return IRQ_HANDLED;
}
-static void line_timer_cb(void *arg)
+static void line_timer_cb(struct work_struct *work)
{
- struct line *line = arg;
+ struct line *line = container_of(work, struct line, task.work);
if(!line->throttled)
chan_interrupt(&line->chan_list, &line->task, line->tty,
/*XXX: copied from line_write, verify if it is correct!*/
if(tty->stopped)
return;
- //return 0;
spin_lock_irqsave(&line->lock, flags);
err = flush_buffer(line);
return ret;
}
-void line_set_termios(struct tty_struct *tty, struct termios * old)
+void line_set_termios(struct tty_struct *tty, struct ktermios * old)
{
/* nothing */
}
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.
+ *
+ * tty->count serves to decide whether the device should be enabled or
+ * disabled on the host. If it's equal to 1, 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)
{
- struct line *line;
+ struct line *line = &lines[tty->index];
int err = -ENODEV;
- line = &lines[tty->index];
- tty->driver_data = line;
+ spin_lock(&line->count_lock);
+ if(!line->valid)
+ goto out_unlock;
- /* The IRQ which takes this lock is not yet enabled and won't be run
- * before the end, so we don't need to use spin_lock_irq.*/
- spin_lock(&line->lock);
+ err = 0;
+ if(tty->count > 1)
+ goto out_unlock;
+
+ spin_unlock(&line->count_lock);
tty->driver_data = line;
line->tty = tty;
- if(!line->valid)
- goto out;
- if(tty->count == 1){
- /* Here the device is opened, if necessary, and interrupt
- * is registered.
- */
- enable_chan(line);
- INIT_WORK(&line->task, line_timer_cb, line);
+ enable_chan(line);
+ INIT_DELAYED_WORK(&line->task, line_timer_cb);
- if(!line->sigio){
- chan_enable_winch(&line->chan_list, tty);
- line->sigio = 1;
- }
-
- chan_window_size(&line->chan_list, &tty->winsize.ws_row,
- &tty->winsize.ws_col);
+ if(!line->sigio){
+ chan_enable_winch(&line->chan_list, tty);
+ line->sigio = 1;
}
- err = 0;
-out:
- spin_unlock(&line->lock);
+ chan_window_size(&line->chan_list, &tty->winsize.ws_row,
+ &tty->winsize.ws_col);
+
+ return err;
+
+out_unlock:
+ spin_unlock(&line->count_lock);
return err;
}
{
struct line *line = tty->driver_data;
- /* XXX: I assume this should be called in process context, not with
- * interrupts disabled!
- */
- spin_lock_irq(&line->lock);
+ /* 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;
/* We ignore the error anyway! */
flush_buffer(line);
- if(tty->count == 1){
- line->tty = NULL;
- tty->driver_data = NULL;
+ spin_lock(&line->count_lock);
+ if(!line->valid)
+ goto out_unlock;
- if(line->sigio){
- unregister_winch(tty);
- line->sigio = 0;
- }
+ if(tty->count > 1)
+ goto out_unlock;
+
+ spin_unlock(&line->count_lock);
+
+ line->tty = NULL;
+ tty->driver_data = NULL;
+
+ if(line->sigio){
+ unregister_winch(tty);
+ line->sigio = 0;
}
- spin_unlock_irq(&line->lock);
+ return;
+
+out_unlock:
+ spin_unlock(&line->count_lock);
}
void close_lines(struct line *lines, int nlines)
close_chan(&lines[i].chan_list, 0);
}
+static int setup_one_line(struct line *lines, int n, char *init, int init_prio,
+ char **error_out)
+{
+ struct line *line = &lines[n];
+ int err = -EINVAL;
+
+ spin_lock(&line->count_lock);
+
+ if(line->tty != NULL){
+ *error_out = "Device is already open";
+ goto out;
+ }
+
+ if (line->init_pri <= init_prio){
+ line->init_pri = init_prio;
+ if (!strcmp(init, "none"))
+ line->valid = 0;
+ else {
+ line->init_str = init;
+ line->valid = 1;
+ }
+ }
+ err = 0;
+out:
+ spin_unlock(&line->count_lock);
+ return err;
+}
+
/* Common setup code for both startup command line and mconsole initialization.
