/*
* Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Licensed under the GPL
*/
#include "linux/irqreturn.h"
#include "linux/kd.h"
#include "linux/sched.h"
#include "linux/slab.h"
#include "chan.h"
#include "irq_kern.h"
#include "irq_user.h"
#include "kern_util.h"
#include "os.h"
#define LINE_BUFSIZE 4096
static irqreturn_t line_interrupt(int irq, void *data)
{
struct chan *chan = data;
struct line *line = chan->line;
if (line)
chan_interrupt(&line->chan_list, &line->task, line->tty, irq);
return IRQ_HANDLED;
}
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,
line->driver->read_irq);
}
/*
* Returns the free space inside the ring buffer of this line.
*
* Should be called while holding line->lock (this does not modify data).
*/
static int write_room(struct line *line)
{
int n;
if (line->buffer == NULL)
return LINE_BUFSIZE - 1;
/* This is for the case where the buffer is wrapped! */
n = line->head - line->tail;
if (n <= 0)
n += LINE_BUFSIZE; /* The other case */
return n - 1;
}
int line_write_room(struct tty_struct *tty)
{
struct line *line = tty->driver_data;
unsigned long flags;
int room;
spin_lock_irqsave(&line->lock, flags);
room = write_room(line);
spin_unlock_irqrestore(&line->lock, flags);
return room;
}
int line_chars_in_buffer(struct tty_struct *tty)
{
struct line *line = tty->driver_data;
unsigned long flags;
int ret;
spin_lock_irqsave(&line->lock, flags);
/* write_room subtracts 1 for the needed NULL, so we readd it.*/
ret = LINE_BUFSIZE - (write_room(line) + 1);
spin_unlock_irqrestore(&line->lock, flags);
return ret;
}
/*
* This copies the content of buf into the circular buffer associated with
* this line.
* The return value is the number of characters actually copied, i.e. the ones
* for which there was space: this function is not supposed to ever flush out
* the circular buffer.
*
* Must be called while holding line->lock!
*/
static int buffer_data(struct line *line, const char *buf, int len)
{
int end, room;
if (line->buffer == NULL) {
line->buffer = kmalloc(LINE_BUFSIZE, GFP_ATOMIC);
if (line->buffer == NULL) {
printk(KERN_ERR "buffer_data - atomic allocation "
"failed\n");
return 0;
}
line->head = line->buffer;
line->tail = line->buffer;
}
room = write_room(line);
len = (len > room) ? room : len;
end = line->buffer + LINE_BUFSIZE - line->tail;
if (len < end) {
memcpy(line->tail, buf, len);
line->tail += len;
}
else {
/* The circular buffer is wrapping */
memcpy(line->tail, buf, end);
buf += end;
memcpy(line->buffer, buf, len - end);
line->tail = line->buffer + len - end;
}
return len;
}
/*
* Flushes the ring buffer to the output channels. That is, write_chan is
* called, passing it line->head as buffer, and an appropriate count.
*
* On exit, returns 1 when the buffer is empty,
* 0 when the buffer is not empty on exit,
* and -errno when an error occurred.
*
* Must be called while holding line->lock!*/
static int flush_buffer(struct line *line)
{
int n, count;
if ((line->buffer == NULL) || (line->head == line->tail))
return 1;
if (line->tail < line->head) {
/* 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,
line->driver->write_irq);
if (n < 0)
return n;
if (n == count) {
/*
* We have flushed from ->head to buffer end, now we
* must flush only from the beginning to ->tail.
*/
line->head = line->buffer;
} else {
line->head += n;
return 0;
}
}
count = line->tail - line->head;
n = write_chan(&line->chan_list, line->head, count,
line->driver->write_irq);
if (n < 0)
return n;
line->head += n;
return line->head == line->tail;
}
void line_flush_buffer(struct tty_struct *tty)
{
struct line *line = tty->driver_data;
unsigned long flags;
spin_lock_irqsave(&line->lock, flags);
flush_buffer(line);
spin_unlock_irqrestore(&line->lock, flags);
}
/*
* We map both ->flush_chars and ->put_char (which go in pair) onto
* ->flush_buffer and ->write. Hope it's not that bad.
