[PATCH 5/6] um: fully use tty_port

From: Richard Weinberger
Date: Mon Jun 04 2012 - 16:28:22 EST


... use all tty_port helpers

Signed-off-by: Richard Weinberger <richard@xxxxxx>
---
arch/um/drivers/line.c | 102 +++++++++++++++++----------------------
arch/um/drivers/line.h | 6 ++-
arch/um/drivers/ssl.c | 15 ++----
arch/um/drivers/stdio_console.c | 20 ++++----
4 files changed, 65 insertions(+), 78 deletions(-)

diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c
index 131129a..95d5e78 100644
--- a/arch/um/drivers/line.c
+++ b/arch/um/drivers/line.c
@@ -296,43 +296,14 @@ int line_setup_irq(int fd, int input, int output, struct line *line, void *data)
return err;
}

-/*
- * Normally, a driver like this can rely mostly on the tty layer
- * locking, particularly when it comes to the driver structure.
- * However, in this case, mconsole requests can come in "from the
- * side", and race with opens and closes.
- *
- * mconsole config requests will want to be sure the device isn't in
- * use, and get_config, open, and close will want a stable
- * configuration. The checking and modification of the configuration
- * is done under a spinlock. Checking whether the device is in use is
- * line->tty->count > 1, also under the spinlock.
- *
- * line->count serves to decide whether the device should be enabled or
- * disabled on the host. If it's equal to 0, then we are doing the
- * first open or last close. Otherwise, open and close just return.
- */
-
-int line_open(struct line *lines, struct tty_struct *tty)
+static int line_activate(struct tty_port *port, struct tty_struct *tty)
{
- struct line *line = &lines[tty->index];
- int err = -ENODEV;
-
- mutex_lock(&line->count_lock);
- if (!line->valid)
- goto out_unlock;
-
- err = 0;
- if (line->port.count++)
- goto out_unlock;
-
- BUG_ON(tty->driver_data);
- tty->driver_data = line;
- tty_port_tty_set(&line->port, tty);
+ int ret;
+ struct line *line = tty->driver_data;

- err = enable_chan(line);
- if (err) /* line_close() will be called by our caller */
- goto out_unlock;
+ ret = enable_chan(line);
+ if (ret)
+ return ret;

if (!line->sigio) {
chan_enable_winch(line->chan_out, tty);
@@ -340,44 +311,60 @@ int line_open(struct line *lines, struct tty_struct *tty)
}

chan_window_size(line, &tty->winsize.ws_row,
- &tty->winsize.ws_col);
-out_unlock:
- mutex_unlock(&line->count_lock);
- return err;
+ &tty->winsize.ws_col);
+
+ return 0;
}

-static void unregister_winch(struct tty_struct *tty);
+static const struct tty_port_operations line_port_ops = {
+ .activate = line_activate,
+};

-void line_close(struct tty_struct *tty, struct file * filp)
+int line_open(struct tty_struct *tty, struct file *filp)
{
struct line *line = tty->driver_data;

- /*
- * If line_open fails (and tty->driver_data is never set),
- * tty_open will call line_close. So just return in this case.
- */
- if (line == NULL)
- return;
+ return tty_port_open(&line->port, tty, filp);
+}

- /* We ignore the error anyway! */
- flush_buffer(line);
+int line_install(struct tty_driver *driver, struct tty_struct *tty,
+ struct line *line)
+{
+ int ret;

- mutex_lock(&line->count_lock);
- BUG_ON(!line->valid);
+ ret = tty_standard_install(driver, tty);
+ if (ret)
+ return ret;
+
+ tty->driver_data = line;

- if (--line->port.count)
- goto out_unlock;
+ return 0;
+}
+
+static void unregister_winch(struct tty_struct *tty);

