Specifications

Device Driver Entry Points
Unsolicited Interrupt Service Routine
Unsolicited Interrupt Service Routine
Services an interrupt from a MASSBUS disk that is not the result of a driver’s
request.
Specified in
Specify the name of the unsolicited interrupt service routine in the unsolic
argument to the DDTAB macro. This macro places the address of the routine into
DDT$L_UNSOLINT.
Called by
The MASSBUS adapter’s interrupt service routine (MBA$INT in module
ADPERRSUB of the SYSLOA facility) calls a driver’s unsolicited interrupt
service routine.
Synchronization
An unsolicited interrupt service routine is called, executes, and returns at device
IPL.
Context
Because the unsolicited interrupt service routine executes in kernel mode on the
interrupt stack, it can only refer to those addresses that reside in system (S0)
space.
Register usage
The unsolicited interrupt service routine must not alter the contents of registers
R6 through R11, the AP, or the FP.
Input
Location Contents
R4 Address of MBA’s configuration register
R5 Address of UCB
Exit
An unsolicited interrupt service routine issues an RSB instruction to return
control to the MASSBUS adapter’s interrupt service routine.
Description
Only drivers of MASSBUS disks must provide unsolicited interrupt service
routines. All other devices detect unsolicited interrupts in their interrupt service
routines.
The routine that handles these unsolicited interrupts must determine the nature
of the interrupt and act accordingly, depending on the characteristics of the device
and controller. Examples of such unsolicited interrupts include disks being placed
on line or taken off line.
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