xref: /linux/arch/s390/kernel/relocate_kernel.S (revision 8e07e0e3964ca4e23ce7b68e2096fe660a888942)
1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Copyright IBM Corp. 2005
4 *
5 * Author(s): Rolf Adelsberger
6 *
7 */
8
9#include <linux/linkage.h>
10#include <asm/page.h>
11#include <asm/sigp.h>
12
13/*
14 * moves the new kernel to its destination...
15 * %r2 = pointer to first kimage_entry_t
16 * %r3 = start address - where to jump to after the job is done...
17 * %r4 = subcode
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
29SYM_CODE_START(relocate_kernel)
30	basr	%r13,0		# base address
31.base:
32	lghi	%r7,PAGE_SIZE	# load PAGE_SIZE in r7
33	lghi	%r9,PAGE_SIZE	# load PAGE_SIZE in r9
34	lg	%r5,0(%r2)	# read another word for indirection page
35	aghi	%r2,8		# increment pointer
36	tml	%r5,0x1		# is it a destination page?
37	je	.indir_check	# NO, goto "indir_check"
38	lgr	%r6,%r5		# r6 = r5
39	nill	%r6,0xf000	# mask it out and...
40	j	.base		# ...next iteration
41.indir_check:
42	tml	%r5,0x2		# is it a indirection page?
43	je	.done_test	# NO, goto "done_test"
44	nill	%r5,0xf000	# YES, mask out,
45	lgr	%r2,%r5		# move it into the right register,
46	j	.base		# and read next...
47.done_test:
48	tml	%r5,0x4		# is it the done indicator?
49	je	.source_test	# NO! Well, then it should be the source indicator...
50	j	.done		# ok, lets finish it here...
51.source_test:
52	tml	%r5,0x8		# it should be a source indicator...
53	je	.base		# NO, ignore it...
54	lgr	%r8,%r5		# r8 = r5
55	nill	%r8,0xf000	# masking
560:	mvcle	%r6,%r8,0x0	# copy PAGE_SIZE bytes from r8 to r6 - pad with 0
57	jo	0b
58	j	.base
59.done:
60	lgr	%r0,%r4		# subcode
61	cghi	%r3,0
62	je	.diag
63	la	%r4,load_psw-.base(%r13)	# load psw-address into the register
64	o	%r3,4(%r4)	# or load address into psw
65	st	%r3,4(%r4)
66	mvc	0(8,%r0),0(%r4)	# copy psw to absolute address 0
67.diag:
68	diag	%r0,%r0,0x308
69SYM_CODE_END(relocate_kernel)
70
71	.balign	8
72SYM_DATA_START_LOCAL(load_psw)
73	.long	0x00080000,0x80000000
74SYM_DATA_END_LABEL(load_psw, SYM_L_LOCAL, relocate_kernel_end)
75	.balign 8
76SYM_DATA(relocate_kernel_len, .quad relocate_kernel_end - relocate_kernel)
77