Source code of Windows XP (NT5)
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1392 lines
34 KiB

if NT_INST
else
TITLE "Spin Locks"
;++
;
; Copyright (c) 1989-1998 Microsoft Corporation
;
; Module Name:
;
; spinlock.asm
;
; Abstract:
;
; This module implements x86 spinlock functions for the PC+MP HAL.
;
; Author:
;
; Bryan Willman (bryanwi) 13 Dec 89
;
; Environment:
;
; Kernel mode only.
;
; Revision History:
;
; Ron Mosgrove (o-RonMo) Dec 93 - modified for PC+MP HAL.
;--
PAGE
.486p
include callconv.inc ; calling convention macros
include i386\kimacro.inc
include hal386.inc
include mac386.inc
include apic.inc
include ntapic.inc
EXTRNP _KeBugCheckEx,5,IMPORT
EXTRNP KfRaiseIrql, 1,,FASTCALL
EXTRNP KfLowerIrql, 1,,FASTCALL
EXTRNP _KeSetEventBoostPriority, 2, IMPORT
EXTRNP _KeWaitForSingleObject,5, IMPORT
extrn _HalpVectorToIRQL:byte
extrn _HalpIRQLtoTPR:byte
ifdef NT_UP
LOCK_ADD equ add
LOCK_DEC equ dec
LOCK_CMPXCHG equ cmpxchg
else
LOCK_ADD equ lock add
LOCK_DEC equ lock dec
LOCK_CMPXCHG equ lock cmpxchg
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 a kernel spin lock.
;
; Return Value:
;
; OldIrql (TOS+8) - pointer to place old irql.
;
;--
align 16
cPublicFastCall KfAcquireSpinLock ,1
cPublicFpo 0,0
mov edx, dword ptr APIC[LU_TPR] ; (edx) = Old Priority (Vector)
mov dword ptr APIC[LU_TPR], DPC_VECTOR ; Write New Priority to the TPR
shr edx, 4
movzx eax, _HalpVectorToIRQL[edx] ; (al) = OldIrql
ifndef NT_UP
;
; Attempt to assert the lock
;
sl10: ACQUIRE_SPINLOCK ecx,<short sl20>
fstRET KfAcquireSpinLock
;
; Lock is owned, spin till it looks free, then go get it again.
;
align dword
sl20: SPIN_ON_SPINLOCK ecx,sl10
endif
fstRET KfAcquireSpinLock
fstENDP KfAcquireSpinLock
PAGE
SUBTTL "Acquire Kernel Spin Lock"
;++
;
; KIRQL
; FASTCALL
; KeAcquireSpinLockRaiseToSynch (
; IN PKSPIN_LOCK SpinLock
; )
;
; Routine Description:
;
; This function acquires the SpinLock at SYNCH_LEVEL. The function
; is optimized for hotter locks (the lock is tested before acquiring,
; and any spin occurs at OldIrql).
;
; Arguments:
;
; (ecx) = SpinLock - Supplies a pointer to a kernel spin lock.
;
; Return Value:
;
; OldIrql (TOS+8) - pointer to place old irql.
;
;--
align 16
cPublicFastCall KeAcquireSpinLockRaiseToSynch,1
cPublicFpo 0,0
mov edx, dword ptr APIC[LU_TPR] ; (ecx) = Old Priority (Vector)
mov eax, edx
shr eax, 4
movzx eax, _HalpVectorToIRQL[eax] ; (al) = OldIrql
ifdef NT_UP
mov dword ptr APIC[LU_TPR], APIC_SYNCH_VECTOR ; Write New Priority to the TPR
fstRET KeAcquireSpinLockRaiseToSynch
else
;
; Test lock
;
TEST_SPINLOCK ecx,<short sls30>
;
; Raise irql.
;
sls10: mov dword ptr APIC[LU_TPR], APIC_SYNCH_VECTOR
;
; Attempt to assert the lock
;
ACQUIRE_SPINLOCK ecx,<short sls20>
fstRET KeAcquireSpinLockRaiseToSynch
;
; Lock is owned, spin till it looks free, then go get it
;
align dword
sls20: mov dword ptr APIC[LU_TPR], edx
align dword
sls30: SPIN_ON_SPINLOCK ecx,sls10
endif
fstENDP KeAcquireSpinLockRaiseToSynch
ifndef NT_UP
;++
;
; KIRQL
; FASTCALL
; KeAcquireSpinLockRaiseToSynchMCE (
; IN PKSPIN_LOCK SpinLock
; )
;
; Routine Description:
;
; This function performs the same function as KeAcquireSpinLockRaiseToSynch
; but provides a work around for an IFU errata for Pentium Pro processors
; prior to stepping 619.
