MdePkg/Library/BaseLib/Ipf/ReadCr.s File Reference


Detailed Description

IPF specific control register reading functions
Copyright (c) 2008, Intel Corporation. All rights reserved.

This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution. The full text of the license may be found at
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THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.



AsmReadControlRegister
Reads a 64-bit control register.
Reads and returns the control register specified by Index.
If Index is invalid then 0xFFFFFFFFFFFFFFFF is returned. This function is only available on IPF.
Arguments :
On Entry : The index of the control register to read.
Return Value: The control register specified by Index.
.text
.type AsmReadControlRegister,
.proc AsmReadControlRegister
.regstk 1, 0, 0, 0

AsmReadControlRegister::
CRs are defined in the ranges 0-25 and 64-81 (with some holes).
Compact this list by subtracting 32 from the top range.
0-25, 64-81 -> 0-25, 32-49
mov r15=2
mov r14=pr // save predicates
cmp.leu p6,p7=64,in0 // p6 = CR# >= 64
;;
(p7) cmp.leu p7,p0=32,in0 // p7 = 32 <= CR# < 64
(p6) add in0=-32,in0 // if (CR >= 64) CR# -= 32
;;
(p7) mov r15=0 // if bad range (32-63)
;;
mov ret0=-1 // in case of illegal CR #
shl r15=r15,in0 // r15 = 0x2 << CR#
;;
mov pr=r15,-1
;;

At this point the predicates contain a bit field of the
CR desired. (The bit is the CR+1, since pr0 is always 1.)
.pred.rel "mutex",p1,p2,p3,p9,p17,p18,p20,p21,p22,p23,p24,p25,p26,<br> p33,p34,p35,p36,p37,p38,p39,p40,p41,p42,p43,p49,p50
(p1) mov ret0=cr.dcr // cr0
(p2) mov ret0=cr.itm // cr1
(p3) mov ret0=cr.iva // cr2
(p9) mov ret0=cr.pta // cr8
(p17) mov ret0=cr.ipsr // cr16
(p18) mov ret0=cr.isr // cr17
(p20) mov ret0=cr.iip // cr19
(p21) mov ret0=cr.ifa // cr20
(p22) mov ret0=cr.itir // cr21
(p23) mov ret0=cr.iipa // cr22
(p24) mov ret0=cr.ifs // cr23
(p25) mov ret0=cr.iim // cr24
(p26) mov ret0=cr.iha // cr25

This is the translated (-32) range.

(p33) mov ret0=cr.lid // cr64
(p34) mov ret0=cr.ivr // cr65
(p35) mov ret0=cr.tpr // cr66
(p36) mov ret0=cr.eoi // cr67
(p37) mov ret0=cr.irr0 // cr68
(p38) mov ret0=cr.irr1 // cr69
(p39) mov ret0=cr.irr2 // cr70
(p40) mov ret0=cr.irr3 // cr71
(p41) mov ret0=cr.itv // cr72
(p42) mov ret0=cr.pmv // cr73
(p43) mov ret0=cr.cmcv // cr74
(p49) mov ret0=cr.lrr0 // cr80
(p50) mov ret0=cr.lrr1 // cr81

Restore predicates and return.
mov pr=r14,-1
br.ret.sptk b0
.endp


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