If you don't know what to do here, say Y.
+config ARM_CPU_TOPOLOGY
+ bool "Support cpu topology definition"
+ depends on SMP && CPU_V7
+ default y
+ help
+ Support ARM cpu topology definition. The MPIDR register defines
+ affinity between processors which is then used to describe the cpu
+ topology of an ARM System.
+
+config SCHED_MC
+ bool "Multi-core scheduler support"
+ depends on ARM_CPU_TOPOLOGY
+ help
+ Multi-core scheduler support improves the CPU scheduler's decision
+ making when dealing with multi-core CPU chips at a cost of slightly
+ increased overhead in some places. If unsure say N here.
+
+config SCHED_SMT
+ bool "SMT scheduler support"
+ depends on ARM_CPU_TOPOLOGY
+ help
+ Improves the CPU scheduler's decision making when dealing with
+ MultiThreading at a cost of slightly increased overhead in some
+ places. If unsure say N here.
+
config HAVE_ARM_SCU
bool
help
#ifndef _ASM_ARM_TOPOLOGY_H
#define _ASM_ARM_TOPOLOGY_H
+#ifdef CONFIG_ARM_CPU_TOPOLOGY
+
+#include <linux/cpumask.h>
+
+struct cputopo_arm {
+ int thread_id;
+ int core_id;
+ int socket_id;
+ cpumask_t thread_sibling;
+ cpumask_t core_sibling;
+};
+
+extern struct cputopo_arm cpu_topology[NR_CPUS];
+
+#define topology_physical_package_id(cpu) (cpu_topology[cpu].socket_id)
+#define topology_core_id(cpu) (cpu_topology[cpu].core_id)
+#define topology_core_cpumask(cpu) (&cpu_topology[cpu].core_sibling)
+#define topology_thread_cpumask(cpu) (&cpu_topology[cpu].thread_sibling)
+
+#define mc_capable() (cpu_topology[0].socket_id != -1)
+#define smt_capable() (cpu_topology[0].thread_id != -1)
+
+void init_cpu_topology(void);
+void store_cpu_topology(unsigned int cpuid);
+const struct cpumask *cpu_coregroup_mask(unsigned int cpu);
+
+#else
+
+static inline void init_cpu_topology(void) { }
+static inline void store_cpu_topology(unsigned int cpuid) { }
+
+#endif
+
#include <asm-generic/topology.h>
#endif /* _ASM_ARM_TOPOLOGY_H */
--- /dev/null
+/*
+ * arch/arm/kernel/topology.c
+ *
+ * Copyright (C) 2011 Linaro Limited.
+ * Written by: Vincent Guittot
+ *
+ * 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/cputype.h>
+#include <asm/topology.h>
+
+#define MPIDR_SMP_BITMASK (0x3 << 30)
+#define MPIDR_SMP_VALUE (0x2 << 30)
+
+#define MPIDR_MT_BITMASK (0x1 << 24)
+
+/*
+ * These masks reflect the current use of the affinity levels.
+ * The affinity level can be up to 16 bits according to ARM ARM
+ */
+
+#define MPIDR_LEVEL0_MASK 0x3
+#define MPIDR_LEVEL0_SHIFT 0
+
+#define MPIDR_LEVEL1_MASK 0xF
+#define MPIDR_LEVEL1_SHIFT 8
+
+#define MPIDR_LEVEL2_MASK 0xFF
+#define MPIDR_LEVEL2_SHIFT 16
+
+struct cputopo_arm cpu_topology[NR_CPUS];
+
+const struct cpumask *cpu_coregroup_mask(unsigned int cpu)
+{
+ return &cpu_topology[cpu].core_sibling;
+}
+
+/*
+ * 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 store_cpu_topology(unsigned int cpuid)
+{
+ struct cputopo_arm *cpuid_topo = &cpu_topology[cpuid];
+ unsigned int mpidr;
+ unsigned int cpu;
+
+ /* If the cpu topology has been already set, just return */
+ if (cpuid_topo->core_id != -1)
+ return;
+
+ mpidr = read_cpuid_mpidr();
+
+ /* create cpu topology mapping */
+ if ((mpidr & MPIDR_SMP_BITMASK) == MPIDR_SMP_VALUE) {
+ /*
+ * This is a multiprocessor system
+ * multiprocessor format & multiprocessor mode field are set
+ */
+
+ if (mpidr & MPIDR_MT_BITMASK) {
+ /* core performance interdependency */
+ cpuid_topo->thread_id = (mpidr >> MPIDR_LEVEL0_SHIFT)
+ & MPIDR_LEVEL0_MASK;
+ cpuid_topo->core_id = (mpidr >> MPIDR_LEVEL1_SHIFT)
+ & MPIDR_LEVEL1_MASK;
+ cpuid_topo->socket_id = (mpidr >> MPIDR_LEVEL2_SHIFT)
+ & MPIDR_LEVEL2_MASK;
+ } else {
+ /* largely independent cores */
+ cpuid_topo->thread_id = -1;
+ cpuid_topo->core_id = (mpidr >> MPIDR_LEVEL0_SHIFT)
+ & MPIDR_LEVEL0_MASK;
+ cpuid_topo->socket_id = (mpidr >> MPIDR_LEVEL1_SHIFT)
+ & MPIDR_LEVEL1_MASK;
+ }
+ } else {
+ /*
+ * This is an uniprocessor system
+ * we are in multiprocessor format but uniprocessor system
+ * or in the old uniprocessor format
+ */
+ cpuid_topo->thread_id = -1;
+ cpuid_topo->core_id = 0;
+ cpuid_topo->socket_id = -1;
+ }
+
+ /* update core and thread sibling masks */
+ for_each_possible_cpu(cpu) {
+ struct cputopo_arm *cpu_topo = &cpu_topology[cpu];
+
+ if (cpuid_topo->socket_id == cpu_topo->socket_id) {
+ 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) {
+ cpumask_set_cpu(cpuid,
+ &cpu_topo->thread_sibling);
+ if (cpu != cpuid)
+ cpumask_set_cpu(cpu,
+ &cpuid_topo->thread_sibling);
+ }
+ }
+ }
+ smp_wmb();
+
+ printk(KERN_INFO "CPU%u: thread %d, cpu %d, socket %d, mpidr %x\n",
+ cpuid, cpu_topology[cpuid].thread_id,
+ cpu_topology[cpuid].core_id,
+ cpu_topology[cpuid].socket_id, mpidr);
+}
+
+/*
+ * init_cpu_topology is called at boot when only one cpu is running
+ * which prevent simultaneous write access to cpu_topology array
+ */
+void init_cpu_topology(void)
+{
+ unsigned int cpu;
+
+ /* init core mask */
+ for_each_possible_cpu(cpu) {
+ struct cputopo_arm *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();
+}
projects / GitHub / LineageOS / android_kernel_samsung_universal7580.git / commitdiff