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perf cs-etm: Detect pid in VMID for kernel running at EL2

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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: Suzuki K Poulose <suzuki.poulose@arm.com>
Co-developed-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Mathieu 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: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Suzuki K Poulose 2021-02-24 09:48:35 -07:00 committed by Arnaldo Carvalho de Melo
parent 47f0d94c20
commit 8e1488a46d
1 changed files with 34 additions and 4 deletions
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38
tools/perf/util/cs-etm-decoder/cs-etm-decoder.c
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@ -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)
/*
* 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;
tid = elem->context.context_id;
if (cs_etm__etmq_set_tid(etmq, tid, trace_chan_id))
return OCSD_RESP_FATAL_SYS_ERR;