linux/arch/s390/kernel/head64.S
Gerald Schaefer a80313ff91 s390/kernel: introduce .dma sections
With a relocatable kernel that could reside at any place in memory, code
and data that has to stay below 2 GB needs special handling.

This patch introduces .dma sections for such text, data and ex_table.
The sections will be part of the decompressor kernel, so they will not
be relocated and stay below 2 GB. Their location is passed over to the
decompressed / relocated kernel via the .boot.preserved.data section.

The duald and aste for control register setup also need to stay below
2 GB, so move the setup code from arch/s390/kernel/head64.S to
arch/s390/boot/head.S. The duct and linkage_stack could reside above
2 GB, but their content has to be preserved for the decompresed kernel,
so they are also moved into the .dma section.

The start and end address of the .dma sections is added to vmcoreinfo,
for crash support, to help debugging in case the kernel crashed there.

Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Reviewed-by: Philipp Rudo <prudo@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29 10:47:10 +02:00

72 lines
1.8 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright IBM Corp. 1999, 2010
*
* Author(s): Hartmut Penner <hp@de.ibm.com>
* Martin Schwidefsky <schwidefsky@de.ibm.com>
* Rob van der Heij <rvdhei@iae.nl>
* Heiko Carstens <heiko.carstens@de.ibm.com>
*
*/
#include <linux/init.h>
#include <linux/linkage.h>
#include <asm/asm-offsets.h>
#include <asm/thread_info.h>
#include <asm/page.h>
#include <asm/ptrace.h>
__HEAD
ENTRY(startup_continue)
tm __LC_STFLE_FAC_LIST+5,0x80 # LPP available ?
jz 0f
xc __LC_LPP+1(7,0),__LC_LPP+1 # clear lpp and current_pid
mvi __LC_LPP,0x80 # and set LPP_MAGIC
.insn s,0xb2800000,__LC_LPP # load program parameter
0: larl %r1,tod_clock_base
mvc 0(16,%r1),__LC_BOOT_CLOCK
larl %r13,.LPG1 # get base
larl %r0,boot_vdso_data
stg %r0,__LC_VDSO_PER_CPU
#
# Setup stack
#
larl %r14,init_task
stg %r14,__LC_CURRENT
larl %r15,init_thread_union+THREAD_SIZE-STACK_FRAME_OVERHEAD
#
# Early setup functions that may not rely on an initialized bss section,
# like moving the initrd. Returns with an initialized bss section.
#
brasl %r14,startup_init_nobss
#
# Early machine initialization and detection functions.
#
brasl %r14,startup_init
# check control registers
stctg %c0,%c15,0(%r15)
oi 6(%r15),0x60 # enable sigp emergency & external call
oi 4(%r15),0x10 # switch on low address proctection
lctlg %c0,%c15,0(%r15)
lam 0,15,.Laregs-.LPG1(%r13) # load acrs needed by uaccess
brasl %r14,start_kernel # go to C code
#
# We returned from start_kernel ?!? PANIK
#
basr %r13,0
lpswe .Ldw-.(%r13) # load disabled wait psw
.align 16
.LPG1:
.Lpcmsk:.quad 0x0000000180000000
.L4malign:.quad 0xffffffffffc00000
.Lscan2g:.quad 0x80000000 + 0x20000 - 8 # 2GB + 128K - 8
.Lnop: .long 0x07000700
.Lparmaddr:
.quad PARMAREA
.align 64
.Ldw: .quad 0x0002000180000000,0x0000000000000000
.Laregs:.long 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0