;
; Arguments:
;
; (ecx) = SpinLock - Supplies a pointer to a kernel spin lock.
;
; Return Value:
;
; OldIrql (TOS+8) - pointer to place old irql.
;
;--
align 16
cPublicFastCall KeAcquireSpinLockRaiseToSynchMCE,1
cPublicFpo 0,0
mov edx, dword ptr APIC[LU_TPR] ; (ecx) = Old Priority (Vector)
mov eax, edx
shr eax, 4
movzx eax, _HalpVectorToIRQL[eax] ; (al) = OldIrql
;
; Test lock
;
; TEST_SPINLOCK ecx,<short slm30> ; NOTE - Macro expanded below:
test dword ptr [ecx], 1
nop ; On a P6 prior to stepping B1 (619), we
nop ; need these 5 NOPs to ensure that we
nop ; do not take a machine check exception.
nop ; The cost is just 1.5 clocks as the P6
nop ; just tosses the NOPs.
jnz short slm30
;
; Raise irql.
;
slm10: mov dword ptr APIC[LU_TPR], APIC_SYNCH_VECTOR
;
; Attempt to assert the lock
;
ACQUIRE_SPINLOCK ecx,<short slm20>
fstRET KeAcquireSpinLockRaiseToSynchMCE
;
; Lock is owned, spin till it looks free, then go get it
;
align dword
slm20: mov dword ptr APIC[LU_TPR], edx
align dword
slm30: SPIN_ON_SPINLOCK ecx,slm10
fstENDP KeAcquireSpinLockRaiseToSynchMCE
endif
PAGE
SUBTTL "Release Kernel Spin Lock"
;++
;
; VOID
; FASTCALL
; KeReleaseSpinLock (
; 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 a kernel spin lock.
; (dl) = NewIrql - New irql value to set.
;
; Return Value:
;
; None.
;
;--
align 16
cPublicFastCall KfReleaseSpinLock ,2
cPublicFpo 0,0
xor eax, eax
mov al, dl ; (eax) = new irql value
ifndef NT_UP
RELEASE_SPINLOCK ecx ; release spinlock
endif
xor ecx, ecx
mov cl, _HalpIRQLtoTPR[eax] ; get TPR value corresponding to IRQL
mov dword ptr APIC[LU_TPR], ecx
;
; We have to ensure that the requested priority is set before
; we return. The caller is counting on it.
;
mov eax, dword ptr APIC[LU_TPR]
if DBG
cmp ecx, eax ; Verify IRQL read back is same as
je short @f ; set value
int 3
@@:
endif
fstRET KfReleaseSpinLock
fstENDP KfReleaseSpinLock
;++
;
; KIRQL
; FASTCALL
; HalpAcquireHighLevelLock (
; IN PKSPIN_LOCK SpinLock
; )
;
; Routine Description:
;
; Acquires a spinlock with interrupts disabled.
;
; Arguments:
;
; (ecx) = SpinLock - Supplies a pointer to a kernel spin lock.
;
; Return Value:
;
; OldIrql (TOS+8) - pointer to place old irql.
;
;--
cPublicFastCall HalpAcquireHighLevelLock ,1
pushfd
pop eax
ahll10: cli
ACQUIRE_SPINLOCK ecx, ahll20
fstRET HalpAcquireHighLevelLock
ahll20:
push eax
popfd
SPIN_ON_SPINLOCK ecx, <ahll10>
fstENDP HalpAcquireHighLevelLock
;++
;
; VOID
; FASTCALL
; HalpReleaseHighLevelLock (
; 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 a kernel spin lock.
; (dl) = NewIrql - New irql value to set.
;
; Return Value:
;
; None.
;
;--
cPublicFastCall HalpReleaseHighLevelLock ,2
RELEASE_SPINLOCK ecx
push edx
popfd
fstRET HalpReleaseHighLevelLock
fstENDP HalpReleaseHighLevelLock
;++
;
; VOID
; FASTCALL
; ExAcquireFastMutex (
; IN PFAST_MUTEX FastMutex
; )
;
; Routine description:
;
; This function acquires ownership of the specified FastMutex.
