[linux-block.git] / arch / um / kernel / irq.c

/* 
 * Copyright (C) 2000 Jeff Dike (jdike@karaya.com)
 * Licensed under the GPL
 * Derived (i.e. mostly copied) from arch/i386/kernel/irq.c:
 *	Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
 */

#include "linux/config.h"
#include "linux/kernel.h"
#include "linux/module.h"
#include "linux/smp.h"
#include "linux/kernel_stat.h"
#include "linux/interrupt.h"
#include "linux/random.h"
#include "linux/slab.h"
#include "linux/file.h"
#include "linux/proc_fs.h"
#include "linux/init.h"
#include "linux/seq_file.h"
#include "linux/profile.h"
#include "linux/hardirq.h"
#include "asm/irq.h"
#include "asm/hw_irq.h"
#include "asm/atomic.h"
#include "asm/signal.h"
#include "asm/system.h"
#include "asm/errno.h"
#include "asm/uaccess.h"
#include "user_util.h"
#include "kern_util.h"
#include "irq_user.h"
#include "irq_kern.h"
#include "os.h"
#include "sigio.h"
#include "misc_constants.h"

/*
 * Generic, controller-independent functions:
 */

int show_interrupts(struct seq_file *p, void *v)
{
	int i = *(loff_t *) v, j;
	struct irqaction * action;
	unsigned long flags;

	if (i == 0) {
		seq_printf(p, "           ");
		for_each_online_cpu(j)
			seq_printf(p, "CPU%d       ",j);
		seq_putc(p, '\n');
	}

	if (i < NR_IRQS) {
		spin_lock_irqsave(&irq_desc[i].lock, flags);
		action = irq_desc[i].action;
		if (!action) 
			goto skip;
		seq_printf(p, "%3d: ",i);
#ifndef CONFIG_SMP
		seq_printf(p, "%10u ", kstat_irqs(i));
#else
		for_each_online_cpu(j)
			seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
#endif
		seq_printf(p, " %14s", irq_desc[i].handler->typename);
		seq_printf(p, "  %s", action->name);

		for (action=action->next; action; action = action->next)
			seq_printf(p, ", %s", action->name);

		seq_putc(p, '\n');
skip:
		spin_unlock_irqrestore(&irq_desc[i].lock, flags);
	} else if (i == NR_IRQS) {
		seq_putc(p, '\n');
	}

	return 0;
}

struct irq_fd *active_fds = NULL;
static struct irq_fd **last_irq_ptr = &active_fds;

extern void free_irqs(void);

void sigio_handler(int sig, union uml_pt_regs *regs)
{
	struct irq_fd *irq_fd;
	int n;

	if (smp_sigio_handler())
		return;

	while (1) {
		n = os_waiting_for_events(active_fds);
		if (n <= 0) {
			if(n == -EINTR) continue;
			else break;
		}

		for (irq_fd = active_fds; irq_fd != NULL; irq_fd = irq_fd->next) {
			if (irq_fd->current_events != 0) {
				irq_fd->current_events = 0;
				do_IRQ(irq_fd->irq, regs);
			}
		}
	}

	free_irqs();
}

static void maybe_sigio_broken(int fd, int type)
{
	if (os_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;

	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 = UM_POLLIN | UM_POLLPRI;
	else
		events = UM_POLLOUT;
	*new_fd = ((struct irq_fd) { .next  		= NULL,
				     .id 		= dev_id,
				     .fd 		= fd,
				     .type 		= type,
				     .irq 		= irq,
				     .pid  		= pid,
				     .events 		= events,
				     .current_events 	= 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%p, 0x%p\n", irq_fd->id, dev_id);
			goto out_unlock;
		}
	}

	/*-------------*/
	if (type == IRQ_WRITE)
		fd = -1;

	tmp_pfd = NULL;
	n = 0;

	while (1) {
		n = os_create_pollfd(fd, events, tmp_pfd, n);
		if (n == 0)
			break;

		/* n > 0
		 * It means we couldn't put new pollfd to current pollfds
		 * and tmp_fds is NULL or too small for new pollfds array.
		 * Needed size is equal to n as minimum.
		 *
		 * 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
		 * so we will not be able to put new pollfd struct to pollfds
		 * then we free the buffer tmp_fds and try again.
		 */
		irq_unlock(flags);
		kfree(tmp_pfd);
		tmp_pfd = NULL;

		tmp_pfd = um_kmalloc(n);
		if (tmp_pfd == NULL)
			goto out_kfree;

		flags = irq_lock();
	}
	/*-------------*/

	*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);
 out_kfree:
	kfree(new_fd);
 out:
	return(err);
}

static void free_irq_by_cb(int (*test)(struct irq_fd *, void *), void *arg)
{
	unsigned long flags;

	flags = irq_lock();
	os_free_irq_by_cb(test, arg, active_fds, &last_irq_ptr);
	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;
	int fdi;