*/
void line_flush_chars(struct tty_struct *tty)
{
line_flush_buffer(tty);
}
int line_put_char(struct tty_struct *tty, unsigned char ch)
{
return line_write(tty, &ch, sizeof(ch));
}
int line_write(struct tty_struct *tty, const unsigned char *buf, int len)
{
struct line *line = tty->driver_data;
unsigned long flags;
int n, ret = 0;
spin_lock_irqsave(&line->lock, flags);
if (line->head != line->tail)
ret = buffer_data(line, buf, len);
else {
n = write_chan(&line->chan_list, buf, len,
line->driver->write_irq);
if (n < 0) {
ret = n;
goto out_up;
}
len -= n;
ret += n;
if (len > 0)
ret += buffer_data(line, buf + n, len);
}
out_up:
spin_unlock_irqrestore(&line->lock, flags);
return ret;
}
void line_set_termios(struct tty_struct *tty, struct ktermios * old)
{
/* nothing */
}
static const struct {
int cmd;
char *level;
char *name;
} tty_ioctls[] = {
/* don't print these, they flood the log ... */
{ TCGETS, NULL, "TCGETS" },
{ TCSETS, NULL, "TCSETS" },
{ TCSETSW, NULL, "TCSETSW" },
{ TCFLSH, NULL, "TCFLSH" },
{ TCSBRK, NULL, "TCSBRK" },
/* general tty stuff */
{ TCSETSF, KERN_DEBUG, "TCSETSF" },
{ TCGETA, KERN_DEBUG, "TCGETA" },
{ TIOCMGET, KERN_DEBUG, "TIOCMGET" },
{ TCSBRKP, KERN_DEBUG, "TCSBRKP" },
{ TIOCMSET, KERN_DEBUG, "TIOCMSET" },
/* linux-specific ones */
{ TIOCLINUX, KERN_INFO, "TIOCLINUX" },
{ KDGKBMODE, KERN_INFO, "KDGKBMODE" },
{ KDGKBTYPE, KERN_INFO, "KDGKBTYPE" },
{ KDSIGACCEPT, KERN_INFO, "KDSIGACCEPT" },
};
int line_ioctl(struct tty_struct *tty, unsigned int cmd,
unsigned long arg)
{
int ret;
int i;
ret = 0;
switch(cmd) {
#ifdef TIOCGETP
case TIOCGETP:
case TIOCSETP:
case TIOCSETN:
#endif
#ifdef TIOCGETC
case TIOCGETC:
case TIOCSETC:
#endif
#ifdef TIOCGLTC
case TIOCGLTC:
case TIOCSLTC:
#endif
/* Note: these are out of date as we now have TCGETS2 etc but this
whole lot should probably go away */
case TCGETS:
case TCSETSF:
case TCSETSW:
case TCSETS:
case TCGETA:
case TCSETAF:
case TCSETAW:
case TCSETA:
case TCXONC:
case TCFLSH:
case TIOCOUTQ:
case TIOCINQ:
case TIOCGLCKTRMIOS:
case TIOCSLCKTRMIOS:
case TIOCPKT:
case TIOCGSOFTCAR:
case TIOCSSOFTCAR:
return -ENOIOCTLCMD;
#if 0
case TCwhatever:
/* do something */
break;
#endif
default:
for (i = 0; i < ARRAY_SIZE(tty_ioctls); i++)
if (cmd == tty_ioctls[i].cmd)
break;
if (i == ARRAY_SIZE(tty_ioctls)) {
printk(KERN_ERR "%s: %s: unknown ioctl: 0x%x\n",
__func__, tty->name, cmd);
}
ret = -ENOIOCTLCMD;
break;
}
return ret;
}
void line_throttle(struct tty_struct *tty)
{
struct line *line = tty->driver_data;
deactivate_chan(&line->chan_list, line->driver->read_irq);
line->throttled = 1;
}
void line_unthrottle(struct tty_struct *tty)
{
struct line *line = tty->driver_data;
line->throttled = 0;
chan_interrupt(&line->chan_list, &line->task, tty,
line->driver->read_irq);
/*
* Maybe there is enough stuff pending that calling the interrupt
* throttles us again. In this case, line->throttled will be 1
* again and we shouldn't turn the interrupt back on.
*/
if (!line->throttled)
reactivate_chan(&line->chan_list, line->driver->read_irq);
}
static irqreturn_t line_write_interrupt(int irq, void *data)
{
struct chan *chan = data;
struct line *line = chan->line;
struct tty_struct *tty = line->tty;
int err;
/*
* Interrupts are disabled here because we registered the interrupt with
* IRQF_DISABLED (see line_setup_irq).
