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 */