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s390/head: get rid of 31 bit leftovers
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Get rid of old 31 bit leftovers within ipl code:

- convert everything to pc relative code
- use 64 bit addressing mode as early as possible
- use 64 bit arithmetics wherever possible

This way the code doesn't look as odd as before anymore.

Reviewed-by: Sven Schnelle <[email protected]>
Signed-off-by: Heiko Carstens <[email protected]>
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@hcahca
hcahca committed May 18, 2022
1 parent 8218827 commit 94d3477
Showing 1 changed file with 126 additions and 149 deletions.
275 changes: 126 additions & 149 deletions arch/s390/boot/head.S
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Original file line number Diff line number Diff line change
Expand Up @@ -29,202 +29,179 @@
#include <asm/sclp.h>
#include "boot.h"

#define ARCH_OFFSET 4

#define EP_OFFSET 0x10008
#define EP_STRING "S390EP"
#define IPL_BS 0x730

__HEAD
ipl_start:
j .Liplcont
#
# subroutine to wait for end I/O
#
.Lirqwait:
larl %r13,.Lnewpsw # set up IO interrupt psw
mvc __LC_IO_NEW_PSW(16),0(%r13)
lpsw .Lwaitpsw
.Lioint:
br %r14
.align 8
.Lnewpsw:
.quad 0x0000000080000000,.Lioint
.Lwaitpsw:
.long 0x020a0000,0x80000000+.Lioint

#
# subroutine for loading cards from the reader
#
.Lloader:
la %r4,0(%r14)
la %r3,.Lorb # r2 = address of orb into r2
la %r5,.Lirb # r4 = address of irb
la %r6,.Lccws
la %r7,20
.Linit:
st %r2,4(%r6) # initialize CCW data addresses
la %r2,0x50(%r2)
la %r6,8(%r6)
bct 7,.Linit

lctl %c6,%c6,.Lcr6 # set IO subclass mask
slr %r2,%r2
.Lldlp:
ssch 0(%r3) # load chunk of 1600 bytes
bnz .Llderr
.Lwait4irq:
bas %r14,.Lirqwait
c %r1,__LC_SUBCHANNEL_ID # compare subchannel number
bne .Lwait4irq
tsch 0(%r5)

slr %r0,%r0
ic %r0,8(%r5) # get device status
chi %r0,8 # channel end ?
be .Lcont
chi %r0,12 # channel end + device end ?
be .Lcont

l %r0,4(%r5)
s %r0,8(%r3) # r0/8 = number of ccws executed
mhi %r0,10 # *10 = number of bytes in ccws
lh %r3,10(%r5) # get residual count
sr %r0,%r3 # #ccws*80-residual=#bytes read
ar %r2,%r0

br %r4 # r2 contains the total size

.Lcont:
ahi %r2,0x640 # add 0x640 to total size
la %r6,.Lccws
la %r7,20
.Lincr:
l %r0,4(%r6) # update CCW data addresses
ahi %r0,0x640
st %r0,4(%r6)
ahi %r6,8
bct 7,.Lincr

b .Lldlp
.Llderr:
lpsw .Lcrash

.align 8
.Lorb: .long 0x00000000,0x0080ff00,.Lccws
.Lirb: .long 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
.Lcr6: .long 0xff000000
.Lloadp:.long 0,0
.align 8
.Lcrash:.long 0x000a0000,0x00000000

.align 8
.Lccws: .rept 19
.long 0x02600050,0x00000000
.endr
.long 0x02200050,0x00000000