	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;
	}
	fdi = os_get_pollfd(i);
	if ((fdi != -1) && (fdi != fd)) {
		printk("find_irq_by_fd - mismatch between active_fds and "
		       "pollfds, fd %d vs %d, need %d\n", irq->fd,
		       fdi, fd);
		irq = NULL;
		goto out;
	}
	*index_out = i;
 out:
	return irq;
}

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;
	}
	os_set_pollfd(i, 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;
	os_set_pollfd(i, -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 */
	os_set_ioignore();

	return 0;
}

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);
}

/*
 * do_IRQ handles all normal device IRQ's (the special
 * SMP cross-CPU interrupts have their own specific
 * handlers).
 */
unsigned int do_IRQ(int irq, union uml_pt_regs *regs)
{
       irq_enter();
       __do_IRQ(irq, (struct pt_regs *)regs);
       irq_exit();
       return 1;
}

int um_request_irq(unsigned int irq, int fd, int type,
		   irqreturn_t (*handler)(int, void *, struct pt_regs *),
		   unsigned long irqflags, const char * devname,
		   void *dev_id)
{
	int err;

	err = request_irq(irq, handler, irqflags, devname, dev_id);
	if (err)
		return err;

	if (fd != -1)
		err = activate_fd(irq, fd, type, dev_id);
	return err;
}
EXPORT_SYMBOL(um_request_irq);
EXPORT_SYMBOL(reactivate_fd);

static DEFINE_SPINLOCK(irq_spinlock);

unsigned long irq_lock(void)
{
	unsigned long flags;

	spin_lock_irqsave(&irq_spinlock, flags);
	return flags;
}

void irq_unlock(unsigned long flags)
{
	spin_unlock_irqrestore(&irq_spinlock, flags);
}

/* hw_interrupt_type must define (startup || enable) &&
 * (shutdown || disable) && end */
static void dummy(unsigned int irq)
{
}

/* This is used for everything else than the timer. */
static struct hw_interrupt_type normal_irq_type = {
	.typename = "SIGIO",
	.release = free_irq_by_irq_and_dev,
	.disable = dummy,
	.enable = dummy,
	.ack = dummy,
	.end = dummy
};

static struct hw_interrupt_type SIGVTALRM_irq_type = {
	.typename = "SIGVTALRM",
	.release = free_irq_by_irq_and_dev,
	.shutdown = dummy, /* never called */
	.disable = dummy,
	.enable = dummy,
	.ack = dummy,
	.end = dummy
};

void __init init_IRQ(void)
{
	int i;

	irq_desc[TIMER_IRQ].status = IRQ_DISABLED;
	irq_desc[TIMER_IRQ].action = NULL;
	irq_desc[TIMER_IRQ].depth = 1;
	irq_desc[TIMER_IRQ].handler = &SIGVTALRM_irq_type;
	enable_irq(TIMER_IRQ);
	for (i = 1; i < NR_IRQS; i++) {
		irq_desc[i].status = IRQ_DISABLED;
		irq_desc[i].action = NULL;
		irq_desc[i].depth = 1;
		irq_desc[i].handler = &normal_irq_type;
		enable_irq(i);
	}
}

int init_aio_irq(int irq, char *name, irqreturn_t (*handler)(int, void *,
							     struct pt_regs *))
{
	int fds[2], err;

	err = os_pipe(fds, 1, 1);
	if (err) {
		printk("init_aio_irq - os_pipe failed, err = %d\n", -err);
		goto out;
	}

	err = um_request_irq(irq, fds[0], IRQ_READ, handler,
			     SA_INTERRUPT | SA_SAMPLE_RANDOM, name,
			     (void *) (long) fds[0]);
	if (err) {
		printk("init_aio_irq - : um_request_irq failed, err = %d\n",
		       err);
		goto out_close;
	}

	err = fds[1];
	goto out;

