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| author | Vasily Gorbik <gor@linux.ibm.com> | 2019-08-08 20:09:08 +0200 |
|---|---|---|
| committer | Heiko Carstens <heiko.carstens@de.ibm.com> | 2019-09-13 12:17:37 +0200 |
| commit | 724dc336b79ff965bd5773257642685cf33ed9af (patch) | |
| tree | 07e170c62e17f6158f1fa8be0e489b6802c8ecfa /arch/s390/boot/head.S | |
| parent | 9e323d45ba94262620a073a3f9945ca927c07c71 (diff) | |
| download | linux-724dc336b79ff965bd5773257642685cf33ed9af.tar.bz2 | |
s390/startup: add pgm check info printing
Try to print out startup pgm check info including exact linux kernel
version, pgm interruption code and ilc, psw and general registers. Like
the following:
Linux version 5.3.0-rc7-07282-ge7b4d41d61bd-dirty (gor@tuxmaker) #3 SMP PREEMPT Thu Sep 5 16:07:34 CEST 2019
Kernel fault: interruption code 0005 ilc:2
PSW : 0000000180000000 0000000000012e52
R:0 T:0 IO:0 EX:0 Key:0 M:0 W:0 P:0 AS:0 CC:0 PM:0 RI:0 EA:3
GPRS: 0000000000000000 00ffffffffffffff 0000000000000000 0000000000019a58
000000000000bf68 0000000000000000 0000000000000000 0000000000000000
0000000000000000 0000000000000000 000000000001a041 0000000000000000
0000000004c9c000 0000000000010070 0000000000012e42 000000000000beb0
This info makes it apparent that kernel startup failed and might help
to understand what went wrong without actual standalone dump.
Printing code runs on its own stack of 1 page (at unused 0x5000), which
should be sufficient for sclp_early_printk usage (typical stack usage
observed has been around 512 bytes).
The code has pgm check recursion prevention, despite pgm check info
printing failure (follow on pgm check) or success it restores original
faulty psw and gprs and does disabled wait.
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Diffstat (limited to 'arch/s390/boot/head.S')
| -rw-r--r-- | arch/s390/boot/head.S | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/arch/s390/boot/head.S b/arch/s390/boot/head.S index 5b79ae7b44f3..4b86a8d3c121 100644 --- a/arch/s390/boot/head.S +++ b/arch/s390/boot/head.S @@ -365,12 +365,20 @@ ENTRY(startup_pgm_check_handler) stctg %c0,%c15,__LC_CREGS_SAVE_AREA-4095(%r1) mvc __LC_GPREGS_SAVE_AREA-4095(128,%r1),__LC_SAVE_AREA_SYNC mvc __LC_PSW_SAVE_AREA-4095(16,%r1),__LC_PGM_OLD_PSW - lg %r1,__LC_SAVE_AREA_SYNC+8 mvc __LC_RETURN_PSW(16),__LC_PGM_OLD_PSW ni __LC_RETURN_PSW,0xfc # remove IO and EX bits ni __LC_RETURN_PSW+1,0xfb # remove MCHK bit oi __LC_RETURN_PSW+1,0x2 # set wait state bit + larl %r2,.Lold_psw_disabled_wait + stg %r2,__LC_PGM_NEW_PSW+8 + l %r15,.Ldump_info_stack-.Lold_psw_disabled_wait(%r2) + brasl %r14,print_pgm_check_info +.Lold_psw_disabled_wait: + la %r1,4095 + lmg %r0,%r15,__LC_GPREGS_SAVE_AREA-4095(%r1) lpswe __LC_RETURN_PSW # disabled wait +.Ldump_info_stack: + .long 0x5000 + PAGE_SIZE - STACK_FRAME_OVERHEAD ENDPROC(startup_pgm_check_handler) # |