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s390/head: set io/ext handlers to disabled wait

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Set io/ext handlers to disabled wait in the initial lowcore, so that they
are effective right from the kernel start, when a boot method used does
not rewrite this part of the lowcore for its own needs (i.e. kexec, z/vm
ipl reader boot, qemu direct boot, load from removable media or server).

When the kernel is loaded by zipl, scsi loader or qemu loader, some or
all of the io/ext/pgm handlers addresses might be rewritten. Rewrite them
to initial values again as early as possible.

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>
This commit is contained in:
Vasily Gorbik 2020-10-13 16:19:37 +02:00 committed by Heiko Carstens
parent f8394f232b
commit 13b5bd8af4
1 changed files with 13 additions and 1 deletions
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14
arch/s390/boot/head.S
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@ -62,8 +62,12 @@ __HEAD
.org __LC_RST_NEW_PSW # 0x1a0
.quad 0,iplstart
.org __LC_EXT_NEW_PSW # 0x1b0
.quad 0x0002000180000000,0x1b0 # disabled wait
.org __LC_PGM_NEW_PSW # 0x1d0
.quad 0x0000000180000000,startup_pgm_check_handler
.org __LC_IO_NEW_PSW # 0x1f0
.quad 0x0002000180000000,0x1f0 # disabled wait
.org 0x200
@ -303,6 +307,9 @@ ENTRY(startup_kdump)
sam64 # switch to 64 bit addressing mode
basr %r13,0 # get base
.LPG0:
mvc __LC_EXT_NEW_PSW(16),.Lext_new_psw-.LPG0(%r13)
mvc __LC_PGM_NEW_PSW(16),.Lpgm_new_psw-.LPG0(%r13)
mvc __LC_IO_NEW_PSW(16),.Lio_new_psw-.LPG0(%r13)
xc 0x200(256),0x200 # partially clear lowcore
xc 0x300(256),0x300
xc 0xe00(256),0xe00
@ -320,7 +327,12 @@ ENTRY(startup_kdump)
.long 0x8000 + (1<<(PAGE_SHIFT+BOOT_STACK_ORDER)) - STACK_FRAME_OVERHEAD
.align 8
6: .long 0x7fffffff,0xffffffff
.Lext_new_psw:
.quad 0x0002000180000000,0x1b0 # disabled wait
.Lpgm_new_psw:
.quad 0x0000000180000000,startup_pgm_check_handler
.Lio_new_psw:
.quad 0x0002000180000000,0x1f0 # disabled wait
.Lctl: .quad 0x04040000 # cr0: AFP registers & secondary space
.quad 0 # cr1: primary space segment table
.quad .Lduct # cr2: dispatchable unit control table