linux/arch/s390/kernel/head31.S
Heiko Carstens 2e5061e40a [S390] Convert machine feature detection code to C.
From: Heiko Carstens <heiko.carstens@de.ibm.com>
From: Carsten Otte <cotte@de.ibm.com>

This lets us use defines for the magic bits in machine flags instead
of using plain numbers all over the place.
In addition on newer machines features/facilities are indicated by the
result of the stfl instruction. So we use these bits instead of trying
to execute new instructions and check wether we get an exception or
not.
Also the mvpg instruction is always available when in zArch mode,
whereas the idte instruction is only available in zArch mode. This
results in some minor optimizations.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-04-30 13:38:47 +02:00

128 lines
3.3 KiB
ArmAsm

/*
* arch/s390/kernel/head31.S
*
* Copyright (C) IBM Corp. 2005,2006
*
* Author(s): Hartmut Penner <hp@de.ibm.com>
* Martin Schwidefsky <schwidefsky@de.ibm.com>
* Rob van der Heij <rvdhei@iae.nl>
* Heiko Carstens <heiko.carstens@de.ibm.com>
*
*/
#
# startup-code at 0x10000, running in absolute addressing mode
# this is called either by the ipl loader or directly by PSW restart
# or linload or SALIPL
#
.org 0x10000
startup:basr %r13,0 # get base
.LPG0: l %r13,0f-.LPG0(%r13)
b 0(%r13)
0: .long startup_continue
#
# params at 10400 (setup.h)
#
.org PARMAREA
.long 0,0 # IPL_DEVICE
.long 0,0 # INITRD_START
.long 0,0 # INITRD_SIZE
.org COMMAND_LINE
.byte "root=/dev/ram0 ro"
.byte 0
.org 0x11000
startup_continue:
basr %r13,0 # get base
.LPG1: mvi __LC_AR_MODE_ID,0 # set ESA flag (mode 0)
lctl %c0,%c15,.Lctl-.LPG1(%r13) # load control registers
l %r12,.Lparmaddr-.LPG1(%r13) # pointer to parameter area
# move IPL device to lowcore
mvc __LC_IPLDEV(4),IPL_DEVICE-PARMAREA(%r12)
#
# Setup stack
#
l %r15,.Linittu-.LPG1(%r13)
mvc __LC_CURRENT(4),__TI_task(%r15)
ahi %r15,1<<(PAGE_SHIFT+THREAD_ORDER) # init_task_union+THREAD_SIZE
st %r15,__LC_KERNEL_STACK # set end of kernel stack
ahi %r15,-96
xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) # clear backchain
#
# Save ipl parameters, clear bss memory, initialize storage key for kernel pages,
# and create a kernel NSS if the SAVESYS= parm is defined
#
l %r14,.Lstartup_init-.LPG1(%r13)
basr %r14,%r14
lpsw .Lentry-.LPG1(13) # jump to _stext in primary-space,
# virtual and never return ...
.align 8
.Lentry:.long 0x00080000,0x80000000 + _stext
.Lctl: .long 0x04b50002 # cr0: various things
.long 0 # cr1: primary space segment table
.long .Lduct # cr2: dispatchable unit control table
.long 0 # cr3: instruction authorization
.long 0 # cr4: instruction authorization
.long .Lduct # cr5: primary-aste origin
.long 0 # cr6: I/O interrupts
.long 0 # cr7: secondary space segment table
.long 0 # cr8: access registers translation
.long 0 # cr9: tracing off
.long 0 # cr10: tracing off
.long 0 # cr11: tracing off
.long 0 # cr12: tracing off
.long 0 # cr13: home space segment table
.long 0xc0000000 # cr14: machine check handling off
.long 0 # cr15: linkage stack operations
.Lmchunk:.long memory_chunk
.Lbss_bgn: .long __bss_start
.Lbss_end: .long _end
.Lparmaddr: .long PARMAREA
.Linittu: .long init_thread_union
.Lstartup_init:
.long startup_init
.align 64
.Lduct: .long 0,0,0,0,.Lduald,0,0,0
.long 0,0,0,0,0,0,0,0
.align 128
.Lduald:.rept 8
.long 0x80000000,0,0,0 # invalid access-list entries
.endr
.org 0x12000
.globl _ehead
_ehead:
#ifdef CONFIG_SHARED_KERNEL
.org 0x100000
#endif
#
# startup-code, running in absolute addressing mode
#
.globl _stext
_stext: basr %r13,0 # get base
.LPG3:
# check control registers
stctl %c0,%c15,0(%r15)
oi 2(%r15),0x40 # enable sigp emergency signal
oi 0(%r15),0x10 # switch on low address protection
lctl %c0,%c15,0(%r15)
#
lam 0,15,.Laregs-.LPG3(%r13) # load access regs needed by uaccess
l %r14,.Lstart-.LPG3(%r13)
basr %r14,%r14 # call start_kernel
#
# We returned from start_kernel ?!? PANIK
#
basr %r13,0
lpsw .Ldw-.(%r13) # load disabled wait psw
#
.align 8
.Ldw: .long 0x000a0000,0x00000000
.Lstart:.long start_kernel
.Laregs:.long 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0