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Commit 72210227 authored by Chunyan Zhang's avatar Chunyan Zhang Committed by Greg Kroah-Hartman
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Coresight: Add an interface for supporting ETM3/4 Context ID tracing 



If PID namespace is enabled, everytime users configure the Context ID
register to trace the specific process, there needs to be a translation
between the real PID seen from the kernel and VPID seen from the
namespace in which the user's process resides .

This patch just adds the translation interface for ETMs.

Signed-off-by: default avatarChunyan Zhang <zhang.chunyan@linaro.org>
Signed-off-by: default avatarMathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent cd196ac3

include/linux/coresight.h

+20 −0
Original line number Diff line number Diff line
@@ -248,4 +248,24 @@ static inline struct coresight_platform_data *of_get_coresight_platform_data( 
	struct device *dev, struct device_node *node) { return NULL; }

#endif



#ifdef CONFIG_PID_NS

static inline unsigned long

coresight_vpid_to_pid(unsigned long vpid)

{

	struct task_struct *task = NULL;

	unsigned long pid = 0;



	rcu_read_lock();

	task = find_task_by_vpid(vpid);

	if (task)

		pid = task_pid_nr(task);

	rcu_read_unlock();



	return pid;

}

#else

static inline unsigned long

coresight_vpid_to_pid(unsigned long vpid) { return vpid; }

#endif



#endif