+/*
+ * 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/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 "linux/vs_context.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].chip->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 DEFINE_SPINLOCK(irq_lock);
+
+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.
+ */
+ spin_lock_irqsave(&irq_lock, flags);
+ 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.
+ */
+ spin_unlock_irqrestore(&irq_lock, flags);
+ kfree(tmp_pfd);
+ tmp_pfd = NULL;
+
+ tmp_pfd = um_kmalloc(n);
+ if (tmp_pfd == NULL)
+ goto out_kfree;
+
+ spin_lock_irqsave(&irq_lock, flags);
+ }
+ /*-------------*/
+
+ *last_irq_ptr = new_fd;
+ last_irq_ptr = &new_fd->next;
+
+ spin_unlock_irqrestore(&irq_lock, flags);
+
+ /* This calls activate_fd, so it has to be outside the critical
+ * section.
+ */
+ maybe_sigio_broken(fd, (type == IRQ_READ));
+
+ return(0);
+
+ out_unlock:
+ spin_unlock_irqrestore(&irq_lock, 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;
+
+ spin_lock_irqsave(&irq_lock, flags);
+ os_free_irq_by_cb(test, arg, active_fds, &last_irq_ptr);
+ spin_unlock_irqrestore(&irq_lock, 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;
+
+ spin_lock_irqsave(&irq_lock, flags);
+ irq = find_irq_by_fd(fd, irqnum, &i);
+ if (irq == NULL) {
+ spin_unlock_irqrestore(&irq_lock, flags);
+ return;
+ }
+ os_set_pollfd(i, irq->fd);
+ spin_unlock_irqrestore(&irq_lock, flags);
+
+ /* This calls activate_fd, so it has to be outside the critical
+ * section.
+ */
+ maybe_sigio_broken(fd, (irq->type == IRQ_READ));
+}
+
+void deactivate_fd(int fd, int irqnum)
+{
+ struct irq_fd *irq;
+ unsigned long flags;
+ int i;
+
+ spin_lock_irqsave(&irq_lock, flags);
+ irq = find_irq_by_fd(fd, irqnum, &i);
+ if (irq == NULL)
+ goto out;
+ os_set_pollfd(i, -1);
+ out:
+ spin_unlock_irqrestore(&irq_lock, 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;
+}
+
+#ifdef CONFIG_MODE_TT
+void forward_interrupts(int pid)
+{
+ struct irq_fd *irq;
+ unsigned long flags;
+ int err;
+
+ spin_lock_irqsave(&irq_lock, flags);
+ 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;
+ }
+ spin_unlock_irqrestore(&irq_lock, flags);
+}
+#endif
+
+/*
+ * 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)
+{
+ struct vx_info_save vxis;
+
+ irq_enter();
+
+ __enter_vx_admin(&vxis);
+ __do_IRQ(irq, (struct pt_regs *)regs);
+ __leave_vx_admin(&vxis);
+ 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);
+
+/* 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].chip = &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].chip = &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,
+ IRQF_DISABLED | IRQF_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;
+}