NT4/private/ntos/nthals/halr98mp/mips/j4cache.s
2020-09-30 17:12:29 +02:00

1057 lines
34 KiB
ArmAsm

// "@(#) NEC j4cache.s 1.5 94/12/06 10:46:13"
// TITLE("Cache Flush")
//++
//
// Copyright (c) 1991-1994 Microsoft Corporation
//
// Module Name:
//
// j4cache.s
//
// Abstract:
//
// This module implements the code necessary for cache operations on
// a MIPS R4000.
//
//--
#include "halmips.h"
/*
* Original source: Build Number 1.612
*
* Modify for R98(MIPS/R4400)
*
***********************************************************************
*
* S001 94.08/22 T.Samezima on SNES
*
* Add define _DUO_
*
* K001 94/10/11 N.Kugimoto
* Fix 807 Base
* K002 94/12/06 N.Kugimoto
* Fix Mem32
*/
#define _DUO_ // S001
//
// Define cache operations constants.
//
#define COLOR_BITS (7 << PAGE_SHIFT) // color bit (R4000 - 8kb cache)
#define COLOR_MASK (0x7fff) // color mask (R4000 - 8kb cache)
#define FLUSH_BASE 0xfffe0000 // flush base address
#define PROTECTION_BITS ((1 << ENTRYLO_V) | (1 << ENTRYLO_D)) //
SBTTL("Change Color Page")
//++
//
// VOID
// HalChangeColorPage (
// IN PVOID NewColor,
// IN PVOID OldColor,
// IN ULONG PageFrame
// )
//
// Routine Description:
//
// This function changes the color of a page if the old and new colors
// do not match.
//
// The algorithm used to change colors for a page is as follows:
//
// 1. Purge (hit/invalidate) the page from the instruction cache
// using the old color.
//
// 2. Purge (hit/invalidate) the page from the data cache using
// the old color.
//
// Arguments:
//
// NewColor (a0) - Supplies the page aligned virtual address of the
// new color of the page to change.
//
// OldColor (a1) - Supplies the page aligned virtual address of the
// old color of the page to change.
//
// PageFrame (a2) - Supplies the page frame number of the page that
// is changed.
//
// Return Value:
//
// None.
//
//--
.struct 0
.space 3 * 4 // fill
CpRa: .space 4 // saved return address
CpFrameLength: // length of stack frame
CpA0: .space 4 // (a0)
CpA1: .space 4 // (a1)
CpA2: .space 4 // (a2)
CpA3: .space 4 // (a3)
NESTED_ENTRY(HalChangeColorPage, CpFrameLength, zero)
subu sp,sp,CpFrameLength // allocate stack frame
sw ra,CpRa(sp) // save return address
PROLOGUE_END
and a0,a0,COLOR_BITS // isolate new color bits
and a1,a1,COLOR_BITS // isolate old color bits
beq a0,a1,10f // if eq, colors match
sw a1,CpA1(sp) // save old color bits
sw a2,CpA2(sp) // save page frame
//
// Purge the instruction cache using the old page color.
//
move a0,a1 // set color value
move a1,a2 // set page frame number
li a2,PAGE_SIZE // set length of purge
jal HalPurgeIcachePage // purge instruction cache page
//
// Flush the data cache using the old page color.
//
lw a0,CpA1(sp) // get old color bits
lw a1,CpA2(sp) // get page frame number
li a2,PAGE_SIZE // set length of purge
jal HalFlushDcachePage // purge data cache page
10: lw ra,CpRa(sp) // get return address
addu sp,sp,CpFrameLength // deallocate stack frame
j ra // return
.end HalChangeColorPage
SBTTL("Flush Data Cache Page")
//++
//
// VOID
// HalFlushDcachePage (
// IN PVOID Color,
// IN ULONG PageFrame,
// IN ULONG Length
// )
//
// Routine Description:
//
// This function flushes (hit/writeback/invalidate) up to a page of data
// from the data cache.
//
// Arguments:
//
// Color (a0) - Supplies the starting virtual address and color of the
// data that is flushed.
//
// PageFrame (a1) - Supplies the page frame number of the page that
// is flushed.
//
// Length (a2) - Supplies the length of the region in the page that is
// flushed.
//
// Return Value:
//
// None.
