boot3/Internal/Asm/DiskCachePriv.a

;
;	File:		DiskCachePriv.a
;
;	Contains:	Private equates for the RAM cache
;
;	Written by:	Kenny SC. Tung
;
;	Copyright:	<09> 1985-1992 by Apple Computer, Inc., all rights reserved.
;
;	Change History (most recent first):
;
;		 <2>	  3/3/92	kc		Remove ForROM code because we now use the new cache.
;		<12>	 12/3/91	KST		Added some documentation.
;		<11>	 8/21/91	JSM		Clean up header.
;		<10>	  7/8/91	JSM		Remove obsolete SysVers conditionals.
;		 <9>	 1/30/91	gbm		sab, #38: Change the <20>already including this file<6C> variable to
;									all uppercase (for security reasons)
;		 <8>	  1/2/91	KST		Adding some new defs.
;		 <7>	10/29/90	KST		Set minimum number of buckets of the device hash table to be 16.
;		 <6>	 8/27/90	KST		Move some equates to fsPrivate.a
;		 <5>	  8/7/90	KST		Changed number of file queues from 40 to 50. And made this file
;									works for ROM build.
;		 <4>	  8/6/90	KST		Major rewrite for 7.0. Changing and adding lots of new equates.
;		 <3>	 7/26/90	gbm		can't use dirtyBit... changing it to cacheDirtyBit
;	   <1.0>	 3/20/89	CCH		Adding to EASE from System build.
;				11/20/87	JB		Added cache var 'CacheMinZn' which functionally replaces the
;									constant 'minApplZone'. Parameter is now settable via cache
;									control trap.
;				 9/14/87	JB		Changed minApplZone to 384k to allow more application space on 1
;									megabyte systems. (S272)
;				 12/2/86	LAK		Added equate for CacheRegs (regs saved over cache adjust).
;									Changed TFSDebug to new CacheDebug message with message.
;				  8/4/86	DLD		Added macro definiton for _AssumeEq, _TFSDebug, and and
;									TFSDebug.
;				 7/23/86	DLD		Converted source to MPW.
;				 12/4/85	LAK		Added global age field, and age field to cache buffer headers.
;									Added FHBufMax, FHAttrib, FHExtra, FHFlType, FHParDID, FHRWIPMax
;									fields to file queue headers for better cache control, and to
;									allow writing of blocks belonging to a closed file. Added
;									CacheCom, noRWIPBit equates for external control of cache. Moved
;									CacheVars, CacheCom, noRWIPBit equates to TFSEQU.
;				11/29/85	LAK		New today.
;

	IF &TYPE('__INCLUDINGDISKCACHEPRIV__') = 'UNDEFINED' THEN
__INCLUDINGDISKCACHEPRIV__	SET	1

		if &type('ktDebugCache') = 'UNDEFINED' then
ktDebugCache	equ		0
		endif

;_______________________________________;
;
; MACRO definitions
;_______________________________________;


			BLANKS		ON
			STRING		ASIS

			MACRO						; replace a jump vector
			InstJV
			PEA 	&Syslst[1]
			MOVE.L	(SP)+,&Syslst[2]
			ENDM

CacheRegs	REG		D0-D7/A0-A2/A4-A6	;<02Dec86> save all but A3
AllRegs		REG		D0-D7/A0-A6			;<02Dec86> save all
minCache	EQU		$8000				;<02Dec86> use 32K min cache
minApplZone	EQU		$60000				;<14Sep87> use 384K min appl zone
;_______________________________________;
;
; Additional global equates
;_______________________________________;

FKeepOK 	EQU 	$90E				; 'OK' when FKeepIn is valid
FKeepIn 	EQU 	$90C				; positive when Keeper is installed
SwitchVars	EQU 	$282				; positive when Switcher is installed

CacheConfig EQU 	$20A				; size configuration byte
CacheEnable EQU 	$20B				; bit 5=1 when enabled

FileQHdr	EQU 	SysVolCPtr			; use old 2-block vol cache for
										;  cache queue headers
FreeQHdr	EQU 	SysBMCPtr			; use old bitmap cache for free queue
;_______________________________________;
;
; Cache Locals Definitions ($394)
;_______________________________________;

