Messages in this thread | | | Subject | Re: [PATCH v2 5/7] perf cs-etm: Add helper cs_etm__get_pid_fmt() | From | Suzuki K Poulose <> | Date | Tue, 2 Feb 2021 23:19:22 +0000 |
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On 2/2/21 4:38 PM, Leo Yan wrote: > This patch adds helper function cs_etm__get_pid_fmt(), by passing > parameter "traceID", it returns the PID format. > > Signed-off-by: Leo Yan <leo.yan@linaro.org> > --- > tools/perf/util/cs-etm.c | 43 ++++++++++++++++++++++++++++++++++++++++ > tools/perf/util/cs-etm.h | 1 + > 2 files changed, 44 insertions(+) > > diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c > index a2a369e2fbb6..8194ddbd01e5 100644 > --- a/tools/perf/util/cs-etm.c > +++ b/tools/perf/util/cs-etm.c > @@ -7,6 +7,7 @@ > */ > > #include <linux/bitops.h> > +#include <linux/coresight-pmu.h> > #include <linux/err.h> > #include <linux/kernel.h> > #include <linux/log2.h> > @@ -156,6 +157,48 @@ int cs_etm__get_cpu(u8 trace_chan_id, int *cpu) > return 0; > } > > +/* > + * The returned PID format is presented by two bits: > + * > + * Bit ETM_OPT_CTXTID: CONTEXTIDR or CONTEXTIDR_EL1 is traced; > + * Bit ETM_OPT_CTXTID2: CONTEXTIDR_EL2 is traced. > + * > + * It's possible that these two bits are set together, this means the tracing > + * contains PIDs for both CONTEXTIDR_EL1 and CONTEXTIDR_EL2.
This is a bit confusing. If both the bits are set, the session was run on an EL2 kernel. Thus, the PID is always in CONTEXTIDR_EL2.
> + */ > +int cs_etm__get_pid_fmt(u8 trace_chan_id, u64 *pid_fmt) > +{ > + struct int_node *inode; > + u64 *metadata, val; > + > + inode = intlist__find(traceid_list, trace_chan_id); > + if (!inode) > + return -EINVAL; > + > + metadata = inode->priv; > + > + if (metadata[CS_ETM_MAGIC] == __perf_cs_etmv3_magic) { > + val = metadata[CS_ETM_ETMCR]; > + /* CONTEXTIDR is traced */ > + if (val & BIT(ETM_OPT_CTXTID)) > + *pid_fmt = BIT(ETM_OPT_CTXTID); > + } else { > + val = metadata[CS_ETMV4_TRCCONFIGR]; > + > + *pid_fmt = 0; > + > + /* CONTEXTIDR_EL2 is traced */ > + if (val & (BIT(ETM4_CFG_BIT_VMID) | BIT(ETM4_CFG_BIT_VMID_OPT))) > + *pid_fmt = BIT(ETM_OPT_CTXTID2); > + > + /* CONTEXTIDR_EL1 is traced */ > + if (val & BIT(ETM4_CFG_BIT_CTXTID))
I haven't looked at how this gets used. But, Shouldn't this be :
else if (val & BIT(ETM4_CFG_BIT_CTXTID)) ?
Suzuki
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