//
//--
LEAF_ENTRY(HalFlushDcachePage)
#if DBG
lw t0,KeDcacheFlushCount // get address of dcache flush count
lw t1,0(t0) // increment the count of flushes
addu t1,t1,1 //
sw t1,0(t0) // store result
#endif
.set noreorder
.set noat
lw v0,KiPcr + PcAlignedCachePolicy(zero) // get cache policy
and a0,a0,COLOR_MASK // isolate color and offset bits
li t0,FLUSH_BASE // get base flush address
or t0,t0,a0 // compute color virtual address
sll t1,a1,ENTRYLO_PFN // shift page frame into position
or t1,t1,PROTECTION_BITS // merge protection bits
or t1,t1,v0 // merge cache policy
and a0,a0,0x1000 // isolate TB entry index
beql zero,a0,10f // if eq, first entry
move t2,zero // set second page table entry
move t2,t1 // set second page table entry
move t1,zero // set first page table entry
10: mfc0 t3,wired // get TB entry index
lw v0,KiPcr + PcSecondLevelDcacheFillSize(zero) // get 2nd fill size
lw t4,KiPcr + PcFirstLevelDcacheFillSize(zero) // get 1st fill size
bnel zero,v0,15f // if ne, second level cache present
move t4,v0 // set flush block size
.set at
.set reorder
//
// Flush a page from the data cache.
//
15: DISABLE_INTERRUPTS(t5) // disable interrupts
.set noreorder
.set noat
mfc0 t6,entryhi // get current PID and VPN2
srl t7,t0,ENTRYHI_VPN2 // isolate VPN2 of virtual address
sll t7,t7,ENTRYHI_VPN2 //
and t6,t6,0xff << ENTRYHI_PID // isolate current PID
or t7,t7,t6 // merge PID with VPN2 of virtual address
mtc0 t7,entryhi // set VPN2 and PID for probe
mtc0 t1,entrylo0 // set first PTE value
mtc0 t2,entrylo1 // set second PTE value
mtc0 t3,index // set TB index value
nop // fill
tlbwi // write TB entry - 3 cycle hazzard
subu t6,t4,1 // compute block size minus one
and t7,t0,t6 // compute offset in block
addu a2,a2,t6 // round up to next block
addu a2,a2,t7 //
nor t6,t6,zero // complement block size minus one
and a2,a2,t6 // truncate length to even number
beq zero,a2,30f // if eq, no blocks to flush
and t8,t0,t6 // compute starting virtual address
addu t9,t8,a2 // compute ending virtual address
bne zero,v0,40f // if ne, second level cache present
subu t9,t9,t4 // compute ending loop address
//
// Flush the primary data cache only.
//
20: cache HIT_WRITEBACK_INVALIDATE_D,0(t8) // invalidate cache block
bne t8,t9,20b // if ne, more blocks to invalidate
addu t8,t8,t4 // compute next block address
.set at
.set reorder
30: ENABLE_INTERRUPTS(t5) // enable interrupts
j ra // return
//
// Flush the primary and secondary data caches.
//
.set noreorder
.set noat
40: cache HIT_WRITEBACK_INVALIDATE_SD,0(t8) // invalidate cache block
bne t8,t9,40b // if ne, more blocks to invalidate
addu t8,t8,t4 // compute next block address
.set at
.set reorder
ENABLE_INTERRUPTS(t5) // enable interrupts
j ra // return
.end HalFlushDcachePage
SBTTL("Purge Data Cache Page")
//++
//
// VOID
// HalPurgeDcachePage (
// IN PVOID Color,
// IN ULONG PageFrame,
// IN ULONG Length
// )
//
// Routine Description:
//
// This function purges (hit/invalidate) up to a page of data from the
// data cache.
//
// Arguments:
//
// Color (a0) - Supplies the starting virtual address and color of the
// data that is purged.
//
// PageFrame (a1) - Supplies the page frame number of the page that
// is purged.
//
// Length (a2) - Supplies the length of the region in the page that is
// purged.
//
// Return Value:
//
// None.