CacheVCnt		EQU 	8					; 8 cache vectors to replace

SegVectSave		EQU 	0					; (long) previous SegLoader vector
OldBufPtr		EQU 	4					; (long) set to pre-cache value of BufPtr
NewBufPtr		EQU 	8					; (long) set to bottom of cache
BufStart		EQU 	$C					; (long) 
CBHdrStart		EQU		$10					; (long) <20Apr90>
TotalBufN		EQU		$14					; (word) <20Apr90>
CurConfig		EQU 	$16 				; (byte) equal to CacheConfig, last adjust
CurEnable		EQU 	$17 				; (byte) $FF if enabled, $00 otherwise
CacheByteLim	EQU		$18 				; (long) bytesize max of requests to cache
CacheAge		EQU 	$1C 				; (long) starts at -1, counts down
CacheMinZn		EQU		$20					; (long) min application zone size		<20Nov87>

INITSegVect		EQU 	$24					; (long)
CacheIOBlk		EQU		$28					; (long) ptr to I/O blk used to sync with fs
CacheRoutine	EQU		$2C					; (long) routine to call after sync'ing
SavedHook		EQU		$30					; (long) saved ExtFS hook

LcDevHTPtr		EQU		$34					; (long) device hash table ptr			<24May90>
LcReserved1		EQU		$38					; (byte) TrashVBlks counter (called 3 times)
LcReserved2		EQU		$39					; (byte) not used 
LcGBinCache		EQU		$3A					; (word) set if buffer is not newly allocated,
											; ie., found in the cache. Used by cacheRdIP
LcGBinFQueue	EQU		$3A					; (byte) set if the block is found in file queue
LcGBinDHTable	EQU		$3B					; (byte) set if the block is found in free queue
LcXCacheKey		EQU 	$3C 				; (long) translation cache key	(buffer)
LcXCacheData	EQU 	$40 				; (long) translation cache data (header)
LcFreeMemSize	EQU		$44					; (word) free memory above OldBufPtr
CacheLclLen		EQU 	LcFreeMemSize+2		; end of locals

; The story w.r.t. BufPtr, NewBufPtr, and OldBufPtr is as follows:
;
; (1)	OldBufPtr <20> NewBufPtr <20> BufPtr, always.
; (2)	OldBufPtr - NewBufPtr = buffer space currently owned by the cache.
; (3)	If NewBufPtr = BufPtr, cache space is at bottom of buffer and may be
;		 adjusted (if neither Switcher nor FinderKeeper are installed).
; (4)	OldBufPtr, NewBufPtr are initialized to BufPtr when the cache is
;		 installed.  NewBufPtr is then lowered by the amount specified
;		 in parameter RAM at the first launch.

FLink		EQU 	0					; generic queue forward link offset
BLink		EQU 	4					; generic queue backward link offset
QCount		EQU 	8					; generic queue element count (hdr only)

; File Queue Header (top cache data structure).
;
; This is the queue header for all the file headers.

FQHFlink	EQU 	0					; (long) CQ forward link pointer
FQHBlink	EQU 	4					; (long) CQ backward link pointer
FQHFileCnt	EQU 	8					; (word) number of file headers
FQHExtra	EQU 	10					; (word) extra

FQHlength	EQU 	12					; length of FQH

fileHdrCnt	EQU 	50					; support up to 40 files for now
										; try 50 for now
; Free Queue Header (free blocks).
;
; The Free Block Queue is where trashed blocks go (and where all
; blocks are initially put).  These blocks are recycled before any
; other blocks.

FreeQFlink	EQU 	0					; (long) free queue forward link
FreeQBlink	EQU 	4					; (long) free queue backward link
FreeQBufCnt EQU 	8					; (word) free queue buffer count
TotalBufCnt EQU 	10					; (word) total number of buffers in cache
FreeQHlen	EQU 	12					; length of FQH

; File Header (one per file fork with blocks cached).
;
; There is also one queue per volume with volume blocks cached. For TFS
; volumes, only the MDB and volume map blocks would be found in the volume
; queue.  For MDS volumes, directory blocks would also go into the volume
; queue.

FHFlink 	EQU 	0					; (long) File Queue forward link
FHBlink 	EQU 	4					; (long) File Queue backward link
FHMQHFlink	EQU 	8					; (long) Cache Buffer Queue forward link
FHMQHBlink	EQU 	12					; (long) Cache Buffer Queue backward link
FHBufCnt	EQU 	16					; (word) cache buffer count
FHBufMax	EQU 	18					; (word) max buffer cnt for this file (not yet used)
FHFlags 	EQU 	20					; (byte) flags
noFlushBit	EQU 	7					;  1=avoid intermediate flushes
mruSrchBit	EQU 	6					;  1=use mru order for GetBlock search
fqDirtyBit	EQU 	5					;  1=a buffer in the FILE queue is dirty		<25Apr90>

