xref: /openbmc/linux/arch/s390/kernel/relocate_kernel.S (revision b24413180f5600bcb3bb70fbed5cf186b60864bd)
1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Copyright IBM Corp. 2005
4 *
5 * Author(s): Rolf Adelsberger,
6 *	      Heiko Carstens <heiko.carstens@de.ibm.com>
7 *
8 */
9
10#include <linux/linkage.h>
11#include <asm/page.h>
12#include <asm/sigp.h>
13
14/*
15 * moves the new kernel to its destination...
16 * %r2 = pointer to first kimage_entry_t
17 * %r3 = start address - where to jump to after the job is done...
18 *
19 * %r5 will be used as temp. storage
20 * %r6 holds the destination address
21 * %r7 = PAGE_SIZE
22 * %r8 holds the source address
23 * %r9 = PAGE_SIZE
24 *
25 * 0xf000 is a page_mask
26 */
27
28	.text
29ENTRY(relocate_kernel)
30		basr	%r13,0		# base address
31	.base:
32		stnsm	sys_msk-.base(%r13),0xfb	# disable DAT
33		stctg	%c0,%c15,ctlregs-.base(%r13)
34		stmg	%r0,%r15,gprregs-.base(%r13)
35		lghi	%r0,3
36		sllg	%r0,%r0,31
37		stg	%r0,0x1d0(%r0)
38		la	%r0,.back_pgm-.base(%r13)
39		stg	%r0,0x1d8(%r0)
40		la	%r1,load_psw-.base(%r13)
41		mvc	0(8,%r0),0(%r1)
42		la	%r0,.back-.base(%r13)
43		st	%r0,4(%r0)
44		oi	4(%r0),0x80
45		lghi	%r0,0
46		diag	%r0,%r0,0x308
47	.back:
48		lhi	%r1,1		# mode 1 = esame
49		sigp	%r1,%r0,SIGP_SET_ARCHITECTURE # switch to esame mode
50		sam64			# switch to 64 bit addressing mode
51		basr	%r13,0
52	.back_base:
53		oi	have_diag308-.back_base(%r13),0x01
54		lctlg	%c0,%c15,ctlregs-.back_base(%r13)
55		lmg	%r0,%r15,gprregs-.back_base(%r13)
56		j	.top
57	.back_pgm:
58		lmg	%r0,%r15,gprregs-.base(%r13)
59	.top:
60		lghi	%r7,PAGE_SIZE	# load PAGE_SIZE in r7
61		lghi	%r9,PAGE_SIZE	# load PAGE_SIZE in r9
62		lg	%r5,0(%r2)	# read another word for indirection page
63		aghi	%r2,8		# increment pointer
64		tml	%r5,0x1		# is it a destination page?
65		je	.indir_check	# NO, goto "indir_check"
66		lgr	%r6,%r5		# r6 = r5
67		nill	%r6,0xf000	# mask it out and...
68		j	.top		# ...next iteration
69	.indir_check:
70		tml	%r5,0x2		# is it a indirection page?
71		je	.done_test	# NO, goto "done_test"
72		nill	%r5,0xf000	# YES, mask out,
73		lgr	%r2,%r5		# move it into the right register,
74		j	.top		# and read next...
75	.done_test:
76		tml	%r5,0x4		# is it the done indicator?
77		je	.source_test	# NO! Well, then it should be the source indicator...
78		j	.done		# ok, lets finish it here...
79	.source_test:
80		tml	%r5,0x8		# it should be a source indicator...
81		je	.top		# NO, ignore it...
82		lgr	%r8,%r5		# r8 = r5
83		nill	%r8,0xf000	# masking
84	0:	mvcle	%r6,%r8,0x0	# copy PAGE_SIZE bytes from r8 to r6 - pad with 0
85		jo	0b
86		j	.top
87	.done:
88		sgr	%r0,%r0		# clear register r0
89		la	%r4,load_psw-.base(%r13)	# load psw-address into the register
90		o	%r3,4(%r4)	# or load address into psw
91		st	%r3,4(%r4)
92		mvc	0(8,%r0),0(%r4)	# copy psw to absolute address 0
93		tm	have_diag308-.base(%r13),0x01
94		jno	.no_diag308
95		diag	%r0,%r0,0x308
96	.no_diag308:
97		sam31			# 31 bit mode
98		sr	%r1,%r1		# erase register r1
99		sr	%r2,%r2		# erase register r2
100		sigp	%r1,%r2,SIGP_SET_ARCHITECTURE # set cpuid to zero
101		lpsw	0		# hopefully start new kernel...
102
103		.align	8
104	load_psw:
105		.long	0x00080000,0x80000000
106	sys_msk:
107		.quad	0
108	ctlregs:
109		.rept	16
110		.quad	0
111		.endr
112	gprregs:
113		.rept	16
114		.quad	0
115		.endr
116	have_diag308:
117		.byte	0
118		.align	8
119	relocate_kernel_end:
120	.align 8
121	.globl	relocate_kernel_len
122	relocate_kernel_len:
123		.quad	relocate_kernel_end - relocate_kernel
124