 out_close:
	os_close_file(fds[0]);
	os_close_file(fds[1]);
 out:
	return err;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Copyright (C) 2000 Jeff Dike (jdike@karaya.com)
	3	* Licensed under the GPL
	4	* Derived (i.e. mostly copied) from arch/i386/kernel/irq.c:
	5	* Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
	6	*/
	7
	8	#include "linux/config.h"
	9	#include "linux/kernel.h"
	10	#include "linux/module.h"
	11	#include "linux/smp.h"
1da177e4 LT	12	#include "linux/kernel_stat.h"
	13	#include "linux/interrupt.h"
	14	#include "linux/random.h"
	15	#include "linux/slab.h"
	16	#include "linux/file.h"
	17	#include "linux/proc_fs.h"
	18	#include "linux/init.h"
	19	#include "linux/seq_file.h"
	20	#include "linux/profile.h"
	21	#include "linux/hardirq.h"
	22	#include "asm/irq.h"
	23	#include "asm/hw_irq.h"
	24	#include "asm/atomic.h"
	25	#include "asm/signal.h"
	26	#include "asm/system.h"
	27	#include "asm/errno.h"
	28	#include "asm/uaccess.h"
	29	#include "user_util.h"
	30	#include "kern_util.h"
	31	#include "irq_user.h"
	32	#include "irq_kern.h"
75e5584c	33	#include "os.h"
9b4f018d JD	34	#include "sigio.h"
9b4f018d JD	35	#include "misc_constants.h"
1da177e4 LT	36
	37	/*
	38	* Generic, controller-independent functions:
	39	*/
	40
	41	int show_interrupts(struct seq_file p, void v)
	42	{
	43	int i = (loff_t ) v, j;
	44	struct irqaction * action;
	45	unsigned long flags;
	46
	47	if (i == 0) {
	48	seq_printf(p, " ");
	49	for_each_online_cpu(j)
	50	seq_printf(p, "CPU%d ",j);
	51	seq_putc(p, '\n');
	52	}
	53
	54	if (i < NR_IRQS) {
	55	spin_lock_irqsave(&irq_desc[i].lock, flags);
	56	action = irq_desc[i].action;
	57	if (!action)
	58	goto skip;
	59	seq_printf(p, "%3d: ",i);
	60	#ifndef CONFIG_SMP
	61	seq_printf(p, "%10u ", kstat_irqs(i));
	62	#else
	63	for_each_online_cpu(j)
	64	seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
	65	#endif
	66	seq_printf(p, " %14s", irq_desc[i].handler->typename);
	67	seq_printf(p, " %s", action->name);
	68
	69	for (action=action->next; action; action = action->next)
	70	seq_printf(p, ", %s", action->name);
	71
	72	seq_putc(p, '\n');
	73	skip:
	74	spin_unlock_irqrestore(&irq_desc[i].lock, flags);
	75	} else if (i == NR_IRQS) {
	76	seq_putc(p, '\n');
	77	}
	78
	79	return 0;
	80	}
	81
9b4f018d JD	82	struct irq_fd *active_fds = NULL;
	83	static struct irq_fd **last_irq_ptr = &active_fds;
	84
	85	extern void free_irqs(void);
	86
	87	void sigio_handler(int sig, union uml_pt_regs *regs)
	88	{
	89	struct irq_fd *irq_fd;
	90	int n;
	91
191ef966 JJ	92	if (smp_sigio_handler())
	93	return;
	94
	95	while (1) {
9b4f018d JD	96	n = os_waiting_for_events(active_fds);
	97	if (n <= 0) {
	98	if(n == -EINTR) continue;
	99	else break;
	100	}
	101
191ef966 JJ	102	for (irq_fd = active_fds; irq_fd != NULL; irq_fd = irq_fd->next) {
191ef966 JJ	103	if (irq_fd->current_events != 0) {
9b4f018d JD	104	irq_fd->current_events = 0;
	105	do_IRQ(irq_fd->irq, regs);
	106	}
	107	}
	108	}
	109
	110	free_irqs();
	111	}
	112
	113	static void maybe_sigio_broken(int fd, int type)
	114	{
191ef966 JJ	115	if (os_isatty(fd)) {
191ef966 JJ	116	if ((type == IRQ_WRITE) && !pty_output_sigio) {
9b4f018d JD	117	write_sigio_workaround();
9b4f018d JD	118	add_sigio_fd(fd, 0);
191ef966	119	} else if ((type == IRQ_READ) && !pty_close_sigio) {
9b4f018d JD	120	write_sigio_workaround();
