1 files changed, 95 insertions, 0 deletions

diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c
new file mode 100644
index 000000000000..3e06b0be4ec8
--- /dev/null
+++ b/arch/arm64/kernel/topology.c
@@ -0,0 +1,95 @@
+/*
+ * arch/arm64/kernel/topology.c
+ *
+ * Copyright (C) 2011,2013,2014 Linaro Limited.
+ *
+ * Based on the arm32 version written by Vincent Guittot in turn based on
+ * arch/sh/kernel/topology.c
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/cpu.h>
+#include <linux/cpumask.h>
+#include <linux/init.h>
+#include <linux/percpu.h>
+#include <linux/node.h>
+#include <linux/nodemask.h>
+#include <linux/sched.h>
+
+#include <asm/topology.h>
+
+/*
+ * cpu topology table
+ */
+struct cpu_topology cpu_topology[NR_CPUS];
+EXPORT_SYMBOL_GPL(cpu_topology);
+
+const struct cpumask *cpu_coregroup_mask(int cpu)
+{
+        return &cpu_topology[cpu].core_sibling;
+}
+
+static void update_siblings_masks(unsigned int cpuid)
+{
+        struct cpu_topology *cpu_topo, *cpuid_topo = &cpu_topology[cpuid];
+        int cpu;
+
+        if (cpuid_topo->cluster_id == -1) {
+                /*
+                 * DT does not contain topology information for this cpu
+                 * reset it to default behaviour
+                 */
+                pr_debug("CPU%u: No topology information configured\n", cpuid);
+                cpuid_topo->core_id = 0;
+                cpumask_set_cpu(cpuid, &cpuid_topo->core_sibling);
+                cpumask_set_cpu(cpuid, &cpuid_topo->thread_sibling);
+                return;
+        }
+
+        /* update core and thread sibling masks */
+        for_each_possible_cpu(cpu) {
+                cpu_topo = &cpu_topology[cpu];
+
+                if (cpuid_topo->cluster_id != cpu_topo->cluster_id)
+                        continue;
+
+                cpumask_set_cpu(cpuid, &cpu_topo->core_sibling);
+                if (cpu != cpuid)
+                        cpumask_set_cpu(cpu, &cpuid_topo->core_sibling);
+
+                if (cpuid_topo->core_id != cpu_topo->core_id)
+                        continue;
+
+                cpumask_set_cpu(cpuid, &cpu_topo->thread_sibling);
+                if (cpu != cpuid)
+                        cpumask_set_cpu(cpu, &cpuid_topo->thread_sibling);
+        }
+}
+
+void store_cpu_topology(unsigned int cpuid)
+{
+        update_siblings_masks(cpuid);
+}
+
+/*
+ * init_cpu_topology is called at boot when only one cpu is running
+ * which prevent simultaneous write access to cpu_topology array
+ */
+void __init init_cpu_topology(void)
+{
+        unsigned int cpu;
+
+        /* init core mask and power*/
+        for_each_possible_cpu(cpu) {
+                struct cpu_topology *cpu_topo = &cpu_topology[cpu];
+
+                cpu_topo->thread_id = -1;
+                cpu_topo->core_id =  -1;
+                cpu_topo->cluster_id = -1;
+                cpumask_clear(&cpu_topo->core_sibling);
+                cpumask_clear(&cpu_topo->thread_sibling);
+        }
+}