Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit e9efed3b authored by Nathan Lynch's avatar Nathan Lynch Committed by Benjamin Herrenschmidt
Browse files

powerpc: Make core id information available to userspace 



Existing Open Firmware practice is to report each processor core as a
separate node in the device tree.  Report the value of the "reg" OF
property corresponding to a logical CPU's device node as the core_id
attribute in /sys/devices/system/cpu/cpu*/topology/core_id.

Signed-off-by: default avatarNathan Lynch <ntl@pobox.com>
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent 440a0857

arch/powerpc/kernel/smp.c

+23 −0
Original line number Diff line number Diff line
@@ -380,6 +380,29 @@ int __cpuinit __cpu_up(unsigned int cpu) 
	return 0;

}



/* Return the value of the reg property corresponding to the given

 * logical cpu.

 */

int cpu_to_core_id(int cpu)

{

	struct device_node *np;

	const int *reg;

	int id = -1;



	np = of_get_cpu_node(cpu, NULL);

	if (!np)

		goto out;



	reg = of_get_property(np, "reg", NULL);

	if (!reg)

		goto out;



	id = *reg;

out:

	of_node_put(np);

	return id;

}



/* Must be called when no change can occur to cpu_present_map,

 * i.e. during cpu online or offline.

 */

include/asm-powerpc/smp.h

+1 −0
Original line number Diff line number Diff line
@@ -63,6 +63,7 @@ extern int smp_hw_index[]; 


DECLARE_PER_CPU(cpumask_t, cpu_sibling_map);

DECLARE_PER_CPU(cpumask_t, cpu_core_map);

extern int cpu_to_core_id(int cpu);



/* Since OpenPIC has only 4 IPIs, we use slightly different message numbers.

 *

include/asm-powerpc/topology.h

+1 −0
Original line number Diff line number Diff line
@@ -109,6 +109,7 @@ static inline void sysfs_remove_device_from_node(struct sys_device *dev, 


#define topology_thread_siblings(cpu)	(per_cpu(cpu_sibling_map, cpu))

#define topology_core_siblings(cpu)	(per_cpu(cpu_core_map, cpu))

#define topology_core_id(cpu)		(cpu_to_core_id(cpu))

#endif

#endif