android_kernel_xiaomi_sm8350/arch/um/drivers/line.c

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[PATCH] uml: Simplify console opening/closing and irq registration This patch simplifies the opening and closing of host console devices and the registration and deregistration of IRQs. The intent is to make it obvious that an IRQ can't exist without an open file descriptor. chan_enable will now open the channel, and when both opening and IRQ registration are desired, this should be used. Opening only is done for the initial console, so that interface still needs to exist. The free_irqs_later interface is now gone. It was intended to avoid freeing an IRQ while it was being processed. It did this, but it didn't eliminate the possiblity of free_irq being called from an interrupt, which is bad. In its place is a list of irqs to be freed, which is processed by the signal handler just before exiting. close_one_chan now disables irqs. When a host device disappears, it is just closed, and that disables IRQs. The device id registered with the IRQ is now the chan structure, not the tty. This is because the interrupt arrives on a descriptor associated with the channel. This caused equivalent changes in the arguments to line_timer_cb. line_disable is gone since it is not used any more. The count field in the line structure is gone. tty->count is used instead. The complicated logic in sigio_handler with freeing IRQs when necessary and making sure its idea of the next irq is correct is now much simpler. The irq list can't be rearranged underneath it, so it is now a simple list walk. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 03:18:57 -05:00
/*
* Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Licensed under the GPL
*/
#include "linux/irqreturn.h"
#include "linux/kd.h"
#include "chan_kern.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)
{
[PATCH] uml: Simplify console opening/closing and irq registration This patch simplifies the opening and closing of host console devices and the registration and deregistration of IRQs. The intent is to make it obvious that an IRQ can't exist without an open file descriptor. chan_enable will now open the channel, and when both opening and IRQ registration are desired, this should be used. Opening only is done for the initial console, so that interface still needs to exist. The free_irqs_later interface is now gone. It was intended to avoid freeing an IRQ while it was being processed. It did this, but it didn't eliminate the possiblity of free_irq being called from an interrupt, which is bad. In its place is a list of irqs to be freed, which is processed by the signal handler just before exiting. close_one_chan now disables irqs. When a host device disappears, it is just closed, and that disables IRQs. The device id registered with the IRQ is now the chan structure, not the tty. This is because the interrupt arrives on a descriptor associated with the channel. This caused equivalent changes in the arguments to line_timer_cb. line_disable is gone since it is not used any more. The count field in the line structure is gone. tty->count is used instead. The complicated logic in sigio_handler with freeing IRQs when necessary and making sure its idea of the next irq is correct is now much simpler. The irq list can't be rearranged underneath it, so it is now a simple list walk. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 03:18:57 -05:00
struct chan *chan = data;
struct line *line = chan->line;
struct tty_struct *tty = line->tty;
if (line)
chan_interrupt(&line->chan_list, &line->task, 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;
int err;
spin_lock_irqsave(&line->lock, flags);
err = 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, 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)) {
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)
{
[PATCH] uml: Simplify console opening/closing and irq registration This patch simplifies the opening and closing of host console devices and the registration and deregistration of IRQs. The intent is to make it obvious that an IRQ can't exist without an open file descriptor. chan_enable will now open the channel, and when both opening and IRQ registration are desired, this should be used. Opening only is done for the initial console, so that interface still needs to exist. The free_irqs_later interface is now gone. It was intended to avoid freeing an IRQ while it was being processed. It did this, but it didn't eliminate the possiblity of free_irq being called from an interrupt, which is bad. In its place is a list of irqs to be freed, which is processed by the signal handler just before exiting. close_one_chan now disables irqs. When a host device disappears, it is just closed, and that disables IRQs. The device id registered with the IRQ is now the chan structure, not the tty. This is because the interrupt arrives on a descriptor associated with the channel. This caused equivalent changes in the arguments to line_timer_cb. line_disable is gone since it is not used any more. The count field in the line structure is gone. tty->count is used instead. The complicated logic in sigio_handler with freeing IRQs when necessary and making sure its idea of the next irq is correct is now much simpler. The irq list can't be rearranged underneath it, so it is now a simple list walk. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 03:18:57 -05:00
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;
}
[PATCH] uml: Simplify console opening/closing and irq registration This patch simplifies the opening and closing of host console devices and the registration and deregistration of IRQs. The intent is to make it obvious that an IRQ can't exist without an open file descriptor. chan_enable will now open the channel, and when both opening and IRQ registration are desired, this should be used. Opening only is done for the initial console, so that interface still needs to exist. The free_irqs_later interface is now gone. It was intended to avoid freeing an IRQ while it was being processed. It did this, but it didn't eliminate the possiblity of free_irq being called from an interrupt, which is bad. In its place is a list of irqs to be freed, which is processed by the signal handler just before exiting. close_one_chan now disables irqs. When a host device disappears, it is just closed, and that disables IRQs. The device id registered with the IRQ is now the chan structure, not the tty. This is because the interrupt arrives on a descriptor associated with the channel. This caused equivalent changes in the arguments to line_timer_cb. line_disable is gone since it is not used any more. The count field in the line structure is gone. tty->count is used instead. The complicated logic in sigio_handler with freeing IRQs when necessary and making sure its idea of the next irq is correct is now much simpler. The irq list can't be rearranged underneath it, so it is now a simple list walk. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 03:18:57 -05:00
