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authorSven Schnelle <svens@linux.ibm.com>2020-12-08 07:35:21 +0100
committerHeiko Carstens <hca@linux.ibm.com>2020-12-09 21:02:08 +0100
commitb5e438ebd7e808d1d2435159ac4742e01a94b8da (patch)
treea72b50aac0baa5d2fa8bf10309915658371fb369 /arch/s390
parentb4d70a6134d2152d692ccc873ff6fa3351631927 (diff)
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/s390')
-rw-r--r--arch/s390/kernel/smp.c18
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;

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