From: Alexander Gordeev <agordeev@linux.ibm.com>
Date: Thu, 12 Mar 2020 11:32:23 +0100
Subject: s390/topology: remove offline CPUs from CPU topology masks
Git-commit: 52aeda7accb6d2e511a1b89142cbbf6fd2c12565
Patch-mainline: v5.7-rc1
References: jsc#SLE-13727

The CPU topology masks on s390 contain also bits of CPUs which
are offline. Currently this is already a problem, since common
code scheduler expects e.g. cpu_smt_mask() to reflect reality.

This update changes the described behaviour and s390 starts to
behave like all other architectures.

Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 arch/s390/include/asm/topology.h |    2 ++
 arch/s390/kernel/smp.c           |    6 ++++--
 arch/s390/kernel/topology.c      |    4 +++-
 3 files changed, 9 insertions(+), 3 deletions(-)

--- a/arch/s390/include/asm/topology.h
+++ b/arch/s390/include/asm/topology.h
@@ -45,6 +45,7 @@ int topology_cpu_init(struct cpu *);
 int topology_set_cpu_management(int fc);
 void topology_schedule_update(void);
 void store_topology(struct sysinfo_15_1_x *info);
+void update_cpu_masks(void);
 void topology_expect_change(void);
 const struct cpumask *cpu_coregroup_mask(int cpu);
 
@@ -54,6 +55,7 @@ static inline void topology_init_early(v
 static inline void topology_schedule_update(void) { }
 static inline int topology_cpu_init(struct cpu *cpu) { return 0; }
 static inline int topology_cpu_dedicated(int cpu_nr) { return 0; }
+static inline void update_cpu_masks(void) { }
 static inline void topology_expect_change(void) { }
 
 #endif /* CONFIG_SCHED_TOPOLOGY */
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -828,12 +828,13 @@ static void smp_init_secondary(void)
 	init_cpu_timer();
 	vtime_init();
 	pfault_init();
-	notify_cpu_starting(smp_processor_id());
+	notify_cpu_starting(cpu);
 	if (topology_cpu_dedicated(cpu))
 		set_cpu_flag(CIF_DEDICATED_CPU);
 	else
 		clear_cpu_flag(CIF_DEDICATED_CPU);
-	set_cpu_online(smp_processor_id(), true);
+	set_cpu_online(cpu, true);
+	update_cpu_masks();
 	inc_irq_stat(CPU_RST);
 	local_irq_enable();
 	cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
@@ -905,6 +906,7 @@ int __cpu_disable(void)
 	/* Handle possible pending IPIs */
 	smp_handle_ext_call();
 	set_cpu_online(smp_processor_id(), false);
+	update_cpu_masks();
 	/* Disable pseudo page faults on this cpu. */
 	pfault_fini();
 	/* Disable interrupt sources via control register. */
--- a/arch/s390/kernel/topology.c
+++ b/arch/s390/kernel/topology.c
@@ -91,6 +91,7 @@ static cpumask_t cpu_group_map(struct ma
 		cpumask_copy(&mask, cpumask_of(cpu));
 		break;
 	}
+	cpumask_and(&mask, &mask, cpu_online_mask);
 	return mask;
 }
 
@@ -106,6 +107,7 @@ static cpumask_t cpu_thread_map(unsigned
 	for (i = 0; i <= smp_cpu_mtid; i++)
 		if (cpu_present(cpu + i))
 			cpumask_set_cpu(cpu + i, &mask);
+	cpumask_and(&mask, &mask, cpu_online_mask);
 	return mask;
 }
 
@@ -245,7 +247,7 @@ int topology_set_cpu_management(int fc)
 	return rc;
 }
 
-static void update_cpu_masks(void)
+void update_cpu_masks(void)
 {
 	struct cpu_topology_s390 *topo;
 	int cpu, id;