//
//--
LEAF_ENTRY(HalPurgeDcachePage)
#if DBG
lw t0,KeDcacheFlushCount // get address of dcache flush count
lw t1,0(t0) // increment the count of flushes
addu t1,t1,1 //
sw t1,0(t0) // store result
#endif
.set noreorder
.set noat
lw v0,KiPcr + PcAlignedCachePolicy(zero) // get cache policy
and a0,a0,COLOR_MASK // isolate color bits
li t0,FLUSH_BASE // get base flush address
or t0,t0,a0 // compute color virtual address
sll t1,a1,ENTRYLO_PFN // shift page frame into position
or t1,t1,PROTECTION_BITS // merge protection bits
or t1,t1,v0 // merge cache policy
and a0,a0,0x1000 // isolate TB entry index
beql zero,a0,10f // if eq, first entry
move t2,zero // set second page table entry
move t2,t1 // set second page table entry
move t1,zero // set first page table entry
10: mfc0 t3,wired // get TB entry index
lw v0,KiPcr + PcSecondLevelDcacheFillSize(zero) // get 2nd fill size
lw t4,KiPcr + PcFirstLevelDcacheFillSize(zero) // get 1st fill size
bnel zero,v0,15f // if ne, second level cache present
move t4,v0 // set purge block size
.set at
.set reorder
//
// Purge data from the data cache.
//
15: DISABLE_INTERRUPTS(t5) // disable interrupts
.set noreorder
.set noat
mfc0 t6,entryhi // get current PID and VPN2
srl t7,t0,ENTRYHI_VPN2 // isolate VPN2 of virtual address
sll t7,t7,ENTRYHI_VPN2 //
and t6,t6,0xff << ENTRYHI_PID // isolate current PID
or t7,t7,t6 // merge PID with VPN2 of virtual address
mtc0 t7,entryhi // set VPN2 and PID for probe
mtc0 t1,entrylo0 // set first PTE value
mtc0 t2,entrylo1 // set second PTE value
mtc0 t3,index // set TB index value
nop // fill
tlbwi // write TB entry - 3 cycle hazzard
subu t6,t4,1 // compute block size minus one
and t7,t0,t6 // compute offset in block
addu a2,a2,t6 // round up to next block
addu a2,a2,t7 //
nor t6,t6,zero // complement block size minus one
and a2,a2,t6 // truncate length to even number
beq zero,a2,30f // if eq, no blocks to purge
and t8,t0,t6 // compute starting virtual address
addu t9,t8,a2 // compute ending virtual address
bne zero,v0,40f // if ne, second level cache present
subu t9,t9,t4 // compute ending loop address
//
// Purge the primary data cache only.
//
20: cache HIT_INVALIDATE_D,0(t8) // invalidate cache block
bne t8,t9,20b // if ne, more blocks to invalidate
addu t8,t8,t4 // compute next block address
.set at
.set reorder
30: ENABLE_INTERRUPTS(t5) // enable interrupts
j ra // return
//
// Purge the primary and secondary data caches.
//
.set noreorder
.set noat
40: cache HIT_INVALIDATE_SD,0(t8) // invalidate cache block
bne t8,t9,40b // if ne, more blocks to invalidate
addu t8,t8,t4 // compute next block address
.set at
.set reorder
ENABLE_INTERRUPTS(t5) // enable interrupts
j ra // return
.end HalPurgeDcachePage
SBTTL("Purge Instruction Cache Page")
//++
//
// VOID
// HalPurgeIcachePage (
// IN PVOID Color,
// IN ULONG PageFrame,
// IN ULONG Length
// )
//
// Routine Description:
//
// This function purges (hit/invalidate) up to a page fo data from the
// instruction cache.
//
// Arguments:
//
// Color (a0) - Supplies the starting virtual address and color of the
// data that is purged.
//
// PageFrame (a1) - Supplies the page frame number of the page that
// is purged.
//
// Length (a2) - Supplies the length of the region in the page that is
// purged.
//
// Return Value:
//
// None.
//
//--
LEAF_ENTRY(HalPurgeIcachePage)
#if DBG
lw t0,KeIcacheFlushCount // get address of icache flush count
lw t1,0(t0) // increment the count of flushes
addu t1,t1,1 //
sw t1,0(t0) // store result
#endif
.set noreorder
.set noat
lw v0,KiPcr + PcAlignedCachePolicy(zero) // get cache policy
and a0,a0,COLOR_MASK // isolate color bits
li t0,FLUSH_BASE // get base flush address
or t0,t0,a0 // compute color virtual address
sll t1,a1,ENTRYLO_PFN // shift page frame into position
or t1,t1,PROTECTION_BITS // merge protection bits
or t1,t1,v0 // merge cache policy
and a0,a0,0x1000 // isolate TB entry index
beql zero,a0,10f // if eq, first entry
move t2,zero // set second page table entry
move t2,t1 // set second page table entry
move t1,zero // set first page table entry
10: mfc0 t3,wired // get TB entry index
lw v0,KiPcr + PcSecondLevelIcacheFillSize(zero) // get 2nd fill size
lw t4,KiPcr + PcFirstLevelIcacheFillSize(zero) // get 1st fill size
bnel zero,v0,15f // if ne, second level cache present
move t4,v0 // set purge block size
.set at
.set reorder
//
// Purge data from the instruction cache.
