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8e64d96aeb
os_isatty can be made to disappear by moving maybe_sigio_broken from kernel to user code. This also lets write_sigio_workaround become static. 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>
470 lines
10 KiB
C
470 lines
10 KiB
C
/*
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* Copyright (C) 2000 Jeff Dike (jdike@karaya.com)
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* Licensed under the GPL
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* Derived (i.e. mostly copied) from arch/i386/kernel/irq.c:
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* Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
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*/
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#include "linux/config.h"
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#include "linux/kernel.h"
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#include "linux/module.h"
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#include "linux/smp.h"
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#include "linux/kernel_stat.h"
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#include "linux/interrupt.h"
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#include "linux/random.h"
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#include "linux/slab.h"
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#include "linux/file.h"
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#include "linux/proc_fs.h"
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#include "linux/init.h"
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#include "linux/seq_file.h"
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#include "linux/profile.h"
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#include "linux/hardirq.h"
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#include "asm/irq.h"
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#include "asm/hw_irq.h"
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#include "asm/atomic.h"
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#include "asm/signal.h"
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#include "asm/system.h"
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#include "asm/errno.h"
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#include "asm/uaccess.h"
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#include "user_util.h"
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#include "kern_util.h"
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#include "irq_user.h"
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#include "irq_kern.h"
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#include "os.h"
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#include "sigio.h"
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#include "misc_constants.h"
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/*
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* Generic, controller-independent functions:
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*/
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int show_interrupts(struct seq_file *p, void *v)
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{
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int i = *(loff_t *) v, j;
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struct irqaction * action;
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unsigned long flags;
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if (i == 0) {
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seq_printf(p, " ");
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for_each_online_cpu(j)
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seq_printf(p, "CPU%d ",j);
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seq_putc(p, '\n');
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}
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if (i < NR_IRQS) {
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spin_lock_irqsave(&irq_desc[i].lock, flags);
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action = irq_desc[i].action;
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if (!action)
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goto skip;
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seq_printf(p, "%3d: ",i);
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#ifndef CONFIG_SMP
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seq_printf(p, "%10u ", kstat_irqs(i));
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#else
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for_each_online_cpu(j)
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seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
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#endif
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seq_printf(p, " %14s", irq_desc[i].chip->typename);
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seq_printf(p, " %s", action->name);
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for (action=action->next; action; action = action->next)
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seq_printf(p, ", %s", action->name);
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seq_putc(p, '\n');
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skip:
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spin_unlock_irqrestore(&irq_desc[i].lock, flags);
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} else if (i == NR_IRQS) {
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seq_putc(p, '\n');
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}
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return 0;
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}
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struct irq_fd *active_fds = NULL;
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static struct irq_fd **last_irq_ptr = &active_fds;
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extern void free_irqs(void);
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void sigio_handler(int sig, union uml_pt_regs *regs)
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{
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struct irq_fd *irq_fd;
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int n;
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if (smp_sigio_handler())
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return;
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while (1) {
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n = os_waiting_for_events(active_fds);
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if (n <= 0) {
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if(n == -EINTR) continue;
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else break;
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}
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for (irq_fd = active_fds; irq_fd != NULL; irq_fd = irq_fd->next) {
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if (irq_fd->current_events != 0) {
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irq_fd->current_events = 0;
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do_IRQ(irq_fd->irq, regs);
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}
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}
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}
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free_irqs();
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}
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static DEFINE_SPINLOCK(irq_lock);
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int activate_fd(int irq, int fd, int type, void *dev_id)
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{
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struct pollfd *tmp_pfd;
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struct irq_fd *new_fd, *irq_fd;
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unsigned long flags;
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int pid, events, err, n;
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pid = os_getpid();
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err = os_set_fd_async(fd, pid);
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if (err < 0)
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goto out;
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new_fd = um_kmalloc(sizeof(*new_fd));
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err = -ENOMEM;
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if (new_fd == NULL)
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goto out;
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if (type == IRQ_READ)
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events = UM_POLLIN | UM_POLLPRI;
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else
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events = UM_POLLOUT;
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*new_fd = ((struct irq_fd) { .next = NULL,
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.id = dev_id,
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.fd = fd,
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.type = type,
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.irq = irq,
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.pid = pid,
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.events = events,
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.current_events = 0 } );
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/* Critical section - locked by a spinlock because this stuff can
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* be changed from interrupt handlers. The stuff above is done
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* outside the lock because it allocates memory.
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*/
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/* Actually, it only looks like it can be called from interrupt
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* context. The culprit is reactivate_fd, which calls
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* maybe_sigio_broken, which calls write_sigio_workaround,
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* which calls activate_fd. However, write_sigio_workaround should
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* only be called once, at boot time. That would make it clear that
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* this is called only from process context, and can be locked with
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* a semaphore.
