opensolaris man page for ddi_intr_hilevel

ddi_intr_hilevel(9F)					   Kernel Functions for Drivers 				      ddi_intr_hilevel(9F)

NAME
       ddi_intr_hilevel - indicate interrupt handler type

SYNOPSIS
       #include <sys/ddi.h>
       #include <sys/sunddi.h>

       int ddi_intr_hilevel(dev_info_t *dip, uint_t inumber);

INTERFACE LEVEL
       Solaris	DDI specific (Solaris DDI). This interface is obsolete. Use the new interrupt interfaces referenced in Intro(9F). Refer to Writing
       Device Drivers for more information.

PARAMETERS
       dip	  Pointer to dev_info structure.

       inumber	  Interrupt number.

DESCRIPTION
       The ddi_intr_hilevel() function returns non-zero if the specified interrupt is a "high level" interrupt.

       High level interrupts must be handled without using system services that manipulate thread or process states, because these interrupts  are
       not blocked by the scheduler.

       In addition, high level interrupt handlers must take care to do a minimum of work because they are not preemptable.

       A  typical  high  level	interrupt handler would put data into a circular buffer and schedule a soft interrupt by calling ddi_trigger_soft-
       intr(). The circular buffer could be protected by using a mutex that was properly initialized for the interrupt handler.

       The ddi_intr_hilevel() function can be used before calling ddi_add_intr() to decide which type of interrupt handler should  be  used.  Most
       device  drivers	are  designed  with  the  knowledge  that the devices they support will always generate low level interrupts, however some
       devices, for example those using SBus or VME bus level 6 or 7 interrupts must use this test because on some machines those  interrupts  are
       high level (above the scheduler level) and on other machines they are not.

RETURN VALUES
       non-zero    indicates a high-level interrupt.

CONTEXT
       These functions can be called from useruser, interrupt, or kernel context.

ATTRIBUTES
       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Obsolete			   |
       +-----------------------------+-----------------------------+

SEE ALSO
       ddi_add_intr(9F), Intro(9F), mutex(9F)

       Writing Device Drivers

SunOS 5.11							    16 Jan 2006 					      ddi_intr_hilevel(9F)