//
15: DISABLE_INTERRUPTS(t5) // disable interrupts
.set noreorder
.set noat
mfc0 t6,entryhi // get current PID and VPN2
srl t7,t0,ENTRYHI_VPN2 // isolate VPN2 of virtual address
sll t7,t7,ENTRYHI_VPN2 //
and t6,t6,0xff << ENTRYHI_PID // isolate current PID
or t7,t7,t6 // merge PID with VPN2 of virtual address
mtc0 t7,entryhi // set VPN2 and PID for probe
mtc0 t1,entrylo0 // set first PTE value
mtc0 t2,entrylo1 // set second PTE value
mtc0 t3,index // set TB index value
nop // fill
tlbwi // write TB entry - 3 cycle hazzard
subu t6,t4,1 // compute block size minus one
and t7,t0,t6 // compute offset in block
addu a2,a2,t6 // round up to next block
addu a2,a2,t7 //
nor t6,t6,zero // complement block size minus one
and a2,a2,t6 // truncate length to even number
beq zero,a2,30f // if eq, no blocks to purge
and t8,t0,t6 // compute starting virtual address
addu t9,t8,a2 // compute ending virtual address
bne zero,v0,40f // if ne, second level cache present
subu t9,t9,t4 // compute ending loop address
//
// Purge the primary instruction cache only.
//
20: cache HIT_INVALIDATE_I,0(t8) // invalidate cache block
bne t8,t9,20b // if ne, more blocks to invalidate
addu t8,t8,t4 // compute next block address
.set at
.set reorder
30: ENABLE_INTERRUPTS(t5) // enable interrupts
j ra // return
//
// Purge the primary and secondary instruction caches.
//
.set noreorder
.set noat
40: cache HIT_INVALIDATE_SI,0(t8) // invalidate cache block
bne t8,t9,40b // if ne, more blocks to invalidate
addu t8,t8,t4 // compute next block address
.set at
.set reorder
ENABLE_INTERRUPTS(t5) // enable interrupts
j ra // return
.end HalPurgeIcachePage
SBTTL("Sweep Data Cache")
//++
//
// VOID
// HalSweepDcache (
// VOID
// )
//
// Routine Description:
//
// This function sweeps (index/writeback/invalidate) the entire data cache.
//
// Arguments:
//
// None.
//
// Return Value:
//
// None.
//
//--
LEAF_ENTRY(HalSweepDcache)
#if DBG
lw t0,KeDcacheFlushCount // get address of dcache flush count
lw t1,0(t0) // increment the count of flushes
addu t1,t1,1 //
sw t1,0(t0) // store result
#endif
DISABLE_INTERRUPTS(t5) // disable interrupts K002
lw t0,KiPcr + PcFirstLevelDcacheSize(zero) // get data cache size
lw t1,KiPcr + PcFirstLevelDcacheFillSize(zero) // get block size
li a0,KSEG0_BASE // set starting index value
addu a1,a0,t0 // compute ending cache address
subu a1,a1,t1 // compute ending block address
//
// Sweep the primary data cache.
//
.set noreorder
.set noat
10: cache INDEX_WRITEBACK_INVALIDATE_D,0(a0) // writeback/invalidate on index
#if defined(_MIPS_R4600) //K001
nop // fill
cache INDEX_WRITEBACK_INVALIDATE_D,8192(a0) // writeback/invalidate on index
#endif
bne a0,a1,10b // if ne, more to invalidate
addu a0,a0,t1 // compute address of next block
.set at
.set reorder
lw t0,KiPcr + PcSecondLevelDcacheSize(zero) // get data cache size
lw t1,KiPcr + PcSecondLevelDcacheFillSize(zero) // get block size
beq zero,t1,30f // if eq, no second level cache
li a0,KSEG0_BASE // set starting index value
addu a1,a0,t0 // compute ending cache address
subu a1,a1,t1 // compute ending block address
//
// Sweep the secondary data cache.
