/*
* Copyright (C) 2000 Jeff Dike (jdike@karaya.com)
* Licensed under the GPL
*/
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <signal.h>
#include <string.h>
#include <sys/poll.h>
#include <sys/types.h>
#include <sys/time.h>
#include "user_util.h"
#include "kern_util.h"
#include "user.h"
#include "process.h"
#include "signal_user.h"
#include "sigio.h"
#include "irq_user.h"
#include "os.h"
struct irq_fd {
struct irq_fd *next;
void *id;
int fd;
int type;
int irq;
int pid;
int events;
int current_events;
int freed;
};
static struct irq_fd *active_fds = NULL;
static struct irq_fd **last_irq_ptr = &active_fds;
static struct pollfd *pollfds = NULL;
static int pollfds_num = 0;
static int pollfds_size = 0;
extern int io_count, intr_count;
void sigio_handler(int sig, union uml_pt_regs *regs)
{
struct irq_fd *irq_fd, *next;
int i, n;
if(smp_sigio_handler()) return;
while(1){
n = poll(pollfds, pollfds_num, 0);
if(n < 0){
if(errno == EINTR) continue;
printk("sigio_handler : poll returned %d, "
"errno = %d\n", n, errno);
break;
}
if(n == 0) break;
irq_fd = active_fds;
for(i = 0; i < pollfds_num; i++){
if(pollfds[i].revents != 0){
irq_fd->current_events = pollfds[i].revents;
pollfds[i].fd = -1;
}
irq_fd = irq_fd->next;
}
for(irq_fd = active_fds; irq_fd != NULL; irq_fd = next){
next = irq_fd->next;
if(irq_fd->current_events != 0){
irq_fd->current_events = 0;
do_IRQ(irq_fd->irq, regs);
/* This is here because the next irq may be
* freed in the handler. If a console goes
* away, both the read and write irqs will be
* freed. After do_IRQ, ->next will point to
* a good IRQ.
* Irqs can't be freed inside their handlers,
* so the next best thing is to have them
* marked as needing freeing, so that they
* can be freed here.
*/
next = irq_fd->next;
if(irq_fd->freed){
free_irq(irq_fd->irq, irq_fd->id);
free_irq_by_irq_and_dev(irq_fd->irq,
irq_fd->id);
}
}
}
}
}
int activate_ipi(int fd, int pid)
{
return(os_set_fd_async(fd, pid));
}
static void maybe_sigio_broken(int fd, int type)
{
if(isatty(fd)){
if((type == IRQ_WRITE) && !pty_output_sigio){
write_sigio_workaround();
add_sigio_fd(fd, 0);
}
else if((type == IRQ_READ) && !pty_close_sigio){
write_sigio_workaround();
add_sigio_fd(fd, 1);
}
}
}
int activate_fd(int irq, int fd, int type, void *dev_id)
{
struct pollfd *tmp_pfd;
struct irq_fd *new_fd, *irq_fd;
unsigned long flags;
int pid, events, err, n, size;
pid = os_getpid();
err = os_set_fd_async(fd, pid);
if(err < 0)
goto out;
new_fd = um_kmalloc(sizeof(*new_fd));
err = -ENOMEM;
if(new_fd == NULL)
goto out;
if(type == IRQ_READ) events = POLLIN | POLLPRI;
else events = POLLOUT;
*new_fd = ((struct irq_fd) { .next = NULL,
.id = dev_id,
.fd = fd,
.type = type,
.irq = irq,
.pid = pid,
.events = events,
.current_events = 0,
.freed = 0 } );
/* Critical section - locked by a spinlock because this stuff can
* be changed from interrupt handlers. The stuff above is done
* outside the lock because it allocates memory.
*/
/* Actually, it only looks like it can be called from interrupt
* context. The culprit is reactivate_fd, which calls
* maybe_sigio_broken, which calls write_sigio_workaround,
* which calls activate_fd. However, write_sigio_workaround should
* only be called once, at boot time. That would make it clear that
* this is called only from process context, and can be locked with
* a semaphore.
