if NT_INST else TITLE "Spin Locks" ;++ ; ; Copyright (c) 1989 Microsoft Corporation ; ; Module Name: ; ; spinlock.asm ; ; Abstract: ; ; This module implements stubbed x86 spinlock functions for ; any HAL. Some HALs may implement these function directly ; to minimize the amount of code required to perform a spinlock. ; (ie, out Raise & Lower irql in the fall through path) ; ; Author: ; ; Bryan Willman (bryanwi) 13 Dec 89 ; ; Environment: ; ; Kernel mode only. ; ; Revision History: ; ; Ken Reneris (kenr) 22-Jan-1991 ;-- PAGE .486p include callconv.inc ; calling convention macros include i386\kimacro.inc include hal386.inc include mac386.inc EXTRNP KfRaiseIrql,1,,FASTCALL EXTRNP KfLowerIrql,1,,FASTCALL EXTRNP _KeBugCheck,1,IMPORT EXTRNP _KeSetEventBoostPriority, 2, IMPORT EXTRNP _KeWaitForSingleObject,5, IMPORT ifdef NT_UP LOCK_ADD equ add LOCK_DEC equ dec else LOCK_ADD equ lock add LOCK_DEC equ lock dec endif _TEXT SEGMENT PARA PUBLIC 'CODE' ASSUME DS:FLAT, ES:FLAT, SS:FLAT, FS:NOTHING, GS:NOTHING PAGE SUBTTL "Acquire Kernel Spin Lock" ;++ ; ; KIRQL ; FASTCALL ; KfAcquireSpinLock ( ; IN PKSPIN_LOCK SpinLock ; ) ; ; Routine Description: ; ; This function raises to DISPATCH_LEVEL and then acquires a the ; kernel spin lock. ; ; Arguments: ; ; (ecx) = SpinLock - Supplies a pointer to an kernel spin lock. ; ; Return Value: ; ; OldIrql - pointer to place old irql ; ;-- align 16 cPublicFastCall KfAcquireSpinLock ,1 cPublicFpo 0,0 ; ; On a MP build we raise to dispatch_level ; and then acquire the spinlock ; push ecx ; Save address of spinlock mov ecx, DISPATCH_LEVEL fstCall KfRaiseIrql ; (al) = OldIrql pop ecx ; (ecx) -> spinlock ; ; Attempt to assert the lock ; sl10: ACQUIRE_SPINLOCK ecx, fstRET KfAcquireSpinLock ; ; Lock is owned, spin till it looks free, then go get it again. ; sl20: SPIN_ON_SPINLOCK ecx,sl10 fstENDP KfAcquireSpinLock PAGE SUBTTL "Acquire Synch Kernel Spin Lock" ;++ ; ; KIRQL ; FASTCALL ; KeAcquireSpinLockRaiseToSynch ( ; IN PKSPIN_LOCK SpinLock ; ) ; ; Routine Description: ; ; This function acquires the SpinLock at SYNCH_LEVEL. The function ; is optmized for hoter locks (the lock is tested before acquired, ; any spin should occur at OldIrql) ; ; Arguments: ; ; (ecx) = SpinLock - Supplies a pointer to an kernel spin lock. ; ; Return Value: ; ; OldIrql - pointer to place old irql ; ;-- align 16 cPublicFastCall KeAcquireSpinLockRaiseToSynch,1 cPublicFpo 0,0 ; ; Disable interrupts ; sls10: cli ; ; Try to obtain spinlock. Use non-lock operation first ; TEST_SPINLOCK ecx, ACQUIRE_SPINLOCK ecx, ; ; Got the lock, raise to SYNCH_LEVEL ; mov ecx, SYNCH_LEVEL fstCall KfRaiseIrql ; (al) = OldIrql ; ; Enable interrupts and return ; sti fstRET KeAcquireSpinLockRaiseToSynch ; ; Lock is owned, spin till it looks free, then go get it again. ; sls20: sti SPIN_ON_SPINLOCK ecx,sls10 fstENDP KeAcquireSpinLockRaiseToSynch PAGE SUBTTL "Release Kernel Spin Lock" ;++ ; ; VOID ; FASTCALL ; KfReleaseSpinLock ( ; IN PKSPIN_LOCK SpinLock, ; IN KIRQL NewIrql ; ) ; ; Routine Description: ; ; This function releases a kernel spin lock and lowers to the new irql ; ; Arguments: ; ; (ecx) = SpinLock - Supplies a pointer to an executive spin lock. ; (dl) = NewIrql - New irql value to set ; ; Return Value: ; ; None. ; ;-- align 16 cPublicFastCall KfReleaseSpinLock ,2 cPublicFpo 0,0 ifndef NT_UP RELEASE_SPINLOCK ecx ; release it endif mov ecx, edx ; (ecx) = NewIrql jmp @KfLowerIrql@4 ; to KeLowerIrql fstENDP KfReleaseSpinLock ;++ ; ; VOID ; FASTCALL ; ExAcquireFastMutex ( ; IN PFAST_MUTEX FastMutex ; ) ; ; Routine description: ; ; This function acquire ownership of the FastMutex ; ; Arguments: ; ; (ecx) = FastMutex - Supplies a pointer to the fast mutex ; ; Return Value: ; ; None. ; ;-- cPublicFastCall ExAcquireFastMutex,1 cPublicFpo 0,1 push ecx ; Push FAST_MUTEX addr mov ecx, APC_LEVEL fstCall KfRaiseIrql pop ecx ; (ecx) = Fast Mutex cPublicFpo 0,0 LOCK_DEC dword ptr [ecx].FmCount ; Get count jz short afm_ret ; The owner? Yes, Done inc dword ptr [ecx].FmContention cPublicFpo 0,1 push ecx push eax add ecx, FmEvent ; Wait on Event stdCall _KeWaitForSingleObject, pop eax pop ecx cPublicFpo 0,0 afm_ret: mov byte ptr [ecx].FmOldIrql, al fstRet ExAcquireFastMutex fstENDP ExAcquireFastMutex ;++ ; ; BOOLEAN ; FASTCALL ; ExTryToAcquireFastMutex ( ; IN PFAST_MUTEX FastMutex ; ) ; ; Routine description: ; ; This function acquire ownership of the FastMutex ; ; Arguments: ; ; (ecx) = FastMutex - Supplies a pointer to the fast mutex ; ; Return Value: ; ; Returns TRUE if the FAST_MUTEX was acquired; otherwise false ; ;-- cPublicFastCall ExTryToAcquireFastMutex,1 cPublicFpo 0,0 ; ; Try to acquire ; cmp dword ptr [ecx].FmCount, 1 ; Busy? jne short tam25 ; Yes, abort cPublicFpo 0,1 push ecx ; Push FAST_MUTEX mov ecx, APC_LEVEL fstCall KfRaiseIrql ; (al) = OldIrql mov ecx, [esp] ; Restore FAST_MUTEX mov [esp], eax ; Save OldIrql mov eax, 1 ; Value to compare against mov edx, 0 ; Value to set lock cmpxchg dword ptr [ecx].FmCount, edx ; Attempt to acquire jnz short tam20 ; got it? cPublicFpo 0,0 pop edx ; (edx) = OldIrql mov eax, 1 ; return TRUE mov byte ptr [ecx].FmOldIrql, dl ; Store OldIrql fstRet ExTryToAcquireFastMutex tam20: pop ecx ; (ecx) = OldIrql fstCall KfLowerIrql ; restore OldIrql tam25: xor eax, eax ; return FALSE fstRet ExTryToAcquireFastMutex ; all done fstENDP ExTryToAcquireFastMutex ;++ ; ; VOID ; FASTCALL ; ExReleaseFastMutex ( ; IN PFAST_MUTEX FastMutex ; ) ; ; Routine description: ; ; This function releases ownership of the FastMutex ; ; Arguments: ; ; (ecx) FastMutex - Supplies a pointer to the fast mutex ; ; Return Value: ; ; None. ; ;-- cPublicFastCall ExReleaseFastMutex,1 cPublicFpo 0,0 mov al, byte ptr [ecx].FmOldIrql ; (cl) = OldIrql LOCK_ADD dword ptr [ecx].FmCount, 1 ; Remove our count xchg ecx, eax ; (cl) = OldIrql js short rfm05 ; if < 0, set event jnz @KfLowerIrql@4 ; if != 0, don't set event rfm05: add eax, FmEvent push ecx stdCall _KeSetEventBoostPriority, pop ecx jmp @KfLowerIrql@4 fstENDP ExReleaseFastMutex _TEXT ends ENDIF ; NT_INST end