FHFkType	EQU 	21					; (byte) $00 = data fork (or vol blk)
										;		 $FF = resource fork
FHAttrib	EQU 	22					; (byte) copied from attributes (used for tags)
FHExtra 	EQU 	23					; (byte) reserved for future use
FHFlType	EQU 	24					; (long) file type (TFS files) for HD20 file tags
FHVCBPtr	EQU 	28					; (long) VCB pointer (0 if free)			<30May90>
FHDQHFLink	EQU 	32					; (long) Disk Queue forward link			<30May90>
FHDQHBLink	EQU 	36					; (long) Disk Queue backward link			<30May90>
FHFlNum 	EQU 	40					; (long) file number (0 for vol blks)		<30May90>
FHParDID	EQU 	44					; (long) parent Dir ID (TFS files) for HD20 file tags
FHlength	EQU 	48					; length of File Header (HT = 256-48=208/8=26 buckets)

; File Header as MRU Queue Header

MQHFlink	EQU 	0					; (long) Cache Buffer Queue forward link
MQHBlink	EQU 	4					; (long) Cache Buffer Queue backward link
MQHBufCnt	EQU 	8					; (word) cache buffer count
MQHBufMax	EQU 	10					; (word) max buffer cnt for this file (not yet used)
MQHFlags	EQU 	12					; (byte) flags
MQHFkType	EQU 	13					; (byte) $00 = data fork (or vol blk)
										;		 $FF = resource fork
MQHAttrib	EQU 	14					; (byte) copied from attributes (used for tags)
MQHExtra	EQU 	15					; (byte) reserved for future use
MQHFlType	EQU 	16					; (long) file type (TFS files) for HD20 file tags
MQHVCBPtr	EQU 	20					; (long) VCB pointer (0 if free)

MQHDQHFLink EQU 	24					; (long) Disk Queue forward link
MQHDQHBLink EQU 	28					; (long) Disk Queue backward link
MQHFlNum	EQU 	32					; (long) file number (0 for vol blks)
MQHParDID	EQU 	36					; (long) parent Dir ID (TFS files) for HD20 file tags
;MQHashTbl	EQU 	40					; (long) hash table start				<12Jun90>

; File Header as File-ordered Queue Header (used to be Disk-ordered, ergo the 'D')

DQHMQHFlink EQU 	-24 				; (long) Cache Buffer Queue forward link
DQHMQHBlink EQU 	-20 				; (long) Cache Buffer Queue backward link
DQHBufCnt	EQU 	-16					; (word) cache buffer count
DQHBufMax	EQU 	-14					; (word) max buffer cnt for this file (not yet used)
DQHFlags	EQU 	-12					; (byte) flags
DQHFkType	EQU 	-11					; (byte) $00 = data fork (or vol blk)
										;		 $FF = resource fork
DQHAttrib	EQU 	-10					; (byte) copied from attributes (used for tags)
DQHExtra	EQU 	-9					; (byte) reserved for future use
DQHFlType	EQU 	-8					; (long) file type (TFS files) for HD20 file tags
DQHVCBPtr	EQU 	-4					; (long) VCB pointer (0 if free)
DQHFLink	EQU 	0					; (long) Disk Queue forward link
DQHBLink	EQU 	4					; (long) Disk Queue backward link
DQHFlNum	EQU 	8					; (long) file number (0 for vol blks)
DQHParDID	EQU 	12					; (long) parent Dir ID (TFS files) for HD20 file tags
;DQHashTbl	EQU 	16					; (long) hash table start				<12Jun90>


; Cache Block Header (one per cache block).
;
; Since the File Cache Header contains VCB, File Number, and fork
; type information, this is omitted for the cache block header.
; This may need to be expanded for multiblock r/w support.

; MRU-ordered Cache Block Header

MCBFlink	EQU 	0					; (long) Cache Buffer Queue forward link
MCBBlink	EQU 	4					; (long) Cache Buffer Queue backward link

MCBHashqFlink	EQU 	8				; (long) hash queue forword  link	<30May90>
MCBHashqBlink	EQU 	12				; (long) hash queue backword link	<30May90>

MCBFlags	EQU 	16					; (byte) flags
MCBExtra	EQU 	17					; (byte) extra (not used)
MCBFkType	EQU 	MCBExtra			; (byte) resource type				<11Jun90>
MCBRefNum	EQU 	18					; (word) last refnum used (debug use only?)	=>cbHqVRfn
MCBAge		EQU 	20					; (long) used for aging this block			=>cbHqDevNum
MCBDQFlink	EQU 	24					; (long) CBQ flink, in file order
MCBDQBlink	EQU 	28					; (long) CBQ blink, in file order
MCBDBlk 	EQU 	32					; (long) disk blk num						=>cbHqDevBlk
MCBFlBlk	EQU 	36					; (long) file blk num (=MCBDBlk for volblks)=>cbHqFilBlk
MCBFQPtr	EQU 	40					; (long) ptr to queue header
MCBFileNum	EQU		44					; (long) file number used by hash<11Jun90>	=>cbHqFilNum
MCBDataPtr	EQU 	48					; (long) pointer to data
MCBHLength	EQU 	52					; length of cache block header	<30May90>

cacheDirtyBit	EQU 	7				; ...buffer dirty flag
inuseBit		EQU 	6				; ...buffer in use flag
emptyBit		EQU 	5				; ...buffer is empty

