Add preliminary support for binding interrupts to CPUs:

- Add a new intr_event method ie_assign_cpu() that is invoked when the MI
  code wishes to bind an interrupt source to an individual CPU.  The MD
  code may reject the binding with an error.  If an assign_cpu function
  is not provided, then the kernel assumes the platform does not support
  binding interrupts to CPUs and fails all requests to do so.
- Bind ithreads to CPUs on their next execution loop once an interrupt
  event is bound to a CPU.  Only shared ithreads are bound.  We currently
  leave private ithreads for drivers using filters + ithreads in the
  INTR_FILTER case unbound.
- A new intr_event_bind() routine is used to bind an interrupt event to
  a CPU.
- Implement binding on amd64 and i386 by way of the existing pic_assign_cpu
  PIC method.
- For x86, provide a 'intr_bind(IRQ, cpu)' wrapper routine that looks up
  an interrupt source and binds its interrupt event to the specified CPU.
  MI code can currently (ab)use this by doing:

	intr_bind(rman_get_start(irq_res), cpu);

  however, I plan to add a truly MI interface (probably a bus_bind_intr(9))
  where the implementation in the x86 nexus(4) driver would end up calling
  intr_bind() internally.

Requested by:	kmacy, gallatin, jeff
Tested on:	{amd64, i386} x {regular, INTR_FILTER}

1 files changed, 9 insertions, 4 deletions

diff --git a/sys/sys/interrupt.h b/sys/sys/interrupt.h
index b110374..54cd0e4 100644
--- a/sys/sys/interrupt.h
+++ b/sys/sys/interrupt.h
@@ -73,6 +73,7 @@ struct intr_event {
 	void		*ie_source;	/* Cookie used by MD code. */
 	struct intr_thread *ie_thread;	/* Thread we are connected to. */
 	void		(*ie_enable)(void *);
+	int		(*ie_assign_cpu)(void *, u_char);
 #ifdef INTR_FILTER
 	void		(*ie_eoi)(void *);
 	void		(*ie_disab)(void *);
@@ -81,6 +82,7 @@ struct intr_event {
 	int		ie_count;	/* Loop counter. */
 	int		ie_warncnt;	/* Rate-check interrupt storm warns. */
 	struct timeval	ie_warntm;
+	u_char		ie_cpu;		/* CPU this event is bound to. */
 };
 
 /* Interrupt event flags kept in ie_flags. */
@@ -127,15 +129,18 @@ u_char	intr_priority(enum intr_type flags);
 int	intr_event_add_handler(struct intr_event *ie, const char *name,
 	    driver_filter_t filter, driver_intr_t handler, void *arg, 
 	    u_char pri, enum intr_type flags, void **cookiep);	    
+int	intr_event_bind(struct intr_event *ie, u_char cpu);
 #ifndef INTR_FILTER
 int	intr_event_create(struct intr_event **event, void *source,
-	    int flags, void (*enable)(void *), const char *fmt, ...)
-	    __printflike(5, 6);
+	    int flags, void (*enable)(void *),
+	    int (*assign_cpu)(void *, u_char), const char *fmt, ...)
+	    __printflike(6, 7);
 #else
 int	intr_event_create(struct intr_event **event, void *source,
 	    int flags, void (*enable)(void *), void (*eoi)(void *), 
-	    void (*disab)(void *), const char *fmt, ...)
-	    __printflike(7, 8);
+	    void (*disab)(void *), int (*assign_cpu)(void *, u_char),
+	    const char *fmt, ...)
+	    __printflike(8, 9);
 #endif
 int	intr_event_destroy(struct intr_event *ie);
 int	intr_event_remove_handler(void *cookie);