title "Software Interrupts" ;++ ; ; Copyright (c) 1992 Microsoft Corporation ; ; Module Name: ; ; ixswint.asm ; ; Abstract: ; ; This module implements the software interrupt handlers ; for x86 machines ; ; Author: ; ; John Vert (jvert) 2-Jan-1992 ; ; Environment: ; ; Kernel mode only. ; ; Revision History: ; ;-- .386p .xlist include hal386.inc include callconv.inc ; calling convention macros include i386\ix8259.inc include i386\kimacro.inc .list EXTRNP _KiDeliverApc,3,IMPORT EXTRNP _KiDispatchInterrupt,0,IMPORT EXTRNP Kei386EoiHelper,0,IMPORT EXTRNP _HalEndSystemInterrupt,2 extrn SWInterruptHandlerTable:dword extrn SWInterruptLookUpTable:byte ifdef IRQL_METRICS extrn HalApcSoftwareIntCount:dword extrn HalDpcSoftwareIntCount:dword endif _TEXT$02 SEGMENT DWORD PUBLIC 'CODE' ASSUME DS:FLAT, ES:FLAT, SS:FLAT, FS:NOTHING, GS:NOTHING page ,132 subttl "Request Software Interrupt" ;++ ; ; VOID ; HalRequestSoftwareInterrupt ( ; IN KIRQL RequestIrql ; ) ; ; Routine Description: ; ; This routine is used to request a software interrupt to the ; system. Also, this routine checks to see if any software ; interrupt should be generated. ; The following condition will cause software interrupt to ; be simulated: ; any software interrupt which has higher priority than ; current IRQL's is pending. ; ; NOTE: This routine simulates software interrupt as long as ; any pending SW interrupt level is higher than the current ; IRQL, even when interrupts are disabled. ; ; Arguments: ; ; (cl) = RequestIrql - Supplies the request IRQL value ; ; Return Value: ; ; None. ; ;-- cPublicFastCall HalRequestSoftwareInterrupt ,1 cPublicFpo 0, 1 mov eax,1 shl eax, cl ; convert to mask pushfd ; save interrupt mode cli ; disable interrupt or PCR[PcIRR], eax ; set the request bit mov cl, PCR[PcIrql] ; get current IRQL mov eax, PCR[PcIRR] ; get SW interrupt request register and eax, 3 ; mask off pending HW interrupts xor edx, edx mov dl, SWInterruptLookUpTable[eax] ; get the highest pending ; software interrupt level cmp dl, cl ; Is highest SW int level > irql? jbe short KsiExit ; No, jmp ksiexit call SWInterruptHandlerTable[edx*4] ; yes, simulate interrupt ; to the appropriate handler KsiExit: popfd ; restore original interrupt mode fstRET HalRequestSoftwareInterrupt fstENDP HalRequestSoftwareInterrupt page ,132 subttl "Request Software Interrupt" ;++ ; ; VOID ; HalClearSoftwareInterrupt ( ; IN KIRQL RequestIrql ; ) ; ; Routine Description: ; ; This routine is used to clear a possible pending software interrupt. ; Support for this function is optional, and allows the kernel to ; reduce the number of spurious software interrupts it receives/ ; ; Arguments: ; ; (cl) = RequestIrql - Supplies the request IRQL value ; ; Return Value: ; ; None. ; ;-- cPublicFastCall HalClearSoftwareInterrupt ,1 cPublicFpo 0, 0 mov eax,1 shl eax, cl ; convert to mask not eax and PCR[PcIRR], eax ; clear pending irr bit fstRET HalClearSoftwareInterrupt fstENDP HalClearSoftwareInterrupt page ,132 subttl "Dispatch Interrupt" ;++ ; ; VOID ; HalpDispatchInterrupt( ; VOID ; ); ; ; Routine Description: ; ; This routine is the interrupt handler for a software interrupt generated ; at DISPATCH_LEVEL. Its function is to save the machine state, raise ; Irql to DISPATCH_LEVEL, dismiss the interrupt, and call the DPC ; delivery routine. ; ; Arguments: ; ; None ; Interrupt is disabled ; ; Return Value: ; ; None. ; ;-- ENTER_DR_ASSIST hdpi_a, hdpi_t align dword public _HalpDispatchInterrupt _HalpDispatchInterrupt proc ifdef IRQL_METRICS lock inc HalDpcSoftwareIntCount endif ; ; Create IRET frame on stack ; pop eax pushfd push cs push eax ; ; Save machine state on trap frame ; ENTER_INTERRUPT hdpi_a, hdpi_t .FPO ( FPO_LOCALS+1, 0, 0, 0, 0, FPO_TRAPFRAME ) public _HalpDispatchInterrupt2ndEntry _HalpDispatchInterrupt2ndEntry: ; Save previous IRQL and set new priority level push PCR[PcIrql] ; save previous IRQL mov byte ptr PCR[PcIrql], DISPATCH_LEVEL; set new irql and dword ptr PCR[PcIRR], not (1 shl DISPATCH_LEVEL) ; clear the pending bit in IRR ; ; Now it is safe to enable interrupt to allow higher priority interrupt ; to come in. ; sti ; ; Go do Dispatch Interrupt processing ; stdCall _KiDispatchInterrupt ; ; Do interrupt exit processing ; SOFT_INTERRUPT_EXIT ; will do an iret _HalpDispatchInterrupt endp page ,132 subttl "APC Interrupt" ;++ ; ; HalpApcInterrupt( ; VOID ; ); ; ; Routine Description: ; ; This routine is entered as the result of a software interrupt generated ; at APC_LEVEL. Its function is to save the machine state, raise Irql to ; APC_LEVEL, dismiss the interrupt, and call the APC delivery routine. ; ; Arguments: ; ; None ; Interrupt is Disabled ; ; Return Value: ; ; None. ; ;-- ENTER_DR_ASSIST hapc_a, hapc_t align dword public _HalpApcInterrupt _HalpApcInterrupt proc ifdef IRQL_METRICS lock inc HalApcSoftwareIntCount endif ; ; Create IRET frame on stack ; pop eax pushfd push cs push eax ; ; Save machine state in trap frame ; ENTER_INTERRUPT hapc_a, hapc_t .FPO ( FPO_LOCALS+1, 0, 0, 0, 0, FPO_TRAPFRAME ) public _HalpApcInterrupt2ndEntry _HalpApcInterrupt2ndEntry: ; ; Save previous IRQL and set new priority level ; push PCR[PcIrql] ; save previous Irql mov byte ptr PCR[PcIrql], APC_LEVEL ; set new Irql and dword ptr PCR[PcIRR], not (1 shl APC_LEVEL) ; dismiss pending APC ; ; Now it is safe to enable interrupt to allow higher priority interrupt ; to come in. ; sti ; ; call the APC delivery routine. ; mov eax, [ebp]+TsSegCs ; get interrupted code's CS and eax, MODE_MASK ; extract the mode test dword ptr [ebp]+TsEFlags, EFLAGS_V86_MASK jz short @f or eax, MODE_MASK ; If v86 frame, then set user_mode @@: ; ; call APC deliver routine ; Previous mode ; Null exception frame ; Trap frame stdCall _KiDeliverApc, ; ; ; Do interrupt exit processing ; SOFT_INTERRUPT_EXIT ; will do an iret _HalpApcInterrupt endp _TEXT$02 ends end