;
; Arguments:
;
; (ecx) = FastMutex - Supplies a pointer to the fast mutex.
;
; Return Value:
;
; None.
;
;--
cPublicFastCall ExAcquireFastMutex,1
cPublicFpo 0,0
mov eax, dword ptr APIC[LU_TPR] ; (eax) = Old Priority (Vector)
if DBG
;
; Caller must already be at or below APC_LEVEL.
;
cmp eax, APC_VECTOR
jg short afm11 ; irql too high ==> fatal.
endif
mov dword ptr APIC[LU_TPR], APC_VECTOR ; Write New Priority to the TPR
LOCK_DEC dword ptr [ecx].FmCount ; Get count
jz short afm_ret ; The owner? Yes, Done
inc dword ptr [ecx].FmContention
cPublicFpo 0,2
push ecx
push eax
add ecx, FmEvent ; Wait on Event
stdCall _KeWaitForSingleObject,<ecx,WrExecutive,0,0,0>
pop eax ; (al) = OldTpr
pop ecx ; (ecx) = FAST_MUTEX
cPublicFpo 0,0
afm_ret:
mov byte ptr [ecx].FmOldIrql, al
;
; Use esp to track the owning thread for debugging purposes.
; !thread from kd will find the owning thread. Note that the
; owner isn't cleared on release, check if the mutex is owned
; first.
;
mov dword ptr [ecx].FmOwner, esp
fstRet ExAcquireFastMutex
if DBG
cPublicFpo 0,1
afm11: stdCall _KeBugCheckEx,<IRQL_NOT_GREATER_OR_EQUAL,ecx,eax,033h,0>
endif
fstENDP ExAcquireFastMutex
;++
;
; 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
if DBG
;
; Caller must already be at APC_LEVEL or have APCs blocked.
;
mov eax, dword ptr APIC[LU_TPR] ; (eax) = Old Priority (Vector)
cmp eax, APC_VECTOR
je short rfm04 ; irql is ok.
if 0
mov eax, PCR[PcPrcb]
mov eax, [eax].PbCurrentThread ; (eax) = Current Thread
cmp dword ptr [eax]+ThKernelApcDisable, 0
jne short rfm04 ; APCs disabled, this is ok
cmp dword ptr [eax]+ThTeb, 0
je short rfm04 ; No TEB ==> system thread, this is ok
test dword ptr [eax]+ThTeb, 080000000h
jnz short rfm04 ; TEB in system space, this is ok
endif
jmp short rfm20
rfm04:
endif
xor eax, eax
mov al, byte ptr [ecx].FmOldIrql ; (eax) = OldTpr
LOCK_ADD dword ptr [ecx].FmCount, 1 ; Remove our count
js short rfm05 ; if < 0, set event
jnz short rfm10 ; if != 0, don't set event
cPublicFpo 0,1
rfm05: add ecx, FmEvent
push eax ; save new tpr
stdCall _KeSetEventBoostPriority, <ecx, 0>
pop eax ; restore tpr
cPublicFpo 0,0
rfm10: mov dword ptr APIC[LU_TPR], eax
mov ecx, dword ptr APIC[LU_TPR]
if DBG
cmp eax, ecx ; Verify TPR is what was
je short @f ; written
int 3
@@:
endif
fstRet ExReleaseFastMutex
if DBG
cPublicFpo 0,1
rfm20: stdCall _KeBugCheckEx,<IRQL_NOT_GREATER_OR_EQUAL,ecx,eax,034h,0>
endif
fstENDP ExReleaseFastMutex
;++
;
; BOOLEAN
; FASTCALL
; ExTryToAcquireFastMutex (
; IN PFAST_MUTEX FastMutex
; )
;
; Routine description:
;
; This function acquires 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
if DBG
;
; Caller must already be at or below APC_LEVEL.
;
mov eax, dword ptr APIC[LU_TPR] ; (eax) = Old Priority (Vector)
cmp eax, APC_VECTOR
jg short tam11 ; irql too high ==> fatal.
endif
;
; Try to acquire.
