linux/arch/s390/kernel/head64.S
Heiko Carstens 9be5f34f3f s390/mm: let kernel text section always begin at 1MB
Let the kernel text section always begin at 1MB. This allows to always have
a large frame in the identity mapping of the kernel image for beginning of
the text section, if the machine has EDAT1 support.
Moving the beginning from 64K to 1MB doesn't cost any memory, since we make
the memory between 64K and 1MB available for the page allocator.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-10-09 14:16:59 +02:00

103 lines
3.0 KiB
ArmAsm

/*
* 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>
* Heiko Carstens <heiko.carstens@de.ibm.com>
*
*/
#include <linux/init.h>
#include <linux/linkage.h>
#include <asm/asm-offsets.h>
#include <asm/thread_info.h>
#include <asm/page.h>
__HEAD
ENTRY(startup_continue)
larl %r1,sched_clock_base_cc
mvc 0(8,%r1),__LC_LAST_UPDATE_CLOCK
larl %r13,.LPG1 # get base
lctlg %c0,%c15,.Lctl-.LPG1(%r13) # load control registers
lg %r12,.Lparmaddr-.LPG1(%r13) # pointer to parameter area
# move IPL device to lowcore
lghi %r0,__LC_PASTE
stg %r0,__LC_VDSO_PER_CPU
#
# Setup stack
#
larl %r15,init_thread_union
stg %r15,__LC_THREAD_INFO # cache thread info in lowcore
lg %r14,__TI_task(%r15) # cache current in lowcore
stg %r14,__LC_CURRENT
aghi %r15,1<<(PAGE_SHIFT+THREAD_ORDER) # init_task_union + THREAD_SIZE
stg %r15,__LC_KERNEL_STACK # set end of kernel stack
aghi %r15,-160
#
# Save ipl parameters, clear bss memory, initialize storage key for kernel pages,
# and create a kernel NSS if the SAVESYS= parm is defined
#
brasl %r14,startup_init
lpswe .Lentry-.LPG1(13) # jump to _stext in primary-space,
# virtual and never return ...
.align 16
.LPG1:
.Lentry:.quad 0x0000000180000000,_stext
.Lctl: .quad 0x04040000 # cr0: AFP registers & secondary space
.quad 0 # cr1: primary space segment table
.quad .Lduct # cr2: dispatchable unit control table
.quad 0 # cr3: instruction authorization
.quad 0 # cr4: instruction authorization
.quad .Lduct # cr5: primary-aste origin
.quad 0 # cr6: I/O interrupts
.quad 0 # cr7: secondary space segment table
.quad 0 # 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
.Lpcmsk:.quad 0x0000000180000000
.L4malign:.quad 0xffffffffffc00000
.Lscan2g:.quad 0x80000000 + 0x20000 - 8 # 2GB + 128K - 8
.Lnop: .long 0x07000700
.Lparmaddr:
.quad PARMAREA
.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
ENTRY(_ehead)
.org 0x100000 - 0x11000 # head.o ends at 0x11000
#
# startup-code, running in absolute addressing mode
#
ENTRY(_stext)
basr %r13,0 # get base
.LPG3:
# check control registers
stctg %c0,%c15,0(%r15)
oi 6(%r15),0x60 # enable sigp emergency & external call
oi 4(%r15),0x10 # switch on low address proctection
lctlg %c0,%c15,0(%r15)
lam 0,15,.Laregs-.LPG3(%r13) # load acrs needed by uaccess
brasl %r14,start_kernel # go to C code
#
# We returned from start_kernel ?!? PANIK
#
basr %r13,0
lpswe .Ldw-.(%r13) # load disabled wait psw
.align 8
.Ldw: .quad 0x0002000180000000,0x0000000000000000
.Laregs:.long 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0