Pull acpi_bus_register_driver into release branch
[pandora-kernel.git] / arch / um / kernel / irq.c
index bbf94bf..2ffda01 100644 (file)
@@ -31,6 +31,8 @@
 #include "irq_user.h"
 #include "irq_kern.h"
 #include "os.h"
+#include "sigio.h"
+#include "misc_constants.h"
 
 /*
  * Generic, controller-independent functions:
@@ -77,6 +79,299 @@ skip:
        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
@@ -85,7 +380,7 @@ skip:
 unsigned int do_IRQ(int irq, union uml_pt_regs *regs)
 {
        irq_enter();
-       __do_IRQ(irq, (struct pt_regs *) regs);
+       __do_IRQ(irq, (struct pt_regs *)regs);
        irq_exit();
        return 1;
 }
@@ -98,12 +393,12 @@ int um_request_irq(unsigned int irq, int fd, int type,
        int err;
 
        err = request_irq(irq, handler, irqflags, devname, dev_id);
-       if(err)
-               return(err);
+       if (err)
+               return err;
 
-       if(fd != -1)
+       if (fd != -1)
                err = activate_fd(irq, fd, type, dev_id);
-       return(err);
+       return err;
 }
 EXPORT_SYMBOL(um_request_irq);
 EXPORT_SYMBOL(reactivate_fd);
@@ -115,7 +410,7 @@ unsigned long irq_lock(void)
        unsigned long flags;
 
        spin_lock_irqsave(&irq_spinlock, flags);
-       return(flags);
+       return flags;
 }
 
 void irq_unlock(unsigned long flags)
@@ -158,7 +453,7 @@ void __init init_IRQ(void)
        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++){
+       for (i = 1; i < NR_IRQS; i++) {
                irq_desc[i].status = IRQ_DISABLED;
                irq_desc[i].action = NULL;
                irq_desc[i].depth = 1;
@@ -173,7 +468,7 @@ int init_aio_irq(int irq, char *name, irqreturn_t (*handler)(int, void *,
        int fds[2], err;
 
        err = os_pipe(fds, 1, 1);
-       if(err){
+       if (err) {
                printk("init_aio_irq - os_pipe failed, err = %d\n", -err);
                goto out;
        }
@@ -181,7 +476,7 @@ int init_aio_irq(int irq, char *name, irqreturn_t (*handler)(int, void *,
        err = um_request_irq(irq, fds[0], IRQ_READ, handler,
                             SA_INTERRUPT | SA_SAMPLE_RANDOM, name,
                             (void *) (long) fds[0]);
-       if(err){
+       if (err) {
                printk("init_aio_irq - : um_request_irq failed, err = %d\n",
                       err);
                goto out_close;
@@ -194,5 +489,5 @@ int init_aio_irq(int irq, char *name, irqreturn_t (*handler)(int, void *,
        os_close_file(fds[0]);
        os_close_file(fds[1]);
  out:
-       return(err);
+       return err;
 }