Commit 6bceea7a authored by Ricardo Neri's avatar Ricardo Neri Committed by Rafael J. Wysocki
Browse files

arch_topology: Relocate cpu_scale to topology.[h|c] 



arch_topology.c provides functionality to parse and scale CPU capacity.
It also provides a corresponding sysfs interface. Some architectures
parse and scale CPU capacity differently as per their own needs. On
Intel processors, for instance, it is responsibility of the Intel
P-state driver.

Relocate the implementation of that interface to a common location in
topology.c. Architectures can use the interface and populate it using
their own mechanisms.

An alternative approach would be to compile arch_topology.c even if
not needed only to get this interface. This approach would create
duplicated and conflicting functionality and data structures.

Signed-off-by: default avatarRicardo Neri <ricardo.neri-calderon@linux.intel.com>
Tested-by: default avatarChristian Loehle <christian.loehle@arm.com>
Link: https://patch.msgid.link/20250419025504.9760-2-ricardo.neri-calderon@linux.intel.com


Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 4854649b

drivers/base/arch_topology.c

+0 −52
Original line number Diff line number Diff line
@@ -154,14 +154,6 @@ void topology_set_freq_scale(const struct cpumask *cpus, unsigned long cur_freq, 
		per_cpu(arch_freq_scale, i) = scale;

}



DEFINE_PER_CPU(unsigned long, cpu_scale) = SCHED_CAPACITY_SCALE;

EXPORT_PER_CPU_SYMBOL_GPL(cpu_scale);



void topology_set_cpu_scale(unsigned int cpu, unsigned long capacity)

{

	per_cpu(cpu_scale, cpu) = capacity;

}



DEFINE_PER_CPU(unsigned long, hw_pressure);



/**
@@ -207,53 +199,9 @@ void topology_update_hw_pressure(const struct cpumask *cpus, 
}

EXPORT_SYMBOL_GPL(topology_update_hw_pressure);



static ssize_t cpu_capacity_show(struct device *dev,

				 struct device_attribute *attr,

				 char *buf)

{

	struct cpu *cpu = container_of(dev, struct cpu, dev);



	return sysfs_emit(buf, "%lu\n", topology_get_cpu_scale(cpu->dev.id));

}



static void update_topology_flags_workfn(struct work_struct *work);

static DECLARE_WORK(update_topology_flags_work, update_topology_flags_workfn);



static DEVICE_ATTR_RO(cpu_capacity);



static int cpu_capacity_sysctl_add(unsigned int cpu)

{

	struct device *cpu_dev = get_cpu_device(cpu);



	if (!cpu_dev)

		return -ENOENT;



	device_create_file(cpu_dev, &dev_attr_cpu_capacity);



	return 0;

}



static int cpu_capacity_sysctl_remove(unsigned int cpu)

{

	struct device *cpu_dev = get_cpu_device(cpu);



	if (!cpu_dev)

		return -ENOENT;



	device_remove_file(cpu_dev, &dev_attr_cpu_capacity);



	return 0;

}



static int register_cpu_capacity_sysctl(void)

{

	cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "topology/cpu-capacity",

			  cpu_capacity_sysctl_add, cpu_capacity_sysctl_remove);



	return 0;

}

subsys_initcall(register_cpu_capacity_sysctl);



static int update_topology;



int topology_update_cpu_topology(void)

drivers/base/topology.c

+52 −0
Original line number Diff line number Diff line
@@ -208,3 +208,55 @@ static int __init topology_sysfs_init(void) 
}



device_initcall(topology_sysfs_init);



DEFINE_PER_CPU(unsigned long, cpu_scale) = SCHED_CAPACITY_SCALE;

EXPORT_PER_CPU_SYMBOL_GPL(cpu_scale);



void topology_set_cpu_scale(unsigned int cpu, unsigned long capacity)

{

	per_cpu(cpu_scale, cpu) = capacity;

}



static ssize_t cpu_capacity_show(struct device *dev,

				 struct device_attribute *attr,

				 char *buf)

{

	struct cpu *cpu = container_of(dev, struct cpu, dev);



	return sysfs_emit(buf, "%lu\n", topology_get_cpu_scale(cpu->dev.id));

}



static DEVICE_ATTR_RO(cpu_capacity);



static int cpu_capacity_sysctl_add(unsigned int cpu)

{

	struct device *cpu_dev = get_cpu_device(cpu);



	if (!cpu_dev)

		return -ENOENT;



	device_create_file(cpu_dev, &dev_attr_cpu_capacity);



	return 0;

}



static int cpu_capacity_sysctl_remove(unsigned int cpu)

{

	struct device *cpu_dev = get_cpu_device(cpu);



	if (!cpu_dev)

		return -ENOENT;



	device_remove_file(cpu_dev, &dev_attr_cpu_capacity);



	return 0;

}



static int register_cpu_capacity_sysctl(void)

{

	cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "topology/cpu-capacity",

			  cpu_capacity_sysctl_add, cpu_capacity_sysctl_remove);



	return 0;

}

subsys_initcall(register_cpu_capacity_sysctl);

include/linux/arch_topology.h

+0 −8
Original line number Diff line number Diff line
@@ -14,14 +14,6 @@ int topology_update_cpu_topology(void); 
struct device_node;

bool topology_parse_cpu_capacity(struct device_node *cpu_node, int cpu);



DECLARE_PER_CPU(unsigned long, cpu_scale);



static inline unsigned long topology_get_cpu_scale(int cpu)

{

	return per_cpu(cpu_scale, cpu);

}



void topology_set_cpu_scale(unsigned int cpu, unsigned long capacity);



DECLARE_PER_CPU(unsigned long, capacity_freq_ref);

include/linux/topology.h

+9 −0
Original line number Diff line number Diff line
@@ -332,4 +332,13 @@ sched_numa_hop_mask(unsigned int node, unsigned int hops) 
	     !IS_ERR_OR_NULL(mask);					       \

	     __hops++)



DECLARE_PER_CPU(unsigned long, cpu_scale);



static inline unsigned long topology_get_cpu_scale(int cpu)

{

	return per_cpu(cpu_scale, cpu);

}



void topology_set_cpu_scale(unsigned int cpu, unsigned long capacity);



#endif /* _LINUX_TOPOLOGY_H */