//
.set noreorder
.set noat
20: cache INDEX_WRITEBACK_INVALIDATE_SD,0(a0) // writeback/invalidate on index
bne a0,a1,20b // if ne, more to invalidate
addu a0,a0,t1 // compute address of next block
.set at
.set reorder
30:
ENABLE_INTERRUPTS(t5) // enable interrupts K002
j ra // return
.end HalSweepDcache
SBTTL("Sweep Data Cache Range")
//++
//
// VOID
// HalSweepDcacheRange (
// IN PVOID BaseAddress,
// IN ULONG Length
// )
//
// Routine Description:
//
// This function sweeps (index/writeback/invalidate) the specified range
// of virtual addresses from the primary data cache.
//
// Arguments:
//
// BaseAddress (a0) - Supplies the base address of the range that is swept
// from the data cache.
//
// Length (a1) - Supplies the length of the range that is swept from the
// data cache.
//
// Return Value:
//
// None.
//
//--
LEAF_ENTRY(HalSweepDcacheRange)
#if DBG
lw t0,KeDcacheFlushCount // get address of dcache flush count
lw t1,0(t0) // increment the count of flushes
addu t1,t1,1 //
sw t1,0(t0) // store result conditionally
#endif
DISABLE_INTERRUPTS(t5) // disable interrupts K002
and a0,a0,COLOR_MASK // isolate color and offset bits
or a0,a0,KSEG0_BASE // convert to physical address
lw t0,KiPcr + PcFirstLevelDcacheFillSize(zero) // get block size
addu a1,a0,a1 // compute ending cache address
subu a1,a1,t0 // compute ending block address
//
// Sweep the primary data cache.
//
.set noreorder
.set noat
10: cache INDEX_WRITEBACK_INVALIDATE_D,0(a0) // writeback/invalidate on index
#if defined(_MIPS_R4600)
nop // fill
cache INDEX_WRITEBACK_INVALIDATE_D,8192(a0) // writeback/invalidate on index
#endif
bne a0,a1,10b // if ne, more to invalidate
addu a0,a0,t0 // compute address of next block
.set at
.set reorder
ENABLE_INTERRUPTS(t5) // enable interrupts K002
j ra // return
.end HalSweepDcacheRange
SBTTL("Sweep Instruction Cache")
//++
//
// VOID
// HalSweepIcache (
// VOID
// )
//
// Routine Description:
//
// This function sweeps (index/invalidate) the entire instruction cache.
//
// Arguments:
//
// None.
//
// Return Value:
//
// None.
//
//--
LEAF_ENTRY(HalSweepIcache)
#if DBG
lw t0,KeIcacheFlushCount // get address of icache flush count
lw t1,0(t0) // increment the count of flushes
addu t1,t1,1 //
sw t1,0(t0) // store result
#endif
lw t0,KiPcr + PcSecondLevelIcacheSize(zero) // get instruction cache size
lw t1,KiPcr + PcSecondLevelIcacheFillSize(zero) // get fill size
beq zero,t1,20f // if eq, no second level cache
li a0,KSEG0_BASE // set starting index value
addu a1,a0,t0 // compute ending cache address
subu a1,a1,t1 // compute ending block address
//
// Sweep the secondary instruction cache.
//
.set noreorder
.set noat
10: cache INDEX_INVALIDATE_SI,0(a0) // invalidate cache line
bne a0,a1,10b // if ne, more to invalidate
addu a0,a0,t1 // compute address of next block
.set at
.set reorder
20: lw t0,KiPcr + PcFirstLevelIcacheSize(zero) // get instruction cache size
lw t1,KiPcr + PcFirstLevelIcacheFillSize(zero) // get fill size
li a0,KSEG0_BASE // set starting index value
addu a1,a0,t0 // compute ending cache address
subu a1,a1,t1 // compute ending block address
//
// Sweep the primary instruction cache.
