- 根目录:
- arch
- um
- drivers
- chan_kern.c
/*
* Copyright (C) 2000 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com)
* Licensed under the GPL
*/
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include "chan.h"
#include "os.h"
#ifdef CONFIG_NOCONFIG_CHAN
static void *not_configged_init(char *str, int device,
const struct chan_opts *opts)
{
printk(KERN_ERR "Using a channel type which is configured out of "
"UML\n");
return NULL;
}
static int not_configged_open(int input, int output, int primary, void *data,
char **dev_out)
{
printk(KERN_ERR "Using a channel type which is configured out of "
"UML\n");
return -ENODEV;
}
static void not_configged_close(int fd, void *data)
{
printk(KERN_ERR "Using a channel type which is configured out of "
"UML\n");
}
static int not_configged_read(int fd, char *c_out, void *data)
{
printk(KERN_ERR "Using a channel type which is configured out of "
"UML\n");
return -EIO;
}
static int not_configged_write(int fd, const char *buf, int len, void *data)
{
printk(KERN_ERR "Using a channel type which is configured out of "
"UML\n");
return -EIO;
}
static int not_configged_console_write(int fd, const char *buf, int len)
{
printk(KERN_ERR "Using a channel type which is configured out of "
"UML\n");
return -EIO;
}
static int not_configged_window_size(int fd, void *data, unsigned short *rows,
unsigned short *cols)
{
printk(KERN_ERR "Using a channel type which is configured out of "
"UML\n");
return -ENODEV;
}
static void not_configged_free(void *data)
{
printk(KERN_ERR "Using a channel type which is configured out of "
"UML\n");
}
static const struct chan_ops not_configged_ops = {
.init = not_configged_init,
.open = not_configged_open,
.close = not_configged_close,
.read = not_configged_read,
.write = not_configged_write,
.console_write = not_configged_console_write,
.window_size = not_configged_window_size,
.free = not_configged_free,
.winch = 0,
};
#endif /* CONFIG_NOCONFIG_CHAN */
static void tty_receive_char(struct tty_struct *tty, char ch)
{
if (tty == NULL)
return;
if (I_IXON(tty) && !I_IXOFF(tty) && !tty->raw) {
if (ch == STOP_CHAR(tty)) {
stop_tty(tty);
return;
}
else if (ch == START_CHAR(tty)) {
start_tty(tty);
return;
}
}
tty_insert_flip_char(tty, ch, TTY_NORMAL);
}
static int open_one_chan(struct chan *chan)
{
int fd, err;
if (chan->opened)
return 0;
if (chan->ops->open == NULL)
fd = 0;
else fd = (*chan->ops->open)(chan->input, chan->output, chan->primary,
chan->data, &chan->dev);
if (fd < 0)
return fd;
err = os_set_fd_block(fd, 0);
if (err) {
(*chan->ops->close)(fd, chan->data);
return err;
}
chan->fd = fd;
chan->opened = 1;
return 0;
}
static int open_chan(struct list_head *chans)
{
struct list_head *ele;
struct chan *chan;
int ret, err = 0;
list_for_each(ele, chans) {
chan = list_entry(ele, struct chan, list);
ret = open_one_chan(chan);
if (chan->primary)
err = ret;
}
return err;
}
void chan_enable_winch(struct list_head *chans, 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;
}
}
}
int enable_chan(struct line *line)
{
struct list_head *ele;
struct chan *chan;
int err;
list_for_each(ele, &line->chan_list) {
chan = list_entry(ele, struct chan, list);
err = open_one_chan(chan);
if (err) {
if (chan->primary)
goto out_close;
continue;
}
if (chan->enabled)
continue;
err = line_setup_irq(chan->fd, chan->input, chan->output, line,
chan);
if (err)
goto out_close;
chan->enabled = 1;
}
return 0;
out_close:
close_chan(&line->chan_list, 0);
return err;
}
/* Items are added in IRQ context, when free_irq can't be called, and
* removed in process context, when it can.