	121	add_sigio_fd(fd, 1);
	122	}
	123	}
	124	}
	125
9b4f018d JD	126	int activate_fd(int irq, int fd, int type, void *dev_id)
	127	{
	128	struct pollfd *tmp_pfd;
	129	struct irq_fd new_fd, irq_fd;
	130	unsigned long flags;
	131	int pid, events, err, n;
	132
	133	pid = os_getpid();
	134	err = os_set_fd_async(fd, pid);
191ef966	135	if (err < 0)
9b4f018d JD	136	goto out;
	137
	138	new_fd = um_kmalloc(sizeof(*new_fd));
	139	err = -ENOMEM;
191ef966	140	if (new_fd == NULL)
9b4f018d JD	141	goto out;
9b4f018d JD	142
191ef966 JJ	143	if (type == IRQ_READ)
	144	events = UM_POLLIN \| UM_POLLPRI;
	145	else
	146	events = UM_POLLOUT;
9b4f018d JD	147	*new_fd = ((struct irq_fd) { .next = NULL,
	148	.id = dev_id,
	149	.fd = fd,
	150	.type = type,
	151	.irq = irq,
	152	.pid = pid,
	153	.events = events,
	154	.current_events = 0 } );
	155
	156	/* Critical section - locked by a spinlock because this stuff can
	157	* be changed from interrupt handlers. The stuff above is done
	158	* outside the lock because it allocates memory.
	159	*/
	160
	161	/* Actually, it only looks like it can be called from interrupt
	162	* context. The culprit is reactivate_fd, which calls
	163	* maybe_sigio_broken, which calls write_sigio_workaround,
	164	* which calls activate_fd. However, write_sigio_workaround should
	165	* only be called once, at boot time. That would make it clear that
	166	* this is called only from process context, and can be locked with
	167	* a semaphore.
	168	*/
	169	flags = irq_lock();
191ef966 JJ	170	for (irq_fd = active_fds; irq_fd != NULL; irq_fd = irq_fd->next) {
191ef966 JJ	171	if ((irq_fd->fd == fd) && (irq_fd->type == type)) {
9b4f018d JD	172	printk("Registering fd %d twice\n", fd);
	173	printk("Irqs : %d, %d\n", irq_fd->irq, irq);
	174	printk("Ids : 0x%p, 0x%p\n", irq_fd->id, dev_id);
	175	goto out_unlock;
	176	}
	177	}
	178
	179	/-------------/
191ef966	180	if (type == IRQ_WRITE)
9b4f018d JD	181	fd = -1;
	182
	183	tmp_pfd = NULL;
	184	n = 0;
	185
191ef966	186	while (1) {
9b4f018d JD	187	n = os_create_pollfd(fd, events, tmp_pfd, n);
	188	if (n == 0)
	189	break;
	190
	191	/* n > 0
	192	* It means we couldn't put new pollfd to current pollfds
	193	* and tmp_fds is NULL or too small for new pollfds array.
	194	* Needed size is equal to n as minimum.
	195	*
	196	* Here we have to drop the lock in order to call
	197	* kmalloc, which might sleep.
	198	* If something else came in and changed the pollfds array
	199	* so we will not be able to put new pollfd struct to pollfds
	200	* then we free the buffer tmp_fds and try again.
	201	*/
	202	irq_unlock(flags);
191ef966 JJ	203	kfree(tmp_pfd);
191ef966 JJ	204	tmp_pfd = NULL;
9b4f018d JD	205
	206	tmp_pfd = um_kmalloc(n);
	207	if (tmp_pfd == NULL)
	208	goto out_kfree;
	209
	210	flags = irq_lock();
	211	}
	212	/-------------/
	213
	214	*last_irq_ptr = new_fd;
	215	last_irq_ptr = &new_fd->next;
	216
	217	irq_unlock(flags);
	218
	219	/* This calls activate_fd, so it has to be outside the critical
	220	* section.
	221	*/
	222	maybe_sigio_broken(fd, type);
	223
	224	return(0);
	225
	226	out_unlock:
	227	irq_unlock(flags);
	228	out_kfree:
	229	kfree(new_fd);
	230	out:
	231	return(err);
	232	}
	233
	234	static void free_irq_by_cb(int (test)(struct irq_fd , void ), void arg)
	235	{
	236	unsigned long flags;
	237
	238	flags = irq_lock();