.Liplcont:
mvi __LC_AR_MODE_ID,1 # set esame flag
slr %r0,%r0 # set cpuid to zero
lhi %r1,2 # mode 2 = esame (dump)
sigp %r1,%r0,0x12 # switch to esame mode
bras %r13,0f
.fill 16,4,0x0
0: lmh %r0,%r15,0(%r13) # clear high-order half of gprs
sam31 # switch to 31 bit addressing mode
lh %r1,__LC_SUBCHANNEL_ID # test if subchannel number
bct %r1,.Lnoload # is valid
l %r1,__LC_SUBCHANNEL_ID # load ipl subchannel number
la %r2,IPL_BS # load start address
bas %r14,.Lloader # load rest of ipl image
l %r12,.Lparm # pointer to parameter area
st %r1,IPL_DEVICE+ARCH_OFFSET-PARMAREA(%r12) # save ipl device number

sam64 # switch to 64 bit addressing mode
lgh %r1,__LC_SUBCHANNEL_ID # test if subchannel number
brctg %r1,.Lnoload # is valid
llgf %r1,__LC_SUBCHANNEL_ID # load ipl subchannel number
lghi %r2,IPL_BS # load start address
bras %r14,.Lloader # load rest of ipl image
larl %r12,parmarea # pointer to parameter area
stg %r1,IPL_DEVICE-PARMAREA(%r12) # save ipl device number
#
# load parameter file from ipl device
#
.Lagain1:
l %r2,.Linitrd # ramdisk loc. is temp
bas %r14,.Lloader # load parameter file
ltr %r2,%r2 # got anything ?
bz .Lnopf
l %r3,MAX_COMMAND_LINE_SIZE+ARCH_OFFSET-PARMAREA(%r12)
ahi %r3,-1
clr %r2,%r3
bl .Lnotrunc
lr %r2,%r3
larl %r2,_end # ramdisk loc. is temp
bras %r14,.Lloader # load parameter file
ltgr %r2,%r2 # got anything ?
jz .Lnopf
lg %r3,MAX_COMMAND_LINE_SIZE-PARMAREA(%r12)
aghi %r3,-1
clgr %r2,%r3
jl .Lnotrunc
lgr %r2,%r3
.Lnotrunc:
l %r4,.Linitrd
larl %r4,_end
larl %r13,.L_hdr
clc 0(3,%r4),0(%r13) # if it is HDRx
bz .Lagain1 # skip dataset header
jz .Lagain1 # skip dataset header
larl %r13,.L_eof
clc 0(3,%r4),0(%r13) # if it is EOFx
bz .Lagain1 # skip dateset trailer

lr %r5,%r2
jz .Lagain1 # skip dateset trailer
lgr %r5,%r2
la %r6,COMMAND_LINE-PARMAREA(%r12)
lr %r7,%r2
ahi %r7,1
lgr %r7,%r2
aghi %r7,1
mvcl %r6,%r4
.Lnopf:

#
# load ramdisk from ipl device
#
.Lagain2:
l %r2,.Linitrd # addr of ramdisk
st %r2,INITRD_START+ARCH_OFFSET-PARMAREA(%r12)
bas %r14,.Lloader # load ramdisk
st %r2,INITRD_SIZE+ARCH_OFFSET-PARMAREA(%r12) # store size of rd
ltr %r2,%r2
bnz .Lrdcont
st %r2,INITRD_START+ARCH_OFFSET-PARMAREA(%r12) # no ramdisk found
larl %r2,_end # addr of ramdisk
stg %r2,INITRD_START-PARMAREA(%r12)
bras %r14,.Lloader # load ramdisk
stg %r2,INITRD_SIZE-PARMAREA(%r12) # store size of rd
ltgr %r2,%r2
jnz .Lrdcont
stg %r2,INITRD_START-PARMAREA(%r12) # no ramdisk found
.Lrdcont:
l %r2,.Linitrd

larl %r2,_end
larl %r13,.L_hdr # skip HDRx and EOFx
clc 0(3,%r2),0(%r13)
bz .Lagain2
jz .Lagain2
larl %r13,.L_eof
clc 0(3,%r2),0(%r13)
bz .Lagain2