*/
flags = irq_lock();
for(irq_fd = active_fds; irq_fd != NULL; irq_fd = irq_fd->next){
if((irq_fd->fd == fd) && (irq_fd->type == type)){
printk("Registering fd %d twice\n", fd);
printk("Irqs : %d, %d\n", irq_fd->irq, irq);
printk("Ids : 0x%x, 0x%x\n", irq_fd->id, dev_id);
goto out_unlock;
}
}
n = pollfds_num;
if(n == pollfds_size){
while(1){
/* Here we have to drop the lock in order to call
* kmalloc, which might sleep. If something else
* came in and changed the pollfds array, we free
* the buffer and try again.
*/
irq_unlock(flags);
size = (pollfds_num + 1) * sizeof(pollfds[0]);
tmp_pfd = um_kmalloc(size);
flags = irq_lock();
if(tmp_pfd == NULL)
goto out_unlock;
if(n == pollfds_size)
break;
kfree(tmp_pfd);
}
if(pollfds != NULL){
memcpy(tmp_pfd, pollfds,
sizeof(pollfds[0]) * pollfds_size);
kfree(pollfds);
}
pollfds = tmp_pfd;
pollfds_size++;
}
if(type == IRQ_WRITE)
fd = -1;
pollfds[pollfds_num] = ((struct pollfd) { .fd = fd,
.events = events,
.revents = 0 });
pollfds_num++;
*last_irq_ptr = new_fd;
last_irq_ptr = &new_fd->next;
irq_unlock(flags);
/* This calls activate_fd, so it has to be outside the critical
* section.
*/
maybe_sigio_broken(fd, type);
return(0);
out_unlock:
irq_unlock(flags);
kfree(new_fd);
out:
return(err);
}
static void free_irq_by_cb(int (*test)(struct irq_fd *, void *), void *arg)
{
struct irq_fd **prev;
unsigned long flags;
int i = 0;
flags = irq_lock();
prev = &active_fds;
while(*prev != NULL){
if((*test)(*prev, arg)){
struct irq_fd *old_fd = *prev;
if((pollfds[i].fd != -1) &&
(pollfds[i].fd != (*prev)->fd)){
printk("free_irq_by_cb - mismatch between "
"active_fds and pollfds, fd %d vs %d\n",
(*prev)->fd, pollfds[i].fd);
goto out;
}
pollfds_num--;
/* This moves the *whole* array after pollfds[i] (though
* it doesn't spot as such)! */
memmove(&pollfds[i], &pollfds[i + 1],
(pollfds_num - i) * sizeof(pollfds[0]));
if(last_irq_ptr == &old_fd->next)
last_irq_ptr = prev;
*prev = (*prev)->next;
if(old_fd->type == IRQ_WRITE)
ignore_sigio_fd(old_fd->fd);
kfree(old_fd);
continue;
}
prev = &(*prev)->next;
i++;
}
out:
irq_unlock(flags);
}
struct irq_and_dev {
int irq;
void *dev;
};
static int same_irq_and_dev(struct irq_fd *irq, void *d)
{
struct irq_and_dev *data = d;
return((irq->irq == data->irq) && (irq->id == data->dev));
}
void free_irq_by_irq_and_dev(unsigned int irq, void *dev)
{
struct irq_and_dev data = ((struct irq_and_dev) { .irq = irq,
.dev = dev });
free_irq_by_cb(same_irq_and_dev, &data);
}
static int same_fd(struct irq_fd *irq, void *fd)
{
return(irq->fd == *((int *) fd));
}
void free_irq_by_fd(int fd)
{
free_irq_by_cb(same_fd, &fd);
}
static struct irq_fd *find_irq_by_fd(int fd, int irqnum, int *index_out)
{
struct irq_fd *irq;
int i = 0;
for(irq=active_fds; irq != NULL; irq = irq->next){
if((irq->fd == fd) && (irq->irq == irqnum)) break;
i++;
}
if(irq == NULL){
printk("find_irq_by_fd doesn't have descriptor %d\n", fd);
