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		stctg	%c0,%c15,ctlregs-.base(%r13)
33		stmg	%r0,%r15,gprregs-.base(%r13)
34		lghi	%r0,3
35		sllg	%r0,%r0,31
36		stg	%r0,0x1d0(%r0)
37		la	%r0,.back_pgm-.base(%r13)
38		stg	%r0,0x1d8(%r0)
39		la	%r1,load_psw-.base(%r13)
40		mvc	0(8,%r0),0(%r1)
41		la	%r0,.back-.base(%r13)
42		st	%r0,4(%r0)
43		oi	4(%r0),0x80
44		lghi	%r0,0
45		diag	%r0,%r0,0x308
46	.back:
47		lhi	%r1,1		# mode 1 = esame
48		sigp	%r1,%r0,SIGP_SET_ARCHITECTURE # switch to esame mode
49		sam64			# switch to 64 bit addressing mode
50		basr	%r13,0
51	.back_base:
52		oi	have_diag308-.back_base(%r13),0x01
53		lctlg	%c0,%c15,ctlregs-.back_base(%r13)
54		lmg	%r0,%r15,gprregs-.back_base(%r13)
55		j	.top
56	.back_pgm:
57		lmg	%r0,%r15,gprregs-.base(%r13)
58	.top:
59		lghi	%r7,PAGE_SIZE	# load PAGE_SIZE in r7
60		lghi	%r9,PAGE_SIZE	# load PAGE_SIZE in r9
61		lg	%r5,0(%r2)	# read another word for indirection page
62		aghi	%r2,8		# increment pointer
63		tml	%r5,0x1		# is it a destination page?
64		je	.indir_check	# NO, goto "indir_check"
65		lgr	%r6,%r5		# r6 = r5
66		nill	%r6,0xf000	# mask it out and...
67		j	.top		# ...next iteration
68	.indir_check:
69		tml	%r5,0x2		# is it a indirection page?
70		je	.done_test	# NO, goto "done_test"
71		nill	%r5,0xf000	# YES, mask out,
72		lgr	%r2,%r5		# move it into the right register,
73		j	.top		# and read next...
74	.done_test:
75		tml	%r5,0x4		# is it the done indicator?
76		je	.source_test	# NO! Well, then it should be the source indicator...
77		j	.done		# ok, lets finish it here...
78	.source_test:
79		tml	%r5,0x8		# it should be a source indicator...
80		je	.top		# NO, ignore it...
81		lgr	%r8,%r5		# r8 = r5
82		nill	%r8,0xf000	# masking
83	0:	mvcle	%r6,%r8,0x0	# copy PAGE_SIZE bytes from r8 to r6 - pad with 0
84		jo	0b
85		j	.top
86	.done:
87		sgr	%r0,%r0		# clear register r0
88		la	%r4,load_psw-.base(%r13)	# load psw-address into the register
89		o	%r3,4(%r4)	# or load address into psw
90		st	%r3,4(%r4)
91		mvc	0(8,%r0),0(%r4)	# copy psw to absolute address 0
92		tm	have_diag308-.base(%r13),0x01
93		jno	.no_diag308
94		diag	%r0,%r0,0x308
95	.no_diag308:
96		sam31			# 31 bit mode
97		sr	%r1,%r1		# erase register r1
98		sr	%r2,%r2		# erase register r2
99		sigp	%r1,%r2,SIGP_SET_ARCHITECTURE # set cpuid to zero
100		lpsw	0		# hopefully start new kernel...
101
102		.align	8
103	load_psw:
104		.long	0x00080000,0x80000000
105	ctlregs:
106		.rept	16
107		.quad	0
108		.endr
109	gprregs:
110		.rept	16
111		.quad	0
112		.endr
113	have_diag308:
114		.byte	0
115		.align	8
116	relocate_kernel_end:
117	.align 8
118	.globl	relocate_kernel_len
119	relocate_kernel_len:
120		.quad	relocate_kernel_end - relocate_kernel
121