;
cmp dword ptr [ecx].FmCount, 1 ; Busy?
jne short tam25 ; Yes, abort
mov eax, dword ptr APIC[LU_TPR] ; (eax) = Old Priority (Vector)
mov dword ptr APIC[LU_TPR], APC_VECTOR ; Write New Priority to the TPR
cPublicFpo 0,1
push eax ; Save Old TPR
mov edx, 0 ; Value to set
mov eax, 1 ; Value to compare against
LOCK_CMPXCHG dword ptr [ecx].FmCount, edx ; Attempt to acquire
jnz short tam20 ; got it?
cPublicFpo 0,0
pop edx ; (edx) = Old TPR
mov eax, 1 ; return TRUE
mov byte ptr [ecx].FmOldIrql, dl ; Store Old TPR
fstRet ExTryToAcquireFastMutex
tam20: pop ecx ; (ecx) = Old TPR
mov dword ptr APIC[LU_TPR], ecx
mov eax, dword ptr APIC[LU_TPR]
if DBG
cmp ecx, eax ; Verify TPR is what was
je short @f ; written
int 3
@@:
endif
tam25: xor eax, eax ; return FALSE
YIELD
fstRet ExTryToAcquireFastMutex ; all done
if DBG
cPublicFpo 0,1
tam11: stdCall _KeBugCheckEx,<IRQL_NOT_GREATER_OR_EQUAL,ecx,eax,033h,0>
endif
fstENDP ExTryToAcquireFastMutex
page ,132
subttl "Acquire Queued SpinLock Raise to Synch"
; compile time assert sizeof(KSPIN_LOCK_QUEUE) == 8
.errnz (LOCK_QUEUE_HEADER_SIZE - 8)
align 16
;++
;
; VOID
; KeAcquireInStackQueuedSpinLock (
; IN PKSPIN_LOCK SpinLock,
; IN PKLOCK_QUEUE_HANDLE LockHandle
; )
;
; VOID
; KeAcquireInStackQueuedSpinLockRaiseToSynch (
; IN PKSPIN_LOCK SpinLock,
; IN PKLOCK_QUEUE_HANDLE LockHandle
; )
;
; Routine Description:
;
; KeAcquireInStackQueuedSpinLock...
;
; The Kx versions use a LOCK_QUEUE_HANDLE structure rather than
; LOCK_QUEUE structures in the PRCB. Old IRQL is stored in the
; LOCK_QUEUE_HANDLE.
;
; Arguments:
;
; SpinLock (ecx) Address of Actual Lock.
; LockHandle (edx) Address of lock context.
;
; Return Value:
;
; None. Actually returns OldIrql because common code is used
; for all implementations.
;
;--
cPublicFastCall KeAcquireInStackQueuedSpinLockRaiseToSynch,2
cPublicFpo 0,0
ifdef NT_UP
; In the Uniprocessor case, just raise IRQL to SYNCH
mov eax, dword ptr APIC[LU_TPR] ; (eax) = Old Priority
shr eax, 4
mov al, byte ptr _HalpVectorToIRQL[eax] ; (al) = OldIrql
mov dword ptr APIC[LU_TPR], APIC_SYNCH_VECTOR
mov [edx].LqhOldIrql, al ; save old IRQL in lock handle
fstRET KeAcquireInStackQueuedSpinLockRaiseToSynch
else
; MP case, use KeAcquireInStackQueuedSpinLock to get the lock and raise
; to SYNCH asap afterwards.
call @KeAcquireInStackQueuedSpinLock@8
mov dword ptr APIC[LU_TPR], APIC_SYNCH_VECTOR
fstRET KeAcquireInStackQueuedSpinLockRaiseToSynch
endif
fstENDP KeAcquireInStackQueuedSpinLockRaiseToSynch
cPublicFastCall KeAcquireInStackQueuedSpinLock,2
cPublicFpo 0,0
; Raise IRQL to DISPATCH_LEVEL
mov eax, dword ptr APIC[LU_TPR] ; (eax) = Old Priority
shr eax, 4
mov al, byte ptr _HalpVectorToIRQL[eax] ; (al) = OldIrql
mov dword ptr APIC[LU_TPR], DPC_VECTOR ; raise to DISPATCH level
mov [edx].LqhOldIrql, al ; save old IRQL in lock handle
ifdef NT_UP
fstRET KeAcquireInStackQueuedSpinLock
else
; Save actual lock address in lock handle.