*/
spin_lock(&line->lock);
err = flush_buffer(line);
if (err == 0) {
return IRQ_NONE;
} else if (err < 0) {
line->head = line->buffer;
line->tail = line->buffer;
}
spin_unlock(&line->lock);
if (tty == NULL)
return IRQ_NONE;
tty_wakeup(tty);
return IRQ_HANDLED;
}
int line_setup_irq(int fd, int input, int output, struct line *line, void *data)
{
const struct line_driver *driver = line->driver;
int err = 0, flags = IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM;
if (input)
err = um_request_irq(driver->read_irq, fd, IRQ_READ,
line_interrupt, flags,
driver->read_irq_name, data);
if (err)
return err;
if (output)
err = um_request_irq(driver->write_irq, fd, IRQ_WRITE,
line_write_interrupt, flags,
driver->write_irq_name, data);
line->have_irq = 1;
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)
{
struct line *line = &lines[tty->index];
int err = -ENODEV;
spin_lock(&line->count_lock);
if (!line->valid)
goto out_unlock;
err = 0;
if (line->count++)
goto out_unlock;
BUG_ON(tty->driver_data);
tty->driver_data = line;
line->tty = tty;
spin_unlock(&line->count_lock);
err = enable_chan(line);
if (err) /* line_close() will be called by our caller */
return err;
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);
return 0;
out_unlock:
spin_unlock(&line->count_lock);
return err;
}
static void unregister_winch(struct tty_struct *tty);
void line_close(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;
/* We ignore the error anyway! */
flush_buffer(line);
spin_lock(&line->count_lock);
BUG_ON(!line->valid);
if (--line->count)
goto out_unlock;
line->tty = NULL;
tty->driver_data = NULL;
spin_unlock(&line->count_lock);
if (line->sigio) {
unregister_winch(tty);
line->sigio = 0;
}
return;
out_unlock:
spin_unlock(&line->count_lock);
}
void close_lines(struct line *lines, int nlines)
{
int i;
for(i = 0; i < nlines; i++)
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->count) {
*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,
char **error_out)
{
int i, n, err;
char *end;
if (*init == '=') {
/*
* We said con=/ssl= instead of con#=, so we are configuring all
* consoles at once.
*/
n = -1;
}
else {
n = simple_strtoul(init, &end, 0);
if (*end != '=') {
*error_out = "Couldn't parse device number";
return -EINVAL;
}
init = end;
}
init++;
if (n >= (signed int) num) {
*error_out = "Device number out of range";
return -EINVAL;
}
else if (n >= 0) {
err = setup_one_line(lines, n, init, INIT_ONE, error_out);
if (err)
return err;
}
else {
for(i = 0; i < num; i++) {
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, char **error_out)
{
struct line *line;
char *new;
int n;
if (*str == '=') {
*error_out = "Can't configure all devices from mconsole";
return -EINVAL;
}
new = kstrdup(str, GFP_KERNEL);
if (new == NULL) {
*error_out = "Failed to allocate memory";
return -ENOMEM;
}
n = line_setup(lines, num, new, error_out);
if (n < 0)
return n;
line = &lines[n];
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,
int size, char **error_out)
{
struct line *line;
char *end;
int dev, n = 0;
dev = simple_strtoul(name, &end, 0);
if ((*end != '\0') || (end == name)) {
*error_out = "line_get_config failed to parse device number";
return 0;
}
if ((dev < 0) || (dev >= num)) {
*error_out = "device number out of range";
return 0;
}
line = &lines[dev];
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->count_lock);
return n;
}
int line_id(char **str, int *start_out, int *end_out)
{
char *end;
int n;
n = simple_strtoul(*str, &end, 0);
if ((*end != '\0') || (end == *str))
return -1;
*str = end;
*start_out = n;
*end_out = n;
return 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, error_out);
if (err >= 0)
err = 0;
return err;
}
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);
if (!driver)
return NULL;
driver->driver_name = line_driver->name;
driver->name = line_driver->device_name;
driver->major = line_driver->major;
driver->minor_start = line_driver->minor_start;
driver->type = line_driver->type;
driver->subtype = line_driver->subtype;
driver->flags = TTY_DRIVER_REAL_RAW;
driver->init_termios = tty_std_termios;
tty_set_operations(driver, ops);
