linux/arch/s390/kernel/head31.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

108 lines
3.0 KiB
ArmAsm

/*
* Copyright IBM Corp. 2005, 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)
basr %r13,0 # get base
.LPG1:
l %r1,.Lbase_cc-.LPG1(%r13)
mvc 0(8,%r1),__LC_LAST_UPDATE_CLOCK
lctl %c0,%c15,.Lctl-.LPG1(%r13) # load control registers
l %r12,.Lparmaddr-.LPG1(%r13) # pointer to parameter area
# move IPL device to lowcore
#
# Setup stack
#
l %r15,.Linittu-.LPG1(%r13)
st %r15,__LC_THREAD_INFO # cache thread info in lowcore
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
#
# 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 0x04b50000 # 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
.Lbase_cc:
.long sched_clock_base_cc
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
stctl %c0,%c15,0(%r15)
oi 2(%r15),0x60 # enable sigp emergency & external call
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