linux/arch/s390/kernel/base.S
Vasily Gorbik f38b0a7439 s390: remove unused s390_base_ext_handler
s390_base_ext_handler_fn haven't been used since its introduction in
commit ab14de6c37 ("[S390] Convert memory detection into C code.").

s390_base_ext_handler itself is currently falsely storing 16 registers
at __LC_SAVE_AREA_ASYNC rewriting several following lowcore values:
cpu_flags, return_psw, return_mcck_psw, sync_enter_timer and
async_enter_timer.

Besides that s390_base_ext_handler itself is only potentially hiding
EXT interrupts which should not have happen in the first place. Any
piece of code which requires EXT interrupts before fully functional
ext_int_handler is enabled has to do it on its own, like this is done
by sclp_early_cmd() which is doing EXT interrupts handling synchronously
in sclp_early_wait_irq().

With s390_base_ext_handler removed unexpected EXT interrupt leads
to disabled wait with the address 0x1b0 (__LC_EXT_NEW_PSW), which is
currently setup in the decompressor.

Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-09 11:20:58 +01:00

42 lines
895 B
ArmAsm

/* SPDX-License-Identifier: GPL-2.0 */
/*
* arch/s390/kernel/base.S
*
* Copyright IBM Corp. 2006, 2007
* Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
* Michael Holzheu <holzheu@de.ibm.com>
*/
#include <linux/linkage.h>
#include <asm/asm-offsets.h>
#include <asm/nospec-insn.h>
#include <asm/ptrace.h>
GEN_BR_THUNK %r9
GEN_BR_THUNK %r14
ENTRY(s390_base_pgm_handler)
stmg %r0,%r15,__LC_SAVE_AREA_SYNC
basr %r13,0
0: aghi %r15,-STACK_FRAME_OVERHEAD
larl %r1,s390_base_pgm_handler_fn
lg %r9,0(%r1)
ltgr %r9,%r9
jz 1f
BASR_EX %r14,%r9
lmg %r0,%r15,__LC_SAVE_AREA_SYNC
lpswe __LC_PGM_OLD_PSW
1: lpswe disabled_wait_psw-0b(%r13)
ENDPROC(s390_base_pgm_handler)
.align 8
disabled_wait_psw:
.quad 0x0002000180000000,0x0000000000000000 + s390_base_pgm_handler
.section .bss
.align 8
.globl s390_base_pgm_handler_fn
s390_base_pgm_handler_fn:
.quad 0
.previous