jz .Lagain2
#
# reset files in VM reader
#
stidp .Lcpuid # store cpuid
tm .Lcpuid,0xff # running VM ?
bno .Lnoreset
la %r2,.Lreset
lhi %r3,26
larl %r13,.Lcpuid
stidp 0(%r13) # store cpuid
tm 0(%r13),0xff # running VM ?
jno .Lnoreset
larl %r2,.Lreset
lghi %r3,26
diag %r2,%r3,8
la %r5,.Lirb
larl %r5,.Lirb
stsch 0(%r5) # check if irq is pending
tm 30(%r5),0x0f # by verifying if any of the
bnz .Lwaitforirq # activity or status control
jnz .Lwaitforirq # activity or status control
tm 31(%r5),0xff # bits is set in the schib
bz .Lnoreset
jz .Lnoreset
.Lwaitforirq:
bas %r14,.Lirqwait # wait for IO interrupt
bras %r14,.Lirqwait # wait for IO interrupt
c %r1,__LC_SUBCHANNEL_ID # compare subchannel number
bne .Lwaitforirq
la %r5,.Lirb
jne .Lwaitforirq
larl %r5,.Lirb
tsch 0(%r5)
.Lnoreset:
b .Lnoload

j .Lnoload
#
# everything loaded, go for it
#
.Lnoload:
l %r1,.Lstartup
br %r1
jg startup
#
# subroutine to wait for end I/O
#
.Lirqwait:
larl %r13,.Lnewpswmask # set up IO interrupt psw
mvc __LC_IO_NEW_PSW(8),0(%r13)
stg %r14,__LC_IO_NEW_PSW+8
larl %r13,.Lwaitpsw
lpswe 0(%r13)
.Lioint:
#
# subroutine for loading cards from the reader
#
.Lloader:
lgr %r4,%r14
larl %r3,.Lorb # r2 = address of orb into r2
larl %r5,.Lirb # r4 = address of irb
larl %r6,.Lccws
lghi %r7,20
.Linit:
st %r2,4(%r6) # initialize CCW data addresses
la %r2,0x50(%r2)
la %r6,8(%r6)
brctg %r7,.Linit
larl %r13,.Lcr6
lctlg %c6,%c6,0(%r13)
xgr %r2,%r2
.Lldlp:
ssch 0(%r3) # load chunk of 1600 bytes
jnz .Llderr
.Lwait4irq:
bras %r14,.Lirqwait
c %r1,__LC_SUBCHANNEL_ID # compare subchannel number
jne .Lwait4irq
tsch 0(%r5)
xgr %r0,%r0
ic %r0,8(%r5) # get device status
cghi %r0,8 # channel end ?
je .Lcont
cghi %r0,12 # channel end + device end ?
je .Lcont
llgf %r0,4(%r5)
sgf %r0,8(%r3) # r0/8 = number of ccws executed
mghi %r0,10 # *10 = number of bytes in ccws
llgh %r3,10(%r5) # get residual count
sgr %r0,%r3 # #ccws*80-residual=#bytes read
agr %r2,%r0
br %r4 # r2 contains the total size
.Lcont:
aghi %r2,0x640 # add 0x640 to total size
larl %r6,.Lccws
lghi %r7,20
.Lincr:
l %r0,4(%r6) # update CCW data addresses
aghi %r0,0x640
st %r0,4(%r6)
aghi %r6,8
brctg %r7,.Lincr
j .Lldlp
.Llderr:
larl %r13,.Lcrash
lpsw 0(%r13)

.Linitrd:.long _end # default address of initrd
.Lparm: .long PARMAREA
.Lstartup: .long startup
.align 8
.Lwaitpsw:
.quad 0x0202000180000000,.Lioint
.Lnewpswmask:
.quad 0x0000000180000000
.align 8
.Lorb: .long 0x00000000,0x0080ff00,.Lccws
.Lirb: .long 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
.align 8
.Lcr6: .quad 0x00000000ff000000
.align 8
.Lcrash:.long 0x000a0000,0x00000000
.align 8
.Lccws: .rept 19
.long 0x02600050,0x00000000
.endr
.long 0x02200050,0x00000000
.Lreset:.byte 0xc3,0xc8,0xc1,0xd5,0xc7,0xc5,0x40,0xd9,0xc4,0xd9,0x40
.byte 0xc1,0xd3,0xd3,0x40,0xd2,0xc5,0xc5,0xd7,0x40,0xd5,0xd6
.byte 0xc8,0xd6,0xd3,0xc4 # "change rdr all keep nohold"
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