goto out;
}
if((pollfds[i].fd != -1) && (pollfds[i].fd != fd)){
printk("find_irq_by_fd - mismatch between active_fds and "
"pollfds, fd %d vs %d, need %d\n", irq->fd,
pollfds[i].fd, fd);
irq = NULL;
goto out;
}
*index_out = i;
out:
return(irq);
}
void free_irq_later(int irq, void *dev_id)
{
struct irq_fd *irq_fd;
unsigned long flags;
flags = irq_lock();
for(irq_fd = active_fds; irq_fd != NULL; irq_fd = irq_fd->next){
if((irq_fd->irq == irq) && (irq_fd->id == dev_id))
break;
}
if(irq_fd == NULL){
printk("free_irq_later found no irq, irq = %d, "
"dev_id = 0x%p\n", irq, dev_id);
goto out;
}
irq_fd->freed = 1;
out:
irq_unlock(flags);
}
void reactivate_fd(int fd, int irqnum)
{
struct irq_fd *irq;
unsigned long flags;
int i;
flags = irq_lock();
irq = find_irq_by_fd(fd, irqnum, &i);
if(irq == NULL){
irq_unlock(flags);
return;
}
pollfds[i].fd = irq->fd;
irq_unlock(flags);
/* This calls activate_fd, so it has to be outside the critical
* section.
*/
maybe_sigio_broken(fd, irq->type);
}
void deactivate_fd(int fd, int irqnum)
{
struct irq_fd *irq;
unsigned long flags;
int i;
flags = irq_lock();
irq = find_irq_by_fd(fd, irqnum, &i);
if(irq == NULL)
goto out;
pollfds[i].fd = -1;
out:
irq_unlock(flags);
}
int deactivate_all_fds(void)
{
struct irq_fd *irq;
int err;
for(irq=active_fds;irq != NULL;irq = irq->next){
err = os_clear_fd_async(irq->fd);
if(err)
return(err);
}
/* If there is a signal already queued, after unblocking ignore it */
set_handler(SIGIO, SIG_IGN, 0, -1);
return(0);
}
void forward_ipi(int fd, int pid)
{
int err;
err = os_set_owner(fd, pid);
if(err < 0)
printk("forward_ipi: set_owner failed, fd = %d, me = %d, "
"target = %d, err = %d\n", fd, os_getpid(), pid, -err);
}
void forward_interrupts(int pid)
{
struct irq_fd *irq;
unsigned long flags;
int err;
flags = irq_lock();
for(irq=active_fds;irq != NULL;irq = irq->next){
err = os_set_owner(irq->fd, pid);
if(err < 0){
/* XXX Just remove the irq rather than
* print out an infinite stream of these
*/
printk("Failed to forward %d to pid %d, err = %d\n",
irq->fd, pid, -err);
}
irq->pid = pid;
}
irq_unlock(flags);
}
void init_irq_signals(int on_sigstack)
{
__sighandler_t h;
int flags;
flags = on_sigstack ? SA_ONSTACK : 0;
if(timer_irq_inited) h = (__sighandler_t) alarm_handler;
else h = boot_timer_handler;
set_handler(SIGVTALRM, h, flags | SA_RESTART,
SIGUSR1, SIGIO, SIGWINCH, SIGALRM, -1);
set_handler(SIGIO, (__sighandler_t) sig_handler, flags | SA_RESTART,
SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
signal(SIGWINCH, SIG_IGN);
}
/*
* Overrides for Emacs so that we follow Linus's tabbing style.
* Emacs will notice this stuff at the end of the file and automatically
* adjust the settings for this buffer only. This must remain at the end
* of the file.
* ---------------------------------------------------------------------------
* Local variables:
* c-file-style: "linux"
* End:
*/