* This handles interrupt sources which disappear, and which need to
* be permanently disabled. This is discovered in IRQ context, but
* the freeing of the IRQ must be done later.
*/
static DEFINE_SPINLOCK(irqs_to_free_lock);
static LIST_HEAD(irqs_to_free);
void free_irqs(void)
{
struct chan *chan;
LIST_HEAD(list);
struct list_head *ele;
unsigned long flags;
spin_lock_irqsave(&irqs_to_free_lock, flags);
list_splice_init(&irqs_to_free, &list);
spin_unlock_irqrestore(&irqs_to_free_lock, flags);
list_for_each(ele, &list) {
chan = list_entry(ele, struct chan, free_list);
if (chan->input && chan->enabled)
free_irq(chan->line->driver->read_irq, chan);
if (chan->output && chan->enabled)
free_irq(chan->line->driver->write_irq, chan);
chan->enabled = 0;
}
}
static void close_one_chan(struct chan *chan, int delay_free_irq)
{
unsigned long flags;
if (!chan->opened)
return;
if (delay_free_irq) {
spin_lock_irqsave(&irqs_to_free_lock, flags);
list_add(&chan->free_list, &irqs_to_free);
spin_unlock_irqrestore(&irqs_to_free_lock, flags);
}
else {
if (chan->input && chan->enabled)
free_irq(chan->line->driver->read_irq, chan);
if (chan->output && chan->enabled)
free_irq(chan->line->driver->write_irq, chan);
chan->enabled = 0;
}
if (chan->ops->close != NULL)
(*chan->ops->close)(chan->fd, chan->data);
chan->opened = 0;
chan->fd = -1;
}
void close_chan(struct list_head *chans, int delay_free_irq)
{
struct chan *chan;
/* Close in reverse order as open in case more than one of them
* refers to the same device and they save and restore that device's
* state. Then, the first one opened will have the original state,
* so it must be the last closed.
*/
list_for_each_entry_reverse(chan, chans, list) {
close_one_chan(chan, delay_free_irq);
}
}
void deactivate_chan(struct list_head *chans, 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);
}
}
void reactivate_chan(struct list_head *chans, 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);
}
}
int write_chan(struct list_head *chans, const char *buf, int len,
int write_irq)
{
struct list_head *ele;
struct chan *chan = NULL;
int n, ret = 0;
if (len == 0)
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);
}
}
return ret;
}
int console_write_chan(struct list_head *chans, 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;
n = chan->ops->console_write(chan->fd, buf, len);
if (chan->primary)
ret = n;
}
return ret;
}
int console_open_chan(struct line *line, struct console *co)
{
int err;
err = open_chan(&line->chan_list);
if (err)
return err;
printk(KERN_INFO "Console initialized on /dev/%s%d\n", co->name,
co->index);
return 0;
}
int chan_window_size(struct list_head *chans, 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);
}
}
return 0;
}
static void free_one_chan(struct chan *chan)
{
list_del(&chan->list);
close_one_chan(chan, 0);
if (chan->ops->free != NULL)
(*chan->ops->free)(chan->data);
if (chan->primary && chan->output)
ignore_sigio_fd(chan->fd);
kfree(chan);
}
static void free_chan(struct list_head *chans)
{
struct list_head *ele, *next;
struct chan *chan;
list_for_each_safe(ele, next, chans) {
chan = list_entry(ele, struct chan, list);
free_one_chan(chan);
}
}
static int one_chan_config_string(struct chan *chan, char *str, int size,
char **error_out)
{
int n = 0;
if (chan == NULL) {
CONFIG_CHUNK(str, size, n, "none", 1);
return n;
}
CONFIG_CHUNK(str, size, n, chan->ops->type, 0);
if (chan->dev == NULL) {