mov [edx].LqhLock, ecx
mov dword ptr [edx].LqhNext, 0
; ecx contains the address of the actual lock
; and edx the address of a queued lock structure.
cPublicFpo 0,1
mov eax, edx ; save Lock Queue entry address
if DBG
test ecx, LOCK_QUEUE_OWNER+LOCK_QUEUE_WAIT
jnz short iqsl98 ; jiff lock already held (or
; this proc already waiting).
endif
; Exchange the value of the lock with the address of this
; Lock Queue entry.
xchg [ecx], edx
cmp edx, 0 ; check if lock is held
jnz short iqsl40 ; jiff held
; lock has been acquired.
cPublicFpo 0,0
; note: the actual lock address is word aligned, we use
; the bottom two bits as indicators, bit 0 is LOCK_QUEUE_WAIT,
; bit 1 is LOCK_QUEUE_OWNER.
or ecx, LOCK_QUEUE_OWNER ; mark self as lock owner
mov [eax].LqLock, ecx
iqsl20:
fstRET KeAcquireInStackQueuedSpinLock
cPublicFpo 0,1
iqsl40:
; The lock is already held by another processor. Set the wait
; bit in this processor's Lock Queue entry, then set the next
; field in the Lock Queue entry of the last processor to attempt
; to acquire the lock (this is the address returned by the xchg
; above) to point to THIS processor's lock queue entry.
or ecx, LOCK_QUEUE_WAIT ; set waiting bit
mov [eax].LqLock, ecx
mov [edx].LqNext, eax ; set previous acquirer's
; next field.
; Wait.
@@:
test [eax].LqLock, LOCK_QUEUE_WAIT ; check if still waiting
jz short iqsl20 ; jif lock acquired
YIELD ; fire avoidance.
jmp short @b ; else, continue waiting
; Wait.
if DBG
cPublicFpo 0,1
iqsl98: stdCall _KeBugCheckEx,<SPIN_LOCK_ALREADY_OWNED,ecx,edx,0,0>
int 3 ; so stacktrace works
endif
endif
fstENDP KeAcquireInStackQueuedSpinLock
;++
;
; KIRQL
; KeAcquireQueuedSpinLockRaiseToSynch (
; IN KSPIN_LOCK_QUEUE_NUMBER Number
; )
;
; Routine Description:
;
; This function raises the current IRQL to DISPATCH/SYNCH level
; and acquires the specified queued spinlock.
;
; Arguments:
;
; Number (ecx) - Supplies the queued spinlock number.
;
; Return Value:
;
; The previous IRQL is returned as the function value.
;
;--
cPublicFastCall KeAcquireQueuedSpinLockRaiseToSynch,1
cPublicFpo 0,0
ifdef NT_UP
; In the Uniprocessor case, just raise IRQL to SYNCH
mov eax, dword ptr APIC[LU_TPR] ; (eax) = Old Priority
shr eax, 4
movzx eax, byte ptr _HalpVectorToIRQL[eax] ; (al) = OldIrql
mov dword ptr APIC[LU_TPR], APIC_SYNCH_VECTOR
fstRET KeAcquireQueuedSpinLockRaiseToSynch
else
; MP case, use KeAcquireQueuedSpinLock to get the lock and raise
; to SYNCH asap afterwards.
call @KeAcquireQueuedSpinLock@4
mov dword ptr APIC[LU_TPR], APIC_SYNCH_VECTOR
fstRET KeAcquireQueuedSpinLockRaiseToSynch
endif
fstENDP KeAcquireQueuedSpinLockRaiseToSynch
page ,132
subttl "Acquire Queued SpinLock"
;++
;
; KIRQL
; KeAcquireQueuedSpinLock (
; IN KSPIN_LOCK_QUEUE_NUMBER Number
; )
;
; Routine Description:
;
; This function raises the current IRQL to DISPATCH level
; and acquires the specified queued spinlock.
;
; Arguments:
;
; Number (ecx) - Supplies the queued spinlock number.
;
; Return Value:
;
; The previous IRQL is returned as the function value.
