swh:1:snp:173f8deb0c56c557784b4fd217e7608ac6197844
Tip revision: 02b3e4e2d71b6058ec11cc01c72ac651eb3ded2b authored by Linus Torvalds on 28 August 2005, 23:41:01 UTC
Linux v2.6.13
Linux v2.6.13
Tip revision: 02b3e4e
line.c
/*
* Copyright (C) 2001, 2002 Jeff Dike (jdike@karaya.com)
* Licensed under the GPL
*/
#include "linux/sched.h"
#include "linux/slab.h"
#include "linux/list.h"
#include "linux/kd.h"
#include "linux/interrupt.h"
#include "linux/devfs_fs_kernel.h"
#include "asm/uaccess.h"
#include "chan_kern.h"
#include "irq_user.h"
#include "line.h"
#include "kern.h"
#include "user_util.h"
#include "kern_util.h"
#include "os.h"
#include "irq_kern.h"
#define LINE_BUFSIZE 4096
static irqreturn_t line_interrupt(int irq, void *data, struct pt_regs *unused)
{
struct tty_struct *tty = data;
struct line *line = tty->driver_data;
if (line)
chan_interrupt(&line->chan_list, &line->task, tty, irq);
return IRQ_HANDLED;
}
static void line_timer_cb(void *arg)
{
struct tty_struct *tty = arg;
struct line *line = tty->driver_data;
line_interrupt(line->driver->read_irq, arg, NULL);
}
/* Returns the free space inside the ring buffer of this line.
*
* Should be called while holding line->lock (this does not modify datas).
*/
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 + n; /* 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;
if (tty->stopped)
return 0;
spin_lock_irqsave(&line->lock, flags);
room = write_room(line);
spin_unlock_irqrestore(&line->lock, flags);
/*XXX: Warning to remove */
if (0 == room)
printk(KERN_DEBUG "%s: %s: no room left in buffer\n",
__FUNCTION__,tty->name);
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("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;
int err;
/*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);
/*if (err == 1)
err = 0;*/
spin_unlock_irqrestore(&line->lock, flags);
//return err;
}
/* 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);
}
void line_put_char(struct tty_struct *tty, unsigned char ch)
{
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, err, ret = 0;
if(tty->stopped)
return 0;
spin_lock_irqsave(&line->lock, flags);
if (line->head != line->tail) {
ret = buffer_data(line, buf, len);
err = flush_buffer(line);
if (err <= 0 && (err != -EAGAIN || !ret))
ret = err;
} 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 termios * old)
{
/* nothing */
}
static 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, struct file * file,
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
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)) {
if (NULL != tty_ioctls[i].level)
printk("%s%s: %s: ioctl %s called\n",
tty_ioctls[i].level, __FUNCTION__,
tty->name, tty_ioctls[i].name);
} else {
printk(KERN_ERR "%s: %s: unknown ioctl: 0x%x\n",
__FUNCTION__, tty->name, cmd);
}
ret = -ENOIOCTLCMD;
break;
}
return ret;
}
static irqreturn_t line_write_interrupt(int irq, void *data,
struct pt_regs *unused)
{
struct tty_struct *tty = data;
struct line *line = tty->driver_data;
int err;
/* Interrupts are enabled here because we registered the interrupt with
* SA_INTERRUPT (see line_setup_irq).*/
spin_lock_irq(&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_irq(&line->lock);
if(tty == NULL)
return IRQ_NONE;
if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags) &&
(tty->ldisc.write_wakeup != NULL))
(tty->ldisc.write_wakeup)(tty);
/* BLOCKING mode
* In blocking mode, everything sleeps on tty->write_wait.
* Sleeping in the console driver would break non-blocking
* writes.
