// SPDX-License-Identifier: GPL-2.0

#include <linux/acpi.h>
#include <linux/of.h>

#include <asm/topology.h>

static int __init parse_dt_topology(void)
{
	return 0;
}

/*
 * cpu topology table
 */
struct cpu_topology cpu_topology[NR_CPUS];
EXPORT_SYMBOL_GPL(cpu_topology);

const struct cpumask *cpu_coregroup_mask(int cpu)
{
	const cpumask_t *core_mask = cpumask_of_node(cpu_to_node(cpu));

	/* Find the smaller of NUMA, core or LLC siblings */
	if (cpumask_subset(&cpu_topology[cpu].core_sibling, core_mask)) {
		/* not numa in package, lets use the package siblings */
		core_mask = &cpu_topology[cpu].core_sibling;
	}
	if (cpu_topology[cpu].llc_id != -1) {
		if (cpumask_subset(&cpu_topology[cpu].llc_sibling, core_mask))
			core_mask = &cpu_topology[cpu].llc_sibling;
	}

	return core_mask;
}

static void update_siblings_masks(int cpuid)
{
	struct cpu_topology *cpu_topo, *cpuid_topo = &cpu_topology[cpuid];
	int cpu;

	/* update core and thread sibling masks */
	for_each_online_cpu(cpu) {
		cpu_topo = &cpu_topology[cpu];

		if (cpuid_topo->llc_id == cpu_topo->llc_id) {
			cpumask_set_cpu(cpu, &cpuid_topo->llc_sibling);
			cpumask_set_cpu(cpuid, &cpu_topo->llc_sibling);
		}

		if (cpuid_topo->package_id != cpu_topo->package_id)
			continue;

		cpumask_set_cpu(cpuid, &cpu_topo->core_sibling);
		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);
		cpumask_set_cpu(cpu, &cpuid_topo->thread_sibling);
	}
}

void store_cpu_topology(int cpuid)
{
	struct cpu_topology *cpuid_topo = &cpu_topology[cpuid];

	if (cpuid_topo->package_id != -1)
		goto topology_populated;

	cpuid_topo->core_id = cpu_to_rcid(cpuid) & CORE_ID_MASK;
	cpuid_topo->package_id = rcid_to_package(cpu_to_rcid(cpuid));
	cpuid_topo->llc_id = rcid_to_package(cpuid);
	cpuid_topo->thread_id = (cpu_to_rcid(cpuid) >> THREAD_ID_SHIFT) & THREAD_ID_MASK;

	pr_debug("CPU%u: socket %d core %d thread %d\n",
		 cpuid, cpuid_topo->package_id, cpuid_topo->core_id,
		 cpuid_topo->thread_id);

topology_populated:
	update_siblings_masks(cpuid);
}

static void clear_cpu_topology(int cpu)
{
	struct cpu_topology *cpu_topo = &cpu_topology[cpu];

	cpumask_clear(&cpu_topo->llc_sibling);
	cpumask_set_cpu(cpu, &cpu_topo->llc_sibling);

	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)
{
	int cpu;

	for_each_possible_cpu(cpu) {
		struct cpu_topology *cpu_topo = &cpu_topology[cpu];

		cpu_topo->thread_id = -1;
		cpu_topo->core_id = 0;
		cpu_topo->package_id = -1;
		cpu_topo->llc_id = -1;

		clear_cpu_topology(cpu);
	}
}

void remove_cpu_topology(int cpu)
{
	int sibling;

	for_each_cpu(sibling, topology_core_cpumask(cpu))
		cpumask_clear_cpu(cpu, topology_core_cpumask(sibling));
	for_each_cpu(sibling, topology_sibling_cpumask(cpu))
		cpumask_clear_cpu(cpu, topology_sibling_cpumask(sibling));
	for_each_cpu(sibling, topology_llc_cpumask(cpu))
		cpumask_clear_cpu(cpu, topology_llc_cpumask(sibling));

	clear_cpu_topology(cpu);
}

#ifdef CONFIG_ACPI
static int __init parse_acpi_topology(void)
{
	return 0;
}
#else
static inline int __init parse_acpi_topology(void)
{
	return -EINVAL;
}
#endif

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 (!acpi_disabled && parse_acpi_topology())
		reset_cpu_topology();
	else if (of_have_populated_dt() && parse_dt_topology())
		reset_cpu_topology();
}