[PATCH 1/5] arm64: topology: refactor reset_cpu_topology to add support for removing topology

[sudeep.holla@arm.com (Sudeep Holla)]

Currently reset_cpu_topology clears all the CPU topology information
and resets to default values. However we may need to just clear the
information when we hotplig out the CPU. In preparation to add the
support the same, let's refactor reset_cpu_topology to clear out the
information and reset them only if explicitly requested.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
---
 arch/arm64/kernel/topology.c | 31 +++++++++++++++++++------------
 1 file changed, 19 insertions(+), 12 deletions(-)

diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c
index 7415c166281f..f10babcc112b 100644
--- a/arch/arm64/kernel/topology.c
+++ b/arch/arm64/kernel/topology.c
@@ -296,28 +296,35 @@ void store_cpu_topology(unsigned int cpuid)
 	update_siblings_masks(cpuid);
 }
 
-static void __init reset_cpu_topology(void)
+static void clear_cpu_topology(int cpu, bool reset)
 {
-	unsigned int cpu;
+	struct cpu_topology *cpu_topo = &cpu_topology[cpu];
 
-	for_each_possible_cpu(cpu) {
-		struct cpu_topology *cpu_topo = &cpu_topology[cpu];
+	cpu_topo->core_id = -1;
+	cpu_topo->thread_id = -1;
+	cpu_topo->package_id = -1;
+	cpu_topo->llc_id = -1;
 
-		cpu_topo->thread_id = -1;
-		cpu_topo->core_id = 0;
-		cpu_topo->package_id = -1;
+	cpumask_clear(&cpu_topo->llc_siblings);
+	cpumask_clear(&cpu_topo->core_sibling);
+	cpumask_clear(&cpu_topo->thread_sibling);
 
-		cpu_topo->llc_id = -1;
-		cpumask_clear(&cpu_topo->llc_siblings);
+	if (reset) {
+		cpu_topo->core_id = 0;
 		cpumask_set_cpu(cpu, &cpu_topo->llc_siblings);
-
-		cpumask_clear(&cpu_topo->core_sibling);
 		cpumask_set_cpu(cpu, &cpu_topo->core_sibling);
-		cpumask_clear(&cpu_topo->thread_sibling);
 		cpumask_set_cpu(cpu, &cpu_topo->thread_sibling);
 	}
 }
 
+static void __init reset_cpu_topology(void)
+{
+	unsigned int cpu;
+
+	for_each_possible_cpu(cpu)
+		clear_cpu_topology(cpu, true);
+}
+
 #ifdef CONFIG_ACPI
 /*
  * Propagate the topology information of the processor_topology_node tree to the
-- 
2.7.4