else if (line->tty == NULL)
                 CONFIG_CHUNK(str, size, n, line->init_str, 1);
-        else n = chan_config_string(&line->chan_list, str, size, error_out);
+        else n = chan_config_string(line, str, size, error_out);
         mutex_unlock(&line->count_lock);
 
         return n;
@@ -761,7 +761,7 @@ static irqreturn_t winch_interrupt(int irq, void *data)
         if (tty != NULL) {
                 line = tty->driver_data;
                 if (line != NULL) {
-                        chan_window_size(&line->chan_list, &tty->winsize.ws_row,
+                        chan_window_size(line, &tty->winsize.ws_row,
                                          &tty->winsize.ws_col);
                         kill_pgrp(tty->pgrp, SIGWINCH, 1);
                 }
diff --git a/arch/um/drivers/ssl.c b/arch/um/drivers/ssl.c
index d0b5ccf2379f..e09801a1327b 100644
--- a/arch/um/drivers/ssl.c
+++ b/arch/um/drivers/ssl.c
@@ -151,7 +151,7 @@ static void ssl_console_write(struct console *c, const char *string,
         unsigned long flags;
 
         spin_lock_irqsave(&line->lock, flags);
-        console_write_chan(&line->chan_list, string, len);
+        console_write_chan(line->chan_out, string, len);
         spin_unlock_irqrestore(&line->lock, flags);
 }
 
diff --git a/arch/um/drivers/stdio_console.c b/arch/um/drivers/stdio_console.c
index fe581209d629..7663541c372e 100644
--- a/arch/um/drivers/stdio_console.c
+++ b/arch/um/drivers/stdio_console.c
@@ -124,7 +124,7 @@ static void uml_console_write(struct console *console, const char *string,
         unsigned long flags;
 
         spin_lock_irqsave(&line->lock, flags);
-        console_write_chan(&line->chan_list, string, len);
+        console_write_chan(line->chan_out, string, len);
         spin_unlock_irqrestore(&line->lock, flags);
 }