1 files changed, 142 insertions, 0 deletions
diff --git a/arch/parisc/kernel/topology.c b/arch/parisc/kernel/topology.c
new file mode 100644
index 000000000..0a10e4ddc
--- /dev/null
+++ b/arch/parisc/kernel/topology.c
@@ -0,0 +1,142 @@
+/*
+ * arch/parisc/kernel/topology.c
+ *
+ * Copyright (C) 2017 Helge Deller <deller@gmx.de>
+ *
+ * based on arch/arm/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/percpu.h>
+#include <linux/sched.h>
+#include <linux/sched/topology.h>
+
+#include <asm/topology.h>
+
+ /*
+  * cpu topology table
+  */
+struct cputopo_parisc cpu_topology[NR_CPUS] __read_mostly;
+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 cputopo_parisc *cpu_topo, *cpuid_topo = &cpu_topology[cpuid];
+	int cpu;
+
+	/* update core and thread sibling masks */
+	for_each_possible_cpu(cpu) {
+		cpu_topo = &cpu_topology[cpu];
+
+		if (cpuid_topo->socket_id != cpu_topo->socket_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);
+	}
+	smp_wmb();
+}
+
+static int dualcores_found __initdata;
+
+/*
+ * store_cpu_topology is called at boot when only one cpu is running
+ * and with the mutex cpu_hotplug.lock locked, when several cpus have booted,
+ * which prevents simultaneous write access to cpu_topology array
+ */
+void __init store_cpu_topology(unsigned int cpuid)
+{
+	struct cputopo_parisc *cpuid_topo = &cpu_topology[cpuid];
+	struct cpuinfo_parisc *p;
+	int max_socket = -1;
+	unsigned long cpu;
+
+	/* If the cpu topology has been already set, just return */
+	if (cpuid_topo->core_id != -1)
+		return;
+
+	/* create cpu topology mapping */
+	cpuid_topo->thread_id = -1;
+	cpuid_topo->core_id = 0;
+
+	p = &per_cpu(cpu_data, cpuid);
+	for_each_online_cpu(cpu) {
+		const struct cpuinfo_parisc *cpuinfo = &per_cpu(cpu_data, cpu);
+
+		if (cpu == cpuid) /* ignore current cpu */
+			continue;
+
+		if (cpuinfo->cpu_loc == p->cpu_loc) {
+			cpuid_topo->core_id = cpu_topology[cpu].core_id;
+			if (p->cpu_loc) {
+				cpuid_topo->core_id++;
+				cpuid_topo->socket_id = cpu_topology[cpu].socket_id;
+				dualcores_found = 1;
+				continue;
+			}
+		}
+
+		if (cpuid_topo->socket_id == -1)
+			max_socket = max(max_socket, cpu_topology[cpu].socket_id);
+	}
+
+	if (cpuid_topo->socket_id == -1)
+		cpuid_topo->socket_id = max_socket + 1;
+
+	update_siblings_masks(cpuid);
+
+	pr_info("CPU%u: thread %d, cpu %d, socket %d\n",
+		cpuid, cpu_topology[cpuid].thread_id,
+		cpu_topology[cpuid].core_id,
+		cpu_topology[cpuid].socket_id);
+}
+
+static struct sched_domain_topology_level parisc_mc_topology[] = {
+#ifdef CONFIG_SCHED_MC
+	{ cpu_coregroup_mask, cpu_core_flags, SD_INIT_NAME(MC) },
+#endif
+
+	{ cpu_cpu_mask, SD_INIT_NAME(DIE) },
+	{ NULL, },
+};
+
+/*
+ * 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 capacity */
+	for_each_possible_cpu(cpu) {
+		struct cputopo_parisc *cpu_topo = &(cpu_topology[cpu]);
+
+		cpu_topo->thread_id = -1;
+		cpu_topo->core_id =  -1;
+		cpu_topo->socket_id = -1;
+		cpumask_clear(&cpu_topo->core_sibling);
+		cpumask_clear(&cpu_topo->thread_sibling);
+	}
+	smp_wmb();
+
+	/* Set scheduler topology descriptor */
+	if (dualcores_found)
+		set_sched_topology(parisc_mc_topology);
+}