unmaptlb.s
1.44 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
/**************************************************************************
* *
* Copyright (C) 1994, Silicon Graphics, Inc. *
* *
* These coded instructions, statements, and computer programs contain *
* unpublished proprietary information of Silicon Graphics, Inc., and *
* are protected by Federal copyright law. They may not be disclosed *
* to third parties or copied or duplicated in any form, in whole or *
* in part, without the prior written consent of Silicon Graphics, Inc. *
* *
**************************************************************************/
#include <asm.h>
#include <regdef.h>
#include <R4300.h>
#include <ultraerror.h>
/*
* void osUnmapTLB(int index);
*/
LEAF(osUnmapTLB)
#ifdef _DEBUG
.set reorder
bgez a0,1f # check if index >= 0
b 2f
1:
li t0,NTLBENTRIES # check if index < NTLBENTRIES
blt a0,t0,3f
2:
move a2,a0 # invoke error handler if not
li a0,ERR_OSUNMAPTLB
li a1,1
j __osError
3:
#endif
.set noreorder
mfc0 t0,C0_ENTRYHI # save TLBPID
mtc0 a0,C0_INX # set index
li t1,K0BASE # set virtual address to unmapped
mtc0 t1,C0_ENTRYHI # (necessary on R4300)
mtc0 zero,C0_ENTRYLO0 # invalidate entrylo0 (even page)
mtc0 zero,C0_ENTRYLO1 # invalidate entrylo1 (odd page)
nop # 7-5-1 = 1 nop
tlbwi # write the TLB entry
nop # 8-3-1 = 4 nop
nop
nop
nop
mtc0 t0,C0_ENTRYHI # restore saved TLBPID
j ra
nop
END(osUnmapTLB)