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,
[PATCH] uml: Simplify console opening/closing and irq registration This patch simplifies the opening and closing of host console devices and the registration and deregistration of IRQs. The intent is to make it obvious that an IRQ can't exist without an open file descriptor. chan_enable will now open the channel, and when both opening and IRQ registration are desired, this should be used. Opening only is done for the initial console, so that interface still needs to exist. The free_irqs_later interface is now gone. It was intended to avoid freeing an IRQ while it was being processed. It did this, but it didn't eliminate the possiblity of free_irq being called from an interrupt, which is bad. In its place is a list of irqs to be freed, which is processed by the signal handler just before exiting. close_one_chan now disables irqs. When a host device disappears, it is just closed, and that disables IRQs. The device id registered with the IRQ is now the chan structure, not the tty. This is because the interrupt arrives on a descriptor associated with the channel. This caused equivalent changes in the arguments to line_timer_cb. line_disable is gone since it is not used any more. The count field in the line structure is gone. tty->count is used instead. The complicated logic in sigio_handler with freeing IRQs when necessary and making sure its idea of the next irq is correct is now much simpler. The irq list can't be rearranged underneath it, so it is now a simple list walk. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 03:18:57 -05:00
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,
[PATCH] uml: Simplify console opening/closing and irq registration This patch simplifies the opening and closing of host console devices and the registration and deregistration of IRQs. The intent is to make it obvious that an IRQ can't exist without an open file descriptor. chan_enable will now open the channel, and when both opening and IRQ registration are desired, this should be used. Opening only is done for the initial console, so that interface still needs to exist. The free_irqs_later interface is now gone. It was intended to avoid freeing an IRQ while it was being processed. It did this, but it didn't eliminate the possiblity of free_irq being called from an interrupt, which is bad. In its place is a list of irqs to be freed, which is processed by the signal handler just before exiting. close_one_chan now disables irqs. When a host device disappears, it is just closed, and that disables IRQs. The device id registered with the IRQ is now the chan structure, not the tty. This is because the interrupt arrives on a descriptor associated with the channel. This caused equivalent changes in the arguments to line_timer_cb. line_disable is gone since it is not used any more. The count field in the line structure is gone. tty->count is used instead. The complicated logic in sigio_handler with freeing IRQs when necessary and making sure its idea of the next irq is correct is now much simpler. The irq list can't be rearranged underneath it, so it is now a simple list walk. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 03:18:57 -05:00
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.
*
* 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 = &lines[tty->index];
[PATCH] uml: Simplify console opening/closing and irq registration This patch simplifies the opening and closing of host console devices and the registration and deregistration of IRQs. The intent is to make it obvious that an IRQ can't exist without an open file descriptor. chan_enable will now open the channel, and when both opening and IRQ registration are desired, this should be used. Opening only is done for the initial console, so that interface still needs to exist. The free_irqs_later interface is now gone. It was intended to avoid freeing an IRQ while it was being processed. It did this, but it didn't eliminate the possiblity of free_irq being called from an interrupt, which is bad. In its place is a list of irqs to be freed, which is processed by the signal handler just before exiting. close_one_chan now disables irqs. When a host device disappears, it is just closed, and that disables IRQs. The device id registered with the IRQ is now the chan structure, not the tty. This is because the interrupt arrives on a descriptor associated with the channel. This caused equivalent changes in the arguments to line_timer_cb. line_disable is gone since it is not used any more. The count field in the line structure is gone. tty->count is used instead. The complicated logic in sigio_handler with freeing IRQs when necessary and making sure its idea of the next irq is correct is now much simpler. The irq list can't be rearranged underneath it, so it is now a simple list walk. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 03:18:57 -05:00
int err = -ENODEV;
spin_lock(&line->count_lock);
if (!line->valid)
goto out_unlock;
err = 0;
if (tty->count > 1)
goto out_unlock;
spin_unlock(&line->count_lock);
[PATCH] uml: Simplify console opening/closing and irq registration This patch simplifies the opening and closing of host console devices and the registration and deregistration of IRQs. The intent is to make it obvious that an IRQ can't exist without an open file descriptor. chan_enable will now open the channel, and when both opening and IRQ registration are desired, this should be used. Opening only is done for the initial console, so that interface still needs to exist. The free_irqs_later interface is now gone. It was intended to avoid freeing an IRQ while it was being processed. It did this, but it didn't eliminate the possiblity of free_irq being called from an interrupt, which is bad. In its place is a list of irqs to be freed, which is processed by the signal handler just before exiting. close_one_chan now disables irqs. When a host device disappears, it is just closed, and that disables IRQs. The device id registered with the IRQ is now the chan structure, not the tty. This is because the interrupt arrives on a descriptor associated with the channel. This caused equivalent changes in the arguments to line_timer_cb. line_disable is gone since it is not used any more. The count field in the line structure is gone. tty->count is used instead. The complicated logic in sigio_handler with freeing IRQs when necessary and making sure its idea of the next irq is correct is now much simpler. The irq list can't be rearranged underneath it, so it is now a simple list walk. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 03:18:57 -05:00