* @lines contains the array (of size @num) to modify;
* @init is the setup string;
+ * @error_out is an error string in the case of failure;
*/
-int line_setup(struct line *lines, unsigned int num, char *init)
+int line_setup(struct line *lines, unsigned int num, char *init,
+ char **error_out)
{
- int i, n;
+ int i, n, err;
char *end;
if(*init == '=') {
else {
n = simple_strtoul(init, &end, 0);
if(*end != '='){
- printk(KERN_ERR "line_setup failed to parse \"%s\"\n",
- init);
- return 0;
+ *error_out = "Couldn't parse device number";
+ return -EINVAL;
}
init = end;
}
init++;
if (n >= (signed int) num) {
- printk("line_setup - %d out of range ((0 ... %d) allowed)\n",
- n, num - 1);
- return 0;
+ *error_out = "Device number out of range";
+ return -EINVAL;
}
else if (n >= 0){
- if (lines[n].tty != NULL) {
- printk("line_setup - device %d is open\n", n);
- return 0;
- }
- if (lines[n].init_pri <= INIT_ONE){
- lines[n].init_pri = INIT_ONE;
- if (!strcmp(init, "none"))
- lines[n].valid = 0;
- else {
- lines[n].init_str = init;
- lines[n].valid = 1;
- }
- }
+ err = setup_one_line(lines, n, init, INIT_ONE, error_out);
+ if(err)
+ return err;
}
else {
for(i = 0; i < num; i++){
- if(lines[i].init_pri <= INIT_ALL){
- lines[i].init_pri = INIT_ALL;
- if(!strcmp(init, "none")) lines[i].valid = 0;
- else {
- lines[i].init_str = init;
- lines[i].valid = 1;
- }
- }
+ err = setup_one_line(lines, i, init, INIT_ALL,
+ error_out);
+ if(err)
+ return err;
}
}
return n == -1 ? num : n;
}
int line_config(struct line *lines, unsigned int num, char *str,
- const struct chan_opts *opts)
+ const struct chan_opts *opts, char **error_out)
{
struct line *line;
char *new;
int n;
if(*str == '='){
- printk("line_config - can't configure all devices from "
- "mconsole\n");
- return 1;
+ *error_out = "Can't configure all devices from mconsole";
+ return -EINVAL;
}
new = kstrdup(str, GFP_KERNEL);
if(new == NULL){
- printk("line_config - kstrdup failed\n");
- return 1;
+ *error_out = "Failed to allocate memory";
+ return -ENOMEM;
}
- n = line_setup(lines, num, new);
+ n = line_setup(lines, num, new, error_out);
if(n < 0)
- return 1;
+ return n;
line = &lines[n];
- return parse_chan_pair(line->init_str, line, n, opts);
+ return parse_chan_pair(line->init_str, line, n, opts, error_out);
}
int line_get_config(char *name, struct line *lines, unsigned int num, char *str,
line = &lines[dev];
- spin_lock(&line->lock);
+ spin_lock(&line->count_lock);
if(!line->valid)
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);
- spin_unlock(&line->lock);
+ spin_unlock(&line->count_lock);
return n;
}
return n;
}
-int line_remove(struct line *lines, unsigned int num, int n)
+int line_remove(struct line *lines, unsigned int num, int n, char **error_out)
{
int err;
char config[sizeof("conxxxx=none\0")];
sprintf(config, "%d=none", n);
- err = line_setup(lines, num, config);
+ err = line_setup(lines, num, config, error_out);
if(err >= 0)
err = 0;
return err;
}
-struct tty_driver *line_register_devfs(struct lines *set,
- struct line_driver *line_driver,
- const struct tty_operations *ops,
- struct line *lines, int nlines)
+struct tty_driver *register_lines(struct line_driver *line_driver,
+ const struct tty_operations *ops,
+ struct line *lines, int nlines)
{
int i;
struct tty_driver *driver = alloc_tty_driver(nlines);
void lines_init(struct line *lines, int nlines, struct chan_opts *opts)
{
struct line *line;
+ char *error;
int i;
for(i = 0; i < nlines; i++){
if(line->init_str == NULL)
printk("lines_init - kstrdup returned NULL\n");
- if(parse_chan_pair(line->init_str, line, i, opts)){
- printk("parse_chan_pair failed for device %d\n", i);
+ if(parse_chan_pair(line->init_str, line, i, opts, &error)){
+ printk("parse_chan_pair failed for device %d : %s\n",
+ i, error);
line->valid = 0;
}
}
line = tty->driver_data;
chan_window_size(&line->chan_list, &tty->winsize.ws_row,
&tty->winsize.ws_col);
- kill_pg(tty->pgrp, SIGWINCH, 1);
+ kill_pgrp(tty->pgrp, SIGWINCH, 1);
}
out:
if(winch->fd != -1)
git.samba.org / sfrench / cifs-2.6.git / blobdiff