//
#if defined(_MIPS_R4600)
DISABLE_INTERRUPTS(t0) // disable interrupts
#endif
.set noreorder
.set noat
30: cache INDEX_INVALIDATE_I,0(a0) // invalidate cache line
#if defined(_MIPS_R4600) //K001
nop // fill
cache INDEX_INVALIDATE_I,8192(a0) // writeback/invalidate on index
#endif
bne a0,a1,30b // if ne, more to invalidate
addu a0,a0,t1 // compute address of next block
.set at
.set reorder
#if defined(_MIPS_R4600)
ENABLE_INTERRUPTS(t0) // enable interrupts
#endif
j ra // return
.end HalSweepIcache
SBTTL("Sweep Instruction Cache Range")
//++
//
// VOID
// HalSweepIcacheRange (
// IN PVOID BaseAddress,
// IN ULONG Length
// )
//
// Routine Description:
//
// This function sweeps (index/invalidate) the specified range of addresses
// from the instruction cache.
//
// Arguments:
//
// BaseAddress (a0) - Supplies the base address of the range that is swept
// from the instruction cache.
//
// Length (a1) - Supplies the length of the range that is swept from the
// instruction cache.
//
// Return Value:
//
// None.
//
//--
LEAF_ENTRY(HalSweepIcacheRange)
#if DBG
lw t0,KeIcacheFlushCount // get address of icache flush count
lw t1,0(t0) // increment the count of flushes
addu t1,t1,1 //
sw t1,0(t0) // store result
#endif
and a0,a0,COLOR_MASK // isolate color and offset bits
or a0,a0,KSEG0_BASE // convert to physical address
lw t0,KiPcr + PcFirstLevelIcacheFillSize(zero) // get fill size
addu a1,a0,a1 // compute ending cache address
subu a1,a1,t0 // compute ending block address
//
// Sweep the primary instruction cache.
//
#if defined(_MIPS_R4600)
DISABLE_INTERRUPTS(t1) // disable interrupts
#endif
.set noreorder
.set noat
10: cache INDEX_INVALIDATE_I,0(a0) // invalidate cache line
#if defined(_MIPS_R4600)
nop // fill
cache INDEX_INVALIDATE_I,8192(a0) // writeback/invalidate on index
#endif
bne a0,a1,10b // if ne, more to invalidate
addu a0,a0,t0 // compute address of next block
.set at
.set reorder
#if defined(_MIPS_R4600)
ENABLE_INTERRUPTS(t1) // enable interrupts
#endif
j ra // return
.end HalSweepIcacheRange
SBTTL("Zero Page")
//++
//
// VOID
// HalZeroPage (
// IN PVOID NewColor,
// IN PVOID OldColor,
// IN ULONG PageFrame
// )
//
// Routine Description:
//
// This function zeros a page of memory.
//
// The algorithm used to zero a page is as follows:
//
// 1. Purge (hit/invalidate) the page from the instruction cache
// using the old color iff the old color is not the same as
// the new color.
//
// 2. Purge (hit/invalidate) the page from the data cache using
// the old color iff the old color is not the same as the new
// color.
//
// 3. Create (create/dirty/exclusive) the page in the data cache
// using the new color.
//
// 4. Write zeros to the page using the new color.
//
// Arguments:
//
// NewColor (a0) - Supplies the page aligned virtual address of the
// new color of the page that is zeroed.
//
// OldColor (a1) - Supplies the page aligned virtual address of the
// old color of the page that is zeroed.
//
// PageFrame (a2) - Supplies the page frame number of the page that
// is zeroed.
//
// Return Value:
//
// None.
//
//--
.struct 0
.space 3 * 4 // fill
ZpRa: .space 4 // saved return address
ZpFrameLength: // length of stack frame
ZpA0: .space 4 // (a0)
ZpA1: .space 4 // (a1)
ZpA2: .space 4 // (a2)
ZpA3: .space 4 // (a3)
NESTED_ENTRY(HalZeroPage, ZpFrameLength, zero)
subu sp,sp,ZpFrameLength // allocate stack frame
sw ra,ZpRa(sp) // save return address
PROLOGUE_END
and a0,a0,COLOR_BITS // isolate new color bits
and a1,a1,COLOR_BITS // isolate old color bits
sw a0,ZpA0(sp) // save new color bits
sw a2,ZpA2(sp) // save page frame
//
// If the old page color is not equal to the new page color, then change
// the color of the page.
//
beq a0,a1,10f // if eq, colors match
jal KeChangeColorPage // chagne page color
//
// Create dirty exclusive cache blocks and zero the data.
