linux/arch/s390/boot/head.S
Heiko Carstens 94d3477897 s390/head: get rid of 31 bit leftovers
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 <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2022-05-18 13:31:07 +02:00

321 lines
8.9 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright IBM Corp. 1999, 2010
*
* Author(s): Hartmut Penner <hp@de.ibm.com>
* Martin Schwidefsky <schwidefsky@de.ibm.com>
* Rob van der Heij <rvdhei@iae.nl>
*
* There are 5 different IPL methods
* 1) load the image directly into ram at address 0 and do an PSW restart
* 2) linload will load the image from address 0x10000 to memory 0x10000
* and start the code thru LPSW 0x0008000080010000 (VM only, deprecated)
* 3) generate the tape ipl header, store the generated image on a tape
* and ipl from it
* In case of SL tape you need to IPL 5 times to get past VOL1 etc
* 4) generate the vm reader ipl header, move the generated image to the
* VM reader (use option NOH!) and do a ipl from reader (VM only)
* 5) direct call of start by the SALIPL loader
* We use the cpuid to distinguish between VM and native ipl
* params for kernel are pushed to 0x10400 (see setup.h)
*
*/
#include <linux/init.h>
#include <linux/linkage.h>
#include <asm/asm-offsets.h>
#include <asm/page.h>
#include <asm/ptrace.h>
#include <asm/sclp.h>
#include "boot.h"
#define EP_OFFSET 0x10008
#define EP_STRING "S390EP"
#define IPL_BS 0x730
__HEAD
ipl_start:
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
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:
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:
larl %r4,_end
larl %r13,.L_hdr
clc 0(3,%r4),0(%r13) # if it is HDRx
jz .Lagain1 # skip dataset header
larl %r13,.L_eof
clc 0(3,%r4),0(%r13) # if it is EOFx
jz .Lagain1 # skip dateset trailer
lgr %r5,%r2
la %r6,COMMAND_LINE-PARMAREA(%r12)
lgr %r7,%r2
aghi %r7,1
mvcl %r6,%r4
.Lnopf:
#
# load ramdisk from ipl device
#
.Lagain2:
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:
larl %r2,_end
larl %r13,.L_hdr # skip HDRx and EOFx
clc 0(3,%r2),0(%r13)
jz .Lagain2
larl %r13,.L_eof
clc 0(3,%r2),0(%r13)
jz .Lagain2
#
# reset files in VM reader
#
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
larl %r5,.Lirb
stsch 0(%r5) # check if irq is pending
tm 30(%r5),0x0f # by verifying if any of the
jnz .Lwaitforirq # activity or status control
tm 31(%r5),0xff # bits is set in the schib
jz .Lnoreset
.Lwaitforirq:
bras %r14,.Lirqwait # wait for IO interrupt
c %r1,__LC_SUBCHANNEL_ID # compare subchannel number
jne .Lwaitforirq
larl %r5,.Lirb
tsch 0(%r5)
.Lnoreset:
j .Lnoload
#
# everything loaded, go for it
#
.Lnoload:
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)
.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"
.L_eof: .long 0xc5d6c600 /* C'EOF' */
.L_hdr: .long 0xc8c4d900 /* C'HDR' */
.align 8
.Lcpuid:.fill 8,1,0
#
# normal startup-code, running in absolute addressing mode
# this is called either by the ipl loader or directly by PSW restart
# or linload or SALIPL
#
.org STARTUP_NORMAL_OFFSET - IPL_START
SYM_CODE_START(startup)
