xref: /openbmc/linux/arch/s390/kernel/head64.S (revision 7490ca1e)
1/*
2 * arch/s390/kernel/head64.S
3 *
4 * Copyright (C) IBM Corp. 1999,2010
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	larl	%r1,sched_clock_base_cc
22	mvc	0(8,%r1),__LC_LAST_UPDATE_CLOCK
23	larl	%r13,.LPG1		# get base
24	lctlg	%c0,%c15,.Lctl-.LPG1(%r13)	# load control registers
25	lg	%r12,.Lparmaddr-.LPG1(%r13)	# pointer to parameter area
26					# move IPL device to lowcore
27	lghi	%r0,__LC_PASTE
28	stg	%r0,__LC_VDSO_PER_CPU
29#
30# Setup stack
31#
32	larl	%r15,init_thread_union
33	stg	%r15,__LC_THREAD_INFO	# cache thread info in lowcore
34	lg	%r14,__TI_task(%r15)	# cache current in lowcore
35	stg	%r14,__LC_CURRENT
36	aghi	%r15,1<<(PAGE_SHIFT+THREAD_ORDER) # init_task_union + THREAD_SIZE
37	stg	%r15,__LC_KERNEL_STACK	# set end of kernel stack
38	aghi	%r15,-160
39#
40# Save ipl parameters, clear bss memory, initialize storage key for kernel pages,
41# and create a kernel NSS if the SAVESYS= parm is defined
42#
43	brasl	%r14,startup_init
44	lpswe	.Lentry-.LPG1(13)	# jump to _stext in primary-space,
45					# virtual and never return ...
46	.align	16
47.LPG1:
48.Lentry:.quad	0x0000000180000000,_stext
49.Lctl:	.quad	0x04040000		# cr0: AFP registers & secondary space
50	.quad	0			# cr1: primary space segment table
51	.quad	.Lduct			# cr2: dispatchable unit control table
52	.quad	0			# cr3: instruction authorization
53	.quad	0			# cr4: instruction authorization
54	.quad	.Lduct			# cr5: primary-aste origin
55	.quad	0			# cr6:	I/O interrupts
56	.quad	0			# cr7:	secondary space segment table
57	.quad	0			# cr8:	access registers translation
58	.quad	0			# cr9:	tracing off
59	.quad	0			# cr10: tracing off
60	.quad	0			# cr11: tracing off
61	.quad	0			# cr12: tracing off
62	.quad	0			# cr13: home space segment table
63	.quad	0xc0000000		# cr14: machine check handling off
64	.quad	0			# cr15: linkage stack operations
65.Lpcmsk:.quad	0x0000000180000000
66.L4malign:.quad 0xffffffffffc00000
67.Lscan2g:.quad	0x80000000 + 0x20000 - 8	# 2GB + 128K - 8
68.Lnop:	.long	0x07000700
69.Lparmaddr:
70	.quad	PARMAREA
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
79ENTRY(_ehead)
80
81#ifdef CONFIG_SHARED_KERNEL
82	.org	0x100000 - 0x11000	# head.o ends at 0x11000
83#endif
84
85#
86# startup-code, running in absolute addressing mode
87#
88ENTRY(_stext)
89	basr	%r13,0			# get base
90.LPG3:
91# check control registers
92	stctg	%c0,%c15,0(%r15)
93	oi	6(%r15),0x60		# enable sigp emergency & external call
94	oi	4(%r15),0x10		# switch on low address proctection
95	lctlg	%c0,%c15,0(%r15)
96
97	lam	0,15,.Laregs-.LPG3(%r13)	# load acrs needed by uaccess
98	brasl	%r14,start_kernel	# go to C code
99#
100# We returned from start_kernel ?!? PANIK
101#
102	basr	%r13,0
103	lpswe	.Ldw-.(%r13)		# load disabled wait psw
104
105	.align	8
106.Ldw:	.quad	0x0002000180000000,0x0000000000000000
107.Laregs:.long	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
108