;
;--
cPublicFastCall KeAcquireQueuedSpinLock,1
cPublicFpo 0,0
; Get old priority (vector) from Local APIC's Task Priority
; Register and set the new priority.
mov eax, dword ptr APIC[LU_TPR] ; (eax) = Old Priority
shr eax, 4
movzx eax, byte ptr _HalpVectorToIRQL[eax] ; (al) = OldIrql
mov dword ptr APIC[LU_TPR], DPC_VECTOR ; raise to DISPATCH level
ifdef NT_UP
; in the Uniprocessor version all we do is raise IRQL.
fstRET KeAcquireQueuedSpinLock
else
; Get address of Lock Queue entry
mov edx, PCR[PcPrcb] ; get address of PRCB
lea edx, [edx+ecx*8].PbLockQueue ; get &PRCB->LockQueue[Number]
; Get address of the actual lock.
mov ecx, [edx].LqLock
aqsl10:
push eax ; save old IRQL
cPublicFpo 0,1
mov eax, edx ; save Lock Queue entry address
if DBG
test ecx, LOCK_QUEUE_OWNER+LOCK_QUEUE_WAIT
jnz short aqsl98 ; jiff lock already held (or
; this proc already waiting).
endif
; Exchange the value of the lock with the address of this
; Lock Queue entry.
xchg [ecx], edx
cmp edx, 0 ; check if lock is held
jnz short aqsl40 ; jiff held
; lock has been acquired.
cPublicFpo 0,0
; note: the actual lock address is word aligned, we use
; the bottom two bits as indicators, bit 0 is LOCK_QUEUE_WAIT,
; bit 1 is LOCK_QUEUE_OWNER.
or ecx, LOCK_QUEUE_OWNER ; mark self as lock owner
mov [eax].LqLock, ecx
aqsl20:
pop eax ; return old IRQL
fstRET KeAcquireQueuedSpinLock
cPublicFpo 0,1
aqsl40:
; The lock is already held by another processor. Set the wait
; bit in this processor's Lock Queue entry, then set the next
; field in the Lock Queue entry of the last processor to attempt
; to acquire the lock (this is the address returned by the xchg
; above) to point to THIS processor's lock queue entry.
or ecx, LOCK_QUEUE_WAIT ; set waiting bit
mov [eax].LqLock, ecx
mov [edx].LqNext, eax ; set previous acquirer's
; next field.
cPublicFpo 0,0
; Wait.
@@:
test [eax].LqLock, LOCK_QUEUE_WAIT ; check if still waiting
jz short aqsl20 ; jif lock acquired
YIELD ; fire avoidance.
jmp short @b ; else, continue waiting
if DBG
cPublicFpo 0,1
aqsl98: stdCall _KeBugCheckEx,<SPIN_LOCK_ALREADY_OWNED,ecx,edx,0,0>
int 3 ; so stacktrace works
endif
endif
fstENDP KeAcquireQueuedSpinLock
page ,132
subttl "Release Queued SpinLock"
;++
;
; VOID
; KeReleaseInStackQueuedSpinLock (
; IN PKLOCK_QUEUE_HANDLE LockHandle
; )
;
; Routine Description:
;
; This function releases a queued spinlock and lowers the IRQL to
; its previous value.
;
; This differs from KeReleaseQueuedSpinLock in that this version
; uses a caller supplied lock context where that one uses a
; predefined lock context in the processor's PRCB.
;
; This version sets up a compatible register context and uses
; KeReleaseQueuedSpinLock to do the actual work.
;
; Arguments:
;
; LockHandle (ecx) - Address of Lock Queue Handle structure.
;
; Return Value:
;
; None.
;
;--
cPublicFastCall KeReleaseInStackQueuedSpinLock,1
cPublicFpo 0,0
movzx edx, byte ptr [ecx].LqhOldIrql ; get old irql
ifndef NT_UP
lea eax, [ecx].LqhNext ; get address of lock struct
jmp short rqsl10 ; continue in common code
else
; Set the IO APIC's Task Priority Register to the value
; corresponding to the new IRQL.
movzx ecx, byte ptr _HalpIRQLtoTPR[edx]
mov dword ptr APIC[LU_TPR], ecx
; Ensure that the requested priority is set before returning,
; the caller is counting on it.
mov eax, dword ptr APIC[LU_TPR]
if DBG
cmp ecx, eax ; Verify IRQL read back is same as
je short @f ; set value
int 3
@@:
endif
fstRET KeReleaseInStackQueuedSpinLock
endif
fstENDP KeReleaseInStackQueuedSpinLock
;++
;
; VOID
; KeReleaseQueuedSpinLock (
; IN KSPIN_LOCK_QUEUE_NUMBER Number,
; IN KIRQL OldIrql
; )
;
; Routine Description:
;
; This function releases a queued spinlock and lowers the IRQL to
; its previous value.
