Commit 6d0ef689 authored by Yunhui Cui's avatar Yunhui Cui Committed by Greg Kroah-Hartman
Browse files

arch_topology: move parse_acpi_topology() to common code 



Currently, RISC-V lacks arch-specific registers for CPU topology
properties and must get them from ACPI. Thus, parse_acpi_topology()
is moved from arm64/ to drivers/ for RISC-V reuse.

Signed-off-by: default avatarYunhui Cui <cuiyunhui@bytedance.com>
Reviewed-by: default avatarSudeep Holla <sudeep.holla@arm.com>
Link: https://patch.msgid.link/20250923015409.15983-2-cuiyunhui@bytedance.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent cebd22dd

arch/arm64/include/asm/topology.h

+3 −0
Original line number Diff line number Diff line
@@ -36,6 +36,9 @@ void update_freq_counters_refs(void); 
#define arch_scale_hw_pressure topology_get_hw_pressure

#define arch_update_hw_pressure	topology_update_hw_pressure



#undef arch_cpu_is_threaded

#define arch_cpu_is_threaded() (read_cpuid_mpidr() & MPIDR_MT_BITMASK)



#include <asm-generic/topology.h>



#endif /* _ASM_ARM_TOPOLOGY_H */

arch/arm64/kernel/topology.c

+0 −101
Original line number Diff line number Diff line
@@ -25,107 +25,6 @@ 
#include <asm/cputype.h>

#include <asm/topology.h>



#ifdef CONFIG_ACPI

static bool __init acpi_cpu_is_threaded(int cpu)

{

	int is_threaded = acpi_pptt_cpu_is_thread(cpu);



	/*

	 * if the PPTT doesn't have thread information, assume a homogeneous

	 * machine and return the current CPU's thread state.

	 */

	if (is_threaded < 0)

		is_threaded = read_cpuid_mpidr() & MPIDR_MT_BITMASK;



	return !!is_threaded;

}



struct cpu_smt_info {

	unsigned int thread_num;

	int core_id;

};



/*

 * Propagate the topology information of the processor_topology_node tree to the

 * cpu_topology array.

 */

int __init parse_acpi_topology(void)

{

	unsigned int max_smt_thread_num = 1;

	struct cpu_smt_info *entry;

	struct xarray hetero_cpu;

	unsigned long hetero_id;

	int cpu, topology_id;



	if (acpi_disabled)

		return 0;



	xa_init(&hetero_cpu);



	for_each_possible_cpu(cpu) {

		topology_id = find_acpi_cpu_topology(cpu, 0);

		if (topology_id < 0)

			return topology_id;



		if (acpi_cpu_is_threaded(cpu)) {

			cpu_topology[cpu].thread_id = topology_id;

			topology_id = find_acpi_cpu_topology(cpu, 1);

			cpu_topology[cpu].core_id   = topology_id;



			/*

			 * In the PPTT, CPUs below a node with the 'identical

			 * implementation' flag have the same number of threads.

			 * Count the number of threads for only one CPU (i.e.

			 * one core_id) among those with the same hetero_id.

			 * See the comment of find_acpi_cpu_topology_hetero_id()

			 * for more details.

			 *

			 * One entry is created for each node having:

			 * - the 'identical implementation' flag

			 * - its parent not having the flag

			 */

			hetero_id = find_acpi_cpu_topology_hetero_id(cpu);

			entry = xa_load(&hetero_cpu, hetero_id);

			if (!entry) {

				entry = kzalloc(sizeof(*entry), GFP_KERNEL);

				WARN_ON_ONCE(!entry);



				if (entry) {

					entry->core_id = topology_id;

					entry->thread_num = 1;

					xa_store(&hetero_cpu, hetero_id,

						 entry, GFP_KERNEL);

				}

			} else if (entry->core_id == topology_id) {

				entry->thread_num++;

			}

		} else {

			cpu_topology[cpu].thread_id  = -1;

			cpu_topology[cpu].core_id    = topology_id;

		}

		topology_id = find_acpi_cpu_topology_cluster(cpu);

		cpu_topology[cpu].cluster_id = topology_id;

		topology_id = find_acpi_cpu_topology_package(cpu);

		cpu_topology[cpu].package_id = topology_id;

	}



	/*

	 * This is a short loop since the number of XArray elements is the

	 * number of heterogeneous CPU clusters. On a homogeneous system

	 * there's only one entry in the XArray.