	239	os_free_irq_by_cb(test, arg, active_fds, &last_irq_ptr);
	240	irq_unlock(flags);
	241	}
	242
	243	struct irq_and_dev {
	244	int irq;
	245	void *dev;
	246	};
	247
	248	static int same_irq_and_dev(struct irq_fd irq, void d)
	249	{
	250	struct irq_and_dev *data = d;
	251
191ef966	252	return ((irq->irq == data->irq) && (irq->id == data->dev));
9b4f018d JD	253	}
	254
	255	void free_irq_by_irq_and_dev(unsigned int irq, void *dev)
	256	{
	257	struct irq_and_dev data = ((struct irq_and_dev) { .irq = irq,
	258	.dev = dev });
	259
	260	free_irq_by_cb(same_irq_and_dev, &data);
	261	}
	262
	263	static int same_fd(struct irq_fd irq, void fd)
	264	{
191ef966	265	return (irq->fd == ((int )fd));
9b4f018d JD	266	}
	267
	268	void free_irq_by_fd(int fd)
	269	{
	270	free_irq_by_cb(same_fd, &fd);
	271	}
	272
	273	static struct irq_fd find_irq_by_fd(int fd, int irqnum, int index_out)
	274	{
	275	struct irq_fd *irq;
	276	int i = 0;
	277	int fdi;
	278
191ef966 JJ	279	for (irq = active_fds; irq != NULL; irq = irq->next) {
	280	if ((irq->fd == fd) && (irq->irq == irqnum))
	281	break;
9b4f018d JD	282	i++;
9b4f018d JD	283	}
191ef966	284	if (irq == NULL) {
9b4f018d JD	285	printk("find_irq_by_fd doesn't have descriptor %d\n", fd);
	286	goto out;
	287	}
	288	fdi = os_get_pollfd(i);
191ef966	289	if ((fdi != -1) && (fdi != fd)) {
9b4f018d JD	290	printk("find_irq_by_fd - mismatch between active_fds and "
	291	"pollfds, fd %d vs %d, need %d\n", irq->fd,
	292	fdi, fd);
	293	irq = NULL;
	294	goto out;
	295	}
	296	*index_out = i;
	297	out:
191ef966	298	return irq;
9b4f018d JD	299	}
	300
	301	void reactivate_fd(int fd, int irqnum)
	302	{
	303	struct irq_fd *irq;
	304	unsigned long flags;
	305	int i;
	306
	307	flags = irq_lock();
	308	irq = find_irq_by_fd(fd, irqnum, &i);
191ef966	309	if (irq == NULL) {
9b4f018d JD	310	irq_unlock(flags);
	311	return;
	312	}
	313	os_set_pollfd(i, irq->fd);
	314	irq_unlock(flags);
	315
	316	/* This calls activate_fd, so it has to be outside the critical
	317	* section.
	318	*/
	319	maybe_sigio_broken(fd, irq->type);
	320	}
	321
	322	void deactivate_fd(int fd, int irqnum)
	323	{
	324	struct irq_fd *irq;
	325	unsigned long flags;
	326	int i;
	327
	328	flags = irq_lock();
	329	irq = find_irq_by_fd(fd, irqnum, &i);
191ef966	330	if (irq == NULL)
9b4f018d JD	331	goto out;
	332	os_set_pollfd(i, -1);
	333	out:
	334	irq_unlock(flags);
	335	}
	336
	337	int deactivate_all_fds(void)
	338	{
	339	struct irq_fd *irq;
	340	int err;
	341
191ef966	342	for (irq = active_fds; irq != NULL; irq = irq->next) {
9b4f018d	343	err = os_clear_fd_async(irq->fd);
191ef966 JJ	344	if (err)
191ef966 JJ	345	return err;
9b4f018d JD	346	}
	347	/* If there is a signal already queued, after unblocking ignore it */
	348	os_set_ioignore();
	349
191ef966	350	return 0;
9b4f018d JD	351	}
	352
	353	void forward_interrupts(int pid)
	354	{
	355	struct irq_fd *irq;
	356	unsigned long flags;
	357	int err;
	358
	359	flags = irq_lock();
191ef966	360	for (irq = active_fds; irq != NULL; irq = irq->next) {
9b4f018d	361	err = os_set_owner(irq->fd, pid);
191ef966	362	if (err < 0) {
9b4f018d JD	363	/* XXX Just remove the irq rather than
	364	* print out an infinite stream of these
	365	*/
	366	printk("Failed to forward %d to pid %d, err = %d\n",
	367	irq->fd, pid, -err);
	368	}
	369
	370	irq->pid = pid;
	371	}
	372	irq_unlock(flags);
	373	}
	374
