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Diffstat (limited to 'private/ntos/nthals/halncr/i386/ncrcatlk.asm')
| -rw-r--r-- | private/ntos/nthals/halncr/i386/ncrcatlk.asm | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/private/ntos/nthals/halncr/i386/ncrcatlk.asm b/private/ntos/nthals/halncr/i386/ncrcatlk.asm new file mode 100644 index 000000000..b720a4142 --- /dev/null +++ b/private/ntos/nthals/halncr/i386/ncrcatlk.asm @@ -0,0 +1,120 @@ + title "CAT Bus Lock Routines" +;++ +; +; Module Name: +; +; ncrcatlk.asm +; +; Abstract: +; +; Procedures necessary to lock CAT bus. +; +; Author: +; +; Rick Ulmer (rick.ulmer@columbiasc.ncr.com) 29 Apr 1993 +; +; Revision History: +; +; +;-- + +.386p + .xlist +include hal386.inc +include callconv.inc ; calling convention macros +include mac386.inc + .list + + extrn _HalpCatBusLock:DWORD + +_DATA SEGMENT DWORD USE32 PUBLIC 'DATA' +; +; Hold the value of the eflags register before a CAT bus spinlock is +; acquired (used in HalpAcquire/ReleaseCatBusSpinLock(). +; +_HalpCatBusFlags dd 0 + +_DATA ends + + subttl "HalpAcquireCatBusSpinLock" +_TEXT SEGMENT DWORD USE32 PUBLIC 'CODE' + ASSUME CS:FLAT, DS:FLAT, ES:FLAT, SS:NOTHING, FS:NOTHING, GS:NOTHING + +;++ +; +; Routine Description: +; +; Acquires a spinlock to access the CAT bus. The CAT bus is +; accessed at different irql levels, so to be safe, we 'cli'. +; We could replace that to raise irql to PROFILE_LEVEL, but that's +; a lot of code. +; +; Arguments: +; +; None +; +; Return Value: +; +; Interrupt is disabled. +; Irql level not affected. +; Flags saved in _HalpCatBusLockFlags. +;-- + +cPublicProc _HalpAcquireCatBusSpinLock ,0 + push eax + + align 4 +HArsl01: + pushfd + cli + lea eax, _HalpCatBusLock + ACQUIRE_SPINLOCK eax, HArsl90 + pop _HalpCatBusFlags ; save flags for release S.L. + pop eax + stdRET _HalpAcquireCatBusSpinLock + + align 4 +HArsl90: + popfd + SPIN_ON_SPINLOCK eax, <HArsl01> + +stdENDP _HalpAcquireCatBusSpinLock + + + subttl "HalpReleaseCatBusSpinLock" +;++ +; +; Routine Description: +; +; Release spinlock, and restore flags to the state it was before +; acquiring the spinlock. +; +; Arguments: +; +; None +; +; Return Value: +; +; Interrupts restored to their state before acquiring spinlock. +; Irql level not affected. +; +;-- + +cPublicProc _HalpReleaseCatBusSpinLock ,0 + push eax + ; + ; restore eflags as it was before acquiring spinlock. Put it on + ; stack before releasing spinlock (so other cpus cannot overwrite + ; it with their own eflags). + ; + push _HalpCatBusFlags ; old eflags on stack. + lea eax, _HalpCatBusLock + RELEASE_SPINLOCK eax + popfd ; restore eflags. + pop eax + stdRET _HalpReleaseCatBusSpinLock +stdENDP _HalpReleaseCatBusSpinLock + +_TEXT ends + + end |