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| author |  Sven Schnelle <svens@linux.ibm.com>
| 2020-12-08 07:35:21 +0100 |
|---|---|---|
| committer |  Heiko Carstens <hca@linux.ibm.com>
| 2020-12-09 21:02:08 +0100 |
| commit | b5e438ebd7e808d1d2435159ac4742e01a94b8da (patch) | |
| tree | a72b50aac0baa5d2fa8bf10309915658371fb369 /arch | |
| parent | s390/mm: use invalid asce for user space when switching to init_mm (diff) | |
| download | linux-b5e438ebd7e808d1d2435159ac4742e01a94b8da.tar.gz linux-b5e438ebd7e808d1d2435159ac4742e01a94b8da.tar.bz2 linux-b5e438ebd7e808d1d2435159ac4742e01a94b8da.zip | |
s390/smp: perform initial CPU reset also for SMT siblings
Not resetting the SMT siblings might leave them in unpredictable
state. One of the observed problems was that the CPU timer wasn't
reset and therefore large system time values where accounted during
CPU bringup.
Cc: <stable@kernel.org> # 4.0
Fixes: 10ad34bc76dfb ("s390: add SMT support")
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/s390/kernel/smp.c | 18 |
1 files changed, 3 insertions, 15 deletions
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c index 647226e50c80..27c763014114 100644 --- a/arch/s390/kernel/smp.c +++ b/arch/s390/kernel/smp.c @@ -890,24 +890,12 @@ static void __no_sanitize_address smp_start_secondary(void *cpuvoid) /* Upping and downing of CPUs */ int __cpu_up(unsigned int cpu, struct task_struct *tidle) { - struct pcpu *pcpu; - int base, i, rc; + struct pcpu *pcpu = pcpu_devices + cpu; + int rc; - pcpu = pcpu_devices + cpu; if (pcpu->state != CPU_STATE_CONFIGURED) return -EIO; - base = smp_get_base_cpu(cpu); - for (i = 0; i <= smp_cpu_mtid; i++) { - if (base + i < nr_cpu_ids) - if (cpu_online(base + i)) - break; - } - /* - * If this is the first CPU of the core to get online - * do an initial CPU reset. - */ - if (i > smp_cpu_mtid && - pcpu_sigp_retry(pcpu_devices + base, SIGP_INITIAL_CPU_RESET, 0) != + if (pcpu_sigp_retry(pcpu, SIGP_INITIAL_CPU_RESET, 0) != SIGP_CC_ORDER_CODE_ACCEPTED) return -EIO; |