Merge "arm64: topology: Add support for topology DT bindings" (abf7ec6e) · Commits · e / devices / android_kernel_sony_msm8994

arch/arm64/kernel/topology.c

+196 −8

Original line number	Diff line number	Diff line
		@@ -17,10 +17,192 @@
		#include <linux/percpu.h>
		#include <linux/node.h>
		#include <linux/nodemask.h>
		#include <linux/of.h>
		#include <linux/sched.h>

		#include <asm/topology.h>

		static int __init get_cpu_for_node(struct device_node *node)
		{
		struct device_node *cpu_node;
		int cpu;

		cpu_node = of_parse_phandle(node, "cpu", 0);
		if (!cpu_node)
		return -1;

		for_each_possible_cpu(cpu) {
		if (of_get_cpu_node(cpu, NULL) == cpu_node) {
		of_node_put(cpu_node);
		return cpu;
		}
		}

		pr_crit("Unable to find CPU node for %s\n", cpu_node->full_name);

		of_node_put(cpu_node);
		return -1;
		}

		static int __init parse_core(struct device_node *core, int cluster_id,
		int core_id)
		{
		char name[10];
		bool leaf = true;
		int i = 0;
		int cpu;
		struct device_node *t;

		do {
		snprintf(name, sizeof(name), "thread%d", i);
		t = of_get_child_by_name(core, name);
		if (t) {
		leaf = false;
		cpu = get_cpu_for_node(t);
		if (cpu >= 0) {
		cpu_topology[cpu].cluster_id = cluster_id;
		cpu_topology[cpu].core_id = core_id;
		cpu_topology[cpu].thread_id = i;
		} else {
		pr_err("%s: Can't get CPU for thread\n",
		t->full_name);
		of_node_put(t);
		return -EINVAL;
		}
		of_node_put(t);
		}
		i++;
		} while (t);

		cpu = get_cpu_for_node(core);
		if (cpu >= 0) {
		if (!leaf) {
		pr_err("%s: Core has both threads and CPU\n",
		core->full_name);
		return -EINVAL;
		}

		cpu_topology[cpu].cluster_id = cluster_id;
		cpu_topology[cpu].core_id = core_id;
		} else if (leaf) {
		pr_err("%s: Can't get CPU for leaf core\n", core->full_name);
		return -EINVAL;
		}

		return 0;
		}

		static int __init parse_cluster(struct device_node *cluster, int depth)
		{
		char name[10];
		bool leaf = true;
		bool has_cores = false;
		struct device_node *c;
		static int cluster_id __initdata;
		int core_id = 0;
		int i, ret;

		/*
		* First check for child clusters; we currently ignore any
		* information about the nesting of clusters and present the
		* scheduler with a flat list of them.
		*/
		i = 0;
		do {
		snprintf(name, sizeof(name), "cluster%d", i);
		c = of_get_child_by_name(cluster, name);
		if (c) {
		leaf = false;
		ret = parse_cluster(c, depth + 1);
		of_node_put(c);
		if (ret != 0)
		return ret;
		}
		i++;
		} while (c);

		/* Now check for cores */
		i = 0;
		do {
		snprintf(name, sizeof(name), "core%d", i);
		c = of_get_child_by_name(cluster, name);
		if (c) {
		has_cores = true;

		if (depth == 0) {
		pr_err("%s: cpu-map children should be clusters\n",
		c->full_name);
		of_node_put(c);
		return -EINVAL;
		}

		if (leaf) {
		ret = parse_core(c, cluster_id, core_id++);
		} else {
		pr_err("%s: Non-leaf cluster with core %s\n",
		cluster->full_name, name);
		ret = -EINVAL;
		}

		of_node_put(c);
		if (ret != 0)
		return ret;
		}
		i++;
		} while (c);

		if (leaf && !has_cores)
		pr_warn("%s: empty cluster\n", cluster->full_name);

		if (leaf)
		cluster_id++;

		return 0;
		}

		static int __init parse_dt_topology(void)
		{
		struct device_node cn, map;
		int ret = 0;
		int cpu;

		cn = of_find_node_by_path("/cpus");
		if (!cn) {
		pr_err("No CPU information found in DT\n");
		return 0;
		}

		/*
		* When topology is provided cpu-map is essentially a root
		* cluster with restricted subnodes.
		*/
		map = of_get_child_by_name(cn, "cpu-map");
		if (!map)
		goto out;

		ret = parse_cluster(map, 0);
		if (ret != 0)
		goto out_map;

		/*
		* Check that all cores are in the topology; the SMP code will
		* only mark cores described in the DT as possible.
		*/
		for_each_possible_cpu(cpu) {
		if (cpu_topology[cpu].cluster_id == -1) {
		pr_err("CPU%d: No topology information specified\n",
		cpu);
		ret = -EINVAL;
		}
		}

		out_map:
		of_node_put(map);
		out:
		of_node_put(cn);
		return ret;
		}

		/*
		* cpu topology table
		*/
		@@ -39,8 +221,7 @@ static void update_siblings_masks(unsigned int cpuid)

		if (cpuid_topo->cluster_id == -1) {
		/*
		* DT does not contain topology information for this cpu
		* reset it to default behaviour
		* DT does not contain topology information for this cpu.
		*/
		pr_debug("CPU%u: No topology information configured\n", cpuid);
		return;
		@@ -71,15 +252,10 @@ 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)
		static void __init reset_cpu_topology(void)
		{
		unsigned int cpu;

		/* init core mask and power*/
		for_each_possible_cpu(cpu) {
		struct cpu_topology *cpu_topo = &cpu_topology[cpu];

		@@ -93,3 +269,15 @@ void __init init_cpu_topology(void)
		cpumask_set_cpu(cpu, &cpu_topo->thread_sibling);
		}
		}

		void __init init_cpu_topology(void)
		{
		reset_cpu_topology();

		/*
		* Discard anything that was parsed if we hit an error so we
		* don't use partial information.
		*/
		if (parse_dt_topology())
		reset_cpu_topology();
		}