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 
22 SYM_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
60 0:
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
67 1:
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
86 startup_kdump_relocated:
87 	basr	%r13,0
88 0:	lpswe	.Lrestart_psw-0b(%r13)		# Start new kernel...
89 SYM_CODE_END(startup_kdump)
90 	.balign	8
91 .Lrestart_psw:
92 	.quad	0x0000000080000000,0x0000000000000000 + startup
93 #else
94 SYM_CODE_START_LOCAL(startup_kdump)
95 	larl	%r13,startup_kdump_crash
96 	lpswe	0(%r13)
97 SYM_CODE_END(startup_kdump)
98 	.balign	8
99 startup_kdump_crash:
100 	.quad	0x0002000080000000,0x0000000000000000 + startup_kdump_crash
101 #endif /* CONFIG_CRASH_DUMP */
102