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// TITLE("Miscellaneous Kernel Functions")//++//// Copyright (c) 1990 Microsoft Corporation//// Module Name://// miscs.s//// Abstract://// This module implements machine dependent miscellaneous kernel functions.// Functions are provided to request a software interrupt, continue thread// execution, and perform last chance exception processing.//// Author://// David N. Cutler (davec) 31-Mar-1990//// Environment://// Kernel mode only.//// Revision History://// Thomas Van Baak (tvb) 29-Jul-1992//// Adapted for Alpha AXP.////--
#include "ksalpha.h"
SBTTL("Request Software Interrupt")//++//// VOID// KiRequestSoftwareInterrupt (// KIRQL RequestIrql// )//// Routine Description://// This function requests a software interrupt at the specified IRQL// level.//// Arguments://// RequestIrql (a0) - Supplies the requested IRQL value.//// Return Value://// None.////--
LEAF_ENTRY(KiRequestSoftwareInterrupt)
//// If an interrupt routine is active, do not request an interrupt from the// PAL. Indicate the interrupt has been requested in the PRCB. The interrupt// exit code will dispatch the software interrupt directly.//
GET_PROCESSOR_CONTROL_BLOCK_BASE // get current prcb address
LDP t0, PbInterruptTrapFrame(v0) // get interrupt trap frame beq t0, 10f // if eq, no interrupt active blbs a0, 10f // if lbs, APC interrupt requested stl a0, PbSoftwareInterrupts(v0) // set interrupt request bit in PRCB ret zero, (ra) //
//// Request software interrupt.//
10: REQUEST_SOFTWARE_INTERRUPT // request software interrupt
ret zero, (ra) // return
.end KiRequestSoftwareInterrupt SBTTL("Continue Execution System Service")//++//// NTSTATUS// NtContinue (// IN PCONTEXT ContextRecord,// IN BOOLEAN TestAlert// )//// Routine Description://// This routine is called as a system service to continue execution after// an exception has occurred. Its function is to transfer information from// the specified context record into the trap frame that was built when the// system service was executed, and then exit the system as if an exception// had occurred.//// Arguments://// ContextRecord (a0) - Supplies a pointer to a context record.//// TestAlert (a1) - Supplies a boolean value that specifies whether alert// should be tested for the previous processor mode.//// N.B. Register fp is assumed to contain the address of a trap frame.//// Return Value://// Normally there is no return from this routine. However, if the specified// context record is misaligned or is not accessible, then the appropriate// status code is returned.////--
NESTED_ENTRY(NtContinue, ExceptionFrameLength, zero)
lda sp, -ExceptionFrameLength(sp) // allocate exception frame stq ra, ExIntRa(sp) // save return address
PROLOGUE_END
//// Save the nonvolatile machine state so that it can be restored by exception// exit if it is not overwritten by the specified context record.//
stq s0, ExIntS0(sp) // save nonvolatile integer state stq s1, ExIntS1(sp) // stq s2, ExIntS2(sp) // stq s3, ExIntS3(sp) // stq s4, ExIntS4(sp) // stq s5, ExIntS5(sp) //
stt f2, ExFltF2(sp) // save nonvolatile floating state stt f3, ExFltF3(sp) // stt f4, ExFltF4(sp) // stt f5, ExFltF5(sp) // stt f6, ExFltF6(sp) // stt f7, ExFltF7(sp) // stt f8, ExFltF8(sp) // stt f9, ExFltF9(sp) //
//// Transfer information from the context frame to the exception and trap// frames.//
mov a1, s0 // preserve test alert argument in s0 mov sp, a1 // set address of exception frame mov fp, a2 // set address of trap frame bsr ra, KiContinue // transfer context to kernel frames
//// If the kernel continuation routine returns success, then exit via the// exception exit code. Otherwise return to the system service dispatcher.//
bne v0, 20f // if ne, transfer failed
//// Check to determine if alert should be tested for the previous processor// mode and restore the previous mode in the thread object.//
GET_CURRENT_THREAD // get current thread address
LDP t3, TrTrapFrame(fp) // get old trap frame address ldl t2, TrPreviousMode(fp) // get old previous mode LoadByte(a0, ThPreviousMode(v0)) // get current previous mode STP t3, ThTrapFrame(v0) // restore old trap frame address StoreByte(t2, ThPreviousMode(v0)) // restore old previous mode beq s0, 10f // if eq, don't test for alert bsr ra, KeTestAlertThread // test alert for current thread
//// Exit the system via exception exit which will restore the nonvolatile// machine state.//
10: br zero, KiExceptionExit // finish in exception exit
//// Context record is misaligned or not accessible.//
