Add a facility for associating optional descriptions with active interrupt

handlers.  This is primarily intended as a way to allow devices that use
multiple interrupts (e.g. MSI) to meaningfully distinguish the various
interrupt handlers.
- Add a new BUS_DESCRIBE_INTR() method to the bus interface to associate
  a description with an active interrupt handler setup by BUS_SETUP_INTR.
  It has a default method (bus_generic_describe_intr()) which simply passes
  the request up to the parent device.
- Add a bus_describe_intr() wrapper around BUS_DESCRIBE_INTR() that supports
  printf(9) style formatting using var args.
- Reserve MAXCOMLEN bytes in the intr_handler structure to hold the name of
  an interrupt handler and copy the name passed to intr_event_add_handler()
  into that buffer instead of just saving the pointer to the name.
- Add a new intr_event_describe_handler() which appends a description string
  to an interrupt handler's name.
- Implement support for interrupt descriptions on amd64 and i386 by having
  the nexus(4) driver supply a custom bus_describe_intr method that invokes
  a new intr_describe() MD routine which in turn looks up the associated
  interrupt event and invokes intr_event_describe_handler().

Requested by:	many
Reviewed by:	scottl
MFC after:	2 weeks

1 files changed, 1 insertions, 0 deletions

diff --git a/sys/i386/include/intr_machdep.h b/sys/i386/include/intr_machdep.h
index f21e0bcf..bcff6c2 100644
--- a/sys/i386/include/intr_machdep.h
+++ b/sys/i386/include/intr_machdep.h
@@ -138,6 +138,7 @@ int	intr_bind(u_int vector, u_char cpu);
 #endif
 int	intr_config_intr(int vector, enum intr_trigger trig,
     enum intr_polarity pol);
+int	intr_describe(u_int vector, void *ih, const char *descr);
 void	intr_execute_handlers(struct intsrc *isrc, struct trapframe *frame);
 u_int	intr_next_cpu(void);
 struct intsrc *intr_lookup_source(int vector);