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author | Heiko Carstens <heiko.carstens@de.ibm.com> | 2010-02-26 16:37:34 -0500 |
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committer | Martin Schwidefsky <sky@mschwide.boeblingen.de.ibm.com> | 2010-02-26 16:37:30 -0500 |
commit | 2c2df118a6440748e6fd71a510a66ee708c31494 (patch) | |
tree | 4e19684886c0c1e7261a1d68de9885302c0565f1 /arch/s390/kernel/switch_cpu64.S | |
parent | abd1ecf209b30a0ed43f0aae50f8b8ce1be2c3d1 (diff) |
[S390] smp: always reboot on cpu 0
Always reboot on logical cpu 0. This makes sure that the IPL cpu is
always the same and usually avoids strange numbering schemes between
physical and logical cpus.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/kernel/switch_cpu64.S')
-rw-r--r-- | arch/s390/kernel/switch_cpu64.S | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/arch/s390/kernel/switch_cpu64.S b/arch/s390/kernel/switch_cpu64.S new file mode 100644 index 000000000000..c73ede3c1d68 --- /dev/null +++ b/arch/s390/kernel/switch_cpu64.S | |||
@@ -0,0 +1,52 @@ | |||
1 | /* | ||
2 | * 64-bit switch cpu code | ||
3 | * | ||
4 | * Copyright IBM Corp. 2009 | ||
5 | * | ||
6 | */ | ||
7 | |||
8 | #include <asm/asm-offsets.h> | ||
9 | #include <asm/lowcore.h> | ||
10 | #include <asm/ptrace.h> | ||
11 | |||
12 | # smp_switch_to_cpu switches to destination cpu and executes the passed function | ||
13 | # Parameter: %r2 - function to call | ||
14 | # %r3 - function parameter | ||
15 | # %r4 - stack poiner | ||
16 | # %r5 - current cpu | ||
17 | # %r6 - destination cpu | ||
18 | |||
19 | .section .text | ||
20 | .align 4 | ||
21 | .globl smp_switch_to_cpu | ||
22 | smp_switch_to_cpu: | ||
23 | stmg %r6,%r15,__SF_GPRS(%r15) | ||
24 | lgr %r1,%r15 | ||
25 | aghi %r15,-STACK_FRAME_OVERHEAD | ||
26 | stg %r1,__SF_BACKCHAIN(%r15) | ||
27 | larl %r1,.gprregs | ||
28 | stmg %r0,%r15,0(%r1) | ||
29 | 1: sigp %r0,%r6,__SIGP_RESTART /* start destination CPU */ | ||
30 | brc 2,1b /* busy, try again */ | ||
31 | 2: sigp %r0,%r5,__SIGP_STOP /* stop current CPU */ | ||
32 | brc 2,2b /* busy, try again */ | ||
33 | 3: j 3b | ||
34 | |||
35 | .globl smp_restart_cpu | ||
36 | smp_restart_cpu: | ||
37 | larl %r1,.gprregs | ||
38 | lmg %r0,%r15,0(%r1) | ||
39 | 1: sigp %r0,%r5,__SIGP_SENSE /* Wait for calling CPU */ | ||
40 | brc 10,1b /* busy, accepted (status 0), running */ | ||
41 | tmll %r0,0x40 /* Test if calling CPU is stopped */ | ||
42 | jz 1b | ||
43 | ltgr %r4,%r4 /* New stack ? */ | ||
44 | jz 1f | ||
45 | lgr %r15,%r4 | ||
46 | 1: basr %r14,%r2 | ||
47 | |||
48 | .section .data,"aw",@progbits | ||
49 | .gprregs: | ||
50 | .rept 16 | ||
51 | .quad 0 | ||
52 | .endr | ||