DCBFlags	EQU 	-8					; (byte) flags
DCBExtra	EQU 	-7					; (byte) extra
DCBRefNum	EQU 	-6					; (word) last refnum used
DCDAge		EQU 	-4					; (long) used for aging this block
DCBFlink	EQU 	0					; (long) CBQ flink, in file order
DCBBlink	EQU 	4					; (long) CBQ blink, in file order
DCBDBlk 	EQU 	8					; (long) disk blk num
DCBFlBlk	EQU 	12					; (long) file blk num (=MCBDBlk for vol blks)
DCBFQPtr	EQU 	16					; (long) ptr to queue header
DCBFileNum	EQU		20					; (long) file number				<11Jun90>
DCBData 	EQU 	24					; start of data (or pointer)		<30May90>
										; fortunately, this is not used		<30May90>


			IF &Type('CacheDebug')='Undefined' THEN
CacheDebug	EQU 	0					; default debug code out
			ENDIF

;			MACRO			
;			_AssumeEq
;			IF	&EVAL(&SysList[1]) <> &EVAL(&SysList[2]) THEN
;				ERR		   ; Invalid statement - will cause error
;			ENDIF
;			ENDM

			MACRO
			_CacheDebug	&msg 				
 			IF		CacheDebug THEN
			PEA		&msg			; pass string255
			DC.W	$ABFF			; invoke Macsbug
			ENDIF
			ENDM			

			MACRO
			_CodeCheck 				
 			IF		CacheDebug THEN
			DC.W	$A9FF			; invoke Macsbug
			ENDIF
			ENDM			

Byteto32K		EQU		15			; convert to 32K multiple			<8>
kMinBootSize	EQU		16*1024		; at least 16K to boot				<8>
n32K			EQU		32*1024		; 32K  constant						<8>
n256K			EQU		256*1024	; 256K constant						<8>

log2Bsize		EQU		9			; log2 of 512 when BufSiz = 512		<20Apr90>
kMinCacheSize	EQU		$8000		; current minimum is 32K if DiskCache is not enabled on 7.0


;; hash table structure:
htKeyMask	EQU		0				; (word) key mask (# of buckets - 1)
htCount		EQU		2				; (word) # of elements in the hash table
htReserved	EQU		4				; (long) unused (# of buckets for debugging only)
htStart		EQU		8				; table starts

htEntrysize	EQU		8				; each entry is 8 bytes
htEntryLog2	EQU		3				; log 2 of htEntrysize

DevHTsize	EQU		3				; log2 of device hash table size (= bufcount/8)
maxDHTnum	EQU		512				; max = 512 buckets for DHT
minDHTnum	EQU		16				; min = 16  buckets for DHT

SaveinHash	EQU		'haSh'			; flag to keep buffer in DHT
fromWriteIP	EQU		'WrIP'			; called from writeIP

;; <20><> The usage of MCBAge: MCBDevNum = cbHqDevNum = MCBAge.					-- <KSCT #12>
;; When a buffer is in the file queue, MCBAge = age stamp,
;; When a buffer is in the free queue and is empty, MCBDevNum = MCBAge = 0,
;; When a buffer is in the free queue but is not empty, MCBDevNum = MCBAge = Vol RefNum.
;; In the last case, the buffer is also added in the hash table.

MCBDevNum	EQU 	MCBAge			; (word) device number (was MCBAge)
MCBHashKey	EQU 	MCBAge+2		; (word) bucket number (for debugging)

;; Block header points at hashqFlink on the hash queue:
cbHqVRfn	EQU		MCBRefNum	- MCBHashqFlink		; volume refnum
cbHqDevBlk	EQU		MCBDBlk		- MCBHashqFlink		; dev. block
cbHqFilBlk	EQU		MCBFlBlk	- MCBHashqFlink		; file block
cbHqFilNum	EQU		MCBFileNum	- MCBHashqFlink		; file number
cbHqDevNum	EQU		MCBDevNum	- MCBHashqFlink		; MCBage


	ENDIF					; ...already included