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| author | Sven Schnelle <svens@linux.ibm.com> | 2020-12-08 09:35:21 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-12-29 15:47:05 +0300 |
| commit | aca4660cbebcfb45817bc4bfe2a54a5d5404271e (patch) | |
| tree | a4e8ba1470821b296097b67fbf628930fbb27ca0 /arch | |
| parent | 683e90ddb947a8b97bc086e85512105d2c1da6b5 (diff) | |
| download | linux-aca4660cbebcfb45817bc4bfe2a54a5d5404271e.tar.xz | |
s390/smp: perform initial CPU reset also for SMT siblings
commit b5e438ebd7e808d1d2435159ac4742e01a94b8da upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 808f4fbe869e..40946c8587a5 100644 --- a/arch/s390/kernel/smp.c +++ b/arch/s390/kernel/smp.c @@ -864,24 +864,12 @@ static void 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; |