1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * S390 kdump lowlevel functions (new kernel)
4 *
5 * Copyright IBM Corp. 2011
6 * Author(s): Michael Holzheu <holzheu@linux.vnet.ibm.com>
7 */
8
9#include <asm/sigp.h>
10
11#define DATAMOVER_ADDR	0x4000
12#define COPY_PAGE_ADDR	0x6000
13
14#ifdef CONFIG_CRASH_DUMP
15
16#
17# kdump entry (new kernel - not yet relocated)
18#
19# Note: This code has to be position independent
20#
21
22SYM_CODE_START_LOCAL(startup_kdump)
23	lhi	%r1,2				# mode 2 = esame (dump)
24	sigp	%r1,%r0,SIGP_SET_ARCHITECTURE	# Switch to esame mode
25	sam64					# Switch to 64 bit addressing
26	basr	%r13,0
27.Lbase:
28	larl	%r2,.Lbase_addr			# Check, if we have been
29	lg	%r2,0(%r2)			# already relocated:
30	clgr	%r2,%r13			#
31	jne	.Lrelocate			# No : Start data mover
32	lghi	%r2,0				# Yes: Start kdump kernel
33	brasl	%r14,startup_kdump_relocated
34
35.Lrelocate:
36	larl	%r4,startup
37	lg	%r2,0x418(%r4)			# Get kdump base
38	lg	%r3,0x420(%r4)			# Get kdump size
39
40	larl	%r10,.Lcopy_start		# Source of data mover
41	lghi	%r8,DATAMOVER_ADDR		# Target of data mover
42	mvc	0(256,%r8),0(%r10)		# Copy data mover code
43
44	agr	%r8,%r2				# Copy data mover to
45	mvc	0(256,%r8),0(%r10)		# reserved mem
46
47	lghi	%r14,DATAMOVER_ADDR		# Jump to copied data mover
48	basr	%r14,%r14
49.Lbase_addr:
50	.quad	.Lbase
51
52#
53# kdump data mover code (runs at address DATAMOVER_ADDR)
54#
55# r2: kdump base address
56# r3: kdump size
57#
58.Lcopy_start:
59	basr	%r13,0				# Base
600:
61	lgr	%r11,%r2			# Save kdump base address
62	lgr	%r12,%r2
63	agr	%r12,%r3			# Compute kdump end address
64
65	lghi	%r5,0
66	lghi	%r10,COPY_PAGE_ADDR		# Load copy page address
671:
68	mvc	0(256,%r10),0(%r5)		# Copy old kernel to tmp
69	mvc	0(256,%r5),0(%r11)		# Copy new kernel to old
70	mvc	0(256,%r11),0(%r10)		# Copy tmp to new
71	aghi	%r11,256
72	aghi	%r5,256
73	clgr	%r11,%r12
74	jl	1b
75
76	lg	%r14,.Lstartup_kdump-0b(%r13)
77	basr	%r14,%r14			# Start relocated kernel
78.Lstartup_kdump:
79	.long	0x00000000,0x00000000 + startup_kdump_relocated
80.Lcopy_end:
81
82#
83# Startup of kdump (relocated new kernel)
84#
85	.balign	2
86startup_kdump_relocated:
87	basr	%r13,0
880:	lpswe	.Lrestart_psw-0b(%r13)		# Start new kernel...
89SYM_CODE_END(startup_kdump)
90	.balign	8
91.Lrestart_psw:
92	.quad	0x0000000080000000,0x0000000000000000 + startup
93#else
94SYM_CODE_START_LOCAL(startup_kdump)
95	larl	%r13,startup_kdump_crash
96	lpswe	0(%r13)
97SYM_CODE_END(startup_kdump)
98	.balign	8
99startup_kdump_crash:
100	.quad	0x0002000080000000,0x0000000000000000 + startup_kdump_crash
101#endif /* CONFIG_CRASH_DUMP */
102