intr: Add user interrupt handling code for non-Linux case

* device/intr.c: Include <kern/assert.h>
(struct intr_list): New structure.
(user_intr_handlers): New array.
(user_irq_handler): New function.
(install_user_intr_handler): New function.

Message-Id: <20210330025830.63528-2-damien@zamaudio.com>

1 files changed, 80 insertions, 0 deletions

diff --git a/device/intr.c b/device/intr.c
index fbb9f495..ac213ecf 100644
--- a/device/intr.c
+++ b/device/intr.c
@@ -12,6 +12,7 @@
  * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  */
 
+#include <kern/assert.h>
 #include <device/intr.h>
 #include <device/device_types.h>
 #include <device/device_port.h>
@@ -26,6 +27,17 @@
 queue_head_t main_intr_queue;
 static boolean_t deliver_intr (int id, ipc_port_t dst_port);
 
+#ifndef LINUX_DEV
+#define SA_SHIRQ 0x04000000
+
+struct intr_list {
+  user_intr_t *user_intr;
+  unsigned long flags;
+  struct intr_list *next;
+};
+static struct intr_list *user_intr_handlers[NINTR];
+#endif
+
 static user_intr_t *
 search_intr (struct irqdev *dev, ipc_port_t dst_port)
 {
@@ -147,6 +159,74 @@ out:
   return ret;
 }
 
+#ifndef LINUX_DEV
+
+static void
+user_irq_handler (int id)
+{
+  struct intr_list *handler;
+  struct intr_list **prev = &user_intr_handlers[id];
+  user_intr_t *e;
+  spl_t s;
+
+  s = splhigh();
+
+  for (handler = *prev; handler; handler = handler->next)
+    {
+      e = handler->user_intr;
+      if (!deliver_user_intr(&irqtab, id, e))
+        {
+          /* We failed to deliver this interrupt, remove handler from list */
+	  *prev = handler->next;
+        }
+      prev = &handler->next;
+    }
+  splx(s);
+}
+
+int
+install_user_intr_handler (struct irqdev *dev, int id, unsigned long flags,
+			  user_intr_t *user_intr)
+{
+  unsigned int irq = dev->irq[id];
+  struct intr_list **head = &user_intr_handlers[id];
+  struct intr_list *new, *old = *head;
+  spl_t s;
+
+  assert (irq < NINTR);
+
+  /* Don't allow overriding hardclock/kdintr etc */
+  if ((ivect[irq] != user_irq_handler) && (ivect[irq] != intnull))
+    {
+      mach_print("You can't have this interrupt\n");
+      return D_ALREADY_OPEN;
+    }
+
+  if (old)
+    {
+      if (!(old->flags & flags & SA_SHIRQ))
+        {
+          mach_print ("Cannot share irq\n");
+          return D_ALREADY_OPEN;
+        }
+    }
+
+  new = (struct intr_list *)kalloc (sizeof (struct intr_list));
+  new->user_intr = user_intr;
+  new->flags = flags;
+
+  s = splhigh();
+  new->next = *head;
+  *head = new;
+  ivect[irq] = user_irq_handler;
+  iunit[irq] = (int)irq;
+  unmask_irq (irq);
+  splx(s);
+
+  return D_SUCCESS;
+}
+#endif
+
 void
 intr_thread (void)
 {