if (tty_register_driver(driver)) {
printk(KERN_ERR "register_lines : can't register %s driver\n",
line_driver->name);
put_tty_driver(driver);
return NULL;
}
for(i = 0; i < nlines; i++) {
if (!lines[i].valid)
tty_unregister_device(driver, i);
}
mconsole_register_dev(&line_driver->mc);
return driver;
}
static DEFINE_SPINLOCK(winch_handler_lock);
static LIST_HEAD(winch_handlers);
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++) {
line = &lines[i];
INIT_LIST_HEAD(&line->chan_list);
if (line->init_str == NULL)
continue;
line->init_str = kstrdup(line->init_str, GFP_KERNEL);
if (line->init_str == NULL)
printk(KERN_ERR "lines_init - kstrdup returned NULL\n");
if (parse_chan_pair(line->init_str, line, i, opts, &error)) {
printk(KERN_ERR "parse_chan_pair failed for "
"device %d : %s\n", i, error);
line->valid = 0;
}
}
}
struct winch {
struct list_head list;
int fd;
int tty_fd;
int pid;
struct tty_struct *tty;
unsigned long stack;
struct work_struct work;
};
static void __free_winch(struct work_struct *work)
{
struct winch *winch = container_of(work, struct winch, work);
free_irq(WINCH_IRQ, winch);
if (winch->pid != -1)
os_kill_process(winch->pid, 1);
if (winch->stack != 0)
free_stack(winch->stack, 0);
kfree(winch);
}
static void free_winch(struct winch *winch)
{
int fd = winch->fd;
winch->fd = -1;
if (fd != -1)
os_close_file(fd);
list_del(&winch->list);
__free_winch(&winch->work);
}
static irqreturn_t winch_interrupt(int irq, void *data)
{
struct winch *winch = data;
struct tty_struct *tty;
struct line *line;
int fd = winch->fd;
int err;
char c;
if (fd != -1) {
err = generic_read(fd, &c, NULL);
if (err < 0) {
if (err != -EAGAIN) {
winch->fd = -1;
list_del(&winch->list);
os_close_file(fd);
printk(KERN_ERR "winch_interrupt : "
"read failed, errno = %d\n", -err);
printk(KERN_ERR "fd %d is losing SIGWINCH "
"support\n", winch->tty_fd);
INIT_WORK(&winch->work, __free_winch);
schedule_work(&winch->work);
return IRQ_HANDLED;
}
goto out;
}
}
tty = winch->tty;
if (tty != NULL) {
line = tty->driver_data;
if (line != NULL) {
chan_window_size(&line->chan_list, &tty->winsize.ws_row,
&tty->winsize.ws_col);
kill_pgrp(tty->pgrp, SIGWINCH, 1);
}
}
out:
if (winch->fd != -1)
reactivate_fd(winch->fd, WINCH_IRQ);
return IRQ_HANDLED;
}
void register_winch_irq(int fd, int tty_fd, int pid, struct tty_struct *tty,
unsigned long stack)
{
struct winch *winch;
winch = kmalloc(sizeof(*winch), GFP_KERNEL);
if (winch == NULL) {
printk(KERN_ERR "register_winch_irq - kmalloc failed\n");
goto cleanup;
}
*winch = ((struct winch) { .list = LIST_HEAD_INIT(winch->list),
.fd = fd,
.tty_fd = tty_fd,
.pid = pid,
.tty = tty,
.stack = stack });
if (um_request_irq(WINCH_IRQ, fd, IRQ_READ, winch_interrupt,
IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM,
"winch", winch) < 0) {
printk(KERN_ERR "register_winch_irq - failed to register "
"IRQ\n");
goto out_free;
}
spin_lock(&winch_handler_lock);
list_add(&winch->list, &winch_handlers);
spin_unlock(&winch_handler_lock);
return;
out_free:
kfree(winch);
cleanup:
os_kill_process(pid, 1);
os_close_file(fd);
if (stack != 0)
free_stack(stack, 0);
}
static void unregister_winch(struct tty_struct *tty)
{
struct list_head *ele, *next;
struct winch *winch;
spin_lock(&winch_handler_lock);
list_for_each_safe(ele, next, &winch_handlers) {
winch = list_entry(ele, struct winch, list);
if (winch->tty == tty) {
free_winch(winch);
break;
}
}
spin_unlock(&winch_handler_lock);
}
static void winch_cleanup(void)
{
struct list_head *ele, *next;
struct winch *winch;
spin_lock(&winch_handler_lock);
list_for_each_safe(ele, next, &winch_handlers) {
winch = list_entry(ele, struct winch, list);
free_winch(winch);
}
spin_unlock(&winch_handler_lock);
}
__uml_exitcall(winch_cleanup);
char *add_xterm_umid(char *base)
{
char *umid, *title;
int len;
umid = get_umid();
if (*umid == '\0')
return base;
len = strlen(base) + strlen(" ()") + strlen(umid) + 1;
title = kmalloc(len, GFP_KERNEL);
if (title == NULL) {
printk(KERN_ERR "Failed to allocate buffer for xterm title\n");
return base;
}
snprintf(title, len, "%s (%s)", base, umid);
return title;
}
