sys7.1-doc-wip/Internal/Asm/DiskCachePriv.a
2019-07-27 22:37:48 +08:00

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;
; File: DiskCachePriv.a
;
; Contains: Private equates for the RAM cache
;
; Written by: Kenny SC. Tung
;
; Copyright: © 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 already including this file 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 ≥ NewBufPtr ≥ 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
;; •• 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