;
; Arguments:
;
; Number (ecx) - Supplies the queued spinlock number.
; OldIrql (dl) - Supplies the IRQL value to lower to.
;
; Return Value:
;
; None.
;
;--
cPublicFastCall KeReleaseQueuedSpinLock,2
cPublicFpo 0,0
.errnz (LOCK_QUEUE_OWNER - 2) ; error if not bit 1 for btr
ifndef NT_UP
; Get address of Lock Queue entry
mov eax, PCR[PcPrcb] ; get address of PRCB
endif
movzx edx, dl ; Irql = 8 bits from edx
ifndef NT_UP
lea eax, [eax+ecx*8].PbLockQueue ; get &PRCB->LockQueue[Number]
rqsl10:
push ebx ; need another register
cPublicFpo 0,1
; Clear the lock field in the Lock Queue entry.
mov ebx, [eax].LqNext
mov ecx, [eax].LqLock
; Quick check: If Lock Queue entry's Next field is not NULL,
; there is another waiter. Don't bother with ANY atomic ops
; in this case.
;
; Note: test clears CF and sets ZF appropriately, the following
; btr sets CF appropriately for the owner check.
test ebx, ebx
; clear the "I am owner" bit in the Lock entry.
btr ecx, 1 ; clear owner bit.
if DBG
jnc short rqsl98 ; bugcheck if was not set
; tests CF
endif
mov [eax].LqLock, ecx ; clear lock bit in queue entry
jnz short rqsl40 ; jif another processor waits
; tests ZF
; ebx contains zero here which will be used to set the new owner NULL
push eax ; save &PRCB->LockQueue[Number]
cPublicFpo 0,2
; Use compare exchange to attempt to clear the actual lock.
; If there are still no processors waiting for the lock when
; the compare exchange happens, the old contents of the lock
; should be the address of this lock entry (eax).
lock cmpxchg [ecx], ebx ; store 0 if no waiters
pop eax ; restore lock queue address
cPublicFpo 0,1
jnz short rqsl60 ; jif store failed
; The lock has been released. Lower IRQL and return to caller.
endif
rqsl20:
; Set the IO APIC's Task Priority Register to the value
; corresponding to the new IRQL.
movzx ecx, byte ptr _HalpIRQLtoTPR[edx]
ifndef NT_UP
pop ebx ; restore ebx
cPublicFpo 0,0
endif
mov dword ptr APIC[LU_TPR], ecx
; Ensure that the requested priority is set before returning,
; the caller is counting on it.
mov eax, dword ptr APIC[LU_TPR]
if DBG
cmp ecx, eax ; Verify IRQL read back is same as
je short @f ; set value
int 3
@@:
endif
fstRET KeReleaseQueuedSpinLock
ifndef NT_UP
cPublicFpo 0,1
; Another processor is waiting on this lock. Hand the lock
; to that processor by getting the address of its LockQueue
; entry, turning ON its owner bit and OFF its wait bit.
rqsl40: xor [ebx].LqLock, (LOCK_QUEUE_OWNER+LOCK_QUEUE_WAIT)
; Done, the other processor now owns the lock, clear the next
; field in my LockQueue entry (to preserve the order for entering
; the queue again) and proceed to lower IRQL and return.
mov [eax].LqNext, 0
jmp short rqsl20
; We get here if another processor is attempting to acquire
; the lock but had not yet updated the next field in this
; processor's Queued Lock Next field. Wait for the next
; field to be updated.
rqsl60: mov ebx, [eax].LqNext
test ebx, ebx ; check if still 0
jnz short rqsl40 ; jif Next field now set.
