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Diffstat (limited to 'private/ntos/nthals/halppc/ppc/pxmisc.s')
| -rw-r--r-- | private/ntos/nthals/halppc/ppc/pxmisc.s | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/private/ntos/nthals/halppc/ppc/pxmisc.s b/private/ntos/nthals/halppc/ppc/pxmisc.s new file mode 100644 index 000000000..f8375ed2e --- /dev/null +++ b/private/ntos/nthals/halppc/ppc/pxmisc.s @@ -0,0 +1,159 @@ +//++ +// +// Copyright (c) 1995 IBM Corporation +// +// Module Name: +// +// pxmisc.s +// +// Abstract: +// +// Home for a small number of miscellaneous routines that need to +// be in assemblu code. +// +// Author: +// +// Peter L. Johnston (plj@vnet.ibm.com) August 1995 +// +// Environment: +// +// Kernel mode only. +// +// Revision History: +// +//-- + +#include "kxppc.h" + +#define LOCK_RETRY (64*1024*1024) + + .data + .globl HalpDisplayLock +HalpDisplayLock: + .long 0 + + +//++ +// +// VOID +// HalpAcquireDisplayLock( +// VOID +// ); +// +// Routine Description: +// +// Acquire a spinlock to ensure only processor is writing to the +// display (via HalDisplayString) at a time. +// +// If the attempt to acquire the lock fails after LOCK_RETRY attempts, +// just TAKE it on the assumption that the other processor is dead. +// +// Arguments: +// +// None. +// +// Return Value: +// +// None. +// +//-- + + LEAF_ENTRY(HalpAcquireDisplayLock) + + lwz r.3, [toc]HalpDisplayLock(r.toc) // get address of lock + LWI(r.4,LOCK_RETRY) // get retry count + mtctr r.4 // set loop count + li r.5, 1 // lock value + +getlk: lwarx r.4, 0, r.3 // get lock value + cmpwi r.4, 0 // already taken? + bne waitlk + stwcx. r.5, 0, r.3 // set locked + beqlr // return if store + // succeeded. +waitlk: lwz r.4, 0(r.3) // wait for lock to + // become 0. + bdz failed // jif retry limit + // exceeded. + cmpwi r.4, 0 + beq getlk // try again. + b waitlk // continue wait + +failed: stw r.5, 0(r.3) + + LEAF_EXIT(HalpAcquireDisplayLock) + +//++ +// +// VOID +// HalpReleaseDisplayLock( +// VOID +// ); +// +// Routine Description: +// +// Release the lock acquired by HalpAcquireDisplayLock. +// +// Arguments: +// +// None. +// +// Return Value: +// +// None. +// +//-- + + LEAF_ENTRY(HalpReleaseDisplayLock) + + lwz r.3, [toc]HalpDisplayLock(r.toc) // get address of lock + li r.0, 0 + stw r.0, 0(r.3) // release it + + LEAF_EXIT(HalpReleaseDisplayLock) + +//++ +// +// ULONG +// HalpGetPhysicalProcessorNumber( +// VOID +// ); +// +// Routine Description: +// +// Returns the number of this physical processor. +// +// Arguments: +// +// None. +// +// Return Value: +// +// Processor Number. +// +//-- + + LEAF_ENTRY(HalpGetPhysicalProcessorNumber) + +#if defined(_MP_PPC_) + + mfpvr r.0 // if 604 (or derivative) + rlwinm r.0, r.0, 16, 0xffff // get processor number + cmpwi cr.0, r.0, 4 // from SPR 1023 (PIR). + cmpwi cr.1, r.0, 9 // + + beq cr.0, type604 + bne cr.1, nota604 + +type604: + + mfspr r.3, 1023 // read 604 PIR register + blr + +nota604: + +#endif + + li r.3, 0 // fake it + + LEAF_EXIT(HalpGetPhysicalProcessorNumber) |