20: ldq ra, ExIntRa(sp) // restore return address lda sp, ExceptionFrameLength(sp) // deallocate stack frame ret zero, (ra) // return
.end NtContinue SBTTL("Raise Exception System Service")//++//// NTSTATUS// NtRaiseException (// IN PEXCEPTION_RECORD ExceptionRecord,// IN PCONTEXT ContextRecord,// IN BOOLEAN FirstChance// )//// Routine Description://// This routine is called as a system service to raise an exception.// The exception can be raised as a first or second chance exception.//// Arguments://// ExceptionRecord (a0) - Supplies a pointer to an exception record.//// ContextRecord (a1) - Supplies a pointer to a context record.//// FirstChance (a2) - Supplies a boolean value that determines whether// this is the first (TRUE) or second (FALSE) chance for dispatching// the exception.//// N.B. Register fp is assumed to contain the address of a trap frame.//// Return Value://// Normally there is no return from this routine. However, if the specified// context record or exception record is misaligned or is not accessible,// then the appropriate status code is returned.////--
NESTED_ENTRY(NtRaiseException, ExceptionFrameLength, zero)
lda sp, -ExceptionFrameLength(sp) // allocate exception frame stq ra, ExIntRa(sp) // save return address stq s0, ExIntS0(sp) // save S0 and S1 in the prologue stq s1, ExIntS1(sp) // so that Get/SetContext can find // the right ones. PROLOGUE_END
//// Save the nonvolatile machine state so that it can be restored by exception// exit if it is not overwritten by the specified context record.//
stq s2, ExIntS2(sp) // stq s3, ExIntS3(sp) // stq s4, ExIntS4(sp) // stq s5, ExIntS5(sp) //
stt f2, ExFltF2(sp) // save nonvolatile floating state stt f3, ExFltF3(sp) // stt f4, ExFltF4(sp) // stt f5, ExFltF5(sp) // stt f6, ExFltF6(sp) // stt f7, ExFltF7(sp) // stt f8, ExFltF8(sp) // stt f9, ExFltF9(sp) //
//// Call the raise exception kernel routine which will marshall the arguments// and then call the exception dispatcher.//// KiRaiseException requires five arguments: the first two are the same as// the first two of this function and the other three are set here.//
mov a2, a4 // set first chance argument mov sp, a2 // set address of exception frame mov fp, a3 // set address of trap frame bsr ra, KiRaiseException // call raise exception routine
//// If the raise exception routine returns success, then exit via the exception// exit code. Otherwise return to the system service dispatcher.//
bis v0, zero, t0 // save return status LDP t1, TrTrapFrame(fp) // get old trap frame address
GET_CURRENT_THREAD // get current thread address
bne t0, 10f // if ne, dispatch not successful STP t1, ThTrapFrame(v0) // restore old trap frame address
//// Exit the system via exception exit which will restore the nonvolatile// machine state.//
br zero, KiExceptionExit // finish in exception exit
//// The context or exception record is misaligned or not accessible, or the// exception was not handled.//
10: ldq ra, ExIntRa(sp) // restore return address lda sp, ExceptionFrameLength(sp) // deallocate stack frame ret zero, (ra) // return
.end NtRaiseException SBTTL("Instruction Memory Barrier")//++//// VOID// KiImb (// VOID// )//// Routine Description://// This routine is called to flush the instruction cache on the// current processor.//// Arguments://// None.//// Return Value://// None.////--
LEAF_ENTRY(KiImb)
IMB // flush the icache via PALcode
ret zero, (ra) // return
.end KiImb SBTTL("Memory Barrier")//++//// VOID// KiImb (// VOID// )//// Routine Description://// This routine is called to issue a memory barrier on the current// processor.//// Arguments://// None.//// Return Value://// None.////--
LEAF_ENTRY(KiMb)
mb // memory barrier
ret zero, (ra) // return
.end KiMb //++//// VOID// KiEnablePALAlignmentFixups(// VOID // )//// Routine Description://// Enable PAL fixups and PAL counting of alignment faults.//// Arguments://// None//// Return Value://// None.////--
LEAF_ENTRY(KiEnablePALAlignmentFixups)
ENABLE_ALIGNMENT_FIXUPS // enable alignment fixups
ret zero, (ra) // return
.end KiEnablePALAlignmentFixups //++//// VOID// KiDisablePALAlignmentFixups(// VOID // )//// Routine Description://// Disable PAL fixups and force all alignment faults to// the kernel.//// Arguments://// None//// Return Value://// None.////--
LEAF_ENTRY(KiDisablePALAlignmentFixups)
DISABLE_ALIGNMENT_FIXUPS // disable alignment fixups
ret zero, (ra) // return
.end KiDisablePALAlignmentFixups
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