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*/
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spin_lock_irqsave(&irq_lock, flags);
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for (irq_fd = active_fds; irq_fd != NULL; irq_fd = irq_fd->next) {
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if ((irq_fd->fd == fd) && (irq_fd->type == type)) {
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printk("Registering fd %d twice\n", fd);
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printk("Irqs : %d, %d\n", irq_fd->irq, irq);
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printk("Ids : 0x%p, 0x%p\n", irq_fd->id, dev_id);
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goto out_unlock;
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}
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}
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/*-------------*/
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if (type == IRQ_WRITE)
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fd = -1;
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tmp_pfd = NULL;
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n = 0;
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while (1) {
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n = os_create_pollfd(fd, events, tmp_pfd, n);
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if (n == 0)
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break;
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/* n > 0
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* It means we couldn't put new pollfd to current pollfds
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* and tmp_fds is NULL or too small for new pollfds array.
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* Needed size is equal to n as minimum.
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*
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* Here we have to drop the lock in order to call
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* kmalloc, which might sleep.
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* If something else came in and changed the pollfds array
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* so we will not be able to put new pollfd struct to pollfds
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* then we free the buffer tmp_fds and try again.
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*/
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spin_unlock_irqrestore(&irq_lock, flags);
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kfree(tmp_pfd);
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tmp_pfd = NULL;
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tmp_pfd = um_kmalloc(n);
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if (tmp_pfd == NULL)
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goto out_kfree;
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spin_lock_irqsave(&irq_lock, flags);
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}
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/*-------------*/
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*last_irq_ptr = new_fd;
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last_irq_ptr = &new_fd->next;
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spin_unlock_irqrestore(&irq_lock, flags);
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/* This calls activate_fd, so it has to be outside the critical
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* section.
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*/
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maybe_sigio_broken(fd, (type == IRQ_READ));
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return(0);
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out_unlock:
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spin_unlock_irqrestore(&irq_lock, flags);
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out_kfree:
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kfree(new_fd);
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out:
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return(err);
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}
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static void free_irq_by_cb(int (*test)(struct irq_fd *, void *), void *arg)
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{
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unsigned long flags;
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spin_lock_irqsave(&irq_lock, flags);
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os_free_irq_by_cb(test, arg, active_fds, &last_irq_ptr);
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spin_unlock_irqrestore(&irq_lock, flags);
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}
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struct irq_and_dev {
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int irq;
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void *dev;
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};
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static int same_irq_and_dev(struct irq_fd *irq, void *d)
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{
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struct irq_and_dev *data = d;
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return ((irq->irq == data->irq) && (irq->id == data->dev));
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}
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void free_irq_by_irq_and_dev(unsigned int irq, void *dev)
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{
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struct irq_and_dev data = ((struct irq_and_dev) { .irq = irq,
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.dev = dev });
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free_irq_by_cb(same_irq_and_dev, &data);
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}
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static int same_fd(struct irq_fd *irq, void *fd)
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{
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return (irq->fd == *((int *)fd));
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}
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void free_irq_by_fd(int fd)
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{
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free_irq_by_cb(same_fd, &fd);
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}
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static struct irq_fd *find_irq_by_fd(int fd, int irqnum, int *index_out)
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{
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struct irq_fd *irq;
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int i = 0;
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int fdi;
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for (irq = active_fds; irq != NULL; irq = irq->next) {
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if ((irq->fd == fd) && (irq->irq == irqnum))
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break;
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i++;
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}
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if (irq == NULL) {
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printk("find_irq_by_fd doesn't have descriptor %d\n", fd);
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goto out;
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}
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fdi = os_get_pollfd(i);
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if ((fdi != -1) && (fdi != fd)) {
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printk("find_irq_by_fd - mismatch between active_fds and "
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"pollfds, fd %d vs %d, need %d\n", irq->fd,
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fdi, fd);
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irq = NULL;
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goto out;
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}
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*index_out = i;
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out:
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return irq;
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}
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void reactivate_fd(int fd, int irqnum)
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{
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struct irq_fd *irq;
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unsigned long flags;
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int i;
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spin_lock_irqsave(&irq_lock, flags);
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irq = find_irq_by_fd(fd, irqnum, &i);
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if (irq == NULL) {
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spin_unlock_irqrestore(&irq_lock, flags);
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return;
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}
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os_set_pollfd(i, irq->fd);
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spin_unlock_irqrestore(&irq_lock, flags);
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/* This calls activate_fd, so it has to be outside the critical
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* section.
