Commit 8e1488a4 authored by Suzuki K Poulose's avatar Suzuki K Poulose Committed by Arnaldo Carvalho de Melo
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perf cs-etm: Detect pid in VMID for kernel running at EL2 



The PID of the task could be traced as VMID when the kernel is running
at EL2.  Teach the decoder to look for VMID when the CONTEXTIDR (Arm32)
or CONTEXTIDR_EL1 (Arm64) is invalid but we have a valid VMID.

Signed-off-by: default avatarSuzuki K Poulose <suzuki.poulose@arm.com>
Co-developed-by: default avatarLeo Yan <leo.yan@linaro.org>
Reviewed-by: default avatarMathieu Poirier <mathieu.poirier@linaro.org>
Cc: Al Grant <al.grant@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Link: https://lore.kernel.org/r/20210213113220.292229-6-leo.yan@linaro.org
Link: https://lore.kernel.org/r/20210224164835.3497311-7-mathieu.poirier@linaro.org


Signed-off-by: default avatarLeo Yan <leo.yan@linaro.org>
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 47f0d94c

tools/perf/util/cs-etm-decoder/cs-etm-decoder.c

+34 −4
Original line number Diff line number Diff line
@@ -6,6 +6,7 @@ 
 * Author: Mathieu Poirier <mathieu.poirier@linaro.org>

 */



#include <linux/coresight-pmu.h>

#include <linux/err.h>

#include <linux/list.h>

#include <linux/zalloc.h>
@@ -491,13 +492,42 @@ cs_etm_decoder__set_tid(struct cs_etm_queue *etmq, 
			const ocsd_generic_trace_elem *elem,

			const uint8_t trace_chan_id)

{

	pid_t tid;

	pid_t tid = -1;

	static u64 pid_fmt;

	int ret;



	/* Ignore PE_CONTEXT packets that don't have a valid contextID */

	if (!elem->context.ctxt_id_valid)

		return OCSD_RESP_CONT;

	/*

	 * As all the ETMs run at the same exception level, the system should

	 * have the same PID format crossing CPUs.  So cache the PID format

	 * and reuse it for sequential decoding.

	 */

	if (!pid_fmt) {

		ret = cs_etm__get_pid_fmt(trace_chan_id, &pid_fmt);

		if (ret)

			return OCSD_RESP_FATAL_SYS_ERR;

	}



	/*

	 * Process the PE_CONTEXT packets if we have a valid contextID or VMID.

	 * If the kernel is running at EL2, the PID is traced in CONTEXTIDR_EL2

	 * as VMID, Bit ETM_OPT_CTXTID2 is set in this case.

	 */

	switch (pid_fmt) {

	case BIT(ETM_OPT_CTXTID):

		if (elem->context.ctxt_id_valid)

			tid = elem->context.context_id;

		break;

	case BIT(ETM_OPT_CTXTID2):

		if (elem->context.vmid_valid)

			tid = elem->context.vmid;

		break;

	default:

		break;

	}



	if (tid == -1)

		return OCSD_RESP_CONT;



	if (cs_etm__etmq_set_tid(etmq, tid, trace_chan_id))

		return OCSD_RESP_FATAL_SYS_ERR;