1da177e4 LT	375	/*
	376	* do_IRQ handles all normal device IRQ's (the special
	377	* SMP cross-CPU interrupts have their own specific
	378	* handlers).
	379	*/
	380	unsigned int do_IRQ(int irq, union uml_pt_regs *regs)
	381	{
	382	irq_enter();
191ef966	383	__do_IRQ(irq, (struct pt_regs *)regs);
1da177e4 LT	384	irq_exit();
	385	return 1;
	386	}
	387
	388	int um_request_irq(unsigned int irq, int fd, int type,
	389	irqreturn_t (handler)(int, void , struct pt_regs *),
	390	unsigned long irqflags, const char * devname,
	391	void *dev_id)
	392	{
	393	int err;
	394
	395	err = request_irq(irq, handler, irqflags, devname, dev_id);
191ef966 JJ	396	if (err)
191ef966 JJ	397	return err;
1da177e4	398
191ef966	399	if (fd != -1)
1da177e4	400	err = activate_fd(irq, fd, type, dev_id);
191ef966	401	return err;
1da177e4 LT	402	}
	403	EXPORT_SYMBOL(um_request_irq);
	404	EXPORT_SYMBOL(reactivate_fd);
	405
	406	static DEFINE_SPINLOCK(irq_spinlock);
	407
	408	unsigned long irq_lock(void)
	409	{
	410	unsigned long flags;
	411
	412	spin_lock_irqsave(&irq_spinlock, flags);
191ef966	413	return flags;
1da177e4 LT	414	}
	415
	416	void irq_unlock(unsigned long flags)
	417	{
	418	spin_unlock_irqrestore(&irq_spinlock, flags);
	419	}
	420
dbce706e PBG	421	/* hw_interrupt_type must define (startup \|\| enable) &&
dbce706e PBG	422	* (shutdown \|\| disable) && end */
1da177e4 LT	423	static void dummy(unsigned int irq)
	424	{
	425	}
	426
dbce706e PBG	427	/* This is used for everything else than the timer. */
dbce706e PBG	428	static struct hw_interrupt_type normal_irq_type = {
1da177e4	429	.typename = "SIGIO",
dbce706e	430	.release = free_irq_by_irq_and_dev,
1da177e4 LT	431	.disable = dummy,
	432	.enable = dummy,
	433	.ack = dummy,
	434	.end = dummy
	435	};
	436
	437	static struct hw_interrupt_type SIGVTALRM_irq_type = {
	438	.typename = "SIGVTALRM",
dbce706e	439	.release = free_irq_by_irq_and_dev,
1da177e4 LT	440	.shutdown = dummy, /* never called */
	441	.disable = dummy,
	442	.enable = dummy,
	443	.ack = dummy,
	444	.end = dummy
	445	};
	446
	447	void __init init_IRQ(void)
	448	{
	449	int i;
	450
	451	irq_desc[TIMER_IRQ].status = IRQ_DISABLED;
	452	irq_desc[TIMER_IRQ].action = NULL;
	453	irq_desc[TIMER_IRQ].depth = 1;
	454	irq_desc[TIMER_IRQ].handler = &SIGVTALRM_irq_type;
	455	enable_irq(TIMER_IRQ);
191ef966	456	for (i = 1; i < NR_IRQS; i++) {
1da177e4 LT	457	irq_desc[i].status = IRQ_DISABLED;
	458	irq_desc[i].action = NULL;
	459	irq_desc[i].depth = 1;
dbce706e	460	irq_desc[i].handler = &normal_irq_type;
1da177e4 LT	461	enable_irq(i);
1da177e4 LT	462	}
1da177e4 LT	463	}
1da177e4 LT	464
75e5584c JD	465	int init_aio_irq(int irq, char name, irqreturn_t (handler)(int, void *,
	466	struct pt_regs *))
	467	{
	468	int fds[2], err;
	469
	470	err = os_pipe(fds, 1, 1);
191ef966	471	if (err) {
75e5584c JD	472	printk("init_aio_irq - os_pipe failed, err = %d\n", -err);
	473	goto out;
	474	}
	475
	476	err = um_request_irq(irq, fds[0], IRQ_READ, handler,
	477	SA_INTERRUPT \| SA_SAMPLE_RANDOM, name,
	478	(void *) (long) fds[0]);
191ef966	479	if (err) {
75e5584c JD	480	printk("init_aio_irq - : um_request_irq failed, err = %d\n",
	481	err);
	482	goto out_close;
	483	}
	484
	485	err = fds[1];
	486	goto out;
	487
	488	out_close:
	489	os_close_file(fds[0]);
	490	os_close_file(fds[1]);
	491	out:
191ef966	492	return err;
75e5584c	493	}