- tty_port_tty_set(&line->port, NULL);
- tty->driver_data = NULL;
+void line_cleanup(struct tty_struct *tty)
+{
+ struct line *line = tty->driver_data;

if (line->sigio) {
unregister_winch(tty);
line->sigio = 0;
}
+}

-out_unlock:
- mutex_unlock(&line->count_lock);
+void line_close(struct tty_struct *tty, struct file * filp)
+{
+ struct line *line = tty->driver_data;
+
+ tty_port_close(&line->port, tty, filp);
+}
+
+void line_hangup(struct tty_struct *tty)
+{
+ struct line *line = tty->driver_data;
+
+ tty_port_hangup(&line->port);
}

void close_lines(struct line *lines, int nlines)
@@ -589,6 +576,7 @@ int register_lines(struct line_driver *line_driver,

for (i = 0; i < nlines; i++) {
tty_port_init(&lines[i].port);
+ lines[i].port.ops = &line_port_ops;
spin_lock_init(&lines[i].lock);
mutex_init(&lines[i].count_lock);
lines[i].driver = line_driver;
diff --git a/arch/um/drivers/line.h b/arch/um/drivers/line.h
index 6c3b252..ad00f3e 100644
--- a/arch/um/drivers/line.h
+++ b/arch/um/drivers/line.h
@@ -58,7 +58,11 @@ struct line {
};

extern void line_close(struct tty_struct *tty, struct file * filp);
-extern int line_open(struct line *lines, struct tty_struct *tty);
+extern int line_open(struct tty_struct *tty, struct file *filp);
+extern int line_install(struct tty_driver *driver, struct tty_struct *tty,
+ struct line *line);
+extern void line_cleanup(struct tty_struct *tty);
+extern void line_hangup(struct tty_struct *tty);
extern int line_setup(char **conf, unsigned nlines, char **def,
char *init, char *name);
extern int line_write(struct tty_struct *tty, const unsigned char *buf,
diff --git a/arch/um/drivers/ssl.c b/arch/um/drivers/ssl.c
index cba95d9..7e86f00 100644
--- a/arch/um/drivers/ssl.c
+++ b/arch/um/drivers/ssl.c
@@ -87,19 +87,13 @@ static int ssl_remove(int n, char **error_out)
error_out);
}

-static int ssl_open(struct tty_struct *tty, struct file *filp)
+static int ssl_install(struct tty_driver *driver, struct tty_struct *tty)
{
- int err = line_open(serial_lines, tty);
-
- if (err)
- printk(KERN_ERR "Failed to open serial line %d, err = %d\n",
- tty->index, err);
-
- return err;
+ return line_install(driver, tty, &serial_lines[tty->index]);
}

static const struct tty_operations ssl_ops = {
- .open = ssl_open,
+ .open = line_open,
.close = line_close,
.write = line_write,
.put_char = line_put_char,
@@ -110,6 +104,9 @@ static const struct tty_operations ssl_ops = {
.set_termios = line_set_termios,
.throttle = line_throttle,
.unthrottle = line_unthrottle,
+ .install = ssl_install,
+ .cleanup = line_cleanup,
+ .hangup = line_hangup,
};

/* Changed by ssl_init and referenced by ssl_exit, which are both serialized
diff --git a/arch/um/drivers/stdio_console.c b/arch/um/drivers/stdio_console.c
index 5cefdba..929b99a 100644
--- a/arch/um/drivers/stdio_console.c
+++ b/arch/um/drivers/stdio_console.c
@@ -89,21 +89,17 @@ static int con_remove(int n, char **error_out)
return line_remove(vts, ARRAY_SIZE(vts), n, error_out);
}

-static int con_open(struct tty_struct *tty, struct file *filp)
-{
- int err = line_open(vts, tty);
- if (err)
- printk(KERN_ERR "Failed to open console %d, err = %d\n",
- tty->index, err);
-
- return err;
-}
-
/* Set in an initcall, checked in an exitcall */
static int con_init_done = 0;

+static int con_install(struct tty_driver *driver, struct tty_struct *tty)
+{
+ return line_install(driver, tty, &vts[tty->index]);
+}
+
static const struct tty_operations console_ops = {
- .open = con_open,
+ .open = line_open,
+ .install = con_install,
.close = line_close,
.write = line_write,
.put_char = line_put_char,
@@ -114,6 +110,8 @@ static const struct tty_operations console_ops = {
.set_termios = line_set_termios,
.throttle = line_throttle,
.unthrottle = line_unthrottle,
+ .cleanup = line_cleanup,
+ .hangup = line_hangup,
};

static void uml_console_write(struct console *console, const char *string,
--
1.7.7.3

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