*/
if (waitqueue_active(&tty->write_wait))
wake_up_interruptible(&tty->write_wait);
return IRQ_HANDLED;
}
int line_setup_irq(int fd, int input, int output, struct tty_struct *tty)
{
struct line *line = tty->driver_data;
struct line_driver *driver = line->driver;
int err = 0, flags = SA_INTERRUPT | SA_SHIRQ | SA_SAMPLE_RANDOM;
if (input)
err = um_request_irq(driver->read_irq, fd, IRQ_READ,
line_interrupt, flags,
driver->read_irq_name, tty);
if (err)
return err;
if (output)
err = um_request_irq(driver->write_irq, fd, IRQ_WRITE,
line_write_interrupt, flags,
driver->write_irq_name, tty);
line->have_irq = 1;
return err;
}
void line_disable(struct tty_struct *tty, int current_irq)
{
struct line *line = tty->driver_data;
if(!line->have_irq)
return;
if(line->driver->read_irq == current_irq)
free_irq_later(line->driver->read_irq, tty);
else {
free_irq(line->driver->read_irq, tty);
}
if(line->driver->write_irq == current_irq)
free_irq_later(line->driver->write_irq, tty);
else {
free_irq(line->driver->write_irq, tty);
}
line->have_irq = 0;
}
int line_open(struct line *lines, struct tty_struct *tty,
struct chan_opts *opts)
{
struct line *line;
int err = 0;
line = &lines[tty->index];
tty->driver_data = line;
/* 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);
if (tty->count == 1) {
if (!line->valid) {
err = -ENODEV;
goto out;
}
if (list_empty(&line->chan_list)) {
err = parse_chan_pair(line->init_str, &line->chan_list,
line->init_pri, tty->index, opts);
if(err) goto out;
err = open_chan(&line->chan_list);
if(err) goto out;
}
/* Here the interrupt is registered.*/
enable_chan(&line->chan_list, tty);
INIT_WORK(&line->task, line_timer_cb, tty);
}
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);
line->count++;
out:
spin_unlock(&line->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;
/* XXX: I assume this should be called in process context, not with
* interrupts disabled!
*/
spin_lock_irq(&line->lock);
/* We ignore the error anyway! */
flush_buffer(line);
line->count--;
if (tty->count == 1) {
line_disable(tty, -1);
tty->driver_data = NULL;
}
if((line->count == 0) && line->sigio){
unregister_winch(tty);
line->sigio = 0;
}
spin_unlock_irq(&line->lock);
}
void close_lines(struct line *lines, int nlines)
{
int i;
for(i = 0; i < nlines; i++)
close_chan(&lines[i].chan_list);
}
/* Common setup code for both startup command line and mconsole initialization.
* @lines contains the the array (of size @num) to modify;
* @init is the setup string;
* @all_allowed is a boolean saying if we can setup the whole @lines
* at once. For instance, it will be usually true for startup init. (where we
* can use con=xterm) and false for mconsole.*/
int line_setup(struct line *lines, unsigned int num, char *init, int all_allowed)
{
int i, n;
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 != '='){
printk(KERN_ERR "line_setup failed to parse \"%s\"\n",
init);
return 0;
}
init = end;
}
init++;
if (n >= (signed int) num) {
printk("line_setup - %d out of range ((0 ... %d) allowed)\n",
n, num - 1);
return 0;
} else if (n >= 0){
if (lines[n].count > 0) {
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;
}
}
} else if(!all_allowed){
printk("line_setup - can't configure all devices from "
"mconsole\n");
return 0;
} 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;
}
}
}
}
return 1;
}
int line_config(struct line *lines, unsigned int num, char *str)
{
char *new = uml_strdup(str);
if(new == NULL){
printk("line_config - uml_strdup failed\n");
return -ENOMEM;
}
return !line_setup(lines, num, new, 0);
}
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->lock);
if(!line->valid)
CONFIG_CHUNK(str, size, n, "none", 1);
else if(line->count == 0)
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);