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*/
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maybe_sigio_broken(fd, (irq->type == IRQ_READ));
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}
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void deactivate_fd(int fd, int irqnum)
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{
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struct irq_fd *irq;
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unsigned long flags;
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int i;
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spin_lock_irqsave(&irq_lock, flags);
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irq = find_irq_by_fd(fd, irqnum, &i);
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if (irq == NULL)
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goto out;
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os_set_pollfd(i, -1);
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out:
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spin_unlock_irqrestore(&irq_lock, flags);
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}
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int deactivate_all_fds(void)
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{
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struct irq_fd *irq;
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int err;
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for (irq = active_fds; irq != NULL; irq = irq->next) {
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err = os_clear_fd_async(irq->fd);
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if (err)
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return err;
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}
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/* If there is a signal already queued, after unblocking ignore it */
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os_set_ioignore();
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return 0;
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}
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#ifdef CONFIG_MODE_TT
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void forward_interrupts(int pid)
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{
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struct irq_fd *irq;
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unsigned long flags;
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int err;
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spin_lock_irqsave(&irq_lock, flags);
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for (irq = active_fds; irq != NULL; irq = irq->next) {
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err = os_set_owner(irq->fd, pid);
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if (err < 0) {
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/* XXX Just remove the irq rather than
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* print out an infinite stream of these
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*/
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printk("Failed to forward %d to pid %d, err = %d\n",
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irq->fd, pid, -err);
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}
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irq->pid = pid;
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}
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spin_unlock_irqrestore(&irq_lock, flags);
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}
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#endif
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/*
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* do_IRQ handles all normal device IRQ's (the special
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* SMP cross-CPU interrupts have their own specific
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* handlers).
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*/
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unsigned int do_IRQ(int irq, union uml_pt_regs *regs)
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{
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irq_enter();
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__do_IRQ(irq, (struct pt_regs *)regs);
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irq_exit();
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return 1;
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}
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int um_request_irq(unsigned int irq, int fd, int type,
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irqreturn_t (*handler)(int, void *, struct pt_regs *),
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unsigned long irqflags, const char * devname,
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void *dev_id)
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{
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int err;
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err = request_irq(irq, handler, irqflags, devname, dev_id);
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if (err)
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return err;
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if (fd != -1)
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err = activate_fd(irq, fd, type, dev_id);
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return err;
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}
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EXPORT_SYMBOL(um_request_irq);
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EXPORT_SYMBOL(reactivate_fd);
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/* hw_interrupt_type must define (startup || enable) &&
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* (shutdown || disable) && end */
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static void dummy(unsigned int irq)
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{
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}
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/* This is used for everything else than the timer. */
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static struct hw_interrupt_type normal_irq_type = {
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.typename = "SIGIO",
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.release = free_irq_by_irq_and_dev,
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.disable = dummy,
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.enable = dummy,
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.ack = dummy,
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.end = dummy
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};
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static struct hw_interrupt_type SIGVTALRM_irq_type = {
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.typename = "SIGVTALRM",
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.release = free_irq_by_irq_and_dev,
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.shutdown = dummy, /* never called */
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.disable = dummy,
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.enable = dummy,
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.ack = dummy,
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.end = dummy
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};
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void __init init_IRQ(void)
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{
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int i;
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irq_desc[TIMER_IRQ].status = IRQ_DISABLED;
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irq_desc[TIMER_IRQ].action = NULL;
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irq_desc[TIMER_IRQ].depth = 1;
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irq_desc[TIMER_IRQ].chip = &SIGVTALRM_irq_type;
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enable_irq(TIMER_IRQ);
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for (i = 1; i < NR_IRQS; i++) {
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irq_desc[i].status = IRQ_DISABLED;
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irq_desc[i].action = NULL;
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irq_desc[i].depth = 1;
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irq_desc[i].chip = &normal_irq_type;
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enable_irq(i);
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}
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}
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int init_aio_irq(int irq, char *name, irqreturn_t (*handler)(int, void *,
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struct pt_regs *))
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{
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int fds[2], err;
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err = os_pipe(fds, 1, 1);
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if (err) {
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printk("init_aio_irq - os_pipe failed, err = %d\n", -err);
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goto out;
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}
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err = um_request_irq(irq, fds[0], IRQ_READ, handler,
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IRQF_DISABLED | IRQF_SAMPLE_RANDOM, name,
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(void *) (long) fds[0]);
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if (err) {
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printk("init_aio_irq - : um_request_irq failed, err = %d\n",
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err);
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goto out_close;
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}
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err = fds[1];
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goto out;
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out_close:
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os_close_file(fds[0]);
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os_close_file(fds[1]);
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out:
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return err;
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}
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