{install|remove}_io_interrupt_handler() now correctly handle the B_NO_ENABLE_COUNTER flag.

Lots of cleanup:
- moved B_NO_ENABLE_COUNTER flag definition out of int.h to KernelExport.h, as it's
  described in the BeBook (although it's probably not really used that often :))
- int.c no longer has any platform dependent code (+ 0x20 on interrupt numbers is gone);
  it's now entirely handled in the arch/x86/ section.
- the io_vectors[] is now statically initialized, instead of allocated from the heap
- removed {install|remove}_interrupt_handler(); they weren't that useful, arch_smp_init()
  is now calling install_io_interrupt_handler() correctly instead
- introduced a new arch_int.h header file that currently contains NUM_IO_VECTORS only
  (though on x86, it also has ARCH_INTERRUPT_BASE == 0x20).
- changed the return type from {install|remove}_io_interrupt_handler() from "long" to
  "status_t"
- rearranged and cleaned the PIC initialization code, made the PIC code more prominent
- changed comments that talk about a non existing 8239 (the PIC chip is actually 8259)
- moved arch/x86/interrupts.h to the source directory, as it's not used outside
- added BeOS compatible interrupts_enabled() function, that should replace our
  equivalent (and private) are_interrupts_enabled()


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@12477 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/os/drivers/KernelExport.h

@@ -1,7 +1,8 @@
 /* Kernel only exports for kernel add-ons
-** 
-** Distributed under the terms of the OpenBeOS License.
-*/
+ *
+ * Copyright 2005, Haiku Inc. All Rights Reserved.
+ * Distributed under the terms of the MIT License.
+ */
 #ifndef _KERNEL_EXPORT_H
 #define _KERNEL_EXPORT_H
 
@@ -15,6 +16,7 @@ extern "C" {
 #endif
 
 /*-------------------------------------------------------------*/
+/* interrupts and spinlocks */
 
 /* disable/restore interrupts on the current CPU */
 
@@ -36,16 +38,19 @@ extern void			release_spinlock(spinlock *lock);
 
 /* interrupt handling support for device drivers */
 
+typedef int32 (*interrupt_handler)(void *data);
+
 /* Values returned by interrupt handlers */
 #define B_UNHANDLED_INTERRUPT	0	/* pass to next handler */
 #define B_HANDLED_INTERRUPT		1	/* don't pass on */
 #define B_INVOKE_SCHEDULER		2	/* don't pass on; invoke the scheduler */
 
-typedef int32 (*interrupt_handler)(void *data);
+/* Flags that can be passed to install_io_interrupt_handler() */
+#define B_NO_ENABLE_COUNTER		1
 
-extern long 		install_io_interrupt_handler(long interrupt_number,
+extern status_t		install_io_interrupt_handler(long interrupt_number,
 						interrupt_handler handler, void *data, ulong flags);
-extern long 		remove_io_interrupt_handler(long interrupt_number,
+extern status_t		remove_io_interrupt_handler(long interrupt_number,
 						interrupt_handler handler, void	*data);