Manual Pages for UNIX Operating System command usage for man ddi_intr_hilevel

Kernel Functions for Drivers                 ddi_intr_hilevel(9F)



NAME
     ddi_intr_hilevel - indicate interrupt handler type

SYNOPSIS
     #include 
     #include 



     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  This  interface  is
     obsolete.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 informa-
     tion.

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_softintr(). The circular buffer  could  be  pro-
     tected  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



SunOS 5.11          Last change: 16 Jan 2006                    1






Kernel Functions for Drivers                 ddi_intr_hilevel(9F)



     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  attri-
     butes:



     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Interface Stability         | Obsolete                    |
    |_____________________________|_____________________________|


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


     Writing Device Drivers

























SunOS 5.11          Last change: 16 Jan 2006                    2