1/*
  2 * arch/s390/kernel/head31.S
  3 *
  4 * Copyright (C) IBM Corp. 2005,2010
  5 *
  6 *   Author(s):	Hartmut Penner <hp@de.ibm.com>
  7 *		Martin Schwidefsky <schwidefsky@de.ibm.com>
  8 *		Rob van der Heij <rvdhei@iae.nl>
  9 *		Heiko Carstens <heiko.carstens@de.ibm.com>
 10 *
 11 */
 12
 13#include <linux/init.h>
 14#include <linux/linkage.h>
 15#include <asm/asm-offsets.h>
 16#include <asm/thread_info.h>
 17#include <asm/page.h>
 18
 19__HEAD
 20ENTRY(startup_continue)
 21	basr	%r13,0			# get base
 22.LPG1:
 23
 24	l	%r1,.Lbase_cc-.LPG1(%r13)
 25	mvc	0(8,%r1),__LC_LAST_UPDATE_CLOCK
 26	lctl	%c0,%c15,.Lctl-.LPG1(%r13) # load control registers
 27	l	%r12,.Lparmaddr-.LPG1(%r13) # pointer to parameter area
 28					# move IPL device to lowcore
 29#
 30# Setup stack
 31#
 32	l	%r15,.Linittu-.LPG1(%r13)
 33	st	%r15,__LC_THREAD_INFO	# cache thread info in lowcore
 34	mvc	__LC_CURRENT(4),__TI_task(%r15)
 35	ahi	%r15,1<<(PAGE_SHIFT+THREAD_ORDER) # init_task_union+THREAD_SIZE
 36	st	%r15,__LC_KERNEL_STACK	# set end of kernel stack
 37	ahi	%r15,-96
 38#
 39# Save ipl parameters, clear bss memory, initialize storage key for kernel pages,
 40# and create a kernel NSS if the SAVESYS= parm is defined
 41#
 42	l	%r14,.Lstartup_init-.LPG1(%r13)
 43	basr	%r14,%r14
 44	lpsw  .Lentry-.LPG1(13)		# jump to _stext in primary-space,
 45					# virtual and never return ...
 46	.align	8
 47.Lentry:.long	0x00080000,0x80000000 + _stext
 48.Lctl:	.long	0x04b50000		# cr0: various things
 49	.long	0			# cr1: primary space segment table
 50	.long	.Lduct			# cr2: dispatchable unit control table
 51	.long	0			# cr3: instruction authorization
 52	.long	0			# cr4: instruction authorization
 53	.long	.Lduct			# cr5: primary-aste origin
 54	.long	0			# cr6:	I/O interrupts
 55	.long	0			# cr7:	secondary space segment table
 56	.long	0			# cr8:	access registers translation
 57	.long	0			# cr9:	tracing off
 58	.long	0			# cr10: tracing off
 59	.long	0			# cr11: tracing off
 60	.long	0			# cr12: tracing off
 61	.long	0			# cr13: home space segment table
 62	.long	0xc0000000		# cr14: machine check handling off
 63	.long	0			# cr15: linkage stack operations
 64.Lmchunk:.long	memory_chunk
 65.Lbss_bgn:  .long __bss_start
 66.Lbss_end:  .long _end
 67.Lparmaddr: .long PARMAREA
 68.Linittu:   .long init_thread_union
 69.Lstartup_init:
 70	    .long startup_init
 71	.align	64
 72.Lduct:	.long	0,0,0,0,.Lduald,0,0,0
 73	.long	0,0,0,0,0,0,0,0
 74	.align	128
 75.Lduald:.rept	8
 76	.long	0x80000000,0,0,0	# invalid access-list entries
 77	.endr
 78.Lbase_cc:
 79	.long	sched_clock_base_cc
 80
 81ENTRY(_ehead)
 82
 83#ifdef CONFIG_SHARED_KERNEL
 84	.org	0x100000 - 0x11000	# head.o ends at 0x11000
 85#endif
 86
 87#
 88# startup-code, running in absolute addressing mode
 89#
 90ENTRY(_stext)
 91	basr	%r13,0			# get base
 92.LPG3:
 93# check control registers
 94	stctl	%c0,%c15,0(%r15)
 95	oi	2(%r15),0x40		# enable sigp emergency signal
 96	oi	0(%r15),0x10		# switch on low address protection
 97	lctl	%c0,%c15,0(%r15)
 98
 99#
100	lam	0,15,.Laregs-.LPG3(%r13) # load access regs needed by uaccess
101	l	%r14,.Lstart-.LPG3(%r13)
102	basr	%r14,%r14		# call start_kernel
103#
104# We returned from start_kernel ?!? PANIK
105#
106	basr	%r13,0
107	lpsw	.Ldw-.(%r13)		# load disabled wait psw
108#
109	.align	8
110.Ldw:	.long	0x000a0000,0x00000000
111.Lstart:.long	start_kernel
112.Laregs:.long	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0