j startup_normal
.org EP_OFFSET - IPL_START
#
# This is a list of s390 kernel entry points. At address 0x1000f the number of
# valid entry points is stored.
#
# IMPORTANT: Do not change this table, it is s390 kernel ABI!
#
.ascii EP_STRING
.byte 0x00,0x01
#
# kdump startup-code, running in 64 bit absolute addressing mode
#
.org STARTUP_KDUMP_OFFSET - IPL_START
j startup_kdump
SYM_CODE_END(startup)
SYM_CODE_START_LOCAL(startup_normal)
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
sam64 # switch to 64 bit addressing mode
larl %r13,.Lext_new_psw
mvc __LC_EXT_NEW_PSW(16),0(%r13)
larl %r13,.Lpgm_new_psw
mvc __LC_PGM_NEW_PSW(16),0(%r13)
larl %r13,.Lio_new_psw
mvc __LC_IO_NEW_PSW(16),0(%r13)
xc 0x200(256),0x200 # partially clear lowcore
xc 0x300(256),0x300
xc 0xe00(256),0xe00
xc 0xf00(256),0xf00
larl %r13,.Lctl
lctlg %c0,%c15,0(%r13) # load control registers
stcke __LC_BOOT_CLOCK
mvc __LC_LAST_UPDATE_CLOCK(8),__LC_BOOT_CLOCK+1
larl %r13,6f
spt 0(%r13)
mvc __LC_LAST_UPDATE_TIMER(8),0(%r13)
larl %r15,_stack_end-STACK_FRAME_OVERHEAD
brasl %r14,sclp_early_setup_buffer
brasl %r14,verify_facilities
brasl %r14,startup_kernel
SYM_CODE_END(startup_normal)
.align 8
6: .long 0x7fffffff,0xffffffff
.Lext_new_psw:
.quad 0x0002000180000000,0x1b0 # disabled wait
.Lpgm_new_psw:
.quad 0x0000000180000000,startup_pgm_check_handler
.Lio_new_psw:
.quad 0x0002000180000000,0x1f0 # disabled wait
.Lctl: .quad 0x04040000 # cr0: AFP registers & secondary space
.quad 0 # cr1: primary space segment table
.quad 0 # cr2: dispatchable unit control table
.quad 0 # cr3: instruction authorization
.quad 0xffff # cr4: instruction authorization
.quad 0 # cr5: primary-aste origin
.quad 0 # cr6: I/O interrupts
.quad 0 # cr7: secondary space segment table
.quad 0x0000000000008000 # cr8: access registers translation
.quad 0 # cr9: tracing off
.quad 0 # cr10: tracing off
.quad 0 # cr11: tracing off
.quad 0 # cr12: tracing off
.quad 0 # cr13: home space segment table
.quad 0xc0000000 # cr14: machine check handling off
.quad 0 # cr15: linkage stack operations
#include "head_kdump.S"
#
# This program check is active immediately after kernel start
# and until early_pgm_check_handler is set in kernel/early.c
# It simply saves general/control registers and psw in
# the save area and does disabled wait with a faulty address.
#
SYM_CODE_START_LOCAL(startup_pgm_check_handler)
stmg %r8,%r15,__LC_SAVE_AREA_SYNC
la %r8,4095
stctg %c0,%c15,__LC_CREGS_SAVE_AREA-4095(%r8)
stmg %r0,%r7,__LC_GPREGS_SAVE_AREA-4095(%r8)
mvc __LC_GPREGS_SAVE_AREA-4095+64(64,%r8),__LC_SAVE_AREA_SYNC
mvc __LC_PSW_SAVE_AREA-4095(16,%r8),__LC_PGM_OLD_PSW
mvc __LC_RETURN_PSW(16),__LC_PGM_OLD_PSW
ni __LC_RETURN_PSW,0xfc # remove IO and EX bits
ni __LC_RETURN_PSW+1,0xfb # remove MCHK bit
oi __LC_RETURN_PSW+1,0x2 # set wait state bit
larl %r9,.Lold_psw_disabled_wait
stg %r9,__LC_PGM_NEW_PSW+8
larl %r15,_dump_info_stack_end-STACK_FRAME_OVERHEAD
brasl %r14,print_pgm_check_info
.Lold_psw_disabled_wait:
la %r8,4095
lmg %r0,%r15,__LC_GPREGS_SAVE_AREA-4095(%r8)
lpswe __LC_RETURN_PSW # disabled wait
SYM_CODE_END(startup_pgm_check_handler)