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 config[sizeof("conxxxx=none\0")];
sprintf(config, "%d=none", n);
return !line_setup(lines, num, config, 0);
}
struct tty_driver *line_register_devfs(struct lines *set,
struct line_driver *line_driver,
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->devfs_name = line_driver->devfs_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("%s: can't register %s driver\n",
__FUNCTION__,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 spinlock_t winch_handler_lock;
LIST_HEAD(winch_handlers);
void lines_init(struct line *lines, int nlines)
{
struct line *line;
int i;
spin_lock_init(&winch_handler_lock);
for(i = 0; i < nlines; i++){
line = &lines[i];
INIT_LIST_HEAD(&line->chan_list);
spin_lock_init(&line->lock);
if(line->init_str != NULL){
line->init_str = uml_strdup(line->init_str);
if(line->init_str == NULL)
printk("lines_init - uml_strdup returned "
"NULL\n");
}
}
}
struct winch {
struct list_head list;
int fd;
int tty_fd;
int pid;
struct tty_struct *tty;
};
irqreturn_t winch_interrupt(int irq, void *data, struct pt_regs *unused)
{
struct winch *winch = data;
struct tty_struct *tty;
struct line *line;
int err;
char c;
if(winch->fd != -1){
err = generic_read(winch->fd, &c, NULL);
if(err < 0){
if(err != -EAGAIN){
printk("winch_interrupt : read failed, "
"errno = %d\n", -err);
printk("fd %d is losing SIGWINCH support\n",
winch->tty_fd);
return IRQ_HANDLED;
}
goto out;
}
}
tty = winch->tty;
if (tty != NULL) {
line = tty->driver_data;
chan_window_size(&line->chan_list,
&tty->winsize.ws_row,
&tty->winsize.ws_col);
kill_pg(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)
{
struct winch *winch;
winch = kmalloc(sizeof(*winch), GFP_KERNEL);
if (winch == NULL) {
printk("register_winch_irq - kmalloc failed\n");
return;
}
*winch = ((struct winch) { .list = LIST_HEAD_INIT(winch->list),
.fd = fd,
.tty_fd = tty_fd,
.pid = pid,
.tty = tty });
spin_lock(&winch_handler_lock);
list_add(&winch->list, &winch_handlers);
spin_unlock(&winch_handler_lock);
if(um_request_irq(WINCH_IRQ, fd, IRQ_READ, winch_interrupt,
SA_INTERRUPT | SA_SHIRQ | SA_SAMPLE_RANDOM,
"winch", winch) < 0)
printk("register_winch_irq - failed to register IRQ\n");
}
static void unregister_winch(struct tty_struct *tty)
{
struct list_head *ele;
struct winch *winch, *found = NULL;
spin_lock(&winch_handler_lock);
list_for_each(ele, &winch_handlers){
winch = list_entry(ele, struct winch, list);
if(winch->tty == tty){
found = winch;
break;
}
}
if(found == NULL)
goto err;
list_del(&winch->list);
spin_unlock(&winch_handler_lock);
if(winch->pid != -1)
os_kill_process(winch->pid, 1);
free_irq(WINCH_IRQ, winch);
kfree(winch);
return;
err:
spin_unlock(&winch_handler_lock);
}
/* XXX: No lock as it's an exitcall... is this valid? Depending on cleanup
* order... are we sure that nothing else is done on the list? */
static void winch_cleanup(void)
{
struct list_head *ele;
struct winch *winch;
list_for_each(ele, &winch_handlers){
winch = list_entry(ele, struct winch, list);
if(winch->fd != -1){
/* Why is this different from the above free_irq(),
* which deactivates SIGIO? This searches the FD
* somewhere else and removes it from the list... */
deactivate_fd(winch->fd, WINCH_IRQ);
os_close_file(winch->fd);
}
if(winch->pid != -1)
os_kill_process(winch->pid, 1);
}
}
__uml_exitcall(winch_cleanup);
char *add_xterm_umid(char *base)
{
char *umid, *title;
int len;
umid = get_umid(1);
if(umid == NULL)
return base;
len = strlen(base) + strlen(" ()") + strlen(umid) + 1;
title = kmalloc(len, GFP_KERNEL);
if(title == NULL){
printk("Failed to allocate buffer for xterm title\n");
return base;
}
snprintf(title, len, "%s (%s)", base, umid);
return title;
}