YIELD ; wait a bit
jmp short rqsl60 ; continue waiting
if DBG
cPublicFpo 0,1
rqsl98: stdCall _KeBugCheckEx,<SPIN_LOCK_NOT_OWNED,ecx,eax,0,1>
int 3 ; so stacktrace works
endif
endif
fstENDP KeReleaseQueuedSpinLock
page ,132
subttl "Try to Acquire Queued SpinLock"
;++
;
; LOGICAL
; KeTryToAcquireQueuedSpinLock (
; IN KSPIN_LOCK_QUEUE_NUMBER Number,
; OUT PKIRQL OldIrql
; )
;
; LOGICAL
; KeTryToAcquireQueuedSpinLockRaiseToSynch (
; IN KSPIN_LOCK_QUEUE_NUMBER Number,
; OUT PKIRQL OldIrql
; )
;
; Routine Description:
;
; This function raises the current IRQL to DISPATCH/SYNCH level
; and attempts to acquire the specified queued spinlock. If the
; spinlock is already owned by another thread, IRQL is restored
; to its previous value and FALSE is returned.
;
; Arguments:
;
; Number (ecx) - Supplies the queued spinlock number.
; OldIrql (edx) - A pointer to the variable to receive the old
; IRQL.
;
; Return Value:
;
; TRUE if the lock was acquired, FALSE otherwise.
; N.B. ZF is set if FALSE returned, clear otherwise.
;
;--
align 16
cPublicFastCall KeTryToAcquireQueuedSpinLockRaiseToSynch,2
cPublicFpo 0,0
push APIC_SYNCH_VECTOR ; raise to SYNCH
jmp short taqsl10 ; continue in common code
fstENDP KeTryToAcquireQueuedSpinLockRaiseToSynch
cPublicFastCall KeTryToAcquireQueuedSpinLock,2
cPublicFpo 0,0
push DPC_VECTOR ; raise to DPC level
; Attempt to get the lock with interrupts disabled, raising
; the priority in the interrupt controller only if acquisition
; is successful.
taqsl10:
ifndef NT_UP
push edx ; save address of OldIrql
pushfd ; save interrupt state
cPublicFpo 0,3
; Get address of Lock Queue entry
cli
mov edx, PCR[PcPrcb] ; get address of PRCB
lea edx, [edx+ecx*8].PbLockQueue ; get &PRCB->LockQueue[Number]
; Get address of the actual lock.
mov ecx, [edx].LqLock
if DBG
test ecx, LOCK_QUEUE_OWNER+LOCK_QUEUE_WAIT
jnz short taqsl98 ; jiff lock already held (or
; this proc already waiting).
endif
; quick test, get out if already taken
cmp dword ptr [ecx], 0 ; check if already taken
jnz short taqsl60 ; jif already taken
xor eax, eax ; comparison value (not locked)
; Store the Lock Queue entry address in the lock ONLY if the
; current lock value is 0.
lock cmpxchg [ecx], edx
jnz short taqsl60
; Lock has been acquired.
; note: the actual lock address will be word aligned, we use
; the bottom two bits as indicators, bit 0 is LOCK_QUEUE_WAIT,
; bit 1 is LOCK_QUEUE_OWNER.
or ecx, LOCK_QUEUE_OWNER ; mark self as lock owner
mov [edx].LqLock, ecx
mov eax, [esp+8] ; get new IRQL
mov edx, [esp+4] ; get addr to save OldIrql
else
mov eax, [esp] ; get new IRQL
endif
; Raise IRQL and return success.
; Get old priority (vector) from Local APIC's Task Priority
; Register and set the new priority.
mov ecx, dword ptr APIC[LU_TPR] ; (ecx) = Old Priority
mov dword ptr APIC[LU_TPR], eax ; Set New Priority
ifndef NT_UP
popfd ; restore interrupt state
add esp, 8 ; free locals
else
add esp, 4 ; free local
endif
cPublicFpo 0,0
shr ecx, 4
movzx eax, _HalpVectorToIRQL[ecx] ; (al) = OldIrql
mov [edx], al ; save OldIrql
xor eax, eax ; return TRUE
or eax, 1
fstRET KeTryToAcquireQueuedSpinLock
ifndef NT_UP
taqsl60:
; The lock is already held by another processor. Indicate
; failure to the caller.
popfd ; restore interrupt state
add esp, 8 ; free locals
xor eax, eax ; return FALSE
fstRET KeTryToAcquireQueuedSpinLock
if DBG
cPublicFpo 0,2
taqsl98: stdCall _KeBugCheckEx,<SPIN_LOCK_ALREADY_OWNED,ecx,edx,0,0>
int 3 ; so stacktrace works
endif
endif
fstENDP KeTryToAcquireQueuedSpinLock
_TEXT ends
ENDIF ; NT_INST
end