	 */

	xa_for_each(&hetero_cpu, hetero_id, entry) {

		max_smt_thread_num = max(max_smt_thread_num, entry->thread_num);

		xa_erase(&hetero_cpu, hetero_id);

		kfree(entry);

	}



	cpu_smt_set_num_threads(max_smt_thread_num, max_smt_thread_num);

	xa_destroy(&hetero_cpu);

	return 0;

}

#endif



#ifdef CONFIG_ARM64_AMU_EXTN

#define read_corecnt()	read_sysreg_s(SYS_AMEVCNTR0_CORE_EL0)

#define read_constcnt()	read_sysreg_s(SYS_AMEVCNTR0_CONST_EL0)

drivers/base/arch_topology.c

+95 −1
Original line number Diff line number Diff line
@@ -823,12 +823,106 @@ void remove_cpu_topology(unsigned int cpu) 
	clear_cpu_topology(cpu);

}



#if defined(CONFIG_ARM64) || defined(CONFIG_RISCV)

struct cpu_smt_info {

	unsigned int thread_num;

	int core_id;

};



static bool __init acpi_cpu_is_threaded(int cpu)

{

	int is_threaded = acpi_pptt_cpu_is_thread(cpu);



	/*

	 * if the PPTT doesn't have thread information, check for architecture

	 * specific fallback if available

	 */

	if (is_threaded < 0)

		is_threaded = arch_cpu_is_threaded();



	return !!is_threaded;

}



/*

 * Propagate the topology information of the processor_topology_node tree to the

 * cpu_topology array.

 */

__weak int __init parse_acpi_topology(void)

{

	unsigned int max_smt_thread_num = 1;

	struct cpu_smt_info *entry;

	struct xarray hetero_cpu;

	unsigned long hetero_id;

	int cpu, topology_id;



	if (acpi_disabled)

		return 0;



	xa_init(&hetero_cpu);



	for_each_possible_cpu(cpu) {

		topology_id = find_acpi_cpu_topology(cpu, 0);

		if (topology_id < 0)

			return topology_id;



		if (acpi_cpu_is_threaded(cpu)) {

			cpu_topology[cpu].thread_id = topology_id;

			topology_id = find_acpi_cpu_topology(cpu, 1);

			cpu_topology[cpu].core_id   = topology_id;



			/*

			 * In the PPTT, CPUs below a node with the 'identical

			 * implementation' flag have the same number of threads.

			 * Count the number of threads for only one CPU (i.e.

			 * one core_id) among those with the same hetero_id.

			 * See the comment of find_acpi_cpu_topology_hetero_id()

			 * for more details.

			 *

			 * One entry is created for each node having:

			 * - the 'identical implementation' flag

			 * - its parent not having the flag

			 */

			hetero_id = find_acpi_cpu_topology_hetero_id(cpu);

			entry = xa_load(&hetero_cpu, hetero_id);

			if (!entry) {

				entry = kzalloc(sizeof(*entry), GFP_KERNEL);

				WARN_ON_ONCE(!entry);



				if (entry) {

					entry->core_id = topology_id;

					entry->thread_num = 1;

					xa_store(&hetero_cpu, hetero_id,

						 entry, GFP_KERNEL);

				}

			} else if (entry->core_id == topology_id) {

				entry->thread_num++;

			}

		} else {

			cpu_topology[cpu].thread_id  = -1;

			cpu_topology[cpu].core_id    = topology_id;

		}

		topology_id = find_acpi_cpu_topology_cluster(cpu);

		cpu_topology[cpu].cluster_id = topology_id;

		topology_id = find_acpi_cpu_topology_package(cpu);

		cpu_topology[cpu].package_id = topology_id;

	}



	/*

	 * This is a short loop since the number of XArray elements is the

	 * number of heterogeneous CPU clusters. On a homogeneous system

	 * there's only one entry in the XArray.

	 */

	xa_for_each(&hetero_cpu, hetero_id, entry) {

		max_smt_thread_num = max(max_smt_thread_num, entry->thread_num);

		xa_erase(&hetero_cpu, hetero_id);

		kfree(entry);

	}



	cpu_smt_set_num_threads(max_smt_thread_num, max_smt_thread_num);

	xa_destroy(&hetero_cpu);

	return 0;

}



#if defined(CONFIG_ARM64) || defined(CONFIG_RISCV)

void __init init_cpu_topology(void)

{

	int cpu, ret;

include/linux/arch_topology.h

+5 −0
Original line number Diff line number Diff line
@@ -80,6 +80,11 @@ extern struct cpu_topology cpu_topology[NR_CPUS]; 
#define topology_sibling_cpumask(cpu)	(&cpu_topology[cpu].thread_sibling)

#define topology_cluster_cpumask(cpu)	(&cpu_topology[cpu].cluster_sibling)

#define topology_llc_cpumask(cpu)	(&cpu_topology[cpu].llc_sibling)



#ifndef arch_cpu_is_threaded

#define arch_cpu_is_threaded()	(0)

#endif



void init_cpu_topology(void);

void store_cpu_topology(unsigned int cpuid);

const struct cpumask *cpu_coregroup_mask(int cpu);