tty->driver_data = line;
line->tty = tty;
err = enable_chan(line);
if (err)
return err;
INIT_DELAYED_WORK(&line->task, line_timer_cb);
[PATCH] uml: Simplify console opening/closing and irq registration This patch simplifies the opening and closing of host console devices and the registration and deregistration of IRQs. The intent is to make it obvious that an IRQ can't exist without an open file descriptor. chan_enable will now open the channel, and when both opening and IRQ registration are desired, this should be used. Opening only is done for the initial console, so that interface still needs to exist. The free_irqs_later interface is now gone. It was intended to avoid freeing an IRQ while it was being processed. It did this, but it didn't eliminate the possiblity of free_irq being called from an interrupt, which is bad. In its place is a list of irqs to be freed, which is processed by the signal handler just before exiting. close_one_chan now disables irqs. When a host device disappears, it is just closed, and that disables IRQs. The device id registered with the IRQ is now the chan structure, not the tty. This is because the interrupt arrives on a descriptor associated with the channel. This caused equivalent changes in the arguments to line_timer_cb. line_disable is gone since it is not used any more. The count field in the line structure is gone. tty->count is used instead. The complicated logic in sigio_handler with freeing IRQs when necessary and making sure its idea of the next irq is correct is now much simpler. The irq list can't be rearranged underneath it, so it is now a simple list walk. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 03:18:57 -05:00
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 err;
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);
if (!line->valid)
goto out_unlock;
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;
}
return;
out_unlock:
spin_unlock(&line->count_lock);
}
void close_lines(struct line *lines, int nlines)
{
int i;
for(i = 0; i < nlines; i++)
[PATCH] uml: Simplify console opening/closing and irq registration This patch simplifies the opening and closing of host console devices and the registration and deregistration of IRQs. The intent is to make it obvious that an IRQ can't exist without an open file descriptor. chan_enable will now open the channel, and when both opening and IRQ registration are desired, this should be used. Opening only is done for the initial console, so that interface still needs to exist. The free_irqs_later interface is now gone. It was intended to avoid freeing an IRQ while it was being processed. It did this, but it didn't eliminate the possiblity of free_irq being called from an interrupt, which is bad. In its place is a list of irqs to be freed, which is processed by the signal handler just before exiting. close_one_chan now disables irqs. When a host device disappears, it is just closed, and that disables IRQs. The device id registered with the IRQ is now the chan structure, not the tty. This is because the interrupt arrives on a descriptor associated with the channel. This caused equivalent changes in the arguments to line_timer_cb. line_disable is gone since it is not used any more. The count field in the line structure is gone. tty->count is used instead. The complicated logic in sigio_handler with freeing IRQs when necessary and making sure its idea of the next irq is correct is now much simpler. The irq list can't be rearranged underneath it, so it is now a simple list walk. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 03:18:57 -05:00
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,
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;
};
static void free_winch(struct winch *winch, int free_irq_ok)
{
list_del(&winch->list);
if (winch->pid != -1)
os_kill_process(winch->pid, 1);
if (winch->fd != -1)
os_close_file(winch->fd);
if (winch->stack != 0)
free_stack(winch->stack, 0);
if (free_irq_ok)
free_irq(WINCH_IRQ, winch);
kfree(winch);
}
static irqreturn_t winch_interrupt(int irq, void *data)
{
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(KERN_ERR "winch_interrupt : "
"read failed, errno = %d\n", -err);
printk(KERN_ERR "fd %d is losing SIGWINCH "
"support\n", winch->tty_fd);
free_winch(winch, 0);
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;
struct winch *winch;
spin_lock(&winch_handler_lock);
list_for_each(ele, &winch_handlers) {
winch = list_entry(ele, struct winch, list);
if (winch->tty == tty) {
free_winch(winch, 1);
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, 1);
}
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;
[PATCH] uml: Simplify console opening/closing and irq registration This patch simplifies the opening and closing of host console devices and the registration and deregistration of IRQs. The intent is to make it obvious that an IRQ can't exist without an open file descriptor. chan_enable will now open the channel, and when both opening and IRQ registration are desired, this should be used. Opening only is done for the initial console, so that interface still needs to exist. The free_irqs_later interface is now gone. It was intended to avoid freeing an IRQ while it was being processed. It did this, but it didn't eliminate the possiblity of free_irq being called from an interrupt, which is bad. In its place is a list of irqs to be freed, which is processed by the signal handler just before exiting. close_one_chan now disables irqs. When a host device disappears, it is just closed, and that disables IRQs. The device id registered with the IRQ is now the chan structure, not the tty. This is because the interrupt arrives on a descriptor associated with the channel. This caused equivalent changes in the arguments to line_timer_cb. line_disable is gone since it is not used any more. The count field in the line structure is gone. tty->count is used instead. The complicated logic in sigio_handler with freeing IRQs when necessary and making sure its idea of the next irq is correct is now much simpler. The irq list can't be rearranged underneath it, so it is now a simple list walk. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 03:18:57 -05:00
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;
}