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Commit a0e71cd9 authored by Suzuki K Poulose's avatar Suzuki K Poulose Committed by Will Deacon
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of: Add helper for mapping device node to logical CPU number 



Add a helper to map a device node to a logical CPU number to avoid
duplication. Currently this is open coded in different places (e.g
gic-v3, coresight). The helper tries to map device node to a "possible"
logical CPU id, which may not be online yet. It is the responsibility
of the user to make sure that the CPU is online. The helper uses
of_cpu_device_node_get() to retrieve the device node for a given CPU
(which uses per_cpu data if available else falls back to slower
of_get_cpu_node()).

Cc: devicetree@vger.kernel.org
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Reviewed-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Reviewed-by: default avatarRob Herring <robh@kernel.org>
Signed-off-by: default avatarSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent 82975c46

drivers/of/base.c

+26 −0
Original line number Diff line number Diff line
@@ -315,6 +315,32 @@ struct device_node *of_get_cpu_node(int cpu, unsigned int *thread) 
}

EXPORT_SYMBOL(of_get_cpu_node);



/**

 * of_cpu_node_to_id: Get the logical CPU number for a given device_node

 *

 * @cpu_node: Pointer to the device_node for CPU.

 *

 * Returns the logical CPU number of the given CPU device_node.

 * Returns -ENODEV if the CPU is not found.

 */

int of_cpu_node_to_id(struct device_node *cpu_node)

{

	int cpu;

	bool found = false;

	struct device_node *np;



	for_each_possible_cpu(cpu) {

		np = of_cpu_device_node_get(cpu);

		found = (cpu_node == np);

		of_node_put(np);

		if (found)

			return cpu;

	}



	return -ENODEV;

}

EXPORT_SYMBOL(of_cpu_node_to_id);



/**

 * __of_device_is_compatible() - Check if the node matches given constraints

 * @device: pointer to node

include/linux/of.h

+7 −0
Original line number Diff line number Diff line
@@ -544,6 +544,8 @@ const char *of_prop_next_string(struct property *prop, const char *cur); 


bool of_console_check(struct device_node *dn, char *name, int index);



extern int of_cpu_node_to_id(struct device_node *np);



#else /* CONFIG_OF */



static inline void of_core_init(void)
@@ -916,6 +918,11 @@ static inline void of_property_clear_flag(struct property *p, unsigned long flag 
{

}



static inline int of_cpu_node_to_id(struct device_node *np)

{

	return -ENODEV;

}



#define of_match_ptr(_ptr)	NULL

#define of_match_node(_matches, _node)	NULL

#endif /* CONFIG_OF */