CONFIG_CHUNK(str, size, n, "", 1);
return n;
}
CONFIG_CHUNK(str, size, n, ":", 0);
CONFIG_CHUNK(str, size, n, chan->dev, 0);
return n;
}
static int chan_pair_config_string(struct chan *in, struct chan *out,
char *str, int size, char **error_out)
{
int n;
n = one_chan_config_string(in, str, size, error_out);
str += n;
size -= n;
if (in == out) {
CONFIG_CHUNK(str, size, n, "", 1);
return n;
}
CONFIG_CHUNK(str, size, n, ",", 1);
n = one_chan_config_string(out, str, size, error_out);
str += n;
size -= n;
CONFIG_CHUNK(str, size, n, "", 1);
return n;
}
int chan_config_string(struct list_head *chans, char *str, int size,
char **error_out)
{
struct list_head *ele;
struct chan *chan, *in = NULL, *out = NULL;
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;
}
return chan_pair_config_string(in, out, str, size, error_out);
}
struct chan_type {
char *key;
const struct chan_ops *ops;
};
static const struct chan_type chan_table[] = {
{ "fd", &fd_ops },
#ifdef CONFIG_NULL_CHAN
{ "null", &null_ops },
#else
{ "null", ¬_configged_ops },
#endif
#ifdef CONFIG_PORT_CHAN
{ "port", &port_ops },
#else
{ "port", ¬_configged_ops },
#endif
#ifdef CONFIG_PTY_CHAN
{ "pty", &pty_ops },
{ "pts", &pts_ops },
#else
{ "pty", ¬_configged_ops },
{ "pts", ¬_configged_ops },
#endif
#ifdef CONFIG_TTY_CHAN
{ "tty", &tty_ops },
#else
{ "tty", ¬_configged_ops },
#endif
#ifdef CONFIG_XTERM_CHAN
{ "xterm", &xterm_ops },
#else
{ "xterm", ¬_configged_ops },
#endif
};
static struct chan *parse_chan(struct line *line, char *str, int device,
const struct chan_opts *opts, char **error_out)
{
const struct chan_type *entry;
const struct chan_ops *ops;
struct chan *chan;
void *data;
int i;
ops = NULL;
data = NULL;
for(i = 0; i < ARRAY_SIZE(chan_table); i++) {
entry = &chan_table[i];
if (!strncmp(str, entry->key, strlen(entry->key))) {
ops = entry->ops;
str += strlen(entry->key);
break;
}
}
if (ops == NULL) {
*error_out = "No match for configured backends";
return NULL;
}
data = (*ops->init)(str, device, opts);
if (data == NULL) {
*error_out = "Configuration failed";
return NULL;
}
chan = kmalloc(sizeof(*chan), GFP_ATOMIC);
if (chan == NULL) {
*error_out = "Memory allocation failed";
return NULL;
}
*chan = ((struct chan) { .list = LIST_HEAD_INIT(chan->list),
.free_list =
LIST_HEAD_INIT(chan->free_list),
.line = line,
.primary = 1,
.input = 0,
.output = 0,
.opened = 0,
.enabled = 0,
.fd = -1,
.ops = ops,
.data = data });
return chan;
}
int parse_chan_pair(char *str, struct line *line, int device,
const struct chan_opts *opts, char **error_out)
{
struct list_head *chans = &line->chan_list;
struct chan *new;
char *in, *out;
if (!list_empty(chans)) {
free_chan(chans);
INIT_LIST_HEAD(chans);
}
out = strchr(str, ',');
if (out != NULL) {
in = str;
*out = '\0';
out++;
new = parse_chan(line, in, device, opts, error_out);
if (new == NULL)
return -1;
new->input = 1;
list_add(&new->list, chans);
new = parse_chan(line, out, device, opts, error_out);
if (new == NULL)
return -1;
list_add(&new->list, chans);
new->output = 1;
}
else {
new = parse_chan(line, str, device, opts, error_out);
if (new == NULL)
return -1;
list_add(&new->list, chans);
new->input = 1;
new->output = 1;
}
return 0;
}
void chan_interrupt(struct list_head *chans, struct delayed_work *task,
struct tty_struct *tty, int irq)
{
struct list_head *ele, *next;
struct chan *chan;
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);
}
}
out:
if (tty)
tty_flip_buffer_push(tty);
}