//
10: lw a3,ZpA0(sp) // get new color bits
lw a1,ZpA2(sp) // get page frame number
.set noreorder
.set noat
lw v0,KiPcr + PcAlignedCachePolicy(zero) // get cache polciy
li t0,FLUSH_BASE // get base flush address
or t0,t0,a3 // compute new color virtual address
sll t1,a1,ENTRYLO_PFN // shift page frame into position
or t1,t1,PROTECTION_BITS // merge protection bits
or t1,t1,v0 // merge cache policy
and a3,a3,0x1000 // isolate TB entry index
beql zero,a3,20f // if eq, first entry
move t2,zero // set second page table entry
move t2,t1 // set second page table entry
move t1,zero // set first page table entry
20: mfc0 t3,wired // get TB entry index
lw t4,KiPcr + PcFirstLevelDcacheFillSize(zero) // get 1st fill size
lw v0,KiPcr + PcSecondLevelDcacheFillSize(zero) // get 2nd fill size
.set at
.set reorder
DISABLE_INTERRUPTS(t5) // disable interrupts
.set noreorder
.set noat
mfc0 t6,entryhi // get current PID and VPN2
srl t7,t0,ENTRYHI_VPN2 // isolate VPN2 of virtual address
sll t7,t7,ENTRYHI_VPN2 //
and t6,t6,0xff << ENTRYHI_PID // isolate current PID
or t7,t7,t6 // merge PID with VPN2 of virtual address
mtc0 t7,entryhi // set VPN2 and PID for probe
mtc0 t1,entrylo0 // set first PTE value
mtc0 t2,entrylo1 // set second PTE value
mtc0 t3,index // set TB index value
nop // fill
tlbwi // write TB entry - 3 cycle hazzard
addu t9,t0,PAGE_SIZE // compute ending address of block
dmtc1 zero,f0 // set write pattern
bne zero,v0,50f // if ne, second level cache present
and t8,t4,0x10 // test if 16-byte cache block
//
// Zero page in primary data cache only.
//
#if defined(_DUO_)
30: sdc1 f0,0(t0) // zero 64-byte block
sdc1 f0,8(t0) //
sdc1 f0,16(t0) //
sdc1 f0,24(t0) //
sdc1 f0,32(t0) //
sdc1 f0,40(t0) //
sdc1 f0,48(t0) //
addu t0,t0,64 // advance to next 64-byte block
bne t0,t9,30b // if ne, more to zero
sdc1 f0,-8(t0) //
#else
30: cache CREATE_DIRTY_EXCLUSIVE_D,0(t0) // create cache block
addu t0,t0,t4 // compute next block address
bne zero,t8,40f // if ne, 16-byte cache line
sdc1 f0,-16(t0) //
sdc1 f0,-24(t0) // zero 16 bytes
sdc1 f0,-32(t0) //
40: bne t0,t9,30b // if ne, more blocks to zero
sdc1 f0,-8(t0) // zero 16 bytes
#endif
.set at
.set reorder
ENABLE_INTERRUPTS(t5) // enable interrupts
lw ra,ZpRa(sp) // get return address
addu sp,sp,ZpFrameLength // deallocate stack frame
j ra // return
//
// Zero page in primary and secondary data caches.
//
.set noreorder
.set noat
#if defined(_DUO_)
50: sdc1 f0,0(t0) // zero 64-byte block
sdc1 f0,8(t0) //
sdc1 f0,16(t0) //
sdc1 f0,24(t0) //
sdc1 f0,32(t0) //
sdc1 f0,40(t0) //
sdc1 f0,48(t0) //
addu t0,t0,64 // advance to next 64-byte block
bne t0,t9,50b // if ne, more to zero
sdc1 f0,-8(t0) //
#else
50: cache CREATE_DIRTY_EXCLUSIVE_SD,0(t0) // create secondary cache block
addu v1,v0,t0 // compute ending primary block address
60: addu t0,t0,t4 // compute next block address
bne zero,t8,70f // if ne, 16-byte primary cache line
sdc1 f0,-16(t0) //
sdc1 f0,-24(t0) // zero 16 bytes
sdc1 f0,-32(t0) //
70: bne t0,v1,60b // if ne, more primary blocks to zero
sdc1 f0,-8(t0) // zero 16 bytes
bne t0,t9,50b // if ne, more secondary blocks to zero
nop // fill
#endif
.set at
.set reorder
ENABLE_INTERRUPTS(t5) // enable interrupts
lw ra,ZpRa(sp) // get return address
addu sp,sp,ZpFrameLength // deallocate stack frame
j ra // return
.end HalZeroPage